THE IMPACT OF SEX ON THE RISK OF MAJOR ADVERSE CARDIOVASCULAR EVENTS IN OLDER ADULTS WITH ADVANCED CHRONIC KIDNEY DISEASE: RESULTS FROM THE EQUAL STUDY

Abstract BACKGROUND AND AIMS In the general population, men have a higher risk of major adverse cardiovascular events (MACE) compared with women, with this risk difference between men and women decreasing with increasing age. Patients with chronic kidney disease (CKD) are at a higher risk of MACE compared with the general population, but sex differences in this group, especially older adults, are not fully known. We aim to identify differences in the risk of (recurrent) MACE by sex in CKD patients over 65 years old from Europe and explore factors that may explain these differences. METHOD The European Quality study (EQUAL study) is a prospective study on stage 4–5 CKD patients not on dialysis from Germany, Italy, Poland, Sweden, the UK and the Netherlands who were ≥ 65 years old. Cox regression and cumulative incidence competing risk curves were used to calculate MACE risks. Mediation analysis was used to identify variables that may explain risk differences between men and women. RESULTS In 1136 men and 607 women, over a follow-up period of 5 years, 417 (37%) men and 185 (31%) women experienced at least one MACE, and there was a total of 1247 MACE. Men and women had 123 (14% of total MACE in men) and 54 (14% of total MACE in women) fatal MACE, respectively. The most common type of first MACE was peripheral vascular disease for men and congestive heart failure for women (Fig. 1). Accounting for the competing risk of non-MACE death, the probability of having a first MACE was 43% (95% CI: 40–47%) for men and 39% (95% CI: 34–44%) for women (Fig. 2), corresponding with a 18% lower relative risk of first MACE in women (HR: 0.82; 95% CI: 0.69–0.97; P = 0.02 ). There was no significant difference in the risk of recurrent MACE (HR: 0.91; 95% CI: 0.80–1.03; P = 0.14 ) or fatal MACE (HR: 0.84; 95% CI: 0.61–1.16; P = 0.30) between men and women. Adjusting for pre-existing comorbidities attenuated the MACE risk difference between men and women. MACE risk differences between men and women changed according to age group but not according to diabetes status. In those ≤ 75 years, women had a 25% lower risk of first MACE (HR: 0.75; 95% CI: 0.57–0.99; P = 0.04), which was 15% in those > 75 years old (HR: 0.85; 95% CI: 0.68–1.06; P = 0.14 ). The risk difference of fatal MACE between men and women differed greatly between those ≤ 75 years old (HR: 1.38; 95% CI: 0.82–2.33; P = 0.22 ) and those > 75 years (HR: 0.61; 95% CI: 0.41–0.93; P = 0.02). CONCLUSION Men had a higher probability of having a MACE over a 5-year period. Overall, women had lower risks of MACE compared with men, but risk differences between men and women changed with increasing age. Pre-existing comorbidities explained part of this risk difference.