Percutaneous mitral valve repair with MitraClip increased median end-systolic wall stress from 184 to 209 mm Hg (P=0.001) and decreased end-diastolic wall stress from 48 to 34 mm Hg (P=0.005).
Observational (n=33)
Absolute Event Rate: 209% vs 184%
p-value: p=0.001
BACKGROUND: Percutaneous mitral valve repair with the MitraClip device has emerged as an alternative to surgery for treating severe mitral regurgitation. However, its effects on left ventricular loading conditions and contractility have not been investigated yet. METHODS AND RESULTS: Pressure-volume loops were recorded throughout the MitraClip procedure using conductance catheter in 33 patients (mean age, 78±10 years) with functional (45%), degenerative (48%), or mixed (6%) mitral regurgitation. Percutaneous mitral valve repair increased end-systolic wall stress (WSES; from median 184 mm Hg interquartile range (IQR), 140-200 mm Hg to 209 mm Hg IQR, 176-232 mm Hg; P=0.001) and decreased end-diastolic WS (WSED; from 48 mm Hg IQR, 28-58 mm Hg to 34 mm Hg IQR, 21-46 mm Hg; P=0.005), whereas the end-systolic pressure-volume relationship was not significantly affected. Conversely, cardiac index increased (from 2.6 L·min(-1)·m(-2) IQR, 2.2-3.0 L·min(-1)·m(-2) to 3.2 L·min(-1)·m(-2) IQR, 2.6-3.8 L·min(-1)·m(-2); P<0.001) and mean pulmonary capillary wedge pressure decreased (from 15 mm Hg IQR, 12-20 mm Hg to 12 mm Hg IQR, 10-13 mm Hg; P<0.001). Although changes in WSES were not correlated with changes in cardiac index, changes in WSED correlated significantly with changes in mean pulmonary capillary wedge pressure (r=0.63, P<0.001). Total mechanical energy assessed by the pressure-volume area remained unchanged, resulting in a more favorable index of forward output (cardiac index) to mechanical energy (pressure-volume area) after mitral valve repair. On follow-up (153±94 days), New York Heart Association functional class was reduced from 2.9±0.6 to 1.9±0.5 (P<0.001) at 3 months, and echocardiographic follow-up documented a stepwise reduction in end-diastolic volume (from 147 mL IQR, 95-191 mL to 127 mL IQR, 82-202 mL; P=0.036). CONCLUSIONS: Percutaneous mitral valve repair improves hemodynamic profiles and induces reverse left ventricular remodeling by reducing left ventricular preload while preserving contractility. In nonsurgical candidates with compromised left ventricular function, MitraClip therapy could be considered an alternative to surgical mitral valve repair.
Gaemperli et al. (Sat,) conducted a observational in Severe mitral regurgitation (n=33). Percutaneous mitral valve repair with the MitraClip system vs. Baseline (pre-procedure) was evaluated on End-systolic wall stress (WSES) (p=0.001). Percutaneous mitral valve repair with MitraClip increased median end-systolic wall stress from 184 to 209 mm Hg (P=0.001) and decreased end-diastolic wall stress from 48 to 34 mm Hg (P=0.005).