Invasive coronary angiography, FFR and QCA

Invasive coronary angiography and FFR were performed as per standard practice via the femoral or radial approach. An FFR value ≤0.80 was taken to define functionally significant stenoses. The pressure wire (Pressure wire Certus 6, St Jude Medical, USA) was calibrated and electronically equalised with the aortic pressure before being placed in the distal third of the coronary artery being interrogated. Intracoronary glyceryl trinitrate (100 mcg) was injected to minimise vasospasm. Intravenous adenosine was administered (140 mcg/kg/min) through an intravenous line in the antecubital fossa. At steady-state hyperaemia, FFR was recorded on a RadiAnalyzer Xpress (St Jude Medical Systems, USA), calculated by dividing the coronary pressure measured with the sensor placed distal to the stenosis (Pd) by the aortic pressure measured through the guide catheter (Pa). Quantitative coronary angiographic analysis was performed to derive minimal luminal diameter (MLD) and lesion length.