Blood pressure treatment should be based on personal risk not minimum thresholds

High blood pressure, the leading cause of heart disease and stroke, affects more than one billion individuals worldwide, and kills 9.4 million people every year. The benefit of lowering blood pressure in patients with substantially raised blood pressures is well established. But uncertainty remains about whether to treat people with lower blood pressures or with previous disease, and which drugs to use. 

In this study, Professor Kazem Rahimi from The George Institute for Global Health at the University of Oxford in the UK and colleagues analysed the findings of 123 large-scale randomised trials comparing different blood pressure targets from January 1966 to July 2015.

They found that treatment with any of the main classes of blood pressure-lowering drugs significantly the reduced risk of major cardiovascular events, stroke, heart failure, and death proportional to the magnitude of the systolic blood pressure achieved. Overall, every 10 mmHg reduction in systolic blood pressure reduced the risk of death from any cause by 13%, the risks of major cardiovascular disease events and heart disease by about one fifth, and stroke and heart failure by about a quarter. Importantly, these reductions in disease were similar across a wide range of high risk patients including those with a history of cardiovascular disease, heart failure, diabetes, and kidney disease, irrespective of whether their blood pressure was already low (less than 130 mmHg) to begin with.

None of the five major drug classes examined was found to be better than another at protecting against cardiovascular events, with a few exceptions—an extra protective effect of calcium channel blockers in preventing stroke and diuretics in preventing heart failure, and the reduced effect of beta blockers in preventing major cardiovascular outcomes, stroke, and renal failure.

The authors conclude by calling for an urgent revision of current blood pressure-lowering guidelines, including those of NICE and the European Society of Hypertension, that have recently relaxed blood pressure targets from 130/85 mmHg to 140/90 mmHg. They also recommend a shift from rigid blood pressure targets to individualised risk-based targets, even when blood pressure is below 130 mmHg before treatment.

According to Professor Rahimi, 'Our findings clearly show that treating blood pressure to a lower level than currently recommended could greatly reduce the incidence of cardiovascular disease and potentially save millions of lives if the treatment was widely implemented. The results provide strong support for reducing systolic blood pressure to less than 130 mmHg, and blood pressure-lowering drugs should be offered to all patients at high risk of having a heart attack or stroke, whatever their reason for being at risk.'