The utility of 6-minute walk distance in predicting waitlist mortality for lung transplant candidates.

BACKGROUND The lung allocation score (LAS) has led to improved organ allocation for transplant candidates. At present, the 6-minute walk distance (6MWD) is treated as a binary categorical variable of whether or not a candidate can walk more than 150 feet in 6 minutes. In this study, we tested the hypothesis that 6MWD is presently under-utilized with respect to discriminatory power, and that, as a continuous variable, could better prognosticate risk of waitlist mortality. METHODS A retrospective cohort analysis was performed using the Organ Procurement and Transplantation Network/United Network for Organ Sharing (OPTN/UNOS) transplant database. Candidates listed for isolated lung transplant between May 2005 and December 2011 were included. The population was stratified by 6MWD quartiles and unadjusted survival rates were estimated. Multivariable Cox proportional hazards modeling was used to assess the effect of 6MWD on risk of death. The Scientific Registry of Transplant Recipients (SRTR) Waitlist Risk Model was used to adjust for confounders. The optimal 6MWD for discriminative accuracy in predicting waitlist mortality was assessed by receiver-operating characteristic (ROC) curves. RESULTS Analysis was performed on 12,298 recipients. Recipients were segregated into quartiles by distance walked. Waitlist mortality decreased as 6MWD increased. In the multivariable model, significant variables included 6MWD, male gender, non-white ethnicity and restrictive lung diseases. ROC curves discriminated 6-month mortality was best at 655 feet. CONCLUSIONS The 6MWD is a significant predictor of waitlist mortality. A cut-off of 150 feet sub-optimally identifies candidates with increased risk of mortality. A cut-off between 550 and 655 feet is more optimal if 6MWD is to be treated as a dichotomous variable. Utilization of the LAS as a continuous variable could further enhance predictive capabilities

Simultaneous Versus Sequential Heart-liver Transplantation: Ideal Strategies for Organ Allocation

Background. Simultaneous heart-liver (SHL) transplantation is an efficacious therapeutic modality for patients with combined heart and liver failure. However, the extent to which heart transplantation followed by sequential liver transplantation (LAH) can match the benefit of simultaneous transplantation has not previously been examined. Our objective was to determine if LAH offers comparable survival to SHL. Methods. The Organ Procurement and Transplantation Network/United Network for Organ Sharing Standard Transplant Analysis and Research file was queried for adult recipients waitlisted for both heart and liver transplantation. The United Network for Organ Sharing thoracic and liver databases were linked to facilitate examination of waitlist and transplant characteristics for simultaneously listed patients. Univariate survival analysis was used to determine overall survival. Results. Of the 236 patients meeting inclusion criteria, 200 underwent SHL, 7 sequentially underwent LAH, and 29 received heart transplantation only (isolated orthotopic heart transplantation [iOHT]). Recipients of SHL were less likely to have an episode of acute rejection before discharge (LAH, 14.2%; SHL, 2.4%; iOHT, 3.6%; P = .019) or be treated for acute rejection within 1 year after transplantation (LAH, 14.3%; SHL, 2.5%; iOHT, 13.8%; P = .007). Otherwise, postoperative hospital length of stay, stroke, need for dialysis, and need for pacemaker placement were comparable across groups. Ten-year survival similarly favored both LAH and SHL over iOHT (LAH: 100%, 71.4%, 53.6%; SHL: 87.1%, 80.4%, 52.1%, iOHT: 70.1%, 51.6%, 27.5% for 1-, 5-, and 10-year survivals, respectively, P = .003). However, median time between heart and liver transplant was 302 days in patients undergoing sequential transplantation. Conclusions. Although transplantation in a simultaneous or sequential fashion yields equivalent outcomes, a high fraction of patients undergoing initial heart transplant alone fail to proceed to subsequent liver transplantation. Therefore, in patients with combined heart and liver failure with a projected need for 2 allografts, simultaneous transplantation is associated with maximum benefit

Impact of Microbiological Organism Type on Surgically Managed Endocarditis.

BACKGROUND: This study describes the impact of organism and valve type on surgically managed infective endocarditis (IE) from The Society of Thoracic Surgeons (STS) database. We developed a risk model for surgically managed endocarditis that includes the microbiological organism. METHODS: The STS database was queried for adult patients with surgically managed endocarditis from July 1, 2011, to June 30, 2016. Outcomes were compared based on (1) causative microbiological organism, (2) valve type (native vs prosthetic), and (3) endocarditis on the right (tricuspid) vs left (mitral, aortic) sides. Univariate and risk adjusted models were developed with odds ratios for mortality for each organism type referenced against Streptococcus. RESULTS: The study population included 21,388 operations (93%) for left-sided IE and 1698 (7%) for right-sided IE. Streptococcus (28%) and Staphylococcus (27%) were the most common infecting organisms, followed by Enterococcus (11%). After multivariate adjustment, microbiological organism type was significantly associated with operative mortality for patients with left-sided endocarditis, with an adjusted odds ratio of 2.9 for fungal, 1.4 for Staphylococcus, and 1.3 for culture-negative vs Streptococcus. For right-sided endocarditis, there were no differences in outcomes by organism type. Left-sided prosthetic valve endocarditis had a higher operative mortality than left-sided native valve endocarditis (12% vs 8%, P \u3c .001). In contrast, surgery for right-sided endocarditis carried lower operative mortality, with no mortality difference between prosthetic valve endocarditis and native valve endocarditis (5% vs 4%, P = .6). CONCLUSIONS: Organism type influences the operative mortality for left-sided endocarditis. Surgery for left-sided and prosthetic valve endocarditis is associated with higher operative mortality. Risk adjustment for operative outcomes in endocarditis may need to account for microbiological organism type

Relationship of body mass index with outcomes after transcatheter aortic valve replacement: Results from the national cardiovascular data–STS/ACC TVT registry

Objective: To investigate the relationship of body mass index (BMI) with short- and long-term outcomes after transcatheter aortic valve replacement (TAVR). Patients and Methods: The relationship between BMI and baseline characteristics and procedural characteristics was assessed for 31,929 patients who underwent TAVR between November 1, 2011, and March 31, 2015, from the STS/ACC TVT Registry. Registry data on 20,429 patients were linked to the Centers for Medicare and Medicaid Services to assess the association of BMI with 30-day and 1-year mortality using multivariable Cox proportional hazards models. The effect of BMI on mortality was also assessed with BMI as a continuous variable. Restricted cubic regression splines were used to model the effect of BMI and to determine appropriate cut points of BMI. Results: Among 31,929 patients, 806 (2.5%) were underweight (BMI

Concomitant Tricuspid Repair in Patients with Degenerative Mitral Regurgitation

Background: Tricuspid regurgitation is common in patients with severe degenerative mitral regurgitation. However, the evidence base is insufficient to inform a decision about whether to perform tricuspid-valve repair during mitral-valve surgery in patients who have moderate tricuspid regurgitation or less-than-moderate regurgitation with annular dilatation. Methods: We randomly assigned 401 patients who were undergoing mitral-valve surgery for degenerative mitral regurgitation to receive a procedure with or without tricuspid annuloplasty (TA). The primary 2-year end point was a composite of reoperation for tricuspid regurgitation, progression of tricuspid regurgitation by two grades from baseline or the presence of severe tricuspid regurgitation, or death. Results: Patients who underwent mitral-valve surgery plus TA had fewer primary-end-point events than those who underwent mitral-valve surgery alone (3.9% vs. 10.2%) (relative risk, 0.37; 95% confidence interval [CI], 0.16 to 0.86; P = 0.02). Two-year mortality was 3.2% in the surgery-plus-TA group and 4.5% in the surgery-alone group (relative risk, 0.69; 95% CI, 0.25 to 1.88). The 2-year prevalence of progression of tricuspid regurgitation was lower in the surgery-plus-TA group than in the surgery-alone group (0.6% vs. 6.1%; relative risk, 0.09; 95% CI, 0.01 to 0.69). The frequencies of major adverse cardiac and cerebrovascular events, functional status, and quality of life were similar in the two groups at 2 years, although the incidence of permanent pacemaker implantation was higher in the surgery-plus-TA group than in the surgery-alone group (14.1% vs. 2.5%; rate ratio, 5.75; 95% CI, 2.27 to 14.60). Conclusions: Among patients undergoing mitral-valve surgery, those who also received TA had a lower incidence of a primary-end-point event than those who underwent mitral-valve surgery alone at 2 years, a reduction that was driven by less frequent progression to severe tricuspid regurgitation. Tricuspid repair resulted in more frequent permanent pacemaker implantation. Whether reduced progression of tricuspid regurgitation results in long-term clinical benefit can be determined only with longer follow-up. (Funded by the National Heart, Lung, and Blood Institute and the German Center for Cardiovascular Research; ClinicalTrials.gov number, NCT02675244.)