Right ventricular strain predicts adverse outcomes in patients undergoing coronary artery bypass grafting

Patients undergoing coronary artery bypass grafting (CABG) face an elevated risk of heart failure (HF) and cardiovascular (CV) death. Detailed myocardial tissue analyses of the right ventricle are now possible and may hold prognostic value in these patients. Accordingly, we aimed to evaluate the usefulness of right ventricular (RV) layer-specific RV free wall strain (RVFWS) for predicting HF and/or CV death. Patients undergoing CABG at Gentofte Hospital from 2006 to 2011 with a preoperative echocardiogram underwent RVWFS analysis. RVFWS was obtained by speckle tracking. The outcome was defined as a composite of HF and/or CV death. Cox proportional hazards regression, Harrell's C-statistics, and competing risk regression were used to assess the prognostic value of RVFWS. Of 317 patients, 30 (9.5%) reached the endpoint at a median follow-up of 3.5 years. The mean age was 67 years, 83% were men, and the mean LVEF was 50%. In univariable analyses, endo-RVFWS (HR 1.08, P < 0.001), mid-RVFWS (HR 1.07, P = 0.002), and epi-RVFWS (HR 1.07, P = 0.004, per 1% absolute decrease) were associated with a higher risk of HF or/and CV death. Furthermore, all three layers remained independently associated with the outcome after multivariable adjustment for baseline clinical and echocardiographic measurements. Low endo-RVFWS was associated with a more than threefold increased risk of the outcome (HR = 3.04 (1.45-6.38) P = 0.003). The same was observed for mid-RVFWS (HR = 3.16 (1.45-6.91) P = 0.004), and epi-RVFWS (HR = 3.00 (1.46-6.17) P = 0.003). In patients undergoing CABG, RVFWS assessed by speckle-tracking is a predictor of adverse outcomes.