Clinical impact of atrial fibrillation in patients with the HeartMate II left ventricular assist device.

Background: Atrial fibrillation (AF) is common in patients with the HeartMate II (HMII) left ventricular assist device (LVAD), but the impact of AF on clinical outcomes is uncertain.

Objectives: This study sought to determine the effect of AF on outcomes in patients with the HMII LVAD.

Methods: Records of 106 patients who underwent HMII implantation at a single center were reviewed. The associations of paroxysmal atrial fibrillation (PAF) and persistent atrial fibrillation (PeAF) with survival, heart failure (HF) hospitalization, bleeding, and thromboembolism were examined using Kaplan-Meier survival analysis and Cox proportional hazards regression.

Results: Mean age was 56.6 ± 11.4 years, 87.7% of the implants were intended as a bridge to transplantation, and median length of support was 217 days (range: 1 to 952 days). AF was present in 55 patients (51.9%); 36 patients (34.0%) had PAF and 19 (17.9%) had PeAF. Twenty-one patients (19.8%) died, and 18 (17.0%) were hospitalized for HF. There were 0.75 major bleeding events and 0.28 thromboembolic events per patient year of follow-up. PAF was not associated with increased mortality, HF hospitalization, bleeding, or thromboembolism. PeAF, however, was an independent predictor of the composite endpoint of death or HF hospitalization (hazard ratio: 3.54; 95% confidence interval: 1.52 to 8.25; p < 0.01). Although there was no increase in bleeding or thromboembolism, patients with AF had thromboembolic events at higher international normalized ratios (INRs).

Conclusions: Although PAF is not associated with worse outcomes in patients with the HMII LVAD, PeAF may be associated with increased mortality and HF hospitalization. Patients with AF also may have thromboembolic events at higher INR levels.