Abstract 14098: Epidemiology and Clinical Outcomes of Cardiac Arrhythmias in Pulmonary Arterial Hypertension

Background: There is limited evidence regarding the impact of cardiac arrhythmias in patients with pulmonary arterial hypertension (PAH). We aim to comprehensively investigate the epidemiology and clinical outcomes of cardiac arrhythmias in patients with PAH.

Methods: In a retrospective cohort study including 512 PAH patients from 2001-2021 at 3 Mayo Clinic sites, PAH patients were identified via echocardiogram, pulmonary function tests, and right heart catheterization. Demographic data at PAH diagnosis and clinical outcomes over a 10-year period were collected. The PAH patients were categorized into three groups based on arrhythmic onset: 1) patients with arrhythmia prior to PAH diagnosis, 2) patients diagnosed with arrhythmia during 10-year PAH follow-up, and 3) patients without arrhythmia during 10-year PAH follow-up. Survival outcomes were analyzed using multivariable Cox proportional hazards regression, adjusted with the REVEAL 2.0 score.

Results: Among 512 PAH patients (mean age 56.1 years, 81.8% female), the prevalence of cardiac arrhythmias at PAH diagnosis was 10.5%. The cumulative incidences of new-onset arrhythmias at 1, 5, and 10 years were 6.6%, 18.4%, and 29.2%, respectively. Patients with arrhythmia diagnosed before and after PAH diagnosis showed significantly higher all-cause mortality rates with adjusted HR of 2.06 [95% CI 1.36-3.12] and 1.57 [95% CI 1.17-2.20] respectively (Figure 1). Similarly in both arrhythmic groups, there was a shorter median time to the first all-cause hospitalization (9.5 and 15.9 months vs. 21.2 months) and a higher number of all-cause hospitalizations (0.38 and 0.64 times per year vs. 0.10 times per year) compared to the non-arrhythmic group.

Conclusions: Cardiac arrhythmias can develop in nearly one-third of PAH patients within 10 years of PAH diagnosis and independently contribute to increased mortality and hospitalization frequency.