MRI reduces heart surgery rates for angina treatment
A simple MRI scan of patients with angina was just as effective as invasive angiography and can reduce the number of patients needing cardiac surgery.
According to a new study. published in the New England Journal of Medicine. the management of the care of patients with stable angina is based on a reduction of risk factors and medical therapy; if the condition is severe, patients undergo a procedure to improve blood flow to the heart called revascularization.
There are two strategies used to determine whether a patient with stable angina needs revascularization—either a cardiovascular MRI or invasive angiography, which is a medical imaging technique to measure pressure differences in the heart, called fractional flow reserve. The angiography typically involves injection of a contrast agent and requires a hospital stay.
The researchers, from several different countries, looked at 918 patients with angina and risk factors for coronary heart disease and divided them into two groups. The first group received standard invasive angiography. The patients in the other group had a 40-minute myocardial-perfusion cardiovascular MRI scan of the heart to see if the patient needed invasive angiography. The research was conducted at 16 sites in the United Kingdom, Portugal, Germany and Australia.
Both groups had similar outcomes, with fewer than 4 percent in both groups having cardiac events, such as a heart attack, in the following year.
But the group whose treatment was dictated by the MRI scan had significantly fewer angiographies and coronary revascularizations. Only 40 percent of patients receiving the MRI scan went on to have invasive angiography, compared with 96.8 percent of patients in the standard invasive angiography group. Moreover, only 36 percent of the MRI group ended up having revascularization, compared with 45 percent in the angiography group.
“Personalizing patients’ treatment for angina will mean that we can target the more invasive treatments only to those patients that really need them….[It] could mean that patients' initial visits to hospital are quicker and more patient friendly, and that they are less likely to have further procedures. But crucially the outcomes for patients of taking this approach were similar, so there is no negative impact of directing treatment in this way only to those we're sure need it,” said lead researcher Professor Eike Nagel, a consultant cardiologist and chair in Clinical Cardiovascular Imaging at King’s College London.