A S Wechsler

Drexel University College of Medicine, Philadelphia, Pennsylvania, United States

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Publications (286)1323.82 Total impact

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    ABSTRACT: The study objective was to identify the predictors of outcomes in a contemporary cohort of patients from the Reduction in cardiovascular Events by acaDesine in patients undergoing CABG (RED-CABG) trial. Despite the increasing risk profile of patients who undergo coronary artery bypass grafting, morbidity and mortality have remained low, and identification of the current predictors of adverse outcomes may permit new treatments to further improve outcomes.
    Journal of Thoracic and Cardiovascular Surgery 08/2014; · 3.99 Impact Factor
  • Andrew S Wechsler
    The Annals of thoracic surgery 12/2013; 96(6):2285. · 3.45 Impact Factor
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    ABSTRACT: The loss of normal apical rotation is associated with left ventricular (LV) remodeling and systolic dysfunction in patients with congestive heart failure after myocardial infarction. The objective of the present study was to evaluate the effect of epicardial ventricular reconstruction, an off-pump, less-invasive surgical reshaping technique, on myocardial strain, LV twist, and the potential alteration of myocardial fiber orientation in an ovine model of LV anteroapical aneurysm. LV anteroapical myocardial infarction was induced by coil embolization of the left anterior descending artery. Eight weeks after occlusion, epicardial ventricular reconstruction was performed using left thoracotomy under fluoroscopic guidance in 8 sheep to completely exclude the scar. The peak systolic longitudinal/circumferential strains and LV twist were evaluated using speckle tracking echocardiography before (baseline), after device implantation, and at 6 weeks of follow-up. Epicardial ventricular reconstruction was completed in all sheep without any complications. Immediately after device implantation, LV twist significantly increased (4.18 ± 1.40 vs baseline 1.97 ± 1.92; P = .02). The ejection fraction had increased 17% and LV end-systolic volume had decreased 40%. The global longitudinal strain increased from -5.3% to -9.1% (P < .05). Circumferential strain increased in both middle and apical LV segments, with the greatest improvement in the inferior lateral wall (from -11.4% to -20.6%, P < .001). These effects were maintained ≥6 weeks after device implantation without redilation. Less invasive than alternative therapies, epicardial ventricular reconstruction on the off-pump beating heart can restore LV twist and systolic strain and reverse LV remodeling in an ovine anteroapical aneurysm model.
    The Journal of thoracic and cardiovascular surgery 09/2013; · 3.41 Impact Factor
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    ABSTRACT: Surgical ventricular reconstruction has been used to treat ischaemic cardiomyopathy with large akinetic or dyskinetic areas. However, application of this approach requires a sternotomy, cardiopulmonary bypass and a left ventriculotomy. This study assessed the feasibility and efficacy of minimally invasive, off-pump, epicardial catheter-based ventricular reconstruction (ECVR) in an anteroapical aneurysm ovine model. Left ventricular (LV) anteroapical myocardial infarction was induced percutaneously by coil embolization of the left anterior descending coronary artery. Eight weeks after infarction, via mini left thoracotomy and without cardiopulmonary bypass, ECVR was performed in six sheep. The scar was excluded by placing anchor pairs on the LV epicardial anterior wall and the right ventricular side of the interventricular septum under fluoroscopic guidance. LV performance was evaluated before, immediately after device implantation and after 6 weeks by echocardiography. Terminal histopathology was performed. ECVR was completed expeditiously in all animals without complications. Parameters obtained 6 weeks after device implantation were compared with baseline (pre-device). End-systolic volume was decreased by 38% (25.6 ± 6.1 ml vs baseline 41.2 ± 7.2 ml, P = 0.02) with preservation of stroke volume. Ejection fraction was significantly increased by 13% (48.5 ± 7% vs baseline 35.8 ± 7%, P = 0.02). The circumferential strain in the anterior septum (-7.67 ± 5.12% vs baseline -0.96 ± 2.22%, P = 0.03) and anterior wall (-9.01 ± 3.51% vs baseline -4.15 ± 1.36%, P = 0.01) were significantly improved. The longitudinal strain in apex was reversed (-3.08 ± 1.53% vs baseline 3.09 ± 3.39%, P = 0.01). Histopathology showed full endocardial healing over the anchors with appreciable reduction of the chronic infarct in the LV. ECVR without cardiopulmonary bypass is a less invasive alternative to current standard therapies, reverses LV remodelling and improves cardiac performance in an ovine model of anteroapical aneurysm.
    Interactive Cardiovascular and Thoracic Surgery 08/2013; · 1.11 Impact Factor
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    ABSTRACT: OBJECTIVES: We previously presented early results employing a technique designed for beating heart, ventricular volume reduction (surgical ventricular restoration, SVR) without ventriculotomy for patients with antero-septal scar and dilated ischaemic cardiomyopathy. Significant volume reduction and clinical improvement were achieved. We now report durability in the first 11 patients available for assessment at 6 and 12 months after operation. METHODS: After the Ethics Committee approval, 31 symptomatic patients with left ventricular (LV) dilatation and antero-septal scars underwent operation. The scarred lateral LV wall was apposed to the septal scar with serial paired anchors placed through epicardial transmural catheters, excluding non-viable portions of the chamber. Patients were followed at 1, 3, 6 and 12 months postoperatively with echocardiograms. Data are presented for the first 11 patients for whom core lab echocardiographic data were available at 12 months of follow-up. RESULTS: LV end-systolic index (LVESVI), percent decreases from baseline at 6 and 12 months were 36.2 ± 18.3 (P < 0.001) and 39.6 ± 14.8 (P < 0.001). LV end-diastolic volume index (LVEDVI) percent decreases from baseline at 6 and 12 months were 28.6 ± 18.8 (P < 0.001) at 6 months and 32.2 ± 14.9 (P < 0.005) at 12 months. All comparisons were by one-tailed t-tests using paired data. CONCLUSIONS: These results demonstrate the persistence of volume reduction employing a technique designed to be used on beating hearts without ventriculotomy or cardiopulmonary bypass. The extent of volume reduction was consistent with results of conventional SVR in experienced centres. These early data validate the further development of technical iterations leading to a clinical study employing a closed chest endovascular platform.
    European journal of cardio-thoracic surgery: official journal of the European Association for Cardio-thoracic Surgery 06/2013; · 2.40 Impact Factor
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    ABSTRACT: OBJECTIVE: Simultaneous inhibition of the cardiac equilibrative-p-nitrobenzylthioinosine (NBMPR)-sensitive (es) type of the equilibrative nucleoside transport 1 (ENT1) nucleoside transporter, with NBMPR, and adenosine deaminase, with erythro-9-[2-hydroxy-3-nonyl]adenine (EHNA), prevents release of myocardial purines and attenuates myocardial stunning and fibrillation in canine models of warm ischemia and reperfusion. It is not known whether prolonged administration of hypothermic cardioplegia influences purine release and EHNA/NBMPR-mediated cardioprotection in acutely ischemic hearts. METHODS: Anesthetized dogs (n = 46), which underwent normothermic aortic crossclamping for 20 minutes on-pump, were divided to determine (1) purine release with induction of intermittent antegrade or continuous retrograde hypothermic cardioplegia and reperfusion, (2) the effects of postischemic treatment with 100 μM EHNA and 25 μM NBMPR on purine release and global functional recovery, and (3) whether a hot shot and reperfusion with EHNA/NBMPR inhibits purine release and attenuates ventricular dysfunction of ischemic hearts. Myocardial biopsies and coronary sinus effluents were obtained and analyzed using high-performance liquid chromatography. RESULTS: Warm ischemia depleted myocardial adenosine triphosphate and elevated purines (ie, inosine > adenosine) as markers of ischemia. Induction of intermittent antegrade or continuous retrograde hypothermic (4°C) cardioplegia releases purines until the heart becomes cold (<20°C). During reperfusion, the levels of hypoxanthine and xanthine (free radical substrates) were >90% of purines in coronary sinus effluent. Reperfusion with EHNA/NBMPR abolished ventricular dysfunction in acutely ischemic hearts with and without a hot shot and hypothermic cardioplegic arrest. CONCLUSIONS: Induction of hypothermic cardioplegia releases purines from ischemic hearts until they become cold, whereas reperfusion induces massive purine release and myocardial stunning. Inhibition of cardiac es-ENT1 nucleoside transporter abolishes postischemic reperfusion injury in warm and cold cardiac surgery.
    The Journal of thoracic and cardiovascular surgery 02/2013; · 3.41 Impact Factor
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    ABSTRACT: BACKGROUND: Few studies have examined differences in long-term mortality between coronary artery bypass graft surgery and stenting with drug-eluting stents (DES) for multivessel disease without left main coronary artery stenosis. This study compares the risks of long-term mortality between these 2 procedures during a follow-up of up to 5 years. METHODS: Patients who underwent isolated bypass surgery (n = 13,212) and stenting with DES (n = 20,161) between October 2003 and December 2005 in New York State were followed for their vital status through 2008. To control for treatment selection bias, bypass and stenting patients were matched on age, number of diseased coronary vessels, presence of proximal or nonproximal left anterior descending (LAD) artery disease, and propensity of undergoing bypass surgery. Five-year survival rates for the 2 procedures were compared and hazard ratios for death of bypass surgery compared with stenting were obtained. RESULTS: The respective 5-year survival rates in the 8,121 pairs of matched bypass and stenting patients were 80.4% and 73.6% (p < 0.001), and the risk of death after bypass surgery was 29% lower than for stenting (hazard ratio = 0.71, 95% confidence interval: 0.67 to 0.77, p < 0.001). Significantly lower risks of death for bypass surgery were observed in patients with LAD artery disease but not in patients without LAD artery disease. Significantly lower risks of death for bypass surgery were also found in all patient subgroups defined by the presence of selected baseline risk factors. CONCLUSIONS: Bypass surgery is associated with lower risk of death than stenting with DES for multivessel disease without left main stenosis.
    The Annals of thoracic surgery 02/2013; · 3.45 Impact Factor
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    ABSTRACT: BACKGROUND: Risk scores are simplified linear formulas for predicting mortality or other adverse outcomes at the bedside without personal digital assistants or calculators. Although risk scores are available for valve surgery, they do not predict short-term mortality (within 30 days of surgery) after hospital discharge. METHODS: New York's Cardiac Surgery Reporting System 2007 to 2009 data were matched to vital statistics data to identify valve surgery with and without concomitant coronary artery bypass graft (CABG) surgery deaths occurring in the index admission or within 30 days after the procedure in any location. Risk scores were created to easily predict these outcomes by modifying more complicated logistic regression models. RESULTS: There were 13,455 isolated valve surgery patients and 8,373 valve/CABG surgery patients in the study. The respective in-hospital/30-day mortality rates were 4.03% and 6.60%. There are 11 risk factors comprising the isolated valve surgery score, with risk factor scores ranging from 1 to 8, and the highest observed total score is 28. There are 14 risk factors comprising the valve/CABG surgery score, with risk factor scores ranging from 1 to 6, and the highest observed total score is 19. The scores accurately predicted mortality in 2007 to 2009 as well as in 2004 to 2006, and were strongly correlated with complications and length of stay. CONCLUSIONS: The risk scores that were developed provide quick and accurate estimates of patients' chances of short-term mortality after cardiac valve surgery.
    The Annals of thoracic surgery 01/2013; · 3.45 Impact Factor
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    ABSTRACT: BACKGROUND: Simplified risk scores for coronary artery bypass graft surgery are frequently in lieu of more complicated statistical models and are valuable for informed consent and choice of intervention. Previous risk scores have been based on in-hospital mortality, but a substantial number of patients die within 30 days of the procedure. These deaths should also be accounted for, so we have developed a risk score based on in-hospital and 30-day mortality. METHODS: New York's Cardiac Surgery Reporting System was used to develop an in-hospital and 30-day logistic regression model for patients undergoing coronary artery bypass graft surgery in 2009, and this model was converted into a simple linear risk score that provides estimated in-hospital and 30-day mortality rates for different values of the score. The accuracy of the risk score in predicting mortality was tested. This score was also validated by applying it to 2008 New York coronary artery bypass graft data. Subsequent analyses evaluated the ability of the risk score to predict complications and length of stay. RESULTS: The overall in-hospital and 30-day mortality rate for the 10,148 patients in the study was 1.79%. There are seven risk factors comprising the score, with risk factor scores ranging from 1 to 5, and the highest possible total score is 23. The score accurately predicted mortality in 2009 as well as in 2008, and was strongly correlated with complications and length of stay. CONCLUSIONS: The risk score is a simple way of estimating short-term mortality that accurately predicts mortality in the year the model was developed as well as in the previous year. Perioperative complications and length of stay are also well predicted by the risk score.
    The Annals of thoracic surgery 11/2012; · 3.45 Impact Factor
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    ABSTRACT: Ischemia/reperfusion injury remains an important cause of morbidity and mortality after coronary artery bypass graft (CABG) surgery. In a meta-analysis of randomized controlled trials, perioperative and postoperative infusion of acadesine, a first-in-class adenosine-regulating agent, was associated with a reduction in early cardiac death, myocardial infarction, and combined adverse cardiac outcomes in participants undergoing on-pump CABG surgery. To assess the efficacy and safety of acadesine administered in the perioperative period in reducing all-cause mortality, nonfatal stroke, and severe left ventricular dysfunction (SLVD) through 28 days. The Reduction in Cardiovascular Events by Acadesine in Patients Undergoing CABG (RED-CABG) trial, a randomized, double-blind, placebo-controlled, parallel-group evaluation of intermediate- to high-risk patients (median age, 66 years) undergoing nonemergency, on-pump CABG surgery at 300 sites in 7 countries. Enrollment occurred from May 6, 2009, to July 30, 2010. Eligible participants were randomized 1:1 to receive acadesine (0.1 mg/kg per minute for 7 hours) or placebo (both also added to cardioplegic solutions) beginning just before anesthesia induction. Composite of all-cause mortality, nonfatal stroke, or need for mechanical support for SLVD during and following CABG surgery through postoperative day 28. Because results of a prespecified futility analysis indicated a very low likelihood of a statistically significant efficacious outcome, the trial was stopped after 3080 of the originally projected 7500 study participants were randomized. The primary outcome occurred in 75 of 1493 participants (5.0%) in the placebo group and 76 of 1493 (5.1%) in the acadesine group (odds ratio, 1.01 [95% CI, 0.73-1.41]). There were no differences in key secondary end points measured. In this population of intermediate- to high-risk patients undergoing CABG surgery, acadesine did not reduce the composite of all-cause mortality, nonfatal stroke, or SLVD. clinicaltrials.gov Identifier: NCT00872001.
    JAMA The Journal of the American Medical Association 07/2012; 308(2):157-64. · 29.98 Impact Factor
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    ABSTRACT: No simplified bedside risk scores have been created to predict long-term mortality after coronary artery bypass graft surgery. The New York State Cardiac Surgery Reporting System was used to identify 8597 patients who underwent isolated coronary artery bypass graft surgery in July through December 2000. The National Death Index was used to ascertain patients' vital statuses through December 31, 2007. A Cox proportional hazards model was fit to predict death after CABG surgery using preprocedural risk factors. Then, points were assigned to significant predictors of death on the basis of the values of their regression coefficients. For each possible point total, the predicted risks of death at years 1, 3, 5, and 7 were calculated. It was found that the 7-year mortality rate was 24.2 in the study population. Significant predictors of death included age, body mass index, ejection fraction, unstable hemodynamic state or shock, left main coronary artery disease, cerebrovascular disease, peripheral arterial disease, congestive heart failure, malignant ventricular arrhythmia, chronic obstructive pulmonary disease, diabetes mellitus, renal failure, and history of open heart surgery. The points assigned to these risk factors ranged from 1 to 7; possible point totals for each patient ranged from 0 to 28. The observed and predicted risks of death at years 1, 3, 5, and 7 across patient groups stratified by point totals were highly correlated. The simplified risk score accurately predicted the risk of mortality after coronary artery bypass graft surgery and can be used for informed consent and as an aid in determining treatment choice.
    Circulation 04/2012; 125(20):2423-30. · 14.95 Impact Factor
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    ABSTRACT: To determine the role of the p-nitrobenzylthioinosine-sensitive equilibrative nucleoside transporter 1 (es-ENT1) in postmyocardial infarction reperfusion injury-mediated ventricular fibrillation and regional dysfunction. We used erythro-9 (2-hydroxy-3-nonyl)-adenine and p-nitrobenzylthioinosine to inhibit both adenosine deamination and transport in a canine model of off pump acute myocardial infarction. Anesthetized adult dogs (n = 37), instrumented to monitor the percentage of systolic segmental shortening and wall thickening using sonomicrometry, underwent 90 minutes of left anterior descending coronary artery occlusion and 120 minutes of reperfusion. Myocardial coronary blood flow, adenosine triphosphate pool, infarct size, and the incident of ventricular fibrillation and cardioversion were also measured. The dogs received an intravenous infusion of the vehicle (control) or 100 μM of erythro-9 (2-hydroxy-3-nonyl)-adenine and 25 μM p-nitrobenzylthioinosine before ischemia (preconditioning group) or just before reperfusion (postconditioning group). In the control group, adenosine triphosphate depletion was associated with the accumulation of more inosine than adenosine during ischemia and washed out during reperfusion. Myocardial adenosine and inosine were the major nucleosides in the pre- and postconditioning groups during ischemia and remained detectable during reperfusion. In both groups, recovery of systolic segmental shortening and wall thickening and a reduction in the incidence of ventricular fibrillation (P < .05 vs the control group) coincided with retention of myocardial nucleosides. The infarct size in the 3 groups was not significantly different, independent of myocardial blood flow during ischemia. Preconditioning or postconditioning with erythro-9 (2-hydroxy-3-nonyl)-adenine/p-nitrobenzylthioinosine significantly reduced the incidence of ventricular fibrillation and cardioversion and attenuated regional contractile dysfunction mediated by postmyocardial infarction reperfusion injury. It is concluded that p-nitrobenzylthioinosine-sensitive equilibrative nucleoside transporter 1 played a major role in these events.
    The Journal of thoracic and cardiovascular surgery 02/2012; 144(1):250-5. · 3.41 Impact Factor
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    ABSTRACT: The inhibition of adenosine deaminase with erythro-9 (2-hydroxy-3-nonyl)-adenine (EHNA) and the es-ENT1 transporter with p-nitro-benzylthioinosine (NBMPR), entraps myocardial intracellular adenosine during on-pump warm aortic crossclamping, leading to a complete recovery of cardiac function and adenosine triphosphate (ATP) during reperfusion. The differential role of entrapped intracellular and circulating adenosine in EHNA/NBMPR-mediated protection is unknown. Selective (8-cyclopentyl-1,3-dipropyl-xanthine) or nonselective [8-(p-sulfophenyl)theophyline] A1 receptor antagonists were used to block adenosine A1-receptor contribution in EHNA/NBMPR-mediated cardiac recovery. Anesthetized dogs (n = 45), instrumented to measure heart performance using sonomicrometry, were subjected to 30 minutes of warm aortic crossclamping and 60 minutes of reperfusion. Three boluses of the vehicle (series A) or 100 μM EHNA and 25 μM NBMPR (series B) were infused into the pump at baseline, before ischemia and before reperfusion. 8-Cyclopentyl-1,3-dipropyl-xanthine (10 μM) or 8-(p-sulfophenyl)theophyline (100 μM) was intra-aortically infused immediately after aortic crossclamping distal to the clamp in series A and series B. The ATP pool and nicotinamide adenine dinucleotide was determined using high-performance liquid chromatography. Ischemia depleted ATP in all groups by 50%. The adenosine/inosine ratios were more than 10-fold greater in series B than in series A (P < .001). ATP and function recovered in the EHNA/NBMPR-treated group (P < .05 vs control group). 8-Cyclopentyl-1,3-dipropyl-xanthine and 8-(p-sulfophenyl)theophyline partially reduced cardiac function in series A and B to the same degree but did not abolish the EHNA/NBMPR-mediated protection in series B. In addition to the cardioprotection mediated by activation of the adenosine receptors by extracellular adenosine, EHNA/NBMPR entrapment of intracellular adenosine provided a significant component of myocardial protection despite adenosine A1 receptor blockade.
    The Journal of thoracic and cardiovascular surgery 02/2012; 144(1):243-9. · 3.41 Impact Factor
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    ABSTRACT: The survival difference between off-pump and on-pump coronary artery bypass graft surgery for follow-up longer than 5 years is not well-understood. The objective of this study is to examine the difference in 7-year mortality after these 2 procedures. The state of New York's Cardiac Surgery Reporting System was used to identify the 2640 off-pump and 5940 on-pump patients discharged from July through December 2000. The National Death Index was used to ascertain patients' vital statuses through 2007. A logistic regression model was fit to predict the probability of receiving an off-pump procedure using baseline patient characteristics. Off-pump and on-pump patients were matched with a 1:1 ratio based on the probability of receiving an off-pump procedure. Kaplan-Meier survival curves for the 2 procedures were compared using the propensity-matched data, and the hazard ratio for death for off-pump in comparison with on-pump procedures was obtained. In subgroup analyses, the significance of interactions between type of surgery and baseline risk factors was tested. In this study, 2631 pairs of off-pump and on-pump patients were propensity matched. The 7-year Kaplan-Meier survival rates were 71.2% and 73.4% (P=0.07) for off-pump and on-pump surgery, respectively. The hazard ratio for death (off-pump versus on-pump) was 1.10 (95% confidence interval: 0.99 to 1.21, P=0.07). No statistical significance was detected for the interaction terms between the type of surgery and a number of different baseline risk factors. The difference in long-term mortality between on-pump and off-pump coronary artery bypass graft surgery is not statistically significant.
    Circulation Cardiovascular Quality and Outcomes 01/2012; 5(1):76-84. · 5.04 Impact Factor
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    ABSTRACT: The elastic modulus of bioengineered materials has a strong influence on the phenotype of many cells including cardiomyocytes. On polyacrylamide (PAA) gels that are laminated with ligands for integrins, cardiac myocytes develop well organized sarcomeres only when cultured on substrates with elastic moduli in the range 10 kPa-30 kPa, near those of the healthy tissue. On stiffer substrates (>60 kPa) approximating the damaged heart, myocytes form stress fiber-like filament bundles but lack organized sarcomeres or an elongated shape. On soft (<1 kPa) PAA gels myocytes exhibit disorganized actin networks and sarcomeres. However, when the polyacrylamide matrix is replaced by hyaluronic acid (HA) as the gel network to which integrin ligands are attached, robust development of functional neonatal rat ventricular myocytes occurs on gels with elastic moduli of 200 Pa, a stiffness far below that of the neonatal heart and on which myocytes would be amorphous and dysfunctional when cultured on polyacrylamide-based gels. The HA matrix by itself is not adhesive for myocytes, and the myocyte phenotype depends on the type of integrin ligand that is incorporated within the HA gel, with fibronectin, gelatin, or fibrinogen being more effective than collagen I. These results show that HA alters the integrin-dependent stiffness response of cells in vitro and suggests that expression of HA within the extracellular matrix (ECM) in vivo might similarly alter the response of cells that bind the ECM through integrins. The integration of HA with integrin-specific ECM signaling proteins provides a rationale for engineering a new class of soft hybrid hydrogels that can be used in therapeutic strategies to reverse the remodeling of the injured myocardium.
    Journal of biomechanics 12/2011; 45(5):824-31. · 2.66 Impact Factor
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    ABSTRACT: There is little information on relative survival with follow-up longer than 5 years in patients undergoing coronary artery bypass grafting (CABG) and patients undergoing percutaneous coronary intervention (PCI) with stenting. This study tested the hypothesis that CABG is associated with a lower risk of long-term (8-year) mortality than is stenting with bare-metal stents for multivessel coronary disease. We identified 18,359 patients with multivessel disease who underwent isolated CABG and 13,377 patients who received bare-metal stenting in 1999 to 2000 in New York and followed their vital status through 2007 using the National Death Index (NDI). We matched CABG and stent patients on the number of diseased coronary vessels, proximal left anterior descending (LAD) artery disease, and propensity of undergoing CABG based on numerous patient characteristics and compared survival after the 2 procedures. In the 7,235 pairs of matched patients, the overall 8-year survival rates were 78.0% for CABG and 71.2% for stenting (hazard ratio [HR], 0.68; 95% confidence interval [CI], 0.64 to 0.74; p < 0.001). For anatomic groups classified by the number of diseased vessels and proximal LAD involvement, the HRs ranged from 0.53 (p < 0.001) for patients with 3-vessel disease involving proximal LAD artery disease to 0.78 (p = 0.05) for patients with 2-vessel disease but no disease in the LAD artery. A lower risk of death after CABG was observed in all subgroups stratified by a number of baseline risk factors. Coronary artery bypass grafting is associated with a lower risk of death than is stenting with bare metal stents for multivessel coronary disease.
    The Annals of thoracic surgery 12/2011; 92(6):2132-8. · 3.45 Impact Factor
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    ABSTRACT: The aim of this study was to identify reasons for and predictors of readmission. Short-term readmissions have been identified as an important cause of escalating health care costs, and coronary artery bypass graft (CABG) surgery is 1 of the most expensive procedures. We retrospectively analyzed 30-day readmissions for 33,936 New York State patients who underwent CABG surgery between January 1, 2005, and November 30, 2007. The main reasons for readmission (principal diagnoses) and the significant independent predictors of readmission were identified. The hospital-level relationship between risk-adjusted mortality rate and risk-adjusted readmission rate was explored to determine the value of readmission rate as a complementary measure of quality. The most common reasons for readmission were post-operative infection (16.9%), heart failure (12.8%), and "other complications of surgical and medical care" (9.8%). Increasing age, female sex, African-American race, higher body mass index, numerous comorbidities, 2 post-operative complications (renal failure and unplanned cardiac reoperation), Medicare or Medicaid status, discharges to a skilled nursing facility, saphenous vein grafts, and longer lengths of stay were all associated with higher rates of readmission. The correlation between the risk-adjusted 30-day readmission rate of hospitals and risk-adjusted in-hospital/30-day mortality rate was 0.32 (p = 0.047). The range across hospitals in the readmission rate was from 8.3% to 21.1%. The 30-day readmission rate for CABG surgery remains high, despite decreases in short-term mortality. Patients with any of the numerous risk factors for readmission should be closely monitored. Hospital readmission rates are not highly correlated with mortality rates and might serve as an independent quality measure.
    JACC. Cardiovascular Interventions 05/2011; 4(5):569-76. · 1.07 Impact Factor
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    ABSTRACT: The objective of the present study was to determine if a new procoagulant molecule, carbon monoxide releasing molecule (tricarbonyldichlororuthenium (II) dimer; CORM-2) would improve coagulation following cardiopulmonary bypass (CPB). Plasma was obtained from patients undergoing elective cardiac surgery requiring CPB. Whole blood was collected and anticoagulated with sodium citrate after induction of anesthesia and again after CPB and heparin neutralization with protamine. Blood samples were centrifuged for 15 min, with plasma collected and stored at -80°C prior to analysis. Samples were subsequently exposed to 0 or 100 μmol/l CORM-2, with coagulation activated with tissue factor. Data were collected with thrombelastography until clot strength stabilized. Patients underwent CPB for 133 ± 61 min (mean ± SD). The velocity of thrombus formation was significantly decreased (52%) by CPB, as was clot strength (53%). Addition of CORM-2 to plasma samples obtained after CPB significantly increased the velocity of clot formation (75%) and strength (52%) compared to matched unexposed samples. The lesion of plasmatic coagulation associated with CPB was significantly improved in vitro by addition of CORM-2. If preclinical assessments of efficacy and safety of CORM-2 are favorable, future clinical trials involving CORM-2 or other CORMs as a hemostatic intervention in the setting of CPB are justified.
    Blood coagulation & fibrinolysis: an international journal in haemostasis and thrombosis 02/2011; 22(5):362-8. · 1.25 Impact Factor
  • Michael Green, Jay Parekh, Amardeep Heyer, Andrew S Wechsler
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    ABSTRACT: Ventricular fibrillation is a common arrhythmia encountered after the termination of cardiopulmonary bypass. Risk is augmented in patients who are undergoing repeat cardiac procedures with most documented complications occurring during repeat sternotomy. Aortic valve surgery is more complex after coronary artery bypass grafting using internal mammary arteries, and it compounds the increased risk of repeat sternotomy. This case report describes a low-flow state artificially created by sternal retraction applying tension on a right internal mammary artery to posterior descending artery anastomosis, with resultant unrecognized myocardial ischemia yielding refractory ventricular fibrillation during aortic valve replacement.
    The Annals of thoracic surgery 11/2010; 90(5):1698-9. · 3.45 Impact Factor
  • European Journal of Heart Failure 10/2010; 12(10):1024-7. · 6.58 Impact Factor

Publication Stats

3k Citations
1,323.82 Total Impact Points

Institutions

  • 2003–2014
    • Drexel University College of Medicine
      • • Department of Cardiothoracic Surgery
      • • Department of Anesthesiology
      Philadelphia, Pennsylvania, United States
  • 2013
    • University at Albany, The State University of New York
      • Department of Health Policy, Management, and Behavior
      New York City, New York, United States
  • 2004–2013
    • Drexel University
      • Department of Cardiothoracic Surgery
      Philadelphia, Pennsylvania, United States
    • Lankenau Institute for Medical Research
      Wynnewood, Oklahoma, United States
  • 1991–2013
    • Virginia Commonwealth University
      • • Division of Cardiothoracic Surgery
      • • Department of Surgery
      Ричмонд, Virginia, United States
  • 2011–2012
    • Penn State Hershey Medical Center and Penn State College of Medicine
      • Public Health Sciences
      Hershey, Pennsylvania, United States
  • 2010–2012
    • Albany State University
      Олбани, Georgia, United States
  • 1999–2003
    • University of Louisville
      • Department of Surgery
      Louisville, KY, United States
  • 2000
    • University of Pennsylvania
      • Division of Cardiothoracic Surgery
      Philadelphia, PA, United States
  • 1998
    • University of the Sciences in Philadelphia
      Philadelphia, Pennsylvania, United States
  • 1990
    • Richmond VA Medical Center
      Ричмонд, Virginia, United States
  • 1989
    • SickKids
      Toronto, Ontario, Canada
  • 1977–1989
    • Duke University Medical Center
      • Department of Surgery
      Durham, NC, United States
  • 1981–1988
    • Duke University
      • Department of Surgery
      Durham, North Carolina, United States
  • 1987
    • University of Massachusetts Medical School
      • Department of Surgery
      Worcester, MA, United States