Contradictory Effect of Coronary Collateral Circulation on Regional Myocardial Perfusion That Assessed by Quantitative Myocardial Perfusion Scintigraphy

Abstract

Background: Previous studies showed conflicting results about the contribution of coronary collateral circulation (CCC) to myocardial perfusion and function. The aim of this study was to investigate these contradictory problems by gated myocardial perfusion scintigraphy (gated MPS) for the first time. Methods:The current cohort was retrospectively selected among patients who underwent gated MPS and coronary angiography within 2 months. Two different groups including 96 patients were assessed by gated MPS to detect the understanding of the miscellaneous effect of CCC on myocardial perfusion. Group 1 consisted of those who had collateral arteries that were not-well-developed (Rentrop grade 0 -1) (n = 58), while group 2 consisted of those who had collateral arteries that were well-developed (Rentrop grade 2 -3) (n = 38).Results: There was no statistically significant difference between groups 1 and 2 in terms of perfusion and functional parameters obtained from gated MPS. Furthermore, no statistically significant difference was found in the phase analysis parameters which is a novel technique to evaluate left ventricular synchronization. On the other hand the left ventricular mass index values were high and quite close to the statistically significant value (P = 0.059) in group 2. Conclusions:The current results that obtained by using the gated MPS technique for the first time in the evaluation of CCC showed that the well-developed collateral circulation has a positive effect on myocardial perfusion and function, but this effect was not statistically significant. Results need to be supported by large scale of patients' size.

Impact of coronary collateralization on major adverse cardiovascular and cerebrovascular events after successful recanalization of chronic total occlusion

“…This impaired collateralization may result from genetic predisposition, microvascular dysfunction, or inadequate release of pro-angiogenic factors ( 25 , 26 ). Inadequate collateral support resulted in ongoing myocardial ischemia, impaired myocardial function, and increased susceptibility to adverse events ( 27 , 28 ). Furthermore, consistent with our results, stent thrombosis was more prevalent in poor CCC, as collateral flow has been shown to protect against thrombus formation and facilitate myocardial reperfusion ( 29 ).…”

Early recruitable coronary collaterals preserve miocardial viability in late presentation infarctions

“…The influence of CCC on left ventricular function in MIs remains controversial, the majority of previous studies have reported a higher global LVEF at hospital discharge but some others have not [11,14,16,27].…”

“…In patients presenting MI, some previous reports demonstrate that a high degree of collateralization to the IRA is related to a reduced infarct burden and myocardial savage, improving prognosis [8][9][10][11][12][13]. Nevertheless, other studies have failed to demonstrate any benefits in terms of myocardial viability from CCC in MI patients [14,16,31]. As mentioned above, in the primary angioplasty era, the role of CCC in these studies may have been influenced by the effect of early coronary reperfusion, which is a recognizable factor to predict myocardial viability and prognosis in these patients.…”

“…Conversely, the extent of myocardial scar is associated with left ventricular remodeling and increased risk of sudden death [6]. Previous studies have shown conflicting results regarding the contribution of early coronary collateral circulation (CCC) to myocardial viability and function in the setting of MI and in other clinical scenarios [7][8][9][10][11][12][13][14]. But, of note, in the primary angioplasty era, the role of CCC in the setting of MI may have been influenced by the effect of early coronary reperfusion.…”