Abstract 10666: Prognostic Significance of Exercise Induced Right Ventricular Dysfunction in Asymptomatic Degenerative Mitral Regurgitation

Abstract

Background. Exercise-induced pulmonary hypertension (exPH) has recently been removed from operative guidelines for asymptomatic degenerative mitral regurgitation (MR) because of variability of responses. We reasoned that the exPH response could not be interpreted without knowledge of right ventricular (RV) function. The aim of study was to assess the rule of RV measures as predictors of prognosis in asymptomatic degenerative MR.

Methods. Comprehensive resting and exercise echo was performed in 196 consecutive pts (56±13y; 64% men) with isolated moderate to severe MR (effective regurgitant orifice area 38±18 mm²; regurgitant volume = 61±27 ml) and preserved left ventricular (LV) function in whom initial management was expectant. LV and RV longitudinal strain were analyzed at rest using velocity vector imaging. Tricuspid annular plane systolic excursion (TAPSE) and systolic pulmonary arterial pressure (SPAP) were measured at rest and exercise.

Results. Valve surgery was performed in 88 pts (45%) over 27±15m. In Cox multivariable analysis, TAPSE at exercise (HR=0.34, p<0.001) was independent of LV strain (HR=1.10, p=0.01), SPAP at exercise (HR=1.03, p=0.001) as independent correlates of event-free survival. In sequential Cox models, a model based on clinical data and LV strain (chi-square, 12.1) was improved by RV strain (chi-square, 17.5, p=0.022) or SPAP at exercise (chi-square, 28.9, p<0.001) and further increased by TAPSE at exercise (chi-square, 45.7, p<0.001) (left figure). Exercise TAPSE <2.0cm (median) was associated with significantly reduced event-free survival (right figure).

Conclusions. In asymptomatic degenerative MR, LV and RV strain at rest, TAPSE and SPAP at exercise were independently associated with surgery during follow-up.