Usefulness of microalbuminuria in cardiovascular risk stratification of essential hypertensive patients

Background/Aims: To evaluate the influence of microalbuminuria (albumin excretion rate – AER) determination and echocardiography (ECHO) on cardiovascular risk stratification, initially performed according the 1999 WHO/ISH guidelines by using only routine diagnostic procedures with or without fundal examination. Methods: 312 essential hypertensives attending our institution were studied retrospectively. Cardiovascular risk was assessed in a semiquantitative way using four categories of absolute cardiovascular disease risk (low, medium, high and very high risk), as proposed by the 1999 WHO/ISH guidelines, on the basis of data on the average 10-year risk of cardiovascular events among participants in the Framingham Study. Results: Without the retinal data, estimating the level of global cardiovascular risk on the basis of routine work-up alone, 14% were classified as low-risk patients, 48% were as medium-risk, 20% as high-risk and 18% at very-high-risk patients. The combined use of AER and ECHO, in line with the newer ESHESC guidelines, determined a statistically significant reclassification of the hypertensive patients. Only 10% remained in the low-risk category, 28% were classified in the medium-, 42% in the high- and 20% in the very-highrisk classes. The overall percentage of patients that changed risk stratum (mostly shifting from the mediumto the high-risk class) was significantly different from the proportion of subjects reclassified after the addition of either microalbuminuria or echocardiography alone. No change in the distribution of risk categories was observed when AER assay and ECHO were added to routine procedures including funduscopic examination. Conclusions: Considering the questionable prognostic value of qualitative retinal examination, our results suggest that cardiovascular risk evaluation based only on simple routine work-up, ignoring the information provided by AER determination and ECHO, may underestimate the level of absolute risk.