“…First, percutaneous CTO recanalisation is often considered to be technically difficult, resource-demanding and time-demanding, with a complication rate exceeding that of a non-CTO PCI. However, recent advances in the interventional technique, both antegrade and retrograde, including the hybrid algorithm, have resulted in >90% procedural success rates, while being associated with a low occurrence of major complications, such as cardiac tamponade, myocardial infarction and death (all well below 1%) 1. Second, the evidence base regarding clinical benefits of CTO PCI over medical therapy has largely been confined to observational data, stemming mainly from retrospective comparisons of clinical outcomes in patients with successful versus failed CTO PCI,1 whereas randomised studies evaluating the effects of PCI versus medical therapy for CTO have been scarce.…”