Studies expand on strategies for coronary disease

Research unveiled at this year's European Society of Cardiology meeting could affect interventional strategies for treating coronary disease. Results from a U.K. multicenter trial indicate that early intervention is better than a wait-and-see policy for patients with partial vessel occlusion. Meanwhile, a Swiss team presented data questioning the cost-effectiveness of drug-eluting stents for revascularization.

Rupture of coronary plaques does not always block vessels completely, though patients may still suffer acute chest pain. Deciding whether and when to repair these partially occluded vessels has been a subject of considerable debate, according to Dr. Keith Fox, a professor of cardiology at the University of Edinburgh. He expects data from a randomized trial involving 1810 patients from 45 U.K. hospitals to settle the matter (Lancet, 2005;366:914-920).

Patients presenting with non-ST elevation acute coronary syndrome, typified by plaque disruption, thrombus formation, and microembolization, received either early intervention (895 patients) or conservative management (915). This translated into almost-immediate angiography and revascularization versus ischemia- or symptom-driven angiography.

Rates of death or nonfatal myocardial infarction were similar for both groups at one-year follow-up. After five years, however, far fewer patients randomized into the early intervention group had died or suffered a heart attack. The researchers concluded that prompt treatment had prevented 3.5 such adverse outcomes in every 100 patients.

The five-year data show that hazards associated with intervention are offset by long-term benefits, Fox said. This conclusion could not be drawn from previous studies that considered clinical outcomes after only one or two years.

"All of these patients, apart from the lowest risk group, will need to have angiography with a view to intervention and revascularization. These is the definitive, long-term data," he said.

A separate analysis comparing the cost-effectiveness of drug-eluting and bare metal stents suggests interventionists should stick with their existing practices when it comes to choosing technology.

Dr. Matthias Pfisterer and colleagues from the University of Basel in Switzerland assessed the clinical outcome and treatment costs for 826 consecutive patients requiring percutaneous coronary intervention and stenting. Patients were randomized to receive either drug-eluting (545 patients) or bare metal (281) stents (Lancet, 2005;366:921-929).

The team recorded an outcome of cardiac death, myocardial infarction, or target vessel revascularization after six months in 39 patients fitted with drug-eluting stents (7.2%) and 34 patients who received the bare metal stents (12.1%). They concluded that the relatively low drop in follow-up costs did not compensate for the higher purchase price of drug-eluting stents, and that doctors would be paying almost $35,000 per improved patient outcome. Cost-effectiveness improved, however, when considering only high-risk patients.

The investigation's conclusions are already guiding stent choice at the University Hospital of Basel, Pfisterer said. The study is also being examined by bodies in the U.K. and the Netherlands that are responsible for setting clinical practice guidelines.

Should device costs change considerably in the next five years, the study can still serve as a working model for cost-effectiveness, Pfisterer said.

"We now have the exact data on how these costs and effects relate to each other. If the costs come down, we just put in the new figures and recalculate it all again," he said.

For more information from the Diagnostic Imaging archives:

Carotid artery stenting takes off despite limits

Long-term data validate thoracic aortic stenting

Quantitative assessment provides valuable tool to crunch data

Drug-eluting stents soothe postop inflammation