Doctors need to consider the variability in readings to determine a patient’s risk of stroke and their treatment
THE REPUBLIC'S leading blood pressure expert has called for changes in the way doctors manage the condition, following the publication of a series of landmark papers on blood pressure control in the Lancetmedical journal last weekend.
Prof Eoin O’Brien, professor of Molecular Pharmacology, the Conway Institute at University College Dublin (UCD), and vice-president of the Irish Heart Foundation (IHF), said that the discovery of a link between variation in systolic blood pressure and the risk of having a stroke means that doctors will now have to consider how much variability there is in blood pressure readings during a series of visits by a patient.
This is in addition to the current practice of monitoring a patient’s blood pressure readings and treating any sustained rise in average blood pressure.
How then do we take account of blood pressure variability in practice? Detecting variability appears easy in retrospective studies, such as those reported in the Lancet, but this is not readily done in practice.
"Improved methods of collecting data electronically so as to detect trends in blood pressure in the office and home and the increased use of ambulatory blood pressure monitoring are methods that should be more widely available," Prof O'Brien told The Irish Times.
Ambulatory blood pressure assessments, also known as 24-hour blood pressure monitors, are increasingly used to determine whether to treat a person’s blood pressure or not.
They were developed in order to avoid treating people with “white coat” hypertension, a condition in which a person’s blood pressure rises simply because they are in hospital or at their local surgery.
In addition, the technology can pick up those whose blood pressure may only be out of control at certain times of the day, but whose readings can reach excessively high levels despite being relatively normal during routine medical appointments.
The Lancetpapers, based on work carried out by researchers at Oxford University, showed that blood pressure variability, even in patients showing normal average blood pressure, is an independent predictor of suffering a stroke.
Prof O’Brien said there were already positive developments in treatment options for a person with high visit-to-visit blood pressure variability.
The use of a “flexipill” allows the prescribing of low doses of two drugs in one tablet.
"The flexipill provides a means of not only lowering mean blood pressure but of also reducing blood pressure variability, thereby passing on to our patients the benefits of the research reported in the Lancet."