Derived Subendocardial Viability Ratio and Cardiovascular Events in Patients with Chronic Kidney Disease

BACKGROUND: Chronic kidney disease (CKD) is a well-known mortality risk factor. The subendocardial viability ratio (SEVR) is one of the pulse wave analysis parameters that constitutes a non-invasive measure of coronary perfusion. We aimed to assess the prognostic value of the SEVR for cardiovascular outcome in non-dialysis CKD patients. METHODS: A total of 98 CKD patients (mean age 60 years) were prospectively followed up from the date of the SEVR measurement until their death or the start of dialysis/transplantation, maximally up to 7.1 years (mean 5 years). According to the manufacturer's instructions regarding normal SEVR values, the patients were divided into a low SEVR group (SEVR ≤130%, n = 26) and a normal SEVR group (SEVR > 130%, n = 72). RESULTS: During the follow-up period, 13 patients (13.3%) suffered fatal and 23 patients (23.5%) suffered combined (non-fatal and fatal) cardiovascular events. In the patients who died of cardiovascular causes, the SEVR values were statistically significantly lower (130 vs. 154%; p = 0.017) than in those who survived. A Kaplan-Meier survival analysis showed that the cardiovascular survival rate in the low SEVR group of patients was statistically significantly lower (log-rank test: p < 0.001). Using an unadjusted Cox regression analysis, the patients in the low SEVR group had a 5.6-fold higher risk (95% CI: 1.8-17.3; p = 0.002) of fatal cardiovascular events and a 2.7-fold higher risk (95% CI: 1.1-6.3; p = 0.024) of combined fatal and non-fatal cardiovascular events. In the adjusted Cox regression model, the patients in the low SEVR group had a 16-fold higher risk (95% CI: 1.2-9.7; p = 0.004) of fatal cardiovascular events and a 7-fold higher risk (95% CI: 1-9.7; p = 0.009) of combined fatal and non-fatal cardiovascular events. CONCLUSIONS: An SEVR < 130% predicts fatal and non-fatal cardiovascular events in non-dialysis CKD patients.