Taking a closer look:

Dr. Imtiaz Ali explores and questions common practices in cardiac care
Cardiac surgeon Dr. Imtiaz Ali thrives on taking a closer look at widely used methods and medications of cardiac care. He questions several common practices, and hopes his clinical research will lead to larger studies that show conclusively which practices help and which ones may harm.

Dr. Ali points to the widespread use of nitroglycerin pills to control angina, chest pain caused by reduced blood flow to the heart. Population studies show that people who regularly take these pills to control stable angina tend to die sooner than those who don’t.

“Nitroglycerin relieves chest pain and is useful in acute situations, but long-term use damages the cells that line the arteries,” explains Dr. Ali, assistant professor in Dalhousie Medical School’s Division of Cardiac Surgery and a member of the Cardiovascular Research Group. “This can lead to inflammatory build-up that increases the risk of heart attack or stroke.” He wants to know if intravenous nitroglycerin – often given before, during and after heart surgery – has a negative or positive effect on how patients fare in hospital.

Dr. Ali and colleagues at the Maritime Heart Centre are using a comprehensive database to explore this and other questions. “In 5,000 heart surgery patients, we’ve been unable to show that cholesterol-lowering drugs called statins improve patient outcomes,” he says. Dr. Ali also wants to know if correcting certain pre-existing arrhythmias – during open heart surgery for other conditions – provides benefits that outweigh the risks.

When he’s not in the clinic or operating room, Dr. Ali is in the lab, working with basic scientists to learn why insulin has such a powerful protective effect on the heart. Patients often receive insulin after a heart attack, and it is always given during heart surgery, when the heartbeat is stopped. “We’ve found that insulin protects against ischemic injury by stimulating production of heat shock proteins,” says Dr. Ali. “We’re looking at the mechanisms in detail, to see if there is a way to enhance insulin’s protective effects.”