Combined impact of elevated arterial stiffness and left ventricular filling pressure on outcomes after off-pump coronary artery bypass grafting

Abstract

Background: Brachial-ankle pulse wave velocity (baPWV) and early diastolic transmitral flow velocity to mitral annular tissue velocity (E/e’), markers of arterial stiffness and left ventricular (LV) filling pressure, respectively, have been associated with morbidity and mortality. We investigated their combined impact on postoperative complications and long-term survival of patients undergoing off-pump coronary artery bypass grafting (OPCAB). Methods: A cohort of 164 patients were divided into four groups: baPWV≤19m/s and E/e’≤15 (reference), baPWV>19m/s and E/e’≤15 (high-PWV-only), baPWV≤19m/s and E/e’>15 (high-E/e’-only), and baPWV>19 m/s and E/e’>15 (high-PWV-and-E/e’). Each group was compared with the reference group to analyze the odds ratios of postoperative complications and the Kaplan-Meier survival curves, and to identify the group representing an independent prognostic predictor. Results: The median age and follow-up duration were 66.2 years and 57.2 months, respectively. Postoperative acute kidney injury (POAKI) was higher in the high-PWV-only group and substantially higher in high-PWV-and-E/e’ group (adjusted odds ratio (OR)=4.8; 95% confidence interval (CI), 1.3-17.1; p=0.016 vs. OR=22.6; CI, 5.9–86.1; p<0.001). ORs of postoperative atrial fibrillation (POAF) and postoperative stroke/delirium (POSD) were significantly higher only in the high-PWV-and-E/e’ group. The 7-year survival rates differed across the groups (p<0.001). The high-E/e’-only and high-PWV-and-E/e’ groups showed significantly lower survival rates than the reference group (75.6% and 53.5% vs. 93.9%). After adjustment for covariates, however, only the high-PWV-and-E/e’ group turned out to be an independent predictor group for all-cause mortality. Conclusion: Concurrent elevation in PWV and E/e’ may independently affect not only the rates of POAKI, POAF, and POSD but also long-term survival after OPCAB.