De Novo Atrial Fibrillation on pV-A ECMO Fibrillation Portends Higher Post-Decannulation Mortality

<h2>Abstract</h2><h3>Introduction</h3> Peripheral veno-arterial extracorporeal membrane oxygenation (pV-A ECMO) is being used with increased frequency to support patients with cardiogenic shock (CS). While de novo atrial fibrillation (dnAF) is associated with poor outcomes in veno-venous ECMO, its impact in pV-A ECMO remains unclear. We hypothesized that elevated pulmonary artery diastolic pressure (PADP) is associated with a higher incidence of dnAF and worse in-hospital outcomes. <h3>Methods</h3> We retrospectively reviewed patients ≥ 18 years supported with pV-A ECMO at a single center from 2011–2023, excluding those with preexisting AF and/or significant mitral valve disease. The association between PADP and dnAF incidence, and the effect of dnAF on in-hospital mortality, were analyzed. Secondary outcomes included survival to decannulation and duration of support. Multivariable Cox regression, adjusted for the competing risk of death, estimated the hazard ratio of dnAF based on PADP. <h3>Results</h3> Of 340 patients, 68 (20%) developed dnAF and 272 (80%) remained in sinus rhythm (SR). The cohort was predominantly male (n = 214, 63%) and white (n = 298, 88%), with comorbidities including heart failure (n = 162, 48%) and hypertension (n = 236, 70%). Indications for pV-A ECMO were CS (n = 237, 70%) and extracorporeal cardiopulmonary resuscitation (n = 103, 30%). Vasoactive inotrope scores were similar between groups. De novo AF while on pV-A ECMO was associated with longer ECMO duration (6.4 vs 3.6 days; <i>P</i> < 0.001) and higher postdecannulation in-hospital mortality (n = 22/68; 33% vs n = 55/272, 20%; <i>P</i> = 0.049). Survival to decannulation was similar (n = 55/68, 81% vs n = 217/272, 80%; <i>P</i> = 0.8). PADP elevations were linked to a nonsignificantly increased dnAF risk (HR 1.03 for each 1 mmHg increase in PADP; 95% CI: 1.00–1.07; <i>P</i> = 0.1). <h3>Conclusion</h3> De novo AF occurring while on pV-A ECMO is associated with higher postdecannulation in-hospital mortality rates and longer duration of pV-A ECMO relative to patients who maintained SR. PADP elevations trended toward a higher incidence of dnAF, though statistical significance was not met. Further investigations are needed to identify ways to decrease the dnAF burden and impact in this cohort of patients.