Long-term mortality and predictive score performance in Brazilian atherosclerotic renovascular disease patients

Abstract

INTRODUCTION: Atherosclerotic renovascular disease (ARVD) can cause renal artery stenosis, hypertension, and chronic kidney disease. As revascularization procedure for ARVD is controversial, a risk score was developed to predict mortality in affected patients, which requires validation in different populations. The original risk score did not include statin use; therefore, the aim of this study was to evaluate the accuracy of the risk score in ARVD patients according to statins intake. METHODS: Longitudinal retrospective study involving 136 patients with angiographic diagnosis of RAS > 60% from January 1996 to October 2008. Cox regression analysis was performed to assess all-cause mortality associations. To evaluate the discriminatory power of the risk score, ROC curves were constructed for mortality at 1, 5, and 10 years for those with and without statin use. RESULTS: 103 patients were included, 69 of whom were taking statins. After 1, 5, and 10 years, survival rates predicted by the risk score for patients using statins were, respectively, 0.87 (95% CI [0.76;0.97]), 0. 45 (95% CI [0.37;0.55]), and 0.15 (95% CI [0.09;0.22]). Actual survival rates were 0.95, 0.88, and 0.72. For the 34 patients who did not use statins, predicted survival rates were 0.84 (95% CI [0.71;0.97]), 0.43 (IC 95% [0.32;0.55]), and 0.14 (95% CI [0.05;0.22]); actual survival rates were 0.83, 0.36, and 0.29. CONCLUSION: Patients receiving statins had greater survival rate after 5 and 10 years when compared to calculations by the risk score. The 34 patients who did not use statins had survival rates close to the predicted survival. Therefore, the risk score should be modified to include use of statins.