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

Figures

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  Figure 1. Echocardiographic images of severe MR caused by prolapse. (A) Parasternal long-axis view; (B) short-axis view (the arrow indicates mitral valve leaflet prolapse). MR, mitral regurgitation.

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  Figure 2. Patient screening flowchart. CABG, coronary artery bypass grafting; MR, mitral regurgitation; PAPi, pulmonary artery pulsatility index.

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  Figure 3. Echocardiographic measurement methods for right heart parameters. (A) Tricuspid regurgitation velocity and pressure gradient measured using continuous-wave Doppler; (B) pulmonary valve end-diastolic regurgitation velocity and pressure gradient measured using continuous-wave Doppler; (C) inferior vena cava diameter and inspiratory collapse rate; (D) TAPSE measurement; (E) FAC measurement. RV EDA, right ventricular end-diastolic area; RV FAC, right ventricular fractional area change; TAPSE, tricuspid annular plane systolic excursion.

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  Figure 4. Kaplan-Meier curves for MACE-free survival across three PAPi groups. Group 1 represents the low PAPi group (<3.4), Group 2 the intermediate PAPi group (3.4–4.8), and Group 3 the high PAPi group (>4.8). MACE-free survival was significantly lower in the low PAPi group compared with both the intermediate and high PAPi groups (log-rank P<0.001). MACE, major adverse cardiovascular event; PAPi, pulmonary artery pulsatility index.

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  Figure 5. ROC curves of various indices for predicting MACE. AUC, area under the curve; FAC, right ventricular fractional area change; LVEF, left ventricular ejection fraction; MACE, major adverse cardiovascular event; PAPi, pulmonary artery pulsatility index; ROC, receiver operating characteristic; TAPSE, tricuspid annular plane systolic excursion; TAPSE/PASP, tricuspid annular plane systolic excursion/pulmonary artery systolic pressure.

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  Figure 6. Subgroup analysis of PAPi for predicting MACE. All interaction P values were >0.05, suggesting consistent predictive value of PAPi across subgroups. CI, confidence interval; FAC, fractional area change; MACE, major adverse cardiovascular event; OP, operative procedure; OR, odds ratio; PAPi, pulmonary artery pulsatility index; TR, tricuspid regurgitation; TVP, tricuspid valvuloplasty.

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  Figure 7. Comparison of three risk prediction models. (A) ROC curves for the three models. (B) AUC values for the three models. (C) Heatmap of model performance metrics. Model 3 demonstrated the highest AUC value, indicating that the incorporation of PAPi significantly improved the predictive performance of the model. Model 1: EuroSCORE II; Model 2: EuroSCORE II with the addition of TAPSE/PASP; Model 3: Model 2 with the addition of PAPi. AIC, Akaike information criterion; AUC, area under the curve; BIC, Bayesian information criterion; EuroSCORE, European System for Cardiac Operative Risk Evaluation; PAPi, pulmonary artery pulsatility index; ROC, receiver operating characteristic; TAPSE/PASP, tricuspid annular plane systolic excursion/pulmonary artery systolic pressure.

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  Figure 8. Nomogram, calibration, and decision curve analysis based on the optimal model. (A) Nomogram for predicting probability. PAPi contributed the highest score weight; (B) calibration curve showing close approximation between predicted and observed probabilities across all risk strata; (C) decision curve showing positive net benefit across threshold probabilities of 0.1–0.8, with optimal net benefit (0.08–0.12) at 0.05–0.20 thresholds. AUC, area under the curve; EuroSCORE, European System for Cardiac Operative Risk Evaluation; PAPi, pulmonary artery pulsatility index; TAPSE/PASP, tricuspid annular plane systolic excursion/pulmonary artery systolic pressure.