Development of chronic kidney disease and cardiovascular prognosis in essential hypertensive patients

The existence of a significant percentage of treated hypertensive patients presenting a diminished renal function has been recently described. Mild renal function abnormalities are recognized as powerful predictors of cardiovascular morbidity and mortality. However, longitudinal data demonstrating this association are lacking. The objectives of this study have been analysis of the evolution of GFR, assessed as creatinine clearance (CrCl), during long-term follow-up of hypertensive patients and evaluation of the impact of the development of chronic kidney disease (CKD) on cardiovascular prognosis. A historical cohort of 281 patients attending our Hypertension Unit was selected according to the following criteria: essential hypertension, more than 5 yr of follow-up, and normal GFR at baseline (CrCl > 90 ml/min per 1.73 m(2)). Patients had an average follow-up of 13.2 +/- 4.8 yr. Forty-one patients (14.6%) developed CKD (CrCl < 60 ml/min per 1.73 m(2)) attributed to hypertensive nephrosclerosis. Initial serum creatinine, age, systolic BP at baseline, and average total cholesterol during follow-up were independent predictors of CKD development. Forty-nine (17.4%) of 281 patients presented a cardiovascular event during follow-up: 17 patients (40.6%) who developed CKD and 32 patients (13.3%) with preserved renal function (log rank test P < 0.001). After adjustment in a Cox multivariate analysis, age, development of CKD during follow-up, and male gender were independent predictors of the appearance of cardiovascular events. In essential hypertensive patients with normal renal function at baseline, the development of CKD during the follow-up is strongly and independently related with poor cardiovascular prognosis.