Alexander Iribarne

Factors Associated With Primary Graft Failure After Heart Transplantation

Background. Primary graft failure (PGF) is the most common cause of short-term mortality after cardiac transplantation. The low prevalence of PGF has limited efforts at identifying risk factors for its development. The purpose of this study was to evaluate risk factors associated with PGF after heart transplantation. Methods. Deidentified data were obtained from United Network for Organ Sharing. Analysis included heart transplant recipients more than or equal to 18 years transplanted between January 1, 1999, and December 31, 2007 (n=16,716). PGF was studied from the perspective of “hard outcomes” including death or retransplantation within 90 days of transplant due to graft failure, not related to rejection or infection. Multivariate regression analysis was performed (backward, remove P>0.15) to assess the simultaneous effect of multiple variables on PGF. The odds ratio and 95% confidence interval were reported for each factor. Results. Among the 414 heart transplants complicated by PGF, 354 (85.5%) recipients died and 60 (14.5%) were retransplanted. PGF accounted for 23.4% (n=364) of all deaths (n=1555) in the first 90 days posttransplant. Categories of pretransplant variables associated with PGF included: ischemic time, donor gender, donor age, multiorgan donation, center volume, extracorporeal membrane oxygenation, mechanical circulatory support, etiology of heart failure, and reoperative heart transplant. The area under the receiver operative characteristic curve for the multivariate model was 0.764 (0.733–0.796). Conclusions. Pretransplant recipient and donor characteristics are associated with PGF. Identification of risk factors may aid in understanding the mechanisms underlying PGF and in matching recipients with donors in efforts to diminish the high mortality associated with this complication.

High Lung Allocation Score Is Associated With Increased Morbidity and Mortality Following Transplantation

BACKGROUNDnThe lung allocation score (LAS) was initiated in May 2005 to allocate lungs based on medical urgency and posttransplant survival. The purpose of this study was to determine if there is an association between an elevated LAS at the time of transplantation and increased postoperative morbidity and mortality.nnnMETHODSnThe United Network for Organ Sharing provided de-identified patient-level data. Analysis included lung transplant recipients aged >or= 12 years who received transplants between April 5, 2006, and December 31, 2007 (n = 3,836). Recipients were stratified into three groups: LAS < 50 (n = 3,161, 83.87%), LAS 50 to 75 (n = 411, 10.9%), and LAS >or= 75 (n = 197, 5.23%), referred to as low LAS (LLAS), intermediate LAS (ILAS), and high LAS (HLAS), respectively. The primary outcome was posttransplant graft survival at 1 year. Secondary outcomes included length of stay and in-hospital complications.nnnRESULTSnHLAS recipients had significantly worse actuarial survival at 90 days and 1 year compared with LLAS recipients. When transplant recipients were stratified by disease etiology, a trend of decreased survival with elevated LAS was observed across all major causes of lung transplant. HLAS recipients were more likely to require dialysis or to have infections compared with LLAS recipients (P < .001). In addition, length of stay was higher in the HLAS group when compared with the LLAS group (P < .001).nnnCONCLUSIONSnHLAS is associated with decreased survival and increased complications during the transplant hospitalization. Whereas the LAS has improved organ allocation through decreased waiting list deaths and waiting list times, lower survival and higher morbidity among HLAS recipients suggests that continued review of LAS scoring is needed to ensure optimal long-term transplant survival.

Minimally invasive versus sternotomy approach for mitral valve surgery: a propensity analysis.

BACKGROUNDnOver the past decade, minimally invasive (MI) mitral valve surgery has grown in popularity. The purpose of this study was to compare both short- and long-term outcomes of mitral valve repair and replacement performed through a MI versus traditional sternotomy (ST) incision using a propensity analysis approach to account for differences in baseline risk.nnnMETHODSnFrom January 2000 to December 2008, a total of 1,121 isolated mitral valve operations were performed at our institution (548 ST, 573 MI). Data were retrospectively collected on all patients, and a logistic regression model was created to predict selection to a MI versus ST approach. Propensity scores were then generated based on the regression model and matched pairs created using 1:1 nearest neighbor matching. There were 382 matched pairs in the analysis for a total sample size of 764, or 68.2% of the original cohort. Major outcomes of interest included cardiopulmonary bypass time, cross-clamp time, hospital length of stay, major in-hospital complications, and both short- and long-term survival.nnnRESULTSnCardiopulmonary bypass time was 117.1 ± 2.0 minutes in the ST group and 139.7 ± 2.6 minutes in the MI group (p < 0.0001), and cross-clamp time was 79.6 ± 1.5 minutes in the ST group and 83.7 ± 1.9 in the MI group (p = 0.106). The average hospital length of stay was 9.81 ± 0.61 days among ST patients and 7.76 ± 0.37 days among MI patients (p = 0.0043). There was no significant difference in the frequency of major in-hospital complications between groups. The mean duration of survival follow-up was 4.2 ± 2.4 years. There was no significant difference in mortality at 30 days (p = 0.622) or 1 year (p = 0.599). In addition, there was no significant difference in long-term survival between groups (p = 0.569).nnnCONCLUSIONSnAlthough minimally invasive mitral valve surgery required a slightly longer cardiopulmonary bypass time, there was no difference in cross-clamp time, morbidity, or mortality, and hospital length of stay was significantly shorter when compared with matched sternotomy control patients.

Who Is the High-Risk Recipient? Predicting Mortality After Heart Transplant Using Pretransplant Donor and Recipient Risk Factors

BACKGROUNDnIn this study we sought the following: (1) To objectively assess the risk related to various pretransplant recipient and donor characteristics; (2) to devise a preoperative risk stratification score (RSS) based on pretransplant recipient and donor characteristics predicting graft loss at 1 year; and (3) to define different risk strata based on RSS.nnnMETHODSnThe United Network for Organ Sharing provided de-identified patient-level data. Analysis included 11,703 orthotopic heart transplant recipients aged 18 years or greater and transplanted between January 1, 2001 and December 31, 2007. The primary outcome was 1-year graft failure. Multivariable logistic regression analysis (backward p value<0.20) was used to determine the relationship between pretransplant characteristics and 1-year graft failure. Using the odds ratio for each identified variable, an RSS was devised. The RSS strata were defined by calculating receiver operating characteristic curves and stratum specific likelihood ratios.nnnRESULTSnThe strongest negative predictors of 1-year graft failure included the following: right ventricular assist device only, extracorporeal membrane oxygenation, renal failure, extracorporeal left ventricular assist device, total artificial heart, and advanced age. Threshold analysis identified 5 discrete RSS strata: low risk (LR, RSS: <2.55; n=3242, 27.7%), intermediate risk (IR, RSS: 2.55-5.72; n=6,347, 54.2%), moderate risk (MR, RSS: 5.73-8.13; n=1,543, 13.2%), elevated risk (ER, RSS: 8.14-9.48; n=310, 2.6%), and high risk (HR, RSS: >9.48; n=261, 2.2%). The 1-year actuarial survival (%) in the LR, IR, MR, ER, and HR groups were 93.8, 89.2, 81.3, 67.0, and 47.0, respectively.nnnCONCLUSIONSnPretransplant recipient variables significantly influence early and late graft failure after heart transplantation. The RSS may improve organ allocation strategies by reducing the potential negative impact of transplanting candidates who are at a high risk for poor postoperative outcomes.

Who is the high-risk recipient? Predicting mortality after lung transplantation using pretransplant risk factors.

OBJECTIVESnThe purpose of this study was to create a preoperative risk stratification score (RSS) based on pretransplant recipient characteristics that could be used to predict mortality following lung transplantation.nnnMETHODSnUnited Network for Organ Sharing provided de-identified patient-level data. The study population included 8780 adult recipients (age > 12 years) having lung transplantation from January 1, 1999, to December 31, 2006. Multivariate logistic regression (backward, P > .10) was performed. Using the odds ratio for each identified variable, an RSS was devised. The RSS included only pretransplant recipient variables and excluded donor variables.nnnRESULTSnThe strongest negative predictors of 1-year survival included extracorporeal membrane oxygenation, decreased estimated glomerular filtration rate, total bilirubin >2.0 mg/dL, recipient age, hospitalization at time of transplant, O(2) dependence, cardiac index <2, steroid dependence, donor:recipient weight ratio <0.7, all non-cystic fibrosis/chronic obstructive pulmonary disease etiologies, and female donor-to-male recipient. Threshold analysis identified 4 discrete groups: low risk, moderate, elevated risk, and high risk. The 1-year actuarial survival was 80.4% for the entire group, compared with 56.8% in the high-risk group (RSS > 7.2, n = 490; 6%).nnnCONCLUSIONnPretransplant recipient variables significantly influence both early and late survival following lung transplantation. Some patients face a higher than average risk of mortality during their first year posttransplant, which challenges the goals of equitable organ allocation. RSS may improve organ allocation strategies by avoiding the potential negative impact of performing transplantation in extremely high-risk candidates.

The golden age of minimally invasive cardiothoracic surgery: current and future perspectives

Over the past decade, minimally invasive cardiothoracic surgery (MICS) has grown in popularity. This growth has been driven, in part, by a desire to translate many of the observed benefits of minimal access surgery, such as decreased pain and reduced surgical trauma, to the cardiac surgical arena. Initial enthusiasm for MICS was tempered by concerns over reduced surgical exposure in highly complex operations and the potential for prolonged operative times and patient safety. With innovations in perfusion techniques, refinement of transthoracic echocardiography and the development of specialized surgical instruments and robotic technology, cardiac surgery was provided with the necessary tools to progress to less invasive approaches. However, much of the early literature on MICS focused on technical reports or small case series. The safety and feasibility of MICS have been demonstrated, yet questions remain regarding the relative efficacy of MICS over traditional sternotomy approaches. Recently, there has been a growth in the body of published literature on MICS long-term outcomes, with most reports suggesting that major cardiac operations that have traditionally been performed through a median sternotomy can be performed through a variety of minimally invasive approaches with equivalent safety and durability. In this article, we examine the technological advancements that have made MICS possible and provide an update on the major areas of cardiac surgery where MICS has demonstrated the most growth, with consideration of current and future directions.

Comparative effectiveness of minimally invasive versus traditional sternotomy mitral valve surgery in elderly patients

OBJECTIVESnThis study assessed comparative effectiveness of minimally invasive versus traditional sternotomy mitral valve surgery in elderly patients.nnnMETHODSnFrom January 1, 2000, to December 31, 2008, 1005 patients underwent isolated mitral valve surgery at our institution. Patients ≥ 75-years-old were included in analysis (sternotomy, n = 105; minimally invasive, n = 70). Clinical outcomes included bypass and crossclamp time, length of hospitalization, morbidity, and mortality. To assess resource use, total hospital costs and discharge location were analyzed. Three standardized inpatient functional status outcomes were also assessed.nnnRESULTSnThe minimally invasive approach was associated with a 9.2-minute longer crossclamp time (P = .037) and a 25.2-minute longer bypass time (P < .001). Minimally invasive surgery was associated with a 3.1-day shorter hospitalization (P = .033). There were no significant differences in rate of major postoperative complications (P = .085) or long-term survival (P = .60). Minimally invasive approach was associated with a

Does lung allocation score maximize survival benefit from lung transplantation

6721 lower median cost of hospitalization (P = .007) and more common discharge to home, routinely or with a health aide, rather than to rehabilitation (P = .021). Minimally invasive patients achieved faster rates of independent ambulation (P = .039) and independent sit-to-stand activity (P = .003), although there were no differences in time to independent stair climbing (P = .31).nnnCONCLUSIONSnAmong elderly patients, minimally invasive mitral valve surgery is associated with slightly longer crossclamp and bypass times but with equivalent morbidity and mortality and shorter hospitalization, decreased resource use, and improved postoperative functional status.

A Minimally Invasive Approach is More Cost-Effective than a Traditional Sternotomy Approach for Mitral Valve Surgery

OBJECTIVEnThe lung allocation score was initiated in May 2005 to allocate lungs on the basis of medical urgency and posttransplant survival. However, the relationship between lung allocation score and candidate outcomes remains poorly characterized. The purpose of this study was (1) to describe outcomes by lung allocation score at the time of listing and (2) to estimate the net survival benefit of transplantation by lung allocation score.nnnMETHODSnThe United Network for Organ Sharing provided de-identified patient-level data. Analysis included lung transplant candidates aged 12 years or more and listed between May 4, 2005, and May 4, 2009 (n = 6082). Candidates were stratified according to lung allocation score at listing into 7 groups: lung allocation score less than 40, 40 to 49, 50 to 59, 60 to 69, 70 to 79, 80 to 89, and 90 or more. Outcomes of interest included the risk of death on the waiting list and likelihood of transplantation. The net survival benefit of transplantation was defined as actuarial median posttransplant graft survival minus actuarial median waiting list survival, where the outcome of interest was death on the waiting list or posttransplant; candidates were censored at the time of transplant or last follow-up.nnnRESULTSnIn the lowest-priority strata (eg, <40 and 40-49), less than 4% of candidates died on the waiting list within 90 days of listing. The median net survival benefit was lowest in the lung allocation score less than 40 (-0.7 years) and lung allocation score 90+ group (1.95 years) and highest in the 50 to 59 (3.44 years), 60 to 69 (3.49 years), and 70 to 79 (2.81 years) groups.nnnCONCLUSIONSnThe mid-priority groups (eg, 50-59, 60-69, 70-79) seem to achieve the greatest survival benefit from transplantation. Although low-priority candidates comprise the majority of transplant recipients, survival benefit in this group seems to be less than in other groups given the low risk of death on the waiting list. As expected, both the time to transplant and survival on the waitlist are lower in the higher-priority strata (eg, 80-89 and 90+). However, their net survival benefit was likewise relatively low as a result of their poor posttransplant survival.

Quantifying the incremental cost of complications associated with mitral valve surgery in the United States.

OBJECTIVEnThe aim of this study was to compare the cost and effectiveness of a minimally invasive (MI) versus traditional sternotomy (ST) approach for mitral valve surgery (MVS).nnnMETHODSnFrom January 1, 2003, to December 31, 2008, a total of 847 patients underwent isolated MVS at our institution. Propensity matching on 22 clinical variables was carried out to generate a study cohort of 434 patients (217 matched pairs). Direct and indirect costs from the hospital perspective were retrospectively obtained from our finance department. Total hospital costs were further stratified into 13 standardized institutional billing categories. In addition, data on morbidity, mortality, discharge location, hospital readmissions within 1 year, and freedom from reoperation were obtained.nnnRESULTSnCompared with ST, MIMVS was associated with a