Immunosuppressive Therapy Improves Both Short- and Long-Term Prognosis in Patients With Virus-Negative Nonfulminant Inflammatory Cardiomyopathy

BACKGROUND: Inflammatory cardiomyopathy (infl-CMP) is characterized by increased cardiac inflammation in the absence of viruses, ischemia, valvular disease, or other apparent causes. Studies addressing the efficacy of immunosuppressive therapy in patients with infl-CMP are sparse. This study retrospectively investigates whether immunosuppressive agents on top of heart failure therapy according to current guidelines improves cardiac function and long-term outcome in patients with infl-CMP. METHODS AND RESULTS: Within the Innsbruck and Maastricht Cardiomyopathy Registry, a total of 209 patients fulfilled the criteria for infl-CMP using endomyocardial biopsy (>= 14 infiltrating inflammatory cells/mm(2)). A total of 110 (53%) patients received immunosuppressive therapy and 99 (47%) did not. To correct for potential selection bias, 1: 1 propensity score matching was used on all significant baseline parameters, resulting in a total of 90 patients per group. Baseline characteristics did not significantly differ between both patient groups, reflecting optimal propensity score matching. After a median follow-up of 31 (15-47) months, immunosuppressive therapy resulted in an improved long-term outcome (eg, heart transplantation-free survival) as compared with standard heart failure therapy alone (Log-rank P=0.043; hazard ratio, 0.34 [95% CI, 0.17-0.92]) and in a significant larger increase of left ventricular ejection fraction after a mean of 12 months follow-up, as compared with patients receiving standard heart failure treatment only (12.2% versus 7.3%, respectively; P=0.036). CONCLUSIONS: To conclude, this study suggests that immunosuppressive therapy in infl-CMP patients results in an improved heart transplantation-free survival as compared with standard heart failure therapy alone, underscoring the urgent need for a large prospective multicenter trial.