Tachycardiomyopathy: long-term characteristics of this novel subsetting of acute heart failure

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 forms of HFrEF.

We conducted a prospective observational study hospitalized with de novo, acute decompensated HFrEF, classified into pure TCM, impure TCM, idiopathic HF, and structural HF (ischemic and valvular). Follow-up included clinical and echocardiographic assessments, tracking all-cause mortality and unplanned cardiovascular hospitalizations. Survival analysis was conducted using Kaplan-Meier, and group comparisons utilized ANOVA and chi-square tests.

We consecutively enrolled 456 patients (304 males, median age 72.8 years) and divided them into the four groups previously described (Table 1). The median follow-up was 3 years (IQR 1.5-5.1 years).

TCM was mainly due to atrial fibrillation (128 patients, 75.7%). A rhythm control strategy was chosen to treat the acute TCM phase in 135 patients (79.9%): electric cardioversion was performed in 60.9% of all TCM, 8.3% underwent pharmacological conversion and 10.7% went straight to ablation during the first hospitalization. All four subgroups experienced changes in clinical and laboratory parameters during hospitalization, with a significant improvement of NYHA class before discharge and a concomitant reduction of BNP.

The four groups had significantly different estimates for all-cause death, with pure TCM having the highest survival rate and structural HF having the lowest survival rate over the follow-up (Figure 1). Using structural HF as a comparator, HRs for death were significantly lower for patients with pure TCM (HR 0.34; 95% CI 0.21-0.56) and idiopathic HF (HR 0.53; 95% CI 0.32-0.90), while impure TCM did not differ (HR 0.57; 95% CI 0.30-1.07). Within the TCM groups, an initial rhythm control strategy was associated with better overall survival (73% vs. 50%; log-rank p<0.0001). Unplanned hospitalizations showed a different trend compared to all cause-mortality, with pure and impure TCM having the lowest free-from-readmission estimates over follow-up (Figure 2). Moreover, the average total number of unplanned hospitalizations also differed significantly between the four groups (pure TCM 0.81; 95% CI 0.62-1.00; impure TCM 0.84; 95% CI 0.51-1.17; idiopathic HF 0.38; 95% CI 0.20-0.55; structural HF 0.89; 95% CI 0.68-1.10; p=0.019).

Pure TCM shows a favorable survival prognosis but high readmission rates, emphasizing the need for early rhythm control and sustained monitoring for arrhythmia recurrence. Structured, long-term follow-up may benefit TCM patients, and further research is needed to clarify the impact of rhythm control on quality of life and hospitalization reduction.

Survival