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 COMPLICATIONSIN ESSENTIAL-HYPERTENSION

Objective: To determine whether classification of the severity of hype rtension according to the World Health Organization (WHO) system, whic h utilizes additional clinical and laboratory findings, is superior to classification by blood pressure level alone in predicting prognostic ally important cardiac structural abnormalities and the risk of subseq uent complications in asymptomatic subjects. Design: Two-hundred and t wenty adults with uncomplicated essential hypertension underwent basel ine clinical evaluation and echocardiography; 88% were subsequently fo llowed for a mean of 11.6 years. Setting: University hospital. Results : Left ventricular mass index and relative wall thickness were slightl y greater in patients in the highest diastolic or systolic blood press ure stratum than in WHO stage II hypertensives, but these results were statistically non-significant, High peripheral resistance index was b est identified by diastolic blood pressure level. Receiver operating c haracteristic 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 resi stance. During follow-up the proportion of patients who had a clinical event or died increased with increasing severity stratum in ail three clinical classification systems, but the trends were statistically no n-significant, Risk stratification by echocardiographic left ventricul ar mass index was most successful in identifying patients at very high and very low risk of subsequent morbid events and all-cause mortality . Conclusion: Classification of hypertension severity by blood pressur e level has similar, although limited, effectiveness at a lower cost t han the WHO criteria in identifying patients with adverse cardiac chan ges and an impaired long-term prognosis. Echocardiographic measurement of left ventricular mass index was more successful than other classif ications in predicting subsequent morbid events.