A new study led by McMaster researchers may change the medical treatment of heart attack survivors.
The COMPLETE study, led by Dr. Shamir Mehta, staff cardiologist at Hamilton Health Sciences and professor with the Population Health Research Institute at McMaster University, investigates reducing survivor’s risk of future heart attacks.
Heart attacks occur when arteries supplying the heart with blood are blocked. Doctors typically open up the artery responsible for the heart attack and treatment proceeds with medications such as blood thinners, beta blockers and low-dose aspirin. The COMPLETE study, however, aims to investigate whether opening up more potentially problematic arteries is preferable to medication-focused treatment options.
“Given its large size, international scope and focus on patient-centered outcomes, the COMPLETE trial will change how doctors treat this condition and prevent many thousands of recurrent heart attacks globally every year,” said Mehta in a McMaster press release regarding the study.
Arteries are “opened up” through a procedure known as percutaneous coronary intervention, a non-surgical procedure in which a small structure known as a stent is put in place to widen blood vessels supplying blood to the heart. Blood vessels that require this procedure are usually narrow due to a buildup of plaque.
Beginning in 2013, the COMPLETE study has enrolled over four thousand patients with acute heart attacks from 31 countries. Upon arriving at collaborating hospitals, patients are quickly installed with a stent to widen the narrowed artery. If cardiologists discover one or more arteries that are more than 70 per cent blocked during the procedure, that patient becomes eligible for the COMPLETE study.
Patients are randomized to one of two groups: one returns 45 days later to install more stents while the other heads home with normal medication centered treatment.
The study found that 7.8 per cent of patients that had additional stents installed either had another heart attack or died. By contrast, 10.5 per cent of patients receiving conventional care experienced these outcomes.
“This study clearly showed that there is a long term benefit in preventing serious heart-related events by clearing all of the arteries. There was also no major downside to the additional procedure,” said Mehta.
The COMPLETE trial earned international attention after being published in the New England Journal of Medicine early last week, and was presented at the World Congress of Cardiology in Paris. Whether the study’s findings will convince more doctors that partially occluded arteries should also be opened up, or result in a change in medical practices remains to be seen.
The study may prove to be of special importance to Canadians. Heart disease is the second leading cause of death in Canada and cardiovascular diseases account for approximately 30 per cent of all deaths worldwide. Making changes to improve the treatment of patients with multivessel disease may help to save lives in the future.