Drugs to prevent another heart attack do help patients to live longer if taken regularly, a new Canadian study suggests.

Each year, about 65,000 Canadians suffer a heart attack and nearly 20,000 die. The numbers are starting to decline, but doctors weren't sure if that was thanks to new medications or lifestyle changes.

Heart patients must continue to take their medications after they feel better, says study author Dr. David Alter.
(CBC)

It may seem obvious that drugs taken after a first attack help to prevent a second one, but until now, there was no real evidence.

"In the real world, we needed that information," said Dr. Beth Abramson of the Heart and Stroke Foundation. "This is real world proof that these drugs save lives."

Researchers at Ontario's Institute for Clinical Evaluative Sciences looked at 31,455 elderly heart attack survivors in the province and tracked their prescription refills between 1999 and 2003.

Patients taking statins and beta-blockers within the first year showed a significantly lower risk of dying. Heart patients' benefits depended on how faithfully they took their medications.

For those who took their drugs occasionally, the risk of dying was 12 per cent higher than for those who took them as prescribed, the researchers said in Wednesday's issue of the Journal of the American Medical Association.

Among those who stopped taking the drugs altogether or took the medications only rarely, the risk was 25 per cent higher.

Up to one-third of patients studied stopped getting their prescriptions refilled, including those in a control group who were prescribed calcium channel blockers. Evidence is lacking on whether this class of drug helps survival after a heart attack.

"It's a marathon out there," said study author Dr. David Alter of ICES in Toronto. "We just can't stop when you're feeling good. We have to continue these because the real advantages come down the stream."

The problem may be that patients need to take the medications for the rest of their lives, and many don't.

"You're almost taking more drugs than you're taking food," said Pat McNair, a two-time heart attack survivor in Halifax who also has diabetes. "So you think, 'I'm gonna quit taking those' and then you realize, well, if I don't take them then tomorrow something could happen."

For some, the costs of the drugs or their side-effects may be a deterrent, but doctors say the findings should convince patients there are consequences for letting prescriptions lapse.