BACKGROUND AND AIMS:Calcified coronary plaques frequently harbor lipid-rich components, yet identifying residual lipid burden within calcification remains challenging. This study aimed to evaluate the ability of optical coherence tomography (OCT) to identify lipidic calcification, utilizing near-infrared spectroscopy intravascular ultrasound (NIRS-IVUS) as the reference standard. METHODS:We retrospectively analyzed patients undergoing PCI for de novo calcified lesions (IVUS arc ≥90°) assessed by both NIRS-IVUS and OCT. Lipidic calcification was defined as a lesion with a maximum lipid core burden index in 4 mm (maxLCBI4mm) ≥400, reflecting lesion-level lipid burden within a calcified plaque segment, rather than lipid strictly co-localized with calcium. On OCT, the "attenuated calcium index" was calculated as the mean angle of calcification exhibiting an invisible trailing edge across the 20-mm lesion segment. We compared clinical and imaging characteristics between vessels with and without lipidic calcification. RESULTS:Among 102 patients, 38 lesions (37.3%) exhibited lipidic calcification. While clinical demographics were comparable between groups, OCT analysis revealed significantly greater lipid length, attenuated calcium index, and prevalence of cholesterol crystals in the lipidic calcification group. Multivariable analysis identified the attenuated calcium index (OR 1.03; 95% CI 1.01-1.05) and cholesterol crystals (OR 7.50; 95% CI 2.68-20.9) as independent predictors of lipidic calcification. Furthermore, among calcified nodules, eruptive nodules demonstrated a significantly higher maxLCBI4mm than non-eruptive ones (401 vs. 208; p = 0.035). CONCLUSIONS:The OCT-derived attenuated calcium index and cholesterol crystals are distinct markers associated with lipidic calcification. Additionally, eruptive calcified nodules appear to harbor a greater lipid burden. OCT facilitates the identification of lipid-rich phenotypes even within complex calcified lesions.

BACKGROUND:Optical coherence tomography (OCT) can identify the underlying causes of acute coronary syndrome (ACS), including plaque rupture (PR), plaque erosion (PE), and eruptive calcified nodule (CN), which may have prognostic implications. However, the duration and extent of their impacts remain unclear. METHODS:The multicentre prospective TACTICS registry enrolled patients with ACS undergoing OCT-guided percutaneous coronary intervention within 24 hours of symptom onset. Two-year clinical outcomes were assessed in 617 patients with OCT-diagnosed PR, PE, or CN (n = 411, 178, and 28, respectively). Major adverse cardiac events (MACE), a composite of cardiovascular death, myocardial infarction, heart failure, or ischemia-driven revascularisation, were independently adjudicated. RESULTS:During a median follow-up of 736 days, MACE occurred most frequently in CN (46.4%), primarily driven by cardiovascular death and ischemia-driven revascularisation, followed by PR (13.9%) and PE (8.4%) (log-rank P < 0.001). Landmark Cox analysis demonstrated that within 180 days, CN and PR carried substantially higher MACE risk than PE (CN: HR 9.77, 95% CI 2.96-35.29 [P < 0.001]; PR: HR 3.19, 95% CI 1.32-9.94 [P = 0.008]). Beyond 180 days, CN continued to exhibit significantly elevated risk (HR 6.30, 95% CI 2.39-15.60; P < 0.001), whereas PR did not differ from PE (HR 1.04, 95% CI 0.53-2.17; P = 0.915). CONCLUSIONS:Compared with PE, CN was associated with persistently adverse outcomes, whereas PR conferred elevated risk primarily in the early phase. OCT-defined underlying causes of ACS may help to identify high risk phenotypes and provide prognostic insight into temporal risk profiles. CLINICAL TRIAL REGISTRATION:UMIN000039050.

Percutaneous transluminal septal myocardial ablation (PTSMA) is an established treatment for hypertrophic obstructive cardiomyopathy (HOCM), but its application in patients with situs inversus totalis (SIT) is complicated by mirror-image anatomy. We describe two successful PTSMA procedures in women, aged 82 and 69 years, with HOCM and coexisting SIT. The second patient had additional complexities, including Kartagener syndrome and chronic steroid therapy for rheumatoid arthritis. Both patients presented with severe, drug-refractory symptoms and significant left ventricular outflow tract (LVOT) pressure gradients. Guided by meticulous pre-procedural planning and multi-modality imaging, PTSMA was successfully performed, leading to a substantial reduction in LVOT gradients and marked symptomatic relief in both patients. The procedures were well-tolerated without major complications, demonstrating the feasibility of PTSMA despite advanced age, complex comorbidities, and profound anatomical variations. Our experience suggests that PTSMA is a viable, safe, and effective therapeutic option for HOCM in the rare and complex setting of SIT. Learning objective 1.To recognize that percutaneous transluminal septal myocardial ablation (PTSMA) can be a feasible, safe, and effective septal reduction therapy for patients with hypertrophic obstructive cardiomyopathy and coexisting situs inversus totalis, leading to significant hemodynamic and clinical improvement.2.To understand that advanced age and comorbidities, such as chronic low-dose steroid use, are not absolute contraindications to PTSMA.3.To appreciate the critical importance of meticulous pre-procedural planning and multi-modality intraprocedural imaging to navigate mirror-image anatomy and ensure procedural success.

The clinical course of acute myocarditis varies widely, making accurate prognostication difficult. Nutritional assessment aids risk stratification in various cardiovascular diseases; however, its role in myocarditis remains unclear. This study examined the association between Geriatric Nutritional Risk Index (GNRI)-defined nutritional risk, and prognosis in acute myocarditis. We analyzed admission data on patients with acute myocarditis hospitalized via emergency medical services from the multicenter Tokyo CCU Network Database between January 2017 and December 2022. Nutritional risk was assessed using the GNRI (≥ 98 normal nutrition; 92 to < 98 low; 82 to < 92 moderate; ≤82 severe). The primary outcome was in-hospital death, and secondary outcomes included hospital length of stay (LOS) and cardiovascular care unit LOS. Multivariable Cox regression assessed the association between GNRI-defined nutritional risk and outcomes, adjusting for patient characteristics. Among 402 patients, the median age was 43 years [27–66], and 24.9

BACKGROUND: Angina with nonobstructive coronary arteries (ANOCA) is frequently driven by coronary vasospasm and coronary microvascular dysfunction (CMD). Despite recommendations for comprehensive invasive testing to phenotype ANOCA, prospective data on the prevalence and interplay of these endotypes remain limited. We aimed to investigate the prevalence, clinical correlations, and overlap of epicardial vasospasm, microvascular spasm, and CMD, defined by a coronary flow reserve <2.0. METHODS: We analyzed the data from a prospective, multicenter nationwide registry of the J-CMD (Japanese Association of Coronary Microvascular Dysfunction; UMIN000047609). Patients with ANOCA underwent standardized intracoronary functional testing, including acetylcholine-based spasm provocation and coronary flow reserve assessment. The distribution of the endotypes (epicardial vasospasm, microvascular spasm, isolated CMD, and CMD with spasm) was investigated according to sex and age tertiles. RESULTS: Of 947 patients (55.6% women), epicardial vasospasm was the most common diagnosis (44.2%), followed by micro-vascular spasm (16.5%), CMD with spasm (8.7%), and isolated CMD (5.0%). Substantial overlap was evident; concurrent CMD and any vasospasm were more frequent in women than in men (10.8% versus 6.0%, P=0.011). While microvascular spasm was more prevalent in women, CMD was associated with older age, female sex, hypertension, and diabetes. Intriguingly, the prevalence of these endotypes varied with age in women, a pattern not observed in men. CONCLUSIONS: Among patients with ANOCA, coronary vasospasm and CMD were prevalent and frequently coexisted, demonstrating distinct sex-and age-related patterns. These findings offer novel insights into the heterogeneous pathophysiology of ANOCA and reinforce the importance of comprehensive invasive assessment in establishing a precise diagnosis and guiding targeted therapy.

Background:Microvascular spasm (MVS), a phenotype of microvascular dysfunction in patients with angina with non-obstructive coronary arteries (ANOCA), involves transient microvascular constriction. The angiography-derived index of microcirculatory resistance (A-IMR) is a less invasive method for assessing microcirculatory resistance. We aimed to evaluate MVS characteristics using A-IMR. Methods and Results:We retrospectively studied ANOCA patients who underwent acetylcholine spasm provocation tests (SPT). Patients were classified into no-spasm, epicardial spasm (ECS), or MVS groups. A-IMR was measured before and after SPT. Of 109 patients, 21 (19.3%) had MVS. The MVS group had more women (76.2% vs. 42.0%; P=0.01) than the other 2 groups combined. While pre-SPT A-IMR values were similar, post-SPT A-IMR after nitroglycerin was significantly higher in the MVS group than the no-spasm group, especially in the left anterior descending (LAD) artery (44.60 vs. 33.54; P=0.007). ∆A-IMR (post- minus pre-SPT) was significantly greater in the MVS group for both the LAD (9.89 vs. -9.26; P=0.001) and right coronary artery (RCA; 3.22 vs. -6.83; P=0.001). Multivariable analysis showed ∆A-IMR in the LAD and RCA were independently associated with MVS. Conclusions:Serial A-IMR assessment during SPT reveals sustained nitrate-resistant microvascular constriction in patients with MVS, which may confound standard post-SPT physiological assessments such as coronary flow reserve or IMR. These findings underscore the need for careful interpretation of physiological data in the presence of MVS.

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).

AIMS:Although the advantages of intra-coronary imaging guidance in percutaneous coronary intervention (PCI) have been reported, the advantage of optical coherence tomography (OCT) guided PCI has not been elucidated in patients with ST-elevation myocardial infarction (STEMI). This study assessed the association between OCT findings after stent implantation and 1-year outcomes in an all-comer STEMI population. METHODS AND RESULTS:The ATLAS-OCT trial was a prospective, multicentre, single-arm study enrolling STEMI patients within 24 h of symptom onset. OCT-guided PCI was preferred when feasible. This analysis included patients with analysable post-PCI OCT images. The primary endpoint was target vessel failure (TVF; all-cause death, target vessel myocardial infarction [TVMI], or target vessel revascularization [TVR]). OCT images were analysed independently, and outcomes assessed at 12 months. Of 632 patients, 439 (69.5%) underwent OCT-guided stenting with final analysable imaging. Mean minimal stent area (MSA) and stent expansion (SE) were 6.21 ± 2.27 mm² and 76.8 ± 15.6%, respectively. Optimization criteria (MSA > 4.5 mm² and/or SE > 70%) were met in 87.7%. Suboptimal expansion was associated with higher TVF (20.4% vs. 8.1%; HR 2.57, 95% CI: 1.29-5.11), driven by TVMI and TVR. Each 1 mm² MSA decrease and 10% SE reduction increased TVF odds by 23% and 33%, respectively. Minor OCT findings were not significantly associated with outcomes. CONCLUSION:In STEMI, suboptimal MSA and SE determined by OCT were associated with higher adverse event risk. These findings support OCT-guided PCI optimization to improve outcomes and warrant further evaluation in randomized trials. STUDY REGISTRATION:University Hospital Medical Information Network Clinical Trials Registry of Japan (UMIN-CTR number: 000048590).

BACKGROUND:Although myocardial extracellular volume fraction (ECV) derived from coronary computed tomography angiography (CCTA) is a robust prognostic marker across diverse cardiovascular pathologies, its precise pathophysiological determinants in patients with chronic coronary syndrome (CCS) remain poorly elucidated. METHODS:This retrospective study aimed to identify clinical and imaging factors independently associated with myocardial ECV in CCS patients. We analyzed 290 consecutive patients (mean age 66.6 ​± ​12.6 years) who underwent clinically indicated CCTA with a dedicated ECV protocol. Key exclusion criteria included prior coronary revascularization, acute or prior myocardial infarction, known cardiomyopathy, severe valvular disease, or arrhythmias to isolate CCS-specific associations. RESULTS:The median global myocardial ECV was 31.6% (IQR: 28.5-34.9%). Multivariable linear regression analysis identified female sex (β ​= ​2.610), H2FPEF score (β ​= ​0.909), left ventricular end-systolic diameter (LVDs; β ​= ​0.182), and coronary artery calcium score (CACS; β ​= ​0.001) as independent determinants of expanded ECV (all P ​< ​0.01). Notably, myocardial ECV exhibited a significant stepwise increase corresponding to the cumulative presence of these predictors (P ​< ​0.001), particularly in male patients. This relationship persisted regardless of the presence or anatomical severity of epicardial coronary artery stenosis, suggesting that ECV reflects myocardial interstitial remodeling that occurs independently of macrovascular obstruction. CONCLUSION:In patients with CCS, myocardial ECV is independently driven by female sex, H2FPEF score, LVDs, and CACS. These findings underscore that CCTA-derived ECV represents a multifactorial marker of myocardial health, necessitating an integrated interpretation of clinical and structural variables. Understanding these complex associations is crucial for refining the role of ECV in the risk stratification and personalized clinical management of patients with chronic coronary syndrome.

Pericoronary adipose tissue (PCAT) imaging has emerged as a promising noninvasive marker of coronary inflammation and an adjunctive risk-stratification tool beyond conventional coronary computed tomography angiography (CCTA) findings such as luminal stenosis and plaque morphology. The fat attenuation index (FAI), derived from CCTA, quantifies phenotypic changes in pericoronary fat driven by vascular inflammation. The CRISP-CT study demonstrated that elevated FAI around the right coronary artery independently predicted cardiac mortality. The ORFAN study further established that the FAI-Score-an artificial intelligence-adjusted derivative of raw PCAT attenuation-predicts cardiac events even in the absence of obstructive coronary artery disease. Multiple meta-analyses have consistently demonstrated that elevated PCAT attenuation is associated with an increased risk of major adverse cardiovascular events. It should be emphasized, however, that current evidence supports FAI/FAI-Score primarily as a prognostic marker; trial-level evidence that FAI-guided management decisions improve patient outcomes is not yet available. Beyond established prognostic applications, investigational uses include the identification of functionally significant lesions, acute coronary syndrome mechanism characterization, vasospastic angina prediction, myocardial infarction with non-obstructive coronary arteries assessment, treatment-response monitoring, and risk stratification in diabetic populations; these emerging applications require prospective validation. The fat radiomic profile, a machine-learning-derived extension, captures structural remodeling in pericoronary fat that persists beyond the acute inflammatory changes detected by FAI alone. However, substantial technical challenges remain. Reconstruction algorithms and tube voltage introduce measurement variability that can exceed the biological signal, and no major cardiovascular society has issued formal recommendations for routine clinical use. This review provides an overview of the biological rationale, measurement methodology, prognostic evidence, emerging and investigational applications, and current limitations of PCAT-based coronary inflammation imaging.

Background:Acute myocardial infarction is a reversible cause of shockable-rhythm out-of-hospital cardiac arrest. Prognosis, however, is strongly influenced by arrest circumstances and physiological severity. We assessed whether time to coronary reperfusion is independently associated with mortality in these patients undergoing primary percutaneous coronary intervention. Methods:We conducted a retrospective single-center cohort study of consecutive shockable-rhythm out-of-hospital cardiac arrest patients who underwent primary percutaneous coronary intervention for acute myocardial infarction (July 2011-July 2025). Door-to-reperfusion time was defined as the time from emergency department arrival to antegrade flow restoration in the culprit vessel. The primary endpoint was in-hospital death. Logistic regression evaluated correlates of mortality and predictors of delayed reperfusion (>90 min). Results:Among 141 patients (median age 63 years), 44 (31.2%) died. Median cardiopulmonary resuscitation time and door-to-reperfusion time were 20 and 91 min. Longer door-to-reperfusion time was associated with higher mortality (odds ratio 1.01 per minute; 95% confidence interval 1.00-1.03). Longer cardiopulmonary resuscitation time (odds ratio 1.04 per minute; 95% confidence interval 1.01-1.08), lower pH (per 0.1 increase: odds ratio 0.63; 95% confidence interval 0.45-0.88), and older age (odds ratio 1.08 per year; 95% confidence interval 1.03-1.15) were associated with mortality. Preprocedural computed tomography (odds ratio 3.73; 95% confidence interval 1.29-10.80) predicted delayed reperfusion. Conclusions:In shockable-rhythm out-of-hospital cardiac arrest due to acute myocardial infarction undergoing primary percutaneous coronary intervention, longer door-to-reperfusion time was associated with in-hospital mortality.Clinical Research Ethics Committee of the National Hospital Organization Disaster Medical Center (Approval No. 2025-39, Date 26 December 2025).

Background The honeycomb-like structure is an uncommon cause of myocardial ischaemia, detectable through high-resolution intracoronary imaging. Although percutaneous coronary intervention (PCI) for honeycomb-like structure has shown favourable outcomes, the relationship between PCI for honeycomb-like structure and subsequent improvement in cardiac function remains poorly understood.Case summary A 58-year-old male was referred to our hospital for exertional dyspnoea. He was diagnosed with heart failure, and echocardiography revealed a reduced left ventricular ejection fraction (LVEF) of 24%, with particularly severe hypokinesis observed in the left anterior descending artery (LAD) territory. Cardiac magnetic resonance imaging showed non-transmural late gadolinium enhancement predominantly in the endocardial layer of the anterior LV wall. Coronary angiography demonstrated diffuse moderate stenosis in the LAD, with fractional flow reserve (FFR) of 0.29, and optical coherence tomography revealed a honeycomb-like structure. Two everolimus-eluting stents were implanted in the LAD. Following the PCI, significant recovery of LV wall motion including the anterior and apical segments was observed, with LVEF increasing from 24% to 46%. The 1-year follow-up showed no worsening of heart failure.Discussion This is the first documentation of an ischaemic cardiomyopathy showing significant recovery of cardiac function after PCI targeting honeycomb-like structure. As reported in previous studies focusing on honeycomb-like structure, this case also exhibited angiographic underestimation of stenosis and low FFR value reflecting the true haemodynamic severity. The pathogenesis of honeycomb-like structure-thrombus formation and spontaneous recanalization-may have triggered ischaemic preconditioning, resulting in the development of hibernating myocardium, which could explain the viable myocardium in this case.

BackgroundThe clinical courses of acute myocarditis vary significantly, making accurate prognosis at presentation challenging. History taking is a fundamental skill in medicine, and assessing prodromal syndromes may aid prognostic stratification invarious acute cardiovascular diseases; however, its utility in myocarditis remains elusive. We aimed to investigate the association between prodromal symptoms and prognosis in acute myocarditis. MethodsWe analyzed admission data on acute myocarditis from a multicenter registry (Tokyo CCU Network Database) between January 2017 to December 2021. Prodromal symptoms were assessed by attending physicians and included chest pain, dyspnea, fever, cold symptoms, pain other than chest pain, gastrointestinal symptoms, dizziness, loss of appetite, palpitations, heartburn, and eyelid edema. The primary outcome was in-hospital death. Multivariable Cox regression assessed the association between prodromal symptoms and outcomes, adjusting for patient characteristics. ResultsAmong 261 acutely admitted patients, 187 (71.6%) exhibited prodromal symptoms, and 74 (28.3%) did not. Prodromal symptoms included chest pain (31.0%), dyspnea (25.0%), and fever (23.0%). The primary outcome occurred in 39 patients (14.9%): 19 patients (25.7%) without prodromal symptoms and 20 (10.7%) with prodromal symptoms (hazard ratio, 3.30; 95% confidence interval, 1.73 to 6.27; P<0.001). In the multivariable analysis, the absence of prodromal symptoms was associated with primary outcomes. Notably, this trend was further pronounced among the subgroup withheart failure (in-hospital mortality rate 48.6% versus 15.1%, P<0.001). ConclusionThe absence of prodromal symptoms was identified as novel factors in the prognosis of acute myocarditis, which may contribute to risk stratification and effective management.

AIMS:Coronary computed tomography angiography (CCTA) has evolved beyond anatomical assessment to include sophisticated tissue characterization. While an elevated perivascular fat attenuation index around the right coronary artery (FAI-RCA) is known to reflect coronary inflammation in vasospastic angina (VSA), recurrent vasospasms may also induce chronic subclinical myocardial injury and subsequent remodelling, potentially associated with an increased myocardial extracellular volume fraction (ECV). However, the diagnostic integration of ECV and FAI-RCA for identifying VSA in patients with angina with non-obstructive coronary arteries (ANOCA) remains to be elucidated. METHODS AND RESULTS:This study included consecutive ANOCA patients who underwent CCTA with a dedicated ECV protocol, followed by an invasive spasm provocation test. Comprehensive CCTA analysis quantified both FAI-RCA and the transmural ECV gradient (the difference between endocardial and epicardial ECV: ECVEndo - ECVEpi). Of the 100 patients analysed (mean age: 65.3 ± 11.8 years; 55% male), 27 were diagnosed with VSA. Multivariable logistic regression analysis identified transmural ECV gradient [odds ratio (OR): 1.12, 95% confidence interval (CI): 1.01-1.25], presence of myocardial bridging (MB) (OR: 3.49, 95% CI: 1.25-9.74), and high FAI-RCA (> -70.95 Hounsfield units [HU]) (OR: 5.79, 95% CI: 2.06-16.30) as significant independent predictors of VSA (all P < 0.05). Notably, the integration of transmural ECV gradient provided incremental diagnostic value beyond FAI-RCA and MB, as assessed by the Net Reclassification Improvement and Integrated Discrimination Improvement. CONCLUSION:A multi-parametric CCTA approach potentially identifies patients at high risk for VSA. The significant association of the transmural ECV gradient with VSA suggests that myocardial remodelling imaging provides a novel diagnostic window into the cumulative myocardial impact of vasospasm, independent of active adipose tissue inflammation and the presence of MB.

Background: The quantitative flow ratio (QFR), an angiography-based index for the assessment of coronary functional stenosis, correlates well with fractional flow reserve (FFR). In this study we explored the clinical significance of the difference between these values, calculated by subtracting FFR from QFR (delta QFR-FFR), in patients undergoing FFR-guided elective percutaneous coronary intervention (PCI). Methods and Results: This retrospective analysis included patients with chronic coronary syndrome who underwent FFR-guided PCI and comprehensive coronary functional assessments, including QFR. Patients were divided into tertiles based on pre-PCI delta QFR-FFR. We compared clinical and physiological characteristics and major adverse cardiovascular events (MACE; a composite of cardiac death, myocardial infarction, stroke, and heart failure requiring admission) among the 3 groups, and evaluated delta QFR-FFR as a predictor of MACE. Among 301 patients, lower delta QFR-FFR was associated with a lower QFR pullback pressure gradient, a higher index of microcirculatory resistance, lower microvascular resistance reserve, and reduced post-PCI coronary flow reserve, whereas post-PCI FFR was similar across tertiles. MACE occurred more frequently in patients with delta QFR-FFR less than-0.060 (log-rank P=0.006). Cox regression analysis identified lower delta QFR-FFR as an independent predictor of MACE. Conclusions: Pre-PCI delta QFR-FFR correlates with microvascular dysfunction and diffuse disease patterns. A lower delta QFR-FFR predicted an increased risk of MACE after FFR-guided revascularization, highlighting its potential clinical significance as a risk stratification tool.