Modulation of coronary sinus pressure decreases microvascular resistances in the right coronary artery and improves symptoms of microvascular angina

Le résumé fourni par la source

The coronary venous circulation is attributed a marginal role in regulating myocardial perfusion. Evidence suggests that elevation of coronary sinus (CS) pressure can reduce coronary microvascular resistances,1 possibly through the recruitment of previously dormant capillary networks in the territory of the left anterior descending coronary. Microvascular dysfunction may, however, selectively involve the right coronary (RCA) bed, which is not directly tributary of the CS. Microvascular resistances (IMR) and flow reserve (CFR) were assessed in a 64-year-old man with normal ventricular function, Canadian Cardiovascular Society (CCS) angina class 3, no epicardial stenosis, and evidence of inducible ischaemia of the posterolateral wall. Severe microvascular dysfunction with a ‘high resistances’ endotype, most pronounced in the RCA territory, was shown (left panels, normal values: IMR < 25, CFR > 2.5). Measurements were then repeated during temporary CS occlusion with a Swan-Ganz balloon (right panel, *). The resulting increase in CS pressure was associated with a 40% decrease in IMR and a 75% increase in CFR measured in the RCA (right panels, * marks the pressure wire X, Abbott Vascular). It was therefore decided to implant a CS reducer. Four weeks after implantation, the patient reported improved symptoms from CCS class 3 to class 2.

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