Publications by authors named "Andrew Yan"
Background: Left ventricular hypertrophy (LVH) is frequently associated with ST depression (STD) on the electrocardiogram (ECG), a so-called strain pattern. Although STD is a well-established adverse prognosticator in non-ST-elevation acute coronary syndrome (NSTE-ACS), the relative prognostic importance of LVH and associated STD has not been elucidated.
Methods: A total of 7,761 patients with NSTE-ACS in the Global Registry of Acute Coronary Events (GRACE) and ACS-I registries had admission ECGs analyzed at a core laboratory.
Up to one third of the population will die as a direct result of cancer. Accurate and timely diagnosis of disease often requires multiple different approaches including the use of modern imaging techniques. Prompt recognition of adverse consequences of some anti-cancer therapies also requires a knowledge of the optimum imaging strategy for the problem at hand.
View Article and Find Full Text PDFAims Previous studies have reported differences in the use of cardiovascular medications for acute coronary syndromes (ACSs) according to the sex of the patient. We analysed which clinical factors are associated with underutilization of evidence-based therapies in women. Methods and results From the Canadian Registry of ACS I and II, 6558 patients (4471 men and 2087 women) with a final diagnosis of ACS were selected for the current analysis.
View Article and Find Full Text PDFBackground: The COMMIT/CCS-2 trial, published in 2005, demonstrated no net benefit of early β-blocker (BB) therapy in acute coronary syndromes (ACS). We sought to assess the short-term impact of this landmark trial by comparing the use of early BB therapy in patients with a broad spectrum of ACS before and after 2005.
Methods: Using data from the Global Registry of Acute Coronary Events and Canadian Registry of Acute Coronary Events, we compared the rates of BB use within the first 24 hours of presentation in the periods 1999 to 2005 and 2006 to 2008, after stratifying patients by the type of ACS (ST-segment elevation myocardial infarction [STEMI] and non-ST-segment elevation ACS [NSTEACS]) and clinical presentation.
Aims: We sought to determine the effectiveness of early routine percutaneous coronary intervention (PCI) post-fibrinolysis for ST-elevation myocardial infarction (STEMI) in relation to baseline risk status.
Methods And Results: In this post hoc subgroup analysis of Trial of Routine Angioplasty and Stenting after Fibrinolysis to Enhance Reperfusion in Acute Myocardial Infarction (TRANSFER-AMI), we stratified 1059 STEMI patients receiving tenecteplase into low-intermediate [Global Registry of Acute Coronary Events (GRACE) risk score<155; n=889] vs. high-risk (GRACE risk score ≥155; n=170) groups, based on the GRACE risk score for in-hospital mortality.
Background: Smoking induces CYP1A2, thereby enhancing clopidogrel conversion to its active metabolite. We sought to determine the association between clopidogrel use and clinical outcomes in smokers versus nonsmokers with a broad spectrum of acute coronary syndrome (ACS).
Methods: We examined the association between early clopidogrel use in-hospital and 6-month outcomes among 44,426 patients with ACS in relation to smoking status in the Global Registry of Acute Coronary Events.
Background: The objective of this study was to determine if the extent of quantitative troponin elevation predicted mortality as well as in-hospital complications of cardiac arrest, new heart failure and cardiogenic shock.
Design: 16,318 patients with non-ST-segment elevation acute coronary syndromes (NSTE ACS) from the Global Registry of Acute Coronary Events (GRACE) were included. The maximum 24 h troponin value as a multiple of the local laboratory upper limit of normal was used.
Anemia has been associated with adverse outcomes in patients with acute coronary syndromes (ACS). However, the underlying pathophysiologic mechanisms have not been well elucidated. We sought to determine the independent relation between the hemoglobin level and recurrent ischemia in patients with non-ST-segment elevation ACS using continuous electrocardiographic monitoring.
View Article and Find Full Text PDFPrevious studies have questioned the external validity of randomized controlled trial results of acute coronary syndrome (ACS) because of potential selection bias toward healthier patients. We sought to evaluate differences in clinical characteristics and management of patients admitted with non-ST-elevation ACS according to participation in clinical trials over the previous decade. The Canadian ACS I (1999 to 2001), ACS II (2002-2003), GRACE (2004-2007), and CANRACE (2008) were prospective, multicenter registries of patients admitted to hospitals with ACS.
View Article and Find Full Text PDFObesity is associated with hypertension, dyslipidemia, and diabetes, but it is also an independent cardiovascular risk factor. We sought to evaluate the differences in treatment patterns and attainment of guideline-recommended targets among high-risk vascular outpatients in relation to their body mass index (BMI). The prospective Vascular Protection and Guideline Orientated Approach to Lipid Lowering Registries recruited 7,357 high-risk vascular outpatients in Canada from 2001 to 2004.
View Article and Find Full Text PDFBackground: Increasing evidence suggests that elevated plasma fibrinogen is associated with incident heart failure. However, the underlying pathophysiological mechanisms have not been well elucidated.
Methods: We examined the relationship between plasma fibrinogen level and peak systolic midwall circumferential strain (Ecc) at the base, mid cavity, and apex of the left ventricle measured by magnetic resonance imaging myocardial tagging in 1096 participants without clinical cardiovascular disease enrolled in the Multi-Ethnic Study of Atherosclerosis (MESA).
Background: Although randomized controlled trials support the use of intensive medical and invasive therapies for non-ST segment elevation acute coronary syndromes (NSTE-ACS), major bleeding is a serious treatment complication. We sought to determine the temporal trend of in-hospital major bleeding among patients with NSTE-ACS, in relation to the evolving management pattern.
Methods: We identified 14 111 NSTE-ACS patients enrolled in 4 successive, prospective, multicenter registries (ACS I, 1999-2001; ACS II, 2002-2003; GRACE, 2004-2007; and CANRACE, 2008) in Canada between 1999 and 2008.
Objective: To identify factors in patients with type 2 diabetes and A1C >7.0% associated with attainment of A1C ≤ 7.0%.
View Article and Find Full Text PDFBackground: Acute coronary syndrome (ACS) patients in the highest risk categories are least likely to receive evidence-based treatments (EBTs). We sought to determine why physicians do not prescribe EBTs for patients with non-ST-segment-elevation ACSs and the factors determining use of these treatments after 1 year.
Methods And Results: One thousand nine hundred fifty-six non-ST-segment-elevation ACS patients were enrolled in the prospective, multicenter Canadian ACS registry II between October 2002 and December 2003.
Cerebrovascular (CVD) disease is commonly associated with coronary artery disease and adversely affects outcome. The goal of the present study was to examine the temporal management patterns and outcomes in relation to previous CVD in a contemporary "real-world" spectrum of patients with acute coronary syndrome (ACS). From 1999 to 2008, 14,070 patients with non-ST-segment elevation ACS were recruited into the Canadian Acute Coronary Syndrome I (ACS I), ACS II, Global Registry of Acute Coronary Events (GRACE/GRACE(2)), and Canadian Registry of Acute Coronary Events (CANRACE) prospective multicenter registries.
View Article and Find Full Text PDFBackground: In-hospital assessment of left ventricular ejection fraction (LVEF) in non-ST-segment elevation acute coronary syndrome (NSTE-ACS) is emphasized in current practice guidelines. There are limited data regarding the evaluation of LVEF and clinical characteristics and in-hospital management in the "real world."
Methods: Registries including the Canadian Acute Coronary Syndrome (ACS) I and II, Global Registry of Acute Coronary Events (main GRACE/expanded GRACE(2)), and Canadian Registry of Acute Coronary Events (CANRACE) enrolled 13,703 NSTE-ACS patients across Canada between 1999 and 2008.
Background: QRS prolongation with or without bundle branch block (BBB) has been associated with adverse outcome in myocardial infarction; we examined the relationship between QRS duration and outcome in a broad spectrum of patients with acute coronary syndrome (ACS).
Method And Results: Core laboratory evaluation of the presenting electrocardiogram in Canadian ACS Registry patients (n = 5,003) showed 4,289 (85.7%) had QRS <120 milliseconds, 202 (4.
Background: Left ventricular systolic dysfunction (LVSD) is frequently observed in patients with advanced chronic kidney disease (CKD) and its presence is associated with a poor prognosis. Renin-angiotensin system (RAS) inhibition and beta-adrenergic blockade are the cornerstones of medical management for LVSD. Current guidelines advocate that CKD patients with advanced LVSD should receive these therapies.
View Article and Find Full Text PDFBackground: Contemporary guidelines support an early invasive strategy for non-ST elevation acute coronary syndrome (NSTE-ACS) patients who had prior coronary revascularization. However, little is known about the management pattern of these patients in "real world."
Methods: We analyzed 3 consecutive Canadian registries (ACS I, ACS II, and Global Registry of Acute Coronary Events [GRACE]/expanded-GRACE) that recruited 12,483 NSTE-ACS patients from June 1999 to December 2007.
Aims: We sought to examine the relationship between circulating interleukin-6 (IL-6) level and regional left-ventricular (LV) function among apparently healthy individuals free of cardiovascular disease.
Methods And Results: Using magnetic resonance myocardial tagging, we determined peak systolic circumferential strain (Ecc) as a measure of regional systolic function in 894 asymptomatic participants in the Multi-Ethnic Study of Atherosclerosis. Ecc was analysed by harmonic phase imaging separately in the LV anterior wall, septum, lateral wall, and inferior wall.
Aims: Although ST-segment depression (STD) on the admission electrocardiogram (ECG) confers adverse prognosis in patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS), the implications of STD on follow-up ECG remain uncertain. We determined the prognostic significance of STD on follow-up ECG performed within 12-24 h of admission and whether its quantitative evaluation can further refine risk stratification.
Methods And Results: The admission and follow-up ECGs of 3877 patients in the SYNERGY trial were analysed for the presence (>or=1 mm) and extent (maximum magnitude on any single lead) of STD.
Background: There are limited contemporary data on the early use of clopidogrel or glycoprotein (Gp) IIb/IIIa inhibitors, alone versus combination therapies, in non-ST-elevation acute coronary syndrome (NSTE-ACS).
Methods: This study included 5,806 Canadian NSTE-ACS patients with elevated cardiac biomarker and/or ST deviation on presentation in the prospective GRACE between 2003-2007. We stratified the study population according to the management strategy (non-invasive vs invasive) and into low-(GRACE risk score
Background: The Global Registry of Acute Coronary Event (GRACE) risk score was developed in a large multinational registry to predict in-hospital mortality across the broad spectrum of acute coronary syndromes (ACS). Because of the substantial regional variation and temporal changes in patient characteristics and management patterns, we sought to validate this risk score in a contemporary Canadian population with ACS.
Methods: The main GRACE and GRACE(2) registries are prospective, multicenter, observational studies of patients with ACS (June 1999 to December 2007).
Background: The Global Registry of Acute Coronary Events (GRACE)-a prospective, multinational study of patients hospitalized with acute coronary syndromes (ACSs)-was designed to improve the quality of care for patients with an ACS. Expanded GRACE aims to test the feasibility of a simplified data collection tool and provision of quarterly feedback to index individual hospital management practices to an international reference cohort.
Methods: We describe the objectives; study design; study and data management; and the characteristics, management, and hospital outcomes of patients > or =18 years old enrolled with a presumptive diagnosis of ACS.