Miho Fukui MD,PhD; Hiroki Niikura MD; Paul Sorajja MD; Go Hashimoto MD; Richard Bae MD; Santiago Garcia MD; Mario Gössl MD, PhD; João L. Cavalcante MD
Valve Science Center, Minneapolis Heart Institute Foundation, Abbott Northwestern Hospital, Minneapolis, Minnesota
Journal of the American Society of the Echocardiography, available online 9 September 2020 https://doi.org/10.1016/j.echo.2020.07.003
Highlights
Mortality in high-risk severe MR patients treated with MitraClip was associated with baseline GLS values.
Reduced GLS at baseline was associated with 1-year all-cause mortality.
Results may improve current risk stratification in patients considered for MitraClip therapy.
Background
Transcatheter mitral valve repair (TMVr) using edge-to-edge mitral valve clip is effective for patients with mitral regurgitation (MR) and high or prohibitive surgical risk. Global longitudinal strain (GLS) allows evaluation of subclinical myocardial dysfunction, but its incremental clinical utility into risk stratification, beyond traditional clinical parameters, is unknown in patients treated with TMVr. We sought to evaluate the association of baseline GLS with 1-year all-cause mortality in patients treated with TMVr using edge-to-edge mitral valve clip.
Methods
We analyzed 155 patients who underwent transcatheter edge-to-edge mitral valve clip implantation (mean age, 83 ± 7 years; 48% were women; mean left ventricular ejection fraction, 56% ± 10%, Society of Thoracic Surgeons Predicted Risk of Mortality score for repair, 6.62% ± 5.22%). Baseline left ventricular GLS was obtained by two-dimensional speckle-tracking echocardiography, averaging 18 segments from three apical views. Receiver operating characteristic analyses were used to assess the GLS cut point associated with all-cause mortality. Multivariable models with Cox regression tested its relationship after adjustment for baseline comorbidities.
Results
During a median follow-up of 316 days, all-cause deaths occurred in 30 patients at a median of 156 days after TMVr. The area under the curve of preoperative GLS associated with the outcome was 0.60, with a cutoff point of −14.5%. Baseline GLS > −14.5% was associated with 1-year mortality (hazard ratio = 2.50; 95% CI, 1.20-5.21; P = .02) before and after adjustment for baseline characteristics. After accounting for baseline characteristics, patients with GLS > −14.5% had worse 1-year mortality than those with GLS ≤ −14.5% (χ2 P < .001). In nested Cox proportional hazards models, the addition of baseline GLS to Society of Thoracic Surgeons Predicted Risk of Mortality score, left ventricular ejection fraction, and the etiology of MR significantly increased the model χ2 value (χ2 = 12.32).
Conclusions
Baseline GLS is independently associated with 1-year all-cause mortality in patients who undergo TMVr, and its assessment improves risk stratification in these patients.
Keywords
All-cause mortalityGlobal longitudinal strainMitral regurgitationTranscatheter edge-to-edge mitral valve clipTranscatheter mitral valve repair
Abbreviations
DMR Degenerative mitral regurgitation; FMR Functional mitral regurgitation; GLS Global longitudinal strain; LV Left ventricular; LVEF Left ventricular ejection fraction; LVESD Left ventricular end-systolic diameter; MR Mitral regurgitation; MV Mitral valve; STS-PROM Society of Thoracic Surgeons Predicted Risk of Mortality; TMVr Transcatheter mitral valve repair; TTE Transthoracic echocardiography