The MitraClip and survival in patients with mitral regurgitation at high risk for surgery: A propensity-matched comparison
Eric J. Velazqueza b✉, Zainab Z. Samadc, Hussein R. Al‐Khalidia, Chithra Sanglid, Paul Arthur Grayburne, Joseph M. Massarof, Susanna R. Stevensa, Ted E Feldmang, Mitchell W. Krucoffa c
- aDuke Clinical Research Institute, Duke University Medical Center, Durham, NC
- bDivision of Cardiology, Duke University Medical Center, Durham, NC. Electronic address: eric.velazquez@duke.edu
- cDivision of Cardiology, Duke University Medical Center, Durham, NC
- dAbbott Vascular, Abbott Park, IL
- eBaylor Heart and Vascular Institute, Dallas, TX
- fHarvard Clinical Research Institute, Boston, MA
- gNorthShore University HealthSystem Evanston Hospital, Evanston, IL
- ✉Corresponding author
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Abstract
Background: We compared 30-day and 1-year survival among high-risk mitral regurgitation (MR) patients treated with the MitraClip (Abbott Vascular, Abbott Park, IL) with matched non-surgically treated patients from the Duke Echocardiography Laboratory Database (DELD). Methods and results: High-risk patients with 3+/4+ MR managed non-surgically between years 2000 and 2010 in the longitudinal DELD were matched to high-risk MitraClip patients. Patient matching was performed using the method of nearest available Mahalanobis distance metric within calipers defined by the propensity score. Kaplan-Meier estimates and stratified Cox proportional hazards models were used to compare survival at 30 days and 1 year. Among 953 high-risk DELD patients available for matching, 30-day and 1-year mortality were 6.5% and 26.2%. Close matches were obtained for 239 of the 351 MitraClip patients. The 30-day mortality in MitraClip patients was lower (4.2%) when compared with matched DELD patients (7.2%). The 1-year relative risk of mortality of the MitraClip compared with non-surgical treatment was 0.64 (95% CI 0.45-0.91; log-rank P = .013). These results in favor of the MitraClip remained significant upon further adjustment for baseline differences between groups (P = .043). Conclusions: This matched comparison of severe MR patients at high surgical risk supports the safety of the MitraClip relative to medical therapy at 30 days and a survival benefit at 1 year.