Long-term prognosis of pure and impure tachycardiomyopathy

Background and aims: Tachycardia-induced cardiomyopathy (TCM) is a reversible form of heart failure (HF) driven by arrhythmias, often atrial fibrillation (AF). While reversible, TCM's long-term prognosis remains unclear, especially in comparison to HF with reduced ejection fraction (HFrEF). This study examines the prognosis of pure and impure TCM against other causes of HFrEF. Methods: Prospective, monocentric, observational study of 456 patients hospitalized with de novo, acute decompensated HFrEF, classified into pure TCM, impure TCM, ischaemic HF and non-ischaemic HF. The primary endpoint was all-cause mortality, and the secondary endpoint was the incidence of unplanned cardiovascular hospitalisations. Sensitivity analyses were performed using propensity score matching between the four groups. Results: During a median follow-up of 3 years (interquartile range 1.5–5.1 years), pure TCM had the highest survival rate, and ischaemic HF had the lowest (pure TCM 78.2%; impure TCM 64.8%; non-ischaemic HF 73.4%; ischaemic HF 58.5%; log-rank P < 0.0001). Pure and impure TCM presented the lowest free-from-readmission estimates over follow-up (pure TCM 43.2%; impure TCM 60.0%; non-ischaemic HF 83.2%; ischaemic HF 69.9%; log-rank P < 0.0001). An initial rhythm control strategy was associated with better overall survival in TCM (79% vs. 63%; log-rank P < 0.0001) but similar rates of unplanned hospitalization. Conclusions: Pure TCM shows a favourable survival prognosis but high readmission rates, emphasizing the need for early rhythm control and sustained monitoring for arrhythmia recurrence. An initial rhythm control strategy seems associated with an increased survival, highlighting the importance of early recognition of arrhythmias as a culprit of HF worsening.