A study of patients taking medication to control blood pressure has found that those whose readings vary significantly could be at greater risk of heart attack and stroke than those with high blood pressure readings and low variability.

An article published by the European Heart Journal details Imperial College London (ICL) analysis of data from a 20-year study of more than 8,000 UK patients with hypertension.

The article noted that clinical practice, based on current guidelines, dictates that treatment decisions in patients with hypertension are determined by levels of systolic and diastolic blood pressure – the higher and lower numbers of blood pressure readings respectively.

‘Our studies, however, provide robust evidence that visit-to-visit blood pressure variability is a far more powerful determinant of cardiovascular outcome and that at least half of all cardiovascular events in our cohort occurred in those with controlled blood pressure but high blood pressure variability,’ the article added.

As a result, the researchers have called for medical guidelines to be changed to take into account interventions where a patient’s blood pressure varies between readings.

The ICL team also highlighted that the drug amlodipine proved effective in lowering blood pressure variability during trials and could help to reduce risk.

Bryan Williams, chief scientific and medical officer at the British Heart Foundation, said: ‘The study suggests that monitoring blood pressure variability could be a vital addition to routine health checks, helping to spot patients who remain at risk despite appearing to have well-controlled blood pressure.

‘The challenge identified by this study for the future, is how to reduce blood pressure variability and smooth the blood pressure profile, beyond the lowering of blood pressure itself which we know is protective against heart attack and stroke.’