Abstract 8894: Impact of Troponin I-Autoantibodies in Chronic Dilated and Ischemic Cardiomyopathy
Background: The aim of this study was to investigate the prognostic value of circulating troponin I (TNI)-autoantibodies in plasma of patients with chronic heart failure.
Methods: Sera of 390 heart failure patients were tested for presence of anti-TNI antibodies by Enzyme-linked immunosorbent assay (ELISA), including 249 (63.8 percent of total) patients with dilated cardiomyopathy (DCM) and 141 (36.2 percent of total) patients with ischemic cardiomyopathy (ICM). 72 patients (18.5 percent of total) were female and 318 patients (81.5 percent of total) male. Mean patient age was 54.6 ± 11.3 years and mean follow-up time was 3.8 ± 3.2 years.
Results: TNI-autoantibodies (titre of ≥1:40) were detected in 73 out of 390 patients (18.7 percent of total). In TNI-autoantibody positive patients mean left ventricular ejection fraction (LVEF) was 27.6 ± 5.8 percent, compared to 25.8 ± 5.9 percent in TNI-autoantibody negative patients, P=0.03. The combined end-point of death (n=118, 30.3 percent of total) or heart transplantation (HTX) (n=44, 11.3 percent of total) was reached in 162 patients (41.5 percent of total). Kaplan-Meyer analysis demonstrated superior survival (combined end-point of death or HTX) in patients with DCM vs. ICM (P=0.0198) and TNI-autoantibody positive patients vs. TNI-autoantibody negative patients (P=0.0348). Further subgroup analysis revealed a favourable outcome in TNI-positive patients with heart failure if the patients suffered from DCM (P=0.0334), whereas TNI-autoantibody status in patients with ICM was not associated with survival (P=0.8486). In subsequent multivariate Weibull-analysis, a positive TNI serostatus was associated with a significantly lower all-cause mortality in DCM patients (P=0.0448).
Conclusions: The presence of TNI-autoantibodies in plasma is associated with an improved survival in patients with chronic DCM, but not ICM. This might possibly indicate a prophylactic effect of TNI-autoantibodies in this subgroup of patients, encouraging further studies into possible protective effects of antibodies against certain cardiac target structures.
- © 2010 by American Heart Association, Inc.