Takeyoshi Kameyama

Optical Coherence Tomography Predictors for Edge Restenosis After Everolimus-Eluting Stent Implantation

Background—Stent edge restenosis (SER) remains a potential limitation of drug-eluting stents. The aim of this study was to determine optical coherence tomography (OCT) predictors for angiographic late SER after everolimus-eluting stent implantation. Methods and Results—We retrospectively analyzed 319 patients who underwent OCT immediately after everolimus-eluting stent implantation and scheduled 9- to 12-month follow-up angiography. The binary angiographic SER rate was 10% (32/319) in the patients, 8.4% (32/382) in lesions, and 4.4% (33/744) in stent edge segments. In the stent edge segments at post stenting, OCT-derived lipidic plaque (61% versus 20%; P<0.001) was more often observed in the SER group, and OCT-measured minimum lumen area (4.13±2.61 versus 5.58±2.46 mm2; P=0.001) was significantly smaller in the SER group compared with the non-SER group. Multivariate analysis identified lipidic plaque (odds ratio: 5.99; 95% confidence interval: 2.89–12.81; P<0.001) and minimum lumen area (odds ratio: 0.64; 95% confidence interval: 0.42–0.96; P=0.029) as independent predictors of binary SER. Receiver-operating characteristic analysis demonstrated that lipid arc of 185° (sensitivity: 71%; specificity: 72%; area under the curve: 0.761) and minimum lumen area of 4.10 mm2 (sensitivity: 67%; specificity: 77%; area under the curve: 0.787) were optimal cutoff values for predicting ischemia-driven SER. Conclusions—The present OCT study demonstrated that lipidic plaque and minimum lumen area in the stent edge segments at post stenting were associated with late SER after everolimus-eluting stent implantation. OCT provides valuable information to determine an appropriate landing zone for stent implantation.

Local Matrix Metalloproteinase 9 Level Determines Early Clinical Presentation of ST-Segment–Elevation Myocardial Infarction

Objective—Early clinical presentation of ST-segment–elevation myocardial infarction (STEMI) and non–ST-segment–elevation myocardial infarction affects patient management. Although local inflammatory activities are involved in the onset of MI, little is known about their impact on early clinical presentation. This study aimed to investigate whether local inflammatory activities affect early clinical presentation. Approach and Results—This study comprised 94 and 17 patients with MI (STEMI, 69; non-STEMI, 25) and stable angina pectoris, respectively. We simultaneously investigated the culprit lesion morphologies using optical coherence tomography and inflammatory activities assessed by shedding matrix metalloproteinase 9 (MMP-9) and myeloperoxidase into the coronary circulation before and after stenting. Prevalence of plaque rupture, thin-cap fibroatheroma, and lipid arc or macrophage count was higher in patients with STEMI and non-STEMI than in those with stable angina pectoris. Red thrombus was frequently observed in STEMI compared with others. Local MMP-9 levels were significantly higher than systemic levels (systemic, 42.0 [27.9–73.2] ng/mL versus prestent local, 69.1 [32.2–152.3] ng/mL versus poststent local, 68.0 [35.6–133.3] ng/mL; P<0.01). Poststent local MMP-9 level was significantly elevated in patients with STEMI (STEMI, 109.9 [54.5–197.8] ng/mL versus non-STEMI: 52.9 [33.0–79.5] ng/mL; stable angina pectoris, 28.3 [14.2–40.0] ng/mL; P<0.01), whereas no difference was observed in the myeloperoxidase level. Poststent local MMP-9 and the presence of red thrombus are the independent determinants for STEMI in multivariate analysis. Conclusions—Local MMP-9 level could determine the early clinical presentation in patients with MI. Local inflammatory activity for atherosclerosis needs increased attention.

Reduction of in-stent thrombus immediately after percutaneous coronary intervention by pretreatment with prasugrel compared with clopidogrel: An optical coherence tomography study.

BACKGROUND Prasugrel is a new-generation thienopyridine antiplatelet agent that provides more consistent and prompt platelet inhibition than clopidogrel. The aim of this study was to compare in-stent thrombus inhibition effect of pretreatment with prasugrel and clopidogrel by using optical coherence tomography (OCT) immediately after percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). METHODS We performed OCT immediately after PCI in 108 ACS patients pretreated with either prasugrel (n=51) or clopidogrel (n=57). OCT detected thrombus/plaque protrusion in all stented segments. RESULTS Although stent volume (190.4±119.1mm3 vs. 189.4±95.8mm3, p=0.961), mean stent area (6.9±2.9mm2 vs. 7.1±2.0mm2, p=0.772), and minimum stent area (5.6±2.7mm2 vs. 5.4±1.7mm2, p=0.554) were not different between the two groups, in-stent thrombus/plaque protrusion volume (1.8±2.9mm3 vs. 4.5±5.3mm3, p=0.002), mean in-stent thrombus/plaque protrusion area (0.1±0.1mm2 vs. 0.2±0.2mm2, p=0.005), and maximum in-stent thrombus/plaque protrusion area (0.5±0.7mm2 vs. 0.8±0.6mm2, p=0.007) were significantly smaller in the prasugrel group compared with the clopidogrel group. CONCLUSIONS Pretreatment with prasugrel was associated with significantly reduced in-stent thrombus/plaque protrusion immediately after PCI for ACS compared with that with clopidogrel.

Prognosis of spontaneous coronary artery dissection treated by percutaneous coronary intervention with optical coherence tomography

BACKGROUND Although about half of patients with spontaneous coronary artery dissection (SCAD) face ongoing necrosis, conservative therapy is recommended due to a high complication rate in angiography-guided percutaneous coronary intervention (PCI). The aim of this study was to investigate clinical outcomes of SCAD treated by optical coherence tomography (OCT)-guided PCI. METHODS This study consisted of consecutive 306 patients with acute coronary syndrome (ACS) who underwent OCT-guided PCI. Based on the culprit lesion morphology by OCT, patients were assigned to four groups: a SCAD group, a plaque rupture (PR) group, a calcified nodule (CN) group, and an undetermined etiology (UE) group. Successful PCI was defined as thrombolysis in myocardial infarction flow grade 3 in final angiography without any complications. Primary endpoint was defined as occurrence rate of major adverse cardiac events (MACE) including cardiac death, myocardial infarction, and unstable angina pectoris. RESULTS OCT revealed 12 SCADs, 149 PRs, 16 CNs, and 129 UEs, respectively. No significant difference was observed in the success rate of PCI (SCAD 91.7%, PR 85.2%, CN 81.2%, UE 86.8%, p=0.88), while wire repositioning was needed in 2 SCAD cases (p<0.01). The mean follow-up periods were 17.1±13.3 months. No significant difference was observed in MACE among the groups (p=0.56). CONCLUSIONS The clinical outcomes of OCT-guided PCI for SCAD were favorable, as well as those for other ACS etiologies. OCT-guided PCI could become a therapeutic option for SCAD compromised with ongoing necrosis.

Impact of functional focal versus diffuse coronary artery disease on bypass graft patency

BACKGROUND Pressure guidewire pullback recording can differentiate between functional focal and diffuse disease types in coronary artery disease. The aim of this study was to compare the outcome of coronary artery bypass graft (CABG) patency between patients with functional focal versus diffuse disease types in recipient coronary arteries. METHODS AND RESULTS We investigated 89 patients who underwent pressure guidewire pullback in the left anterior descending (LAD) artery before CABG using internal mammary artery (IMA). Based on the pressure guidewire pullback data, the LAD lesions were classified into functional focal disease (abrupt pressure step-up; n=58) or functional diffuse disease (gradual pressure increase; n=31). Follow-up computed tomography (CT) angiography was conducted within 1year after CABG to assess the bypass graft patency. Pre CABG, LAD angiographic percent diameter stenosis (57±10% vs. 54±12%, p=0.228) and fractional flow reserve (FFR) (0.68±0.07 vs. 0.69±0.07, p=0.244) were not different between the functional focal and diffuse disease groups. The CABG procedure characteristics were similarly comparable between the two groups. In the follow-up CT angiography after CABG, occlusion or string sign of the IMA graft to LAD was more frequently observed in the functional diffuse disease group than in the functional focal disease group (26% vs. 7%, p=0.021). CONCLUSION In CABG, functional diffuse disease in the recipient coronary artery was associated with an increased risk of the graft failure in comparison with functional focal disease.

TCT-542 Usefulness of QFR measurement for non-culprit lesion of ACS patients

The use of fractional flow reserve (FFR) for assessing intermediate coronary lesions has gained worldwide acceptance in the cardiology community. The severity of non-culprit coronary artery stenosis during the acute phase of acute coronary syndrome (ACS) also can be reliably assessed by FFR. FFR

Diagnostic Accuracy of Quantitative Flow Ratio for Assessing Myocardial Ischemia in Prior Myocardial Infarction

BACKGROUND A novel index of the functional severity of coronary stenosis, quantitative flow ratio (QFR), may not consider the amount of viable myocardium in prior myocardial infarction (MI) because QFR is calculated from 3D quantitative coronary angiography.Methods and Results:We analyzed QFR (fixed-flow QFR [fQFR] and contrast-flow QFR [cQFR]) and fractional flow reserve (FFR) in prior-MI-related coronary arteries (n=75) and non-prior-MI-related coronary arteries (n=75). Both fQFR and cQFR directly correlated with FFR in the prior-MI-related coronary arteries (fQFR: r=0.84, P<0.001; and cQFR: r=0.88, P<0.001) and the non-prior-MI-related coronary arteries (fQFR: r=0.91, P<0.001; and cQFR: r=0.94, P<0.001). fQFR was significantly smaller than FFR in the prior-MI-related coronary arteries (0.73±0.14 vs. 0.79±0.11, P=0.002), but there was no significant difference between fQFR and FFR in the non-prior-MI-related coronary arteries. The value of cQFR minus FFR was significantly lower in the prior-MI-related coronary arteries compared with the non-prior-MI-related coronary arteries (-0.02±0.06 vs. 0.00±0.04, P=0.010). The diagnostic accuracy of fQFR ≤0.8 and cQFR ≤0.8 for predicting FFR ≤0.80 was numerically lower in the prior-MI-related coronary arteries compared with the non-prior-MI-related coronary arteries (fQFR: 77% vs. 87%; and cQFR: 87% vs. 92%). CONCLUSIONS When FFR is used as the gold standard, the accuracy of QFR for assessing the functional severity of coronary stenosis might be reduced in the prior-MI-related coronary arteries compared with non-prior-MI-related coronary arteries.

Effects of intravenous bolus injection of nicorandil on renal artery flow velocity assessed by color Doppler ultrasound

BACKGROUND Previous animal studies have shown that a potassium channel opener, nicorandil, provokes vasodilation in renal microvasculature and increases renal blood flow. We conducted a clinical study that aimed to evaluate the effect of nicorandil on renal artery blood flow in comparison with nitroglycerin by using color Doppler ultrasound. METHODS The present study enrolled 40 patients with stable coronary artery disease who had no renal arterial stenosis and renal parenchymal disease. The patients received intravenous administration of nicorandil (n=20) or nitroglycerin (n=20). Before and after the administration, renal artery blood flow velocity was measured by color-guided pulsed-wave Doppler. RESULTS The peak-systolic, end-diastolic, and mean renal artery blood flow velocities before the administration were not different between the nicorandil group and the nitroglycerin group. The peak-systolic (79±15cm/s to 99±21cm/s, p<0.001; and 78±19cm/s to 85±19cm/s, p=0.004), end-diastolic (22±5cm/s to 28±8cm/s, p<0.001; and 24±6cm/s to 26±6cm/s, p=0.005) and mean (41±6cm/s to 49±9cm/s, p<0.001; and 43±9cm/s to 45±9cm/s, p=0.009) renal artery flow velocities increased significantly in either group. The nominal changes in the peak-systolic (20±10cm/s vs. 7±8cm/s, p<0.001), end-diastolic (5±4cm/s vs. 2±3cm/s, p=0.001), and mean (8±5cm/s vs. 2±2cm/s, p<0.001) renal artery blood flow velocities were significantly greater in the nicorandil group compared with the nitroglycerin group. CONCLUSION Intravenous nicorandil increased renal artery blood flow velocity in comparison with nitroglycerin. Nicorandil has a significant effect on renal hemodynamics.

TCT-580 Optical coherence tomography predictors for edge restenosis after everolimus-eluting stent implantation

Restenosis in reference segments adjacent to the proximal and distal border of the stent (so-called “stent edge restenosis [SER]”) remains a potential limitation of drug-eluting stents. The aim of this study was to determine optical coherence tomography (OCT) predictors for angiographic late SER

Assessment of Vascular Response after Stent Implantation by Intracoronary Optical Coherence Tomography

Optical coherence tomography (OCT) is a high resolution (10-20 μm) imaging modality that provides microscopic visualization of the coronary artery including vascular response after stent implantation. Compared to conventional intravascular ultrasound, OCT can more clearly identify findings immediately after stent implantation, such as tissue protrusion, stent edge dissection, and incomplete stent strut apposition. Furthermore, OCT allows clinicians to accurately assess the late acquired stent malapposition and strut coverage which could be a surrogate marker for stent thrombosis after drug-eluting stent (DES) implantation. OCT can evaluate not only the extent and amount of neointima but also the tissue characteristics of neointimal hyperplasia. Morphological OCT evaluation of restenosis tissue may offer important information about treatment strategies for in-stent restenosis lesion as well as the acute/mid-term clinical outcome after percutaneous coronary intervention. In addition, in-stent neoatherosclerosis, which are associated with very late stent failure, including stent thrombosis and restenosis, frequently has the following OCT findings; lipid-rich neointima, microvascular proliferation, and neointimal disruption. Thus, the high resolution imaging of OCT has provided important insights into the vascular response immediately and late after stent implantation.