The optimal duration of dual antiplatelet therapy for acute myocardial infarction is controversial because the bleeding risk outweighs the thromboembolic risk. We hypothesized that an in-stent ...thrombus (IS-thrombus) detected by coronary angioscopy (CAS) after stent implantation would be associated with high bleeding risk.
This study included 208 patients who underwent CAS at 2 weeks after stent implantation for an acute myocardial infarction. The study was approved by the ethics committee at the Nihon University Itabashi Hospital (reference number RK-200714-10).
In 84 patients, in whom no IS-thrombus was identified in the culprit vessel using CAS, the major bleeding event rate was significantly higher than that in patients with IS-thrombi (n = 124). However, no difference was detected in major adverse cardiovascular events (MACE; stroke, hospitalization for a non-fatal myocardial infarction/unstable angina, target lesion revascularization, and cardiovascular death). After adjustments by the propensity score based on patient characteristics, the absence of IS-thrombi remained an independent predictor of major bleeding events (hazard ratio 4.73, 95% confidence interval 2.04–11.00, p < 0.001).
The absence of CAS-detected IS-thrombi in the subacute phase was independently associated with future major bleeding events, but not with MACE. These findings may help optimize the duration of dual antiplatelet therapy.
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•Absence of in-stent thrombi detected by coronary angioscopy is linked to future bleeding.•Absence of in-stent thrombi is not associated with major adverse cardiovascular events.•Presence vs. absence of thrombi may suggest the duration of the dual antiplatelet therapy.
Aim: Coronary plaque rupture is the main cause of acute coronary syndrome (ACS), but the role of blood flow features around plaque rupture for ACS is still unknown. The present study aimed to assess ...the relationship between the geometric configuration of ruptured plaque and ACS occurrence using computational fluid dynamics (CFD) by moving particle method in patients with coronary artery disease. Methods: In this study, 45 patients with coronary artery disease who underwent three-dimensional intravascular ultrasound (IVUS) and had a coronary ruptured plaque (24 plaques with provoked ACS, 21 without) were included. To compare the difference in blood flow profile around ruptured plaque between the patients with and without ACS, the IVUS images were analyzed via the novel CFD analysis. Results: There were no significant differences in localized flow profile around ruptured plaque between the two groups when the initial particle velocity was 10.0 cm/s corresponded to a higher coronary flow velocity at ventricular diastole. However, when it was 1.0 cm/s corresponded to lower coronary flow velocity at ventricular systole, particles with lower velocity (0 ≤ V ≤ 5 cm/s) were more prevalent around ACS-PR (p=0.035), whereas particles with higher velocity (10 ≤ V ≤ 20 cm/s) were more often detected in silent plaque ruptures (p=0.018). Conclusions: Three-dimensional IVUS revealed that coronary plaque rupture was a complex one with a wide variety of its stereoscopic configuration, leading to various patterns of the local coronary flow profile. A novel CFD analysis suggested that the local flow was more stagnant around ACS-provoked ruptures than in silent ones.
Objective
The aim of this study was to compare how prasugrel and clopidogrel affect platelet aggregation reactivity, cardiac enzyme release, cardiac remodeling, and the formation of in‐stent thrombi ...after primary percutaneous coronary intervention (PCI).
Background
The advantages of using prasugrel over clopidogrel in cardiac injury following acute coronary syndrome (ACS) remain unclear.
Methods
A total of 78 ACS patients were randomly allocated into clopidogrel (300 mg loading/75 mg maintenance) or prasugrel (20 mg loading/3.75 mg maintenance) treatment groups, followed by undergoing primary PCI. Platelet reactivity and cardiac enzymes were measured before and after primary PCI. Moreover, cardiac function was measured by ultrasound echocardiography and coronary angioscopic observation was after primary PCI up to 8 months later.
Results
Antiplatelet reactivity in the prasugrel treatment group reached optimal levels (P2Y12 reaction units PRU less than 262) immediately after the administration and was maintained even at 8 months, independently of the CYP2C19 genotype. Prasugrel treatment significantly suppressed creatine kinase elevation compared to clopidogrel treatment (median value 404 IU/L to 726 IU/L vs. 189 IU/L to 1,736 IU/L, p = 0.018 for maximum values) and reduced left ventricular mass (217.2–168.8 g in prasugrel, p = 0.045; 196.9–176.4 g in clopidogrel, p = 0.061). There were no significant differences in the incidence of in‐stent attached thrombi between the two groups.
Conclusions
Compared to clopidogrel, prasugrel produced a stable platelet aggregation inhibitory effect in patients with ACS regardless of CYP2C19 genotype, reduced cardiac enzyme release, and prevented cardiac remodeling after ACS.
Aim: According to recent clinical trials, a combination of direct oral anticoagulants with antiplatelet drugs is often recommended for atrial fibrillation patients who receive drug-eluting stents ...(DESs). Although the optimal combination comprises direct factor Xa inhibitors and a P2Y12 receptor antagonist (or aspirin), their influence on vascular responses to DESs remains unclear. Methods: Pigs were given either aspirin and clopidogrel (dual antiplatelet therapy DAPT group), aspirin and rivaroxaban (AR group), or clopidogrel and rivaroxaban (CR group), followed by everolimus-eluting stent (Promus Element) implantation into the coronary artery. Stented coronary arteries were evaluated via intravascular optical coherence tomography (OCT) and histological analysis at 1 and 3 months. Results: OCT revealed lower neointimal thickness in the DAPT group and comparable thickness among all groups at 1 and 3 months, respectively. Histological analyses revealed comparable neointimal area among all groups and the smallest neointimal area in the CR group at 1 and 3 months, respectively. In the DAPT and AR groups, the neointima continued to grow from 1 to 3 months. A shortened time course for neointima growth was observed in the CR group, with rapid growth within a month (maintained for 3 months). A higher incidence of in-stent thrombi was observed in the AR group at 1 month; no thrombi were found in either group at 3 months. More smooth muscle cells with contractile features were found in the CR group at both 1 and 3 months. Conclusions: Our results proved the noninferiority of the combination of rivaroxaban with an antiplatelet drug, particularly the dual therapy using rivaroxaban and clopidogrel, compared to DAPT after DES implantation.
Aims: Smaller low-density lipoprotein (LDL) particle size has been suggested to result in the development of endothelial dysfunction, atherosclerosis, and in-stent restenosis (ISR); however, little ...is known regarding the impact of the LDL particle size on the neointima formation leading to ISR after everolimus-eluting stent (EES) implantation. Methods: In this study, we have included 100 patients to examine the relationship between an LDL-C/apolipoprotein B (Apo B) ≤ 1.2, reportedly representing the LDL particle size, and the neointimal characteristics using optical coherence tomography (OCT) and coronary angioscopy (CAS) during the follow-up coronary angiography (CAG) period (8.8±2.5 months) after EES implantation. We divided them into two groups: LDL-C/Apo B ≤ 1.2 group (low LDL-C/Apo B group, n=53) and LDL-C/Apo B ＞1.2 group (high LDL-C/Apo B group, n=47). Results: The low LDL-C/Apo B group had a significantly larger neointimal volume (12.8±5.3 vs. 10.3±4.9 mm3, p=0.021) and lower incidence of a neointimal homogeneous pattern (71 vs. 89 %), higher incidence of a neointimal heterogeneous pattern (25 vs. 9 %) (p=0.006) and higher prevalence of macrophage accumulation (9 vs. 2 %) (p=0.030) as assessed via OCT, and, as per the CAS findings, a higher prevalence of yellow grade ≥ 2 (grade 2; adjusted residual: 2.94, grade 3; adjusted residual: 2.00, p=0.017) than the high LDL-C/Apo B group. Conclusions: A low LDL-C/Apo B ratio was found to be strongly associated with neointimal proliferation and neointimal instability evidenced chronically by OCT and CAS. An LDL-C/Apo B ≤ 1.2 will be of aid in terms of identifying high-risk patients after EES implantation.
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