Prognostic Value of Coronary Flow Reserve on Long-Term Cardiovascular Outcomes in Patients With Chronic Kidney Disease

Cardiovascular (CV) diseases and chronic kidney disease (CKD) have common predisposing factors that subsequently cause microvascular dysfunction. In the absence of obstructive coronary artery disease, coronary flow reserve (CFR) represents the status of coronary microcirculation. This study aimed to investigate the prognostic importance of impaired CFR, as a marker of microvascular dysfunction, on long-term CV outcomes in patients with CKD. This study consisted of 139 patients with an estimated glomerular filtration rate of <60 ml/min/1.73 m2 who had no obstructive narrowing of the left anterior descending artery. Transthoracic Doppler echocardiography was used to measure CFR in the left anterior descending artery. During the follow-up period (3.3 ± 1.6 years), CV events occurred in 26 patients (18.7%). Multivariate analysis that included CFR as a continuous value identified a serum level of C-reactive protein (hazard ratio 1.41, p = 0.03) and a value of CFR (hazard ratio 0.21, p = 0.009) as determinants for CV events, independent of traditional CV risk factors. Patients with a CFR of <2.0 had worse CV outcomes compared with those with a CFR of ≥2.0 (p <0.001). In conclusion, transthoracic Doppler echocardiographically derived CFR was useful for the risk stratification of CV outcomes in patients with CKD. The presence of microvascular dysfunction may play an important role in the association between CKD and future CV events.