Long‐term efficacy and safety of tailored immunosuppressive therapy in immune‐mediated biopsy‐proven myocarditis: A propensity‐weighted study

Abstract

AbstractAimsStandardized immunosuppressive therapy (IS) had been previously investigated in biopsy‐proven (BP) lymphocytic myocarditis with heart failure (HF). This study evaluated efficacy and safety of tailored IS in BP immune‐mediated myocarditis, irrespective of histology and clinical presentation.Methods and resultsConsecutive BP myocarditis patients treated with long‐term tailored IS on top of optimal medical therapy (OMT), were compared with OMT non‐IS controls using propensity‐score weighting. The primary outcome was a composite of death or heart transplant, the secondary outcome was a composite of biventricular function, New York Heart Association (NYHA) class variation, and relapse. IS was managed by a multidisciplinary Cardioimmunology Team, involved a safety checklist and active patients' education. Ninety‐one IS patients were compared with 267 non‐IS patients. IS patients more frequently had systemic immune‐mediated diseases (35% vs. 9.7%), lower baseline echocardiographic left ventricular ejection fraction (35% vs. 43%), lower right ventricular fractional area change (34% vs. 41%) and higher frequency of active lymphocytic, eosinophilic and giant cell myocarditis (71% vs. 58%, 12% vs. 1.1%, and 6.6% vs. 1.5%, respectively). At 5‐year follow up, no difference was observed in the primary outcome (survival rate 93% in IS vs. 87% in non‐IS), but IS patients had a higher relapse rate. Thus, IS patients, with a lower biventricular function and a higher risk profile at baseline, presented similar biventricular function and NYHA class to non‐IS patients at follow‐up. Minor adverse drug reactions occurred in 13% of patients, all resolved with therapy switch.ConclusionsProlonged tailored IS is effective and safe in BP immune‐mediated myocarditis irrespective of histology and clinical presentation.