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.