9.1 Coronary Sinus Reduction for Refractory Ischemia

These proceedings summarize the educational activity of the 16th Biennial Meeting of the International Andreas Gruentzig Society held January 31-February 3, 2022 in Punta Cana, Dominican Republic

Faculty Disclosures     Vendor Acknowledgments

2022 IAGS Summary Document

Statement of problem or issue

Chronic angina, refractory to medical or interventional therapies, is a common and disabling medical problem affecting more than 100 million people worldwide.¹ It is the most common symptom of myocardial ischemia. Patients with chronic angina may have obstructive or nonobstructive coronary disease that is unsuitable for revascularization. Furthermore, a substantial number of patients (more than 30%) continue to suffer from angina following a “successful” revascularization. In patients with angina and no significant obstructive coronary disease, more than 40% have microvascular disease present.

Coronary sinus reduction to treat angina was pioneered by a cardiac surgeon, Dr Claude Beck.² Between 1948 and 1964, Beck treated more than 1000 patients surgically with a partial ligation of the coronary sinus, achieving very good results. The physiological basis for this is illustrated in Figure 1.³ Obstructive coronary artery disease, either epicardial or microvascular, alters the epicardial-to-endocardial flow ratio (Epi/Endo) such that ischemia can exist. Partial obstruction of the coronary sinus raises venous pressure in the intramyocardial veins, restoring the Epi/Endo ratio back to a more normal value.

Gaps in knowledge

While the surgical approach to coronary sinus reduction is no longer undertaken, a number of percutaneous devices have been developed to achieve this goal. The intermittent occlusion procedure PICSO (pressure-controlled intermittent coronary sinus occlusion) was tested and found to be helpful in reducing infarct size and ischemia both in animal models and in STEMI patients.^4-6 More recently, a novel stent device placed into the coronary sinus via a balloon catheter has been successfully used. The efficacy of this approach was tested in preliminary studies, and a larger-scale evaluation is currently underway. It is important to point out that we do not know for certain what patient groups might benefit.

Possible solutions and future directions

The transcatheter coronary sinus reducer has been tested in small clinical studies and a small randomized trial of 104 patients.⁷ A much larger randomized trial, COSIRA II (NCT05102019), involving several hundred patients, is now underway. Enrollment is expected to be completed in 2024, with results available in 2028. Moreover, the effectiveness of the coronary sinus reducer in improving coronary microvascular function and angina is being investigated in an early phase study (NCT045231682).

References

1. GBD 2015 Mortality and Causes of Death Collaborators. Global, regional, and national life expectancy, all-cause mortality, and cause-specific mortality for 249 causes of death, 1980-2015: a systematic analysis for the Global Burden of Disease Study 2015. Lancet. 2016;388(10053):1459-1544. Erratum 2017;389(10064):e1 doi:10.1016/S0140-6736(16)31012-1

2. Beck CS, Leighninger DS. Scientific basis for the surgical treatment of coronary artery disease. J Am Med Assoc. 1955;159(13):1264-1271. doi:10.1001/jama.1955.02960300008003

3. Ielasi A, Todaro MC, Grigis G, Tespili M. Coronary sinus reducer system: A new therapeutic option in refractory angina patients unsuitable for revascularization. Int J Cardiol. 2016;209:122-130. Epub 2016 Feb 3. doi:10.1016/j.ijcard.2016.02.018

4. Mohl W, Gangl C, Jusić A, Aschacher T, De Jonge M, Rattay F. PICSO: from myocardial salvage to tissue regeneration. Cardiovasc Revasc Med. 2015;16(1):36-46. doi:10.1016/j.carrev.2014.12.004

5. van de Hoef TP, Nijveldt R, van der Ent M, et al. Pressure-controlled intermittent coronary sinus occlusion (PICSO) in acute ST-segment elevation myocardial infarction: results of the Prepare RAMSES safety and feasibility study. EuroIntervention. 2015;11(1):37-44. doi:10.4244/EIJY15M03_10

6. De Maria GL, Alkhalil M, Borlotti A, et al. Index of microcirculatory resistance-guided therapy with pressure-controlled intermittent coronary sinus occlusion improves coronary microvascular function and reduces infarct size in patients with ST-elevation myocardial infarction: the Oxford Acute Myocardial Infarctio—Pressure-controlled Intermittent Coronary Sinus Occlusion study (OxAMI-PICSO study). EuroIntervention. 2018;14(3):e352-e359. doi:10.4244/EIJ-D-18-00378

7. Verheye S, Jolicœur EM, Behan MW, et al. Efficacy of a device to narrow the coronary sinus in refractory angina. N Engl J Med. 2015;372(6):519-527. doi:10.1056/NEJMoa1402556