Microvascular dysfunction is an independent predictor of poor prognosis. Such response in the culprit vessel is common even after successful revascularization. This study investigated whether the microvascular dysfunction differed between culprit and non-culprit vessels in patients with acute coronary syndrome (ACS) who underwent percutaneous coronary intervention (PCI).

The prospective study included 115 patients with ACS. In this study, after successful PCI, culprit and non-culprit intracoronary hemodynamic measurements were performed and repeated at 6-month follow-up. 13N-ammonia positron emission tomography (PET) was performed at 6-month follow-up visit to determine absolute myocardial blood flow (MBF). The resistance values of each vessel were calculated using the coronary pressure data and the MBF values obtained from 13N-ammonia PET data. Such physiological measures were compared between culprit and non-culprit vessels in baseline and 6-month follow-up.

Inclusion Criteria:

• Individuals were eligible for inclusion if they underwent PCI for ACS, if the target lesion was found in the proximal or middle segments of a major epicardial coronary artery, and if the lesion was successfully treated with a coronary stent.

Exclusion Criteria:

• a previous infarction other than in the vessel of interest or a history of coronary artery bypass surgery, cardiogenic shock requiring inotropic support, chronic kidney disease requiring renal replacement therapy, hypertrophic cardiomyopathy, collateral flow to the target vessel greater than angiographic grade 1, or statin or ticagrelor use within 1 year.

Patients with acute coronary syndrome