Left ventricular regional dyssynchrony predicts improvements in moderate ischaemic mitral regurgitation after off-pump coronary artery bypass

Nomogram Predicts Improvement of Ischemic Mitral Regurgitation after Coronary Artery Bypass Grafting

BACKGROUND

Developing a nomogram to predict improvement in moderate ischemic mitral regurgitation (IMR) after coronary artery bypass grafting (CABG) is in need.

METHODS

Between 2010 and 2018, data were retrospectively collected from 112 patients with prior myocardial infarction and moderate IMR undergoing CABG. Patients were divided into two groups based on IMR degree 1 year after CABG as follows: Improved Group with no or mild IMR (n=54) and Failure Group with moderate or severe IMR (n=58). To determine the predictors of postoperative IMR improvement, preoperative clinical and echocardiographic data were compared, and a nomogram was formulated based on all independent predictors. Discriminative ability, calibration, and clinical usefulness of the prediction model were assessed.

RESULTS

Independent predictors of IMR improvement after CABG constructing the nomogram included duration between infarction and operation, poster-inferior to left ventricular volume ratio, maximum difference of the time to reach minimum systolic volume of 16 segments, P3 leaflet tethering angle, and annular Non-planar angle. The nomogram exhibited well-fitted calibration curves and excellent discriminative ability. The area under receiver operating characteristic curve was 0.974. Patients with a score > 236 demonstrated a high probability of IMR improvement (sensitivity, 90.7%; specificity, 93.1%). Patients in the Improved Group demonstrated greater actuarial survival rates than those in the Failure Group.

CONCLUSIONS

The nomogram combining 5 preoperative clinical and echocardiographic predictors provides an accurate preoperative estimation of moderate IMR improvement after surgery, with excellent discriminative ability. Based on this nomogram, patients with a higher score predict higher probabilities of IMR improvement.

Predictive impact of previous coronary artery bypass grafting on mortality after MitraClip implantation for ischemic functional mitral regurgitation

BACKGROUND

Many candidates with ischaemic functional mitral regurgitation (FMR) have previously undergone coronary artery bypass grafting (CABG), in which transcatheter mitral valve repair can be reasonable for ameliorating the deteriorated hemodynamic and heart failure symptoms. We sought to elucidate the outcomes of MitraClip (MC) implantation in patients with symptomatic ischaemic FMR after CABG.

METHODS

We investigated clinical characteristics, outcomes and predictive impact of previous CABG on mortality in ischaemic FMR patients who underwent MC implantation from two high-volume centres in Germany.

RESULTS

We enrolled 159 patients who previously underwent CABG. Compared with a reference group that did not previously undergo CABG (n = 182), the cohort consisted of more elderly patients (75.0, standard deviation [SD] 7.7 versus 72.9, SD 9.6 years, p = 0.028), more men (84% vs. 69%, p < 0.001), and reduced tricuspid annular plane systolic excursion (14.0, SD 4.0, vs. 16.6, SD 4.6 mm, p < 0.0001). The CABG group showed similar outcomes regarding procedural success (91% vs. 94%, p = 0.24) and 30-day mortality (5.0% vs. 6.0%, p = 0.68), but worse survival after MC implantation (log-rank p = 0.019, hazard ratio 1.56 [95% confidence interval (CI) 1.08-2.26]). After propensity score matching (n = 224), the hazard ratio was 1.18 [95%CI 0.76-1.84] without statistical significance (p = 0.46).

CONCLUSIONS

Transcatheter mitral valve repair using the MC is a viable treatment option for patients with symptomatic ischaemic FMR after CABG. Although the baseline characteristics seemed to point to sick patients, CABG itself had only a modest impact on survival.