Supplementary Material for: Impact of Pulmonary Hypertension Hemodynamic Phenotype on Incident Atrial Fibrillation

Introduction: Atrial fibrillation/flutter (AF) is common among patients with pulmonary hypertension (PH) and is associated with poor clinical outcomes. AF has been shown to occur more commonly among patients with post-capillary PH, although AF also occurs among patients with pre-capillary PH. The goal of this study was to evaluate the independent impact of PH hemodynamic phenotype on incident AF among patients with PH. Methods: We retrospectively identified 262 consecutive patients, without a prior diagnosis of atrial arrhythmias, seen at the PH clinic at Mayo Clinic, Florida, between 1997 and 2017, who had right heart catheterization (RHC) and echocardiography performed, with follow-up for outcomes through 2021. Kaplan-Meier analysis and Cox-proportional hazards regression modeling were used to evaluate the independent effect of PH hemodynamic phenotype on incident AF. Results: Our study population was classified into two broad PH hemodynamic groups: pre-capillary (64.9%) and post-capillary (35.1%). The median age was 59.5 years (Q1: 48.4, Q3: 68.4), and 72% were female. In crude models, post-capillary PH was significantly associated with incident AF (HR 2.17, 95% CI: 1.26 – 3.74, p=0.005). This association was lost following multivariable adjustment, whereas left atrial volume index remained independently associated with incident AF (aHR 1.30, 95% CI: 1.09 – 1.54, p=0.003). Conclusion: We found PH hemodynamic phenotype was not significantly associated with incident AF in our patient sample, however, echocardiographic evidence of left atrial remodeling appeared to have a greater impact on AF development. Larger studies are needed to validate these findings and identify potential modifiable risk factors for AF in this population.