Yu Ishikawa

Clinical and pathological characteristics of homogeneous and nonhomogeneous tissue of in-stent restenosis visualized by optical coherence tomography.

BackgroundAlthough it is known that in-stent restenosis (ISR) patterns appear homogeneous or nonhomogeneous by optical coherence tomography (OCT), interpretations of the ISR inflammatory response, of the OCT image, and its pathological implications are unclear. The aim of this study was to use OCT to characterize ISR and its inflammatory index in patients after coronary stenting. MethodsOCT was performed at follow-up in 100 angiographic ISR lesions. ISR lesions were divided into two groups: (a) homogeneous (n=48) and (b) nonhomogeneous (n=52) image groups. We assessed the ISR images produced by OCT for tissue heterogeneity and neo-intimal hyperplasia using the normalized standard deviation of OCT signal-intensity (OCT-NSD) observed in neo-intimal hyperplasia tissue. In some patients with a nonhomogeneous OCT image, we collected pathological tissue. ResultsThe prevalence of drug-eluting stents was 48% in the nonhomogeneous group and 29% in the homogeneous group (P=0.05). The OCT-NSD value in the nonhomogeneous group (0.223±0.019) was significantly higher than that in the homogeneous group (0.203±0.025; P<0.0001). Pathological tissue showed fibrin thrombi with infiltrating macrophage in 12 cases of nonhomogeneous ISR. The area under the receiver operating characteristic curve for the prediction of a nonhomogeneous image was 0.73 for OCT-NSD (95% confidence interval: 0.62–0.83: P<0.0001). The odds ratio for the prediction of a nonhomogeneous image was 3.47 (95% confidence interval: 1.18–10.2: P=0.02) for smoking by logistic regression analysis. ConclusionNonhomogeneous ISR visualized by OCT showed a high OCT-NSD value, which was a useful predictor for nonhomogeneous images. Moreover, the nonhomogeneous ISR image visualized by OCT may show chronic inflammation and fibrin thrombi.

Very late stent thrombosis after paclitaxel-eluting stent implantation with full neointimal tissue coverage visualized by optical coherence tomography

We present findings of a very late stent thrombosis (VLST) involving paclitaxel-eluting stents (PESs) that were fully covered by thin neointima, visualized by optical coherence tomography (OCT) in a patient receiving dual antiplatelet therapy. A 69-year-old Japanese man had been treated with 2 overlapping PESs for chronic coronary artery disease in the proximal right coronary artery. A follow-up coronary computed tomography angiography showed no restenosis in the stent site, and the result of stress myocardial perfusion imaging showed no ischemic changes. Seventeen months after the percutaneous coronary intervention, he was transported to our clinic with a diagnosis of acute myocardial infarction. Emergency coronary angiography showed a total occlusion at the overlapping site of the 2 PESs. After thrombus aspiration therapy, the OCT image revealed a thin layer of neointimal tissue covering the stent struts with no stent malapposition or fracture. There was no plaque rupture site or intracoronary thrombus. Histopathologic study of an aspirated red thrombus revealed massive amounts of inflammatory infiltrates including eosinophils and neutrophils within the fibrin clot. These findings suggested the possibility that the patients allergic and inflammatory reactions may have caused the onset of VLST. <Learning objective: To recognize the relationship between in stent OCT findings of neointima and pathological findings of the thrombus at the VLST after PES implantation.>.

A Low Early High-density Lipoprotein Cholesterol Level is an Independent Predictor of In-hospital Death in Patients with Acute Coronary Syndrome

Objective In patients with acute coronary syndrome (ACS), low high-density lipoprotein cholesterol (HDL-C) levels in samples collected after an overnight fast are diagnostic indicators and well-established predictors of adverse outcomes. However, the relationship between the HDL-C levels in samples collected just after arrival (early HDL-C) and in-hospital mortality remains unknown. The purposes of the present ACS study were to (1) evaluate the association between the early HDL-C levels of patients and in-hospital mortality and (2) compare the early HDL-C level with other well-known determinants associated with in-hospital mortality. Methods This retrospective study surveyed 638 consecutive ACS patients and then assessed the possible determinants of in-hospital mortality. All initial blood samples, including that for early HDL-C, were drawn within one hour of arrival. Results In the present study, the overall in-hospital mortality was 5.9%. A multivariable analysis showed that a low early HDL-C [odds ratio (OR) 2.53, 95% confidence interval (CI) 1.14-5.62], elevated troponin T (OR 4.40, 95% CI 1.26-15.29) and high Killip class (OR 15.41, 95% CI 7.29-32.59) were independent predictors of in-hospital mortality. A Kaplan-Meier survival analysis indicated that there the in-hospital outcome for the low early HDL-C group was significantly worse than that for the high early HDL-C group (age- and gender-adjusted hazard ratio 2.40, 95% CI 1.15-5.00, p=0.02). Conclusion ACS patients with low early HDL-C levels had higher in-hospital mortalities than those who did not have low early HDL-C levels. In addition to the already well-known determinants, low early HDL-C should also be considered as an independent predictor of in-hospital mortality in ACS patients who present to a cardiac care unit.

Optimized interpretation of fractional flow reserve derived from computed tomography: Comparison of three interpretation methods

BACKGROUND An optimal system for interpreting fractional flow reserve (FFR) values derived from CT (FFRCT) is lacking. We sought to evaluate performance of three FFRCT measurements in detecting ischemia by comparing them with invasive FFR. METHODS For 73 vessels in 50 patients who underwent coronary CT angiography (CCTA) and FFRCT analysis followed by invasive FFR, the greatest diameter stenosis on CCTA, FFRCT difference between distal and proximal to the stenosis (ΔFFRCT), FFRCT 2 cm distal to the stenosis (lesion-specific FFRCT), and the lowest FFRCT in distal vessel tip were calculated. Significant obstruction (≥50% diameter stenosis) and ischemia (lesion-specific FFRCT ≤0.80, the lowest FFRCT ≤0.80, or ΔFFRCT ≥0.12 based on the greatest Youden index) were compared with invasive FFR (≤0.80). RESULTS Forty (55%) vessels demonstrated ischemia during invasive FFR. On multivariable generalized estimating equations, ΔFFRCT (odds ratio [OR] 10.2, p < 0.01) remained a predictor of ischemia over CCTA (OR 2.9), lesion-specific FFRCT (OR 3.1), and the lowest FFRCT (OR 0.9) (p > 0.05 for all). Area under the curve (AUC) of ΔFFRCT (0.86) was higher than CCTA (0.66), lesion-specific FFRCT (0.71), and the lowest FFRCT (0.65) (p < 0.01 for all). Addition of each FFRCT measure to CCTA showed improvement of AUC and significant net reclassification improvement (NRI): ΔFFRCT (AUC 0.84, NRI 1.24); lesion-specific FFRCT (AUC 0.77, NRI 0.83); and the lowest FFRCT (AUC 0.76, NRI 0.59) (p < 0.01 for all). CONCLUSIONS Compared with diameter stenosis, ΔFFRCT, lesion-specific FFRCT, and the lowest FFRCT improved ischemia discrimination and reclassification, with ΔFFRCT being superior in identifying and discriminating ischemia.