Comparison of dual-bolus versus dual-sequence techniques for determining myocardial blood flow and myocardial perfusion reserve by cardiac magnetic resonance stress perfusion: From the Automated Quantitative analysis of myocardial perfusion cardiac Magnetic Resonance Consortium.

BACKGROUND: Quantitative stress cardiac magnetic resonance (CMR) can be performed using the dual-sequence (DS) technique or dual-bolus (DB) method. It is unknown if DS and DB produce similar results for myocardial blood flow (MBF) and myocardial perfusion reserve (MPR). The study objective is to investigate if there are any differences between DB- and DS-derived MBF and MPR. METHODS: Retrospective observational study with 168 patients who underwent stress CMR. DB and DS methods were simultaneously performed on each patient on the same day. Global and segmental stress MBF and rest MBF values were collected. RESULTS: Using Bland-Altman analysis, segmental and global stress MBF values were higher in DB than DS (0.22 ± 0.60 mL/g/min, p < 0.001 and 0.20 ± 0.48 mL/g/min, p = 0.005, respectively) with strong correlation (r = 0.81, p < 0.001 for segmental and r = 0.82, p < 0.001 for global). In rest MBF, segmental and global DB values were higher than by DS (0.15 ± 0.51 mL/g/min, p < 0.001 and 0.14 ± 0.36 mL/g/min, p = 0.011, respectively) with strong correlation (r = 0.81, p < 0.001 and r = 0.77, p < 0.001). Mean difference between MPR by DB and DS was -0.02 ± 0.68 mL/g/min (p = 0.758) for segmental values and -0.01 ± 0.49 mL/g/min (p = 0.773) for global values. MPR values correlated strongly as well in both segmental and global, both (r = 0.74, p < 0.001) and (r = 0.75, p < 0.001), respectively. CONCLUSION: There is a very good correlation between DB- and DS-derived MBF and MPR values. However, there are significant differences between DB- and DS-derived global stress and rest MBF. While MPR values did not show statistically significant differences between DB and DS methods.

Multi-Omics Signatures Link to Ticagrelor Effects on Vascular Function in Patients With Acute Coronary Syndrome.

BACKGROUND: Long-term antiplatelet agents including the potent P2Y12 antagonist ticagrelor are indicated in patients with a previous history of acute coronary syndrome. We sought to compare the effect of ticagrelor with that of aspirin monotherapy on vascular endothelial function in patients with prior acute coronary syndrome. METHODS: This was a prospective, single center, parallel group, investigator-blinded randomized controlled trial. We randomized 200 patients on long-term aspirin monotherapy with prior acute coronary syndrome in a 1:1 fashion to receive ticagrelor 60 mg BD (n=100) or aspirin 100 mg OD (n=100). The primary end point was change from baseline in brachial artery flow-mediated dilation at 12 weeks. Secondary end points were changes to platelet activation marker (CD41_62p) and endothelial progenitor cell (CD34/133) count measured by flow cytometry, plasma level of adenosine, IL-6 (interleukin-6) and EGF (epidermal growth factor), and multi-omics profiling at 12 weeks. RESULTS: After 12 weeks, brachial flow-mediated dilation was significantly increased in the ticagrelor group compared with the aspirin group (ticagrelor: 3.48±3.48% versus aspirin: -1.26±2.85%, treatment effect 4.73 [95% CI, 3.85-5.62], P<0.001). Nevertheless ticagrelor treatment for 12 weeks had no significant effect on platelet activation markers, circulating endothelial progenitor cell count or plasma level of adenosine, IL-6, and EGF (all P>0.05). Multi-omics pathway assessment revealed that changes in the metabolism and biosynthesis of amino acids (cysteine and methionine metabolism; phenylalanine, tyrosine, and tryptophan biosynthesis) and phospholipids (glycerophosphoethanolamines and glycerophosphoserines) were associated with improved brachial artery flow-mediated dilation in the ticagrelor group. CONCLUSIONS: In patients with prior acute coronary syndrome, ticagrelor 60 mg BD monotherapy significantly improved brachial flow-mediated dilation compared with aspirin monotherapy and was associated with significant changes in metabolomic and lipidomic signatures. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT03881943.

Clinical outcomes according to lesion complexity in high bleeding risk patients treated with 1-month dual antiplatelet therapy following PCI: Analysis from the Onyx ONE clear study.

OBJECTIVES: To compare clinical outcomes in high bleeding risk (HBR) patients with and without complex percutaneous coronary intervention (PCI) treated with Resolute Onyx zotarolimus-eluting stents (ZES) after 1-month dual antiplatelet therapy (DAPT). BACKGROUND: PCI with 1-month DAPT has been demonstrated to be safe in HBR patients treated with Resolute Onyx ZES. Whether these outcomes are consistent in patients with complex lesions is uncertain. METHODS: Among HBR patients who were event-free 1 month after PCI with ZES and treated thereafter with single antiplatelet therapy (SAPT), the clinical outcomes between 1 month and 1 year were compared after complex PCI (3 vessels treated, ≥ 3 lesions treated, total stent length > 60 mm, bifurcation with ≥ 2 stents implanted, atherectomy, or left main, surgical bypass graft or chronic total occlusion PCI) versus noncomplex PCI. Propensity score adjustment was performed to adjust for baseline differences among complex and noncomplex patients. RESULTS: Complex patients (N = 401, 26.6% of total) had a higher prevalence of hyperlipidemia, diabetes mellitus and previous myocardial infarction (MI). Between 1 month and 1 year, rates of MI (7.1% vs. 4.0%, p = 0.02) and cardiac death/MI (9.3% vs. 6.1%, p = 0.04) were higher among complex versus noncomplex patients, although stent thrombosis rates were similar. After adjustment for baseline characteristics, differences in outcomes were no longer significant between groups. CONCLUSIONS: Higher rates of ischemic outcomes in complex PCI patients were largely explained by baseline clinical differences, rather than lesion complexity, among HBR patients treated with 1-month DAPT following PCI with Resolute Onyx ZES.

Impact of coronavirus disease 2019 (COVID-19) outbreak on outcome of myocardial infarction in Hong Kong, China.

OBJECTIVE: To determine whether COVID-19 may adversely affect outcome of myocardial infarction (MI) patients in Hong Kong, China. BACKGROUND: The COVID-19 pandemic has infected thousands of people and placed enormous stress on healthcare system. Apart from being an infectious disease, it may affect human behavior and healthcare resource allocation which potentially cause treatment delay in MI. METHODS: This was a single center cross-sectional observational study. From November 1, 2019 to March 31, 2020, we compared outcome of patients admitted for acute ST-elevation MI (STEMI) and non-ST elevation MI (NSTEMI) before (group 1) and after (group 2) January 25, 2020 which was the date when Hong Kong hospitals launched emergency response measures to combat COVID-19. RESULTS: There was a reduction in daily emergency room attendance since January 25, 2020 (group 1,327/day vs. group 2,231/day) and 149 patients with diagnosis of MI were included into analysis (group 1 N = 85 vs. group 2 N = 64). For STEMI, patients in group 2 tended to have longer symptom-to-first medical contact time and more presented out of revascularization window (group 1 27.8 vs. group 2 33%). The primary composite outcome of in-hospital death, cardiogenic shock, sustained ventricular tachycardia or fibrillation (VT/VF) and use of mechanical circulatory support (MCS) was significantly worse in group 2 (14.1 vs. 29.7%, p = .02). CONCLUSIONS: More MI patients during COVID-19 outbreak had complicated in-hospital course and worse outcomes. Besides direct infectious complications, cardiology community has to acknowledge the indirect effect of communicable disease on our patients and system of care.

Thrombolysis in Myocardial Infarction Risk Score for Secondary Prevention of Recurrent Cardiovascular Events in a Real-World Cohort of Post-Acute Myocardial Infarction Patients.

BACKGROUND: Patients who survive myocardial infarction (MI) are at risk of recurrent cardiovascular (CV) events. This study stratified post-MI patients for risk of recurrent CV events using the Thrombolysis in Myocardial Infarction (TIMI) Risk Score for Secondary Prevention (TRS 2°P). Methods and Results: This was an observational study that applied TRS 2°P to a consecutive cohort of post-MI patients. The primary outcome was a composite endpoint of CV death, non-fatal MI, and non-fatal ischemic stroke. A total of 1,688 post-MI patients (70.3±13.6 years; male, 63.1%) were enrolled. After a mean follow-up of 41.5±34.4 months, 405 patients (24.0%) had developed a primary outcome (9.3%/year) consisting of 278 CV deaths, 134 non-fatal MI, and 33 non-fatal strokes. TRS 2°P was strongly associated with the primary outcome. The annual incidence of primary composite endpoint for patients with TRS 2°P 0 was 1.0%, and increased progressively to 39.9% for those with TRS 2°P ≥6 (HR, 27.6; 95% CI: 9.87-77.39, P<0.001). The diagnostic sensitivity of TRS 2°P for the primary composite endpoint was 76.3% (95% CI: 72.1-80.5%). Similar associations were also observed between TRS 2°P and CV death and non-fatal MI, but not non-fatal ischemic stroke. CONCLUSIONS: TRS 2°P reliably stratified post-MI patients for risk of future CV events.

Coronary Vasospasm Presenting in a Catastrophic Way.

Coronary artery vasospasm is an under-recognized yet fatal condition that can manifest as sudden cardiac arrest. A 51-year-old man presented with out-of-hospital cardiac arrest due to ventricular fibrillation during exercise. Coronary angiogram showed severe disease at ostial left main coronary artery and left anterior descending artery (LAD), that was not present anymore on repeated angiography and intravascular ultrasound assessment. Cardiac magnetic resonance demonstrated evidence of prior myocardial infarction in the LAD territory. Acetylcholine challenge test was performed that induced severe left main coronary artery and LAD spasm. Coronary artery vasospasm has contributed to a significant proportion of patients presenting with coronary artery disease. Establishing the correct diagnosis is detrimental to future management of patients. This case highlighted a multimodality approach in the diagnosis of coronary vasospasm.

Challenges in management of ST elevation myocardial infarction during COVID-19 pandemic.

The coronavirus disease-2019 (COVID-19) pandemic has brought unprecedented changes to our world and health-care system. Its high virulence and infectiousness directly infect people's respiratory system and indirectly disrupt our health-care infrastructure. In particular, ST elevation myocardial infarction (STEMI) is a clinical emergency emphasizes on the establishment of care system to minimize delay to reperfusion. As such, the impact of COVID-19 on STEMI care, ranging from disease severity, patient delay, diagnostic difficulty, triage to selection of reperfusion strategy and postoperative care, is immense. Importantly, not only we have to save our patients, but we must also need to protect all health-care workers and prevent environmental contamination. Otherwise, in-hospital transmission can quickly evolve into nosocomial outbreak with staff infection and quarantine which lead to health-care system collapse. In this article, we will discuss the challenges in various aspects of STEMI management during COVID-19, as well as the mitigation measures we can take to optimize outcome and our future.

Protocol, rationale and design of DAbigatran for Stroke PreVention In Atrial Fibrillation in MoDerate or Severe Mitral Stenosis (DAVID-MS): a randomised, open-label study.

INTRODUCTION: Current international guidelines recommend non-vitamin K oral anticoagulants (NOACs) for stroke prevention among patients with non-valvular atrial fibrillation (AF) at significant ischaemic stroke risk given the superior safety and comparable efficacy of NOACs over warfarin. Nonetheless, the safety and effectiveness of NOACs have not been evaluated in patients with AF with underlying moderate or severe mitral stenosis (MS), hence the recommended stroke prevention strategy remains warfarin therapy. METHOD AND ANALYSIS: MS remains disproportionately prevalent in Asian countries compared with the developed countries. This prospective, randomised, open-label trial with blinded endpoint adjudication aims to evaluate the safety and efficacy of dabigatran for stroke prevention in AF patients with moderate or severe MS. Patients with AF aged ≥18 years with moderate or severe MS not planned for valvular intervention in the coming 12 months will be randomised in a 1:1 ratio to receive dabigatran 110 mg or 150 mg two times per day or warfarin with international normalised ratio 2-3 in an open-label design. Patients with estimated creatinine clearance <30 mL/min, or with a concomitant indication for antiplatelet therapy will be excluded. The primary outcome is a composite of stroke and systemic embolism. Secondary outcomes are ischaemic stroke, systemic embolism, haemorrhagic stroke, intracranial haemorrhage, major bleeding and death. The estimated required sample size is approximately 686 participants. ETHICS AND DISSEMINATION: The study protocol has been approved by the Institutional Review Board of the University of Hong Kong and Hong Kong West Cluster, Hospital Authority, Hong Kong for Fung Yiu King Hospital, Grantham Hospital, Queen Mary Hospital and Tung Wah Hospital in Hong Kong. Results will be published in peer-reviewed journals. TRIAL REGISTRATION NUMBER: ClinicalTrials.gov Registry (NCT04045093); pre-results.