Comparison of classification of the severity of hypertension by blood pressure level and by World Health Organization criteria in the prediction of concurrent cardiac abnormalities and subsequent complications in essential hypertension

Abstract

To determine whether classification of the severity of hypertension according to the World Health Organization (WHO) system, which utilizes additional clinical and laboratory findings, is superior to classification by blood pressure level alone in predicting prognostically important cardiac structural abnormalities and the risk of subsequent complications in asymptomatic subjects. Two-hundred and twenty adults with uncomplicated essential hypertension underwent baseline clinical evaluation and echocardiography; 88% were subsequently followed for a mean of 11.6 years. University hospital. Left ventricular mass index and relative wall thickness were slightly greater in patients in the highest diastolic or systolic blood pressure stratum than in WHO stage II hypertensives, but these results were statistically non-significant. High peripheral resistance index was best identified by diastolic blood pressure level. Receiver operating characteristic curve analysis showed that all three methods had similar test performance in predicting abnormal left ventricular mass index, left ventricular geometry, relative wall thickness and peripheral resistance. During follow-up the proportion of patients who had a clinical event or died increased with increasing severity stratum in all three clinical classification systems, but the trends were statistically non-significant. Risk stratification by echocardiographic left ventricular mass index was most successful in identifying patients at very high and very low risk of subsequent morbid events and all-cause mortality. Classification of hypertension severity by blood pressure level has similar, although limited, effectiveness at a lower cost than the WHO criteria in identifying patients with adverse cardiac changes and an impaired long-term prognosis. Echocardiographic measurement of left ventricular mass index was more successful than other classifications in predicting subsequent morbid events.