A clinical correlation study of severity of antibody-mediated rejection and cardiovascular mortality in heart transplantation.

BACKGROUND: The current International Society for Heart and Lung Transplantation (ISHLT) diagnostic criteria for antibody-mediated rejection (AMR) designate AMR as either absent (AMR 0) or present (AMR 1), without grading its severity. Yet, the extent of histologic and immunofluorescence (IF) findings of AMR varies across endomyocardial biopsies (EMBs). In this study, we hypothesized that the severity of AMR, as assessed on EMBs, correlates with cardiovascular mortality in heart transplant recipients. METHODS: All EMBs from 1985 to 2005 were evaluated. Biopsy specimens were uniformly studied by light microscopy and IF early post-transplant. A comprehensive vascular score (V1: no AMR, to V5: severe AMR) was prospectively assigned to each EMB, based on severity of both histologic and IF findings. Univariate Cox proportional hazards regressions were performed using indicators of vascular scores alone, combined, and cumulatively. RESULTS: Nine hundred six patients were transplanted and included in the study. Mean age was 46.6 +/- 15.5 years and 82% were male. A total of 26,236 EMBs comprised the study data. As expected, histologic and immunopathologic findings of AMR varied in severity. An incremental risk of cardiovascular mortality was found with more severe AMR whether vascular scores were analyzed individually (p = 0.001), in combination (p = 0.01) or cumulatively (p = 0.006). CONCLUSIONS: The severity of AMR on EMBs correlates with an incremental cardiovascular mortality risk after heart transplantation, suggesting that AMR should be viewed as a spectrum rather than just as present or absent. Supplementing the ISHLT AMR diagnostic guidelines with a consensus severity scale is warranted.

Long-term outcomes of cardiac transplantation for peri-partum cardiomyopathy: a multiinstitutional analysis.

BACKGROUND: Outcomes of patients with a prior diagnosis of peri-partum cardiomyopathy (PPCM) undergoing heart transplantation are not well described but may be worse than for women who undergo transplantation for other etiologies. METHODS: Between 1999 and 2005, 69 women aged younger than 40 underwent transplantation for PPCM in 29 institutions participating in the Cardiac Transplant Research Database. Patients with PPCM were compared with 90 female recipients of similar age with idiopathic dilated cardiomyopathy (IDC) and history of pregnancy (P+), 53 with no prior pregnancy (P-), and with 459 men of a similar age with IDC. Rejection, infection, cardiac allograft vasculopathy, and survival were compared. RESULTS: Recipients with PPCM accounted for 1% of all transplants and 5% of transplants in women. Comparisons of the 4 patient groups were made. The risk of cumulative rejection was higher in the PPCM Group compared with the P- Group (p < 0.04) and the men (p < 0.0001). Cumulative risk of infection was lowest in the PPCM Group. Freedom from cardiac allograft vasculopathy was similar or higher in the PPCM Group compared with the other groups. Finally, the long-term survival of PPCM patients was comparable with the survival of men (p = 0.9), and there was a trend toward improved survival compared with the P+ Group (p = 0.07) and improved survival compared with the P- Group (p = 0.05). CONCLUSIONS: Heart transplantation for PPCM remains relatively infrequent. Survival and freedom from cardiac allograft vasculopathy in patients who receive a transplant for PPCM are no worse than in women who require a transplant for other indications, regardless of parity.

Multivariate predictors of heart transplantation outcomes in the era of chronic mechanical circulatory support.

BACKGROUND: Determining which pretransplantation (TX) characteristics predict the development of chronic renal dysfunction (CRD) or death after heart TX would enable more accurate risk assessment at the time of candidate evaluation. METHODS: A cohort of 278 patients underwent TX in three hospitals between 1993 and 2002. Predictive models for CRD (serum creatinine consistently above 2 mg/dL) and allograft loss (death or re-TX) were constructed using logistic and Cox regression, respectively. RESULTS: Using logistic regression, CRD was more likely to develop in TX patients if they had a larger body surface area (odds ratio [OR] = 5.8 per m2, 95% confidence interval [CI] = 1.04 to 31.9, p = 0.04) or were inotrope dependent (OR = 1.8, 95% CI = 0.90 to 3.7, p = 0.09). Notably, the implementation of mechanical circulatory support as bridge to transplantation decreased the risk of CRD (OR = 0.30, 95% CI = 0.12 to 0.72, p = 0.007). Cox analysis demonstrated independent predictive ability of improved survival for males (hazard ratio [HR] = 0.42, 95% CI = 0.21 to 0.83, p = 0.01). Worse survival was observed with prior sternotomy (HR = 3.5, 95% CI = 2.0 to 6.0, p < 0.001), diabetes mellitus (HR = 1.9, 95% CI = 0.98 to 3.9, p = 0.06), and elevated serum creatinine (HR = 2.8 per mg/dL, 95% CI = 1.3 to 5.8, p = 0.007). CONCLUSIONS: Certain pretransplant characteristics clearly predispose a patient to the development of CRD or increased mortality after heart transplantation. Interestingly, the risk of CRD after heart transplantation is greater for patients bridged to transplant with inotropes than with mechanical circulatory support. When hemodynamically indicated, timely implementation of pretransplant mechanical circulatory support should be considered.