METHODS - We conducted a multicenter, randomized study involving 240 patients with non-ST-segment elevation acute coronary syndromes to compare OCT-guided PCI (use of OCT pre- and post-PCI; OCT-guided group) to fluoroscopy-guided PCI (angiography-guided group). The primary end point was the functional result of PCI assessed by the measure of post PCI fractional flow reserve. Secondary end points included procedural complications and type 4a periprocedural myocardial infarction. Safety was assessed by the rate of acute kidney injury.

RESULTS - OCT use led to a change in procedural strategy in 50% of the patients in the OCT-guided group. The primary end point was improved in the OCT-guided group, with a significantly higher fractional flow reserve value (0.94±0.04 versus 0.92±0.05, P=0.005) compared with the angiography-guided group. There was no significant difference in the rate of type 4a myocardial infarction (33% in the OCT-group versus 40% in the angiography-guided group, P=0.28). The rates of procedural complications (5.8%) and acute kidney injury (1.6%) were identical in each group despite longer procedure time and use of more contrast medium in the OCT-guided group. Post-PCI OCT revealed stent underexpansion in 42% of patients, stent malapposition in 32%, incomplete lesion coverage in 20%, and edge dissection in 37.5%. This led to the more frequent use of poststent overdilation in the OCT-guided group versus the angiography-guided group (43% versus 12.5%, P<0.0001) with lower residual stenosis (7.0±4.3% versus 8.7±6.3%, P=0.01).

CONCLUSIONS - In patients with non-ST-segment elevation acute coronary syndromes, OCT-guided PCI is associated with higher postprocedure fractional flow reserve than PCI guided by angiography alone. OCT did not increase periprocedural complications, type 4a myocardial infarction, or acute kidney injury.

CLINICAL TRIAL REGISTRATION - URL: http://www.clinicaltrials.gov. Unique identifier: NCT01743274.

© 2016 American Heart Association, Inc.