Association of LDL-C level with neoatherosclerosis and plaque vulnerability in patients with late restenosis: an optical coherence tomography study.

Neoatherosclerosis (NA) is a significant contributor to late stent failure; however, predictors of late in-stent restenosis (ISR) with NA have not been systematically reported. This study aimed to identify predictors of NA incidence and plaque vulnerability in patients with late ISR and the role of low-density lipoprotein cholesterol (LDL-C) levels in this process. A total of 216 patients with 216 lesions who underwent optical coherence tomography (OCT) before interventional procedure for late drug-eluting stent ISR were enrolled and divided into NA and non-NA groups based on OCT findings. Results showed that higher LDL-C levels were associated with NA, thin-cap fibroatheroma (TCFA), intimal disruption, plaque erosion, and thrombosis. Multivariate regression analysis revealed that the LDL-C level was an independent risk factor for NA and TCFA. The LDL-C levels exhibited a significant predictive value for NA and TCFA, surpassing other factors such as stent age and other lipid types. In conclusion, a high LDL-C level is an independent predictor of NA incidence and plaque vulnerability in patients with late ISR.

Role of Dual-Acquisition Noninvasive Cardiac CT Imaging for the Detection of Vasospastic Angina.

BACKGROUND: Vasospastic angina (VSA) is characterized by chest pain at rest with transient ischemic electrocardiographic changes in the ST segment, and a prompt response to nitrates. Vasospastic angina is among the most frequent of the coronary artery diseases in Asia, and coronary computed tomography angiography (CCTA) may become available as a non-invasive diagnosis method. METHODS: We prospectively enrolled 100 patients with suspected vasospastic angina at two centers from 2018 to 2020. All patients underwent baseline CCTA without a vasodilator in the early morning followed by catheterized coronary angiography and spasm testing. CCTA with intravenous infusion of nitrate (IV) was repeated within 2 weeks of baseline CCTA. Vasospastic angina as detected by CCTA was defined as significant stenosis (≥50%) with negative remodeling without definite plaques or diffuse small diameter (<2 mm) of a major coronary artery with a beaded appearance on baseline CT that completely dilated on IV nitrate CT. We analyzed diagnostic performance of dual-acquisition CCTA for the detection of vasospastic angina. RESULTS: The patients were categorized into three groups according to their provocation test result (negative, n = 36; probable positive, n = 18; positive, n = 31). The diagnostic accuracy in terms of CCTA per patient had a sensitivity of 55% (95% CI, 40-69), specificity of 89% (95% CI, 74-97), positive predictive value (PPV) of 87% (95% CI, 72-95), and negative predictive value (NPV) of 59% (95% CI, 51-67). CONCLUSIONS: Dual-acquisition CCTA can support the non-invasive detection of vasospastic angina with relatively good specificity and PPV. CCTA was helpful for non-invasive screening of variant angina.

Differences in Optimal Platelet Reactivity after Potent P2Y12 Inhibitor Treatment in Acute Coronary Syndrome Patients Undergoing Percutaneous Coronary Intervention.

Background: East Asian patients receiving treatment with the potent P2Y12 inhibitors prasugrel or ticagrelor experience more potent platelet inhibition than with clopidogrel. Methods: This study investigated differences in OPR rates with reduced doses of prasugrel (n = 38) or ticagrelor (n = 40) for maintenance therapy in 118 Korean ACS patients who had undergone PCI, in comparison to conventional-dose clopidogrel (n = 40). We assessed drug responses at one- and three-months post-PCI with VerifyNow and multiple electrode aggregometry assays. Results: At the one-month period, patients receiving standard-dose prasugrel or ticagrelor had lower platelet reactivity as determined by the three assays than those receiving the conventional dose of clopidogrel (VN: p = 0.000; MEA: p = 0.000; LTA: p = 0.000). At the 3-month point, platelet reactivity was lower in those receiving reduced-dose prasugrel or ticagrelor than the clopidogrel-treated patients (VN: p = 0.000; MEA: p = 0.012; LTA: p = 0.002). Prasugrel resulted in significantly lower platelet inhibition than ticagrelor as determined by VN and LTA (VN: p = 0.000; LTA: p = 0.003). At three months, there was a significant overall difference in OPR among the three groups when measured by VN (p < 0.001), but not when measured by MEA (p = 0.596). OPR in the reduced-dose prasugrel group was not significantly different to the clopidogrel group at three months (VN: p = 0.180; MEA: p = 0.711). OPR in the reduced-dose ticagrelor group was similar to clopidogrel as determined by MEA at three months, but was different when assessed by VN (VN: p = 0.000; MEA: p = 0.540). Compared to standard-dose, the reduced-dose prasugrel OPR rate was significantly increased (VN: p = 0.008; MEA: p = 0.020). Conclusions: OPR values for reduced-dose prasugrel and conventional-dose clopidogrel at three months were similar but higher than for reduced-dose ticagrelor as determined by VN, but no differences were noted by MEA. The MEA assay might have less sensitivity and consistency than the VN assay. Further studies are needed to explore this discrepancy.

Pharmacodynamics and Outcomes of a De-Escalation Strategy with Half-Dose Prasugrel or Ticagrelor in East Asians Patients with Acute Coronary Syndrome: Results from HOPE-TAILOR Trial.

East Asians treated with potent P2Y12 inhibitors (prasugrel or ticagrelor) generally experience more intense platelet inhibitory responses resulting in an increased risk of major bleeding. Whether a half-dose de-escalation strategy improves the net clinical benefit in Korean patients with acute coronary syndrome (ACS) remains uncertain. A total of 120 patients were pragmatically randomized to either prasugrel (n = 39, 60 mg loading dose (LD)/10 mg maintenance dose (MD)), ticagrelor (n = 40, 180 mg LD/90 mg MD), or clopidogrel (n = 41, 600 mg LD/75 mg MD) followed by a half-dose reduction at 1 month, or conventional dose 75 mg clopidogrel. The primary endpoint was the incidence of optimal platelet reactivity (OPR), defined as a P2Y12 reaction unit (PRU) value between 85 and 208 (by VerifyNow) at 3 months. Ticagrelor treatment achieved a significantly lower PRU compared with prasugrel and clopidogrel (31.0 ± 34.5 vs. 93.2 ± 57.1 vs. 153.1 ± 69.4), resulting in the lowest rate of OPR (12.5% vs. 48.7% vs. 63.4%). At 9 months, the minor bleeding was significantly higher with potent P2Y12 inhibitors than with clopidogrel (31.6% vs. 12.2%; HR, 2.93; 95% CI, 1.12-7.75). Only a few patients experienced ischemic complications. In Korean ACS patients, a de-escalation strategy with half-dose ticagrelor and prasugrel from standard dose increased the OPR rate significantly. Half-dose ticagrelor had a lower OPR rate and greater platelet inhibition compared with half-dose prasugrel as well as conventional-dose clopidogrel. Optimal dose reduction strategies for potent P2Y12 inhibitors require further investigation to balance safety and efficacy.