Low BP may increase the risk of stroke or MI among patients with coronary artery disease (CAD), US research suggests.
The study, presented earlier this month at the American Society of Hypertension annual meeting in San Francisco, involved 10,000 men and women randomly assigned to receive either atorvastatin 10mg or 80mg.
The participants were aged 35 to 75 and had CAD and LDL cholesterol less than 130mg/dL.
The research team, led by Dr Franz Messerli from St Luke's-Roosevelt Hospital in New York, found that the risk of suffering a major cardiovascular event increased by 3.1-fold among patients with a low systolic BP, less than 110mmHg, compared with patients with a normal systolic BP.
Patients with a low diastolic BP, less than 60mmHg, had a 3.3-fold increased risk of cardiovascular events.
The researchers suggest that the findings show that lowering BP too much can be harmful.
Berkshire GP Dr George Kassianos, a member of the British Cardiology Society, said: 'This study has implications in the way we manage hypertension in primary care, in patients who have CAD.
'If patients with CAD have too low a diastolic BP, then this may limit coronary perfusion and increase pulse pressure, which may affect the endothelial function.'
Dr Kassianos advised a safe diastolic BP of around 70mmHg for patients who have CAD.
'Anything lower than this level and it could compromise the patients' myocardial perfusion,' he warned.
But North Yorkshire GP Dr Terry McCormack, former chairman of the Primary Care Cardiovascular Society, said: 'It's a chicken and egg situation. It is unclear whether low BP is actually causing the cardiovascular events or just associated with them.'
'It is unlikely that we would be treating to the low BP targets achieved in the study in primary care anyway,' he added.
Comment below and tell us what you think