Abstract 15528: Percutaneous Mitral Valve Intervention with Mitraclip Reduces Backward Failure Quantified as the Pulmonary Blood Volume Measured by Cardiovascular Magnetic Resonance Imaging
INTRODUCTION: Mitral regurgitation is associated with backward failure and pulmonary congestion, and can be challenging to assess quantitatively by echocardiography. The pulmonary blood volume (PBV) measured by cardiovascular magnetic resonance (CMR) may provide a quantitative measure of backward failure in mitral regurgitation.
AIMS: To quantify the PBV before and after percutaneous mitral valve intervention (MitraClip). We hypothesized that patients would have an increased PBV compared to controls, and that PBV would decrease after MitraClip.
MATERIALS AND METHODS: Patients underwent CMR before (n=9, 58-89 years) and 1-3 months after (n=7) MitraClip. Ten healthy controls were included (25-71 years). PBV was quantified by CMR as cardiac output, from aortic flow multiplied by the pulmonary transit time for an intravenous contrast bolus. Mitral regurgitation was measured as left ventricular stroke volume (cine) minus stroke volume (aortic flow).
RESULTS: Patients had a higher PBV compared to controls (553ml (range 258-748ml) vs 430ml (342-537ml), p=0.04). After MitraClip, there was a decrease in PBV (421ml (217-598ml), p=0.03, p=0.85 vs controls). The volume of mitral regurgitation in patients was higher compared to controls (47ml (9-84ml) vs 15ml (5-29ml), p=0.002), and decreased to 22ml (0-70ml) after MitraClip (p=0.03, p=0.38 vs controls).
CONCLUSIONS: Patients had a higher PBV compared to controls, consistent with backward failure in severe mitral regurgitation. Mitral regurgitation and the PBV both decreased after MitraClip, suggesting that the procedure alleviates backward failure, and that this can be monitored using PBV measurements by CMR.
- © 2012 by American Heart Association, Inc.