Temporal evolution of the human coronary collateral circulation after myocardial infarction

Abstract

An analysis of the coronary collateral circulation in a consecutive series of 116 postinfarction angiograms from patients with persistent 100% occlusion of their infarct artery is reported. Patients were classified into four groups according to the interval between acute infarction and angiography. Of 42 patients studied within 6 hours of infarction (Group I), 52% had no evidence of any coronary collateral development as compared with only 8% (1 of 16 patients) studied 1 day to 2 weeks after infarction (Group II). Virtually all patients studied beyond 2 weeks after myocardial infarction (14 to 45 days, Group III) and later than 45 days (Group IV) had visible collateral flow. Angiographically "well developed" collateral channels were seen in only 16% of Group I patients compared with 62, 75 and 84% of patients in Groups II to IV, respectively. Of six patients studied twice, on the day of the infarction and 2 weeks later, only one patient had collateral vessels on the day of infarction, whereas all six patients did at follow-up study. Group I patients were studied as part of a randomized acute myocardial infarction reperfusion trial, whereas the other patients were referred for angiography primarily because of post-infarction ischemia. Within the limitations imposed by the patient selection process, it is concluded that well developed coronary collateral vessels are rarely present at the time of infarction. After infarction, they develop rapidly and are generally demonstrable within 2 weeks. It may also be inferred that the preservation of ischemic myocardium by well developed coronary collateral vessels at the time of myocardial infarction may be an uncommon occurrence.

Angiographic Assessment of Collateral Connections in Comparison With Invasively Determined Collateral Function in Chronic Coronary Occlusions

“…25,26 Therefore, we assessed the prediction of collateral adequacy to preserve LV function by this new grading system in a subgroup of patients without a prior MI. Only CC1 and CC2 collaterals were found in these patients, and the regional wall motion was best preserved with grade CC2 collaterals.…”

Intravenous streptokinase for acute myocardial infarction. Effects on global and regional systolic function.

“…Collateral vessels could provide a protective effect in patients failing to reperfuse,22.23 thereby tending to minimize treatment-control differences in ventricular function. However, because we have no data on the prevalence of collaterals in the first few hours of infarction and because collaterals often develop rapidly over the first 2 weeks after myocardial infarction, 24 we cannot be certain of the effect of collaterals in the present study.…”

Coronary Collateral Circulation

“…In experiments with dogs, gradual occlusion of LCx within 2-3 weeks is not associated with myocardial infarction in most of the cases, and, when infarction occurs, it is larger in animals with poor development of collateral vessels.3 Sudden occlusion of LCx in dogs results in myocardial infarction in all animals.34 When a coronary arteriogram is performed in humans during the acute stage of myocardial infarction, collateral circulation is not usually extensive. 20,23,35 When the arteriogram is performed two weeks later, collateral vessels are visible in most of the patients, especially in association with total occlusion of the coronary artery.23.35,36 The degree ofcoronary stenosis prior to infarction may predict the visibility of collaterals, since collateral circulation during acute infarction is more frequent in preinfarction angina than in its absence.37 There are also case reports of patients with acute traumatic coronary occlusion with otherwise healthy coronary arteries, in whom collateral vessels to the occluded artery have developed within days. 2,38 In humans, the functional significance of collateral circulation during acute infarction seems obvious on the basis of several observations in which the presence of collaterals is associated with improved left ventricular ejection fraction, a smaller degree of regional contraction abnormalities, a better cardiac index, and a smaller rise of the serum creatine kinase (CK) MB activity.2n,21,23,24,39…”