The objective of this study is to compare the clinical outcome of Non-ST-elevation myocardial infarction (NSTEMI) and ST-elevation myocardial infarction (STEMI) patients with non-obstructive, non-culprit coronary lesions and either presence or absence of vulnerable plaque characteristics as assessed by optical coherence tomography (OCT).

Despite major advances in the treatment of acute coronary syndromes a large proportion of patients is still at risk for new coronary events after experiencing an acute coronary syndrome (ACS). Detection of residual vulnerable plaques after ACS using OCT potentially identifies patients at high risk for new coronary events. However, no prospectively collected data on the prognostic power of OCT for plaque rupture are available at this moment. To design trials aimed to reduce events in patients with vulnerable plaques it is required to collect such prospective data on the relation between OCT derived characteristics of vulnerability and clinical outcome.

Inclusion Criteria:

• Informed consent must be obtained.
• Patients with STEMI or NSTEMI and residual, non-culprit CAD, with the possibility of plaque vulnerability.
• Residual plaque(s) is(are) non-obstructive (FFR≥0.80).

Exclusion Criteria:

• Refusal or inability to provide informed consent.
• < 18 years of age
• Hemodynamic instability, respiratory failure, Kilip class ≥ 3.
• Previous Coronary Artery Bypass Grafting (CABG).
• Indication for revascularization by CABG.
• Anatomy or lesions unsuitable for OCT catheter crossing or imaging (aorta-ostial lesions, small diameter segment, severe calcifications, lesion is too distal for OCT catheter)
• Pregnancy.
• Estimated life expectancy < 3 year