BACKGROUND: Atrial fibrillation (AF) in heart failure (HF) patients has been associated with a worse outcome. Similarly, excessive supraventricular ectopic activity (ESVEA) has been linked to development of AF, stroke and death. This study aimed to investigate AF and ESVEA's association with outcomes and effect of prophylactic implantable cardioverter defibrillator (ICD) implantation in non-ischemic HF patients.

METHODS: A total of 850 patients with non-ischemic HF, left ventricle ejection fraction ≤35%, and elevated N-terminal pro-brain natriuretic peptides underwent 24-hours Holter recording. The presence of AF (≥30 seconds) and ESVEA (≥30 supraventricular ectopic complexes (SVEC) per hour or run of SVEC ≥20 beats) were registered. Outcomes were all-cause mortality, cardiovascular death (CVD) and sudden cardiac death (SCD).

RESULTS: AF was identified in 188 patients (22%), and ESVEA in 84 patients (10%). After 4 years and 11 months of follow-up, a total of 193 patients (23%) had died. AF was associated with all-cause mortality (HR 1.44; CI 1.04-1.99; P=0.03) and CVD (HR 1.59; CI 1.07-2.36; P=0.02). ESVEA was associated with all-cause mortality (HR 1.73; CI 1.16-2.57; P=0.0073) and CVD (HR 1.76; CI 1.06-2.92; P=0.03). Neither AF nor ESVEA was associated with SCD. ICD implantation was not associated with an improved prognosis for neither AF (P-value for interaction=0.17), nor ESVEA (P-value for interaction=0.68).

CONCLUSION: Both AF and ESVEA were associated with worsened prognosis in non-ischemic HF. However, ICD implantation was not associated with an improved prognosis for either group.