Noninvasive Myocardial Work Predicts Long-Term Postinterventional Outcomes in Patients With Primary Mitral Regurgitation.

BACKGROUND

Accurate and early identification of impaired left ventricular (LV) function is essential to the optimal timing of intervention for primary mitral regurgitation. Myocardial work derived from noninvasive pressure-strain loop is a novel and promising afterload-independent approach to evaluate LV performance. We hypothesized that it may provide diagnostic and prognostic utility in these patients. This study aimed to evaluate myocardial work parameters in patients with significant primary mitral regurgitation, and explore their association with postinterventional LV ejection fraction and clinical composite events.

METHODS

The study prospectively enrolled 180 patients with severe primary mitral regurgitation at baseline and patients were followed up for postinterventional LV function (>12 months) and clinical events (24.0 [23.3-24.6] months). Logistic regression and Cox proportional hazards regression analyses were performed as appropriate.

RESULTS

Compared with patients exhibiting postinterventional LV ejection fraction ≥50%, individuals with LV ejection fraction <50% demonstrated lower LV global longitudinal strain, global work index (GWI), global constructive work (GCW), and global work efficiency (P<0.001 for all) and higher global wasted work (P=0.001). Preinterventional LV global longitudinal strain, GWI, GCW, and global work efficiency were independent predictors of postinterventional LV dysfunction (P<0.05 for all). The predictive power of logistic regression models comprising LV global longitudinal strain, GWI, and GCW were similar but stronger than the model comprising LV ejection fraction. Preinterventional LV global longitudinal strain, GWI, GCW, and global work efficiency were independently associated with the risk of composite clinical events during follow-up (P<0.001 for all).

CONCLUSIONS

Myocardial work parameters, especially GWI, GCW, and global work efficiency, are independent predictors of postinterventional LV dysfunction and are associated with the occurrence of postinterventional clinical composite events.