Daniel Marelli

University of California, Los Angeles, Los Angeles, California, United States

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Publications (70)341.44 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Mechanical circulatory support is a highly effective technology to maintain organ perfusion in patients with cardiogenic shock as a bridge to transplantation. Although implantation of a left ventricular assist device alone is often the preferred configuration, patients with biventricular failure and significant end-organ dysfunction often require biventricular assistance. Between January 2000 and September 2008, 80 patients with severe biventricular failure were accepted for heart transplantation and received a pneumatic biventricular assist devices as a bridge to transplant. Patients were retrospectively divided into 2 groups: those successfully bridged to transplant (Group A) and those who died (Group B). Patients were also divided into 2 periods of implantation: Group X (2000-2005) and Group Y (2006-2008, which used a multidiscipline selection process). Overall success rate to transplantation was 71.3%, with Group Y demonstrating an 82% success to transplant rate vs 63% in Group X. One-year actuarial survival after transplant was 89% compared with 92% in patients without a ventricular assist device. There were no statistically significant laboratory parameters between Groups A and B identifying potential risk factors for poor outcome. Biventricular assist device therapy represents an effective and reliable means of supporting selected Interagency Registry for Mechanically Assisted Circulatory Support profile 1 patients as a bridge to transplantation, with excellent success to transplant rates and post-transplant survival.
    The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 06/2011; 30(10):1143-7. DOI:10.1016/j.healun.2011.04.005 · 5.61 Impact Factor
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    ABSTRACT: Inhaled nitric oxide has been shown to reduce pulmonary vascular resistance in patients undergoing cardiothoracic surgery, but it is limited by toxicity, the need for special monitoring, and cost. Inhaled prostacyclin also decreases pulmonary artery pressure, is relatively free of toxicity, requires no specific monitoring, and is less expensive. The objective of this study was to compare nitric oxide and prostacyclin in the treatment of pulmonary hypertension, refractory hypoxemia, and right ventricular dysfunction in thoracic transplant recipients in a prospective, randomized, crossover pilot trial. Heart transplant and lung transplant recipients were randomized to nitric oxide or prostacyclin as initial treatment, followed by a crossover to the other agent after 6 hours. Pulmonary vasodilators were initiated in the operating room for pulmonary hypertension, refractory hypoxemia, or right ventricular dysfunction. Nitric oxide was administered at 20 ppm, and prostacyclin was administered at 20,000 ng/mL. Hemodynamic and oxygenation parameters were recorded before and after initiation of pulmonary vasodilator therapy. At 6 hours, the hemodynamic and oxygenation parameters were recorded again, just before discontinuing the initial agent. Crossover baseline parameters were measured 30 minutes after the initial agent had been stopped. The crossover agent was then started, and the hemodynamic and oxygenation parameters were measured again 30 minutes later. Heart transplant and lung transplant recipients (n = 25) were randomized by initial treatment (nitric oxide, n = 14; prostacyclin, n = 11). Nitric oxide and prostacyclin both reduced pulmonary artery pressure and central venous pressure, and improved cardiac index and mixed venous oxygen saturation on initiation of therapy. More importantly, at the 6-hour crossover trial, there were no significant differences between nitric oxide and prostacyclin in the reduction of pulmonary artery pressures or central venous pressure, or in improvement in cardiac index or mixed venous oxygen saturation. Nitric oxide and prostacyclin did not affect the oxygenation index or systemic blood pressure. There were no complications associated with nitric oxide or prostacyclin. In heart transplant and lung transplant recipients, nitric oxide and prostacyclin similarly reduce pulmonary artery pressures and central venous pressure, and improve cardiac index and mixed venous oxygen saturation. Inhaled prostacyclin may offer an alternative to nitric oxide in the treatment of pulmonary hypertension in thoracic transplantation.
    The Journal of thoracic and cardiovascular surgery 12/2009; 138(6):1417-24. DOI:10.1016/j.jtcvs.2009.04.063 · 3.99 Impact Factor
  • The Journal of thoracic and cardiovascular surgery 07/2009; 137(6):1557-9. DOI:10.1016/j.jtcvs.2008.09.012 · 3.99 Impact Factor
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    ABSTRACT: The reluctance to use organs from donors who have died from severe infections is based on the potential transmission of an infectious agent to the recipient and on the uncertainty about allograft function in the setting of severe donor sepsis. From 1999 to 2007, donor hospital records were reviewed which focused on microbiology cultures and sensitivity results; type and duration of antimicrobial therapy; hemodynamic data, results of echocardiogram, and imaging studies. Preliminary positive and negative results from pre-harvest blood, respiratory, urine, and cerebrospinal fluid cultures were verified with the procurement agency. The harvesting surgeon performed gross inspection of donor valvular structures. Nine donor hearts were transplanted from patients who expired from community onset infections with severe septic shock, meningitis, and/or pneumonia caused by Streptococcus pneumoniae (n = 4), Streptococcus milleri (n = 2), Neisseria meningitidis (n = 2), and unidentified gram- positive cocci (n = 1). Four donors had probable infection-induced intracranial hemorrhage, and all donors were vasopressor-dependent before organ procurement. No evidence of donor-transmitted infection, sepsis, or rejection was observed, and long-term function remained excellent; allograft dysfunction in three patients resolved after transplant. Our series of nine donors represents approximately 1.3% of successfully transplanted cardiac allografts during the respective period of review. Patients succumbing to severe infections (meningitis, pneumonia, and septic shock) should not be arbitrarily excluded for possible heart donation. Assessing the suitability of donors with severe infections requires flawless communication between the donor and transplant facility, including a comprehensive evaluation of donor infection and pathogen(s), severity of sepsis, adequacy of antimicrobial treatment, and the degree of sepsis-induced myocardial dysfunction.
    The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 04/2009; 28(3):260-5. DOI:10.1016/j.healun.2008.11.911 · 5.61 Impact Factor
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    ABSTRACT: We sought to compare outcomes in patients > or = 60 years of age with those of their younger counterparts who underwent ventricular assist device implantation intended as a bridge to cardiac transplantation and also to identify retrospectively additional pre- and postoperative factors that might portend adverse outcomes.The medical records of 88 patients who were treated with bridge-to-transplantation ventricular assist devices from 1996 through 2007 were reviewed. Laboratory values, hemodynamic parameters, and the need for hemodynamic support were evaluated. Postoperative complications and bridge-to-transplantation success rates versus death rates were evaluated. Seventeen patients were > or = 60 years old and 71 patients were < 60 years old. In the older group, 59% of patients underwent successful bridging to transplantation, compared with 69% of the younger patients (P = 0.41). Multivariate analysis distinguished age > or = 60, female sex, earlier time period of operation, higher mean pulmonary arterial and central venous pressures, need for preoperative intra-aortic balloon pumps, and postoperative respiratory failure as independent risk factors for death. After orthotopic heart transplantation, survival to hospital discharge was 100% in the older group and 93.9% in the younger patients. Median lengths of stay were similar in both age categories.Multivariate analysis identified age as 1 of 6 independent risk factors for death in this study. Patients who successfully underwent cardiac transplantation, however, had similar survival statistics regardless of age category. Case-by-case evaluation is warranted when analyzing risk-benefit ratios of bridge-to-transplantation ventricular assist device therapy in the older patient population.
    Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 02/2009; 36(3):214-9. · 0.63 Impact Factor
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    ABSTRACT: Heart transplantation in the elderly is increasingly common. In the mid-1990s, 25% of recipients in our program were >62 years of age. We evaluated outcomes from one institution with the hypothesis that older recipients may be at higher risk of major complications associated with immunosuppression. We analyzed results for 182 patients aged 62 to 75 years (mean +/- SD: 66.3 +/- 11.4 years) who underwent heart transplantation between January 1995 and July 2001 at a single institution. They were compared with a control group of 348 contemporaneous adult recipients aged 18 to 62 years (mean +/- SD: 48.2 +/- 11.4 years). All recipients in this consecutive cohort had a follow-up of at least at least 5 years. End-points studied were Kaplan-Meier survival, freedom from dialysis and freedom from malignancy at 100 months. Follow-up was 100% at 100 months. At 100 months, survival for the elderly was 55% (46 remaining at risk) and 63% (102 remaining at risk) for controls (p = 0.051, log-rank test). Re-transplant and dialysis, but not recipient age or malignancy, were predictive of survival by regression analysis (p = 0.003, p < 0.001, p = 0.53 and p = 0.84, respectively). Freedom from malignancy at 100 months was 68% for the elderly and 95% for controls (p < 0.001). Age predicted malignancy by regression analysis (p < 0.001). At 100 months, freedom from dialysis was 81% for the elderly and 87% for controls (p = 0.005). Pre-operative creatinine, but not age, was predictive of need for dialysis (p = 0.003 and p = 0.47, respectively). Although long-term survival of older heart transplant recipients is acceptable, it is significantly lower than in young recipients. The increased risk of renal failure and malignancy among elderly patients likely influences the difference in survival observed between the two groups. Pre-operative renal function warrants careful consideration. As ventricular assist device technology improves, it may be used to complement heart transplantation to avoid immunosuppression and its side effect of malignancy in older patients with advanced heart failure.
    The Journal of heart and lung transplantation: the official publication of the International Society for Heart Transplantation 08/2008; 27(8):830-4. DOI:10.1016/j.healun.2008.05.006 · 5.61 Impact Factor
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    ABSTRACT: Atherosclerosis is an example of an inflammatory disorder. During the acute phase and under inflammatory conditions, high-density lipoprotein (HDL), which is normally anti-inflammatory, can become proinflammatory. Reactive oxygen species generated by several enzyme systems can modify phospholipids and sterols, producing oxidized phospholipids and oxidized sterols that reduce the capacity of HDL to protect against undesirable oxidative modifications of molecules. In animal models of dyslipidemia, diabetes, vascular inflammation, and chronic rejection, it is observed that reducing oxidative and inflammatory pressure will help HDL regain its protective role. One way to accomplish this is through the use of apolipoprotein A-I mimetic peptides, which remove oxidation products from lipoproteins and cell membranes, returning normal structure and function to low-density lipoprotein and HDL. These mimetic peptides markedly reduce atherosclerosis in animal models. Published studies of apolipoprotein mimetic peptides in models of inflammatory disorders other than atherosclerosis suggest that they have efficacy in a wide range of inflammatory conditions.
    Current Atherosclerosis Reports 05/2008; 10(2):171-6. DOI:10.1007/s11883-008-0025-z · 3.06 Impact Factor
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    ABSTRACT: The use of autologous pericardium for annuloplasty during mitral valve repair is a subject of controversy; hence, the study aim was to evaluate the authors' long-term results using this technique. A retrospective review was conducted of 173 consecutive patients (mean age 59.6 +/- 16.3 years; range: 19-92 years) who underwent mitral valve repair complemented by annuloplasty between January 1998 and December 2003. The major causes of mitral regurgitation (MR) were annular dilatation and prolapse of the posterior leaflet. Annuloplasty was performed in all patients using a strip of pericardium treated with 0.6% glutaraldehyde for 10 min. Two rows of continuous horizontal mattress Gore-Tex sutures were used to secure the pericardium to the mitral annulus. Follow up continued for a mean period of 5.25 +/- 1.62 years (range: 1.97 to 9.43 years), and was complete. Three patients (1.7%) died within 30 days of surgery. Subsequently, five patients (2.9%) with MR (with or without mitral stenosis) underwent reoperation at a mean of 3.0 +/- 2.7 years after the initial surgery. At seven years after surgery the actuarial survival rate was 92.5%, and freedom from reoperation 97.1%. Follow up echocardiography was performed in 160 patients. Among these patients, no MR was detected in 34 (21.2%), while 88 (55%) had grade 1 MR, 35 (21.8%) grade 2, and three (1.8%) had grade 3. None of the patients had grade 4 MR. The study results indicated that autologous pericardium mitral annuloplasty of the mitral valve provides effective, durable and reproducible repair, and avoids the use of foreign materials.
    The Journal of heart valve disease 02/2008; 17(1):10-5. · 0.73 Impact Factor
  • The Journal of Heart and Lung Transplantation 02/2008; 27(2). DOI:10.1016/j.healun.2007.11.256 · 5.61 Impact Factor
  • The Journal of Heart and Lung Transplantation 02/2008; 27(2). DOI:10.1016/j.healun.2007.11.276 · 5.61 Impact Factor
  • The Journal of Heart and Lung Transplantation 02/2008; 27(2). DOI:10.1016/j.healun.2007.11.297 · 5.61 Impact Factor
  • The Journal of Heart and Lung Transplantation 02/2008; 27(2):S120. DOI:10.1016/j.healun.2007.11.174 · 5.61 Impact Factor
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    ABSTRACT: Uncorrected functional tricuspid regurgitation can lead to long-term morbidity and mortality. To evaluate our results using autologous pericardium annuloplasty to treat tricuspid regurgitation, we retrospectively reviewed 59 consecutive adult patients aged 19 years to 83 years (58.7 +/- 15.5 years) who underwent tricuspid valve annuloplasty between 2000 and 2003. Concomitant procedures consisted of mitral valve surgery in 83% of patients, aortic valve surgery in 28%, coronary bypass in 31%, and atrial-septal defect correction in 28%. Annuloplasty was performed using a strip of pericardium treated in glutaraldehyde 0.6% for 10 min. Two rows of continuous horizontal mattress Gore-Tex sutures were used to secure the pericardium to the tricuspid annulus. Follow-up was performed in 100% of the patients, and the mean follow-up was 4.4 +/- 1.2 years (range, 2.4 to 7 years). Postoperative death within 30 days occurred in 1 of 59 patients (1.6%). None of the patients required reoperation related to tricuspid regurgitation or stenosis. The actuarial survival rate was 98.4% at 7 years after operation. Echocardiography was performed in 58 of 58 surviving patients (100%). Up to 7 years postoperatively, tricuspid regurgitation was trace in 67.2% of patients, mild in 31%, and moderate in 1.8%; there was no occurrence of severe regurgitation on follow-up. Our results indicate that autologous pericardium tricuspid annuloplasty is a useful procedure in patients with moderate or severe tricuspid regurgitation. This procedure provides a durable, reproducible annuloplasty of the tricuspid valve.
    Heart Surgery Forum 02/2008; 11(1):E4-8. DOI:10.1532/HSF98.20071124
  • The Journal of Heart and Lung Transplantation 02/2008; 27(2). DOI:10.1016/j.healun.2007.11.213 · 5.61 Impact Factor
  • The Journal of Heart and Lung Transplantation 02/2008; 27(2). DOI:10.1016/j.healun.2007.11.342 · 5.61 Impact Factor
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    ABSTRACT: The ability of high-density lipoprotein (HDL) to promote cholesterol efflux is an important component of its ability to protect against cardiovascular disease. In addition, the anti-inflammatory properties of HDL are important as well. As part of the innate immune system, HDL appears to have evolved to increase inflammation in the presence of an acute phase response but to inhibit inflammation in the absence of an acute phase response. In a study of humans with coronary heart disease, it was found that the patients who had proinflammatory HDL prior to statin therapy (and half of them despite a profound decrease in plasma lipids following statin therapy) continued to have proinflammatory HDL. Anti-inflammatory HDL was effective in promoting cholesterol efflux whereas proinflammatory HDL was relatively weak in its ability to promote cholesterol efflux. Oxidative alterations of the main protein of HDL, apolipoprotein A-I, impaired its capacity to promote cholesterol efflux from monocyte macrophages. Therefore, HDL composition, structure, and function appear to be more crucial than HDL cholesterol concentrations in determining risk for cardiovascular disorders.
    Current Atherosclerosis Reports 10/2007; 9(3):244-8. DOI:10.1007/s11883-007-0026-3 · 3.06 Impact Factor
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    Daniel Marelli · Richard J Shemin
    Circulation 09/2007; 116(6):586-7. DOI:10.1161/CIRCULATIONAHA.107.716670 · 14.95 Impact Factor
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    ABSTRACT: Postoperative tricuspid valve regurgitation is moderate to severe in 15% to 20% of heart transplant recipients despite use of the bicaval surgical technique. We hypothesized that the regurgitation might be partly due to increased tension on the donor right atrium. To study the right atrial distortion, we modified the standard bicaval anastomosis. Our technique involves augmenting the donor right atrial anterior wall with a flap of the recipient's right atrium, which is left attached in continuity with the anterior aspect of the inferior vena cava along 65% of its circumference. We measured tricuspid regurgitation, right atrial area, and right atrioventricular diameter in 7 consecutive patients who underwent orthotopic heart transplantation with the modified anastomosis. Tricuspid regurgitation was graded as follows: 1 = trace, <10%; 2 = mild, 10%-24%; 3 = moderate, 25%-50%; and 4 = severe, >50%. All patients were weaned from inotropic support within 1 week after transplantation with excellent ventricular function, no heart block, and 100% survival at 30 days. The median follow-up time was 173 days (44-358 days). Other median measurements included tricuspid valve regurgitation jet area, 0.30 cm(2) (0-1.90 cm(2)); right atrial area, 15.90 cm(2) (14.47-18.00 cm(2)); atrioventricular diameter, 2.70 cm (2.63-3.09 cm); and tricuspid regurgitation, 1.67% (0-12.42%). Mild regurgitation occurred in 1 recipient; in all others, it was trace. The modified inferior vena caval anastomosis is simple and safe. It eliminates moderate and severe tricuspid valve regurgitation without routine annuloplasty after orthotopic heart transplantation via the bicaval technique.
    Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital 02/2007; 34(1):30-5. · 0.63 Impact Factor
  • Journal of Thoracic and Cardiovascular Surgery 09/2005; 130(2):599-601. DOI:10.1016/j.jtcvs.2005.02.009 · 3.99 Impact Factor
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    ABSTRACT: Expansion of potential donor pool may be facilitated by using cardiac allografts with long ischemic time. Early graft failure and potential relation to transplant coronary artery disease remains a concern. We sought to evaluate outcomes of heart transplantation in recipients of donor allografts with prolonged ischemia time. The study group consisted of 46 (mean age, 52 years) consecutive patients at UCLA from 1994 to 2002 that underwent heart transplantation with ischemia time > 300 min. This group was compared to a case-matched control group of 46 (mean age, 51 years) patients identified from our database during this time frame for the following factors: UNOS status, congenital heart disease diagnosis, preop inotropes, pretransplantation creatinine > 1.5 and recipient age. Primary endpoint was mortality and secondary were rejection rate and transplant coronary artery disease. Allografts were perfused and stored in cold University of Wisconsin solution. Mean donor ages of the study and case-matched control group were 34+/-15 and 34+/-14 years, respectively. Mean ischemia times were 388 (range, 301-600 min) and 173 (range, 96-236 min), respectively. The death incidence rate per 100 transplants per year was 9% for the study group and 7.4% for the matched group (P = 0.50). Thirty-day mortality for the study and case-matched groups were 4.3 and 2.1%, respectively (P = 0.9). Late mortality was 16.5 and 18.5%, respectively (P = 0.9). The risk of death after 30 days was 7.5 and 5.8%, respectively (P = 0.5, log-rank). One-year incidence of acute cellular rejection in the study and case-matched groups were 2 and 4.5% (P = 0.36), respectively. One-year incidence of transplant coronary artery disease in the study and case-matched groups were 4.3 and 5.4%, respectively (P = 0.68). Donor hearts with ischemia time greater than 300 min provide comparable early and intermediate outcomes given judicious and careful donor and recipient matching and our current techniques of myocardial preservation and modified reperfusion.
    European Journal of Cardio-Thoracic Surgery 07/2005; 28(1):143-8. DOI:10.1016/j.ejcts.2005.01.067 · 2.81 Impact Factor

Publication Stats

1k Citations
341.44 Total Impact Points

Institutions

  • 1999–2011
    • University of California, Los Angeles
      • • Department of Surgery
      • • Division of Cardiology
      • • Division of Cardiothoracic Surgery
      Los Angeles, California, United States
  • 2008
    • University of Pittsburgh
      Pittsburgh, Pennsylvania, United States
  • 1999–2003
    • Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center
      • Department of Medicine
      Torrance, California, United States
  • 2002
    • CSU Mentor
      Long Beach, California, United States
  • 1997–2002
    • Harbor-UCLA Medical Center
      Torrance, California, United States