The Wall Street Journal
Tuesday, May 4, 2004
In the past decade, angioplasty has displaced bypass surgery as the primary treatment for blocked coronary arteries. Angioplasty –sliding a balloon into the artery- is now done more than a million times a year in the U.S., compared with about 300,000 bypass surgeries. The reason is that angioplasty is minimally invasive, requiring a mere slit in the groin and one night in the hospital, as opposed to a cracking open of the chest for surgery, followed by five to seven days in the hospital and six weeks of recovery.
But a study to be published this month in the journal circulation concludes that coronary bypass surgery has longer-lasting benefits than does angioplasty-at least in the high-risk patients. In the study, researchers at the Cleveland clinic followed 6,033 heart patients for five years after surgery or angioplasty, and found the risk of death was more than twice as high in the angioplasty group.
The new research, which involves seriously ill heart patients, raises questions about the wisdom of the overwhelming trend toward angioplasty. It has broad implications for heart patients, their doctors and potentially, the medical device industry. An estimated 500,000 Americans each year die of coronary heart disease a condition that affects about 13 million people in the U.S. overall. Cleveland Clinic doctors estimate that at least 25% of them, or more than three million patients, are in the high-risk group the study discusses.
Past studies have shown angioplasty – which often involves placing a wire-mesh stent in a coronary artery – in comparable to surgery in avoiding deaths over time. And given that hospitals generally charge $23,000 to $30,000 for bypass surgery, versus $12,000 to $15,000 for angioplasty, physicians have increasingly recommended the less-invasive, less expensive angioplasty. This in turn has fueled a huge industry. Companies including Boston Scientific Corp., Guidant Corp, and Johnson & Johnson generated nearly $6 billion in worldwide sales in 2003, selling the angioplasty assembly of wires, balloons and catheters, as well as the mesh stents.
But some of those earlier studies suggested that diabetes patients with heart disease tended to have better survival with bypass surgery. Also, patients with significant heart failure - meaning a decrease in the hearts pumping power – were generally excluded from earlier studies comparing stents and angioplasty versus surgery. All this prompted the Cleveland Clinic to look more closely at higher-risk patients.
The study was limited to patients with “multi-vessel” blockages in two or more of the three coronary arteries, and additional health factors like diabetes or heart failure. Also, the surgeries were performed at a leading clinic where heart-surgery results are among the best in the world. To duplicate such results, a patient would have to look to a similarly high-caliber facility.
In the study, researchers analyzed high-risk coronary patients treated at the clinic from 1995 to 1999. Half had moderate to severe heart failure or diabetes. There were 931 deaths during the five years of follow-up. The patients hadn’t been randomly assigned to a treatment, but got the treatment their doctors recommended. Since the more severely ill patients tended to be referred to surgery, all cases were “risk-adjusted” for the severity of illness so that the two treatments could be fairly compared.
Authors of the study included cardiologists, interventional cardiologists who do angioplasty and stent procedures and heart surgeons.
The conclusion was that surgery “was associated with better survival” in “patients with multi-vessel coronary artery disease and many high-risk characteristics.” Specifically, death was 2.3 times as likely to occur among angioplasty/stent patients over five years as in surgery patients. About 70% of angioplasty patients got stents.
“On the basis of these date, if I’m facing a person with multi-vessel disease, I’m leaning toward surgery,” says Michael S. Lauer, a Cleveland Clinic cardiologist who does neither surgery nor angioplasty. In such risky patients, he says, “the concern is long-term life expectancy.”
Since the last case studied occurred in December 1999, it preceded the advent of drug-coated stents, which are designed to prevent tissue from growing into the coronary artery and re-blocking it. These new stents could conceivably make a difference in angioplasty survival rates for high-risk patients. But there’s no research yet directly on point, and in the view of the researchers, drug-coated stents wouldn’t likely change the results.
“I am not so convinced that they truly affect mortality,” says study co-author Sorin J. Brener, an interventional cardiologist who does angioplasty and stent procedures. “This result is surprising and certainly not what I was looking for. We were hoping to see the death rates identical.”
These new findings may stem from the nature of the two procedures and of the disease itself. Coronary disease means that fatty plaque is building at multiple points within arteries that supply blood to the heart. It is a diffuse disease, growing at numerous sites in coronary arteries and other vessels throughout the body.
In angioplasty, a thin wire with a miniature balloon on the end is snaked through the femoral artery in the groin, up the aorta and into the coronary artery. The balloon is then expanded, pressing the plaque against the artery wall and widening the pathway. Often, a wire stent is left at the site to keep the plaque from damming up the artery again. But buildups of plaque and clots can occur elsewhere throughout the coronary artery. And thus the artery can clog once more. The result can be a heart attack.
In bypass surgery, as the name suggests, the entire bad artery is bypassed. A section of artery or vein from elsewhere is used as a detour route to supply blood to the heart. Thus, if more blockage occurs in the original artery, it doesn’t much matter. “Bypass surgery really bypasses the problem,” Dr. Brener says.
Of course, to experience the advantage of surgery, the patient must survive the operation. Thus, it is essential for a patient to be treated by a skillful surgeon and cared for by top cardiac nurses.
For patients looking to receive the best surgical care, it makes sense to seek out a leading academic medical center. For instance, the Cleveland Clinic, which is unusual in that it publishes its data, last year, saw its dearth rate in bypass surgery fall to 0.6%. In 1995 to 1999, that mortality rate was slightly higher, though it dropped from about 1.8% to about 1.12% during those years. The national norm is about 3%, and is falling, according to Dr. Brener.
Beyond that, Toby Cosgrove, the Cleveland Clinic’s chairman of cardiovascular and thoracic surgery, recommends asking how many cases the surgeon handles annually and what his or her mortality rate is. He also recommends inquiring into whether the surgeon typically uses a stretch of artery, or of vein, to replace the coronary artery.
“Arterial grafts tend to do better than vein grafts, says Dr. Cosgrove. “Vein grafts get atherosclerosis and close over time. The more arterial grafts you use, the better.” The use of the saphenous vein, from the leg, is easier technically, in his view, but the trend is toward the use of an artery to replace blocked coronary arteries.