Hundreds of people with angina may be unnecessarily undergoing angioplasty -- a common procedure to clear clogged coronary arteries that carries a small but real risk of heart attack and stroke -- because drugs alone work just as well, Canadian researchers are reporting.
The study challenges the conventional thinking that angioplasty provides more freedom from chest pain than medication.
Researchers from the Institute for Clinical Evaluative Sciences and Toronto's Sunnybrook Health Sciences Centre could find no significant differences in symptoms between patients treated with angioplasty and those treated with modern-day drug therapy alone.
The benefit of the popular procedure on angina relief "may be substantially smaller than previously believed," the team writes in a study published today in the Annals of Internal Medicine.
Over the past decade, the number of angioplasties performed in Canada has more than doubled. In 2007-08, 35,700 procedures were performed in Canada, outside of Quebec, according to the Canadian Institute for Health Information. Numbers for Quebec were not available.
Angioplasty uses a balloon to open narrowed or blocked arteries, and stents -- tiny, cage-like tubes or scaffolds -- to keep arteries propped open. It has become the favoured treatment for heart attacks and angina.
Although recent studies have shown angioplasty doesn't reduce deaths or heart attacks in patients with stable coronary artery disease -- meaning patients who aren't in the midst of a heart attack -- it's long been thought to provide more comprehensive relief of angina than drugs alone.
"Intuitively, it makes a lot of sense that it should make people feel a lot better, and people should do better after it," said lead author Dr. Harindra Wijeysundera, a staff cardiologist at Sunnybrook. "But it had never been studied (for symptoms relief) in any kind of systematic fashion."
The Toronto team searched medical literature for the best studies they could find that spanned the angioplasty era from 1990, to 2009. The study included 14 separate trials that enrolled 7,818 people.
But when the researchers focused on the more recent trials -- those done since 2000 -- "we didn't find a difference between the patents who were treated with medical therapy and angioplasty, versus just medical therapy," Wijeysundera said.
"At no point did we find that angioplasty doesn't work,"he said. "However, there is a caution that says medical therapy is actually really, really good, and many patients appear to improve, as far as their symptoms, just with medical therapy."