[Blood pressure goals on the test bench]

Abstract

There is little evidence from controlled prospective studies to support the low blood pressure goals stipulated for the treatment of hypertension by present guidelines, especially in high-risk patients with diabetes, renal insufficiency or coronary heart disease. Aim of this review is to scrutinize the potential benefit and risk of low blood pressure on the basis of recent studies and secondary analyses of older studies.

Results: In patients with coronary heart disease or equivalent or with diabetes lowering systolic blood pressure to 130 to 135 mmHg reduced primary or secondary cardiovascular endpoints in the majority of studies. Between 120 and 129 mmHg some positive effects could be shown in patients with coronary heart disease but not in patients with diabetes or metabolic syndrome. In patients with diabetic or nondiabetic nephropathy including those with proteinurea no convincing data exist which show a better outcome with systolic blood pressure below 130 versus below 140 mmHg. However, several studies suggest that the risk of stroke may decrease by lowering systolic pressure to 120 mmHg or even lower. Below 120 mmHg an increased risk of cardiac and noncardiac events or death was shown in quite a number of studies. In patients between 70 and 80 years, current evidence suggests lowering systolic blood pressure to 135 to 145 mmHg and in those above 80 years to 145 to 155 mmHg. No evidence was found to justify different diastolic pressure goals for different groups of patients; optimal values fall between 70 and 85 mmHg. Limitations of recent studies are short follow-up, few event rates and small differences in achieved pressure between groups leaving uncertainty about long-term effects.

Practical consequences: Apart from prevention of stroke there is sparse evidence that lowering systolic blood pressure below 130 mmHg may be beneficial. Current evidence suggests that lowering systolic and diastolic pressure into a range of 130 to 140/70 to 85 may be adequate for all patients with the exception of children, adolescents and patients over 80 years. Further lowering of systolic pressure seems to offer little additional benefit and lowering diastolic pressure below 70 mmHg might increase risk.