What are the results of using a new experimental stent
On February 5, 2015, the New England Journal of Medicine published the results of a phase 2 randomized clinical trial involving 104 patients with severe angina refractory to medical therapy.
Implantation in the coronary sinus of the new experimental stent, named Reducer (manufacturer Neovasc), led to a significant reduction in the manifestation of symptoms and an improvement in the quality of life after 6 months compared to the placebo procedure.
Unlike conventional stents, which widen the lumen of arteries, this new balloon-inflatable hourglass-shaped cellular device aims to create an obstruction and thus increase the pressure in the coronary sinus, leading to an increase in blood flow to the ischemic region of the myocardium.
The study, named “Reducer Coronary Sinus Reducer for Treatment of Refractory Angina” (COSIRA), showed that this method is the safest and relatively simple method of treating patients with stable to drug therapy for angina pectoris and a very low quality of life.
The COSIRA study, which lasted from 2010 to 2013, involved 11 centers located in Belgium, Canada, the Netherlands, Denmark and Sweden. A total of 104 patients aged 18 and over took part.
Criteria for inclusion in the study were the presence of angina pectoris 3rd or 4th functional class according to the classification of the Canadian Cardiovascular Society (CCS), and the symptoms should not be able to be controlled with the help of beta-blockers. calcium channel blockers, nicorandil, ivabrandin and short- and long-acting nitrates.
All patients also had confirmed reversible myocardial ischemia and a left ventricular ejection fraction below 25%. Performing myocardial revascularization in them was impossible.
The average age of the participants was 67.8 years, 81% were men, 84% had 3 functional class according to CCS. About ¾ of the patients had previously undergone aorto-coronary bypass surgery or percutaneous coronary interventions.
Patients were randomized into groups with implanted devices /technically they were introduced into the coronary sinus through the right jugular vein/ and with a placebo procedure. At the beginning and 6 months after the intervention, a study was carried out using stress echocardiography with dobutamine on the ability of the myocardium to contract.
At 6 months, 18 of 52 patients in the active treatment group and 8 of 52 patients in the control group experienced an improvement of at least 2 CCS functional classes, which was the primary efficacy endpoint /35% against 15% P=0.02/.
The mean value of the CCS functional class decreased in the treated group from 3.2 to 2.1, and in the control group – from 3.1 to 2.6 / P=0.001 /. However, an improvement of one CCS functional class was found in 71% of patients in the active treatment group and in 42% after the placebo procedure / P=0.003 /.
Quality of life was determined using the Seattle Angina Questionnaire/ improved by 17.6 points in the treated group and by 7.7 points in the control group / P=0.048/.
A total of 76 adverse events occurred in the group of patients with an implanted device, and 93 in those in which the placebo procedure was performed.
In the control group, 3 myocardial infarctions occurred and 1 patient died – from multiple organ failure, in the actively treated group there were no registered deaths, but one periprocedural myocardial infarction occurred.
