Yang ZK, Shen Y, Dai Y, et al. - Researchers investigated individuals with type 2 diabetes mellitus (T2DM) who had a successful percutaneous coronary intervention (PCI) for chronic total occlusion (CTO), to determine the prognostic role of coronary collaterals in these patients following the procedure. They used Rentrop scoring system to grade coronary collateralization among 198 type 2 diabetic patients and 335 non-diabetics experiencing stable angina undergoing PCI for at least one CTO lesion. At 13.5 ± 4.1 months, a lower rate of composite major adverse cardio-cerebral events and repeat revascularization as well as a greater rise in left ventricular ejection fraction was noted in patients with good collaterals vs those with poor collaterals for non-diabetic group. Overall, findings revealed a link of T2DM with decreased coronary collateralization. Among type 2 diabetic patients and non-diabetics, the impacts of the status of coronary collateralization on long-term clinical results as well as left ventricular function seemed to be similar in size following successful recanalization of CTO.