Evaluating artificial intelligence-driven stress echocardiography analysis system (EASE study): A mixed method study.

INTRODUCTION: The use and value of artificial intelligence (AI)-driven tools and techniques are under investigation in detecting coronary artery disease (CAD). EchoGo Pro is a patented AI-driven stress echocardiography analysis system produced by Ultromics Ltd. (henceforth Ultromics) to support clinicians in detecting cardiac ischaemia and potential CAD. This manuscript presents the research protocol for a field study to independently evaluate the accuracy, acceptability, implementation barriers, users' experience and willingness to pay, cost-effectiveness and value of EchoGo Pro. METHODS AND ANALYSIS: The 'Evaluating AI-driven stress echocardiography analysis system' (EASE) study is a mixed-method evaluation, which will be conducted in five work packages (WPs). In WP1, we will examine the diagnostic accuracy by comparing test reports generated by EchoGo Pro and three manual raters. In WP2, we will focus on interviewing clinicians, innovation/transformation staff, and patients within the National Health Service (NHS), and staff within Ultromics, to assess the acceptability of this technology. In this WP, we will determine convergence and divergence between EchoGo Pro recommendations and cardiologists' interpretations and will assess what profile of cases is linked with convergence and divergence between EchoGo Pro recommendations and cardiologists' interpretations and how these link to outcomes. In WP4, we will conduct a quantitative cross-sectional survey of trust in AI tools applied to cardiac care settings among clinicians, healthcare commissioners and the general public. Lastly, in WP5, we will estimate the cost of deploying the EchoGo Pro technology, cost-effectiveness and willingness to pay cardiologists, healthcare commissioners and the general public. The results of this evaluation will support evidence-informed decision-making around the widespread adoption of EchoGo Pro and similar technologies in the NHS and other health systems. ETHICS APPROVAL AND DISSEMINATION: This research has been approved by the NHS Health Research Authority (IRAS No: 315284) and the London South Bank University Ethics Panel (ETH2223-0164). Alongside journal publications, we will disseminate study methods and findings in conferences, seminars and social media. We will produce additional outputs in appropriate forms, for example, research summaries and policy briefs, for diverse audiences in NHS.

Early Intervention in Patients With Asymptomatic Severe Aortic Stenosis and Myocardial Fibrosis: The EVOLVED Randomized Clinical Trial.

Importance: Development of myocardial fibrosis in patients with aortic stenosis precedes left ventricular decompensation and is associated with an adverse long-term prognosis. Objective: To investigate whether early valve intervention reduced the incidence of all-cause death or unplanned aortic stenosis-related hospitalization in asymptomatic patients with severe aortic stenosis and myocardial fibrosis. Design, Setting, and Participants: This prospective, randomized, open-label, masked end point trial was conducted between August 2017 and October 2022 at 24 cardiac centers across the UK and Australia. Asymptomatic patients with severe aortic stenosis and myocardial fibrosis were included. The final date of follow-up was July 26, 2024. Intervention: Early valve intervention with transcatheter or surgical aortic valve replacement or guideline-directed conservative management. Main Outcomes and Measures: The primary outcome was a composite of all-cause death or unplanned aortic stenosis-related hospitalization in a time-to-first-event intention-to-treat analysis. There were 9 secondary outcomes, including the components of the primary outcome and symptom status at 12 months. Results: The trial enrolled 224 eligible patients (mean [SD] age, 73 [9] years; 63 women [28%]; mean [SD] aortic valve peak velocity of 4.3 [0.5] m/s) of the originally planned sample size of 356 patients. The primary end point occurred in 20 of 113 patients (18%) in the early intervention group and 25 of 111 patients (23%) in the guideline-directed conservative management group (hazard ratio, 0.79 [95% CI, 0.44-1.43]; P = .44; between-group difference, -4.82% [95% CI, -15.31% to 5.66%]). Of 9 prespecified secondary end points, 7 showed no significant difference. All-cause death occurred in 16 of 113 patients (14%) in the early intervention group and 14 of 111 (13%) in the guideline-directed group (hazard ratio, 1.22 [95% CI, 0.59-2.51]) and unplanned aortic stenosis hospitalization occurred in 7 of 113 patients (6%) and 19 of 111 patients (17%), respectively (hazard ratio, 0.37 [95% CI, 0.16-0.88]). Early intervention was associated with a lower 12-month rate of New York Heart Association class II-IV symptoms than guideline-directed conservative management (21 [19.7%] vs 39 [37.9%]; odds ratio, 0.37 [95% CI, 0.20-0.70]). Conclusions and Relevance: In asymptomatic patients with severe aortic stenosis and myocardial fibrosis, early aortic valve intervention had no demonstrable effect on all-cause death or unplanned aortic stenosis-related hospitalization. The trial had a wide 95% CI around the primary end point, with further research needed to confirm these findings. Trial Registration: ClinicalTrials.gov Identifier: NCT03094143.

Considering alternatives to transcatheter heart valves for managing patients with severe aortic valve stenosis.

INTRODUCTION: Transcatheter aortic valve implantation (TAVI) is becoming the standard of care for severe symptomatic aortic stenosis (AS). Yet, some patients with AS are not indicated/eligible for TAVI. Several noninvasive, catheter-based or surgical alternatives exist, and other therapeutic options are emerging. AREAS COVERED: This review provides an overview of non-TAVI options for severe AS. Non-invasive, transcatheter, and alternative surgical strategies are discussed, emphasizing their backgrounds, techniques, and outcomes. EXPERT OPINION: Alternative therapies to TAVI, whether device-based or non-device-based, continue to evolve or emerge and provide either alternative treatments or a bridge to TAVI, for patients not meeting indications for, or having contraindications to TAVI.Although TAVI and SAVR are the current dominant therapies, there are still some patients that could benefit in the future from other alternatives.Data on alternative options for such patients are scarce. Many advantages and disadvantages arise when selecting a specific treatment strategy for individual patients.Head-to-head comparison studies could guide physicians toward better patient selection and procedural planning. Awareness of therapeutic options, indications, techniques, and outcomes should enable heart teams to achieve optimized patient selection. Furthermore, it can increase the use of these alternatives to optimize the management of AS among different patient populations.

The Use and Efficacy of FFR-CT: Real-World Multicenter Audit of Clinical Data With Cost Analysis.

BACKGROUND: Fractional flow reserve-computed tomography (FFR-CT) is endorsed by UK and U.S. chest pain guidelines, but its clinical effectiveness and cost benefit in real-world practice are unknown. OBJECTIVES: The purpose of this study was to audit the use of FFR-CT in clinical practice against England's National Institute for Health and Care Excellence guidance and assess its diagnostic accuracy and cost. METHODS: A multicenter audit was undertaken covering the 3 years when FFR-CT was centrally funded in England. For coronary computed tomographic angiograms (CCTAs) submitted for FFR-CT analysis, centers provided data on symptoms, CCTA and FFR-CT findings, and subsequent management. Audit standards included using FFR-CT only in patients with stable chest pain and equivocal stenosis (50%-69%). Diagnostic accuracy was evaluated against invasive FFR, when performed. Follow-up for nonfatal myocardial infarction and all-cause mortality was undertaken. The cost of an FFR-CT strategy was compared to alternative stress imaging pathways using cost analysis modeling. RESULTS: A total of 2,298 CCTAs from 12 centers underwent FFR-CT analysis. Stable chest pain was the main symptom in 77%, and 40% had equivocal stenosis. Positive and negative predictive values of FFR-CT were 49% and 76%, respectively. A total of 46 events (2%) occurred over a mean follow-up period of 17 months; FFR-CT (cutoff: 0.80) was not predictive. The FFR-CT strategy costs £2,102 per patient compared with an average of £1,411 for stress imaging. CONCLUSIONS: In clinical practice, the National Institute for Health and Care Excellence criteria for using FFR-CT were met in three-fourths of patients for symptoms and 40% for stenosis. FFR-CT had a low positive predictive value, making its use potentially more expensive than conventional stress imaging strategies.

Cardiovascular Magnetic Resonance Imaging in Familial Dilated Cardiomyopathy.

Dilated cardiomyopathy (DCM) is a common cause of non-ischaemic heart failure, conferring high morbidity and mortality, including sudden cardiac death due to systolic dysfunction or arrhythmic sudden death. Within the DCM cohort exists a group of patients with familial disease. In this article we review the pathophysiology and cardiac imaging findings of familial DCM, with specific attention to known disease subtypes. The role of advanced cardiac imaging cardiovascular magnetic resonance is still accumulating, and there remains much to be elucidated. We discuss its potential clinical roles as currently known, with respect to diagnostic utility and risk stratification. Advances in such risk stratification may help target pharmacological and device therapies to those at highest risk.

Left ventricular T1-mapping in diastole versus systole in patients with mitral regurgitation.

Cardiovascular magnetic resonance T1-mapping enables myocardial tissue characterisation, and is capable of quantifying both intracellular and extracellular volume. T1-mapping is conventionally performed in diastole, however, we hypothesised that systolic readout would reduce variability due to a reduction in myocardial blood volume. This study investigated whether T1-mapping in systole alters T1 values compared to diastole and whether reproducibility alters in atrial fibrillation compared to sinus rhythm. We prospectively identified 103 consecutive patients recruited to the Mitral FINDER study who had T1 mapping in systole and diastole. These patients had moderate or severe mitral regurgitation and a high incidence of ventricular dilatation and atrial fibrillation. T1, ECV and goodness-of-fit (R2) values of the T1 times were calculated offline using Circle cvi42 and in house-developed software. Systolic T1 mapping was associated with fewer myocardial segments being affected by artefact compared to diastolic T1 mapping [217/2472 (9%) vs 515/2472 (21%)]. Mean native T1 values were not significantly different when measured in systole and diastole (985 ± 26 ms vs 988 ± 29 respectively; p = 0.061) and mean post-contrast values showed similar good agreement (462 ± 32 ms vs 459 ± 33 respectively, p = 0.052). No clinically significant differences in ECV, native T1 and post-contrast T1 were identified between diastolic and systolic T1 maps in males versus females, or in patients with permanent atrial fibrillation versus sinus rhythm. A statistically significant improvement in R2 value was observed with systolic over diastolic T1 mapping in all analysed maps (n = 411) (96.2 ± 1.4% vs 96.0 ± 1.4%; p < 0.001) and in subgroup analyses [Sinus rhythm: 96.1 ± 1.4 vs 96.3 ± 1.4 (n = 327); p < 0.001. AF: 95.5 ± 1.3 vs 95.9 ± 1.2 (n = 80); p < 0.001] [Males: 95.8 ± 1.4 vs 96.1 ± 1.3 (n = 264); p < 0.001; Females: 96.2 ± 1.3 vs 96.4 ± 1.4 (n = 143); p = 0.009]. In conclusion, myocardial T1 mapping is associated with similar T1 and ECV values in systole and diastole. Furthermore, systolic acquisition is less prone to gating artefact in arrhythmia.

Valvular Cardiomyopathy: The Value of Cardiovascular Magnetic Resonance Imaging.

Cardiovascular magnetic resonance (CMR) imaging has had a vast impact on the understanding of a wide range of disease processes and pathophysiological mechanisms. More recently, it has contributed significantly to the diagnosis and risk stratification of patients with valvular heart disease. With its increasing use, CMR allows for a detailed, reproducible, qualitative, and quantitative evaluation of left ventricular volumes and mass, thereby enabling assessment of the haemodynamic impact of a valvular lesion upon the myocardium. Postprocessing of the routinely acquired images with feature tracking CMR methodology can give invaluable information about myocardial deformation and strain parameters that suggest subclinical ventricular impairment that remains undetected by conventional measures such as the ejection fraction (EF). T1 mapping and late gadolinium enhancement (LGE) imaging provide deep myocardial tissue characterisation that is changing the approach towards risk stratification of patients as an increasing body of evidence suggests that the presence of fibrosis is related to adverse events and prognosis. This review summarises the current evidence regarding the utility of CMR in the left ventricular assessment of patients with aortic stenosis or mitral regurgitation and its value in diagnosis, risk stratification, and management.

Herceptin-Mediated Cardiotoxicity: Assessment by Cardiovascular Magnetic Resonance.

Herceptin (trastuzumab) is a recombinant, humanized, monoclonal antibody that targets the human epidermal growth factor receptor 2 (HER2) and is used in the treatment of HER2-positive breast and gastric cancers. However, it carries a risk of cardiotoxicity, manifesting as left ventricular (LV) systolic dysfunction, conventionally assessed for by transthoracic echocardiography. Clinical surveillance of cardiac function and discontinuation of trastuzumab at an early stage of LV systolic dysfunction allow for the timely initiation of heart failure drug therapies that can result in the rapid recovery of cardiac function in most patients. Often considered the reference standard for the noninvasive assessment of cardiac volume and function, cardiac magnetic resonance (CMR) imaging has superior reproducibility and accuracy compared to other noninvasive imaging modalities. However, due to limited availability, it is not routinely used in the serial assessment of cardiac function in patients receiving trastuzumab. In this article, we review the diagnostic and prognostic role of CMR in trastuzumab-mediated cardiotoxicity.

A Longitudinal Study of Mitral Regurgitation Detected after Acute Myocardial Infarction.

BACKGROUND: Mitral regurgitation (MR) is common following myocardial infarction (MI). However, the subsequent trajectory of MR, and its impact on long-term outcomes are not well understood. This study aimed to examine the change in MR severity and associated clinical outcomes following MI. METHODS: Records of patients admitted to a single centre between 2016 and 2017 with acute MI treated by percutaneous coronary intervention (PCI) were retrospectively examined. RESULTS: 294/1000 consecutive patients had MR on baseline (pre-discharge) transthoracic echocardiography (TTE), of whom 126 (mean age: 70.9 ± 11.4 years) had at least one follow-up TTE. At baseline, most patients had mild MR (n = 94; 75%), with n = 30 (24%) moderate and n = 2 (2%) severe MR. Significant improvement in MR was observed at the first follow-up TTE (median 9 months from baseline; interquartile range: 3-23), with 36% having reduced severity, compared to 10% having increased MR severity (p < 0.001). Predictors of worsening MR included older age (mean: 75.2 vs. 66.7 years; p = 0.003) and lower creatinine clearance (mean: 60 vs. 81 mL/min, p = 0.015). Change in MR severity was significantly associated with prognosis: 16% with improving MR reached the composite endpoint of death or heart failure hospitalisation at 5 years, versus 44% (p = 0.004) with no change, and 59% (p < 0.001) with worsening MR. CONCLUSIONS: Of patients with follow-up TTE after MI, MR severity improved from baseline in approximately one-third, was stable in around half, with the remainder having worsening MR. Patients with persistent or worsening MR had worse clinical outcomes than those with improving MR.

Utility of Non-invasive Cardiac Imaging Assessment in Coronavirus Disease 2019.

Coronavirus disease 2019 (COVID-19) was initially regarded as a disease of the lungs, which manifests as an acute respiratory illness and pneumonia, although more recently cardiac complications have been well-characterised. Serological cardiac biomarkers have been used to define acute myocardial injury, with significant elevation of high-sensitivity cardiac troponin (hs-cTn) associated with poor prognosis. Accordingly, 20-25% patients with acute myocardial injury (as defined by an elevated hs-cTn greater than the 99th percentile) have clinical signs of heart failure and increased mortality. An important outstanding clinical question is how best to determine the extent and nature of cardiac involvement in COVID-19. Non-invasive cardiac imaging has a well-established role in assessing cardiac structure and function in a wide range of cardiac diseases. It offers the potential to differentiate between direct and indirect COVID-19 effects upon the heart, providing incremental diagnostic and prognostic utility beyond the information yielded by elevated cardiac biomarkers in isolation. This review will focus on the non-invasive imaging assessment of cardiac involvement in COVID-19.

Impact of Right Ventricular Dysfunction on Mortality in Patients Hospitalized With COVID-19, According to Race.

BACKGROUND: Epidemiologic studies suggest that Black, Asian, and minority ethnic (BAME) patients may be at risk of worse outcomes from coronavirus disease-2019 (COVID-19), but the pathophysiological drivers for this association are unknown. This study sought to investigate the relationship between findings on echocardiography, mortality, and race in COVID-19 pneumonia. METHODS: This was a multicentre, retrospective, observational study including 164 adults (aged 61 ± 13 years; 78% male; 36% BAME) hospitalized with COVID-19 undergoing echocardiography between March 16 and May 9, 2020 at 3 days (interquartile range 2-5) from admission. The primary outcome was all-cause mortality. RESULTS: After a median follow-up of 31 days (interquartile range 14-42 days), 66 (40%) patients had died. The right ventricle was dilated in 62 (38%) patients, and 58 (35%) patients had right ventricular (RV) systolic dysfunction. Only 2 (1%) patients had left ventricular (LV) dilatation, and 133 (81%) had normal or hyperdynamic LV systolic function. Reduced tricuspid annulus planar systolic excursion was associated with elevated D-dimer (ρ = -0.18, P = 0.025) and high-sensitivity cardiac Troponin (ρ = -0.30, P < 0.0001). Reduced RV systolic function (hazard ratio 1.80; 95% confidence interval, 1.05-3.09; P = 0.032) was an independent predictor of all-cause mortality after adjustment for demographic and clinical risk factors. Comparing white and BAME individuals, there were no differences in echocardiography findings, biomarkers, or mortality. CONCLUSIONS: In patients hospitalized with COVID-19 pneumonia, reduced RV systolic function is prevalent and associated with all-cause mortality. There is, however, no racial variation in the early findings on echocardiography, biomarkers, or mortality.

CONTEXTE: Des études épidémiologiques suggèrent que les patients noirs, asiatiques et appartenant à des minorités ethniques (BAME) auraient un risque accru d'aggravation de la maladie à coronavirus 2019 (COVID-19), mais les facteurs physiopathologiques de cette association sont inconnus. Cette étude a cherché à étudier la relation entre les données d'échocardiographie, de mortalité, de l'origine ethnique avec la pneumonie associée à la COVID-19. MÉTHODES: Il s'agit d'une étude observationnelle rétrospective multicentrique portant sur 164 adultes (âgés de 61 ± 13 ans; 78 % d'hommes; 36 % de BAME) hospitalisés pour la COVID-19 et soumis à une échocardiographie entre le 16 mars et le 9 mai 2020, trois jours (écart interquartile 2-5) après leur admission. Le critère principal d'évaluation était la mortalité, toutes causes confondues. RÉSULTATS: Après un suivi médian de 31 jours (intervalle interquartile 14-42 jours), 66 (40 %) patients sont décédés. Le ventricule droit était dilaté chez 62 (38 %) des patients, et 58 (35 %) patients présentaient une dysfonction systolique du ventricule droit (VD). Seuls deux (1 %) patients présentaient une dilatation du ventricule gauche (VG), et 133 (81 %) avaient une fonction systolique VG normale ou en état hyperdynamique. Une réduction du déplacement systolique de l'anneau tricuspide a été associée à un taux de D-dimère élevé (ρ = -0,18, P = 0,025) et à une Troponine cardiaque de haute sensibilité (ρ = -0,30, P < 0,0001). Une fonction systolique VD réduite (rapport de risque de 1,80; intervalle de confiance à 95 %, 1,05-3,09 ; P = 0,032) était un facteur prédicteur indépendant pour la mortalité, toutes causes confondues, après ajustement pour les facteurs de risque démographiques et cliniques. En comparant les individus blancs et BAME, aucune différence n'a été constatée concernant les résultats d'échocardiographie, les biomarqueurs ou la mortalité. CONCLUSIONS: Chez les patients hospitalisés pour une pneumonie liée à la COVID-19, une réduction de la fonction systolique VD est apparue comme prévalente et associée à la mortalité, toutes causes confondues. Il n'y a cependant aucune influence de l'ethnicité en rapport avec les premiers résultats d'échocardiographie, des biomarqueurs ou de la mortalité.

Remodelling elective hospital services in the COVID-19 era - designing the new normal.

The provision of elective clinical services has decreased during the initial phase of the coronavirus disease 2019 (COVID-19) pandemic to enable hospitals to focus on acute illness. Any end to the pandemic through widespread vaccination, effective treatment or development of herd immunity may be years away. Until then, hospitals will need to resume treating other diseases while also attempting to eradicate transmission of COVID-19 within the healthcare setting. In this article we suggest six major themes which could affect the design and delivery of elective clinical services: hospital avoidance, separation of high- and low-risk groups, screening, maintenance of adequate infection control, and new ways of working.

Temporal Variability in Electrocardiographic Indices in Subjects With Brugada Patterns.

INTRODUCTION: Patients with Brugada electrocardiographic (ECG) patterns have differing levels of arrhythmic risk. We hypothesized that temporal variations in certain ECG markers may provide additional value for risk stratification. The present study evaluated the relationship between temporal variability of ECG markers and arrhythmic outcomes in patients with a Brugada pattern ECG. Comparisons were made between low-risk asymptomatic subjects versus high-risk symptomatic patients with a history of syncope, ventricular tachycardia (VT) or ventricular fibrillation (VF). METHODS: A total of 81 patients presenting with Brugada patterns were recruited. Serial ECGs and electronic health records from January 2004 to April 2019 were analyzed. Temporal variability of QRS interval, J point-Tpeak interval (JTp), Tpeak-Tend interval (Tp-e), and ST elevation (STe) in precordial leads V1-3, in addition to RR-interval from lead II, was assessed using standard deviation and difference between maximum and minimum values over the serial ECGs. RESULTS: Patients presenting with type 1 Brugada ECG pattern initially had significantly higher variability in JTp from lead V2 (SD: 33.5 ± 13.8 vs. 25.2 ± 11.5 ms, P = 0.009; max-min: 98.6 ± 46.2 vs. 78.3 ± 47.6 ms, P = 0.047) and ST elevation in lead V1 (0.117 ± 0.122 vs. 0.053 ± 0.030 mV; P = 0.004). Significantly higher variability in Tp-e interval measured from lead V3 was observed in the VT/VF group compared to the syncope and asymptomatic groups (SD: 20.5 ± 8.5 vs. 16.6 ± 7.3 and 14.7 ± 9.8 ms; P = 0.044; max-min: 70.2 ± 28.9 vs. 56.3 ± 29.0 and 43.5 ± 28.5 ms; P = 0.011). CONCLUSION: Temporal variability in ECG indices may provide additional value for risk stratification in patients with Brugada pattern.

Correction to: Restitution metrics in Brugada syndrome: a systematic review and meta-analysis.

The original version of this article unfortunately has a typo error. The name of the author "Kamalan Jeeveratnam" should be presented as "Kamalan Jeevaratnam" as shown above.

Restitution metrics in Brugada syndrome: a systematic review and meta-analysis.

BACKGROUND: Brugada syndrome (BrS) is an ion channelopathy that predisposes affected subjects to ventricular tachycardia/fibrillation (VT/VF) and sudden cardiac death. Restitution analysis has been examined in BrS patients but not all studies have reported significant differences between BrS patients and controls. Therefore, we conducted a systematic review and meta-analysis to investigate the different restitution indices used in BrS. METHODS: PubMed and Embase were searched until April 7, 2019, identifying 20 and 27 studies. RESULTS: A total of ten studies involving 178 BrS (mean age 38 years old, 63% male) and 102 controls (mean age 31 years old, 42% male) were included in this systematic review. Pacing was carried out at the right ventricular outflow tract (RVOT)/right ventricular apex (RPA) (n = 4), RPA (n = 4), or right atrium (RA) (n = 1). Basic cycle lengths of 400 (n = 4), 500 (n = 2), 600 (n = 6) and 750 ms (n = 1) were used. Recording methods include electrograms (n = 4), monophasic action potentials (n = 5), and electrocardiograms (n = 1). Signals were obtained from the RVOT (n = 8), RVA (n = 3), RA (n = 1), or the body surface (n = 1). The maximum restitution slope for endocardial repolarization at the RVOT was 0.87 for BrS patients (n = 5; 95% confidence interval [CI] 0.68-1.07) compared with 0.74 in control subjects (n = 4; 95% CI 0.42-1.06), with a significant mean difference of 0.40 (n = 4; 95% CI 0.11-0.69; P = 0.007). CONCLUSIONS: Steeper endocardial repolarization restitution slopes are found in BrS patients compared with controls at baseline. Restitution analysis can provide important information for risk stratification in BrS.

Cangrelor versus Ticagrelor in Patients Treated with Primary Percutaneous Coronary Intervention: Impact on Platelet Activity, Myocardial Microvascular Function and Infarct Size: A Randomized Controlled Trial.

BACKGROUND: Oral P2Y12 inhibitors take more than 2 hours to achieve full effect in healthy subjects and this action is further delayed in patients with acute myocardial infarction. Intravenous P2Y12 inhibition might lead to more timely and potent anti-platelet effect in the context of emergency primary angioplasty, improving myocardial recovery. OBJECTIVES: This article compares the efficacy of intravenous cangrelor versus ticagrelor in a ST-elevation myocardial infarction (STEMI) population treated with primary percutaneous coronary intervention (PPCI). MATERIALS AND METHODS: In an open-label, prospective, randomized controlled trial, 100 subjects with STEMI were assigned 1:1 to intravenous cangrelor or oral ticagrelor. The co-primary endpoints were platelet P2Y12 inhibition at infarct vessel balloon inflation time, 4 and 24 hours. Secondary endpoints included indices of coronary microcirculatory function: index of microvascular resistance (IMR), initial infarct size (troponin at 24 hours) and final infarct size at 12 weeks (cardiac magnetic resonance). Secondary endpoints included indices of coronary microcirculatory function (index of microvascular resistance [IMR]), initial infarct size (troponin at 24 hours), final infarct size at 12 weeks (cardiac magnetic resonance), corrected thrombolysis in myocardial infarction (TIMI) frame count, TIMI flow grade, myocardial perfusion grade, and ST-segment resolution (ClinicalTrials.gov NCT02733341). RESULTS: P2Y12 inhibition at first balloon inflation time was significantly greater in cangrelor-treated patients (cangrelor P2Y12 reaction unit [PRU] 145.2 ± 50.6 vs. ticagrelor 248.3 ± 55.1). There was no difference in mean PRU at 4 and 24 to 36 hours post-dosing. IMR, final infarct size, angiographic and electrocardiographic measures of reperfusion were all similar between groups. CONCLUSION: Cangrelor produces more potent P2Y12 inhibition at the time of first coronary balloon inflation time compared with ticagrelor. Despite this enhanced P2Y12 inhibition, coronary microvascular function and final infarct size did not differ between groups.