What’s a Heart Patient to Do?

The two new studies, however, can. The first of them is a head-on comparison of drug-eluting stents and CABG, which is the standard of care for complex coronary artery disease. Judging by the data, CABG shouldn't be unseated from that position; in many ways it's a better option than the drug-eluting stents. After 18 months patients in the New York databases who underwent the surgery needed fewer follow-up procedures. "With surgery you're most likely to treat all the arteries that are blocked," explains Spencer King, a past president of the American College of Cardiology and chairman of the New York state board that oversaw the new studies. "With stents you can have patients who only get one vessel opened, and later the symptoms will still be there." Patients who underwent CABG in the study were also less likely to die or have heart attacks, although the difference was "not whopping," says Marroquin—it was only about 2 percent.

The second study, unlike the first, does lend some support to the use of drug-eluting stents. It compares them not to CABG but to another option for treating coronary artery disease: bare metal stents. Here, drug-eluting stents are the winners: they're "as safe and more effective than bare metal stents in patients who have complex heart disease," says Marroquin, who led the study.

It's easy to assume that the studies suggest a clear hierarchy: CABG is better than drug-eluting stents, which are better than plain stents. That's largely true. But patients may still have a few reasons to keep drug-eluting stents in mind over CABG. Chief among them is the fact that bypass surgery is, well, surgery. The in-hospital mortality rate—in other words, the short-term risk—is higher for CABG than it is for the stents, although the risk evens out with time. "CABG is more invasive, so there are more things that can go wrong at first," says Hannan. "If nothing does go wrong, the surgical treatment has more promise for lasting a longer period of time—provided that the patient doesn't suffer a major complication during surgery and die."

There's also one group of patients who still should look at the third option, bare-metal stents: those who can't take clot-busting drugs. One such medication, Plavix, is usually administered before a drug-eluting stent is inserted. Patients who have a high risk of internal bleeding, or who are scheduled to undergo other surgeries, shouldn't take Plavix; bare metal may be their best bet.

Even though the new research is solid, it does not answer all the remaining questions about drug-eluting stents. Both papers are "observational" studies; they are not randomized controlled clinical trials, the gold standard for scientific research. Such trials of stents are difficult to conduct, says Joseph Carrozza, a cardiologist at Beth Israel Deaconess Medical Center in Boston who wrote an editorial accompanying the new studies. Potential patients are reluctant to enroll in trials when their lives may be on the line. "They have to be eligible for both stents and CABG," he says, "and most people don't want researchers making that decision for them based on the flip of a coin."

Wednesday's studies have also given researchers new questions to answer. Surprisingly, says Hannan, the CABG-versus-stent study showed that diabetics did equally well with bypass surgery and drug-eluting stents. Other studies have found that diabetics benefit more from surgery, even more than healthier patients do. "That issue definitely needs some further research," says Hannan.