Understanding the Role of Gender in Cardiac Care
Women under 65 are two to three times more likely to die in hospital after a heart attack than men of the same age and Dr. Susanna Mak, a cardiologist and Director of Mount Sinai’s Mecklinger Posluns Cardiac Catheterization Research Laboratory wants to know why. Performing sophisticated tests in a cutting-edge lab – using catheters placed in the heart’s main chamber -- to directly measure key differences in heart pumping action between women and men is one way that she is conducting this transformative research.
Her research is aimed at tailoring treatment to gender and saving the lives of about 35,000 women admitted to hospital for heart attacks in Canada each year. Dr. Mak is the only researcher in the world doing these types of measurements.
Dr. Mak has discovered that women don’t have as many compensatory mechanisms to restore or increase blood flow after a heart attack. If the heart is injured, increasing heart rate to boost the heart’s ability to pump blood doesn’t work very well in women. She did complex measurements, comparing heart function in both sexes, to pinpoint the reason. “A woman’s heart doesn’t fill as well with blood between beats as a man’s heart. Filling the pump is as important as pumping when blood supply is cut during a heart attack,” says Dr. Mak, who also found women maintain about 40% higher levels of adrenaline to the heart than men.
She is now investigating the best ways of tailoring treatment to compensate for these differences, so more women will survive and recover from heart attacks. “If we could decrease the in-hospital mortality rate in women under 65, this would have a major impact,” says Dr. Mak, the recipient of a New Investigator Award from the Heart and Stroke Foundation of Canada.
A new and exciting area of research launched this year by Dr. Mak includes a study on the impact and benefits of exercise on the heart with aging. In collaboration with Dr. Jack Goodman, a leading University of Toronto exercise physiologist, she will use advanced imaging and catheter technology to measure changes in heart function during continuous exercise. “We hope to develop exercise training prescriptions for the heart that could delay some of the physical limitations of aging.”
Dr. Mak translates her extensive body of knowledge gained from her research to directly impact the way that she delivers care to her patients. For example, as a cardiologist with Mount Sinai’s Anna Prosserman Heart Function Clinic, she is able to use the cath lab’s advanced diagnostic procedures to tailor therapy for patients with various stages of congestive failure and better assess their eligibility for a transplant, or a heart assist device. Her lab recently became the centre for investigation and treatment for the heart failure and transplant program at both Mount Sinai Hospital and the Toronto General Hospital.