THE INFLUENCE OF AMBULATORY BLOOD PRESSURE ON THE ASSOCIATIONS OF SEX WITH CARDIOVASCULAR EVENTS AND MORTALITY IN PATIENTS UNDERGOING HEMODIALYSIS: A PROSPECTIVE COHORT STUDY

Abstract

Objective: Male patients with pre-dialysis CKD have worse ambulatory BP control than females and this is associated with higher mortality risk. Male hemodialysis patients have higher ambulatory BP levels compared to females. The aim of this study was to investigate the influence of ambulatory BP on the associations of sex with cardiovascular events and mortality in hemodialysis individuals. Design and method: 129 male and 91 female hemodialysis patients with valid 48-hour ABPM were followed prospectively for 53.4±31.1 months. The primary endpoint was cardiovascular mortality; the secondary endpoint was a composite of cardiovascular death, non-fatal myocardial infarction, non-fatal stroke, resuscitation after cardiac arrest, hospitalization for heart failure, coronary or peripheral revascularization procedure. Results: Cumulative-freedom from the primary endpoint was significantly lower for women (logrank-p = 0.032), while cumulative-freedom from the secondary endpoint did not differ significantly between the two groups (logrank-p = 0.644). The crude risk for cardiovascular mortality was significantly higher for women (HR = 1.613, 95% CI [1.037, 2.509]). The crude risk for the combined cardiovascular endpoint was not different between the two genders (HR = 0.918, 95% CI [0.638, 1.320]). After adjusting for other risk factors (age, diabetes, dialysis vintage, coronary disease) no significant differences in the risk for both the primary and the secondary endpoint were observed between women and men (primary: HR = 1.464 (95% CI [0.929, 2.307]), secondary: 0.866 (95% CI [0.596, 1.260])). After additional adjustment for 44-hour ambulatory BP the above relationships did not alter (primary: HR = 1.498, 95% CI [0.947, 2.368]), secondary: (HR = 0.911, 95%CI [0.625, 1.327])). Conclusions: In contrast to patients with pre-dialysis CKD, ambulatory BP does not appear to significantly influence the relationship between gender and adverse cardiovascular outcomes in hemodialysis patients.