Publications by authors named "Mark Y Y Chan"

Bile acids are liver-derived signaling molecules that can be found in the brain, but their role there remains largely unknown. We found increased brain chenodeoxycholic acid (CDCA) in mice with absent 12α-hydroxylase (Cyp8b1), a bile acid synthesis enzyme. In these Cyp8b1, and in Wt mice administered CDCA, stroke infarct area was reduced.

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Background: The comparison of coronary computed tomography angiography plaques and perivascular adipose tissue (PVAT) between patients with acute myocardial infarction (AMI) posttreatment and patients with stable coronary artery disease is poorly understood. Our objective was to evaluate the differences in coronary computed tomography angiography-quantified plaque and PVAT characteristics in patients post-AMI and identify signs of residual inflammation.

Methods And Results: We analyzed 205 patients (age, 59.

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  • Variegin and its variant, ultravariegin (UV), have shown potential in early studies for improving blood clot inhibition without the bleeding risks associated with traditional drugs like heparin.
  • PEGylation, a technique that attaches PEG chains to the UV peptide, significantly enhances its circulation time and effectiveness, allowing for prolonged anticoagulant effects in animal models while maintaining its efficacy.
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  • Cardiovascular disease, especially ischemic heart disease, is increasing globally, and this study investigates the effects of sodium-glucose cotransporter 2 inhibitors (SGLT2i) on patients who have had a heart attack (post-AMI).
  • A systematic review analyzed eight clinical trials involving over 11,000 post-AMI patients and found that SGLT2i significantly reduced hospitalizations for heart failure and lowered NT-proBNP levels, indicating improved heart function.
  • However, there were no notable differences in all-cause or cardiovascular mortality, left ventricular ejection fraction, or blood sugar levels when comparing SGLT2i to placebo.
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  • Researchers studied 472 patients with left ventricular thrombus (LVT) to identify unique clinical profiles using cluster analysis.
  • They found two distinct groups: one made up of younger patients with fewer risk factors linked primarily to recent heart attacks, and another older group with more comorbidities related to ischemic cardiomyopathy.
  • The study revealed that the second group had a lower chance of LVT resolution and a higher risk of mortality, highlighting the importance of tailored treatment approaches for different patient profiles.
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Background: Left atrial (LA) fibrosis is a marker of atrial cardiomyopathy and has been reported to be associated with both atrial fibrillation and ischemic stroke. Elucidating this relationship is clinically important as LA fibrosis could serve as a surrogate biomarker of LA cardiomyopathy. The objective of this study is to investigate the association of LA fibrosis and embolic stroke of undetermined source (ESUS) using cardiac magnetic resonance imaging.

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Background And Aims: Endovascular thrombectomy (EVT) is the current standard of care for large vessel occlusion (LVO) acute ischemic stroke (AIS); however, up to two-thirds of EVT patients have poor functional outcomes despite successful reperfusion. Many radiological markers have been studied as predictive biomarkers for patient outcomes in AIS. This study seeks to determine which clinico-radiological factors are associated with outcomes of interest to aid selection of patients for EVT for LVO AIS.

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Background: Patients with migraines, particularly those with auras, may present with stroke. Atrial fibrillation is a known risk factor for stroke. With common pathophysiological factors between migraines and atrial fibrillation, we aimed to clarify the association between migraine and atrial fibrillation in this systematic review and meta-analysis.

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  • Metabolic syndrome (MetS) affects over one third of US adults and is linked to non-alcoholic fatty liver disease (NAFLD), which isn't currently included in its traditional diagnosis.
  • A study analyzed data from over 46,000 individuals to see if including NAFLD in the MetS criteria (referred to as MetS2) improved the accuracy of identifying those with metabolic issues and predicting health risks.
  • The findings showed that MetS2 identified an additional 8% of individuals with metabolic risk and was significantly associated with higher all-cause and cardiovascular disease mortality, highlighting the importance of early intervention.
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Background And Aims: Single nucleotide polymorphism rs6903956 has been identified as one of the genetic risk factors for coronary artery disease (CAD). However, rs6903956 lies in a non-coding locus on chromosome 6p24.1.

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Objective: Multiple trials on sodium-glucose cotransporter (SGLT) inhibitors have been performed recently demonstrating blood pressure (BP) reduction benefits in both diabetic and nondiabetic patients. Hence, we conducted a systematic review and meta-analysis to determine the effect of different SGLT inhibitors on BP in both patients with and without diabetes mellitus.

Methods: Four electronic databases (PubMed, Embase, Cochrane, and SCOPUS) were searched on 4 November 2021 for articles published from 1 January 2000 up to 21 November 2021, for studies evaluating the BP effects of SGLT inhibitors.

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Activated factor XI (FXIa) is an important antithrombotic drug target. Clinical and pre-clinical data have demonstrated that its inhibition attenuates thrombosis with minimal risk of excessive bleeding. We isolated Fasxiator from the venom of banded krait Bungarus fasciatus and subsequently engineered FasxiatorN17R,L19E, with improved affinity (Ki = 0.

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In patients with heart failure, the beneficial effects of drug and device therapies counteract to some extent ongoing cardiac damage. According to the net balance between these two factors, cardiac geometry and function may improve (reverse remodelling, RR) and even completely normalize (remission), or vice versa progressively deteriorate (adverse remodelling, AR). RR or remission predict a better prognosis, while AR has been associated with worsening clinical status and outcomes.

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We recently discovered that Mfsd2b, which is the S1P exporter found in blood cells. Here, we report that Mfsd2b is critical for the release of all S1P species in both resting and activated platelets. We show that resting platelets store S1P in the cytoplasm.

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We evaluated the cost-effectiveness of a genotype-guided strategy among patients with acute coronary syndromes using a decision-tree model based on the Singapore healthcare payer's perspective over a 1-year time horizon. Three dual antiplatelet strategies were considered: universal clopidogrel, genotype-guided, and universal ticagrelor. The prevalence of loss-of-function alleles was assumed to be 61.

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Circadian patterns in ST-segment elevation myocardial infarction (STEMI) patients have been previously reported, but little is known about the impact of time dependence of symptom onset on long-term prognosis. Our study population consisted of 11,731 STEMI patients treated by primary percutaneous coronary intervention (PPCI), enrolled in the Singapore Myocardial Infarction Registry (SMIR). Analysis of STEMI incidence trends over the 24-hour period showed the highest rate of symptom onset in the morning, with the peak incidence at 09:00 am.

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Background: Following an acute coronary syndrome, combined CT and PET with F-NaF can identify coronary atherosclerotic plaques that have ruptured or eroded. However, the processes behind F-NaF uptake in vulnerable plaques remain unclear.

Methods And Results: Ten patients with STEMI were scanned after F-NaF injection, for 75 minutes in a Siemens PET/MR scanner using delayed enhancement (LGE).

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Background: We examined the influence of sex, ethnicity, and time on competing cardiovascular and noncardiovascular causes of death following acute myocardial infarction in a multiethnic Asian cohort.

Methods And Results: For 12 years, we followed a prospective nationwide cohort of 15 151 patients (aged 22-101 years, median age 63 years; 72.3% male; 66.

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Introduction: This study aimed to examine the long-term clinical outcomes of coronary fractional flow reserve (FFR)-guided percutaneous coronary intervention (PCI) in a real-world population in an Asian tertiary centre.

Materials And Methods: All patients who underwent FFR measurement for intermediate coronary lesions in our centre from June 2002 to December 2009 were enrolled. A threshold of FFR ≤0.

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Background: The role of sex, and its joint effect with age and diabetes mellitus, on mortality subsequent to surviving an acute myocardial infarction (AMI) beyond 30 days are unclear. The high prevalence of diabetes mellitus in an ethnically diverse Asian population motivates this study.

Methods: The study population comprised of a nationwide cohort of Asian patients with AMI, hospitalized between 2000 to 2005, who survived the first 30 days post-admission and were followed prospectively until death or 12 years.

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Unlike vitamin K antagonists (VKAs), the new oral anticoagulants (NOACs)-direct thrombin inhibitor, dabigatran, and direct activated factor X inhibitors, rivaroxaban, and apixaban-do not require routine INR monitoring. Compared to VKAs, they possess relatively rapid onset of action and short halflives, but vary in relative degrees of renal excretion as well as interaction with p-glycoprotein membrane transporters and liver cytochrome P450 metabolic enzymes. Recent completed phase III trials comparing NOACs with VKAs for stroke prevention in atrial fibrillation (AF)-the RE-LY, ROCKET AF, and ARISTOTLE trials-demonstrated at least noninferior efficacy, largely driven by significant reductions in haemorrhagic stroke.

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The radial approach during percutaneous coronary intervention (PCI) has been reported to reduce the incidence of bleeding complications. However, the radial approach still accounts for <10% of procedures worldwide and only 1% in the United States. Our objective was to compare the effect of radial versus femoral vascular access on the time to reperfusion, incidence of bleeding complications, and overall clinical outcomes in the setting of primary PCI.

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