Prognostic value of microalbuminuria during antihypertensive treatment in essential hypertension

Abstract

Whether changes over time of urinary albumin excretion have prognostic value is a matter of discussion. The objective was to assess the prognostic value of changes in urinary albumin excretion over time in cardiovascular risk during antihypertensive treatment. Follow-up study of 2835 hypertensives in the absence of previous cardiovascular disease (mean age 55 years, 47% men, BP 138/80 mm Hg, 19.1% diabetics, and calibrated systemic coronary risk estimation 5 or >10.6%). Usual-care of antihypertensive treatment was implemented to maintain blood pressure <140/90 mm Hg. Urinary albumin excretion was assessed yearly, and the values were expressed as the creatinine ratio. Incidence of cardiovascular events, fatal and nonfatal, was recorded during the follow-up. During a median follow-up of 4.7 years (17 028 patients-year), 294 fatal and first nonfatal cardiovascular events were recorded (1.73 CVD per 100 patients/year). Independently of blood pressure, estimated glomerular fltration rate, level of cardiovascular risk, and antihypertensive treatment, microalbuminuria at baseline and at any time during the follow-up resulted in higher risk for events, hazard ratio (HR) 1.35 (95% confidence interval [CI], 1.08-1.79) and HR 1.49 (95% CI, 1.14-1.94), respectively. Likewise, development of microalbuminuria (HR 1.60; 95% CI, 1.04-2.46) or persistence from the beginning (1.53; 95% CI, 1.13-2.06) had a significantly higher rate of events than if remained normoalbuminuric (HR 1) or regress to normoalbuminuria (HR 1.37; 95% CI, 0.92-2.06) with an 18%, 18%, 8%, and 11% events, respectively, P<0.001. The study supports the value of urinary albumin excretion assessment as a prognostic factor for cardiovascular risk, but also opens the way to consider it as an intermediate objective in hypertension.