Hiroaki Ohya

Optical Coherence Tomography–Defined Plaque Vulnerability in Relation to Functional Stenosis Severity and Microvascular Dysfunction

OBJECTIVESnThis study sought to investigate the relationship of unstable plaque features with physiological lesion severity and microvascular dysfunction.nnnBACKGROUNDnThe functional severity of epicardial lesions and microvascular dysfunction are both related to adverse clinical outcomes.nnnMETHODSnWe investigated 382 de novo intermediate and severe coronary lesions in 340 patients who underwent optical coherence tomography, fractional flow reserve (FFR), and index of microcirculatory resistance (IMR) examinations. Lesions were divided into tertiles based on either FFR or IMR values. The optical coherence tomography findings were compared among the tertiles of FFR and IMR. Each tertile was defined as follows: FFR-T1 (FFRxa0<0.74), FFR-T2 (0.74xa0≤ FFRxa0≤0.81), and FFR-T3 (FFR >0.81); and IMR-T1 (IMRxa0≥25), IMR-T2 (15xa0< IMRxa0<25), and IMR-T3 (IMRxa0≤15).nnnRESULTSnNo significant relationship was observed between FFR and IMR. The prevalence of optical coherence tomography-defined thin-cap fibroatheroma (TCFA) was significantly greater in IMR-T1 than in IMR-T2 and IMR-T3. An overall significant difference in the prevalence of TCFAs was detected among FFR tertiles, although no pairwise comparison revealed statistical significance. The prevalence of ruptured plaque was significantly greater in IMR-T1 than in IMR-T2 and IMR-T3, although no significant difference was observed between FFR tertiles. Multivariate analysis showed that FFR and IMR were independent predictors of the prevalence of TCFAs (odds ratio: 0.036; 95% confidence interval: 0.004 to 0342; pxa0= 0.004; and odds ratio: 1.034; 95% confidence interval: 1.014 to 1.054; pxa0= 0.001, respectively).nnnCONCLUSIONSnLower FFR and higher IMR values were independent predictors of the presence of a TCFA in angiographically intermediate-to-severe stable lesions or nonculprit lesions in acute coronary syndrome.

CLINICAL SIGNIFICANCE OF LIPID-RICH PLAQUE WITH INTACT FIBROUS CAP DEFINED BY OPTICAL COHERENCE TOMOGRAPHY IN ACUTE MYOCARDIAL INFARCTION

Lipid-rich plaque (LRP) is thought to be a precursor to cardiac events. Intact fibrous cap (IFC) has different underlying pathology in comparison with plaque rupture. Nevertheless, clinical significance of LRP with IFC in acute myocardial infarction (AMI) culprit lesions has not fully elucidated in

Relationship between optical coherence tomography-derived morphological criteria and functional relevance as determined by fractional flow reserve

BACKGROUNDnAlthough several previous studies have indicated that optical coherence tomography (OCT)-derived minimal lumen area (MLA) correlates with fractional flow reserve (FFR) severity, other morphologic criteria for functionally significant coronary stenosis assessed by FFR have not been fully elucidated. This study aimed to identify OCT-based morphological predictors of physiologically significant ischemia assessed by FFR in angiographically intermediate coronary lesions.nnnMETHODSnWe investigated 194 de novo intermediate coronary lesions in 178 patients with stable angina pectoris who underwent OCT imaging and FFR measurement. The lesions were divided into two groups according to an FFR threshold: ischemia group, FFR <0.75 (n=69) and non-ischemia group, FFR ≥0.75 (n=125). Clinical characteristics, angiographic, and OCT findings were compared between these two groups. Predictors of significant ischemia defined as FFR <0.75 were identified by logistic regression analyses.nnnRESULTSnPatient age, statin use, lesion in left anterior descending artery (LAD), OCT-derived MLA, and lipid volume index (LVI) (averaged lipid arc multiplied by lipid length) were independent predictors of FFR <0.75 in multivariate logistic regression analysis. Receiver operating characteristic analysis suggested that age <64 years old, OCT-derived MLA ≤1.39mm2, and LVI ≥733 are the best cut-off values for predicting FFR <0.75. Multiple logistic regression models, including the MLA combined with the LAD location, LVI, age, and statin use, provided superior predictive efficacy for physiologically significant ischemia compared with the model that only employed MLA.nnnCONCLUSIONSnInformation on OCT-derived LVI and lesion locations facilitates better identification of coronary lesions that cause ischemia than OCT-derived MLA analysis alone.