Identification of Subclinical Myocardial Dysfunction and Association with Survival after Transcatheter Mitral Valve Repair.

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% (χ2P < .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.