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 ')-which are 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 <= 19 m/s and E/e ' <= 15 (reference), baPWV > 19 m/s and E/e ' <= 15 (high-PWV-only), baPWV <= 19 m/s and E/e ' > 15 (high-E/e '-only), and baPWV > 19 m/s and E/e ' > 15 (high-PWV-and-E/e '). After inverse probability treatment weighting adjustment, 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 69 years and 57.2 months, respectively. Both postoperative acute kidney injury (POAKI) and atrial fibrillation (POAF) were higher in the high-PWV-and-E/e ' group (adjusted odds ratio (OR) = 89.5; 95% confidence interval (CI), 8.5-942.3; p < 0.001 and OR = 12.5; CI, 2.5-63.8; p = 0.002, respectively). Compared to the reference group, only the high-PWV-and-E/e ' group showed significantly lower survival rate (91.0%; CI, 82.8-100% vs. 44.8%; CI, 21.2-94.6%) and a higher hazard for all-cause mortality after adjustment for covariates (hazard ratio = 6.1; p = 0.002). Conclusion Concurrent elevation in PWV and E/e ' may independently affect not only the rates of POAKI and POAF but also long-term survival after OPCAB.