Prognostic value of pulmonary artery pulsatility index for perioperative adverse cardiovascular events in patients undergoing surgery for mitral regurgitation

Abstract

Background The pulmonary artery pulsatility index (PAPi) demonstrates prognostic value across cardiopulmonary conditions, yet its utility in mitral regurgitation (MR) perioperative risk stratification remains undefined. This study aimed to evaluate whether the PAPi could independently predict perioperative adverse cardiovascular events in patients with MR, and to explore whether its addition to the European System for Cardiac Operative Risk Evaluation (EuroSCORE) II provided incremental value. Methods This ambidirectional cohort study enrolled 302 consecutive patients with moderate-to-severe MR undergoing mitral valve surgery. PAPi was calculated as pulmonary artery pulse pressure (pulmonary artery systolic pressure minus diastolic pressure) divided by right atrial pressure, all estimated by echocardiography. Patients were grouped by PAPi tertiles and followed for 3 months. The primary endpoint was major adverse cardiovascular events (MACEs). Exploratory endpoints included mechanical ventilation duration and inotropic support. Incremental value was assessed by integrating PAPi into EuroSCORE II. Results Patients were stratified into low PAPi (<3.4, n=99), intermediate PAPi (3.4–4.8, n=101), and high PAPi (>4.8, n=102) groups. MACE incidence was 37.4% (37/99), 10.9% (11/101), and 3.9% (4/102), respectively (χ2=43.70, P<0.001). Lower PAPi was associated with prolonged mechanical ventilation, inotropic support, and intensive care unit (ICU) stay (all P<0.001). Receiver operating characteristic (ROC) analysis showed that PAPi predicted MACE with an area under the curve (AUC) of 0.82 [95% confidence interval (CI): 0.76–0.88]. At cutoff 3.45, sensitivity was 81%, specificity 75%, positive predictive value (PPV) 40.0%, and negative predictive value (NPV) 94.9%. Bootstrap validation confirmed stability (AUC 0.82, 95% CI: 0.761–0.878). Multivariate analysis identified PAPi [odds ratio (OR) =0.26, 95% CI: 0.15–0.45, P<0.001], EuroSCORE II (OR=1.15, 95% CI: 1.03–1.28, P=0.012), and tricuspid annular plane systolicexcursion/pulmonary artery systolic pressure [TAPSE/PASP; OR =0.79 per 1-standard deviation (SD) decrease, 95% CI: 0.65–0.95, P=0.013] as independent predictors. Each 1-unit PAPi decrease was associated with a 3.8-fold increase in MACE risk. Adding PAPi to clinical risk score and echocardiographic right ventricular function models improved predictive performance [C-statistic 0.70 to 0.85; net reclassification improvement (NRI) =0.807; integrated discrimination improvement (IDI) =0.144; all P<0.001]. Bootstrap optimism correction yielded an AUC of 0.85 (95% CI: 0.80–0.90). Subgroup analyses showed consistent predictive value (all interaction P>0.05). Conclusions The echocardiography-derived PAPi predicts perioperative MACE in patients with MR. Incorporation of this index into traditional risk scoring systems provides incremental value for preoperative risk assessment and facilitates the identification of high-risk patients.