Rural patients often had to be sent to a larger hospital for angioplasty. (CBC)

Time to treatment, not the type of therapy used, is key to restoring blood flow following a heart attack, a new Quebec study shows.

The research, published Wednesday in the Journal of the American Medical Association, suggests getting treatment within the recommended window is more important than whether that treatment is a shot of clot-busting drugs or an angioplasty procedure to open a blocked artery.

The findings inject some real-world practicality to what has been the growing belief that angioplasty is the preferred option after a heart attack. That belief has arisen from randomized controlled trials, where the two techniques were tested head-to-head under optimum conditions.

"Because of randomized trials, there is a perception that angioplasty is better," lead author Laurie Lambert of Quebec's health technology and health services evaluation agency said in an interview.

"But the randomized trials don't have delays that we see in the real world. So that's the big issue."

Lambert and her co-authors conducted what is called an observational study, looking at the results of six months worth of heart attack responses at 80 Quebec hospitals.

All hospitals that treated more than 30 heart attacks during that period were included in the study, which covered the period from October 2006 to the end of March 2007.

Time targets missed

Of 1,832 patients who received one of the two treatments, 21 per cent got clot-busting drugs while 79 per cent underwent angioplasty, a procedure where a tiny balloon is snaked into the affected artery and then inflated to release the blockage.

For maximum benefit, the former is meant to be administered within 30 minutes of arrival at hospital while the latter should be done within 90 minutes of hospital arrival.

But those time targets were not reached in 54 per cent of patients treated with clot-busting drugs and 68 per cent of those given angioplasty.

Only 15 of the 80 hospitals had the capacity to do the angioplasty, meaning many patients who underwent the procedure had to be transported from the community hospital where they first sought care to a larger hospital in an urban centre.

Quick drug treatment

The rate of deaths or readmission to hospital within a year was virtually the same for the two groups, 13.5 per cent. But the patients who received treatment late — either treatment — were twice as likely to die within 30 days as those who were treated within the recommended window.

"It's better to give either of the options quickly than to delay giving one treatment in order to give the other treatment," said Dr. Jack Tu, a senior scientist with the Institute for Clinical Evaluative Sciences in Toronto.

"You're better off to give lytics" — clot-busting drugs — "quickly than to give primary angioplasty in a delayed manner."

Tu was not involved in the study, but has done similar work looking at the situation in Ontario. The findings, not yet published, back what Lambert and her colleagues saw, he said.

"What this shows is that in a real world setting, the outcomes are probably pretty similar at one year, regardless of how you're treated," he said. "So what's more important is speed than the modality."

That is a critical piece of knowledge in a country like Canada, where a small population is stretched across a wide geographic expanse.

"You're not going to have a cath[ether] lab in every hospital," Lambert said.

Tu noted that in densely populated Britain, health authorities aim to treat the vast majority of heart attack patients with angioplasty and to do it within the recommended time, which is easier and more feasible to do in such a geographically dense area.