BACKGROUND AND OBJECTIVES:Computed tomography-derived fractional flow reserve (CT-FFR) uses standardized boundary conditions that cannot represent individual patient characteristics. We developed a calibration method to individualize boundary conditions using invasive fractional flow reserve (FFR) measurement. This study assessed the feasibility and impact on prediction of lesion-specific pressure drops (ΔFFR), post-percutaneous coronary intervention (PCI) FFR, and high-risk plaque (HRP) discrimination. METHODS:This retrospective multicenter study analyzed 79 patients with single left anterior descending lesions. Lumped parameter models were used to calibrate optimal boundary conditions by iteratively minimizing differences between invasive FFR and CT-FFR. HRP was assessed using an artificial intelligence-enabled analysis system, defined as low attenuation plaque, positive remodeling, or both. Discrimination performance was evaluated using ΔCT-FFR and CT-FFR gradient. RESULTS:In 79 patients (median age 65.5 years, 77.2% male), median angiographic percent diameter stenosis 60.0%, median invasive FFR was 0.83 and CT-FFR was 0.81 before calibration. Following calibration, FFR correlation improved from 0.590 to 0.997 (p<0.001). ΔFFR correlation increased from 0.490 to 0.823 (p<0.001). Post-PCI validation showed correlation improvement from 0.440 to 0.871 (p=0.002). HRP discrimination improved for ΔCT-FFR (area under the curve [AUC], 0.62 to 0.70; p=0.018) and CT-FFR gradient (AUC, 0.62 to 0.69; p=0.032). CONCLUSIONS:Individualized boundary condition calibration using invasive FFR enables accurate prediction of lesion-specific hemodynamics and post-intervention physiology, showing potential for enhanced procedural planning and risk stratification in patients undergoing coronary angiography.

Revascularization remains an important component of chronic coronary syndrome (CCS) management, particularly in patients with high-risk coronary anatomy, impaired left ventricular (LV) function, or persistent symptoms despite guideline-directed medical therapy. Evidence indicates that prognostic benefit is most pronounced in patients with left main disease, multivessel disease, proximal left anterior descending artery involvement, and severe LV systolic dysfunction. In other patients, revascularization primarily improves angina symptoms and quality of life. The choice between percutaneous coronary intervention (PCI) and coronary artery bypass grafting should be individualized according to coronary anatomy, clinical risk, comorbidities, and the likelihood of complete revascularization. Contemporary PCI increasingly incorporates coronary physiology and intravascular imaging to refine lesion selection and improve procedural outcomes. Long-term CCS management requires structured follow-up to detect disease progression, recurrent ischemia, revascularization failure, and cardiovascular complications. Routine surveillance testing is not recommended in asymptomatic patients after PCI. Instead, follow-up should be tailored to patient risk and clinical status. When complete revascularization fails, mechanisms such as stent thrombosis, in-stent restenosis, graft failure, and progression of untreated coronary disease should be identified; intravascular imaging has an important role in guiding repeat revascularization. Comprehensive CCS management should also address complications, including heart failure, ventricular arrhythmias, and secondary valvular disease, through a multidisciplinary, patient-centered approach.

Background Coronary artery bypass grafting (CABG) is the standard revascularization method for patients with diabetes mellitus (DM) and complex coronary artery disease. However, with significant advances in percutaneous coronary intervention (PCI), particularly the use of intravascular imaging (IVI), it is uncertain whether contemporary IVI-guided PCI can achieve clinical outcomes comparable with those of CABG. Objectives The aim of this study was to compare the clinical outcomes of IVI-guided PCI, angiography-guided PCI, and CABG in DM patients with left main or 3-vessel disease. Methods A total of 3,402 DM patients with left main or 3-vessel disease were included from individual patient-level data of the RENOVATE-COMPLEX-PCI (Randomized Controlled Trial of Intravascular Imaging Guidance Versus Angiography-Guidance on Clinical Outcomes After Complex Percutaneous Coronary Intervention) trial and the institutional registries of Samsung Medical Center (n = 6,962). The primary outcome, which was a composite of all-cause death, nonfatal myocardial infarction, or stroke at 3 years was compared among IVI-guided PCI, angiography-guided PCI, and CABG. Results In the DM population, the cumulative incidence of the primary outcome at 3 years was 20.1% for angiography-guided PCI, 11.4% for IVI-guided PCI, and 12.4% for CABG. PCI was associated with a significantly higher risk for primary outcome (17.0% vs 12.4%; HR: 1.91; 95% CI: 1.50-2.44; P < 0.001). However, the risk for the primary outcome was comparable between the IVI-guided PCI and CABG groups (11.4% vs 12.4%; HR: 0.88; 95% CI: 0.58-1.32; P = 0.525). A propensity score-matched analysis yielded similar results (HR: 0.85; 95% CI: 0.53-1.36; P = 0.507). Conclusions In this hypothesis-generating study, PCI was associated with significantly higher risk for all-cause death, nonfatal myocardial infarction, or stroke at 3 years than CABG in DM patients with left main or 3-vessel disease. However, IVI-guided PCI had comparable risk for clinical events compared with CABG in DM patients. Further randomized controlled trial is needed to confirm this finding. (Randomized Controlled Trial of Intravascular Imaging Guidance Versus Angiography-Guidance on Clinical Outcomes After Complex Percutaneous Coronary Intervention [RENOVATE-COMPLEX-PCI], NCT03381872; institutional cardiovascular catheterization database of Samsung Medical Center [Long-Term Outcomes and Prognostic Factors in Patient Undergoing CABG or PCI], NCT03870815; institutional CABG database of Samsung Medical Center, NCT03870815)

BACKGROUND:Whether strut thickness influences clinical outcomes after percutaneous coronary intervention (PCI) for bifurcation lesions remains debated. AIMS:To compare the safety and efficacy of ultrathin (< 70 µm) drug-eluting stents (DES) with thicker DES in coronary bifurcations. METHODS:We pooled patient-level data from the ULTRA and BIFURCAT registries. Stents were classified as thick (≥ 100 µm), thin (70-100 µm), or ultrathin (< 70 µm). The primary endpoint was target-lesion revascularization (TLR). Inverse probability of treatment weighting (IPTW) balanced baseline characteristics overall and within procedural subgroups (provisional vs. planned two-stent strategy). RESULTS:Among 6753 patients (median follow-up 800 days, IQR 400-900), 514 (8%) received thick, 5139 (76%) thin, and 1100 (16%) ultrathin stents. Crude TLR rates were 3.3%, 2.8%, and 1.1%, respectively (p = 0.001). After IPTW adjustment, ultrathin DES significantly reduced TLR compared with thick DES (HR 0.38, 95% CI = 0.16-0.89, p = 0.03) and with thin DES (HR 0.41, 95% CI 0.21-0.81, p = 0.01). In provisional-stenting cases, TLR risk did not differ across groups (HR: 0.53 vs. thick, p = 0.27; HR: 0.49 vs. thin, p = 0.07). Conversely, in planned two-stent procedures ultrathin DES resulted associated with TLR reduction versus thick DES (HR: 0.21, 95% CI 0.04-0.93, p = 0.04), with a nonsignificant trend for thin DES (HR: 0.31, p = 0.07). CONCLUSIONS:In contemporary bifurcation PCI, ultrathin DES are associated with a clinically and statistically significant reduction in repeat revascularization compared with thicker-strut platforms, a benefit driven predominantly by lesions treated with an upfront two-stent approach.

Despite statin therapy, achieving target low-density lipoprotein cholesterol (LDL-C) levels remain suboptimal in high-risk patients with atherosclerotic cardiovascular disease (ASCVD). This study evaluated efficacy and safety of early addition of ezetimibe (EZ) with atorvastatin (AS), prior to reaching the maximally tolerated dose of statin, in very high-risk patients. This phase 4 (NCT05761444), multicenter, randomized, open-label, active-controlled study enrolled patients (≥ 30 years) with very high-risk of ASCVD. Eligible patients had LDL-C ≥ 70 mg/dL with low/moderate intensity statin monotherapy or statin-naïve or not been on stable statin regimen prior to enrollment. Patients were randomized 1:1 to EZ10/AS40 mg combination therapy or AS40 mg statin alone for 12 weeks. Primary endpoint was percentage change in LDL-C from baseline to week 6. Patients (N = 137) received EZ/AS (n = 67) or AS (n = 70) once a day. The EZ/AS lipid-lowering effect was statistically greater than AS monotherapy at week 6 (LSMD: ˗21.2; P < 0.0001) and week 12 (LSMD: ˗16.0; P < 0.0001). At week 12, higher proportions of patients who received EZ/AS achieved target LDL-C < 55 mg/dL (55.0

BACKGROUND:Angiography-derived index of microcirculatory resistance (angio-IMR) is a reliable measure for assessing coronary microvascular function. However, the prognostic significance of changes in angio-IMR (Δangio-IMR) remains unclear. OBJECTIVES:The aim of this study was to assess the long-term prognostic utility of Δangio-IMR following percutaneous coronary intervention (PCI) in patients with intermediate coronary stenosis. METHODS:A total of 814 vessels with intermediate coronary stenosis that underwent PCI were enrolled from the FLAVOUR (Fractional Flow Reserve and Intravascular Ultrasound for Clinical Outcomes in Patients with Intermediate Stenosis) trial. The primary endpoint was target vessel failure (TVF) during long-term follow-up, defined as a composite of cardiac death, target vessel-related myocardial reinfarction, and target vessel revascularization. RESULTS:The median Δangio-IMR was 2.02 (Q1-Q3: 0.50-5.00). Using the 75th percentile (Δangio-IMR >5) as the cutoff, 203 vessels were assigned to the high Δangio-IMR group. Vessels with high Δangio-IMR demonstrated a significantly elevated risk for TVF compared with those with low Δangio-IMR (15.62% vs 9.47%; HR: 1.82; 95% CI: 1.15-2.88; P = 0.011). High Δangio-IMR independently predicted TVF (HR: 1.72; 95% CI: 1.04-2.83; P = 0.034). There was a notable interaction effect between Δangio-IMR and post-PCI angio-IMR (P = 0.028). A stratified analysis by post-PCI angio-IMR revealed that vessels with high Δangio-IMR showed a markedly increased TVF risk compared with vessels with low Δangio-IMR in those with post-PCI angio-IMR >25 (26.2% vs 11.9%; HR: 5.18; 95% CI: 1.28-20.94; P = 0.021), whereas no such association was observed in those with post-PCI angio-IMR ≤25 (12.6% vs 9.3%; HR: 1.33; 95% CI: 0.77-2.29; P = 0.305). CONCLUSIONS:An elevated Δangio-IMR correlates with a heightened risk of TVF in vessels with intermediate coronary stenosis underwent PCI. ΔAngio-IMR could be used as a valuable risk stratification indicator, particularly in patients with high post-PCI angio-IMR.

Isolated ostial side branch (SB) lesions (Medina 0.0.1) have traditionally been considered clinically minor because of their angiographically simple appearance and the limited myocardial territory supplied by most SBs. As a result, they have been underrepresented in clinical trials, creating an unmet need for evidence-based assessment and treatment strategies. This review summarizes emerging data demonstrating that Medina 0.0.1 lesions are not benign. Contemporary registries consistently report high rates of target lesion failure, comparable to true bifurcation lesions. These outcomes are driven by unique anatomical and physiological characteristics of the SB ostium, including disturbed flow, negative remodeling, elastic recoil, and frequent underestimation of disease severity by angiography. Intravascular imaging and physiological assessment often reveal occult plaque burden, hidden main vessel involvement, or clinically relevant ischemia. Clinically, these findings support an individualized approach, with a provisional strategy as the default and selective use of drug-coated balloons in carefully chosen cases. This article redefines Medina 0.0.1 lesions as a distinct high-risk entity and highlights the need for dedicated prospective studies.

BACKGROUND:Although physiological assessment has been used in decision-making for revascularization, its role in predicting the future risk of acute coronary syndrome (ACS) remains underexplored. OBJECTIVES:This study aims to investigate the independent and combined prognostic significance of hemodynamic disease severity and distribution in identifying ACS culprit vessels, in conjunction with lumen and plaque characteristics. METHODS:The EMERALD-II study is an international, multicenter, internal case-control study enrolling 351 patients with ACS who underwent coronary computed tomography angiography (CTA) 1 month to 3 years before the event. Culprit and nonculprit vessels were identified by matching invasive coronary angiography with coronary CTA findings. High-risk plaque (HRP) characteristics, including minimum lumen area <4 mm2, plaque burden ≥70%, low-attenuation plaque, positive remodeling, spotty calcification, and napkin-ring sign, were assessed by a core laboratory, with HRP defined as ≥3 HRP characteristics. From coronary CTA, the authors derived both the hemodynamic severity of the disease (fractional flow reserve derived from computed tomography [FFRCT]) and its spatial distribution (diffuse vs focal), as assessed by the pullback pressure gradient derived from coronary CTA (PPGCT). Vessels were categorized into 4 hemodynamic disease patterns: nonischemic (FFRCT >0.80), hemodynamic diffuse (FFRCT ≤0.80 and PPGCT ≤0.50), mixed (FFRCT ≤0.80 and 0.50 < PPGCT ≤0.60), and focal disease (FFRCT ≤0.80 and PPGCT >0.60). RESULTS:Among 873 vessels, the mean FFRCT was 0.74 ± 0.17 and the mean PPGCT was 0.54 ± 0.14. Both lower FFRCT and higher PPGCT were independently associated with higher ACS risk (OR per 0.1 increase in FFRCT: 0.71 [95% CI: 0.65-0.77]; P < 0.001; OR per 0.1 increase in PPG: 1.22 [95% CI: 1.09-1.37]; P < 0.001). Among the 4 subgroups of hemodynamic disease pattern, hemodynamic focal disease showed the highest risk of ACS (relative risk [RR]: 2.02 [95% CI: 1.74-2.36]; P < 0.001), myocardial infarction (RR: 1.75 [95% CI: 1.43-2.14]; P < 0.001), and unstable angina (RR: 2.54 [95% CI: 2.00-3.22]; P < 0.001). It remained a predictor for ACS in nonobstructive lesions (OR: 3.56 [95% CI: 1.43-8.84]), obstructive lesions (OR: 3.16 [95% CI: 1.96-5.07]), non-HRP (OR: 6.69 [95% CI: 3.59-12.5]), and HRP (OR: 2.98 [95% CI: 1.83-4.87]). Although the maximal lesion-level ΔFFRCT (differences in FFRCT across the lesion) demonstrated superior model performance compared with models incorporating FFRCT and PPGCT, higher PPGCT was additionally associated with increased ACS risk, particularly among vessels with maximal ΔFFRCT ≥0.10. CONCLUSIONS:Hemodynamic disease distribution, as measured by PPGCT, complements FFRCT in predicting ACS risk. The integration of hemodynamic disease patterns provides additional prognostic value beyond lumen and plaque characteristics, with hemodynamic focal disease emerging as an independent predictor and a potential therapeutic target for ACS prevention. (Exploring the Mechanism of Plaque Rupture in Acute Coronary Syndrome Using Coronary CT Angiography and Computational Fluid Dynamics II [EMERALD II]; NCT03591328).

BACKGROUND:Advancing age is associated with epicardial atherosclerosis and coronary microvascular dysfunction (CMD), complicating reliable assessment of CMD using coronary flow reserve (CFR). Whether prevalence of functional and structural CMD varies with age remains unclear. OBJECTIVES:The authors sought to evaluate the prevalence of CMD endotypes by age strata and compare CFR with microvascular resistance reserve (MRR) for diagnosis and stratification. METHODS:Data from 1,704 patients (2,283 lesions) with stable angina in the ILIAS Registry (Inclusive Invasive Physiological Assessment in Angina Syndromes Registry) were analyzed, including obstructive (fractional flow reserve ≤0.80) and nonobstructive (fractional flow reserve >0.80) lesions. CMD was classified as no CMD (MRR ≥3.0), functional CMD (MRR <3.0, normal resistance), or structural CMD (MRR <3.0, abnormal resistance). CMD classification was repeated using CFR (<2.5 abnormal). Patients were stratified per age decade: <50, 50-59, 60-69, 70-79, and ≥80 years. RESULTS:CMD prevalence by MRR was 48.2%, and increased across age strata (37.2% to 78.0%; P < 0.001), driven by structural CMD (10.9% to 40.0%; P < 0.001), while functional CMD prevalence remained unchanged (26.3% to 38.0%; P = 0.220). Age independently predicted functional (OR/y: 1.02; P < 0.001) and structural CMD (OR/y: 1.05; P < 0.001). In obstructive lesions, age predicted structural CMD (OR/y: 1.03; P = 0.0055); in nonobstructive lesions, age predicted functional (OR/y: 1.02; P = 0.0032) and structural CMD (OR/y: 1.06; P < 0.001). Overall CMD prevalence by CFR exceeded MRR across groups (53.3% vs 48.2%; P < 0.001), irrespective of epicardial disease. CONCLUSIONS:Structural CMD increases with age regardless of obstructive CAD, while functional CMD prevalence increases only in nonobstructive CAD. CFR may overestimate CMD in epicardial disease, whereas MRR provides a more consistent assessment regardless of obstructive CAD, underscoring the need for prospective studies on their clinical relevance.

BACKGROUND:The role of long-term beta-blocker therapy after a myocardial infarction in patients without left ventricular systolic dysfunction or heart failure is unclear in the era of contemporary coronary-artery reperfusion and secondary prevention interventions. METHODS:We conducted an open-label, randomized, noninferiority trial at 25 centers in South Korea. Patients whose condition remained stable after a myocardial infarction, who had a left ventricular ejection fraction of at least 40% and no heart failure, and who had received beta-blocker therapy for at least 1 year after the myocardial infarction were randomly assigned in a 1:1 ratio to discontinue or to continue beta-blocker therapy. The primary end point was a composite of death from any cause, recurrent myocardial infarction, or hospitalization for heart failure. The prespecified noninferiority margin was an upper limit of the 95% confidence interval for the hazard ratio of 1.4. RESULTS:A total of 2540 patients underwent randomization; 1246 were assigned to beta-blocker discontinuation and 1294 to beta-blocker continuation. The mean age of the patients was 63.2 years, and 12.8% were women. At a median follow-up of 3.1 years (interquartile range, 2.5 to 3.5), a primary end-point event had occurred in 58 patients (4-year Kaplan-Meier estimate, 7.2%) in the discontinuation group and in 74 patients (4-year Kaplan-Meier estimate, 9.0%) in the continuation group (hazard ratio, 0.80; 95% confidence interval, 0.57 to 1.13; P = 0.001 for noninferiority). The incidence of serious adverse events was similar in the two groups. CONCLUSIONS:Among patients who received beta-blocker therapy beyond the first year after a myocardial infarction, discontinuation of beta-blocker therapy was noninferior to continuation with respect to a composite of death from any cause, recurrent myocardial infarction, or hospitalization for heart failure. (Funded by Patient-Centered Clinical Research Coordinating Center in the Ministry of Health and Welfare, South Korea; SMART-DECISION ClinicalTrials.gov number, NCT04769362.).

Coronary artery disease is one of the leading causes of death worldwide and represents a major health burden in Korea. Chronic coronary syndrome (CCS) encompasses the long-term and heterogeneous clinical manifestations of ischemic heart disease, ranging from obstructive epicardial disease to non-obstructive and microvascular disease. This pathophysiological heterogeneity necessitates individualized diagnostic and therapeutic strategies to prevent progression from CCS to acute coronary syndrome. Since the publication of recent CCS guidelines, new evidence has emerged regarding optimal diagnostic strategies, physiological and intravascular imaging-based assessments, and medical therapy. In addition, contemporary CCS management increasingly emphasizes multidisciplinary integration, including cardiovascular prevention, non-invasive imaging-guided decision-making, and patient-centered revascularization strategies. However, the implementation of these principles in real-world Korean clinical practice remains unclear, highlighting the need for localized, evidence-based guidance for Korean patients with CCS. This expert consensus provides a comprehensive, stepwise framework for the diagnosis, treatment, and long-term management of CCS by integrating the latest international evidence with Korean clinical data and practice patterns.

BACKGROUND:While angiography-derived fractional flow reserve (AngioFFR)- and intravascular ultrasound (IVUS)-guided percutaneous coronary intervention (PCI) yield similar outcomes, with AngioFFR associated with lower PCI rates, the relative clinical effectiveness of AngioFFR versus IVUS-guided PCI according to angiographic lesion characteristics remains unclear. METHODS:This post hoc analysis of the FLAVOUR II trial (Comparison of Angiography-Derived Fractional Flow Reserve- and Intravascular Ultrasound-Guided Intervention Strategy for Clinical Outcomes in Patients with Coronary Artery Disease) included patients with ≥50% stenosis randomized to AngioFFR- or IVUS-guided PCI. A composite lesion risk score was derived using a marginal Cox model-based linear predictor incorporating % diameter stenosis, lesion length, true bifurcation, ostial lesion, and heavy calcification. The primary end point was target vessel failure (TVF: cardiac death, target vessel myocardial infarction, and target vessel revascularization). RESULTS:Among 1726 patients, 884 (51.2%) underwent AngioFFR-guided PCI and 842 (48.8%) underwent IVUS-guided PCI. During a median 12-month follow-up, TVF occurred in 2.4% of AngioFFR-treated vessels and 1.9% of IVUS-treated vessels (P=0.50). TVF risk increased progressively with a higher composite lesion risk score (adjusted hazard ratio, 2.76 [95% CI, 1.35-5.65]). This association was more pronounced in the AngioFFR group (adjusted hazard ratio, 3.93 [95% CI, 1.79-8.63]) than in the IVUS group (adjusted hazard ratio, 1.62 [95% CI, 0.42-6.22]). Compared with IVUS guidance, AngioFFR-guided vessels with high-risk lesions (score >0.32) had a higher TVF rate (5.1% versus 1.9%; P=0.010), whereas outcomes were comparable in those with low-risk lesions (1.5% versus 1.9%; P=0.531). AngioFFR guidance was associated with lower target vessel PCI rates in low-risk lesions (60.1% versus 76.5%; P<0.001), whereas PCI rates were uniformly high and similar between groups in high-risk lesions (96.4% versus 97.4%; P=0.675). CONCLUSIONS:A higher composite lesion risk score was associated with increased PCI rates and TVF risk after AngioFFR- or IVUS-guided treatment. AngioFFR guidance was associated with lower PCI rates in low-risk lesions, whereas IVUS guidance may yield more favorable outcomes in high-risk lesions. REGISTRATION:URL: https://www.clinicaltrials.gov; Unique identifier: NCT04397211.

BACKGROUND:Medina 0.0.1 bifurcation lesions show high target lesion failure (TLF) after drug-eluting stent (DES) percutaneous coronary intervention (PCI), highlighting an unmet need for alternative treatment strategies. METHODS AND RESULTS:We analyzed 101 patients with Medina 0.0.1 lesions treated with DCB-based PCI from the REAL-DCB registry and 95 DES-treated controls from the COBIS III registry. Primary endpoint was 2-year target lesion failure (TLF): cardiac death, target-vessel myocardial infarction, and clinically-driven target-lesion revascularization (TLR). Inverse probability of treatment weighting (IPTW) was applied to account for inter-group imbalance. DCB group, albeit slightly younger, had more complex risk profile compared to DES group. DCB-based PCI enabled one-device strategy in 96.0% of cases, requiring significantly fewer devices and shorter device lengths than DES-only PCI, in which 52.6% of lesions were treated with a two-stent strategy. Two-year TLF was lower with DCB than with DES (2.2% vs. 12.1%), and this difference remained significant after IPTW adjustment (IPTW-HR: 0.10; 95% CI: 0.02-0.46; P = 0.003), mainly due to lower TLR (IPTW-HR: 0.13; 95% CI: 0.03-0.59; P = 0.009). Target-vessel revascularization was also less frequent with DCB (IPTW-HR: 0.10; 95% CI: 0.02-0.48; P = 0.004). No target-lesion thrombosis occurred in DCB group, whereas one stent thrombosis was reported in DES group. Between-group difference was driven predominantly by TLR, whereas hard ischemic events were infrequent in both groups. CONCLUSIONS:In Medina 0.0.1 lesions, DCB-based PCI strategy was associated with lower TLF than DES-only PCI while enabling a simplified device-sparing approach. Given the observational design and limited event count, these findings should be considered hypothesis-generating.

BACKGROUND:We aimed to investigate the challenges Korean physicians face in assisting their high-risk atherosclerotic cardiovascular disease (ASCVD) patients in achieving guideline-recommended low-density lipoprotein cholesterol (LDL-C) levels. METHODS:We performed a prospective, implementation science study including 704 patients at very high risk of ASCVD with baseline LDL-C ≥ 70 mg/dL (1.8 mmol/L) while receiving maximally tolerated statins and/or ezetimibe for secondary prevention between 2020 and 2022. The primary evaluation criteria were the proportions of participants achieving LDL-C < 70 mg/dL at each visit. The secondary evaluation criteria included the proportions of participants in diverse situations associated with guideline adoption. RESULTS:The proportions of participants achieving LDL-C < 70 mg/dL at visits 2 (week 6-16) and 3 (week 18-30) were 56.3% and 58.7%, respectively. Among 307 patients on maximally tolerated statins and 397 patients on maximally tolerated statins and ezetimibe at baseline, physicians did not have an intention to intensify the lipid-lowering treatment regimen of 171 patients (55.7%) and 299 patients (75.3%) at visit 1, respectively. In both groups, physician disagreement with the guidelines was the major reason for not adopting the recommended therapy (70.8% and 46.2%, respectively), followed by patient refusal for reasons other than the cost, medical limitations such as comorbidities, and drug costs. CONCLUSION:This implementation science study for secondary prevention involving very high-risk ASCVD patients revealed that the proportion of patients achieving LDL-C < 70 mg/dL via lipid-lowering therapy was less than 60%. The main reason for not adopting the recommended LDL-C-lowering therapy was physician disagreement with the guidelines. TRIAL REGISTRATION:Clinical Research Information Service Identifier: KCT0005488.

Background Angiography‐based fractional flow reserve (FFR) techniques offer wire‐free alternatives but often require manual segmentation and 3‐dimensional reconstruction. Although an artificial intelligence‐driven approach automates these steps, validation remains limited. This study investigated the diagnostic performance of an artificial intelligence‐driven angiography‐based FFR (medipixel FFR [MPFFR]), compared with quantitative flow ratio (QFR) in predicting functionally significant coronary artery stenosis defined by FFR ≤0.80. Methods A total of 599 vessels from 452 patients who underwent clinically indicated FFR measurement were prospectively enrolled from 5 university hospitals in Korea. MPFFR used automated processes in frame selection, artificial intelligence contour detection, corresponding points matching, 3‐dimensional reconstruction, and analytical hemodynamic modeling. The primary end point was diagnostic accuracy for detecting FFR ≤0.80. Secondary end points were target vessel failure (composite of cardiac death, target‐vessel myocardial infarction, and target‐vessel revascularization) at 2 years. Results Mean analysis time of MPFFR was 12.5±1.7 seconds and manual correction was needed in 32 vessels (5.3%). MPFFR showed similar diagnostic performance with QFR (correlation with FFR; MPFFR versus QFR: R=0.885 versus R=0.860, P for comparison=0.011; area under the curve to predict FFR ≤0.80; 0.949 versus 0.953, P for comparison=0.631). At a median follow‐up of 2 years (interquartile range, 1.6–2.6 years), patients with MPFFR ≤0.80 had higher risk of target vessel failure than those with MPFFR >0.80 (4.5% versus 0.8%; adjusted hazard ratio, 5.94 [95% CI, 1.27–27.91]; P =0.024). C‐index to predict target vessel failure was comparable between MPFFR and QFR (0.770 versus 0.753, P for comparison=0.469). Conclusions In this multicenter registry, an artificial intelligence‐driven angiography‐based FFR demonstrated comparable diagnostic accuracy with QFR in identifying functionally significant stenosis, and similar prognostic ability with QFR in terms of target vessel failure at 2 years. Registration Multicenter QFR Registry; Unique Identifier: NCT03791788.

This focused update from the Korean Society of Myocardial Infarction provides consensus recommendations for revascularization in acute coronary syndrome (ACS), integrating major trial evidence since 2021 with Korean real-world practice. A multidisciplinary writing committee reviewed randomized trials, meta-analyses, and recent guidelines, and achieved consensus document. Key recommendations are as follows: 1) Cardiogenic shock: prioritize culprit-first revascularization with early reassessment; apply mechanical circulatory support selectively, guided by shock phenotype and escalation criteria rather than routine use; 2) Non-ST segment elevation ACS: use risk-stratified invasive timing with clear triggers for urgent versus early angiography; 3) Access and imaging: adopt radial-first access and broaden intravascular imaging for complex anatomy, ambiguous culprit lesions, and optimization of stent expansion; 4) Non-culprit lesion: favor complete revascularization in ST-segment elevation myocardial infarction (MI) with multivessel disease; select immediate versus staged procedures based on hemodynamics, ischemic burden, renal function, and contrast load. (5) Special scenarios: implement mechanism-based pathways for MI with non-obstructive coronary arteries and spontaneous coronary artery dissection (SCAD), incorporating intracoronary imaging, functional testing, vasospasm provocation, and cardiac magnetic resonance imaging; prefer conservative treatment for SCAD unless ongoing ischemia persists. The document provides concise "do" statements, and a summary of changes from 2021 to facilitate bedside adoption. These recommendations aim to standardize high-value, patient-centered ACS care in Korea, reduce practice variability, and improve outcomes while acknowledging areas requiring further evidence.

BACKGROUND:Post-percutaneous coronary intervention (PCI) fractional flow reserve (FFR) and relative FFR increase after PCI are determined by the interaction of baseline disease pattern, adequacy of PCI, and residual disease burden in a target vessel. However, the prognostic impact of relative FFR increase after PCI remains uncertain. OBJECTIVES:The aim of this study was to evaluate the prognostic relevance of relative FFR increase in addition to post-PCI FFR in patients undergoing PCI. METHODS:From the International Post PCI FFR Extended Registry, 1,497 patients with pre-PCI FFR ≤0.80 were analyzed. The relative FFR increase was expressed as a percentage and calculated as percentage FFR increase (ΔFFR%) with PCI ([post-PCI FFR - pre-PCI FFR]/pre-PCI FFR × 100). The primary endpoint was 5-year target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction, or target vessel revascularization (TVR). TVR was further specified as target lesion revascularization (TLR) or non-TLR TVR. RESULTS:Maximally selected log-rank statistics identified 15.0% and 0.80 as the cutoffs to discriminate the occurrence of TVF for ΔFFR% and post-PCI FFR, respectively. Failure to meet either cutoff was associated with increased risk for TVF (ΔFFR%: 10.9% [122 of 1,148] vs 17.6% [59 of 349] [adjusted HR: 1.72; 95% CI: 1.23-2.42; P = 0.002]; post-PCI FFR: 10.9% [136 of 1,279] vs 21.3% [45 of 218] [adjusted HR: 2.08; 95% CI: 1.47-2.94; P < 0.001]). Patients with post-PCI FFR ≤0.80 had increased TVF compared with those with post-PCI FFR >0.80, regardless of sufficient (≥15.0%) or insufficient (<15.0%) relative FFR increase. The higher risk for TVF in patients with post-PCI FFR ≤ 0.80 compared with those with post-PCI FFR >0.80 was driven primarily by non-TLR TVR (2.2% vs 6.0%; P = 0.015) in the sufficient ΔFFR% group (≥15.0%), whereas it was attributable mainly to TLR (6.6% vs 17.0%; P = 0.008) in the insufficient ΔFFR% group (<15.0%). CONCLUSIONS:Relative FFR increase after PCI provides prognostic implications comparable with post-PCI FFR. Among patients with insufficient relative FFR increase, post-PCI FFR ≤0.80 was associated with an increased risk for restenosis within stented segments, whereas among those with sufficient relative FFR increase, post-PCI FFR ≤0.80 was associated with risk driven by disease progression in nonstented segments.