[img_inline align=”right” src=”http://padnws01.mcmaster.ca/images/mehta2.jpg” caption=”Shamir Mehta, associate professor of medicine at McMaster, is lead investigator of a study that settles the question of how long patients with mild heart attacks should wait before undergoing angioplasty. File photo. “]McMaster University researchers have settled the question of how long patients with threatened or mild heart attacks should wait before undergoing angioplasty or bypass surgery.

In their study published in today's New England Journal of Medicine researchers found similar rates of death, recurrent heart attack or stroke in patients allocated to receive an invasive procedure very early after they arrived in hospital versus if they had their procedure a day and a half or more later. However, a sub-group of patients (one out of three) who were at high risk of having another event did appear to experience a benefit if they underwent an early intervention.

“This is good news for patients and physicians,” said the study's lead investigator Shamir Mehta, an associate professor of medicine in the Michael G. DeGroote School of Medicine.

“While we have known for a long time that patients with a full blown heart attack benefit from receiving angioplasty as early as possible, we did not know the optimal timing of angioplasty in patients with threatened or smaller heart attacks,” said Mehta. “These second group of patients represent a large burden to the health care system and outnumber patients with full blown heart attacks by about 2:1. They often respond well to initial therapy with aspirin and other anti-clotting medications.”

The question of optimal timing has important implications for the organization of advanced cardiac facilities in Canada, where geography can often impede ability to get patients into a center that does angioplasty in a timely fashion.

“In large parts of Canada that do not have timely access to these procedures, patients coming to hospital with small or threatened heart attacks can be treated with aspirin and other anticlotting medications and be transferred to a catheterization laboratory a few days later without undue harm. Higher risk patients and those with full blown heart attacks should still be transferred earlier,” Mehta said.

The Canadian-led global study was funded by the Canadian Institutes of Health Research (CIHR).