Single- vs double-lung transplantation in patients with chronic obstructive pulmonary disease and idiopathic pulmonary fibrosis since the implementation of lung allocation based on medical need.

IMPORTANCE: Outcomes of single- and double-lung transplantation have not been rigorously assessed since the allocation of donor lungs according to medical need as quantified by the Lung Allocation Score, which began in 2005. OBJECTIVE: To compare outcomes in single- and double-lung transplant recipients since the Lung Allocation Score was implemented. DESIGN, SETTING, AND PARTICIPANTS: In this exploratory analysis, adults with idiopathic pulmonary fibrosis (IPF) or chronic obstructive pulmonary disease (COPD) who underwent lung transplantation in the United States between May 4, 2005, and December 31, 2012, were identified in the United Network for Organ Sharing thoracic registry, with follow-up to December 31, 2012. Posttransplantation graft survival was assessed with Kaplan-Meier analysis. Propensity scores were used to control for treatment selection bias. A multivariable flexible parametric prognostic model was used to characterize the time-varying hazard associated with single- vs double-lung transplantation. EXPOSURE: Single- or double-lung transplantation. MAIN OUTCOMES AND MEASURES: Composite of posttransplant death and graft failure (retransplantation). RESULTS: Patients with IPF (n = 4134, of whom 2010 underwent single-lung and 2124 underwent double-lung transplantation) or COPD (n = 3174, of whom 1299 underwent single-lung and 1875 underwent double-lung transplantation) were identified as having undergone lung transplantation since May 2005. Median follow-up was 23.5 months. Of the patients with IPF, 1380 (33.4%) died and 115 (2.8%) underwent retransplantation; of the patients with COPD, 1138 (34.0%) died and 59 (1.9%) underwent retransplantation. After confounders were controlled for with propensity score analysis, double-lung transplants were associated with better graft survival in patients with IPF (adjusted median survival, 65.2 months [interquartile range {IQR}, 21.4-91.3 months] vs 50.4 months [IQR, 17.0-87.5 months]; P < .001) but not in patients with COPD (adjusted median survival, 67.7 months [IQR, 25.2-89.6 months] vs 64.0 months [IQR, 25.2-88.7 months]; P = .23). The interaction between diagnosis type (COPD or IPF) and graft failure was significant (P = .049). Double-lung transplants had a time-varying association with graft survival; a decreased instantaneous late hazard for death or graft failure among patients with IPF was noted at 1 year and persisted at 5 years postoperatively (instantaneous hazard at 5 years, hazard ratio, 0.67 [95% CI, 0.52-0.84] in patients with IPF and 0.89 [95% CI, 0.71-1.13] in patients with COPD). CONCLUSIONS AND RELEVANCE: In an exploratory analysis of registry data since implementation of a medical need-based lung allocation system, double-lung transplantation was associated with better graft survival than single-lung transplantation in patients with IPF. In patients with COPD, there was no survival difference between single- and double-lung transplant recipients at 5 years.

Adoption and effectiveness of internal mammary artery grafting in coronary artery bypass surgery among Medicare beneficiaries.

OBJECTIVES: The aim of this study was to assess the pattern of the adoption of internal mammary artery (IMA) grafting in the United States, test its association with clinical outcomes, and assess whether its effectiveness differs in key clinical subgroups. BACKGROUND: The effect of IMA grafting on major clinical outcomes has never been tested in a large randomized trial, yet it is now a quality standard for coronary artery bypass graft (CABG) surgery. METHODS: We identified Medicare beneficiaries ≥66 years of age who underwent isolated multivessel CABG between 1988 and 2008, and we documented patterns of IMA use over time. We used a multivariable propensity score to match patients with and without an IMA and compared rates of death, myocardial infarction (MI), and repeat revascularization. We tested for variations in IMA effectiveness with treatment × covariate interaction tests. RESULTS: The IMA use in CABG rose slowly from 31% in 1988 to 91% in 2008, with persistent wide geographic variations. Among 60,896 propensity score-matched patients over a median 6.8-year follow-up, IMA use was associated with lower all-cause mortality (adjusted hazard ratio: 0.77, p < 0.001), lower death or MI (adjusted hazard ratio: 0.77, p < 0.001), and fewer repeat revascularizations over 5 years (8% vs. 9%, p < 0.001). The association between IMA use and lower mortality was significantly weaker (p ≤ 0.008) for older patients, women, and patients with diabetes or peripheral arterial disease. CONCLUSIONS: Internal mammary artery grafting was adopted slowly and still shows substantial geographic variation. IMA use is associated with lower rates of death, MI, and repeat coronary revascularization.

Transplantation for idiopathic pulmonary arterial hypertension: improvement in the lung allocation score era.

BACKGROUND: Lung transplantation and heart-lung transplantation represent surgical options for treatment of medically refractory idiopathic pulmonary arterial hypertension. The effect of the lung allocation score on wait-list and transplantation outcomes in patients with idiopathic pulmonary arterial hypertension is poorly described. METHODS AND RESULTS: Adults diagnosed with idiopathic pulmonary arterial hypertension and listed for transplantation in the 80 months before and after the lung allocation score algorithm was implemented (n=1430) were identified in the United Network for Organ Sharing thoracic registry. Patients were stratified by organ listed and pre- and post-lung allocation score era. The cumulative incidences of transplantation and mortality for wait-listed patients in both eras were appraised with competing outcomes analysis. Posttransplantation survival was assessed with the Kaplan-Meier method. These analyses were repeated in propensity-matched subgroups. Cox proportional hazards analysis evaluated the effect of prelisting and pretransplantation characteristics on mortality. We found that patients in the post-lung allocation score era had significantly worse comorbidities; nevertheless, both lung transplantation and heart-lung transplantation candidates in this era enjoyed lower wait-list mortality and a higher incidence of transplantation in unmatched and propensity-matched analyses. On multivariable analysis, heart-lung transplantation and double-lung transplantation were associated with improved survival from the time of wait-listing, as was being listed at a medium- to high-volume institution. Donor/recipient sex matching predicted posttransplantation survival. CONCLUSIONS: The incidence of transplantation has increased while wait-list mortality has decreased in patients with idiopathic pulmonary arterial hypertension wait-listed for transplantation in the post-lung allocation score era. Both heart-lung transplantation and double-lung transplantation are predictive of survival in transplantation candidates with idiopathic pulmonary arterial hypertension, as is being listed at a medium- to high-volume institution. Donor/recipient sex matching is associated with better posttransplantation survival.