Artificial intelligence-based quantitative coronary angiography (AI-QCA) was introduced to address manual QCA’s limitations in reproducibility and correction process. The present study aimed to assess the performance of an updated AI-QCA solution (MPXA-2000) in lesion detection and quantification using manual QCA as the reference standard, and to demonstrate its superiority over visual estimation. This multi-center retrospective study analyzed 1,076 coronary angiography images obtained from 420 patients, comparing AI-QCA and visual estimation against manual QCA as the reference standard. A lesion was classified as ‘detected’ when the minimum lumen diameter (MLD) identified by manual QCA fell within the boundaries of the lesion delineated by AI-QCA or visual estimation. The detected lesions were evaluated in terms of diameter stenosis (DS), MLD, and lesion length (LL). AI-QCA accurately detected lesions with a sensitivity of 93

BackgroundSex-related disparities in clinical outcomes following transcatheter aortic valve replacement (TAVR) and the impact of sex on clinical outcomes after TAVR among different racial groups are undetermined.ObjectivesThis study assessed whether sex-specific differences in baseline clinical and anatomical characteristics affect clinical outcomes after TAVR and investigated the impact of sex on clinical outcomes among different racial groups.MethodsThe TP-TAVR (Trans-Pacific TAVR) registry is a multinational cohort study of patients with severe aortic stenosis who underwent TAVR at 2 major centers in the United States and 1 major center in South Korea. The primary outcome was a composite of death from any cause, stroke, or rehospitalization after 1 year.ResultsThe incidence of the primary composite outcome was not significantly different between sexes (27.9% in men vs 28% in women; adjusted HR: 0.97; 95% CI: 0.79-1.20). This pattern was consistent in Asian (23.5% vs 23.3%; adjusted HR: 0.99; 95% CI: 0.69-1.41) and non-Asian (30.8% vs 31.6%; adjusted HR: 0.95; 95% CI: 0.72-1.24) cohorts, without a significant interaction between sex and racial group (P for interaction = 0.74). The adjusted risk for all-cause mortality was similar between sexes, regardless of racial group. However, the adjusted risk of stroke was significantly lower in male patients than in female patients, which was more prominent in the non-Asian cohort.ConclusionsDespite significantly different baseline and procedural characteristics, there were no sex-specific differences in the adjusted 1-year rates of primary composite outcomes and all-cause mortality, regardless of different racial groups. (Transpacific TAVR registry [TP-TAVR]; NCT03826264)

PURPOSE:The aim of this study was to assess the diagnostic performance of perfusion-only SPECT/CT (Q SPECT/CT) in comparison with that of ventilation/perfusion planar scintigraphy (V/Q planar), perfusion SPECT with ventilation scan (V/Q SPECT), and perfusion SPECT/CT with ventilation scan (V/Q SPECT/CT) in chronic thromboembolic pulmonary hypertension (CTEPH).PATIENTS AND METHODS:Patients with pulmonary hypertension who underwent ventilation-perfusion planar and SPECT/CT were retrospectively recruited. Two nuclear medicine physicians interpreted V/Q planar, V/Q SPECT, V/Q SPECT/CT, and Q SPECT/CT according to the European Association of Nuclear Medicine criteria. The diagnostic accuracy of these modalities for CTEPH was compared using a composite reference standard of pulmonary angiography, imaging test, cardiorespiratory assessment, and follow-up.RESULTS:A total of 192 patients were enrolled, including 85 with CTEPH. The sensitivity of Q SPECT/CT was 98.8%, which similar to that of V/Q planar (97.6%), V/Q SPECT (96.5%), or V/Q SPECT/CT (100.0%). In contrast, Q SPECT/CT exhibited significantly lower specificity (73.8%) compared with V/Q planar (86.9%, P = 0.001), V/Q SPECT (87.9%, P < 0.001), and V/Q SPECT/CT (88.8%, P < 0.001). The significantly lower specificity of Q SPECT/CT, compared with the 3 others, was observed in the subgroup aged ≥50 years ( P < 0.001 for all), but not in those <50 years.CONCLUSIONS:Q SPECT/CT exhibited lower specificity compared with V/Q planar, V/Q SPECT, and V/Q SPECT/CT in diagnosing CTEPH. It might underscore the essential role of a ventilation scan in patients with PH, even with the introduction of SPECT/CT.

BackgroundArtificial 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 intra-observer 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.MethodsThe FLASH (Fully automated quantitative coronary angiography versus optical coherence tomography guidance for coronary stent implantation) trial is a randomized, investigator-initiated, multicenter, open-label, non-inferiority 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.ResultsEnrollment 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.ConclusionThe 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.

The left main coronary artery (LMCA) supplies over 70% of the myocardium, and significant LMCA disease is associated with high morbidity and mortality. With remarkable advances in percutaneous coronary intervention (PCI), including stent technology, antithrombotic agents, and evolving procedural techniques, PCI has become an important treatment option in clinical practice guidelines for the revascularization of LMCA disease. In contemporary clinical practice, a heart-team approach to shared decision-making, considering clinical/anatomic factors along with patient preferences, is emphasized for patients with significant LMCA disease requiring myocardial revascularization. Furthermore, recent progress in PCI procedures combined with intravascular imaging or functional guidance has resulted in significant improvements in PCI outcomes, especially for complex lesions, including LMCA disease. Nevertheless, owing to inherent anatomic complexities and frequent multivessel involvement, several unmet issues remain regarding the determination of the appropriate treatment approach for significant LMCA disease, for which further clinical research is required. This contemporary review article provides a comprehensive overview of left main PCI based on current guidelines and underlying trial data, addresses important unresolved diagnostic and therapeutic issues, and identifies future perspectives likely to advance progress in this field.

BACKGROUND: The optimal functional evaluation of coronary artery stenosis in patients with severe aortic stenosis (AS) has not been established. The objective of the study was to evaluate the instantaneous wave-free ratio (iFR) and fractional flow reserve (FFR) in patients with and without severe AS. METHODS: We retrospectively investigated 395 lesions in 293 patients with severe AS and 2257 lesions in 1882 patients without severe AS between 2010 and 2022 from a subgroup of the Interventional Cardiology Research In-Cooperation Society FFR Registry. All patients had FFR values, and iFR was analyzed post hoc using dedicated software only in lesions with adequate resting pressure curves (311 lesions in patients with severe AS and 2257 lesions in patients with nonsevere AS). RESULTS: The incidence of iFR ≤0.89 was 66.6% and 31.8% ( P <0.001), while the incidence of FFR ≤0.80 was 45.3% and 43.9% ( P =0.60) in the severe AS group and the nonsevere AS group, respectively. In the severe AS group, most lesions (95.2%) with iFR >0.89 had FFR >0.80, while 36.2% of lesions with iFR ≤0.89 had FFR >0.80. During a median follow-up of 2 years, FFR ≤0.80 was significantly associated with deferred lesion failure (adjusted hazard ratio, 2.71 [95% CI, 1.08–6.80]; P =0.034), while iFR ≤0.89 showed no prognostic value (adjusted hazard ratio, 1.31 [95% CI, 0.47–3.60]; P =0.60) in the severe AS group. Lesions with iFR ≤0.89 and FFR >0.80, in particular, were not associated with a higher rate of deferred lesion failure at 3 years compared with lesions with iFR >0.89 (15.4% versus 17.0%; P =0.58). CONCLUSIONS: This study suggested that FFR appears to be less affected by the presence of severe AS and is more associated with prognosis. iFR may overestimate the functional severity of coronary artery disease without prognostic significance, yet it can be useful for excluding significant stenosis in patients with severe AS.

BACKGROUND AND AIMS The optimal follow-up surveillance strategy for high-risk diabetic patients with had undergone percutaneous coronary intervention (PCI) remains unknown. METHODS The POST-PCI (Pragmatic Trial Comparing Symptom-Oriented versus Routine Stress Testing in High-Risk Patients Undergoing Percutaneous Coronary Intervention) study was a randomized trial comparing a follow-up strategy of routine functional testing at 1 year vs. standard care alone after high-risk PCI. Randomization was stratified according to diabetes status. The primary outcome was a composite of death from any cause, myocardial infarction, or hospitalization for unstable angina at 2 years. RESULTS Among 1706 randomized patients, participants with diabetes (n = 660, 38.7%) had more frequent comorbidities and a higher prevalence of complex anatomical or procedural characteristics than those without diabetes (n = 1046, 61.3%). Patients with diabetes had a 52% greater risk of primary composite events [hazard ratio (HR) 1.52; 95% confidence interval (CI) 1.02-2.27; P = .039]. The 2-year incidences of the primary composite outcome were similar between strategies of routine functional testing or standard care alone in diabetic patients (7.1% vs. 7.5%; HR 0.94; 95% CI 0.53-1.66; P = .82) and non-diabetic patients (4.6% vs. 5.1%; HR 0.89; 95% CI 0.51-1.55; P = .68) (interaction term for diabetes: P = .91). The incidences of invasive coronary angiography and repeat revascularization after 1 year were higher in the routine functional-testing group than the standard-care group irrespective of diabetes status. CONCLUSIONS Despite being at higher risk for adverse clinical events, patients with diabetes who had undergone high-risk PCI did not derive incremental benefit from routine surveillance stress testing compared with standard care alone during follow-up.

The impact of complete revascularization (CR), achieved through the recanalization of coronary chronic total occlusions (CTOs), on long-term patient outcomes remains uncertain.To evaluate this in patients who achieved CR after CTO-PCI with those who did not due to deferred CTO-PCI, the Asan Medical Center Registry was reviewed to identify coronary artery disease (CAD) patients with CTOs treated between January 2003 and December 2018. Patients were included with single-vessel disease with CTO and with multivessel disease who had undergone revascularization for non-CTO lesions. These subjects were divided into those who achieved CR with CTO-PCI and those who did not due to deferred CTO-PCI. Their outcomes were compared following 1:1 propensity score matching. Of the 2,746 enrolled CAD patients with CTOs, 1,837 achieved CR with CTO-PCI and 909 did not. Propensity score matching yielded 653 patient pairs. The CR-achieving group had a significantly lower 10-year risk of the primary composite outcome of death, myocardial infarction, stroke, or repeat revascularization (hazard ratio [HR]: 0.57; 95% confidence interval [CI]: 0.46–0.72; P < 0.001), as well as significantly lower risks of death (HR: 0.66; 95% CI: 0.51–0.87; P = 0.003) and repeat revascularization (HR: 0.67; 95% CI: 0.48–0.95; P = 0.023). CR was beneficial in all subgroups, including patients with major cardiovascular risk factors such as older age, hypertension, diabetes, and advanced CAD. Compared with incomplete revascularization, CR may significantly reduce the 10-year incidence of major adverse cardiac events in patients with CTO.

BackgroundAcute coronary syndrome and sudden cardiac death are often caused by rupture and thrombosis of lipid-rich atherosclerotic coronary plaques (known as vulnerable plaques), many of which are non-flow-limiting. The safety and effectiveness of focal preventive therapy with percutaneous coronary intervention of vulnerable plaques in reducing adverse cardiac events are unknown. We aimed to assess whether preventive percutaneous coronary intervention of non-flow-limiting vulnerable plaques improves clinical outcomes compared with optimal medical therapy alone.MethodsPREVENT was a multicentre, open-label, randomised controlled trial done at 15 research hospitals in four countries (South Korea, Japan, Taiwan, and New Zealand). Patients aged 18 years or older with non-flow-limiting (fractional flow reserve >0·80) vulnerable coronary plaques identified by intracoronary imaging were randomly assigned (1:1) to either percutaneous coronary intervention plus optimal medical therapy or optimal medical therapy alone, in block sizes of 4 or 6, stratified by diabetes status and the performance of percutaneous coronary intervention in a non-study target vessel. Follow-up continued annually in all enrolled patients until the last enrolled patient reached 2 years after randomisation. The primary outcome was a composite of death from cardiac causes, target-vessel myocardial infarction, ischaemia-driven target-vessel revascularisation, or hospitalisation for unstable or progressive angina, assessed in the intention-to-treat population at 2 years. Time-to-first-event estimates were calculated with the Kaplan–Meier method and were compared with the log-rank test. This report is the principal analysis from the trial and includes all long-term analysed data. The trial is registered at ClinicalTrials.gov, NCT02316886, and is complete.FindingsBetween Sept 23, 2015, and Sept 29, 2021, 5627 patients were screened for eligibility, 1606 of whom were enrolled and randomly assigned to percutaneous coronary intervention (n=803) or optimal medical therapy alone (n=803). 1177 (73%) patients were men and 429 (27%) were women. 2-year follow-up for the primary outcome assessment was completed in 1556 (97%) patients (percutaneous coronary intervention group n=780; optimal medical therapy group n=776). At 2 years, the primary outcome occurred in three (0·4%) patients in the percutaneous coronary intervention group and in 27 (3·4%) patients in the medical therapy group (absolute difference –3·0 percentage points [95% CI –4·4 to –1·8]; p=0·0003). The effect of preventive percutaneous coronary intervention was directionally consistent for each component of the primary composite outcome. Serious clinical or adverse events did not differ between the percutaneous coronary intervention group and the medical therapy group: at 2 years, four (0·5%) versus ten (1·3%) patients died (absolute difference –0·8 percentage points [95% CI –1·7 to 0·2]) and nine (1·1%) versus 13 (1·7%) patients had myocardial infarction (absolute difference –0·5 percentage points [–1·7 to 0·6]).InterpretationIn patients with non-flow-limiting vulnerable coronary plaques, preventive percutaneous coronary intervention reduced major adverse cardiac events arising from high-risk vulnerable plaques, compared with optimal medical therapy alone. Given that PREVENT is the first large trial to show the potential effect of the focal treatment for vulnerable plaques, these findings support consideration to expand indications for percutaneous coronary intervention to include non-flow-limiting, high-risk vulnerable plaques.FundingThe CardioVascular Research Foundation, Abbott, Yuhan Corp, CAH-Cordis, Philips, and Infraredx, a Nipro company.

BACKGROUND Optical coherence tomography (OCT) and intravascular ultrasound (IVUS) have shown comparable outcomes in guiding percutaneous coronary intervention (PCI). However, their comparative effectiveness in complex coronary artery lesions remains unclear. OBJECTIVES This study compared the effectiveness and safety of OCT-guided vs IVUS-guided PCI for complex coronary artery lesions. METHODS This was a prespecified, main subgroup analysis of complex coronary artery lesions in the OCTIVUS (Optical Coherence Tomography Versus Intravascular Ultrasound Guided Percutaneous Coronary Intervention) trial, which included unprotected left main disease, bifurcation disease, an aorto-ostial lesion, a chronic total occlusion, a severely calcified lesion, an in-stent restenotic lesion, a diffuse long lesion, or multivessel PCI. The primary endpoint was a composite of death from cardiac causes, target vessel-related myocardial infarction, or ischemia-driven target vessel revascularization. RESULTS In 2,008 randomized patients, 1,475 (73.5%) underwent imaging -guided PCI for complex coronary artery lesions; 719 (48.7%) received OCT-guided and 756 (51.3%) IVUS-guided PCI. At a median follow-up of 2.0 years, primary endpoint event had occurred in 47 patients (6.5%) in the OCT-guided group and in 56 patients (7.4%) in the IVUS-guided group (HR: 0.87; 95% CI: 0.59-1.29; P = 0.50). These findings were consistent in adjusted analyses. The incidence of contrast -induced nephropathy was similar between the 2 groups (1.9% vs 1.5%; P = 0.46). The incidence of major procedural complications was lower in the OCT-guided group than in the IVUS-guided group (1.7% vs 3.4%; P = 0.03). CONCLUSIONS Among patients with complex coronary artery lesions, OCT-guided PCI showed a similar risk of primary composite event of death from cardiac causes, target vessel-related myocardial infarction, or target vessel revascularization as compared with IVUS-guided PCI. (Optical Coherence Tomography Versus Intravascular Ultrasound Guided Percutaneous Coronary Intervention [OCTIVUS]; NCT03394079) (J Am Coll Cardiol 2024;83:401-413) (c) 2024 by the American College of Cardiology Foundation.

BACKGROUND:Recently developed artificial intelligence-based coronary angiography (AI-QCA, fully automated) provides real-time, objective, and reproducible quantitative analysis of coronary angiography without requiring additional time or labor. OBJECTIVES:This study aimed to evaluate the efficacy of AI-QCA-assisted percutaneous coronary intervention (PCI) compared to optical coherence tomography (OCT)-guided PCI in terms of post-PCI results. METHODS:This trial enrolled 400 patients with significant coronary artery disease undergoing PCI from 13 participating centers in South Korea. Patients were randomized in a 1:1 ratio to either AI-QCA-assisted or OCT-guided PCI. The primary endpoint was the post-PCI minimal stent area (MSA) assessed by OCT. The noninferiority of AI-QCA-assisted PCI to OCT-guided PCI regarding the post-PCI MSA was tested with a noninferiority margin of 0.8 mm2. RESULTS:A total of 395 patients (199 in the AI-QCA group and 196 in the OCT group) were included in the primary endpoint analysis. The post-PCI MSA was 6.3 ± 2.2 mm2 in the AI-QCA group and 6.2 ± 2.2 mm2 in the OCT group (difference, -0.16; 95% CI: -0.59 to 0.28; P for noninferiority < 0.001). Other OCT-defined endpoints, such as stent underexpansion (50.8% [101/199] vs 54.6% [107/196]; P = 0.48), dissection (15.6% [31/199] vs 12.8% [25/196]; P = 0.42), and untreated reference segment disease (15.1% [30/199] vs 13.3% [26/196]; P = 0.61), were not significantly different between groups, except for a higher incidence of stent malapposition in the AI-QCA group (13.6% [27/199] vs 5.6 [11/196]; P = 0.007). CONCLUSIONS:This study demonstrated the noninferiority of AI-QCA-assisted PCI to OCT-guided PCI in achieving MSA with comparable OCT-defined endpoints. (Fully Automated Quantitative Coronary Angiography Versus Optical Coherence Tomography Guidance for Coronary Stent Implantation [FLASH]; NCT05388357).

BackgroundPrognostic value of poststenting fractional flow reserve (FFR) remains uncertain in patients undergoing an imaging-guided optimal stenting strategy.ObjectivesThe authors evaluated the prognostic value of poststenting FFR according to the intracoronary imaging-guided lesion preparation, stent sizing, and postdilation (iPSP) strategy to optimize stent outcomes.MethodsPoststenting FFR assessment was performed in 1,108 lesions in 1,005 patients from the IRIS-FFR registry. The primary outcome was target vessel failure (TVF), a composite of cardiac death, target vessel myocardial infarction, and target vessel revascularization at 5 years.ResultsAt the index procedure, 326 lesions (29.4%) were treated using all 3 parts of the iPSP strategy. In the overall population, poststenting FFR was significantly associated with the risk of TVF at 5 years (per 0.01 increase of FFR, adjusted HR [aHR]: 0.94; 95% CI: 0.90-0.98; P = 0.004). Significant interaction was detected between poststenting FFR and the iPSP strategy on the risk of TVF at 5 years (P = 0.045 for interaction). In the iPSP group, poststenting FFR was not associated with the risk of TVF at 5 years (per 0.01 increase of FFR, aHR: 1.00; 95% CI: 0.96-1.05; P = 0.95), whereas a significant association between poststenting FFR and TVF at 5 years was observed in the no iPSP group (per 0.01 increase of FFR, aHR: 0.94; 95% CI: 0.90-0.99; P = 0.009).ConclusionsPoststenting FFR showed a significant association with cardiac events. However, its prognostic value appeared to be limited after the application of an imaging-guided optimal stenting strategy.

Despite the use of conventional dual antiplatelet therapy (DAPT) after percutaneous coronary intervention (PCI), the risk of adverse events remains high among patients with increased thrombotic risk. Until recently, the optimal antiplatelet strategy to balance the ischaemic and bleeding risks in patients who are undergoing complex high-risk PCI has been unclear. The TAILored Versus COnventional AntithRombotic StratEgy IntenDed for Complex HIgh-Risk PCI (TAILORED-CHIP) trial is an investigator-initiated, multicentre, prospective randomised trial to evaluate the efficacy and safety of a time-dependent tailored antiplatelet therapy with an early (<6 months post-PCI) escalation (low-dose ticagrelor at 60 mg twice daily plus aspirin) and a late (>6 months post-PCI) de-escalation (clopidogrel monotherapy) in patients undergoing complex high-risk PCI as compared with standard DAPT (clopidogrel plus aspirin for 12 months). Eligible patients had to have at least one high-risk anatomical or procedural feature or clinical characteristic associated with an increased risk of ischaemic or thrombotic events. The primary endpoint was the net clinical outcome, a composite of death from any cause, myocardial infarction, stroke, stent thrombosis, urgent revascularisation, or clinically relevant bleeding (Bleeding Academic Research Consortium type 2, 3, or 5) at 12 months after randomisation. (ClinicalTrials.gov: NCT03465644).

Background This study aimed to investigate the hemodynamic and anatomic factors associated with sinus thrombosis following transcatheter aortic valve replacement (TAVR), integrating in vivo patient data analysis and in vitro experiments. Methods and Results Postprocedural, 4‐dimensional, multiphase computed tomography data from 211 patients enrolled in the ADAPT‐TAVR (Anticoagulation Versus Dual Antiplatelet Therapy for Prevention of Leaflet Thrombosis and Cerebral Embolization After Transcatheter Aortic Valve Replacement) study were analyzed. The prevalence of native sinus thrombosis was examined in relation to valve type, implant depth, and anatomic features. In vitro experiments used particle image velocimetry to observe changes in sinus flow based on the transcatheter heart valves (23‐mm SAPIEN3, Edwards Lifesciences; and 29‐mm CoreValve, Medtronic) height and coronary artery flow. Native sinus thrombosis was more common in self‐expanding valves (39.1% versus 14.9%, P =0.004). In per‐cusp analysis of in vivo patient data, adjusted transcatheter heart valve implant depth (odds ratio, 1.2 [95% CI, 1.1–1.3]; P <0.001), noncoronary sinus of Valsalva (odds ratio, 4.0 [95% CI, 2.0–7.8]; P <0.001), sinus inflow diameter (odds ratio, 0.8 [95% CI, 0.6–0.9]; P =0.008), and implanted valve size (odds ratio, 0.8 [95% CI, 0.7–1.0]; P =0.025) were significant factors associated with native sinus thrombosis. In the in vitro experiments, CoreValve showed noticeable flow stasis compared with SAPIEN3. High‐positioned SAPIEN3 was linked to reduced velocity within the native sinus of Valsalva. Coronary artery flow led to higher sinus velocity and improved particle washout, reducing sinus thrombosis risk. Conclusions This study provides insights into the relationship between transcatheter heart valve deployment and native sinus thrombosis, emphasizing the role of anatomic factors in relation to the risk of sinus thrombosis.