The impact of left ventricular hypertrophy on early and long-term survival after coronary artery bypass grafting

Left Ventricular Structure is Associated with Postoperative Death After Coronary Artery Bypass Grafting in Patients with Heart Failure with Reduced Ejection Fraction

Background

The relationship between abnormal left ventricular (LV) structure and adverse outcomes has been confirmed in diverse patient groups in previous studies. However, it remains uncertain whether LV structure has predictive implications in heart failure with reduced ejection fraction (HFrEF) patients with coronary artery bypass grafting (CABG).

Methods

This study retrospectively enrolled patients who had HFrEF and underwent CABG between January 2013 and July 2019. According to LV hypertrophy (LVH) and LV enlargement (LVE) assessed by echocardiography, patients were classified into four LV structure types: (-)LVH/(-)LVE, (+)LVH/(-)LVE, (-)LVH/(+)LVE, and (+)LVH/(+)LVE.

Results

A total of 435 consecutive patients (mean age: 59.4 ± 9.6 years; 14.9% female) were enrolled in the present study. Examined independently, either LVH (p < 0.001) or LVE (p < 0.001) was independently associated with postoperative mortality in multivariate analysis. When LVH and LVE were analyzed in combination, the risk of mortality after CABG was lowest in (-)LVH/(-)LVE and increased with (+)LVH/(-)LVE (odds ratio [OR]: 7.525; 95% confidence interval [CI]: 1.827–30.679, p = 0.004), (-)LVH/(+)LVE (OR: 7.253; 95% CI: 1.950–27.185, p = 0.003), and (+)LVH/(+)LVE (OR: 9.547; 95% CI: 2.726–34.805, p < 0.001), independent of other risk factors. Adding LV structural types to the baseline model gained an incremental effect on the predictive value for postoperative mortality (AUC: baseline model, 0.838 vs baseline model + LV structural types, 0.901, p for comparison = 0.010; category‐free net reclassification improvement (NRI): 0.764, p < 0.001; integrated discrimination improvement (IDI): 0.061, p = 0.007).

Conclusion

LVH and LVE were associated with an increased risk of postoperative mortality after CABG in patients with HFrEF. Categorizing LV structural patterns with LVH and LVE contributes to risk stratification and provides incremental predictive ability. Routine echocardiographic assessment of LVH and LVE is needed in clinical practice.

Coronary artery bypass surgery in patients with low EuroSCORE preoperative risk

Patients with EuroSCORE <2 are usually considered to have a low surgical risk and the lowest mortality. In our study preoperative factors in a group of 250 consecutive low-risk patients (EuroSCORE<2), who underwent first isolated coronary artery by-pass surgery during 1999 and 2000., were analyzed. Cumulative follow-up period was 1178.48 patient-years and the primary clinical outcome was all-cause mortality. Patients’ average age was 59.2±7.5 yr. The following preoperative risk factors of increased 5-year mortality were identified: older age (P<0.001), smoking, prior non-recent myocardial infarction and reinfarction, anteroseptal localization of myocardial infarction (P<0.001), poor ejection fraction<=35% (P<0.001), dilatative cardiomyopathy (P<0.001), wall motion systolic index 〉2 (P<0.001), left atrial dilatation (P<0.001), mitral regurgitation more than 2+ (P<0.001), presence of left main disease, triple vessel coronary artery disease (P<0.001), absence of collaterals (P<0.001) and presence of more than 3 distal anastomoses. Through the present study it has been shown that it is possible to identify a subgroup of patients with low operative mortality and excellent 5-year survival after surgical treatment for coronary artery bypass surgery using preoperative clinical, echocardiographic, coronarographic and intraoperative data, even in difficult conditions of the civil war in the region.