October 14, 2020
Combined FFR and OCT Imaging Studied to Identify High-Risk Lesions in Patients With Diabetes
October 14, 2020—The COMBINE (OCT-FFR) study found that the use of fractional flow reserve (FFR) combined with optical coherence tomography (OCT) imaging can help improve the accuracy of high-risk lesion identification in patients with diabetes.
“In patients with diabetes, COMBINE (OCT-FFR) showed that the presence of a high-risk plaque (thin-cap fibroatheroma [TCFA]) is a strong predictor of future major adverse cardiovascular events (MACE), despite lack of ischemia,” commented principal investigator Elvin Kedhi, MD, Professor of Cardiology, working in ULB (Liberal University Brussel) Hôpital Erasme and Silesian Medical University, Katowice, Poland.
Professor Kehdi continued, “Additionally, patients with high-risk plaques (TCFAs) have a significant increase in target-lesion related MACE and myocardial infarction (MI) compared to patients without TCFA at 18 months. These findings indicate that combining FFR and OCT can improve the accuracy of high-risk lesion and patient identification and should be adopted in practice.”
The findings were reported at TCT Connect, the 32nd annual Transcatheter Cardiovascular Therapeutics scientific symposium of the Cardiovascular Research Foundation (CRF) held online October 14¬–18, 2020.
As explained in the TCT press release, FFR is widely used to guide the revascularization strategy in the catheterization lab. The FAME I and FAME II trials showed that stable ischemic heart disease lesions with FFR > 0.8 can be safely treated medically, while percutaneous coronary intervention (PCI) of lesions with FFR < 0.8 may benefit from revascularization.
However, recent evidence has shown that in some patient subgroups, such as diabetes mellitus (DM) and/or acute coronary syndrome (ACS), lesions with FFR > 0.8 can have worse outcomes than in patients without DM or ACS, most likely caused by plaque instability or rapid progression of atherosclerotic plaque. Previous studies have shown that lipid-rich plaques with a TCFA have unfavorable clinical outcomes compared to non-TCFA lesions, particularly in DM patients. OCT can accurately identify lipid-rich and TCFA lesions.
Whether OCT can identify lesions with future unfavorable clinical events despite lack of ischemia has not been studied previously.
According to TCT announcement, the COMBINE (OCT-FFR) is a prospective international, natural history study. Patients with DM and with stable or acute coronary syndromes who had one or more nonculprit target lesions, with a 40-80% diameter stenosis, underwent FFR assessment. FFR-negative patients underwent OCT assessment and were further medically treated.
Depending on the presence or absence of TCFA, patients were divided in two groups: TCFA negative (group A) and TCFA positive (group B). Patients with target lesions with FFR < 0.8 were revascularized (group C).
The primary endpoint was the incidence of target lesion related MACE defined as cardiac death, target vessel MI, clinically driven target lesion revascularization (TLR), or hospitalization due to unstable or progressive angina at 18 months in the medically treated patients with FFR > 0.8 and TCFA patients (group B) compared with medically treated patients with FFR > 0.8 and no TCFA (group A).
The secondary endpoint was the incidence of MACE between patients with FFR > 0.8 and TCFA (group B) versus revascularized lesions that had FFR < 0.8 (group C).
The primary endpoint occurred in 13.3% of group B compared with 3.1% of group A (hazard ratio [HR], 4.7; 95% CI, 2.0-10.9; P = .0004), suggesting that the presence of TCFA even in the absence of an abnormal FFR was predictive of future events. The rate of adverse events was even higher than the rate of events among revascularized lesions with abnormal FFR at baseline (group C; HR, 1.25; 95% CI, 0.28-5.59; P = .77).