0110: Exercise stress echocardiography in secondary mitral regurgitation: impact of pulmonary hypertension

Abstract

Secondary mitral regurgitation (MR) is a serious and frequent complication of dilated cardiomyopathy and/or coronary artery disease. The impact of exerxise pulmonary hypertension (ExPHT) on outcome in patients with secondary MR is unknown. All patients with secondary MR, sinus rhythms, narrow QRS (<120ms) and referred for exercise stress echocardiography with quantifiable exercise systolic pulmonary arterial pressure (SPAP), were included in this study (n=159, 65±11 years, 66% of male). Resting and ExPHT were defined as a systolic pulmonary arterial pressure (SPAP) >50mmHg and >60mmHg, respectively. ExPHT was more frequent than resting PHT (40% vs. 13%, p<0.0001). There was no significant difference between patients with or without ExPHT regarding demographic and clinical data, as well as medication. Using multiple linear regression, exercise SPAP was determined by resting SPAP (β=0.94±0.1, p<0.0001), exercise MR severity (β=0.58±0.1, p<0.0001), and resting e’-wave velocity (β=–1.3±0.4, p=0.004). During a mean follow-up of 35±11 months, 60 major adverse cardiovascular events occured. The incidence of combined cardiac event was significantly higher in patients with ExPHT as compared to those without ExPHT (2-year: 11±3 vs. 28±6%; 4-year: 20±5 vs. 40±7%, p<0.0001). Similarly, patients with ExPHT demonstrated significantly reduced survival (2-year: 88±4 vs. 99±1%; 4-year: 62±8% vs. 94±2%, p<0.0001). In multivariate Cox proportional Hazard model, after adjustment for age, sex, left ventricular volumes, both resting and exercise diastolic function and resting MR severity, ExPHT remains significantly associated with high risk of combined cardiac event (Hazard ratio=3.7, 95% of CI: 1.9-7.2, p<0.0001). In patients with secondary MR, ExPHT may be frequent and mainly determined by resting SPAP, LV diastolic burden markers and exercise MR severity. ExPHT is a powerful predictor of poor outcome and is associated with a 3.7-fold increase in risk of cardiac event. These results further highlight the usefulness of exercise stress echocardiography for the management and the risk stratification of these patients.