Acute changes in mitral valve geometry after percutaneous valve repair with MitraClip XTR by three-dimensional echocardiography

Short-Term Effects of Different Transcatheter Edge-to-Edge Devices on Mitral Valve Geometry

Background Short-term effects on mitral valve (MV) anatomy after transcatheter edge-to-edge repair using the PASCAL system remain unknown. Precise quantification might allow for an advanced analysis of predictors for mean transmitral gradients. Methods and Results Consecutive patients undergoing transcatheter edge-to-edge repair for secondary mitral regurgitation using PASCAL or MitraClip systems were included. Quantification of short-term MV changes throughout the cardiac cycle was performed using peri-interventional 3-dimensional MV images. Predictors for mean transmitral gradients were identified in univariable and multivariable regression analysis. Long-term results were described during 1-year follow-up. A total of 100 patients undergoing transcatheter edge-to-edge repair using PASCAL (n=50) or MitraClip systems (n=50) were included. Significant reductions of anterior-posterior diameter, annular circumference, and area throughout the cardiac cycle were found in both cohorts (P<0.05 for all). Anatomic MV orifice area remained larger in the PASCAL cohort in mid (2.8±1.0 versus 2.4±0.9 cm2; P=0.049) and late diastole (2.7±1.1 versus 2.2±0.8 cm2; P=0.036) compared with the MitraClip cohort. Besides a device-specific profile of independent predictor of mean transmitral gradients, reduction of middiastolic anatomic MV orifice area was identified as an independent predictor in both the PASCAL (β=-0.410; P=0.001) and MitraClip cohorts (β=-0.318; P=0.028). At follow-up, reduction of mitral regurgitation grade to mild or less was more durable in the PASCAL cohort (90% versus 72%; P=0.035). Conclusions PASCAL and MitraClip showed comparable short-term effects on MV geometry. However, PASCAL might better preserve MV function and demonstrated more durable mitral regurgitation reduction during follow-up. Identification of independent predictors for mean transmitral gradients might potentially help to guide device selection in the future.

Dynamic Secondary Mitral Regurgitation: Current Evidence and Challenges for the Future

Heart failure (HF) is a challenging situation in healthcare worldwide. Secondary mitral regurgitation (SMR) is a common condition in HF patients with reduced ejection fraction (HFrEF) and tends to be increasingly associated with unfavorable clinical outcomes as the severity of SMR increases. It is worth noting that SMR can deteriorate dynamically under stress. Over the past three decades, the characteristics of dynamic SMR have been studied. Dynamic SMR contributes to the reduction in exercise capacity and adverse clinical outcomes. Current guidelines refer to the indication of transcatheter edge-to-edge repair (TEER) for significant SMR based on data from the Cardiovascular Outcomes Assessment of the MitraClip Percutaneous Therapy for Heart Failure Patients with Functional Mitral Regurgitation (COAPT) trial if symptomatic despite optimal guideline-directed medical therapy (GDMT) and cardiac resynchronization therapy (CRT), but nonpharmacological treatment for dynamic SMR remains challenging. In HFrEF patients with LV dyssynchrony and dynamic SMR, CRT can improve LV dyssynchrony and subsequently attenuate SMR at rest and during exercise. Also, a recent study suggests that TEER with GDMT and CRT is more effective in symptomatic patients with HFrEF and dynamic SMR than GDMT and CRT alone. Further studies are needed to evaluate the safety and efficacy of nonpharmacological treatments for dynamic SMR. In this review, current evidence and challenges for the future of dynamic SMR are discussed.