Right ventricular to pulmonary artery coupling and clinical outcomes after interatrial shunting in heart failure

Background Left atrial decompression is under investigation for heart failure (HF) with the potential to improve symptoms and potentially clinical outcomes. However, heterogeneous outcomes have been observed in randomized controlled studies. Purpose This study aimed to explore whether right ventricular (RV) -pulmonary artery (PA) coupling, as assessed from the tricuspid annular plane systolic excursion (TAPSE) /systolic PA pressure ratio, can be useful in predicting outcomes after implantation of the interatrial shunting device. Methods A total of 106 HF patients, n=62 with reduced ejection fraction (HFrEF), n=44 with preserved ejection fraction (HFpEF), were prospectively enrolled in the PRELIEVE registry with the Atrial Flow Regulator (AFR) implantation. Clinical outcomes included cardiovascular (CV) mortality and HF worsening. RV-PA coupling was associated from the TAPSE/pulmonary artery systolic pressure (PASP) ratio. Results CV death or HF worsening occurred in a total of 19 (18%) patients. In the entire cohort at baseline, patients with either event showed lower noninvasive or invasive TAPSE/PASP ratio (0.53, IQR 0.43, 0.76 vs 0.43, IQR 0.33, 0.53, p=0.04 and 0.48 IQR 0.38, 0.66 vs 0.38, IQR 0.25, 0.61, p=0.02) and NT-pro-BNP (317, IQR 114, 1200, vs 1261, IQR 567, 1790 pg/mL, p=0.01). No other significant differences were observed; of note, proportion of patients with either 8mm or 10mm shunt size was similar between both groups (Table). Incidence of outcomes was higher in patients within the first vs the third TAPSE/PASP tertile (59% vs 12%, p=0.026), respectively. In the subgroup analysis, HFrEF as well as HFpEF patients showed also reduced RV-PA coupling at baseline with higher incidence of events at lowest tertile. A TAPSE/PASP of <0.55 was identified to bear the optimal sensitivity to predict the event (AUC 0.634, 95%CI 0.48, 0.78). Conclusion The reduced TAPSE/PASP ratio was associated with higher rates of CV mortality or HF worsening in patients with heart failure of either phenotype undergoing controlled inter-atrial shunting. The hypothesis generating finding that reduced RV-PA coupling may identify potential clinical non-responders to left atrial decompression should be further validated prospectively.