Research announced Tuesday suggests that a drug-coated coronary stent from Johnson & Johnson ( JNJ) "may be superior" to a rival stent from Boston Scientific ( BSX) in certain high-risk cases.

However, the research, to be published in the Jan. 12 Journal of the American Medical Association, carries a number of qualifying statements. The authors say their findings relate to a narrow area of artery problems for a "high-risk subset" of patients who received J&J's Cypher or Boston Scientific's Taxus stents.

Using terms like "suggest" and "may," the authors say a much larger head-to-head trial that is now under way with other researchers will be the key statistical showdown between Cypher and Taxus. Results of this other study, sponsored by J&J, are due to be presented at a meeting of the American College of Cardiology in March.

The JAMA study was conducted by German hospital researchers and financed by a German university-based hospital. They originally presented their findings at a cardiology conference in Munich in September.

Drug-coated coronary stents are wire mesh tubes inserted into arteries after patients undergo a procedure known as angioplasty to clear artery-clogging plaque. Angioplasty involves the insertion of a balloon-tipped catheter through an artery in the groin or arm. When the catheter reaches its target vessel, the balloon is inflated to unblock the obstruction.

Stents facilitate the flow of blood. Drug-coated stents, also known as drug-eluting stents, periodically release chemicals into vessels. Drug-coated stents do a better job of preventing the subsequent narrowing of arteries than angioplasty alone or than the insertion of uncoated, or bare metal, stents after angioplasty.

It's this renarrowing, or restenosis, of arteries that attracted the attention of the German researchers. They looked at patients who had received bare metal stents and whose arteries had become narrow because of the buildup of scar tissue.

They tried to determine the best remedy for reopening the arteries: angioplasty alone, insertion of Cypher, or insertion of Taxus. Angioplasty has been the first-line treatment for this arterial renarrowing known as in-stent restenosis, which affects 20% to 40% of bare-metal stent recipients, the JAMA article said. However, results from angioplasty alone "have often been disappointing with a recurrence rate above 40%."

Researchers tested 100 patients for each of the three remedies. They found that patients receiving either a Taxus or Cypher had much less arterial renarrowing than did patients who simply underwent angioplasty.

They also found that there was a statistically significant difference between the number of Cypher patients (eight of 100) needing to have their arteries unclogged again vs. the number of Taxus patients (19 of 100) needing the procedure.

The researchers said that although this Cypher vs. Taxus comparison was "not part of the primary analysis," the results "suggested that there may be differences" between these stents in their "prevention of recurrences" in patients with a high risk of experiencing reclogged arteries.

The authors noted that "the definitive answer" will come from the J&J-sponsored clinical trial, nicknamed REALITY, which is testing 1,386 patients. In addition to being a much bigger study, REALITY is looking at how well Cypher and Taxus prevent initial reclogging of arteries after the original treatment. REALITY's results will affect more potential patients than the results of the German study.