Prognostic implication of right ventricular - pulmonary arterial coupling in patients with non-valvular atrial fibrillation

Abstract Background The clinical importance of right ventricular (RV) - pulmonary arterial (PA) coupling has been reported in various cardiac diseases such as right heart failure, pulmonary hypertension, and valvular dysfunction. However, there is limited data on patients with non-valvular atrial fibrillation (AF). We aim to investigate whether RV-PA uncoupling affects the clinical outcome in patients with non-valvular AF. Methods A total of 807 consecutive patients with non-valvular AF who underwent echocardiography (mean age 70 ± 12 years, 39% female) were included. We excluded patients with significant (at least moderate degree) valvular diseases, left ventricular ejection fraction (LVEF) <50%, cardiac implantable electronic devices, previous cardiac surgery, and poor echocardiographic image for RV analysis. RV-PA coupling was assessed by the ratio of RV global longitudinal strain (GLS) to PA systolic pressure (PASP), and decreased RV-PA coupling was defined as less than 0.52 %/mmHg based on on the receiver operating characteristic analysis. The primary outcome was the composite of all-cause death and hospitalization for heart failure. Results Over a mean of 4.7 ± 3.5 years of follow-up, 178 (22%) patients had experienced primary outcomes. Among them, 107 (13%) patients were hospitalized for HF and 90 (11%) patients died. Patients with decreased RV-PA coupling were older (73 ± 11 vs. 68 ± 12 years, p<0.001), had a higher prevalence of females (51 vs. 33%, p<0.001) and diabetes (33 vs. 23%, p=0.003), lower left ventricular ejection fraction (60 ± 5 vs. 61 ± 5%, p=0.011), higher E/e’ (14 ± 5 vs. 11 ± 4, p<0.001), larger left atrial volume index (78 ± 37 vs. 62 ± 22 ml/m2, p<0.001) and larger RV end-systolic area (11 ± 4 vs. 10 ± 3 cm2/m2, p=0.001) compared to those with preserved RV-PA coupling. In multivariate Cox regression analysis, decreased RV-PA coupling was associated with worse clinical outcomes even after adjusting for age, diabetes, E/e’, and RV end-systolic area (Hazard ratio [HR] 1.50, 95% Confidence interval [CI] 1.09 – 2.07, p=0.014) (Figure 1). Conclusions In patients with non-valvular AF, RV-PA coupling was associated with clinical outcome, suggesting that it may provide additional information for predicting future cardiovascular risk in this population.