Heart failure and atrial fibrillation: tachycardia-mediated acute decompensation

Aims: Tachycardia is a reversible event that may cause hemodynamic decompensation but may not necessarily cause direct damages to the myocardium. To evaluate the clinical outcomes of patients with heart failure (HF) and atrial fibrillation (AF), whose acute decompensation was tachycardia mediated. Methods and results: The Korean Acute Heart Failure registry was a prospective registry that consecutively enrolled 5625 patients with acute HF. Patients were classified into three groups according to the rhythm and aggravating factor: (i) 3664 (65.1%) patients with sinus rhythm (SR), (ii) 1033 (18.4%) patients with AF whose decompensation was tachycardia-mediated, AF-TM (+), and (iii) N = 928 (16.5%) patients with AF whose decompensation was not tachycardia-mediated, AF-TM (-). The primary outcomes were in-hospital and post-discharge 1 year all-cause mortality. At admission, the mean heart rate was 90.8 ± 23.4, 86.8 ± 26.8, and 106.3 ± 29.7 beats per minute for the SR, AF-TM (-), and AF-TM (+) groups, respectively. The AF-TM (+) group had more favourable characteristics such as de novo onset HF, less diabetes, ischaemic heart disease, and higher blood pressure than the AF-TM (-) group. In-hospital mortality rates were 5.1%, 6.5%, and 1.7% for SR, AF-TM (-), and AF-TM (+) groups, respectively. In logistic regression analysis, the AF-TM (+) group had lower in-hospital mortality after adjusting the significant covariates (odds ratio, 0.49; 95% confidence interval, 0.26-0.93). The mortality rate did not differ between SR and AF-TM (-) groups. During 1 year follow-up, 990 (18.5%) patients died. In univariate and multivariate Cox proportional regression analyses, there was no difference in 1-year all-cause mortality between the three groups. Conclusions: In patients with HF and AF, patients whose acute decompensation is tachycardia-mediated have better in-hospital, but similar post-discharge outcomes compared with those with SR or those with AF whose decompensation is not tachycardia-mediated. Clinical trial registration: ClinicalTrial.gov NCT01389843.ope