Prognostic Impact of Atrial Fibrillation in Electrical Storm

Data regarding the prognostic impact of atrial fibrillation (AF) in patients with electrical storm (ES) is rare.

This study sought to assess the prognostic impact of AF in patients with ES on mortality, rehospitalization, major adverse cardiovascular events (MACE) and recurrence of ES (ES-R).

All consecutive implantable cardioverter defibrillator (ICD) patients presenting with ES were included retrospectively from 2002 to 2016. Patients with AF were compared to non-AF patients. The primary prognostic endpoint was all-cause mortality. Secondary endpoints were in-hospital mortality, rehospitalization rates, MACE and ES-R.

A total of 87 ES patients with ICD were included and followed up to 2.5 years; 43% suffered from AF. The presence of AF was associated with increased all-cause mortality (47 vs. 29%, log-rank p = 0.052; hazard ratio [HR] 1.969, 95% confidence interval [CI] 0.981-3.952, p = 0.057), which was no longer present after multivariable adjustment for age, diabetes and dilated cardiomyopathy. Furthermore, AF was associated with increased rates of overall rehospitalization (61 vs. 31%, log-rank p = 0.013; HR 2.381, 95% CI 1.247-4.547, p = 0.009), especially due to AF (14 vs. 0%, p = 0.001) and acute heart failure (AHF) (28 vs. 10%, p = 0.018; HR 3.754, 95% CI 1.277-11.038, p = 0.016). Notably, AF was not associated with differences in MACE (55 vs. 37%, log rank p = 0.339) and ES-R (28 vs. 25%, log rank p = 0.704).

In ES patients, presence of AF was univariably associated with increased rates of all-cause mortality at 2.5 years. Furthermore, AF was multivariably associated with overall rehospitalization, especially due to AF and AHF.