Temporal trend and regional disparity in the investigations for stable chest pain in Europe: An insight from the PIONEER IV trial.

Coronary CT angiography (CCTA) and fractional flow reserve with CCTA (FFRCT) have been endorsed by the ACC/AHA Chest Pain guidelines to streamline the diagnosis of coronary artery disease (CAD), but there is still a significant lack of adherence. In our study of 673 stable chest patients without known CAD from 5 European countries, we found that CCTA is the most common noninvasive diagnostic test, but nearly 40 â€‹% of them still underwent upfront CAD. Additionally, there was no temporal improvement trend, and the integration of FFRCT is low. We highlighted the urgent need to improve diagnostic processes and update reimbursement policies.

Safety, efficacy, and optical coherence tomography insights into intravascular lithotripsy for the modification of non-eruptive calcified nodules: A prospective observational study.

BACKGROUND: Non-eruptive calcium nodules (CNs) are commonly seen in heavily calcified coronary artery disease. They are the most difficult subset for modification, and may result in stent damage, malapposition and under-expansion. There are only limited options available for non-eruptive CN modification. Intravascular lithotripsy (IVL) is being explored as a potentially safe and effective modality in these lesions. AIMS: This study aimed to investigate the safety and efficacy of the use of IVL for the modification of non-eruptive CNs. The study also explored the OCT features of calcium nodule modification by IVL. METHODS: This is a single-center, prospective, observational study in which patients with angiographic heavy calcification and non-eruptive CN on OCT and undergoing PCI were enrolled. The primary safety endpoint was freedom from perforation, no-reflow/slow flow, flow-limiting dissection after IVL therapy, and major adverse cardiac events (MACE) during hospitalization and at 30 days. MACE was defined as a composite of cardiac death, myocardial infarction (MI), and ischemia-driven target lesion revascularization (TLR). The primary efficacy endpoint was procedural success, defined as residual diameter stenosis of <30% on angiography and stent expansion of more than 80% as assessed by OCT. RESULTS: A total of 21 patients with 54 non-eruptive CNs undergoing PCI were prospectively enrolled in the study. Before IVL, OCT revealed a mean calcium score of 3.7 ± 0.5 and a mean MLA at CN of 3.9 ± 2.1 mm2. Following IVL, OCT revealed calcium fractures in 40 out of 54 (74.1%) CNs with an average of 1.05 ± 0.72 fractures per CN. Fractures were predominantly observed at the base of the CN (80%). Post IVL, the mean MLA at CN increased to 4.9 ± 2.3 mm2. After PCI, the mean MSA at the CN was 7.9 ± 2.5 mm2. Optimal stent expansion (stent expansion >80%) at the CN was achieved in 85.71% of patients. All patients remained free from MACE during hospitalization and at the 30-day follow-up. At 1-year follow-up, all-cause death had occurred in 3 (14.3%) patients. CONCLUSIONS: This single-arm study demonstrated the safety, efficacy, and utility of the IVL in a subset of patients with non-eruptive calcified nodules. In this study, minimal procedural complications, excellent lesion modifications, and favorable 30-day and 1-year outcomes were observed.

Long-term outcomes following bioresorbable vascular scaffolds.

INTRODUCTION: The higher scaffold thrombosis rates observed with the first-generation bioresorbable scaffolds (BRSs) compared to conventional drug-eluting stents were likely due in part to bioresorbable polymers having insufficient radial strength, necessitating larger strut profiles. Meta-analysis of the long-term outcomes from the first-generation Absorb bioresorbable vascular scaffold (BVS) showed that this period of excess risk ended at 3 years. Therefore, current attention has been focused on improving early outcomes by increasing the scaffold's tensile strength and reducing strut thickness. AREAS COVERED: This review summaries the lessons learned from the first-generation BRS. It updates the long-term clinical outcomes of trials evaluating the ABSORB BVS and metallic alloy-based BRS. In addition, it reviews the next-generation BRSs manufactured in Asia. EXPERT OPINION: Critical areas to improve the performance and safety of biodegradable scaffolds include further development in material science, surface modification, delivery systems, and long-term follow-up studies.

Quantitative coronary computed tomography assessment for differentiating between total occlusions and severe stenoses.

BACKGROUNDS: The impact of quantitative assessment to differentiate total occlusions (TOs) from severe stenoses on coronary computed tomography angiography (CCTA) remains unknown. OBJECTIVE: This study investigated whether quantitative characteristics assessed on CCTA could help differentiate a TO from a severe stenosis on invasive coronary angiography (ICA). METHODS: This study is a sub-analysis of the FASTTRACK CABG (NCT04142021) in which both CCTA and ICA were routinely performed. Quantitative analysis was performed with semi-automated CCTA plaque-analysis software. Blinded analysts compared TOs on CCTA, defined as a complete lack of contrast opacification within the coronary occlusion, with corresponding ICA. RESULTS: Eighty-four TOs were seen on CCTA in 59 of the 114 patients enrolled in the trial. The concordance in diagnosing a TO between ICA and CCTA was 56.0% (n â€‹= â€‹47). Compared to severe stenoses, TOs had a significantly longer lesion length (25.1 â€‹± â€‹23.0 â€‹mm vs 9.4 â€‹± â€‹11.2 â€‹mm, P â€‹< â€‹0.001). The best cut-off value to differentiate a TO from severe stenosis was a lesion length of 5.5 â€‹mm (area under the curve 0.77, 95% CI: 0.66-0.87), with a 91.1% sensitivity and 61.1% specificity. Dense calcium percentage atheroma volume (PAV) was significantly higher in TOs compared to severe stenoses (18.7 â€‹± â€‹19.6% vs. 6.6 â€‹± â€‹13.0%, P â€‹< â€‹0.001), whilst the opposite was seen for fibro-fatty PAV (31.3 â€‹± â€‹14.2% vs. 19.5 â€‹± â€‹10.5%, P â€‹< â€‹0.001). On a multivariable logistic regression analysis, lesion length (>5.5 â€‹mm) was the only parameter associated with differentiating a TO from a severe stenosis. CONCLUSION: In quantitative CCTA analysis, a lesion length >5.5 â€‹mm was the only independent predictor differentiating a TO from a severe stenosis. NCT REGISTRATION NUMBER: NCT04142021.

Assessment of Coronary Stenoses for Percutaneous Coronary Intervention: A Systematic Review and Network Meta-Analysis of Randomized Trials.

Evidence regarding the comparative efficacy of the different methods to determine the significance of coronary stenoses in the catheterization laboratory is lacking. We aimed to compare all available methods guiding the decision to perform percutaneous coronary intervention (PCI). We searched Medline, Embase, and CENTRAL until October 5, 2023. We included trials that randomized patients with greater than 30% stenoses who were considered for PCI and reported major adverse cardiovascular events (MACE). We performed a frequentist random-effects network meta-analysis and assessed the certainty of evidence using the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. We included 15 trials with 16,333 participants with a mean weighted follow-up of 34 months. The trials contained a median of 49.3% (interquartile range: 32.6%, 100%) acute coronary syndrome participants. Quantitative flow ratio (QFR) was associated with a decreased risk of MACE compared with coronary angiography (CA) (risk ratio [RR] 0.68, 95% confidence interval [CI] 0.56 to 0.82, high certainty), fractional flow reserve (FFR) (RR 0.73, 95% CI 0.58 to 0.92, moderate certainty), and instantaneous wave-free ratio (iFR) (RR 0.63, 95% CI 0.49 to 0.82, moderate certainty), and ranked first for MACE (88.1% probability of being the best). FFR (RR 0.93, 95% CI 0.82 to 1.06, moderate certainty) and iFR (RR 1.07, 95% CI 0.90 to 1.28, moderate certainty) likely did not decrease the risk of MACE compared with CA. Intravascular imaging may not be associated with a significant decrease in MACE compared with CA (RR 0.85, 95% CI 0.62 to 1.17, low certainty) when used to guide the decision to perform PCI. In conclusion, a decision to perform PCI based on QFR was associated with a decreased risk of MACE compared with CA, FFR, and iFR in a mixed stable coronary disease and acute coronary syndrome population. These hypothesis-generating findings should be validated in large, randomized, head-to-head trials.

Systematic screening by a heart team and a machine learning approach contribute to unraveling novel risk factors in revascularization candidates with complex coronary artery disease.

INTRODUCTION: The baseline characteristics affecting mortality following percutaneous or surgical revascularization in patients with left main and / or 3­vessel coronary artery disease (CAD) observed in real­world practice differ from those established in randomized controlled trials (RCTs) due to the constraints of inclusion / exclusion criteria. OBJECTIVES: This study aimed to assess whether systematic screening enables identification of novel and registry­specific baseline patient characteristics influencing long­term mortality. PATIENT AND METHODS: Least absolute shrinkage and selection operator (LASSO) regression was used to screen 42 baseline patient characteristics shared by the SYNTAX (Synergy between Percutaneous Coronary Intervention with Taxus and Cardiac Surgery) trial and a single­center Polish registry of 1035 consecutive patients with complex CAD who received revascularization and were followed-up for 5 years. After screening, a classic Cox regression analysis was performed to examine the suitability of a linear model for predicting 5­year mortality, which was then compared with the mortality predicted in the same cohort using the SYNTAX score II 2020 (SS2020). RESULTS: The 5­year mortality rate in the registry was 12.3%, and the strongest predictors were pulmonary hypertension, chronic obstructive pulmonary disease, and insulin­dependent diabetes. In an internal validation, the linear model constructed after LASSO screening and combined with a classic Cox regression analysis improved the prediction of 5­year mortality, as compared with the SS2020 (concordance index of 0.92 and 0.75, respectively). CONCLUSIONS: A machine learning approach improved the detection of registry­specific risk factors in all­comer patients amenable to surgical or percutaneous revascularization who were evaluated by a heart team. The risk factors identified in RCTs are not necessarily the same as those detected in real clinical practice when systematic screening is applied.

The Impact of Microvascular Resistance Reserve on the Outcome of Patients With STEMI.

BACKGROUND: Microvascular resistance reserve (MRR) can characterize coronary microvascular dysfunction (CMD); however, its prognostic impact in ST-segment elevation myocardial infarction (STEMI) patients remains undefined. OBJECTIVES: This study sought to investigate the prevalence of CMD in STEMI patients and to elucidate the prognostic performance of MRR. METHODS: This prospective cohort study enrolled 210 STEMI patients with multivessel disease who underwent successful revascularization and returned at 3 months for coronary physiology assessments with bolus thermodilution. The prevalence of CMD (MRR <3) and the association between MRR and major adverse cardiovascular and cerebrovascular events (MACCEs) at 12 months were investigated. RESULTS: The median age of patients was 65 years, and 59.5% were men. At the 3-month follow-up, 56 patients (27%) had CMD (MRR <3.0). The number of MACCEs at 12 months was higher in patients with vs without CMD (48.2% vs 11.0%; P < 0.001). MRR was independently associated with 12-month MACCEs (HR: 0.45 per unit increase; 95% CI: 0.31-0.67; P < 0.001) and with stroke, heart failure, and poorer recovery in left ventricular systolic function. The areas under the receiver-operating characteristic curves for predicting MACCEs at 12 months with fractional flow reserve, coronary flow reserve (CFR), the index of microvascular resistance (IMR), and MRR were 0.609, 0.762, 0.781, and 0.743, respectively. The prognostic performance of CFR, IMR, and MRR were all comparable. CONCLUSIONS: The novel parameter MRR is a prognostic marker of MACCEs in STEMI patients with a comparable performance to CFR and IMR. (Impact of TMAO Serum Levels on Hyperemic IMR in STEMI Patients [TAMIR]; NCT05406297).

Frequency of periprocedural myocardial injury and infarction stratified by cardiac troponin I and cardiac troponin T.

BACKGROUND: There are different definitions of periprocedural myocardial infarction (PPMI) both in terms of thresholds for cardiac biomarkers and the ancillary criteria for myocardial ischemia. Cardiac Troponin I (cTnI) and cardiac Troponin T (cTnT) are used interchangeably to diagnose PPMI. OBJECTIVES: This study evaluated the frequency of periprocedural myocardial injury and infarction as defined by the Society of Cardiovascular Angiography & Interventions (SCAI), the Academic Research Consortium-2 (ARC-2), and the 4th Universal definition of MI (4UDMI) stratified using cTnT versus cTnI, among patients with chronic coronary syndrome (CCS) and unstable angina. RESULTS: Among 830 patients, PPMI rates according to the SCAI, ARC2 and 4UDMI criteria were 4.34 %, 2.05 %, and 4.94 % respectively, with higher rates seen for all definitions when using cTnI versus cTnT (SCAI: 9.84 % vs. 1.91 %, p < 0.001; ARC 2: 3.15 % vs. 1.56 %, p = 0.136; and 4UDMI 5.91 % vs. 4.51 %, p = 0.391). Minor and major periprocedural myocardial injury was respectively observed in 58.31 % and 27.10 % of patients, with rates of both significantly higher when using cTnI versus cTnT (Minor: 69.29 % vs. 53.47 %, p < 0.001, Major: 49.21 % vs. 17.36 %, p < 0.001). CONCLUSIONS: Among patients with CCS and unstable angina, PPMIs defined by SCAI occurred more frequently when using cTnI as opposed to cTnT, whereas the type of troponin had no impact on the incidence of PPMIs according to the ARC-2 and 4UDMI.

γ-Glutamyl Transferase and Long-Term Survival in the SYNTAXES Trial: Is It Just the Liver?

BACKGROUND: Recently, machine learning algorithms have identified preprocedural γ-glutamyl transferase (GGT) as a significant predictor of long-term mortality after coronary revascularization in the SYNTAX (Synergy Between PCI [Percutaneous Coronary Intervention] With Taxus and Cardiac Surgery) trial. The aim of the present study is to investigate the impact of preprocedural GGT on 10-year all-cause mortality in patients with complex coronary artery disease after revascularization. METHODS AND RESULTS: The SYNTAX trial was a randomized trial comparing PCI with coronary artery bypass grafting in 1800 patients with complex coronary artery disease. The present report is a post hoc subanalysis of the SYNTAXES (Synergy Between PCI With Taxus and Cardiac Surgery Extended Survival) trial, an investigator-driven extended 10-year follow-up of the SYNTAX trial. The association between preprocedural GGT and 10-year all-cause mortality was investigated. The mean values of GGT for men and women were 43.5 (SD, 48.5) and 36.4 (SD, 46.1) U/L, respectively. In multivariable Cox regression models adjusted by traditional risk factors, GGT was an independent predictor for all-cause death at 10-year follow-up, and each SD increase in log-GGT was associated with a 1.24-fold risk of all cause death at 10-year follow-up (95% CI, 1.10-1.40). According to previously reported sex-related GGT thresholds, patients with higher GGT level had a 1.74-fold risk of all-cause death at 10-year follow-up (95% CI, 1.32-2.29) compared with patients with lower GGT level. CONCLUSIONS: Preprocedural GGT is an independent predictor of 10-year mortality after coronary revascularization in patients with complex coronary artery disease. In patients with elevated GGT, strong secondary prevention may be required after revascularization and must be studied prospectively. REGISTRATION: URL: https://clinicaltrials.gov/study/NCT03417050.

Geographic disparity of pathophysiological coronary artery disease characteristics: Insights from ASET trials.

BACKGROUND: The geographical disparity in the pathophysiological pattern of coronary artery disease (CAD) among patients undergoing percutaneous coronary intervention (PCI) is unknown. OBJECTIVES: To elucidate the geographical variance in the pathophysiological characteristics of CAD. METHODS: Physiological indices derived from angiography-based fractional flow reserve pullbacks from patients with chronic coronary syndrome enrolled in the ASET Japan (n = 206) and ASET Brazil (n = 201) studies, which shared the same eligibility criteria, were analysed. The pathophysiological patterns of CAD were characterised using Murray law-based quantitative flow ratio (µQFR)-derived indices acquired from pre-PCI angiograms. The diffuseness of CAD was defined by the µQFR pullback pressure gradient index. RESULTS: Significant functional stenoses pre-PCI (µQFR ≤0.80) were more frequent in ASET Japan compared to ASET Brazil (89.9% vs. 67.5%, p < 0.001), as were rates of a post-PCI µQFR <0.91 (22.1% vs. 12.9%, p = 0.013). In the multivariable analysis, pre-procedural µQFR and diffuse disease were independent factors for predicting a post-PCI µQFR <0.91, which contributed to the different rates of post-PCI µQFR ≥0.91 between the studies. Among vessels with a post-PCI µQFR <0.91, a consistent diffuse pattern of CAD pre- and post-PCI occurred in 78.3% and 76.7% of patients in ASET Japan and Brazil, respectively; only 6.3% (Japan) and 10.0% (Brazil) of vessels had a major residual gradient. Independent risk factors for diffuse disease were diabetes mellitus in ASET Japan, and age and male gender in Brazil. CONCLUSIONS: There was geographic disparity in pre-procedural angiography-based pathophysiological characteristics. The combined pre-procedural physiological assessment of vessel µQFR and diffuseness of CAD may potentially identify patients who will benefit most from PCI.

Association between three-year mortality after transcatheter aortic valve implantation and paravalvular regurgitation graded by videodensitometry in comparison with visual grading.

BACKGROUND: Estimation of regurgitant fraction by videodensitometry (VD-AR) of aortic root angiograms is a new tool for objective grading of paravalvular regurgitation (PVR) after transcatheter aortic valve implantation (TAVI). Stratification with boundaries at 6% and 17% has been proposed to reflect "none/trace", "mild" and "moderate or higher" PVR. OBJECTIVE: We sought to investigate the association of strata of VD-AR with 3-year mortality and to compare VD-AR with visual grading of angiograms. METHODS: We interrogated our database for patients undergoing transfemoral TAVI from 2008 to 2018. Vital status of the patients was obtained from population registers. To test differences in survival and estimate adjusted hazard ratios (HRs) we fitted Cox models. RESULTS: Our retrospective study included 699 patients with evaluable angiograms at completion of the TAVI procedure. Cumulative 3-year mortality was 35.0% in 261 (37.3%) patients with VD-AR < 6%, 33.9% in 325 (46.5%) patients with VD-AR between 6 and 17% (HR [95% confidence interval] 1.06 [0.80-1.42]; P = 0.684) and 47.2% in 113 (16.2%) patients with VD-AR > 17% (HR 1.57 [1.11-2.22]; P = 0.011). Visually, PVR was graded as "none/trace" in 470 (67.2%) patients, as "mild" in 219 (31.3%) and as "moderate" in 10 (1.4%). Both mild PVR and moderate PVR on visual grading were significantly associated with mortality (HRs 1.31 [1.12-1.54]; P = 0.001 and 1.92 [1.13-3.24]; P = 0.015; respectively). CONCLUSIONS: VD-AR > 17%, but not VD-AR 6-17%, was independently associated with mortality. Compared with subjective visual evaluation, VD-AR resulted in a smaller proportion of patients with PVR classified as prognostically relevant.

Preprocedural physiological assessment of coronary disease patterns to predict haemodynamic outcomes post-PCI.

BACKGROUND: Even with intracoronary imaging-guided stent optimisation, suboptimal haemodynamic outcomes post-percutaneous coronary intervention (PCI) can be related to residual lesions in non-stented segments. Preprocedural assessment of pathophysiological coronary artery disease (CAD) patterns could help predict the physiological response to PCI. AIMS: The aim of this study was to assess the relationship between preprocedural pathophysiological haemodynamic patterns and intracoronary imaging findings, as well as their association with physiological outcomes immediately post-PCI. METHODS: Data from 206 patients with chronic coronary syndrome enrolled in the ASET-JAPAN study were analysed. Pathophysiological CAD patterns were characterised using Murray law-based quantitative flow ratio (µQFR)-derived indices acquired from pre-PCI angiograms. The diffuseness of CAD was defined by the pullback pressure gradient (PPG) index. Intracoronary imaging in stented segments after stent optimisation was also analysed. RESULTS: In the multivariable analysis, diffuse disease - defined by the pre-PCI µQFR-PPG index - was an independent factor for predicting a post-PCI µQFR <0.91 (per 0.1 decrease of PPG index, odds ratio 1.57, 95% confidence interval: 1.07-2.34; p=0.022), whereas the stent expansion index (EI) was not associated with a suboptimal post-PCI µQFR. Among vessels with an EI ≥80% and post-PCI µQFR <0.91, 84.0% of those vessels had a diffuse pattern preprocedure. There was no significant difference in EI between vessels with diffuse disease and those with focal disease. The average plaque burden in the stented segment was significantly larger in vessels with a preprocedural diffuse CAD pattern. CONCLUSIONS: A physiological diffuse pattern preprocedure was an independent factor in predicting unfavourable immediate haemodynamic outcomes post-PCI, even after stent optimisation using intracoronary imaging. Preprocedural assessment of CAD patterns could identify patients who are likely to exhibit superior immediate haemodynamic outcomes following PCI.

Can Machine Learning Aid the Selection of Percutaneous vs Surgical Revascularization?

BACKGROUND: In patients with 3-vessel coronary artery disease (CAD) and/or left main CAD, individual risk prediction plays a key role in deciding between percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG). OBJECTIVES: The aim of this study was to assess whether these individualized revascularization decisions can be improved by applying machine learning (ML) algorithms and integrating clinical, biological, and anatomical factors. METHODS: In the SYNTAX (Synergy between PCI with Taxus and Cardiac Surgery) study, ML algorithms (Lasso regression, gradient boosting) were used to develop a prognostic index for 5-year death, which was combined, in the second stage, with assigned treatment (PCI or CABG) and prespecified effect-modifiers: disease type (3-vessel or left main CAD) and anatomical SYNTAX score. The model's discriminative ability to predict the risk of 5-year death and treatment benefit between PCI and CABG was cross-validated in the SYNTAX trial (n = 1,800) and externally validated in the CREDO-Kyoto (Coronary REvascularization Demonstrating Outcome Study in Kyoto) registry (n = 7,362), and then compared with the original SYNTAX score II 2020 (SSII-2020). RESULTS: The hybrid gradient boosting model performed best for predicting 5-year all-cause death with C-indexes of 0.78 (95% CI: 0.75-0.81) in cross-validation and 0.77 (95% CI: 0.76-0.79) in external validation. The ML models discriminated 5-year mortality better than the SSII-2020 in the external validation cohort and identified heterogeneity in the treatment benefit of CABG vs PCI. CONCLUSIONS: An ML-based approach for identifying individuals who benefit from CABG or PCI is feasible and effective. Implementation of this model in health care systems-trained to collect large numbers of parameters-may harmonize decision making globally. (Synergy Between PCI With TAXUS and Cardiac Surgery: SYNTAX Extended Survival [SYNTAXES]; NCT03417050; SYNTAX Study: TAXUS Drug-Eluting Stent Versus Coronary Artery Bypass Surgery for the Treatment of Narrowed Arteries; NCT00114972).

Inter- and intra-observer reproducibility of CT-Leaman score by an independent core lab.

To assess the reproducibility of CT-based Leaman score (CT-LeSc). CT-LeSc can non-invasively quantify total coronary atherosclerotic burden and is an independent long-term predictor of cardiac events. Its calculation however relies on the subjective assessment of lesions using coronary computed tomography angiography and therefore is subject to intra- and inter-observer variability. Inter-observer reproducibility was assessed by calculating the CT-LeSc in 50 patients randomly selected from the SYNTAX III REVOLUTION and ABSORB trials by two separate teams, each made up of two cardiologists, who reported results by consensus. For intra-observer reproducibility, the CT-LeSc was calculated in same 50 patients on two occasions eight weeks apart, by the same team of two cardiologists. The level of agreement was measured by the weighted kappa statistic, with intra- and inter-observer variability used to evaluate the CT-LeSc's reproducibility. The variables evaluated by weighted kappa statistics were total number of lesions; number of calcified lesions; number of non-calcified lesions; number of mixed lesions; number of obstructive lesions; number of non-obstructive lesions; and the total CT-LeSc in increments of ten and five. During assessment of inter-observer variability the mean ± standard deviation (SD) CT-LeSc calculated by the first and second team was 15.36 ± 5.57 versus 15.24 ± 5.16. The mean of the differences (precision) was 0.97, with a SD (accuracy) 1.17. The inter-observer variability was lowest for Leaman score in increments of five (weighted kappa 0.93), and highest for the total number of calcified lesions (weighted kappa 0.66). During assessment of intra-observer variability, the mean ± SD CT-LeSc were 16.61 ± 5.28 versus 16.82 ± 5.55. The mean ± SD of the differences was 1.28 ± 1.02. The intra-observer variability was the lowest for Leaman score in increments of five (weighted kappa 0.93), and the highest for the total number of lesions and calcified lesions (weighted kappa 0.65). CT-LeSc has substantial to near-perfect agreement for reproducibility.

Glagov revisited: coronary artery disease phenotype on non-invasive imaging provides rationale for implementing preventive pharmacotherapy-a case report.

Background: Glagov et al. showed that no reduction in vessel lumen occurred until the atherosclerotic plaque burden exceeded 40% of the vessel area. Most major adverse cardiac events occurring in the first 4 years after a myocardial infarction arise from untreated angiographically mild, non-flow-limiting lesions at the time of the index event. We report how computed tomography (CT) coronary angiography (CCTA) can be used to non-invasively risk stratify a patient with non-obstructive coronary artery disease (CAD) and guide further management. Case summary: A 69-year-old non-smoking female with hypertension, dyslipidaemia, and hypothyroidism presented with atypical chest pain. Electrocardiogram and left ventricular ejection fraction were normal. Her lipidic profile was normal. CCTA showed a lipid-rich plaque with very low attenuation (<30 HU) in the left main stem (LMS) extending into the proximal left anterior descending (LAD) and in the mid LAD artery. The maximum plaque burden in the LMS was 67% with a remodelling index of 1.375, and an area stenosis of 22%. Tissue characterization showed a lipid-rich plaque with a thin fibrous cap. The perivascular fat attenuation index (FAI) in the proximal LAD was suggestive of (-69 HU) inflamed perivascular fat. Shear stress analysis of the LMS plaque showed normal wall shear stress (WSS); however, the axial plaque stress was high. Her medications were intensified to rosuvastatin 20 mg once daily (OD) and ezetimibe 10 mg OD. The patient remained asymptomatic at 6 months follow-up. Discussion: Our case exemplifies the value of CCTA as a diagnostic 'one-stop shop' (CCTA, finite element analysis, computed tomographic density [CTD], tissue characterization analysis, FAI analysis, WSS and wall strain, and etc.) when stratifying a patient with non-obstructive CAD. With further development of novel potent anti-lipidaemic and anti-inflammatory drugs, non-obstructive lesions with adverse plaque and haemodynamic parameters will have the opportunity to be treated with additional preventive pharmacological therapy.