Long-term outcomes of patients with tachycardia-induced cardiomyopathy

Abstract

Abstract Introduction Tachycardia-induced cardiomyopathy (TCM) is a reversible type of heart failure that occurs after sustained tachyarrhythmia. TCM can occur on its own (pure TCM) or superimposed on another type of CM (impure TCM). Survival data for such patients are lacking. Purpose We aimed to compare the 5-year survival rates of pure and impure TCM patients compared to other types of CM. Methods We retrospectively identified patients with reduced ejection fraction (≤50%) and/or atrial fibrillation or flutter with a left ventricular ejection fraction (LVEF) that improved from baseline (≥ 15% in LVEF at follow-up (FU)) through retrospective chart review. Patients were then divided into four groups (pure TCM, impure TCM, ischemic CM and nonischemic CM). The primary outcome was defined as a composite of death, life-threatening arrhythmia or cardiogenic shock. Secondary outcome was cardiovascular re-admission during FU. Results 238 patients were included (mean age 68 ± 12 years, 31% women). Patients were classified as pure TCM in 35%, impure TCM in 18%, ischemic CM in 24% and non-ischemic CM in 23%. Median FU was 5 (IQR 4-6) years. 13 (5.5%) patients reached the composite outcome at FU. While patients with pure TCM showed similar survival rates as patients with ischemic or nonischemic CM (Figure), a significant difference in survival was observed between impure CM and ischemic and non-ischemic CM with respect to the composite outcome (11% vs 2.7%, p = 0.024). Patients with impure CM showed comparable rates of cardiovascular re-admission during FU compared to patients with ischemic and non-ischemic CM (45% vs. 49%, p = 0.91). Conclusions TCM patients have survival rates similar to patients with another type of CM. Patients with TCM on top of a non-ischemic or ischemic CM (impure TCM) demonstrated the lowest 5-year survival rates. Early detection and treatment of cardiac arrhythmias in patients with impure TCM seem to be warranted.Figure