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 GRACE2 registries are prospective, multicenter, observational studies of patients with ACS (June 1999 to December 2007). For each patient, we calculated the GRACE risk score and evaluated its discrimination and calibration by the c statistic and the Hosmer-Lemeshow goodness-of-fit test, respectively. To assess the impact of temporal changes in management on the GRACE risk score performance, we evaluated its discrimination and calibration after stratifying the study population into prespecified subgroups according to enrollment period, type of ACS, and whether the patient underwent coronary angiography or revascularization during index hospitalization. Results A total of 12,242 Canadian patients with ACS were included; the median GRACE risk score was 127 (25th and 75th percentiles were 103 and 157, respectively). Overall, the GRACE risk score demonstrated excellent discrimination ( c statistic 0.84, 95% CI 0.82-0.86, P < .001) for in-hospital mortality. Similar results were seen in all the subgroups (all c statistics ≥0.8). However, calibration was suboptimal overall (Hosmer-Lemeshow P = .06) and in various subgroups. Conclusions GRACE risk score is a valid and powerful predictor of adverse outcomes across the wide range of Canadian patients with ACS. Its excellent discrimination is maintained despite advances in management over time and is evident in all patient subgroups. However, the predicted probability of in-hospital mortality may require recalibration in the specific health care setting and with advancements in treatment.
Abstract Randomized clinical trials are a major advance in clinical research methodology. However, there are myriad important questions about the effectiveness of treatments used in daily practice ...that are not informed by the results of randomized trials. This is in part because of important limitations inherent in the methodology of randomized efficacy trials which are performed with tight control of inclusion, exclusion, treatment, and follow-up. This approach enhances evaluation of clinical efficacy (performance in controlled situations) but increases complexity and is not well suited to test clinical effectiveness (performance under conditions of actual use). The cluster crossover trial is a new concept for efficient comparative effectiveness testing. Deep tissue infection occurs in 2% of patients after arrhythmia device implantation, usually requires system extraction, and increases mortality. There is variation in antibiotic prophylaxis used to reduce implanted device infections. To efficiently evaluate the comparative effectiveness of antibiotic strategies now in use, we designed a cluster crossover clinical trial, which randomized implanting centres to 1 of 2 prophylactic antibiotic strategies, which became the standard care at the centre for 6 months, followed by crossover to the other strategy, rerandomization, and second crossover. This method greatly reduces trial complexity because it aligns study procedures with usual clinical care and increases generalizability. Pilot studies have tested the feasibility and an 10,800-patient trial, funded by the Canadian Institutes of Health Research, is now under way. The cluster crossover randomized trial design is well suited to efficiently test comparative effectiveness of existing treatments where there is variability of practice, clinical equipoise, and minimal risk.
Objectives To evaluate vascular protection treatment patterns and attainment of the 2003 Canadian Diabetes Association's recommended targets in ambulatory patients with type 2 diabetes. Methods ...Between 2005 and 2006, 3002 outpatients with type 2 diabetes were enrolled by 229 primary health care settings across Canada. Baseline characteristics, therapeutic regimens and treatment success – defined as the achievement of a blood pressure (BP) of 130/80 mmHg or lower, glycosylated hemoglobin (A1C) of 7% or lower, low-density lipoprotein cholesterol (LDL-C) lower than 2.5 mmol/L and total cholesterol/ high-density lipoprotein cholesterol ratio lower than 4.0 – are reported. Results Overall, 46% of individuals had a BP that was above the Canadian Diabetes Association's recommended target. Of these, 11% were untreated, 28% were receiving monotherapy, 38% were not receiving an angiotensin-converting enzyme inhibitor and 16% were not receiving either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Optimal A1C levels were achieved in 53% of patients. Of those who did not attain A1C targets, 3% were not on glucose-lowering pharmacotherapy and 27% were receiving monotherapy. A total of 74% of patients were treated with statins. Overall, 64% and 62%, respectively, met the target LDL-C and the target total cholesterol/high-density lipoprotein cholesterol ratio. Statins were not prescribed to 43% of patients with LDL-C above target. Antiplatelet therapy was implemented in 81% of patients. In total, 21% achieved the combined targets for BP, A1C and LDL-C. Interpretation A substantial proportion of patients did not achieve guideline-recommended targets and were not receiving evidence-based therapy for vascular protection two years after publication of the Canadian guidelines. More research is warranted, and novel and effective strategies must be tested and implemented to correct this ongoing treatment gap.
Physical activity has a protective effect against cardiovascular disease (CVD) in high-income countries, where physical activity is mainly recreational, but it is not known if this is also observed ...in lower-income countries, where physical activity is mainly non-recreational. We examined whether different amounts and types of physical activity are associated with lower mortality and CVD in countries at different economic levels.
In this prospective cohort study, we recruited participants from 17 countries (Canada, Sweden, United Arab Emirates, Argentina, Brazil, Chile, Poland, Turkey, Malaysia, South Africa, China, Colombia, Iran, Bangladesh, India, Pakistan, and Zimbabwe). Within each country, urban and rural areas in and around selected cities and towns were identified to reflect the geographical diversity. Within these communities, we invited individuals aged between 35 and 70 years who intended to live at their current address for at least another 4 years. Total physical activity was assessed using the International Physical Activity Questionnaire (IPQA). Participants with pre-existing CVD were excluded from the analyses. Mortality and CVD were recorded during a mean of 6·9 years of follow-up. Primary clinical outcomes during follow-up were mortality plus major CVD (CVD mortality, incident myocardial infarction, stroke, or heart failure), either as a composite or separately. The effects of physical activity on mortality and CVD were adjusted for sociodemographic factors and other risk factors taking into account household, community, and country clustering.
Between Jan 1, 2003, and Dec 31, 2010, 168 916 participants were enrolled, of whom 141 945 completed the IPAQ. Analyses were limited to the 130 843 participants without pre-existing CVD. Compared with low physical activity (<600 metabolic equivalents MET × minutes per week or <150 minutes per week of moderate intensity physical activity), moderate (600–3000 MET × minutes or 150–750 minutes per week) and high physical activity (>3000 MET × minutes or >750 minutes per week) were associated with graded reduction in mortality (hazard ratio 0·80, 95% CI 0·74–0·87 and 0·65, 0·60–0·71; p<0·0001 for trend), and major CVD (0·86, 0·78–0·93; p<0·001 for trend). Higher physical activity was associated with lower risk of CVD and mortality in high-income, middle-income, and low-income countries. The adjusted population attributable fraction for not meeting the physical activity guidelines was 8·0% for mortality and 4·6% for major CVD, and for not meeting high physical activity was 13·0% for mortality and 9·5% for major CVD. Both recreational and non-recreational physical activity were associated with benefits.
Higher recreational and non-recreational physical activity was associated with a lower risk of mortality and CVD events in individuals from low-income, middle-income, and high-income countries. Increasing physical activity is a simple, widely applicable, low cost global strategy that could reduce deaths and CVD in middle age.
Population Health Research Institute, the Canadian Institutes of Health Research, Heart and Stroke Foundation of Ontario, Ontario SPOR Support Unit, Ontario Ministry of Health and Long-Term Care, AstraZeneca, Sanofi-Aventis, Boehringer Ingelheim, Servier, GSK, Novartis, King Pharma, and national and local organisations in participating countries that are listed at the end of the Article.
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 (4.0%) patients had QRS ≥120 milliseconds without BBB, 262 (5.2%) had left BBB (LBBB), and 250 (5.0%) had right BBB. Compared to patients with QRS <120 milliseconds, patients with QRS ≥120 milliseconds without BBB had higher in-hospital (3.5% vs 1.9%, odds ratio OR 1.87, 95% CI 0.85-4.09, P = .12) and 1-year mortality (14.9% vs 7.7%, OR 2.10, 95% CI 1.38-3.18, P = .001). In-hospital and 1-year mortality was significantly higher in patients with BBB (eg, LBBB compared with QRS <120 milliseconds) (5.0% vs 1.9%, OR 2.71, 95% CI 1.49-4.94, P = .001, and 23.8% vs 7.7%, OR 3.74, 95% CI 2.72-5.13, P < .001). Analyzed as a continuous variable and after adjustment for validated prognosticators, QRS duration was an independent predictor of 1-year death (OR 1.11, 95% CI 1.06-1.16, P < .001) and death/myocardial infarction (OR 1.06, 95% CI 1.02-1.11, P = .003). However, when using clinically applicable QRS duration evaluation, only LBBB was an independent predictor of 1-year mortality (OR 1.93, 95% CI 1.28-2.90, P = .002). Conclusions In patients presenting with a broad spectrum of suspected ACS, QRS prolongation—particularly in the setting of LBBB—is an independent predictor of in-hospital and 1-year mortality.
Aims An early invasive strategy after fibrinolysis for ST-elevation myocardial infarction (STEMI) improves outcomes, but the relative efficacy and safety of enoxaparin compared with unfractionated ...heparin (UFH) as part of this approach are unknown. Methods and Results In the TRANSFER-AMI trial, patients with high-risk STEMI received fibrinolysis and were then randomized to either standard treatment or to immediate transfer for coronary angiography. In this substudy, the outcome of patients aged <75 years treated with enoxaparin is compared with that of patients who received UFH. Logistic regression and propensity score models were used to evaluate the efficacy and safety of these anticoagulants. Enoxaparin was administered to 498 patients, and UFH, to 448 patients, at the time of fibrinolysis. Approximately 50% in each group were randomized to the early invasive strategy. The primary composite end point of death, reinfarction, recurrent ischemia, new or worsening heart failure, or cardiogenic shock at 30 days occurred in 11.9% and 11.6% of the patients who received enoxaparin and UFH, respectively (adjusted odds ratio 0.95 95% CI 0.60-1.51, P = .84). Enoxaparin use was associated with more access site bleeding (5.0% vs 2.9%, P = .04) and mild bleeding (12.1% vs 7.8%, P = .03). Conclusions Among high-risk patients with STEMI undergoing early or late transfer for cardiac catheterization after fibrinolysis, enoxaparin was associated with similar efficacy compared with UFH, but there was more minor bleeding with enoxaparin (ClinicalTrials.gov no. NCT00164190).
Until recently, guidelines for migraine prevention recommended avoiding known migraine headache triggers. Adhering to healthy lifestyle behaviors is also recommended. In a recent cohort study many ...triggers were found to decrease the probability of migraine attacks in some individuals. The extent to which people with migraine adhere to healthy lifestyle recommendations is unknown. We set out to determine if known migraine trigger factors and daily adherence to healthy lifestyle recommendations are associated with decreased probability of migraine attacks in some individuals.
This was an observational longitudinal cohort study of individuals with episodic migraine who registered to track their headache symptoms and daily exposure to trigger factors prospectively using a migraine-headache electronic diary during 90 days. We assessed whether triggers increased or decreased migraine attack risk in each individual. In addition, we calculated the proportion of days in which the individual adhered to lifestyle recommendations.
We analyzed a total of 1125 individuals contributing 14,080 migraine attacks. Out of 47 triggers, 24 were more often associated with decreased rather than with increased migraine attack risk. Most pronouncedly this was true for caffeine, alcohol, and chocolate; happiness; relaxedness; sleep factors (longer duration, higher quality, and waking up refreshed); and physical activity. People who were more compliant with healthy behaviors, especially keeping good hydration and regular meals, were significantly older and had been diagnosed with migraine disease for a longer period, compared to those who were less compliant. Overall, exercising ≥3 times a week was the least followed recommendation.
Many triggers behaved as protectors in a non-negligible proportion of individuals with episodic migraine, challenging the recommendation of avoiding known triggers. Low adherence to healthy lifestyle recommendations demonstrates an opportunity to increase awareness among people with migraine.
Objective
To assess whether alcohol intake is associated with the onset of migraine attacks up to 2 days after consumption in individuals with episodic migraine (EM).
Background
Although alcohol has ...long been suspected to be a common migraine trigger, studies have been inconclusive in proving this association.
Methods
This was an observational prospective cohort study among individuals with migraine who registered to use a digital health platform for headache. Eligible individuals were aged ≥18 years with EM who consumed alcohol and had tracked their headache symptoms and alcohol intake for ≥90 days. People who did not drink any alcohol were excluded. The association of alcohol intake (“Yes/No”) and of the number of alcoholic beverages in the 2 days preceding a migraine attack was assessed accounting for the presence of migraine on day‐2 and its interaction with alcohol intake on day‐2, and further adjusted for sex, age, and average weekly alcohol intake.
Results
Data on 487 individuals reporting 5913 migraine attacks and a total of 40,165 diary days were included in the analysis. Presence of migraine on day‐2 and its interaction with alcohol intake on day‐2 were not significant and removed from the model. At the population level, alcohol intake on day‐2 was associated with a lower probability of migraine attack (OR 95% CI = 0.75 0.68, 0.82; event rate 1006/4679, 21.5%), while the effect of alcohol intake on day‐1 was not significant (OR 95% CI = 1.01 0.91, 1.11; event rate 1163/4679, 24.9%) after adjusting for sex, age, and average weekly alcohol intake. Similar results were obtained with the number of beverages as exposure.
Conclusions
In this English‐speaking cohort of individuals with EM who identified themselves as mostly low‐dose alcohol consumers, there was no significant effect on the probability of a migraine attack in the 24 h following consumption, and a slightly lower likelihood of a migraine attack from 24 to 48 h following use.
Two‐way contingency tables arise in many fields, such as in medical studies, where the relation between two discrete random variables or responses is to be assessed. We propose to analyze and ...visualize a sample of 2 × 2 tables in the context of single‐subject repeated measurements design by means of compositional data (CoDa) methods. First, we propose to visualize the tables in a quaternary diagram. Second, we show how to represent these tables by means of logratios indicating the relationship between the two variables as well as their strength and direction of dependency. Finally, we describe a technique to model those tables with a simplicial regression model. Data from a real‐world study of self‐prediction of migraine attack onset is used to illustrate this methodology. For each individual, the 2 × 2 table of their migraine expectation vs next day migraine occurrence is computed, generating a sample of tables. Then we visualize and interpret the prediction ability of individuals both in the simplex and in terms of logratios of components. Finally, we model the self‐prediction ability with respect to demographic variables, days tracked and disease characteristics. Our application demonstrates that CoDa can be a useful tool for visualizing, modeling, and interpreting the components of 2 × 2 tables.
PDF
