The number of Canadians having blocked heart arteries opened with a non-surgical procedure more than doubled between 1994 and 2005, mirroring trends seen in the U.S., Europe and elsewhere, according to a new study.

It is unclear whether the increase reflects appropriate use of the procedure, called angioplasty, or has been “too great” - or possibly not great enough - said lead researcher Dr. Ansar Hassan, of Saint John Regional Hospital in Canada.

During angioplasty, a balloon-tipped catheter is threaded into a clogged artery to push blockages aside; usually a small mesh tube called a stent is placed in the artery to help keep it from re-narrowing.

For the study, published in the American Heart Journal, Hassan and his colleagues looked at government data on all cases of angioplasty and heart bypass surgery - another option for treating blocked heart arteries - across Canada.

They found the rate of angioplasty increased from roughly 86 procedures per 100,000 people in the population in 1994, to 187 per 100,000 in 2005. At the same time, rates of bypass surgery remained fairly stable - at about 76 per 100,000 in 1994 and 71 per 100,000 in 2005.

That trend is similar to what has been seen in the U.S. and other countries, Hassan told Reuters Health in an email - though, he added, the angioplasty-to-bypass ratio may differ from region to region.

Hassan pointed to a recent study showing the rate of elective angioplasty among patients with a past heart attack was twice as high in New York state as in the Canadian province of Ontario, while rates of bypass surgery were comparable.

In the current study, rates of angioplasty in 2005 varied from province to province - from a low of 114 per 100,000 in Alberta, to 229 per 100,000 in Quebec. Ratios of angioplasty to bypass surgery also varied among provinces.

The reasons for the overall shift in angioplasty rates are not clear from this study, but it is unlikely that a change in actual heart disease patterns in the population is at work, according to Hassan.

Potential factors, he and his colleagues speculate, include advances in stent technology, such as drug-coated stents, which help lower the risk of artery re-narrowing versus traditional bare-metal stents.

In addition, patients may often prefer angioplasty to bypass surgery, as it is less invasive and has a shorter recovery time.

Doctors’ preferences may also be at play. Unlike bypass surgery, which is the realm of cardiac surgeons, cardiologists with the appropriate training can perform angioplasty. That may sway their likelihood of referring patients for surgery.

Hassan also pointed to the possible role of financial pressures, such as trimming patients’ hospital stays by opting for angioplasty over bypass.

Angioplasty can be live-saving when used to re-open coronary arteries during a heart attack. It may also be the best treatment option for some people with unstable heart disease, where symptoms like chest pain and breathlessness arise even when a person is at rest.

Less clear is the value of angioplasty for people with stable heart disease; recent clinical trials have suggested that for these patients, angioplasty may be no more effective than medication (such as aspirin and cholesterol-lowering statins) and lifestyle changes alone in reducing the risk of heart attack or death.

At the other end of the spectrum are patients with more severe heart disease, such as blockages in multiple coronary arteries. While angioplasty was originally used to treat only less extensive heart disease, technical advances over the years have allowed doctors to increasingly use the procedure for more severe cases.

However, bypass surgery may still be the better option in at least some cases of more extensive heart disease.

For patients with heart disease, Hassan’s advice is to ask questions about all treatment options, including sticking with medication and lifestyle changes alone.

“When patients with atherosclerosis are put forth for some form of revascularization procedure (angioplasty or bypass surgery),” he said, “I think it would be a good idea for them to ask their physicians about the benefits and risks of all invasive and non-invasive treatment options to them, regardless of whether angioplasty or bypass is being offered.”

SOURCE: American Heart Journal, November 2010.