Solving the mysteries of heart surgery

St. Michael’s Hospital, cardiovascular surgeon Dr. Subodh Verma was troubled by the lack of data to guide decision making and treatment choices for patients undergoing heart or vascular surgery.

“There are still too many unknowns when it comes to cardiovascular surgery outcomes,” says Dr. Verma. “I think the best way to find those missing links is by connecting smart people and asking smart questions.”

Dr. Verma formed a research hub, called CARDIOLINK, to answer questions that will improve care and prevent hospitalization for patients with heart and vascular disease or diabetes.

CARDIOLINK brings together top experts from across St. Michael’s, Canada and the world to address five major themes of cardiovascular surgery: atrial fibrillation, aortic aneurysms, peripheral arterial disease, valvular heart disease and community-based interventions to reduce re-hospitalization.


“For each of our five themes, there is a randomized clinical trial being developed – each designed to address an important gap in cardiovascular research and deliver definitive and potentially practice-changing results,” says Dr. Verma.

The SEARCH-AF trial will investigate whether using a new heart rhythm monitoring device after heart surgery will uncover new rhythm irregularities and help identify individuals at risk of having a stroke following heart surgery.  This trial is funded and underway.

The ACE trial is aimed at comparing strategies to protect the brain when surgeons need to cool the body and stop blood circulation during complex aortic surgery. Dr. Verma says brain protection is the Achilles’ heel of aortic surgery and ACE will help answer whether a new technique—developed at St. Michael’s—is safe for patients undergoing these operations.

Critical limb ischemia is a serious problem that affects patients with peripheral arterial disease. It carries a high risk of limb amputation and a 50 per cent chance of dying within five years. CARDIOLINK has developed the EXTINGUISH trial to test whether an anti-inflammatory medication can reduce rates of death in patients with critical limb ischemia.


The CAMARA-1 trial will compare two different ways to repair the mitral valve to see whether one is better at improving the functional capacity of patients and restoring them to more meaningful lives.

The ENABLE-NP study will try to find better ways to meet the complex needs of vulnerable patients by engaging their communities. It will evaluate whether interventions delivered by nurse practitioners in the community can reduce rates of re-hospitalizations after peripheral artery surgery.

In creating CARDIOLINK, Dr. Verma teamed up with cardiovascular anesthesiologist, Dr. David Mazer, and Dr. Muhammad Mamdani, director of the Applied Health Research Centre.

Several other members of St. Michael’s are leading or involved in individual CARDIOLINK themes.  Dr. Mark Peterson is working on the ACE trial; Dr. Mohammed Al-Omran on EXTINGUISH, Dr. Howard Leong-Poi on CAMARA-1 and Dr. Akshay Bagai on ENABLE-NP.  CARDIOLINK includes representation from Calgary, Hamilton, Ottawa and London, Ont., as well as Saudi Arabia and Australia.