The aim of this study was to understand the impact of optical coherence tomography (OCT)-detected thin-cap fibroatheroma (TCFA) on clinical outcomes of diabetes mellitus (DM) patients with fractional flow reserve (FFR)-negative lesions. COMBINE OCT-FFR study was a prospective, double-blind, international, natural history study. After FFR assessment, and revascularization of FFR-positive lesions, patients with ≥1 FFR-negative lesions (target lesions) were classified in two groups based on the presence or absence of ≥1 TCFA lesion. The primary endpoint compared FFR-negative TCFA-positive patients with FFR-negative TCFA-negative patients for a composite of cardiac mortality, target vessel myocardial infarction, clinically driven target lesion revascularization or unstable angina requiring hospitalization at 18 months. Among 550 patients enrolled, 390 (81%) patients had ≥1 FFR-negative lesions. Among FFR-negative patients, 98 (25%) were TCFA positive and 292 (75%) were TCFA negative. The incidence of the primary endpoint was 13.3% and 3.1% in TCFA-positive vs. TCFA-negative groups, respectively (hazard ratio 4.65; 95% confidence interval, 1.99–10.89; P < 0.001). The Cox regression multivariable analysis identified TCFA as the strongest predictor of major adverse clinical events (MACE) (hazard ratio 5.12; 95% confidence interval 2.12–12.34; P < 0.001). Among DM patients with ≥1 FFR-negative lesions, TCFA-positive patients represented 25% of this population and were associated with a five-fold higher rate of MACE despite the absence of ischaemia. This discrepancy between the impact of vulnerable plaque and ischaemia on future adverse events may represent a paradigm shift for coronary artery disease risk stratification in DM patients. Study design and main results.

Background: Autopsy studies have established that thin-cap fibroatheromas (TCFAs) are the most frequent cause of fatal coronary events. In living patients, optical coherence tomography (OCT) has sufficient resolution to accurately differentiate TCFA from thick-cap fibroatheroma (ThCFA) and not lipid rich plaque (non-LRP). However, the impact of OCT-detected plaque phenotype of nonischemic lesions on future adverse events remains unknown. Therefore, we studied the natural history of OCT-detected TCFA, ThCFA, and non-LRP in patients enrolled in the prospective multicenter COMBINE FFR-OCT trial (Combined Optical Coherence Tomography Morphologic and Fractional Flow Reserve Hemodynamic Assessment of Non-Culprit Lesions to Better Predict Adverse Event Outcomes in Diabetes Mellitus Patients). Methods: In the COMBINE FFR-OCT trial, patients with diabetes and ≥1 lesion with a fractional flow reserve >0.80 underwent OCT evaluation and were clinically followed for 18 months. A composite primary end point of cardiac death, target vessel-related myocardial infarction, target-lesion revascularization, and hospitalization for unstable angina was evaluated in relation to OCT-based plaque morphology. Results: A total of 390 patients (age 67.5±9 years; 63% male) with ≥1 nonischemic lesions underwent OCT evaluation: 284 (73%) had ≥1 LRP and 106 (27%) non-LRP lesions. Among LRP patients, 98 (34.5%) had ≥1 TCFA. The primary end point occurred in 7% of LRP patients compared with 1.9% of non-LRP patients (7.0% versus 1.9%; hazard ratio [HR], 3.9 [95% CI, 0.9–16.5]; P =0.068; log rank- P =0.049). However, within LRP patients, TCFA patients had a much higher risk for primary end point compared with ThCFA (13.3% versus 3.8%; HR, 3.8 [95% CI, 1.5–9.5]; P <0.01), and to non-LRP patients (13.3% versus 1.9%; HR, 7.7 [95% CI, 1.7–33.9]; P <0.01), whereas ThCFA patients had risk similar to non-LRP patients (3.8% versus 1.9%; HR, 2.0 [95% CI, 0.42–9.7]; P =0.38). Multivariable analyses identified TCFA as the strongest independent predictor of primary end point (HR, 6.79 [95% CI, 1.50–30.72]; P =0.013). Conclusions: Among diabetes patients with fractional flow reserve-negative lesions, patients carrying TCFA lesions represent only one-third of LRP patients and are associated with a high risk of future events while patients carrying LRP-ThCFA and non-LRP lesions portend benign outcomes. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02989740.

BACKGROUND: Despite fractional flow reserve (FFR)–guided deferral of revascularization, recurrent events in patients with diabetes or after myocardial infarction remain common. This study aimed to assess the association between FFR-negative but high-risk nonculprit lesions and clinical outcomes. METHODS: This is a patient-level pooled analysis of the prospective natural-history COMBINE (OCT-FFR) study (Optical Coherence Tomography Morphologic and Fractional Flow Reserve Assessment in Diabetes Mellitus Patients) and PECTUS-obs study (Identification of Risk Factors for Acute Coronary Events by OCT After STEMI and NSTEMI Patients With Residual Non- Flow Limiting Lesions). Optical coherence tomography was performed on all FFR-negative (FFR >0.80) native nonculprit lesions. Patients or lesions with a high-risk plaque were compared with those without a high-risk plaque. A high-risk plaque was defined in the presence of at least 2 prespecified criteria: (1) lipid arc ≥90 ^o , (2) minimum fibrous cap thickness <65 µm, and (3) presence of either plaque rupture or thrombus. The primary end points were native major adverse cardiovascular events (composite of all-cause mortality, nonfatal myocardial infarction, or unplanned revascularization excluding stent-failure–related events and nonattributable events) and target lesion failure (composite of cardiac death, target vessel myocardial infarction, or target lesion revascularization). RESULTS: Among 810 patients, 450 (55.6%) had a history of diabetes and 482 (59.5%) presented with myocardial infarction. At least 1 high-risk plaque was identified in 271 (33.5%) patients and 287 (30.6%) lesions. Over a median follow-up of 761 (interquartile range, 731–1175) days, the presence of a high-risk plaque was associated with patient-level native major adverse cardiovascular events (hazard ratio, 2.127 [95% CI, 1.451–3.120]; P <0.001) and lesion-level target lesion failure (hazard ratio, 2.623 [95% CI, 1.559–4.414]; P <0.001). The risk of adverse outcomes increased with the copresence of multiple high-risk features. CONCLUSIONS: FFR-negative but high-risk nonculprit lesions are associated with adverse patient- and lesion-level clinical outcomes. These findings emphasize the additional value of intracoronary imaging in patients with FFR-negative nonculprit lesions. REGISTRATION: URL: https://clinicaltrials.gov ; Unique identifier: NCT02989740; Unique identifier: NCT03857971.

Aims: To study if any qualitative or quantitative optical coherence tomography (OCT) variables in combination with thin cap fibroatheroma (TCFA) patients could improve the identification of lesions at risk for future major adverse cardiac events (MACEs). Methods and results: From the combined optical coherence tomography morphologic and fractional flow reserve hemodynamic assessment of non- culprit lesions to better predict adverse event outcomes in diabetes mellitus patients: COMBINE (OCT-FFR) trial database (NCT02989740), we performed a detailed assessment OCT qualitative and quantitative variables in TCFA carrying diabetes mellitus (DM) patients with vs. without MACE during follow-up. MACEs were defined as a composite of cardiac death, target vessel myocardial infarction, clinically driven target lesion revascularization, and hospitalization for unstable angina. From the 390 fractional flow reserve (FFR)-negative DM patients, 98 (25.2%) had ≥1 OCT-detected TCFA, of which 13 (13.3%) had MACE and 85 (86.7%) were event-free (non-MACE). The baseline characteristics were similar between both groups; however, a smaller minimal lumen area (MLA) and lower mean FFR value were observed in MACE group (1.80 vs. 2.50 mm2, P = 0.01, and 0.85 vs. 0.89, P = 0.02, respectively). Prevalence of healed plaque (HP) was higher in the MACE group (53.85 vs. 21.18%, P = 0.01). TCFA were predominantly located proximal to the MLA. TCFA area was smaller in the MACE group, while no difference was observed regarding the lesion area. Conclusion: Within TCFA carrying patients, a smaller MLA, lower FFR values, and TCFA location adjacent to a HP were associated with future MACE. Carpet-like measured lesion area surface was similar, while the TCFA area was smaller in the MACE arm, and predominantly located proximal to the MLA.

Background. In-stent restenosis (ISR) is the gradual narrowing of the vessel lumen after coronary stent implantation due to the increase in vascular smooth muscle cell proliferation. Vascular endothelial growth factor (VEGF) protein plays an important role in this process. Our aim was to analyze the association of single nucleotide polymorphisms of the VEGF gene (rs2010963 and rs6999447) with the occurrence of ISR after coronary artery bare metal stent (BMS) implantation. Methods. 205 patients with a history of BMS implantation and a repeated coronarography were prospectively enrolled. Patients were assigned to diffuse restenosis group (n=105) and control group (n=100) and VEGF genotypes were determined. Results. Diffuse ISR was significantly more frequently observed in patients with homozygous normal genotype of rs2010963 polymorphism, and this polymorphism was independently associated with diffuse ISR. Conclusions. RS2010963 is associated with higher incidence of development of diffuse coronary ISR in patients treated with BMS implantation.

In-stent restenosis occurs in 10–30% of patients following bare metal stent (BMS) implantation and has various risk factors. Mannose-binding lectin (MBL) is known to have effect on the progression of atherosclerosis. Single nucleotide polymorphisms (SNP) of the MBL2 gene intron 1 (codon 52, 54, 57) are known to modulate the bioavailability of the MBL protein. Our aim was to identify the association of these polymorphisms of the MBL gene in the occurrence of in-stent restenosis after coronary artery bare metal stent implantation. In a non-randomized prospective study venous blood samples were collected after recoronarography from 225 patients with prior BMS implantation. Patients were assigned to diffuse restenosis group and control group based on the result of the coronarography. MBL genotypes were determined using quantitative real-time PCR. Proportion of different genotypes was compared and adjusted with traditional risk factors using multivariate logistic regression. Average follow-up time was 1.0 (+ − 1.4) year in the diffuse restenosis group (N = 117) and 2.7 (+ − 2.5) years in the control group (N = 108). The age, gender distribution and risk status was not different between study groups. Proportion of the MBL variant genotype was 26.8% (29 vs. 79 normal homozygous) in the control group and 39.3% (46 vs. 71 normal homozygous) in the restenosis group (p = 0.04). In multivariate analysis the mutant allele was an independent risk factor (OR = 1.96, p = 0.03) of in-stent restenosis. MBL polymorphisms are associated with higher incidence of development of coronary in-stent restenosis. The attenuated protein function in the mutant allelic genotype may represent the underlying mechanism.