Prognostic implications of left ventricular geometry in coronary artery bypass grafting patients.

Background: The prognostic implications of left ventricular (LV) mass and geometry have been confirmed in populations with different cardiac diseases. However, the prognostic value of LV geometry in coronary artery bypass grafting (CABG) patients is unclear.

Methods: A total of 2,517 patients undergoing CABG between January 2012 and September 2016 in our cardiac surgery unit were included. Patients were divided into the following 4 groups according to left ventricular mass index (LVMi) and relative wall thickness (RWT): normal geometry, concentric remodeling, eccentric hypertrophy, and concentric hypertrophy.

Results: The median follow-up period was 47.0 months (interquartile range was 32.5-61.3 months). Compared to the normal geometry group, the concentric remodeling group [hazard ratio (HR): 3.023; 95% confidence interval (CI): 1.134-8.060], the eccentric hypertrophy group (HR: 3.422; 95% CI: 1.395-8.398), and the concentric hypertrophy group (HR: 5.399; 95% CI: 2.289-12.735) have higher main adverse cardiovascular and cerebrovascular event (MACCE) risk. Moreover, increased MACCE risk was associated with higher LVMi (HR: 1.015 per 1 g/m increase in LVMi; 95% CI: 1.005-1.026) and RWT (HR: 1.991 per 0.1-U increase in RWT; 95% CI: 1.343-2.952). We observed similar results concerning mortality. Adding LV geometry to the European System for Cardiac Operative Risk Evaluation (EuroSCORE) II significantly improved the area under the curve (AUC) for MACCE (from 0.621 to 0.703; P=0.042). The addition of LV geometry showed significant integrated discrimination improvement (IDI) and net reclassification improvement (NRI) for MACCE (IDI: 0.043, P<0.001; NRI: 0.200, P<0.001) and death (IDI: 0.018, P=0.020; NRI: 0.308, P=0.002), as was the addition of LVMi and RWT.

Conclusions: LV geometry is an independent and incremental prognostic factor for MACCE and death in CABG patients.