Cardiovascular risk stratification in hypertensive patients: Impact of echocardiography and carotid ultrasonography

BACKGROUND: Decision about the management of hypertensive patients should not be based on the level of blood pressure alone, but also on the presence of other risk factors, target organ damage (TOD) and cardiovascular and renal disease. OBJECTIVE: To evaluate the impact of echocardiography and carotid ultrasonography in a more precise stratification of absolute cardiovascular risk. METHODS: Never-treated essential hypertensives (n = 141; 73 men, 68 women, mean age 46 +/- 11 years) referred for the first time to our out-patient clinic were included in the study. They underwent the following procedures: (1) family and personal medical history, (2) clinical blood pressure (BP) measurement, (3) routine blood chemistry and urine analysis, (4) electrocardiogram, (5) echocardiogram, (6) carotid ultrasonogram. Risk was stratified according to the criteria suggested by the 1999 WHO/ISH guidelines. TOD was initially evaluated by routine procedures only, and subsequently reassessed by using data on cardiac and vascular structure obtained by ultrasound examinations (left ventricular hypertrophy (LVH) as left ventricular mass index (LVMI) > 134 g/m2 in men and > 110 g/m2 in women; carotid plaque as focal thickening > 1.3 mm). RESULTS: According to the first classification 20% were low-risk patients, 50% medium-risk, 22% high-risk and 8% very-high-risk patients. A marked change in risk stratification was obtained when TOD was assessed by adding ultrasound examinations: low-risk patients 18%, medium-risk 28%, high-risk 45%, very-high-risk patients 9%. CONCLUSIONS: The detection of TOD by ultrasound techniques allowed a much more accurate identification of high-risk patients, who represented a very large fraction (45%) of the patient population seen at our hypertension clinic. In particular, a large proportion of patients classified as at moderate risk by routine investigations were instead found to be at high risk when ultrasound examinations were added. The results of this study suggest that cardiovascular risk stratification only based on simple routine work-up can often underestimate overall risk, thus leading to a potentially inadequate therapeutic management especially of low-medium risk patients.