Atrial flutter and fibrillation in patients with pulmonary hypertension.

BACKGROUND: Atrial flutter and fibrillation are being increasingly reported in patients with pulmonary hypertension but little is known about their clinical implications. We sought to determine the incidence and clinical impact of these arrhythmias in patients with pulmonary hypertension.
METHODS: In a 5-year, prospective study, we assessed the incidence of new-onset atrial flutter and fibrillation as well as risk factors, clinical consequences, management, and impact on survival in patients with pulmonary arterial hypertension (PAH, n=157) or inoperable chronic thromboembolic pulmonary hypertension (CTEPH, n=82).
RESULTS: The cumulative 5-year incidence of new-onset atrial flutter and fibrillation was 25.1% (95% confidence interval, 13.8-35.4%). The development of these arrhythmias was frequently accompanied by clinical worsening (80%) and signs of right heart failure (30%). Stable sinus rhythm was successfully re-established in 21/24 (88%) of patients initially presenting with atrial flutter and in 16/24 (67%) of patients initially presenting with atrial fibrillation. New-onset atrial flutter and fibrillation were an independent risk factor of death (p=0.04, simple Cox regression analysis) with a higher mortality in patients with persistent atrial fibrillation when compared to patients in whom sinus rhythm was restored (estimated survival at 1, 2 and 3 years 64%, 55%, and 27% versus 97%, 80%, and 57%, respectively; p=0.01, log rank analysis).
CONCLUSIONS: Atrial flutter and fibrillation develop in a sizable number of patients with PAH or inoperable CTEPH and often lead to clinical deterioration and right heart failure. Mortality is high when sinus rhythm cannot be restored.