Mitral Valve Prolapse with Mid-Late Systolic Mitral Regurgitation: Pitfalls of Evaluation and Clinical Outcome Compared to Holosystolic Regurgitation
Background—Mitral regurgitation (MR) of mitral valve prolapse (MVP) predominates in late-systole but may be holosystolic (Holo-MR) or purely mid-late systolic (Mid-Late-MR) but the impact of MR-timing on MR left ventricular (LV) atrial (LA) consequences and outcome is unknown. Whether effective-regurgitant-orifice (ERO) by flow-convergence method is similarly linked to outcome in Mid-Late-MR and Holo-MR is uncertain.
Methods and Results—We comprehensively and prospectively quantified MR in 111 patients with MVP and Mid-Late-MR and matched them to 90 patients with MVP and Holo-MR for age, gender, atrial fibrillation, ejection fraction and ERO (flow-convergence). Mid-Late-MR vs. Holo-MR groups were well-matched including for comorbidity, blood pressure and heart rate (all p>0.10). Mid-Late-MR vs. Holo-MR caused similar color jet-area, mid-systolic regurgitant flow and peak velocity (p>0.40). Despite identical ERO (0.25±0.15 vs.0.25±0.15 cm2, p=0.53), Mid-Late-MR shorter duration (233±56 vs. 426±50 msec, p<0.0001) yielded lower regurgitant volume (24.8±13.4 vs. 48.6±25.6mL; p<0.0001). MR consequences, systolic pulmonary pressure, LV and LA-volume-index (all p<0.001) were more benign in Mid-Late-MR vs. Holo-MR. Under medical management less cardiac events (5-year 15.8±4.6 vs. 40.4±6.1%, p<0.0001) occurred in Mid-Late-MR vs. Holo-MR requiring less mitral surgery. Multivariable analysis confirmed the independent association of Mid-Late-MR with benign consequences and outcomes (all p<0.01). Absolute ERO was not linked to outcome in contrast to regurgitant volume.
Conclusions—MR of MVP purely Mid-Late systolic causes more benign consequences and outcomes than holosystolic MR. Assessment may be misleading as jet area and ERO by flow-convergence appear similar to holosystolic MR. However, shorter MR yields lower RVol, consequences and benign outcomes. Instantaneous ERO by flow-convergence should be interpreted in context and in Mid-Late-MR regurgitant volume provides information more reflective of MR severity. Therefore, clinical management and surgical referral should carefully take into account timing and consequences of MR.
- Received July 11, 2011.
- Accepted February 22, 2012.
- Copyright © 2012, American Heart Association, Inc. All rights reserved. Unauthorized use prohibited