666 OBSTRUCTIVE CORONARY ARTERY DISEASE: WHEN CORONARY ANGIOGRAPHY IS NOT ENOUGH.


 
 
 Coronary angiography is the gold standard approach to assess coronary artery disease, especially in acute settings. Additional morphological and functional methods such as intravascular ultrasound (IVUS), optical coherence tomography (OCT), and fractional flow reserve or instantaneous wave free ratio (FFR or iFR) are used to confirm hemodynamic relevance of stenoses, to characterise plaque morphology and vessel size and to optimise stent implantation. This abstract presents a clinical case in which intracoronary imaging, in particular OCT, was essential in proper diagnosis and treatment of a patient presenting with acute coronary syndrome (ACS).
 
 
 
 A 43-year-old female patient with no cardiac medical history presented with new onset chest pain occurring at rest from the night before. At admission, a 12-lead ECG showed sinus rhythm with negative T-waves in the precordial leads, hypokinesia of the anterior and apical wall of the left ventricle was found at echocardiography, and high sensitive cardiac troponin was slightly elevated at the first two measurements. The patient was admitted to the Intensive Coronary Unit with the diagnosis of non-ST segment elevation myocardial infarction and underwent coronary angiography within 24 hours of presentation. A slightly inhomogeneous distribution of dye was found at the ostium of left anterior descending artery (LAD). It was interpreted as a possible type 3 spontaneous coronary artery dissection or as the presence of a non obstructive stenoses. No significant findings were observed in the other cardiac vessels. Due to the discrepancy between the clinical presentation and the angiographic findings, additional morphological and functional assessment of LAD was performed. The OCT revealed the presence of an eccentric obstructive plaque on ostial LAD, and the functional study with FFR confirmed the hemodynamic significance of the stenosis. The patient therefore underwent revascularization with drug-eluting stent implantation on left-main/LAD axis; post-angioplasty OCT confirmed the correct stent position. The patient remained hemodynamically stable during the following hospital stay and was discharged on day 7, with a preserved global left ventricular function and persistence of apical wall hypokinesia, slow ECG evolution with regression of negative anterior T-waves and no sign of necrosis was also observed.
 
 
 
 There are several angiographically undetectable lesions that can be identified only by IVUS or OCT. In this case the angiographic findings were of difficult interpretation, coronary angiography alone would have been inconclusive and would have led to the diagnosis of myocardial infarction with non-obstructive coronary arteries. This case highlights the importance of intravascular imaging and functional study to guide revascularization also in the acute settings of an ACS.
