Role of echocardiography and carotid ultrasonography in stratifying risk in patients with essential hypertension: the Assessment of Prognostic Risk Observational Survey

Abstract

BACKGROUND: Echocardiography and carotid ultrasonography, by providing a more accurate assessment of cardiac and vascular damage related to hypertension, may lead to a more precise stratification of the global cardiovascular risk. However, current guidelines do not recommend systematic use of ultrasound examination of heart and large arteries in evaluating the cardiovascular risk in patients with hypertension. OBJECTIVE: To assess the impact of echocardiography and carotid ultrasonography on global risk stratification in hypertensive patients classified as being at low or medium risk according to routine clinical work-up as suggested by current hypertension guidelines. METHODS: Among 8502 consecutive patients screened at 44 outpatient hypertension hospital clinics in different parts of Italy, 1074 untreated individuals with low-to-medium risk essential hypertension were identified on the basis of the diagnostic routine procedures suggested by 1999 World Health Organization/International Society of Hypertension guidelines: medical history, physical examination and clinic blood pressure measurement; routine blood chemistry and urine analysis; electrocardiogram. The extent of risk for the 1074 individuals was reassessed by adding the results of ultrasound examinations of heart and carotid arteries: left ventricular hypertrophy (defined as left ventricular mass index > 120 g/m(2) in men and > 100 g/m(2) in women), carotid intima-media thickening (defined as diffuse thickening if >or= 0.8 mm), and presence of plaque (defined as focal thickening > 1.3 mm). RESULTS: According to routine classification, 18.7% (n = 201) of the 1074 patients were considered at low risk and 81.3% (n = 873) at medium risk. A marked change in risk stratification was obtained when ultrasound markers of target-organ damage were taken into consideration: the proportion of low-risk patients decreased to 11.1%, and that of medium risk patients to 35.7%, whereas more than 50% of the patients previously classified at low-medium risk were found to be at high absolute risk. According to a multivariate analysis, age, grade of hypertension, male sex, and serum cholesterol concentration were the variables with the greatest impact on risk class change. CONCLUSIONS: Ultrasound assessment of the heart and carotid wall helps to obtain a more valid assessment of global cardiovascular risk in hypertensive patients without evidence of target-organ damage after routine examination.