The Acute Hemodynamic Effects of MitraClip Therapy

OBJECTIVES: The objective of this study was to evaluate the acute hemodynamic consequences of mitral valve (MV) repair with the MitraClip device (Abbott Vascular, Menlo Park, California). BACKGROUND: Whether surgical correction of mitral regurgitation (MR) results in a low cardiac output (CO) state because of an acute increase in afterload remains controversial. The acute hemodynamic consequences of MR reduction with the MitraClip device have not been studied. METHODS: We evaluated 107 patients with cardiac catheterization before and immediately following percutaneous MV repair with the MitraClip device. In addition, pre- and post-procedural hemodynamic parameters were studied by transthoracic echocardiography. RESULTS: MitraClip treatment was attempted in 107 patients, and in 96 (90%) patients, a MitraClip was deployed. Successful MitraClip treatment resulted in: 1) an increase in CO from 5.0 ± 2.0 l/min to 5.7 ± 1.9 l/min (p = 0.003); 2) an increase in forward stroke volume (FSV) from 57 ± 17 ml to 65 ± 18 ml (p < 0.001); and 3) a decrease in systemic vascular resistance from 1,226 ± 481 dyn·s/cm(5) to 1,004 ± 442 dyn·s/cm(5) (p < 0.001). In addition, there was left ventricular (LV) unloading manifested by a decrease in LV end-diastolic pressure from 11.4 ± 9.0 mm Hg to 8.8 ± 5.8 mm Hg (p = 0.016) and a decrease in LV end-diastolic volume from 172 ± 37 ml to 158 ± 38 ml (p < 0.001). None of the patients developed acute post-procedural low CO state. CONCLUSIONS: Successful MV repair with the MitraClip system results in an immediate and significant improvement in FSV, CO, and LV loading conditions. There was no evidence of a low CO state following MitraClip treatment for MR. These favorable hemodynamic effects with the MitraClip appear to reduce the risk of developing a low CO state, a complication occasionally observed after surgical MV repair for severe MR.