P-329: 1999 WHO/ISH risk stratification for hypertension applied to the 1999 MONICA-sample from Northern Sweden

Treating hypertension with drugs is so far the only reliable way to reduce this important risk factor for cardiovascular disease (CVD). It is important to determine absolute risk, and thereby estimate indication for drug treatment, in order to maintain a cost-effective drug treatment. The aim was to study consequences of the recent WHO/ISH risk stratification scheme on a random sample from a geographically defined population, regarding indication for treatment, target blood pressure, and cost. WHO/ISH Hypertension Guidelines from 1999 propose a risk stratification for estimating absolute risk for CVD. WHO multinational monitoring of trends and determinants in cardiovascular disease (MONICA), was initiated during the eighties and Northern Sweden is one of the populations. In 1999, 5 997 persons were screened for cardiovascular risk factors. We have risk classified each of these patients by a computer programme according to the WHO/ISH scheme. However, the blood pressure was only measured on one occasion (mean of two measures). Left ventricular hypertrophy was not recorded in this MONICA sample. Results: In all, 917 (15%) had drug treated hypertension. Three quarters (n=714) were inadequately treated with blood pressure levels above the cut of for initiating treatment in their respective risk group. 1773 (30% of 5 997) untreated subjects had a blood pressure of 140/90 or above; 16% in the low, 62% in the medium, 8% in the high, and 14% in the very high risk group. The corresponding risk group pattern for the inadequately treated hypertensives (n=714) was 10%, 47%, 10%, and 33%, respectively. If we shift the target blood pressure from below 140/90 to below 130/85 for drug treated subjects under 60 (n=278) the number inadequately treated raises with 34 subjects (3.7% of 917, 12.2% of 278); 14 in the low risk group (mean age 51.6, cholesterol 5.5 mmol/l, no smoking or family history of cardiovascular disease), 15 in the medium risk group, and only 5 in the high or very high risk groups. Conclusion: In this recent MONICA sample, 15% had hypertension, which in more then 75% was inadequately treated. A further 30% had untreated high blood pressure. Very few of the inadequately treated hypertensives were in the low risk group and more than 40% had a high or very high risk of CVD. If the blood pressure goal was lowered from below 140/90 to below 130/85 mm Hg, as WHO/ISH suggested, the number of inadequately treated subjects increased marginally and mostly with low r