John V Conte

Publications (147)800.5 Total impact

• Article: Septuagenarians Bridged to Heart Transplantation With a Ventricular Assist Device Have Outcomes Similar to Younger Patients.

  Timothy J George, Arman Kilic, Claude A Beaty, John V Conte, Kaushik Mandal, Ashish S Shah
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  ABSTRACT: BACKGROUND: Although orthotopic heart transplantation (OHT) is increasingly being offered to older patients, few studies have evaluated outcomes in patients older than 70 years of age. We undertook this study to characterize the outcomes of septuagenarians bridged to transplantation (BTT) in the modern era. METHODS: We conducted a retrospective cohort study of all adult OHT in the United Network for Organ Sharing database from 2005 to 2011. Primary stratification was by age 70 years or older. Subgroup analysis evaluated patients who received BTT. The primary outcome was survival as determined by the Kaplan-Meier method. RESULTS: From January 2005 to December 2011, 12,274 adults underwent OHT, including 3,243 (26.4%) who received BTT. In the entire cohort, 11,996 (97.7%) recipients were aged 18 to 70 years, and 277 (2.3%) were 70 years of age or older. Overall, patients 70 years or older who underwent OHT had decreased 90-day survival (93.6% versus 88.8%; p < 0.01), 1-year survival (89.0% versus 81.6%; p < 0.01), and 2-year survival (85.4% versus 79.9%; p < 0.01) compared with recipients of other ages. However in the BTT subgroup, recipients 70 years and older (n = 43) had similar 90-day (91.2% versus 84.7%; p = 0.2), 1-year (86.1% versus 81.7%; p = 0.4), and 2-year (82.8% versus 81.7%; p = 0.6) survival compared with recipients of other ages (n = 3,200). After adjusting for multiple recipient and donor factors, age greater than or equal to 70 years was still not associated with an increased hazard of mortality at 90 days, 1 year, or 2 years. These results were verified by analysis of a propensity-matched cohort. CONCLUSIONS: Although patients older than the age of 70 years undergoing OHT have decreased survival, among patients who received BTT, septuagenarians have outcomes similar to those of younger recipients. In carefully selected patients dependent on left ventricular assist devices (LVADs), recipient age greater than or equal to 70 years should not be viewed as a contraindication to OHT.
  The Annals of thoracic surgery 02/2013; · 3.74 Impact Factor
• Article: Ventricular Assist Device Implantation in the Elderly: Nationwide Outcomes in the United States.

  Arman Kilic, Ibrahim Sultan, David D Yuh, Ashish S Shah, William A Baumgartner, Duke E Cameron, John V Conte
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  ABSTRACT: BACKGROUND: The aim of this study was to evaluate nationwide outcomes of ventricular assist device (VAD) implantation in elderly patients in the United States. METHODS: Patients undergoing VAD implantation between 2003 and 2008 were identified in the Nationwide Inpatient Sample. The primary outcome was inpatient mortality following VAD implantation. Secondary outcomes included disposition following discharge and costs of care. After stratification based on primary versus postcardiotomy VAD support, outcomes were compared between controls aged 60-69 years and elderly patients aged ≥70 years. RESULTS: A total of 2787 patients aged 60-69 years and 1472 patients aged ≥70 years underwent VAD implantation during the study period. Unadjusted mortality rates were comparable between elderly and control patients in both primary support (35.7% vs. 32.1%, p = 0.61) and postcardiotomy support (58.1% vs. 56.1%, p = 0.70). Similarly, in risk-adjusted multivariable logistic regression analysis incorporating clinically relevant variables, age ≥70 did not exert an independent effect on inpatient mortality for either indication. Inpatient costs in the elderly were lower than controls in the primary support cohort, although costs per day were similar, with comparable overall costs between age groups in the postcardiotomy cohort. Elderly survivors were discharged to a facility more frequently than control survivors (primary: 49.9% vs. 29.6%, p = 0.007; postcardiotomy: 67.4% vs. 45.7%, p = 0.03). CONCLUSIONS: This large-cohort population-based analysis provides a useful framework for inpatient prognosis and resource utilization in elderly patients undergoing VAD implantation. Although mortality rates and costs were found to be comparable between elderly patients and those aged 60-69 years, these rates were nonetheless significant. This combined with more frequent discharge-to-facility in elderly survivors underscores the importance of careful patient selection in this population.
  Journal of Cardiac Surgery 02/2013; · 0.87 Impact Factor
• Article: Pre-transplant malignancy: An analysis of outcomes after thoracic organ transplantation.

  Claude A Beaty, Timothy J George, Arman Kilic, John V Conte, Ashish S Shah
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  ABSTRACT: BACKGROUND: Pre-transplant malignancy (PTM) is a relative contraindication to organ transplantation. Studies examining the effect of PTM on outcomes after lung transplantation (LTx) or orthotopic heart transplantation (OHT) are limited. We evaluated the effect of PTM on outcomes after LTx and OHT. METHODS: We retrospectively reviewed primary adult LTx and OHT recipients in the United Network for Organ Sharing database. Primary stratification was by PTM and secondary stratification by tumor type. Matched cohorts (2:1) and multivariable Cox proportional hazards regression models were used to evaluate mortality. RESULTS: From 2000 to 2011, 13,613 adults underwent LTx and 19,817 underwent OHT. PTM was present in 740 LTx patients (5.4%) and in 1,117 OHT patients (5.6%). On unadjusted analysis, LTx patients and OHT patients with PTM had similar 30-day, 1-year, and 5-year survivals (p<0.05) compared with patients with no PTM. These findings persisted after risk-adjustment. No tumor types were associated with increased mortality in LTx patients. OHT patients with leukemia, lymphoma, or myeloma (LLM) had a significant increase in univariate mortality at 30 days (hazard ratio [HR], 1.82; p = 0.04), 1 year (HR, 1.93; p<0.001), and 5 years (HR, 1.54; p = 0.01). Matched cohort analysis revealed comparable outcomes in LTx patients but confirmed increased univariate 1-year mortality (HR, 1.89; p = 0.006) in OHT patients with LLM. CONCLUSIONS: This large study evaluating the effects of PTM found the incidence of PTM was in LTx 5.4% and in OHT 5.6%. In general, PTM does not increase mortality in either cohort; however, OHT patients with LLM have an increased hazard of mortality. Therefore, carefully selected patients with PTM should not be excluded from LTx or OHT.
  The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 12/2012; · 3.54 Impact Factor
• Article: The effect of center volume on the incidence of postoperative complications and their impact on survival after lung transplantation.

  Arman Kilic, Timothy J George, Claude A Beaty, Christian A Merlo, John V Conte, Ashish S Shah
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  ABSTRACT: OBJECTIVE: The aim of this study was to evaluate the effect of center volume on the incidence of postoperative complications and their impact on survival after lung transplantation (LTx). METHODS: United Network for Organ Sharing data were used to identify adult patients undergoing LTx between 1999 and 2009. Center volume was modeled as both a continuous and a categorical variable. Postoperative complications included infection, rejection, stroke, reoperation, and renal failure requiring dialysis. Multivariable Cox regression and Kaplan-Meier analyses were conducted after stratification on the basis of center volume and type of complication. RESULTS: A total of 12,565 LTx recipients were included in the study. Overall rates of postoperative complications were 5.4% for renal failure requiring dialysis, 1.9% for stroke, 19.9% for reoperation, 42.8% for infection, and 10.0% for rejection. High volume centers did not have significantly reduced rates of postoperative complications. Risk-adjusted multivariable Cox analysis demonstrated that in patients with a complication, low volume center was a significant risk factor for increased 90-day, 1-year, and 5-year mortality. Kaplan-Meier analyses similarly demonstrated reduced posttransplant survival in lower volume centers, a finding that persisted after stratification based on individual complication type except for stroke. CONCLUSIONS: Although high volume centers do not have significantly lower incidences of individual postoperative complications after LTx, they are best able to minimize the adverse effects of these complications on short- and long-term survival. These data suggest that identifying and implementing the institutional practices that lead to better management of postoperative complications after LTx in high volume centers may be prudent to improving outcomes in lower volume hospitals.
  The Journal of thoracic and cardiovascular surgery 09/2012; · 3.41 Impact Factor
• Article: Institutional factors beyond procedural volume significantly impact center variability in outcomes after orthotopic heart transplantation.

  Arman Kilic, Eric S Weiss, David D Yuh, Ashish S Shah, Duke E Cameron, William A Baumgartner, John V Conte
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  ABSTRACT: : To evaluate the contribution of institutional volume and other unmeasured institutional factors beyond volume to the between-center variability in outcomes after orthotopic heart transplantation (OHT). : It is unclear if institutional factors beyond volume have a significant impact on OHT outcomes. : The United Network for Organ Sharing registry was used to identify OHTs performed between 2000 and 2010. Separate mixed-effect logistic regression models were constructed, with the primary endpoint being post-OHT mortality. Model A included only individual centers, model B added validated recipient and donor risk indices as well as the year of transplantation, and model C added institutional volume as a continuous variable to model B. The reduction in between-center variability in mortality between models B and C was used to define the contribution of institutional volume. Kaplan-Meier survival curves were also compared after stratifying patients into equal-size tertiles based on center volume. : A total of 119 centers performed OHT in 19,156 patients. After adjusting for transplantation year and differences in recipient and donor risk, decreasing center volume was associated with an increased risk of 1-year mortality (P < 0.001). However, procedural volume only accounted for 16.7% of the variability in mortality between centers, and significant between-center variability persisted after adjusting for institutional volume (P<0.001). In Kaplan-Meier analysis, there was significant variability in 1-year survival between centers within each volume category: low-volume (66.7%-96.6%), intermediate-volume (80.7%-97.3%), and high-volume (83.8%-93.9%). These trends were also observed with 5-year mortality. : This large-cohort analysis demonstrates that although institutional volume is a significant predictor of post-OHT outcomes, there are other unmeasured institutional factors that contribute substantially to the between-center variability in outcomes. Institutional volume should therefore not be the sole indicator of "center quality" in OHT.
  Annals of surgery 09/2012; 256(4):616-23. · 7.90 Impact Factor
• Article: Reoperative Sternotomy Is Associated With Increased Mortality After Heart Transplantation.

  Timothy J George, Claude A Beaty, Gregory A Ewald, Stuart D Russell, Ashish S Shah, John V Conte, Glenn J Whitman, Scott C Silvestry
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  ABSTRACT: BACKGROUND: Although several studies have examined factors affecting survival after orthotopic heart transplantation (OHT), few have evaluated the impact of reoperative sternotomy. We undertook this study to examine the incidence and impact of repeat sternotomies on OHT outcomes. METHODS: We conducted a retrospective review of all adult OHT from 2 institutions. Primary stratification was by the number of prior sternotomies. The primary outcome was survival. Secondary outcomes included blood product utilization and commonly encountered postoperative complications. Multivariable Cox proportional hazards regression models examined mortality while linear regression models examined blood utilization. RESULTS: From January 1995 to October 2011, 631 OHT were performed. Of these, 25 (4.0%) were redo OHT and 182 (28.8%) were bridged to transplant with a ventricular assist device; 356 (56.4%) had undergone at least 1 prior sternotomy. On unadjusted analysis, reoperative sternotomy was associated with decreased 90-day (98.5% vs 90.2%, p < 0.001), 1-year (93.1% vs 79.6%, p < 0.001), and 5-year (80.4% vs 70.1%, p = 0.002) survival. This difference persisted on multivariable analysis at 90 days (hazard ratio [HR] 2.99, p = 0.01), 1 year (HR 2.98, p = 0.002), and 5 years (HR 1.62, p = 0.049). The impact of an increasing number of prior sternotomies was negligible. On multivariable analysis, an increasing number of prior sternotomies was associated with increased intraoperative blood product utilization. Increasing blood utilization was associated with decreased 90-day, 1-year, and 5-year survival. CONCLUSIONS: Reoperative sternotomy is associated with increased mortality and blood utilization after OHT. Patients with more than 1 prior sternotomy do not experience additional increased mortality. Carefully selected patients with multiple prior sternotomies have decreased but acceptable outcomes.
  The Annals of thoracic surgery 09/2012; · 3.74 Impact Factor
• Article: The spectrum of complications following left ventricular assist device placement.

  Nance Yuan, George J Arnaoutakis, Timothy J George, Jeremiah G Allen, Derek G Ju, Justin M Schaffer, Stuart D Russell, Ashish S Shah, John V Conte
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  ABSTRACT: Abstract  Introduction: Left ventricular assist device (LVAD) support is associated with many complications, but relatively few studies have examined the full spectrum of complications beyond infectious and bleeding events. Methods: We conducted a retrospective review of patients receiving either a pulsatile-flow Heartmate XVE (HM1; Thoratec Corp., Pleasanton, CA, USA) or continuous-flow Heartmate II (HM2; Thoratec Corp.) LVAD at our institution (June 2000 to March 2012). Frequency and date of onset of nonbleeding, noninfectious complications were examined. Results: One hundred eighty-two LVADs were implanted, 49 HM1, and 133 HM2. Support duration was longer for HM2s (median 358 vs. 112 days; p = 0.0003). Overall, the most frequent complications were respiratory failure, ventricular arrhythmia, atrial arrhythmia, right heart failure, and renal failure. Respiratory failure, arrhythmias, severe psychiatric events, and renal failure all occurred with median date of onset ≤ seven days postprocedure. Right heart failure, hepatic failure, thromboembolism, and transient ischemic attacks had a median date of onset 8 to 30 days postprocedure. Stroke, hemolysis, and device failure occurred mostly more than a month postoperatively. Right heart failure, hepatic failure, and device failure were more frequent in HM1 patients than in HM2 patients. Several events, including stroke, had much later onset in HM2 patients. Conclusion: In this 10-year review of complications following LVAD implantation, the most common adverse events tended to occur early after implantation. As pulsatile-flow HM1s showed greater frequency and earlier onset of some adverse events, our data suggest better overall outcomes with the continuous-flow HM2s. (J Card Surg 2012;27:630-638).
  Journal of Cardiac Surgery 09/2012; 27(5):630-8. · 0.87 Impact Factor
• Article: Lung transplantation in patients 70 years old or older: Have outcomes changed after implementation of the lung allocation score?

  Arman Kilic, Christian A Merlo, John V Conte, Ashish S Shah
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  ABSTRACT: The objective of the present study was to evaluate whether the outcomes of lung transplantation in patients aged 70 years or older have changed after implementation of the lung allocation score in May 2005. Patients aged 70 years or older undergoing primary lung transplantation from 1995 to 2009 were identified from the United Network for Organ Sharing registry. The primary stratification was the pre-lung allocation score era versus lung allocation score era. Risk-adjusted multivariate Cox regression and Kaplan-Meier analyses were conducted to evaluate the effect of age 70 years or older on 1-year post-transplant mortality compared with a reference cohort of patients aged 60 to 69 years. Of the overall 15,726 adult lung transplantation patients in the study period, 225 (1.4%) were 70 years old or older and 4634 (29.5%) were 60 to 69 years old. The patients aged 70 years or older were a larger cohort of overall lung transplantation patients in the lung allocation score era compared with before the lung allocation score era (3.1% vs 0.3%, P < .001). In the risk-adjusted Cox analysis, age 70 years or older was a significant risk factor for 1-year post-lung transplantation mortality in the pre-lung allocation score era (hazard ratio, 2.00; 95% confidence interval, 1.10-3.62, P = .02) but not in the lung allocation score era (hazard ratio, 1.02; 95% confidence interval, 0.71-1.46; P = .92). Similarly, Kaplan-Meier 1-year survival was significantly reduced in patients 70 years old or older versus 60 to 69 years old in the pre-lung allocation score era (56.7% vs 76.3%, P = .006) but not in the lung allocation score era (79.0% vs 80.0%, P = .72). Recipients aged 70 years or older were a larger proportion of overall lung transplantation patients after implementation of the lung allocation score. Although associated with significantly increased post-lung transplantation mortality in the pre-lung allocation score era, age 70 years or older is currently associated with outcomes comparable to those of patients aged 60 to 69 years. Therefore, age 70 years or older should not serve as an absolute contraindication to lung transplantation in the lung allocation score era.
  The Journal of thoracic and cardiovascular surgery 08/2012; 144(5):1133-8. · 3.41 Impact Factor
• Article: Operative outcomes in mitral valve surgery: Combined effect of surgeon and hospital volume in a population-based analysis.

  Arman Kilic, Ashish S Shah, John V Conte, William A Baumgartner, David D Yuh
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  ABSTRACT: OBJECTIVE: We evaluated the combined effect of hospital and surgeon volume on operative outcomes of mitral valve surgery in the United States. METHODS: The Nationwide Inpatient Sample was used to identify adult patients undergoing isolated mitral valve surgery for mitral regurgitation from 2003 to 2008. Hospitals and surgeons were separately stratified into equal-size tertiles according to annual overall mitral valve operative volumes. Multivariate logistic regression analysis was conducted, adjusting for multiple patient, hospital, and operative data, to determine the separate and combined effects of hospital and surgeon volume on operative outcomes. RESULTS: A total of 50,152 eligible patients were identified during the study period. Although both hospital and surgeon volume correlated significantly with operative mortality in separate risk-adjusted analyses, only lower surgeon volume persisted as a significant risk factor in the combined risk-adjusted analysis. Moreover, although hospital volume only accounted for 10.7% of the surgeon volume effect on increased mortality for low-volume surgeons, surgeon volume accounted for 74.5% of the hospital volume effect on increased mortality in low-volume hospitals. Surgeon, but not hospital, volume correlated with inpatient costs. Also, significant trends were seen with repair rates, with increasing surgeon volume demonstrating a relatively stronger correlation with the odds of repair (P < .001) than hospital volume (P = .01). CONCLUSIONS: The effect of hospital volume on operative outcomes of mitral valve surgery was largely driven by the individual surgeon volumes within that hospital. Conversely, surgeon volume affected these outcomes independently of hospital volume. Identifying the processes by which higher volume surgeons attain better outcomes in mitral valve surgery would therefore be prudent.
  The Journal of thoracic and cardiovascular surgery 08/2012; · 3.41 Impact Factor
• Article: Should Patients 60 Years and Older Undergo Bridge to Transplantation With Continuous-Flow Left Ventricular Assist Devices?

  Jeremiah G Allen, Arman Kilic, Eric S Weiss, George J Arnaoutakis, Timothy J George, Ashish S Shah, John V Conte
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  ABSTRACT: BACKGROUND: Although left ventricular assist devices (LVADs) are now commonly used as a bridge to orthotopic heart transplantation (OHT), the upper patient age limit for this therapy has not been defined. Smaller studies have suggested that advanced age should not be a contraindication to bridge to transplantation (BTT) LVAD placement. The purpose of this study was to examine outcomes in patients 60 years and older undergoing BTT with continuous-flow LVADs. METHODS: The United Network for Organ Sharing (UNOS) database was reviewed to identify first-time OHT recipients 60 years of age and older (2005-2010). Patients were stratified by preoperative support: continuous-flow LVAD, intravenous inotropic agents, and direct transplantation. Survival after OHT was modeled using the Kaplan-Meier method. All-cause mortality was examined using multivariable Cox proportional hazard regression. RESULTS: Of 2,554 patients, 1,142 (44.7%) underwent direct transplantation, 264 (10.3%) had LVAD BTT, and 1,148 (45.0%) had BTT with inotropic agents. The mean age was 64 ± 3 years, and 460 (18.0%) patients were women. Mean follow-up was 29 ± 19 months. Survival differed significantly among the 3 groups. Patients with LVAD BTT had significantly lower survival after OHT compared with the other groups at 30 days and 1 year. This survival difference was no longer significant at 2 years after OHT or when deaths in the first 30 days were censored. LVAD BTT increased the hazard of death at 1 year by 50% (hazard ratio [HR], 1.50; 95% confidence interval [CI], 1.05-2.15; p = 0.03), compared with patients who underwent direct transplantation. CONCLUSIONS: This study represents the largest modern cohort in which survival after OHT has been evaluated in patients 60 years or older who received BTT. Older patients have lower short-term survival after OHT when BTT is carried out with a continuous-flow LVAD compared with inotropic agents or direct transplantation.
  The Annals of thoracic surgery 08/2012; · 3.74 Impact Factor
• Article: Simple score to assess the risk of rejection after orthotopic heart transplantation.

  Arman Kilic, Eric S Weiss, Jeremiah G Allen, John V Conte, Ashish S Shah, William A Baumgartner, David D Yuh
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  ABSTRACT: The aim of this study was to derive and validate a risk score for rejection after orthotopic heart transplantation. The United Network for Organ Sharing registry was used to identify patients undergoing orthotopic heart transplantation between 1998 and 2008. A total of 14 265 eligible patients were randomly divided into derivation (80%; n=11 412) and validation (20%; n=2853) cohorts. The primary outcome was drug-treated rejection within 1 year of orthotopic heart transplantation. Covariates found to be associated (exploratory univariate P<0.2) with rejection were entered into a multivariable logistic regression model. Inclusion of each variable in the model was assessed by improvement in the McFadden pseudo-R(2), likelihood ratio test, and c index. A risk score was then generated through the use of relative magnitudes of the odds ratios from the derivation cohort, and its ability to predict rejection was tested independently in the validation cohort. A 13-point risk score incorporating 4 variables (age, race, sex, HLA matching) was created. The mean scores in the derivation and validation cohorts were 8.3±2.2 and 8.4±2.1, respectively. Predicted 1-year rejection rates based on the derivation cohort ranged from 16.2% (score=0) to 50.7% (score=13; P<0.001). In weighted regression analysis, there was a strong correlation between these predicted rates of rejection and actual, observed rejection rates in the validation cohort (r(2)=0.96, P<0.001). Logistic regression analysis also demonstrated a significant association (odds ratio, 1.13; P<0.001). The c index of the composite score was equivalent in both the derivation and validation cohorts (c=0.67). This novel 13-point risk score is highly predictive of clinically significant rejection episodes within 1 year of orthotopic heart transplantation. It has potential utility in tailoring immunosuppressive regimens and in research stratification in orthotopic heart transplantation.
  Circulation 05/2012; 125(24):3013-21. · 14.74 Impact Factor
• Article: Surgical repair of ventricular septal defect after myocardial infarction: outcomes from the Society of Thoracic Surgeons National Database.

  George J Arnaoutakis, Yue Zhao, Timothy J George, Christopher M Sciortino, Patrick M McCarthy, John V Conte
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  ABSTRACT: The development of a ventricular septal defect (VSD) after myocardial infarction (MI) is an uncommon but highly lethal complication. We examined The Society of Thoracic Surgeons database to characterize patients undergoing surgical repair of post-MI VSD and to identify risk factors for poor outcomes. This was a retrospective review of The Society of Thoracic Surgeons database to identify adults (aged≥18 years) who underwent post-MI VSD repair between 1999 and 2010. Patients with congenital heart disease were excluded. The primary outcome was operative death. The covariates in the current The Society of Thoracic Surgeons model for predicted coronary artery bypass grafting operative death were incorporated in a logistic regression model in this cohort. The study included 2,876 patients (1,624 men [56.5%]), who were a mean age of 68±11 years. Of these, 215 (7.5%) had prior coronary artery bypass grafting operations, 950 (33%) had prior percutaneous intervention, and 1,869 (65.0%) were supported preoperatively with an intraaortic balloon pump. Surgical status was urgent in 1,007 (35.0%) and emergencies in 1,430 (49.7%). Concomitant coronary artery bypass grafting was performed in 1,837 (63.9%). Operative mortality was 54.1% (1,077 of 1,990) if repair was within 7 days from MI and 18.4% (158 of 856) if more than 7 days from MI. Multivariable analysis identified several factors associated with increased odds of operative death. In the largest study to date to examine post-MI VSD repair, ventricular septal rupture remains a devastating complication. As alternative therapies emerge to treat this condition, these results will serve as a benchmark for future comparisons.
  The Annals of thoracic surgery 05/2012; 94(2):436-43; discussion 443-4. · 3.74 Impact Factor
• Article: Should orthotopic heart transplantation using marginal donors be limited to higher volume centers?

  Arman Kilic, Eric S Weiss, Jeremiah G Allen, Timothy J George, David D Yuh, Ashish S Shah, John V Conte
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  ABSTRACT: This study examined whether institutional volume impacts outcomes after orthotopic heart transplantation (OHT) utilizing marginal donors. Adult patients undergoing OHT with the use of marginal donors between 2000 and 2010 were identified in the United Network for Organ Sharing database. A previously derived and validated donor risk score (range, 1 to 15) was used to define marginal donors as those in the 90th percentile of risk (score≥7). Patients were stratified into equal-size tertiles based on overall institutional OHT volume. Posttransplant outcomes were compared between these center cohorts. A total of 3,176 OHTs utilizing marginal donors were identified. In Cox regression analysis, recipients undergoing OHT at low-volume centers were at significantly increased risk of 30-day (hazard ratio 1.82 [1.31 to 2.54], p<0.001), 1-year (hazard ratio 1.40 [1.14 to 1.73], p=0.002), and 5-year posttransplant mortality (hazard ratio 1.29 [1.10 to 1.52], p=0.02). These findings persisted after adjusting for recipient risk, differences in donor risk score, and year of transplantation (each p<0.05). In Kaplan-Meier analysis, there was a similar trend of decreasing 1-year survival with decreasing center volume: high (86.0%), intermediate (85.7%), and low (81.2%; log rank p=0.003). Drug-treated rejection within the first post-OHT year was more common in low-volume versus high-volume centers (34.3% versus 24.2%, p<0.001). At an overall mean follow-up of 3.4±2.9 years, low-volume centers also had higher incidences of death due to malignancy (2.8% versus 1.3%, p=0.01) or infection (6.2% versus 4.1%, p=0.02). Consolidating the use of marginal donors to higher volume centers may be prudent in improving post-OHT outcomes in this higher risk patient subset.
  The Annals of thoracic surgery 05/2012; 94(3):695-702. · 3.74 Impact Factor
• Article: Contemporary etiologies, risk factors, and outcomes after pericardiectomy.

  Timothy J George, George J Arnaoutakis, Claude A Beaty, Arman Kilic, William A Baumgartner, John V Conte
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  ABSTRACT: The leading causes of constrictive pericarditis have changed over time leading to a commensurate change in the indications and complexity of surgical pericardiectomy. We evaluated our single-center experience to define the etiologies, risk factors, and outcomes of pericardiectomy in a modern cohort. We retrospectively reviewed our institutional database for all patients who underwent total or partial pericardiectomy. Demographic, comorbid, operative, and outcome data were evaluated. Survival was assessed by the Kaplan-Meier method. Multivariable Cox proportional hazards regression models examined risk factors for mortality. From 1995 to 2010, 98 adults underwent pericardiectomy for constrictive disease. The most common etiologies were idiopathic (n=44), postoperative (n=30), and post radiation (n=17). Total pericardiectomy was performed in 94 cases, most commonly through a sternotomy (n=93). Thirty-three cases were redo sternotomies, 34 underwent a concomitant procedure, and 34 required cardiopulmonary bypass. Overall in-hospital, 1-year, 5-year, and 10-year survival rates were 92.9%, 82.5%, 64.3%, and 49.2%, respectively. Survival differed sharply by etiology with idiopathic, postoperative, and post-radiation 5-year survivals of 79.8%, 55.9%, and 11.0%, respectively (p<0.001). On multivariable analysis, only the need for cardiopulmonary bypass (hazard ratio [HR]: 21.2, p=0.02) was predictive of 30-day mortality while post-radiation etiology (HR: 3.19, p=0.02) and hypoalbuminemia (HR: 0.57, p=0.03) were associated with increased 10-year mortality. Although survival varies significantly by etiology, pericardiectomy continues to be a safe operation for constrictive pericarditis. Post-radiation pericarditis and hypoalbuminemia are significant risk factors for decreased long-term survival.
  The Annals of thoracic surgery 05/2012; 94(2):445-51. · 3.74 Impact Factor
• Article: Risk factors for early death in patients bridged to transplant with continuous-flow left ventricular assist devices.

  George J Arnaoutakis, Timothy J George, Arman Kilic, Claude A Beaty, Eric S Weiss, John V Conte, Ashish S Shah
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  ABSTRACT: Recent evidence suggests patients bridged to heart transplant (BTT) have equivalent outcomes as those undergoing conventional orthotopic heart transplantation (OHT). However, data on risk factors for early death in BTT patients are limited. We retrospectively reviewed the United Network for Organ Sharing database of all patients bridged to OHT with a HeartMate II from January 2005 to December 2010. The primary outcome was all-cause 90-day mortality. Additional postoperative outcomes were cerebrovascular accident and need for renal replacement therapy. Kaplan-Meier analysis assessed survival. Preoperative variables associated with 90-day death on univariate analysis (p<0.2) were included in a multivariable Cox proportional hazards regression. A HeartMate II was used to bridge 1,312 patients (average age, 52±12 years) to OHT, most commonly for idiopathic cardiomyopathy (50.7%). During the study, 171 patients (13.0%) died. The unadjusted 90-day survival was 92.3%. The highest annual average center volume in this cohort, examining for BTT recipients only, was 28 BTT procedures yearly. Postoperative cerebrovascular accident occurred in 29 patients (2.2%), and 106 (8.3%) required renal replacement therapy. Cox regression revealed age, glomerular filtration rate, African American race, human leukocyte antigen mismatch, serum bilirubin, need for mechanical ventilation, donor age, and prolonged ischemia time were associated with 90-day death. Early survival was improved for patients who underwent OHT at high-volume centers (p=0.01). This study examining risk factors for early death in patients bridged to OHT using HeartMate II mechanical assistance will aid in identifying patients best suited to benefit from this technology.
  The Annals of thoracic surgery 03/2012; 93(5):1549-54; discussion 1555. · 3.74 Impact Factor
• Article: Orthotopic heart transplantation in patients with metabolic risk factors.

  Arman Kilic, John V Conte, Ashish S Shah, David D Yuh
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  ABSTRACT: The aim of this study was to evaluate the impact of metabolic risk factors on mortality rates after orthotopic heart transplantation (OHT). Adult patients undergoing OHT between 1998 and 2008 were identified in the United Network for Organ Sharing registry. The impact of metabolic risk factors (hypertension, diabetes mellitus, and obesity) on mortality post-OHT was evaluated in a Cox proportional hazards regression analysis adjusted for other variables associated with survival in univariate analysis (exploratory p value<0.2). Kaplan-Meier survival estimates were compared with the log-rank test. A total of 15,960 eligible patients underwent OHT during the study period. There were 6,368 (39.9%) patients with none of these risk factors, 6,138 (38.5%) with 1 risk factor, 2,811 (17.6%) with 2 risk factors, and 643 (4.0%) who had all 3 risk factors. After adjusting for other significant variables influencing survival, each individual risk factor independently increased the likelihood of mortality post-OHT (hypertension: HR 1.10 [1.03 to 1.17]; diabetes: HR 1.22[1.13 to 1.31]; obesity: HR 1.17 [1.10 to 1.26], each p<0.01). There was an exponential trend of increasing mortality with the addition of each risk factor (r2=0.99, p<0.001) such that patients with all 3 risk factors had a 63% increased mortality compared with those with no risk factors (HR 1.63 [1.42 to 1.88], p<0.001). There was also a significant trend in declining 5-year survival rates with an increasing number of risk factors: 0 (74.7%), 1 (71.3%), 2 (68.2%), and 3 (63.1%) (p<0.001). This large-cohort study demonstrates that an increasing number of metabolic risk factors in OHT recipients is associated with exponential increases in postoperative mortality rates.
  The Annals of thoracic surgery 03/2012; 93(3):718-24. · 3.74 Impact Factor
• Article: Identifying recipients at high risk for graft failure after heart retransplantation.

  Arman Kilic, Eric S Weiss, George J Arnaoutakis, Timothy J George, John V Conte, Ashish S Shah, David D Yuh
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  ABSTRACT: The aim of this study was to identify recipient factors that are associated with a high risk of graft failure after heart retransplantation (HRT). The prospectively collected United Network for Organ Sharing registry was used to identify patients undergoing HRT among 24,477 patients who had undergone cardiac transplantation between 1997 and 2009. The primary outcome was graft failure within 1 year of HRT. The impact of 35 recipient variables on the primary outcome was tested in exploratory univariate logistic regression analysis. Those factors found to be significantly associated with graft failure were entered into a multivariable logistic regression model. A total of 671 patients underwent HRT during the study period. Overall, 302 (45%) grafts failed after HRT at a mean follow-up of 4.3±3.7 years. Three recipient factors were found to be associated with 1-year graft failure in the multivariate model: older age, increasing serum creatinine, and mechanical ventilation before HRT. Moreover, each decade increase in recipient age was associated with a 20% increase in odds of 1-year graft failure (odds ratio, 1.02; 95% confidence interval, 1.01 to 1.04; p=0.005). Similarly, each 1-mg/dL increase in serum creatinine increased odds of graft failure by 58% (odds ratio, 1.58; 95% confidence interval, 1.27 to 1.97; p<0.001). Patients who were mechanically ventilated had a fourfold higher likelihood of 1-year graft failure (odds ratio, 4.32; 95% confidence interval, 2.28 to 8.18; p<0.001). The risk of graft failure after HRT increases with an increasing number of significant recipient risk factors, namely older age, increasing serum creatinine, and mechanical ventilation. These risk factors should serve as relative contraindications to HRT, especially when present in combination, given the higher rate of graft failure in these patients.
  The Annals of thoracic surgery 03/2012; 93(3):712-6. · 3.74 Impact Factor
• Article: What predicts long-term survival after heart transplantation? An analysis of 9,400 ten-year survivors.

  Arman Kilic, Eric S Weiss, Timothy J George, George J Arnaoutakis, David D Yuh, Ashish S Shah, John V Conte
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  ABSTRACT: This case-control study was conducted to identify factors predictive of 10-year survival after orthotopic heart transplantation (OHT). Prospectively collected data from the United Network for Organ Sharing registry were reviewed to identify adult patients undergoing OHT between 1987 and 1999 (N=22,385) who had survived 10 years. Controls were those who had died within 10 years of OHT. Factors associated with 10-year survival were identified with multivariate logistic regression analysis. Lowess smoothing plots were used to identify linear breakpoints in continuous variables, and splines were incorporated when appropriate. There were 9,404 ten-year survivors (42%; mean follow-up, 14.0±3.0 years) and 10,373 controls (46%) with a mean survival of 3.7±3.3 years post-OHT. Predictors of 10-year survival in the optimal multivariate model were age younger than 55 (odds ratio [OR], 1.24; 95% confidence interval [CI], 1.10 to 1.38; p<0.001), white race (OR, 1.35; 95% CI, 1.17 to 1.56; p<0.001), shorter ischemic time (OR, 1.11; 95% CI, 1.05 to 1.18; p<0.001), younger donor age (OR, 1.01; 95% CI, 1.01 to 1.02; p<0.001), annual center volume of 9 or more (OR, 1.31; 95% CI, 1.17 to 1.47; p<0.001), mechanical ventilation (OR, 0.53; 95% CI, 0.36 to 0.78; p=0.001), and diabetes (OR, 0.67; 95% CI, 0.57 to 0.78; p<0.001). Age younger than 55 years, annual center volume of 9 or more, white race, shorter ischemic time, and younger donor age improved the likelihood of 10-year survival after OHT. Mechanical ventilation and diabetes reduced this likelihood. These data should serve as a useful guide to long-term prognostication in adult OHT.
  The Annals of thoracic surgery 03/2012; 93(3):699-704. · 3.74 Impact Factor
• Article: Nationwide outcomes of surgical embolectomy for acute pulmonary embolism.

  Arman Kilic, Ashish S Shah, John V Conte, David D Yuh
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  ABSTRACT: OBJECTIVE: The aim of the present study was to review nationwide outcomes of surgical embolectomy for acute pulmonary embolism. METHODS: Adult patients undergoing surgical embolectomy for acute pulmonary embolism from 1999 to 2008 were identified in the weighted Nationwide Inpatient Sample. The primary endpoint was inpatient mortality. Multivariate logistic regression analysis incorporating significant univariate predictors (P < .2) was conducted to identify independent predictors of inpatient mortality. RESULTS: There were 2709 eligible patients identified as undergoing surgical embolectomy for acute pulmonary embolism during the study period. The mean age was 57.0 ± 16.0 years. Of the patients, 1242 (45.8%) were women. A total of 280 patients (10.3%) had undergone thrombolysis before surgical embolectomy. The overall inpatient mortality rate was 27.2%. On multivariate analysis, an increasing Charlson comorbidity index (odds ratio, 1.37; 95% confidence interval, 1.12-1.69; P = .003) significantly increased the odds of inpatient mortality. In addition, blacks were more than twofold more likely to die during hospitalization than whites (odds ratio, 2.29; 95% confidence interval, 1.18-4.46; P = .02). Although age, payment type, hospital location (urban versus rural), hospital embolectomy volume, and surgeon embolectomy volume were associated with inpatient mortality on univariate analysis (each P < .2), none of these factors correlated with mortality in the multivariate model. CONCLUSIONS: This large-cohort analysis of more than 2700 patients demonstrates a nationwide inpatient mortality rate of 27.2% after pulmonary embolectomy. Although patient factors affect mortality, the arena of care appears to have no significant effect on operative outcomes. This suggests that it might be more prudent for centers with qualified surgeons to avoid delays in treatment, rather than transfer care because of a perception of improved outcomes.
  The Journal of thoracic and cardiovascular surgery 02/2012; · 3.41 Impact Factor
• Article: Acute kidney injury increases mortality after lung transplantation.

  Timothy J George, George J Arnaoutakis, Claude A Beaty, Matthew R Pipeling, Christian A Merlo, John V Conte, Ashish S Shah
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  ABSTRACT: Acute kidney injury requiring renal replacement therapy (RRT) is associated with increased mortality after cardiac surgery. Studies examining the impact of RRT after lung transplantation (LTx) are limited. We evaluated risk factors and outcomes associated with RRT after LTx. We retrospectively reviewed all LTx recipients in the United Network for Organ Sharing database. Preoperative renal function was stratified by glomerular filtration rate (GFR) as determined by the Modification of Diet in Renal Disease formula (strata: ≥90, 60 to 90, and <60 mL · min(-1) · 1.73 m(-2)). Primary outcomes were 30-day, 1-year, and 5-year survival and need for post-LTx RRT. Risk adjusted multivariable Cox proportional hazards regression examined mortality. A multivariable logistic regression model evaluated risk factors for RRT. From 2001 to 2011, 12,108 patients underwent LTx. After LTx, 655 patients (5.51%) required RRT. Patients requiring post-LTx RRT had decreased survival at 30 days (96.7% versus 76.0%, p < 0.001), 1 year (85.5% versus 35.8%, p < 0.001), and 5 years (56.4% versus 20.0%, p < 0.001). These differences persisted on multivariable analysis at 30 days (hazard ratio [HR] 7.98 [6.16 to 10.33], p < 0.001), 1 year (HR 7.93 [6.84 to 9.19], p < 0.001), and 5 years (HR 5.39 [4.75 to 6.11], p < 0.001). Preoperative kidney function was an important predictor of post-LTx RRT for a GFR of 60 to 90 (odds ratio 1.42 [1.16 to 1.75], p = 0.001) and a GFR less than 60 (odds ratio 2.68 [2.07 to 3.46], p < 0.001]. High center volume was protective. In the largest study to evaluate acute kidney injury after LTx, the incidence of RRT is 5.51%. The need for post-LTx RRT dramatically increases both short- and long-term mortality. Several variables, including preoperative renal function, are predictors of post-LTx RRT and could be used to identify transplant candidates at risk for acute kidney injury.
  The Annals of thoracic surgery 02/2012; 94(1):185-92. · 3.74 Impact Factor