Renal and cardiac abnormalities in primary hypertension

OBJECTIVE: The relationship between mild reduction in renal function and cardiac structure and function have not yet been fully elucidated. We investigated cardiac and renal abnormalities in 400 untreated, nondiabetic patients (65% men, mean age 47 years) with primary hypertension and normal serum creatinine. METHODS: Renal abnormalities were defined as creatinine clearance less than 75 ml/min per 1.73 m2 (Cockcroft-Gault formula) and/or the presence of microalbuminuria (albumin-to-creatinine ratio). Left ventricular structure and function were assessed by echocardiography. RESULTS: The prevalence of microalbuminuria and reduced creatinine clearance was 13 and 31%, respectively. Patients with renal abnormalities shared greater left ventricular mass index, higher prevalence of left ventricular hypertrophy, and unfavorable geometric patterns. Microalbuminuria was also associated with inappropriate left ventricular mass and depressed midwall fractional shortening, whereas reduced creatinine clearance was associated with lower stroke volume and higher central pulse pressure/stroke volume ratio and total peripheral resistance. Stepwise regression analysis showed that both albuminuria and creatinine clearance were independently related to left ventricular mass. Logistic regression analysis of the reciprocal interaction of microalbuminuria and reduced creatinine clearance on the occurrence of subclinical cardiac damage showed that reduced creatinine clearance entailed a greater risk of left ventricular hypertrophy in patients with normal albuminuria alone, whereas the presence of microalbuminuria was associated with a greater risk of left ventricular hypertrophy independently of creatinine clearance. CONCLUSIONS: These findings provide further proof of the role of cardiorenal interaction in the development of hypertension-related cardiovascular disease, and may have clinical implications.