At the ESC Congress 2016 (August 27-31, 2016; Rome, Italy), the European Society of Cardiology's annual meeting, researchers at University Hospital Jean Minjoz (Besançon, France) demonstrated that optical coherence tomography (OCT) imaging can visualize the coronary arteries in patients undergoing percutaneous coronary intervention (PCI) and lead to better outcomes compared to standard angiography-guided PCI.
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In patients with non-sinustachycardia (ST)-segment elevation acute coronary syndromes (NSTE-ACS), OCT provided useful additional information beyond that obtained by angiography alone, and impacted directly on physician decision-making, according to Nicolas Meneveau, MD, Ph.D, the Does Optical Coherence Tomography Optimize Results of Stenting (DOCTORS) study's lead investigator.
OCT, which involves introducing an imaging catheter into the coronary artery to check vessel size, lesion characteristics, and stent positioning, and expansion, led to a change in procedural strategy in half of cases, Meneveau says. However, additional prospective randomized studies with clinical endpoints are required before it can be recommended for standard use, he adds.
The multi-center DOCTORS study included 240 NSTE-ACS patients who were randomized 1:1 to standard fluoroscopy-guided PCI alone (angio group) and with the addition of OCT performed an average of 3.8 times before, during, and after the procedure. Overall, OCT was associated with better functional outcome than PCI guided by fluoroscopy alone, Meneveau says.
The primary endpoint of the study, which was fractional flow reserve (FFR; a measure of blood flow and pressure in the coronary artery before and after the procedure), was significantly better in the OCT group as compared to the angio group (0.94 vs. 0.92, p=0.005). In addition, the number of patients with a post-procedural FFR >0.90 was significantly higher in the OCT group (82.5% vs. 64.2%, p=0.0001).
Compared to angiography, OCT allowed clinicians to see significantly more thrombi (69% vs. 47%, p=0.0004) and calcifications (45.8% vs. 9%, p<0.0001) before stent implantation. This resulted in more frequent antiplatelet use in the OCT group (53.3% vs. 35.8%). OCT was also significantly more likely to reveal stent underexpansion (42% vs. 10.8%), incomplete lesion coverage (20% vs. 17%), and edge dissection (37.5% vs. 4%) compared to angiography. Stent malapposition, which is not visible under fluoroscopy alone, was observed in 32% of patients undergoing OCT.
These observations led to the more frequent use of post-stent overinflation in the OCT group (43% vs. 12.5%, p<0.0001) and a lower percentage of residual stenosis (7.0% vs. 8.7%, p=0.01).
The addition of OCT increased procedure time as well as patients' exposure to fluoroscopy and contrast medium, but this did not increase complications such as peri-procedural myocardial infarction or impaired kidney function, Meneveau says. "The improvement in functional outcomes could translate into a clinical benefit in the longer term," he adds.
Details of the work also appear in the journal Circulation; for more information, please visit http://circ.ahajournals.org/content/early/2016/08/28/circulationaha.116.024393.
