Combined effect of albuminuria and estimated glomerular filtration rate on cardiovascular events and all-cause mortality in uncomplicated hypertensive patients

Objectives: Decreased glomerular filtration rate (GFR) and microalbuminuria predict cardiovascular events and mortality in the general population and in high-risk patients. Their combined prognostic power in low-risk patients has never been reported. We assessed the prognostic role of GFR and albuminuria for cardiovascular disease and all-cause mortality in nondiabetic patients with primary hypertension. Methods: We conducted an 11.2-year follow-up of 837 uncomplicated hypertensive patients enrolled in the Microalbuminuria: A Genoa Investigation on Complications (MAGIC) cohort between 1993 and 1997. Urinary albumin to-creatinine ratio (ACR) and estimated GFR (eGFR) were assessed in untreated patients at baseline. Renal dysfunction was defined as the inclusion in the most unfavorable sex-specific decile of eGFR or of ACR. The primary endpoints were the occurrence of fatal and nonfatal cerebrovascular and cardiac events (CVEs), composite of nonfatal cerebrovascular and cardiac events (CVD) and all cause death (CEP), and composite of CVD and chronic renal insufficiency (CRE). Results: During 9374 person-years of follow-up, the incidence rate for CVE, CRE, and all-cause mortality was 6.3, 7.8, and 3.1 /1000 person-years, respectively. Renal dysfunction was associated with increased risk for CVE [relative risk (RR) 2.13, 95% confidence interval (CI) 1.15–3.93, PU0.011], CEP (RR 1.78, 95% CI 1.02–3.08, PU0.027), and CRE (RR 2.47, 95% CI 1.45–4.29, P<0.001), even after adjusting for several baseline covariates such as sex, duration and severity of blood pressure, and total cholesterol. Conclusion: Renal dysfunction is a risk factor for cardiorenal events and all-cause mortality, regardless of traditional confounders, in uncomplicated patients with primary hypertension.