Coronary Sinus Reducer for Treatment of Refractory Angina - COSIRA


The goal of the trial was to evaluate treatment with a coronary sinus stent, designed to reduce coronary flow and thus elevate coronary sinus pressure, among patients with refractory angina.


The hypothesis is that increased coronary sinus pressure can lead to redistribution of collateral flow into ischemic territories and reduce angina burden.

Study Design

  • Randomized
  • Blinded
  • Parallel

Patient Populations:

  • Patients with refractory angina (CCS class III or IV) on optimal medical therapy with evidence of myocardial ischemia (by dobutamine stress echo) and no suitable targets for revascularization

    Number of screened applicants: 166
    Number of enrollees: 104
    Duration of follow-up: 6 months
    Mean patient age: 66 years
    Percentage female: 23%
    Left ventricular ejection fraction >25%


  • Recent revascularization
  • Recent acute coronary syndrome
  • Prior pacemaker or defibrillator
  • Elevated right atrial pressure (≥15 mm Hg)
  • Tortuous, aberrant, or large coronary sinus

Primary Endpoints:

  • Primary efficacy endpoint: improvement in ≥2 CCS grades from baseline to 6 months
  • Primary safety endpoint: successful delivery and deployment of the coronary sinus reducer to the intended site

Drug/Procedures Used:

Patients with refractory angina were randomized to the coronary sinus stent (n = 52) versus sham (n = 52).

Principal Findings:

Overall, 104 patients were randomized. The mean age was 66 years, 23% were women, 58% had a previous myocardial infarction, 48% had diabetes, and 79% had hypertension.

The primary outcome of improvement in angina ≥2 Canadian Cardiovascular Society (CCS) grades occurred in 35% of the coronary sinus stent group versus 15% of the sham group (p = 0.024). At least one CCS grade improvement occurred in 71% of the coronary sinus stent group versus 42% of the sham group (p = 0.003). At baseline, the mean CCS was 3.2 in the stent group and 2.1 at follow-up (p = 0.001). At baseline, the mean CCS was 3.1 in the sham group and 2.7 at follow-up (p = 0.001).

The coronary sinus stent was associated with an improvement in quality of life (hazard ratio [HR] 2.7, p = 0.03), angina stability (HR 2.5, p = 0.1), and angina frequency (HR 1.5, p = 0.4). The technical success rate was 96%, and procedural success was 100%.

One patient had a non-ST-elevation myocardial infarction on the day after implant due to a circumflex lesion. This was adjudicated as possibly related to the device.


Among patients with refractory angina with coronary lesions unable to be revascularized, the implantation of a coronary sinus stent was feasible. Patients in both groups (device and sham) experienced an improvement in angina class; however, more patients in the stent group reached the primary outcome (angina improvement ≥2 CCS grades). Magnitude of benefit for treatment effects is often exaggerated in small initial studies. Larger studies are warranted.


Presented by Dr. Stefan Verheye at the American College of Cardiology Scientific Session, Washington, DC, March 29, 2014.

Clinical Topics: Invasive Cardiovascular Angiography and Intervention, Prevention, Hypertension

Keywords: Myocardial Infarction, Dobutamine, Coronary Sinus, Quality of Life, Cost of Illness, Hypertension, Diabetes Mellitus, Stents, ACC Annual Scientific Session

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