Supplementary Material for: Prognostic Impact of the Pulmonary Artery Pulsatility Index in Patients with Chronic Heart Failure and Severe Mitral Regurgitation Undergoing Percutaneous Edge-to-Edge Repair

<b><i>Background:</i></b> Pulmonary artery (PA) pulsatility index (PAPi), calculated as (PA systolic pressure – PA diastolic pressure)/right atrial pressure, emerged as a novel predictor of right ventricular failure in patients with acute inferior myocardial infarction, advanced heart failure, and severe pulmonary hypertension. However, the prognostic utility of PAPi in transcatheter mitral valve repair (TMVR) using the MitraClip® system has never been tested. <b><i>Objective:</i></b> To assess the prognostic impact of PAPi in patients with severe functional mitral regurgitation (MR) and chronic heart failure (CHF) undergoing TMVR. <b><i>Methods:</i></b> Consecutive patients with severe functional MR (grade 3+ or 4+) and CHF who underwent successful TMVR (MR ≤2+ at discharge) were enrolled and divided into 3 groups according to PAPi (A: low PAPi ≤2.2; B: intermediate PAPi 2.21–3.99; C: high PAPi ≥4.0). The primary endpoint was a composite of all-cause mortality and rehospitalization due to CHF during a mean follow-up period of 16 ± 4 months. The impact of PAPi on prognosis was assessed by a receiver-operating characteristic (ROC) analysis and a multivariable Cox proportional hazard regression analysis investigating independent predictors for outcome. <b><i>Results:</i></b> 78 patients (A: <i>n</i> = 27, B: <i>n</i> = 28, C: <i>n</i> = 23) at high operative risk (logistic EuroSCORE [European System for Cardiac Operative Risk Evaluation] 18.8 vs. 21.5 vs. 20.6%; nonsignificant) were enrolled. Mean PAPi was 1.6 ± 0.41 vs. 2.9 ± 0.53 vs. 6.8 ± 3.5; <i>p</i> &lt; 0.001). Patients with low PAPi showed significantly higher rates of early rehospitalization for heart failure at the 30-day follow-up (14.9 vs. 7.1 vs. 4.3%; <i>p</i> = 0.04). In the long term, a significantly lower event-free survival for the combined primary endpoint was observed in the low PAPi group (44.4 vs. 25.0 vs. 20.3%; log-rank <i>p</i> = 0.016). ROC curve analysis revealed that optimal sensitivity and specificity were achieved using a PAPi cutoff of 2.46 (sensitivity 83%, specificity 78.3%, area under the curve 0.82 [0.64–0.99]; <i>p</i> = 0.01). In Cox regression analysis, PAPi ≤2.46 was an independent predictor for the combined primary endpoint (hazard ratio 2.85; 95% confidence interval 1.15–7.04; <i>p</i> = 0.023). <b><i>Conclusions:</i></b> PAPi is strongly associated with clinical outcome among patients with CHF and functional MR undergoing TMVR. A PAPi value ≤2.46 predicts a worse prognosis independent of other important clinical, echocardiographic, and hemodynamic factors. Therefore, PAPi may serve as a new parameter to improve patient selection for TMVR.

**背景：** 肺动脉（Pulmonary Artery, PA）搏动指数（Pulsatility Index, PAPi），计算公式为（肺动脉收缩压−肺动脉舒张压）/右心房压，最初被证实可作为急性下壁心肌梗死、晚期心力衰竭及重度肺动脉高压患者右心室衰竭的新型预测因子。然而，目前尚无研究评估PAPi在采用MitraClip®系统行经导管二尖瓣修复术（Transcatheter Mitral Valve Repair, TMVR）中的预后应用价值。
**目的：** 评估PAPi对接受TMVR的重度功能性二尖瓣反流（Mitral Regurgitation, MR）及慢性心力衰竭（Chronic Heart Failure, CHF）患者的预后影响。
**方法：** 纳入符合入组标准的重度功能性MR（3+级或4+级）合并CHF且成功接受TMVR（出院时MR≤2+）的连续患者，依据PAPi水平分为3组：A组（低PAPi组：PAPi≤2.2）、B组（中PAPi组：2.21~3.99）、C组（高PAPi组：PAPi≥4.0）。本研究的主要终点为平均随访16±4个月期间的全因死亡及因CHF再住院的复合终点。采用受试者工作特征（Receiver-Operating Characteristic, ROC）曲线分析及多变量Cox比例风险回归分析，以评估PAPi对预后的影响，并明确预后的独立预测因子。
**结果：** 共纳入78例高危手术风险患者（A组n=27、B组n=28、C组n=23），三组的logistic EuroSCORE（欧洲心脏手术风险评估系统，European System for Cardiac Operative Risk Evaluation）分别为18.8%、21.5%、20.6%，组间差异无统计学意义。三组的平均PAPi分别为1.6±0.41、2.9±0.53及6.8±3.5（p<0.001）。低PAPi组患者在30天随访时的早期心力衰竭再住院率显著更高（14.9% vs. 7.1% vs. 4.3%；p=0.04）。长期随访中，低PAPi组的主要复合终点无事件生存率显著更低（44.4% vs. 25.0% vs. 20.3%；log-rank检验p=0.016）。ROC曲线分析显示，当PAPi截断值为2.46时，可获得最优的灵敏度与特异度：灵敏度83%，特异度78.3%，曲线下面积为0.82（95%置信区间0.64~0.99；p=0.01）。Cox回归分析显示，PAPi≤2.46是主要复合终点的独立预测因子（风险比2.85；95%置信区间1.15~7.04；p=0.023）。
**结论：** 在接受TMVR的CHF合并功能性MR患者中，PAPi与临床预后显著相关。PAPi≤2.46可独立于其他重要临床、超声心动图及血流动力学因素，预测不良预后。因此，PAPi可作为改善TMVR患者筛选的新型参数。