At the 2014 Canadian Cardiovascular Congress and American Heart Association Scientific Sessions, Heart Institute researchers presented several studies that tested novel ways to visualize the heart’s structure and function.
Developing methods to predict which plaques in the arteries may be at high risk for rupture, thereby causing a heart attack, is a priority for cardiovascular researchers. At the two meetings, a team led by Rob Beanlands, MD, presented a study showing that a type of positron emission tomography (PET) imaging could identify blood vessel plaques with active calcification, which may be a marker for plaques at risk of rupturing.
Another group led by Dr. Beanlands reported on findings comparing PET to other diagnostic technologies for guiding treatment after a heart attack. The five-year follow-up data from the PARR-2 trial suggested that PET may be better than other tests for helping doctors decide whether surgery or drug therapy is best for individual patients.
A team led by Ian Burwash, MD, discussed a simplified approach to measuring left ventricular ejection fraction (LVEF). Ejection fraction is the percentage of blood pumped from the heart with each heartbeat. LVEF is a standard measure of how effectively the heart is pumping. It provides prognostic information about a patient’s future health and helps guide physicians in deciding which medications or devices will be most beneficial. Nuclear medicine tests can accurately measure LVEF but require exposing patients to a small dose of radiation.
A method exists for measuring LVEF with echocardiography, which doesn’t use radiation but is based on visualizing all the walls of the heart at once. This requires significant physician expertise and is not possible in all patients. The method proposed by Dr. Burwash and his colleagues evaluates the function of individual heart segments separately. “By adding up the function of all the individual heart segments,” explained Dr. Burwash, “we can obtain a measure of the overall heart function.”
In a study of 186 patients, the simplified technique produced results similar to a nuclear medicine test and was as accurate as the more complicated echocardiography technique. “We think the simplicity, ease of use and accuracy of this new method makes it a perfect tool to measure LVEF, especially in centres without highly experienced echocardiographers,” said Dr. Burwash.