Changes in absolute coronary blood flow and myocardial resistance after percutaneous coronary intervention

BACKGROUND: Treating a coronary stenosis by percutaneous coronary intervention (PCI) aims to relieve myocardial ischaemia by improving coronary blood flow. The evolution of coronary flow and resistance post-PCI is not fully understood. AIMS: ). METHODS: In a two-centre cohort including 52 patients, pre- and post-PCI physiological assessments were performed using continuous thermodilution, via a combination of a pressure-temperature sensor wire and a dedicated infusion microcatheter. RESULTS: and predicted the improvement of hyperaemic Q. CONCLUSIONS: PCI significantly reduces epicardial resistance, leading to a pronounced increase in hyperaemic flow, which can be predicted by FFR. Resting Q remained unchanged because of compensatory increases in microvascular resistance, providing direct evidence of coronary flow autoregulation in humans. The MRR was unaffected by PCI, confirming its specificity as an index of microvascular function.