The Human Myocardial Stain as Mitigated by Coronary Collaterals

Abstract

If the human coronary artery tree were an end-arterial system, ie, one without interarterial anastomoses, as stated in 1881 by Cohnheim et al on the basis of canine studies,1 permanent total upstream occlusion of an epicardial branch would invariably result in the necrosis of the downstream myocardium. So far, data from less historical works have, however, indicated an absence of myocardial infarction in 50% of patients with chronic coronary artery occlusion.2 One of the concluding remarks of the study by Choi and coworkers3 published in the present issue of Circulation is that “most patients with chronic coronary artery occlusions show evidence of prior myocardial infarction.” Are we on the way back to Cohnheim’s paradigm? Maybe not, because Choi et al3 reassure the reader that it is the presence of coronary collaterals that mitigates the transmural extent of myocardial scar and regional wall-motion abnormalities (Figure 1). Figure 1. Chronic total occlusion of the proximal left anterior descending coronary artery (LAD; arrow ) with a normal left ventricular angiogram ( upper panels ). Contrast injection into the right coronary artery (RCA) of the same patient shows complete retrograde filling of the LAD via a branch collateral artery ( white arrow ) up to the proximal occlusion site ( lower panel ). Article see p 703 Moliere’s “imaginary invalid” ( Le Malade Imaginaire , 1673, a 3-act comedie-ballet) may challenge psychiatrists, but the gradual extinction of the “imaginary sane” by new “evidence,” that is, increasingly sensitive diagnostic tools, could pose similar problems. “Most” in the above-quoted sentence is equal to not quite the 100% as ordered by Cohnheim but rather to 86%, which could be reasonably translated to “most” only if the study accounted for all patients with chronic coronary artery occlusion. However, the “imaginary sane” with stained myocardium not admitted to a hospital because of well-being …