Fully automated quantitative coronary angiography versus optical coherence tomography guidance for coronary stent implantation (FLASH): Study protocol for a randomized controlled noninferiority trial.

BACKGROUND: Artificial intelligence-based quantitative coronary angiography (AI-QCA) has been developed to provide a more objective and reproducible data about the severity of coronary artery stenosis and the dimensions of the vessel for intervention in real-time, overcoming the limitations of significant inter- and intraobserver variability, and time-consuming nature of on-site QCA, without requiring extra time and effort. Compared with the subjective nature of visually estimated conventional CAG guidance, AI-QCA guidance provides a more practical and standardized angiography-based approach. Although the advantage of intravascular imaging-guided PCI is increasingly recognized, their broader adoption is limited by clinical and economic barriers in many catheterization laboratories. METHODS: The FLASH (fully automated quantitative coronary angiography versus optical coherence tomography guidance for coronary stent implantation) trial is a randomized, investigator-initiated, multicenter, open-label, noninferiority trial comparing the AI-QCA-assisted PCI strategy with optical coherence tomography-guided PCI strategy in patients with significant coronary artery disease. All operators will utilize a novel, standardized AI-QCA software and PCI protocol in the AI-QCA-assisted group. A total of 400 patients will be randomized to either group at a 1:1 ratio. The primary endpoint is the minimal stent area (mm2), determined by the final OCT run after completion of PCI. Clinical follow-up and cost-effectiveness evaluations are planned at 1 month and 6 months for all patients enrolled in the study. RESULTS: Enrollment of a total of 400 patients from the 13 participating centers in South Korea will be completed in February 2024. Follow-up of the last enrolled patients will be completed in August 2024, and primary results will be available by late 2024. CONCLUSION: The FLASH is the first clinical trial to evaluate the feasibility of AI-QCA-assisted PCI, and will provide the clinical evidence on AI-QCA assistance in the field of coronary intervention. CLINICAL TRIAL REGISTRATION: URL: https://www. CLINICALTRIALS: gov. Unique identifier: NCT05388357.

Assessment of optimal renin-angiotensin-system inhibition strategy in Asian patients with STEMI after primary myocardial revascularization.

BACKGROUND: For the Asian patients with STEMI undergoing PCI, ACEIs are known to have a better outcome than ARBs. However, there is limited evidence to suggest so. METHODS: Among the STEMI registry consist of 1142 Korean patients, we compared the MACE, the composite of myocardial infarction, stoke, death, admission for heart failure, and target vessel revascularization, between the ACEI and ARB groups (Set 1). Further, we defined adequate medication as the administration of a dose equal to or higher than the initiation dose of ACEI according to the heart failure guideline recommendation with a mandatory addition of beta-blockers, and compared the outcomes between the inadequate and adequate medication groups (Set 2). Propensity score matching was used to eliminate difference. RESULTS: In the Set 1 comparison, patients in the ACEI group had a better outcome than those in the ARB group for both whole and matched populations (whole and matched population: Cox regression hazard ratio [HR], 0.645 and 0.535; 95% confidence interval [CI], 0.440-0.944 and 0.296-0.967; p = 0.024 and p = 0.039, respectively). In the Set 2 comparison for the whole population, patients in the inadequate medication group had more MACE than those in the adequate medication group (HR, 0.673; 95% CI, 0.459-0.985; p = 0.042). However, no difference was observed after propensity score matching (HR, 1.023; 95% CI, 0.654-1.602; p = 0.919). CONCLUSION: ACEIs might be a better choice than ARBs after primary revascularization. However, this study's findings suggest that early ACEI dose escalation combined with beta-blocker use may not improve prognosis.

Pharmacodynamic Profile and Prevalence of Bleeding Episode in East Asian Patients with Acute Coronary Syndromes Treated with Prasugrel Standard-Dose versus De-escalation Strategy: A Randomized A-MATCH Trial.

Compared with Caucasian patients, East Asian patients have the unique risk-benefit trade-off and different responsiveness to antithrombotic regimens. The aim of this study was to compare pharmacodynamic profile in East Asian patients with acute coronary syndromes (ACSs) treated with prasugrel standard-dose versus a de-escalation strategy. Before discharge, ACS patients with age <75 years or weight ≥60 kg (n = 255) were randomly assigned to the standard-dose (10-mg group) or de-escalation strategy (5-mg group or platelet function test [PFT]-guided group). After 1 month, VerifyNow P2Y12 assay-based platelet reactivity (P2Y12 reaction unit [PRU]) and bleeding episodes were evaluated. Primary endpoint was the percentage of patients with the therapeutic window (85 ≤ PRU ≤ 208). The 250 patients completed 1-month treatment. The percentage of patients within the therapeutic window was significantly lower in the 10-mg group (n = 85) compared with the 5-mg (n = 83) and PFT-guided groups (n = 82) (35.3 vs. 67.5 vs. 65.9%) (odds ratio [OR]: 3.80 and 3.54; 95% confidence interval [CI]: 2.01-7.21 and 1.87-6.69, respectively). Compared with the 10-mg group, the bleeding rate was tended to be lower with de-escalation strategies (35.3 vs. 24.1% vs. 23.2%) (hazard ratio [HR]: 0.58 and 0.55; 95% CI: 0.30-1.14 and 0.28-1.09, respectively). "PRU < 127" was the optimal cut-off for predicting 1-month bleeding events (area under the curve: 0.616; 95% CI: 0.543-0.689; p = 0.005), which criteria was significantly associated with early discontinuation of prasugrel treatment (HR: 2.00; 95% CI: 1.28-3.03; p = 0.001). In conclusion, compared with the standard-dose prasugrel, the prasugrel de-escalation strategy in East Asian patients presented with ACS showed a higher chance within the therapeutic window and a lower tendency toward bleeding episodes. REGISTRATION: URL: https://clinicaltrials.gov. Unique identifier:NCT01951001.

Discordance Between Fractional Flow Reserve and Coronary Flow Reserve: Insights From Intracoronary Imaging and Physiological Assessment.

OBJECTIVES: The aim of this study was to investigate the epicardial and microvascular substrates associated with discordances between fractional flow reserve (FFR) and coronary flow reserve (CFR) values. BACKGROUND: Discordances between FFR and CFR remain poorly characterized. METHODS: FFR, hyperemic stenosis resistance (HSR), and intravascular ultrasound were performed as indexes of epicardial function and CFR and hyperemic microvascular resistance (HMR) as measures of microvascular function in 94 patients with moderate coronary stenosis. Maximal plaque burden (PBmax), HSR, and HMR were calculated in 4 quadrants based on values of FFR ≤0.80 and CFR ≤2.0 as follows: concordant normal (preserved FFR and CFR), concordant abnormal (low FFR and CFR), discordant low FFR and preserved CFR, and discordant preserved FFR and low CFR. RESULTS: Sixty-four patients (68%) had concordant FFR and CFR findings, and 30 patients (32%) had discordant FFR and CFR. Compared with patients with preserved FFR and CFR, those with low FFR and CFR had higher PBmax (p = 0.003), higher HSR (p < 0.001), and similar HMR. Among patients with preserved FFR, those with reduced CFR had similar PBmax and HSR but a trend toward higher HMR (p = 0.058) compared with patients with preserved CFR. Among patients with reduced FFR, those with preserved CFR had lower PBmax (p = 0.004), a trend toward lower HSR (p = 0.065), and lower HMR (p = 0.03) compared with patients with reduced CFR. Furthermore, compared with patients with preserved FFR and low CFR, those with low FFR and preserved CFR had higher HSR (p = 0.022) but lower HMR (p = 0.003). CONCLUSIONS: In patients with moderate coronary stenosis, preserved FFR and low CFR is associated with increased microvascular resistance, while low FFR and preserved CFR has modest epicardial stenosis and preserved microvascular function.