NEW YORK (Reuters Health) - By promoting collateral blood flow, a new stent that reduces the size of the coronary sinus can improve chronic refractory angina pectoris in patients who are not candidates for revascularization procedures, according to a report in the May 1st issue of the Journal of the American College of Cardiology.

Increased coronary sinus pressure can lead to a redistribution of collateral blood flow from nonischemic to ischemic areas, the authors explain. The coronary sinus reducer is designed to narrow the coronary sinus and thereby increase coronary venous pressure.

Dr. Shmuel Banai from Tel Aviv Medical Center, Israel and colleagues used the device to treat 15 patients with reversible myocardial ischemia and severe refractory angina.

All implantation procedures were successful, the authors report, and patients left the hospital after 1 or 2 days with no clinical complications.

Angina score improved significantly 6 months after implantation of the coronary sinus reducer, the results indicate, with most patients reporting improvements in anginal symptoms and quality of life several weeks after implantation (rather than immediately).

For 9 of 11 patients tested, exercise duration and peak heart rate increased at the 6-month stress test (compared with baseline), the researchers note. Average ST-segment depression also decreased significantly.

Eight of 13 patients who underwent dobutamine echocardiography experienced medically significant improvements between baseline and the 6-month evaluation, the report indicates. Similarly, 4 of 10 patients showed significant reductions in myocardial ischemia measured by thallium SPECT perfusion studies.

"The present study has shown that the use of this new technique to establish a narrowing of the coronary sinus is feasible and safe," the investigators conclude. The results "support further evaluation of the Reducer as an alternative treatment for patients with chronic refractory angina who are not candidates for coronary revascularization."