Coronary Sinus Reducer Implantation Improves Chronic Refractory Angina

Hamid Qazi, M.D.
By Hamid Qazi, M.D. on

A recent study published in the Journal of American College of Cardiology found that implantation of the coronary sinus Reducer is safe and is associated with a reduction of anginal symptoms and improvement of quality of life in patients with refractory angina who were not candidates for further revascularization.

The Reducer creates a controlled narrowing of the coronary sinus (CS) lumen which leads to an increase in coronary venous pressure, capillary and arteriolar dilatation, lower resistance to flow, and restoration of the normal endocardial/epicardial blood flow ratio, which is impaired in the ischemic myocardium.

Giannini et al. report that this study includes the largest number of patients treated with coronary sinus Reducer in a single-center, real-world setting. In a real-world group of patients with refractory angina without a further coronary revascularization option, coronary sinus (CS) Reducer implantation was feasible and safe. Additionally, no periprocedural or midterm device-related complications were observed. The clinical effectiveness of this therapy was documented by the reduction of disabling angina symptoms, improvement in quality of life and exercise tolerance, and reduction in the requirement of antianginal drug treatment.

 “Implantation of the coronary sinus Reducer appeared safe and was associated with reduction in anginal symptoms and improvement in quality of life in patients with refractory angina.” – Giannini et al

The study was representative of patients between March 2015 and August 2016 which included 76 patients with severe refractory angina. Following clinical evaluation, 50 patients proceeded to Reducer implantation. Mean Canadian Cardiovascular Society (CCS) angina class at baseline was 2.98+0.52. All patients reported a high anginal burden associated with impaired quality of life, as highlighted by low scores on the Seattle Angina Questionnaire (SAQ), poor exercise tolerance with a mean distance walked of 287±139m, and a median grade of 4.5 (3-5) on the Borg dyspnea scale after exercise. All patients had objective noninvasive evidence of myocardial ischemia in the left coronary artery vascular territory, as documented by myocardial single-photon emission computed tomography, dobutamine stress echocardiography, or perfusion cardiac magnetic resonance imaging. Not unexpectedly, there was a high prevalence of previous myocardial infarction among the study population (66%).

A total of 40 patients (80%) improved by at least 1 CCS class with regard to symptoms following Reducer implantation: 20 patients (40%) demonstrated a 1 CCS class reduction, 16 patients (32%) reported a 2 CCS class reduction, and 4 patients (8%) reported a 3 CCS class reduction. A significant reduction in mean CCS anginal class was seen at 4-month follow-up with respect to baseline: 1.67 vs. 2.98. Of note, a significant reduction in mean New York Heart Association functional class to 1.35±0.60 vs. 1.69±0.68 was also observed. In all patients, 12-month follow up was available. Overall, the significant benefit with regard to angina symptoms was maintained in terms of mean CCS class with respect to baseline: 1.72±0.83 vs. 2.98±0.53. Of note, no significant change in CCS class was observed between 4-month and 1-year follow-up: 1.64±0.82 vs. 1.72±0.83 (p=0.351). The benefit achieved with regard to mean New York Heart Association functional class at 4-month follow-up was maintained at 1 year: 1.23±0.63 vs. 1.68±0.70 (p<0.001).

 The author noted the following important limitations associated with this study: The first limitation was the absence of a control group and the small number of patients enrolled. Secondly, the authors also reported the absence of an objective measurement of myocardial ischemia reduction following Reducer implantation as a potential limitation.

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