Abstract 4139227: Exercise Right Ventricular-Pulmonary Arterial Coupling predicts long-term Functional Outcome in Patients undergoing Surgery for Secondary Ischemic Mitral Regurgitation.

Background: The treatment of secondary ischemic mitral regurgitation is challenging and predictors of functional and clinical outcome are pivotal in order to define the best therapeutic strategy. In these patients there is growing evidence that assessing the right ventricular (RV)-pulmonary arterial (PA) coupling during exercise has additive diagnostic and prognostic value. To date, no data are available as regard the exercise assessment of the RV- PA coupling in patients undergoing surgery for ischemic mitral regurgitation Research Question: in patients with ischemic mitral regurgitation the evaluation of the exercise RV-PA coupling could play a crucial role for patients selection and prognosis Aim: to test resting and exercise echocardiographic predictors of functional capacity and clinical outcome in patients referred to surgery Methods: A 6-minute walking test and exercise stress echo performed at preoperative baseline, at 1 year and at median FU of 6 years (IQR: 3.70; range: 4.5– 8) on 50 patients (age: 67 ± 8 year; EF: 35 ± 5%), undergoing surgery by valve replacement or repair. Generalized linear mixed models were used to evaluate the predictive value of preoperative echocardiographic parameters on the longitudinal distribution of the 6-MWT. Results: Preoperative exercise tricuspid annular plane systolic excursion (TAPSE)/ pulmonary artery systolic pressure (PASP) ratio showed the strongest correlation with long-term six-minute walking test (r=0.81, p< 0.01) (Figure 1).The receiver operating characteristic analysis found that a preoperative exercise TAPSE/PASP < 0.34 predicted the lowest quartile of six-minute walking test at long-term (sensitivity: 79%; specificity: 100%) (Figure 2) and a composite clinical outcome of heart failure and death for any cause (PPV 91.3%, NPV 100%). On multivariable analysis TAPSE (Estimates:4.05; SE:0.90; p < 0.01) and TAPSE/PASP ratio (Estimates:106.9; SE: 31.54, p <0.01) were significantly associated with better long-term six-minute walking test (Table 1) Conclusions: A preoperative exercise TAPSE/PAPS < 0.34 predicts a poor six-minute walking test performance and an higher likelihood of clinical adverse events over time. In patients with secondary ischemic mitral regurgitation the exercise RV-PA coupling could add value in order to improve risk stratification. These findings need to be comfirmed by larger studies