Standardising the complexity of contemporary PCI

The field of percutaneous coronary intervention (PCI) has evolved substantially over the last 3 decades1. Initially performed mostly among patients with single, focal coronary lesions, PCI is now being applied across the entire spectrum of coronary artery disease complexity1. Technological innovations and iterations in drug-eluting stent platforms, intravascular imaging, plaque modification, antithrombotic therapies, and mechanical circulatory support have made this possible2. Currently, it is estimated that approximately 30% of patients undergo complex PCI procedures. However, a universally accepted definition of “complex PCI” does not exist. About 10 years ago, at a time when there was intense debate on the optimal duration of dual antiplatelet therapy post-PCI, we first proposed an intuitive and easy-to-use definition of “complex PCI” to try to identify patients at higher risk of ischaemic events who may derive a greater benefit from prolonged or more intense antithrombotic therapies3. Since then, the criteria for complex PCI have been evaluated in many subsequent observational studies and subgroup analyses of randomised controlled trials and have been endorsed by the European Society of Cardiology (ESC) and the...