Tobacco use and risk of acute stroke in 32 countries in the INTERSTROKE study: a case-control study

Background

Smoking is a major risk factor for the global burden of stroke. We have previously reported a global population attributable risk (PAR) of stroke of 12.4% associated with current smoking. In this study we aimed to explore the association of current tobacco use with different types of tobacco exposure and environmental tobacco smoke (ETS) exposure on the risk of stroke and stroke subtypes, and by regions and country income levels.

Methods

The INTERSTROKE study is a case-control study of acute first stroke and was undertaken with 13,462 stroke cases and 13,488 controls recruited between January 11, 2007 and August 8, 2015 in 32 countries worldwide. Association of risk of tobacco use and ETS exposure were analysed with overall stroke, ischemic and intracerebral hemorrhage (ICH), and with TOAST etiological stroke subtypes (large vessel, small vessel, cardioembolism, and undetermined).

Findings

Current smoking was associated with an increased risk of all stroke (odds ratio [OR] 1.64, 95% CI 1.46-1.84), and had a stronger association with ischemic stroke (OR 1.85, 95% CI 1.61-2.11) than ICH (OR 1.19 95% CI 1.00-1.41). The OR and PAR of stroke among current smokers varied significantly between regions and income levels with high income countries (HIC) having the highest odds (OR 3.02 95% CI 2.24-4.10) and PAR (18.6%, 15.1-22.8%). Among etiological subtypes of ischemic stroke, the strongest association of current smoking was seen for large vessel stroke (OR 2.16, 95% CI 1.63-2.87) and undetermined cause (OR 1.97, 95% CI 1.55-2.50). Both filtered (OR 1.73, 95% CI 1.50-1.99) and non-filtered (OR 2.59, 95% CI 1.79-3.77) cigarettes were associated with stroke risk. ETS exposure increased the risk of stroke in a dose-dependent manner, exposure for more than 10 h per week increased risk for all stroke (OR 1.95, 95% CI 1.69-2.27), ischemic stroke (OR 1.89, 95% CI 1.59-2.24) and ICH (OR 2.00, 95% CI 1.60-2.50).

Interpretation

There are significant variations in the magnitude of risk and PAR of stroke according to the types of tobacco used, active and ETS exposure, and countries with different income levels. Specific strategies to discourage tobacco use by any form and to build a smoke free environment should be implemented to ease the global burden of stroke.

Funding

The Canadian Institutes of Health Research, Heart and Stroke Foundation of Canada, Canadian Stroke Network, Swedish Research Council, Swedish Heart and Lung Foundation, The Health & Medical Care Committee of the Regional Executive Board, Region Västra Götaland, and through unrestricted grants from several pharmaceutical companies with major contributions from Astra Zeneca, Boehringer Ingelheim (Canada), Pfizer (Canada), MERCK, Sharp and Dohme, Swedish Heart and Lung Foundation, UK Chest, and UK Heart and Stroke.

Rethinking Data Collection Methods During the Pandemic: Development and Implementation of CATI for the All of Us Research Program

The All of Us Research Program is a longitudinal cohort study aiming to build a diverse database to advance precision medicine. The COVID-19 pandemic hindered the ability of participants to receive in-person assistance at enrollment sites to complete digital surveys. Therefore, the program implemented Computer-Assisted Telephone Interviewing (CATI) to facilitate survey completion remotely to combat the disrupted data collection procedures. In January 2021, All of Us implemented a 1-year CATI Pilot supporting 9399 participants and resulting in 16 337 submitted surveys. The pilot showed that CATI was successful in increasing survey completion and retention activities for the All of Us Research Program, given the additional remote support offered to participants. Given the success of the CATI Pilot, multimodal survey administration will continue.

The Clinical Validation of a Common Analytical Change Criteria for Cardiac Troponin for Ruling in an Acute Cardiovascular Outcome in Patients Presenting with Ischemic Chest Pain Symptoms

Serial cardiac troponin (cTn) testing on patients with symptoms suggestive of acute coronary syndrome (ACS) is primarily to identify those patients with evolving myocardial injury. With the improved analytical performance of the high-sensitivity cTn (hs-cTn) assays, different change criteria have been proposed that are mostly assay dependent. Here, we developed and compared a new Common Change Criteria (3C for the combined criteria of >3 ng/L, >30%, or >15% based on the initial cTn concentration of <10 ng/L, 10 to 100 ng/L, or >100 ng/L, respectively) method, versus the 2 h assay-dependent absolute change criteria endorsed by the European Society of Cardiology (ESC), versus the common relative >20% change criterion. These different analytical change criteria were evaluated in 855 emergency department (ED) patients with symptoms of ACS and who had two samples collected 3 h apart. The cTn concentrations were measured with four different assays (Abbott hs-cTnI, Roche hs-cTnT, Ortho cTnI-ES, and Ortho hs-cTnI). The outcomes evaluated were myocardial infarction (MI) and a composite outcome (MI, unstable angina, ventricular arrhythmia, heart failure, or cardiovascular death) within 7 days of ED presentation. The combined change criteria (3C) method yielded higher specificities (range: 93.9 to 97.2%) as compared to the >20% criterion (range: 42.3 to 88.1%) for all four assays for MI. The 3C method only yielded a higher specificity estimate for MI for the cTnI-ES assay (95.9%) versus the absolute change criteria (71.7%). Similar estimates were obtained for the composite outcome. There was also substantial agreement between hs-cTnT and the different cTnI assays for MI with the 3C method, with the percent agreement being ≥95%. The Common Change Criteria (3C) method combining both absolute and different percent changes may be used with cTnI, hs-cTnT, and different hs-cTnI assays to yield similar high-specificity (rule-in) estimates for adverse cardiovascular events for patients presenting to the ED with ACS symptoms.

Association of Lipids, Lipoproteins, and Apolipoproteins with Stroke Subtypes in an International Case Control Study (INTERSTROKE)

Background and Purpose The association of dyslipidemia with stroke has been inconsistent, which may be due to differing associations within etiological stroke subtypes. We sought to determine the association of lipoproteins and apolipoproteins within stroke subtypes.Methods Standardized incident case-control STROKE study in 32 countries. Cases were patients with acute hospitalized first stroke, and matched by age, sex and site to controls. Concentrations of total cholesterol, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), apolipoprotein A1 (apoA1), and apoB were measured. Non-HDL-C was calculated. We estimated multivariable odds ratio (OR) and population attributable risk percentage (PAR%). Outcome measures were all stroke, ischemic stroke (and subtypes), and intracerebral hemorrhage (ICH).Results Our analysis included 11,898 matched case-control pairs; 77.3% with ischemic stroke and 22.7% with ICH. Increasing apoB (OR, 1.10; 95% confidence interval [CI], 1.06 to 1.14 per standard deviation [SD]) and LDL-C (OR, 1.06; 95% CI, 1.02 to 1.10 per SD) were associated with an increase in risk of ischemic stroke, but a reduced risk of ICH. Increased apoB was significantly associated with large vessel stroke (PAR 13.4%; 95% CI, 5.6 to 28.4) and stroke of undetermined cause. Higher HDL-C (OR, 0.75; 95% CI, 0.72 to 0.78 per SD) and apoA1 (OR, 0.63; 95% CI, 0.61 to 0.66 per SD) were associated with ischemic stroke (and subtypes). While increasing HDL-C was associated with an increased risk of ICH (OR, 1.20; 95% CI, 1.14 to 1.27 per SD), apoA1 was associated with a reduced risk (OR, 0.80; 95% CI, 0.75 to 0.85 per SD). ApoB/A1 (OR, 1.38; 95% CI, 1.32 to 1.44 per SD) had a stronger magnitude of association than the ratio of LDL-C/HDL-C (OR, 1.26; 95% CI, 1.21 to 1.31 per SD) with ischemic stroke (<i>P</i><0.0001). Conclusions The pattern and magnitude of association of lipoproteins and apolipoproteins with stroke varies by etiological stroke subtype. While the directions of association for LDL, HDL, and apoB were opposing for ischemic stroke and ICH, apoA1 was associated with a reduction in both ischemic stroke and ICH. The ratio of apoB/A1 was the best lipid predictor of ischemic stroke risk.

Biomarkers of Prevalent and Incident Cognitive Dysfunction in People with Dysglycemia- Data from the ORIGIN Trial

Background: Diabetes and cardiovascular disease increase the risk of incident cognitive dysfunction. Identification of novel biochemical markers for cognitive dysfunction may identify people at the highest risk while yielding insights regarding the pathophysiology of cognitive dysfunction. Objective: To identify cardiovascular biomarkers in serum that are independent predictors of cognitive dysfunction in individuals with dysglycemia. Methods: This analysis was conducted in 8,365 participants in the Outcome Reduction with an Initial Glargine Intervention (ORIGIN) trial whose stored serum was analyzed for 238 cardio-metabolic biomarkers and completed a baseline Mini-Mental State Examination (MMSE). Fine and Gray sub distribution hazard models accounting for the competing risk of death accounting for clinical risk factors and the baseline MMSE were used to identify biomarkers that predicted incident cognitive dysfunction (MMSE <  24 or dementia) using forward selection with an inclusion p-value <  0.0002 to account for multiplicity. Results: During a median follow-up period of 6.2 years, 939 individuals developed cognitive dysfunction. After accounting for 17 clinical risk factors, glargine allocation, and the baseline MMSE, three biomarkers (α-2 Macroglobulin, HR 1.19; 95% CI 1.12, 1.27; Macrophage Inflammatory Protein 1α, HR 1.11; 95% CI 1.06, 1.16; and Growth Hormone, HR 0.91; 95% CI 0.87, 0.96) independently predicted incident cognitive dysfunction (p <  0.0002). Addition of these biomarkers to a model that included clinical risk factors, however, did not improve the ability to predict cognitive dysfunction. Conclusion: Addition of independent biomarkers to clinical risk factors for cognitive dysfunction in people with dysglycemia did not predict incident cognitive dysfunction better than clinical risk factors alone.

The psychological impact of paediatric burn injuries: a systematic review

OBJECTIVE

To review and synthesise qualitative literature regarding the psychological outcomes following paediatric burn injuries, and to determine if children and adolescents who experience a burn injury have elevated risk of psychopathology following the injury.

DESIGN

Systematic review of quantitative and qualitative studies.

DATA SOURCES

Informit health, Medline, Embase, and PsycINFO were searched from January 2010 to December 2020.

DATA EXTRACTION AND SYNTHESIS

Two reviewers screened articles, and one reviewer extracted data (with cross-checking from another reviewer) from the included studies and assessed quality using an established tool. Narrative synthesis was used to synthesise the findings from the quantitative studies, and thematic synthesis was used to synthesise the findings of included qualitative studies.

RESULTS

Searches yielded 1240 unique titles, with 130 retained for full-text screening. Forty-five studies from 17 countries were included. The psychological outcomes included in the studies were mental health diagnoses, medication for mental illness, depression, anxiety, stress, fear, post-traumatic stress, post-traumatic growth, emotional issues, self-harm, self-esteem, self-concept, stigmatisation, quality of life, level of disability, resilience, coping, and suicidality.

CONCLUSIONS

Our findings highlight paediatric burn patients as a particularly vulnerable population following a burn injury. Studies suggest elevated anxiety and traumatic stress symptoms, and higher rates of psychopathology in the long-term. Further research is recommended to determine the psychological outcomes in the other mental health domains highlighted in this review, as findings were mixed. Clinical care teams responsible for the aftercare of burn patients should involve psychological support for the children and families to improve outcomes.

NT-proBNP versus routine clinical risk factors as a predictor of cardiovascular events or death in people with dysglycemia - A brief report from the ORIGIN trial

In patients with diabetes and cardiovascular or renal comorbidities, circulating levels of the N-terminal fragment of prohormone B-type natriuretic peptide (NT-proBNP) have similar discriminatory ability as multivariate models for prediction of cardiovascular events or death. We validated this finding in patients with dysglycemia not selected for co-existing cardiorenal diseases.

Using the clinical chemistry score in the emergency department to detect adverse cardiac events: a diagnostic accuracy study

BACKGROUND

The ability to rule out or in a major adverse cardiac event (MACE) in patients with suspected acute coronary syndrome at emergency department (ED) presentation would be beneficial to patient care and the health care system. The clinical chemistry score (CCS) was evaluated in this context.

METHODS

This diagnostic accuracy study evaluated 2 different ED cohorts with suspected acute coronary syndrome. For patients in cohort 1, who presented to the ED of 3 hospitals in Hamilton, Ontario, between May and August 2013, retrospective measurements were taken using the Ortho Clinical Diagnostics high-sensitivity cardiac troponin I (hs-cTnI) assay; for patients in cohort 2, who presented to the ED of the same 3 hospitals in Hamilton between November 2012 and February 2013, an ED cardiac presentation blood test panel was performed with the Abbott Diagnostics hs-cTnI assay. The sensitivity and specificity of the CCS (cut-offs of ≥ 1 and 5) and hs-cTnI alone (published cut-offs) were compared for MACE (composite of death, myocardial infarction, unstable angina, revascularization) at 30 days for both cohorts and at 90 days for cohort 2.

RESULTS

The incidence of MACE at 30 days was higher in cohort 1 (n = 1058) (19.4%, 95% confidence interval [CI] 16.8%-22.2%) than in cohort 2 (n = 5974) (14.6%, 95% CI 13.6%-15.6%). In cohort 1, a CCS of 1 or above yielded a sensitivity of 99.5% (95% CI 97.3%-99.9%). The sensitivity with an Ortho hs-cTnI cut-off of 1 ng/L or above was 91.2% (95% CI 86.5%-95.7%). The specificity of a CCS of 5 (97.8%, 95% CI 96.5%-98.7%) was higher than when the overall 99th-percentile cut-off for the Ortho hs-cTnI assay (> 11 ng/L; 90.1%, 95% CI 87.9%-92.0%) was used. A similar pattern was observed in cohort 2 at 30 days and persisted at 90 days with the Abbott hs-cTnI assay.

INTERPRETATION

The CCS derived with 2 different hs-cTnI assays and ED populations yielded higher sensitivity and specificity estimates for MACE than hs-cTnI alone. An intervention study is needed to evaluate the impact of the CCS at both the patient and hospital levels.

TRIAL REGISTRATION

ClinicalTrials.gov, no. NCT01994577.

Comparison of two biomarker only algorithms for early risk stratification in patients with suspected acute coronary syndrome

BACKGROUND

We developed a biomarker algorithm encompassing the clinical chemistry score (CCS; which includes the combination of a random glucose concentration, an estimated glomerular filtration rate and high-sensitivity cardiac troponin; hs-cTn) with the Ortho Clinical Diagnostics hs-cTnI assay (CCS-serial) and compared it to the cutoffs derived from Ortho Clinical Diagnostics 0/1 h (h) algorithm for 7-day myocardial infarction (MI) or cardiovascular (CV)-death.

METHODS

The study cohort was an emergency department (ED) population (n = 906) with symptoms suggestive of acute coronary syndrome (ACS) who had two Ortho hs-cTnI results approximately 3 h apart. Diagnostic parameters (sensitivity/specificity/negative predictive value; NPV/positive predictive value; PPV) were derived for the CCS-serial and the 0/1 h algorithm for 7-day MI/CV-death. A safety analysis was performed for patients in the rule-out arms of the algorithms for 30-day MI/death.

RESULTS

The CCS-serial algorithm yielded 100% sensitivity/NPV (32% low-risk) and 95.7% specificity/65% PPV (11% high-risk). The 0/1 h algorithm-cutoffs yielded sensitivity/NPV/specificity/PPV of 97.8%/99.4%/91.3%/50%, which classified 38% of patients as low-risk and 16% of patients as high-risk. Four patients (1.2%) in the 0/1 h algorithm-cutoff rule-out arm had a 30-day MI/death outcome as compared to zero patients in the CCS-serial rule-out arm (p = 0.06).

CONCLUSION

Both the CCS-serial and 0/1 h algorithm cutoffs yield high NPVs with a similar proportion of patients identified as low-risk. These data may be useful for sites who are unable to collect samples at 0/1 h in the emergency department.

Clinical evaluation of Ortho Clinical Diagnostics high-sensitivity cardiac Troponin I assay in patients with symptoms suggestive of acute coronary syndrome

BACKGROUND

As more companies obtain regulatory approval for high-sensitivity cardiac troponin (hs-cTn) assays there is an urgent need for independent analytical and clinical evaluations. To this end, we have evaluated Ortho Clinical Diagnostics' hs-cTnI assay and compared it to their contemporary cTnI-ES assay in emergency department (ED) patients with suspected acute coronary syndrome (ACS).

METHODS

The study cohort consisted of ED patients (n = 906) with symptoms suggestive of ACS who had Ortho hs-cTnI and cTnI-ES results at presentation and 3 h (with calculated delta (0-3 h) defined as the absolute concentration difference between paired results). The primary composite outcome was 7-day myocardial infarction (MI) or cardiovascular death, with secondary analyses performed for 7-day MI and index-MI. Analytical imprecision testing (i.e., coefficient of variation; CV), receiver-operating characteristic (ROC) curve analyses with area under the curve (AUC), and diagnostic parameters (sensitivity/specificity/predictive values) were calculated.

RESULTS

The hs-cTnI assay had superior precision compared to the cTnI-ES assay below 5 ng/L in EDTA plasma (hs-cTnI CV ≤ 15% versus cTnI-ES CV ≥ 85%). The AUCs were higher for hs-cTnI as compared to cTnI-ES at 0 h (0.88 vs. 0.85), 3 h (0.94 vs. 0.92), and the delta (0-3 h) value (0.91 vs. 0.85) for the primary composite outcome (p < 0.05). At 3 h, the sensitivity/specificity for index-MI was ≥97%/≥82%, for 7-day MI was ≥89%/≥84%, and for the primary composite outcome was ≥90%/≥85% using the manufacturer's sex-specific 99th-percentile cutoffs.

CONCLUSION

The Ortho hs-cTnI assay has superior analytical and clinical performance over their contemporary cTnI-ES assay in evaluating ED patients with symptoms suggestive of ACS.

Preoperative N-Terminal Pro-B-Type Natriuretic Peptide and Cardiovascular Events After Noncardiac Surgery: A Cohort Study

BACKGROUND

Preliminary data suggest that preoperative N-terminal pro-B-type natriuretic peptide (NT-proBNP) may improve risk prediction in patients undergoing noncardiac surgery.

OBJECTIVE

To determine whether preoperative NT-proBNP has additional predictive value beyond a clinical risk score for the composite of vascular death and myocardial injury after noncardiac surgery (MINS) within 30 days after surgery.

DESIGN

Prospective cohort study.

SETTING

16 hospitals in 9 countries.

PATIENTS

10 402 patients aged 45 years or older having inpatient noncardiac surgery.

MEASUREMENTS

All patients had NT-proBNP levels measured before surgery and troponin T levels measured daily for up to 3 days after surgery.

RESULTS

In multivariable analyses, compared with preoperative NT-proBNP values less than 100 pg/mL (the reference group), those of 100 to less than 200 pg/mL, 200 to less than 1500 pg/mL, and 1500 pg/mL or greater were associated with adjusted hazard ratios of 2.27 (95% CI, 1.90 to 2.70), 3.63 (CI, 3.13 to 4.21), and 5.82 (CI, 4.81 to 7.05) and corresponding incidences of the primary outcome of 12.3% (226 of 1843), 20.8% (542 of 2608), and 37.5% (223 of 595), respectively. Adding NT-proBNP thresholds to clinical stratification (that is, the Revised Cardiac Risk Index [RCRI]) resulted in a net absolute reclassification improvement of 258 per 1000 patients. Preoperative NT-proBNP values were also statistically significantly associated with 30-day all-cause mortality (less than 100 pg/mL [incidence, 0.3%], 100 to less than 200 pg/mL [incidence, 0.7%], 200 to less than 1500 pg/mL [incidence, 1.4%], and 1500 pg/mL or greater [incidence, 4.0%]).

LIMITATION

External validation of the identified NT-proBNP thresholds in other cohorts would reinforce our findings.

CONCLUSION

Preoperative NT-proBNP is strongly associated with vascular death and MINS within 30 days after noncardiac surgery and improves cardiac risk prediction in addition to the RCRI.

PRIMARY FUNDING SOURCE

Canadian Institutes of Health Research.

Lipoprotein(a) Levels and the Risk of Myocardial Infarction Among 7 Ethnic Groups

BACKGROUND

Lipoprotein(a) [Lp(a)] levels predict the risk of myocardial infarction (MI) in populations of European ancestry; however, few data are available for other ethnic groups. Furthermore, differences in isoform size distribution and the associated Lp(a) concentrations have not fully been characterized between ethnic groups.

METHODS

We studied 6086 cases of first MI and 6857 controls from the INTERHEART study that were stratified by ethnicity and adjusted for age and sex. A total of 775 Africans, 4443 Chinese, 1352 Arabs, 1856 Europeans, 1469 Latin Americans, 1829 South Asians, and 1221 Southeast Asians were included in the study. Lp(a) concentration was measured in each participant using an assay that was insensitive to isoform size, with isoform size being assessed by Western blot in a subset of 4219 participants.

RESULTS

Variations in Lp(a) concentrations and isoform size distributions were observed between populations, with Africans having the highest Lp(a) concentration (median=27.2 mg/dL) and smallest isoform size (median=24 kringle IV repeats). Chinese samples had the lowest concentration (median=7.8 mg/dL) and largest isoform sizes (median=28). Overall, high Lp(a) concentrations (>50 mg/dL) were associated with an increased risk of MI (odds ratio, 1.48; 95% CI, 1.32-1.67; P<0.001). The association was independent of established MI risk factors, including diabetes mellitus, smoking, high blood pressure, and apolipoprotein B and A ratio. An inverse association was observed between isoform size and Lp(a) concentration, which was consistent across ethnic groups. Larger isoforms tended to be associated with a lower risk of MI, but this relationship was not present after adjustment for concentration. Consistent with variations in Lp(a) concentration across populations, the population-attributable risk of high Lp(a) for MI varied from 0% in Africans to 9.5% in South Asians.

CONCLUSIONS

Lp(a) concentration and isoform size varied markedly between ethnic groups. Higher Lp(a) concentrations were associated with an increased risk of MI and carried an especially high population burden in South Asians and Latin Americans. Isoform size was inversely associated with Lp(a) concentration, but did not significantly contribute to risk.

Clinical chemistry score versus high-sensitivity cardiac troponin I and T tests alone to identify patients at low or high risk for myocardial infarction or death at presentation to the emergency department

BACKGROUND

Testing for high-sensitivity cardiac troponin (hs-cTn) may assist triage and clinical decision-making in patients presenting to the emergency department with symptoms of acute coronary syndrome; however, this could result in the misclassification of risk because of analytical variation or laboratory error. We sought to evaluate a new laboratory-based risk-stratification tool that incorporates tests for hs-cTn, glucose level and estimated glomerular filtration rate to identify patients at risk of myocardial infarction or death when presenting to the emergency department.

METHODS

We constructed the clinical chemistry score (CCS) (range 0-5 points) and validated it as a predictor of 30-day myocardial infarction (MI) or death using data from 4 cohort studies involving patients who presented to the emergency department with symptoms suggestive of acute coronary syndrome. We calculated diagnostic parameters for the CCS score separately using high-sensitivity cardiac troponin I (hs-cTnI) and high-sensitivity cardiac troponin T (hs-cTnT).

RESULTS

For the combined cohorts (n = 4245), 17.1% of participants had an MI or died within 30 days. A CCS score of 0 points best identified low-risk participants: the hs-cTnI CCS had a sensitivity of 100% (95% confidence interval [CI] 99.5%-100%), with 8.9% (95% CI 8.1%-9.8%) of the population classified as being at low risk of MI or death within 30 days; the hs-cTnT CCS had a sensitivity of 99.9% (95% CI 99.2%-100%), with 10.5% (95% CI 9.6%-11.4%) of the population classified as being at low risk. The CCS had better sensitivity than hs-cTn alone (hs-cTnI < 5 ng/L: 96.6%, 95% CI 95.0%-97.8%; hs-cTnT < 6 ng/L: 98.2%, 95% CI 97.0%-99.0%). A CCS score of 5 points best identified patients at high risk (hs-cTnI CCS: specificity 96.6%, 95% CI 96.0%-97.2%; 11.2% [95% CI 10.3%-12.2%] of the population classified as being at high risk; hs-cTnT CCS: specificity 94.0%, 95% CI 93.1%-94.7%; 13.1% [95% CI 12.1%-14.1%] of the population classified as being at high risk) compared with using the overall 99th percentiles for the hs-cTn assays (specificity of hs-cTnI 93.2%, 95% CI 92.3-94.0; specificity of hs-cTnT 73.8%, 95% CI 72.3-75.2).

INTERPRETATION

The CCS score at the chosen cut-offs was more sensitive and specific than hs-cTn alone for risk stratification of patients presenting to the emergency department with suspected acute coronary syndrome. Study registration: ClinicalTrials.gov, nos. NCT01994577; NCT02355457.

Urinary sodium excretion, blood pressure, cardiovascular disease, and mortality: a community-level prospective epidemiological cohort study

BACKGROUND

WHO recommends that populations consume less than 2 g/day sodium as a preventive measure against cardiovascular disease, but this target has not been achieved in any country. This recommendation is primarily based on individual-level data from short-term trials of blood pressure (BP) without data relating low sodium intake to reduced cardiovascular events from randomised trials or observational studies. We investigated the associations between community-level mean sodium and potassium intake, cardiovascular disease, and mortality.

METHODS

The Prospective Urban Rural Epidemiology study is ongoing in 21 countries. Here we report an analysis done in 18 countries with data on clinical outcomes. Eligible participants were adults aged 35-70 years without cardiovascular disease, sampled from the general population. We used morning fasting urine to estimate 24 h sodium and potassium excretion as a surrogate for intake. We assessed community-level associations between sodium and potassium intake and BP in 369 communities (all >50 participants) and cardiovascular disease and mortality in 255 communities (all >100 participants), and used individual-level data to adjust for known confounders.

FINDINGS

95 767 participants in 369 communities were assessed for BP and 82 544 in 255 communities for cardiovascular outcomes with follow-up for a median of 8·1 years. 82 (80%) of 103 communities in China had a mean sodium intake greater than 5 g/day, whereas in other countries 224 (84%) of 266 communities had a mean intake of 3-5 g/day. Overall, mean systolic BP increased by 2·86 mm Hg per 1 g increase in mean sodium intake, but positive associations were only seen among the communities in the highest tertile of sodium intake (p<0·0001 for heterogeneity). The association between mean sodium intake and major cardiovascular events showed significant deviations from linearity (p=0·043) due to a significant inverse association in the lowest tertile of sodium intake (lowest tertile <4·43 g/day, mean intake 4·04 g/day, range 3·42-4·43; change -1·00 events per 1000 years, 95% CI -2·00 to -0·01, p=0·0497), no association in the middle tertile (middle tertile 4·43-5·08 g/day, mean intake 4·70 g/day, 4·44-5.05; change 0·24 events per 1000 years, -2·12 to 2·61, p=0·8391), and a positive but non-significant association in the highest tertile (highest tertile >5·08 g/day, mean intake 5·75 g/day, >5·08-7·49; change 0·37 events per 1000 years, -0·03 to 0·78, p=0·0712). A strong association was seen with stroke in China (mean sodium intake 5·58 g/day, 0·42 events per 1000 years, 95% CI 0·16 to 0·67, p=0·0020) compared with in other countries (4·49 g/day, -0·26 events, -0·46 to -0·06, p=0·0124; p<0·0001 for heterogeneity). All major cardiovascular outcomes decreased with increasing potassium intake in all countries.

INTERPRETATION

Sodium intake was associated with cardiovascular disease and strokes only in communities where mean intake was greater than 5 g/day. A strategy of sodium reduction in these communities and countries but not in others might be appropriate.

FUNDING

Population Health Research Institute, Canadian Institutes of Health Research, Canadian Institutes of Health Canada Strategy for Patient-Oriented Research, Ontario Ministry of Health and Long-Term Care, Heart and Stroke Foundation of Ontario, and European Research Council.

Performance of high-sensitivity cardiac troponin in the emergency department for myocardial infarction and a composite cardiac outcome across different estimated glomerular filtration rates

BACKGROUND

Clinicians regularly observe increased high-sensitivity cardiac troponin (hs-cTn) concentrations in patients with low estimated glomerular filtration rate (eGFR). The challenge is to differentiate acute coronary syndrome (ACS) from increased hs-cTn results across a range of eGFR. The objective of this study was to determined the optimal hs-cTn concentrations for acute myocardial infarction (MI) and a composite cardiovascular outcome across different eGFR ranges and to assess the utility of a low hs-cTn cutoff to rule-out events.

METHODS

We undertook an observational study in the emergency department of patients (n = 1212) with symptoms suggestive of ACS who had an eGFR and at least one Roche hs-cTnT and one Abbott hs-cTnI result. The 7-day outcomes were MI or a composite of MI, unstable angina, congestive heart failure, serious ventricular cardiac arrhythmia, or death. The maximum hs-cTn concentration was assessed across different eGFR ranges (<30,30-59,60-89,≥90 ml/min/1.73m²) by spearman correlation, ROC-curve analyses, and sensitivity and negative predictive value (NPV) for the proposed rule-out hs-cTn cutoffs (hs-cTnI<5 ng/l and hs-cTnT<6 ng/l) for the outcomes.

RESULTS

Both hs-cTnI and hs-cTnT concentrations were negatively correlated with eGFR. The lower the eGFR, the lower the AUC and the higher the optimal hs-cTn cutoffs for both MI and the composite outcome. The highest combined sensitivity (100%), NPV (100%) and proportion of low-risk for MI (45% of group) was observed for patients with hs-cTnT<6 ng/l with an eGFR≥90.

CONCLUSION

The test performance for hs-cTn for diagnosing or ruling-out an acute cardiac event varies per the eGFR. Accurate risk stratification requires knowledge of the eGFR.

High-sensitivity cardiac troponin concentrations at emergency department presentation in females and males with an acute cardiac outcome

Background There is interest in utilizing different cut-offs per sex for high-sensitivity cardiac troponin I (hs-cTnI) but less so for high-sensitivity cardiac troponin T (hs-cTnT) for patient management in the acute setting. Our objective was to assess if differences in hs-cTn concentrations exist between males and females for an acute cardiac outcome following the presentation measurement in the emergency department. Methods An observational emergency department population with hs-cTn measurements (Roche Diagnostics and Abbott Diagnostics) at presentation with seven-day outcomes for a composite acute cardiac outcome (i.e. myocardial infarction, unstable angina, ventricular arrhythmia, heart failure or cardiovascular death) (ClinicalTrials.gov: NCT01994577). Receiver operating characteristic curve analyses were performed for each sex with both hs-cTn assays. Results In those patients who had a composite acute cardiac outcome ( n = 128 females; n = 145 males), there was no difference in hs-cTn concentrations between the sexes (median [IQR] female hs-cTnT = 35 ng/L [21-69] vs. male hs-cTnT = 38 ng/L [19-77], P = 0.95; and median [IQR] female hs-cTnI = 27 ng/L [12-75] vs. male hs-cTnI = 26 ng/L [12-85], P = 0.97]. There was also no difference in the area under the curve between the hs-cTn assays and between the sexes ( P > 0.10). Comparing hs-cTn concentrations in those patients with the composite outcome between the sexes <60 years and ≥60 years of age also did not yield significant differences ( P > 0.70). Conclusions The concentrations and area under the curves of hs-cTnT and hs-cTnI at patient presentation in the emergency department for an acute composite cardiac outcome were similar between the sexes in this exploratory study.

Association of dietary nutrients with blood lipids and blood pressure in 18 countries: a cross-sectional analysis from the PURE study

BACKGROUND

The relation between dietary nutrients and cardiovascular disease risk markers in many regions worldwide is unknown. In this study, we investigated the effect of dietary nutrients on blood lipids and blood pressure, two of the most important risk factors for cardiovascular disease, in low-income, middle-income, and high-income countries.

METHODS

We studied 125 287 participants from 18 countries in North America, South America, Europe, Africa, and Asia in the Prospective Urban Rural Epidemiology (PURE) study. Habitual food intake was measured with validated food frequency questionnaires. We assessed the associations between nutrients (total fats, saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, carbohydrates, protein, and dietary cholesterol) and cardiovascular disease risk markers using multilevel modelling. The effect of isocaloric replacement of saturated fatty acids with other fats and carbohydrates was determined overall and by levels of intakes by use of nutrient density models. We did simulation modelling in which we assumed that the effects of saturated fatty acids on cardiovascular disease events was solely related to their association through an individual risk marker, and then compared these simulated risk marker-based estimates with directly observed associations of saturated fatty acids with cardiovascular disease events.

FINDINGS

Participants were enrolled into the study from Jan 1, 2003, to March 31, 2013. Intake of total fat and each type of fat was associated with higher concentrations of total cholesterol and LDL cholesterol, but also with higher HDL cholesterol and apolipoprotein A1 (ApoA1), and lower triglycerides, ratio of total cholesterol to HDL cholesterol, ratio of triglycerides to HDL cholesterol, and ratio of apolipoprotein B (ApoB) to ApoA1 (all p_trend<0·0001). Higher carbohydrate intake was associated with lower total cholesterol, LDL cholesterol, and ApoB, but also with lower HDL cholesterol and ApoA1, and higher triglycerides, ratio of total cholesterol to HDL cholesterol, ratio of triglycerides to HDL cholesterol, and ApoB-to-ApoA1 ratio (all p_trend<0·0001, apart from ApoB [p_trend=0·0014]). Higher intakes of total fat, saturated fatty acids, and carbohydrates were associated with higher blood pressure, whereas higher protein intake was associated with lower blood pressure. Replacement of saturated fatty acids with carbohydrates was associated with the most adverse effects on lipids, whereas replacement of saturated fatty acids with unsaturated fats improved some risk markers (LDL cholesterol and blood pressure), but seemed to worsen others (HDL cholesterol and triglycerides). The observed associations between saturated fatty acids and cardiovascular disease events were approximated by the simulated associations mediated through the effects on the ApoB-to-ApoA1 ratio, but not with other lipid markers including LDL cholesterol.

INTERPRETATION

Our data are at odds with current recommendations to reduce total fat and saturated fats. Reducing saturated fatty acid intake and replacing it with carbohydrate has an adverse effect on blood lipids. Substituting saturated fatty acids with unsaturated fats might improve some risk markers, but might worsen others. Simulations suggest that ApoB-to-ApoA1 ratio probably provides the best overall indication of the effect of saturated fatty acids on cardiovascular disease risk among the markers tested. Focusing on a single lipid marker such as LDL cholesterol alone does not capture the net clinical effects of nutrients on cardiovascular risk.

FUNDING

Full funding sources listed at the end of the paper (see Acknowledgments).

Consensus approach to nasal high-flow therapy in neonates

OBJECTIVE

Nasal high-flow therapy (nHFT) is commonly used for noninvasive respiratory support in the neonatal intensive care unit. Our objective was to determine which aspects of neonatal nHFT have achieved adequate evidence base to support consensus among experienced clinical investigators, and to document areas lacking consensus to promote future investigations.

STUDY DESIGN

Prospective, modified Delphi collation of tabular queries related to specific aspects of neonatal nHFT. Seven international nHFT clinical researchers were queried regarding approaches to initiation, escalation, weaning and discontinuing nHFT. Completed tables were reviewed independently by each investigator, results clarified and discussed and areas of consensus determined.

RESULTS

Consensus agreement was reached for many aspects of nHFT including: need for adequate heating and humidification, need to prevent nares occlusion, maximum flow rate of 8 l min^-1, assessment of fraction of inspired oxygen (FiO₂) and work of breathing for either flow escalation or weaning, equivalence of nHFT to nasal continuous positive airway pressure (nCPAP) for noninvasive support of infants of ⩾28 weeks with resolving respiratory distress and use of nHFT for noninvasive support of stable infants on nCPAP. There was general agreement for initial gas flow rates in the range of 4 to 6 l min^-1 and for nHFT as primary therapy for mild respiratory distress. There was no consensus on the approach to discontinuing nHFT.

CONCLUSIONS

Among an experienced group of nHFT clinical researchers, there was general consensus in the approach to neonatal nHFT. Additional randomized studies are indicated to provide better evidence related to several aspects of nHFT, as well as to identify other clinical conditions where nHFT may provide safe, effective noninvasive support.

Growth Differentiation Factor 15 as a Novel Biomarker for Metformin

OBJECTIVE

Metformin is a commonly used glucose-lowering drug. However, apart from glycemic measures, no biomarker for its presence or dose has been identified.

RESEARCH DESIGN AND METHODS

A total of 237 biomarkers were assayed in baseline serum from 8,401 participants (2,317 receiving metformin) in the Outcome Reduction with Initial Glargine Intervention (ORIGIN) trial. Regression models were used to identify biomarkers for metformin use.

RESULTS

Growth differentiation factor 15 (GDF15) was strongly linked to metformin, such that the odds of metformin use per SD increase in level varied from 3.73 (95% CI 3.40, 4.09) to 3.94 (95% CI 3.59, 4.33) depending on the other included variables. For the remaining 25 linked biomarkers, the odds ranged from 0.71 to 1.24. A 1.64 ng/mL higher GDF15 level predicted a 188-mg higher metformin dose (P < 0.0001).

CONCLUSIONS

GDF15 levels are a biomarker for the use of metformin in people with dysglycemia, and its concentration reflects the dose of metformin.

Rule-In and Rule-Out of Myocardial Infarction Using Cardiac Troponin and Glycemic Biomarkers in Patients with Symptoms Suggestive of Acute Coronary Syndrome

BACKGROUND

Early rule-in/rule-out of myocardial infarction (MI) in patients presenting to the emergency department (ED) is important for patient care and resource allocation. Given that dysglycemia is a strong risk factor for MI, we sought to explore and compare different combinations of cardiac troponin (cTn) cutoffs with glycemic markers for the early rule-in/rule-out of MI.

METHODS

We included ED patients (n = 1137) with symptoms suggestive of acute coronary syndrome (ACS) who had cTnI, high-sensitivity cTnI (hs-cTnI), hs-cTnT, glucose, and hemoglobin A_1c (Hb A_1c) measurements. We derived rule-in/rule-out algorithms using different combinations of ROC-derived and literature cutoffs for rule-in and rule-out of MI within 7 days after presentation. These algorithms were then tested for MI/cardiovascular death and ACS/cardiovascular death at 7 days. ROC curves, sensitivity, specificity, likelihood ratios, positive and negative predictive values (PPV and NPV), and CIs were determined for various biomarker combinations.

RESULTS

MI was diagnosed in 133 patients (11.7%; 95% CI, 9.8-13.8). The algorithms that included cTn and glucose produced the greatest number of patients ruled out/ruled in for MI and yielded sensitivity ≥99%, NPV ≥99.5%, specificity ≥99%, and PPV ≥80%. This diagnostic performance was maintained for MI/cardiovascular death but not for ACS/cardiovascular death. The addition of hemoglobin A_1c (Hb A_1c) (≥6.5%) to these algorithms did not change these estimates; however, 50 patients with previously unknown diabetes may have been identified if Hb A_1c was measured.

CONCLUSIONS

Algorithms incorporating glucose with cTn may lead to an earlier MI diagnosis and rule-out for MI/cardiovascular death. Addition of Hb A_1c into these algorithms allows for identification of diabetes. Future studies extending these findings are needed for ACS/cardiovascular death. ClinicalTrials.gov identifier: NCT01994577.

Economic Considerations of Early Rule-In/Rule-Out Algorithms for The Diagnosis of Myocardial Infarction in The Emergency Department Using Cardiac Troponin and Glycemic Biomarkers

BACKGROUND

We have previously demonstrated the utility of a rule-in/rule-out strategy for myocardial infarction (MI) using glycemic biomarkers in combination with cardiac troponin in the emergency department (ED). Given that the cost of assessing patients with possible MI in the ED is increasing, we sought to compare the health services cost of our previously identified early rule-in/rule-out approaches for MI among patients who present to the ED with symptoms suggestive of acute coronary syndrome (ACS).

METHODS

We compared the cost differences between different rule-in/rule-out strategies for MI using presentation cardiac troponin I (cTnI), high-sensitivity cTnI (hs-cTnI), high-sensitivity cardiac troponin T (hs-cTnT), glucose, and/or hemoglobin A_1c (Hb A_1c) in 1137 ED patients (7-day MI n = 133) as per our previously defined algorithms and compared them with the European Society of Cardiology (ESC) 0-h algorithm-cutoffs. Costs associated with each decision model were obtained from site-specific sources (length of stay) and provincial sources (Ontario Case Costing Initiative).

RESULTS

Algorithms incorporating cardiac troponin and glucose for early rule-in/rule-out were the most cost effective and clinically safest methods (i.e., ≤1 MI missed) for early decision making, with hs-cTnI and glucose yielding lower costs compared to cTnI and glucose, despite the higher price for the hs-cTnI test. The addition of Hb A_1c to the algorithms increased the cost of these algorithms but did not miss any additional patients with MI. Applying the ESC 0-h algorithm-cutoffs for hs-cTnI and hs-cTnT were the most costly.

CONCLUSIONS

Rule-in/rule-out algorithms incorporating presentation glucose with high-sensitivity cardiac troponin are the safest and most cost-effective options as compared to the ESC 0-h algorithm-cutoffs.

Age and Cardiovascular Risk Attributable to Apolipoprotein B, Low-Density Lipoprotein Cholesterol or Non-High-Density Lipoprotein Cholesterol

Background

Higher concentrations of the apolipoprotein B (apoB) lipoproteins increase the risk of cardiovascular disease. However, whether the risk associated with apoB lipoproteins varies with age has not been well examined.

Methods and Results

We determined the associations for total cholesterol, low‐density lipoprotein (LDL)‐cholesterol (LDL‐C), non‐high‐density lipoprotein‐cholesterol (non‐HDL‐C), apoB, apolipoprotein A‐I (apoA‐I), and HDL‐cholesterol (HDL‐C) with myocardial infarction at different ages in 11 760 controls and 8998 myocardial infarction cases of the INTERHEART Study. Logistic regression was used to compute the odds ratio of myocardial infarction for 1 SD change in each lipid marker by decade from <40 to >70 years of age. Except for those >70, plasma levels of total cholesterol, LDL‐C, and non‐HDL‐C and apoB were greater in cases than controls. However, the average levels of these markers decreased significantly as age increased. By contrast, levels of apoA‐I and HDL‐C were significantly greater in controls than cases but increased significantly as age increased. The cardiovascular risk associated with the atherogenic lipid markers differed at different ages. Most notably, there was a significant decline in the odds ratio for total cholesterol, LDL‐C, and non‐HDL‐C, and apoB with increases in age whereas the odds ratios associated with apoA‐I and HDL‐C were consistent across the age groups.

Conclusions

These data indicate that the risk of cardiovascular events associated with apoB particles is greater in younger compared to older individuals. This finding is consistent with greater relative benefit from LDL‐lowering therapy in younger compared to older individuals and so argues for therapy in younger individuals with elevated lipids.

Associations of urinary sodium excretion with cardiovascular events in individuals with and without hypertension: a pooled analysis of data from four studies

BACKGROUND

Several studies reported a U-shaped association between urinary sodium excretion and cardiovascular disease events and mortality. Whether these associations vary between those individuals with and without hypertension is uncertain. We aimed to explore whether the association between sodium intake and cardiovascular disease events and all-cause mortality is modified by hypertension status.

METHODS

In this pooled analysis, we studied 133,118 individuals (63,559 with hypertension and 69,559 without hypertension), median age of 55 years (IQR 45-63), from 49 countries in four large prospective studies and estimated 24-h urinary sodium excretion (as group-level measure of intake). We related this to the composite outcome of death and major cardiovascular disease events over a median of 4.2 years (IQR 3.0-5.0) and blood pressure.

FINDINGS

Increased sodium intake was associated with greater increases in systolic blood pressure in individuals with hypertension (2.08 mm Hg change per g sodium increase) compared with individuals without hypertension (1.22 mm Hg change per g; pinteraction<0.0001). In those individuals with hypertension (6835 events), sodium excretion of 7 g/day or more (7060 [11%] of population with hypertension: hazard ratio [HR] 1.23 [95% CI 1.11-1.37]; p<0.0001) and less than 3 g/day (7006 [11%] of population with hypertension: 1.34 [1.23-1.47]; p<0.0001) were both associated with increased risk compared with sodium excretion of 4-5 g/day (reference 25% of the population with hypertension). In those individuals without hypertension (3021 events), compared with 4-5 g/day (18,508 [27%] of the population without hypertension), higher sodium excretion was not associated with risk of the primary composite outcome (≥ 7 g/day in 6271 [9%] of the population without hypertension; HR 0.90 [95% CI 0.76-1.08]; p=0.2547), whereas an excretion of less than 3 g/day was associated with a significantly increased risk (7547 [11%] of the population without hypertension; HR 1.26 [95% CI 1.10-1.45]; p=0.0009).

INTERPRETATION

Compared with moderate sodium intake, high sodium intake is associated with an increased risk of cardiovascular events and death in hypertensive populations (no association in normotensive population), while the association of low sodium intake with increased risk of cardiovascular events and death is observed in those with or without hypertension. These data suggest that lowering sodium intake is best targeted at populations with hypertension who consume high sodium diets.

FUNDING

Full funding sources listed at end of paper (see Acknowledgments).

Variations in Diabetes Prevalence in Low-, Middle-, and High-Income Countries: Results From the Prospective Urban and Rural Epidemiological Study

OBJECTIVE

The goal of this study was to assess whether diabetes prevalence varies by countries at different economic levels and whether this can be explained by known risk factors.

RESEARCH DESIGN AND METHODS

The prevalence of diabetes, defined as self-reported or fasting glycemia ≥7 mmol/L, was documented in 119,666 adults from three high-income (HIC), seven upper-middle-income (UMIC), four lower-middle-income (LMIC), and four low-income (LIC) countries. Relationships between diabetes and its risk factors within these country groupings were assessed using multivariable analyses.

RESULTS

Age- and sex-adjusted diabetes prevalences were highest in the poorer countries and lowest in the wealthiest countries (LIC 12.3%, UMIC 11.1%, LMIC 8.7%, and HIC 6.6%; P < 0.0001). In the overall population, diabetes risk was higher with a 5-year increase in age (odds ratio 1.29 [95% CI 1.28-1.31]), male sex (1.19 [1.13-1.25]), urban residency (1.24 [1.11-1.38]), low versus high education level (1.10 [1.02-1.19]), low versus high physical activity (1.28 [1.20-1.38]), family history of diabetes (3.15 [3.00-3.31]), higher waist-to-hip ratio (highest vs. lowest quartile; 3.63 [3.33-3.96]), and BMI (≥35 vs. <25 kg/m(2); 2.76 [2.52-3.03]). The relationship between diabetes prevalence and both BMI and family history of diabetes differed in higher- versus lower-income country groups (P for interaction < 0.0001). After adjustment for all risk factors and ethnicity, diabetes prevalences continued to show a gradient (LIC 14.0%, LMIC 10.1%, UMIC 10.9%, and HIC 5.6%).

CONCLUSIONS

Conventional risk factors do not fully account for the higher prevalence of diabetes in LIC countries. These findings suggest that other factors are responsible for the higher prevalence of diabetes in LIC countries.

Mortality and morbidity in relation to changes in albuminuria, glucose status and systolic blood pressure: an analysis of the ONTARGET and TRANSCEND studies

AIMS/HYPOTHESIS

Urinary albumin excretion is a strong predictor of cardiovascular disease. It is uncertain whether improvement from microalbuminuria or deterioration from normoalbuminuria over time in patients with differing changes in glucose and BP change their cardiovascular risk.

METHODS

Data on mortality, cardiovascular and renal outcomes were analysed in 22,984 patients from two large parallel randomised clinical trials followed for 56 months. A central laboratory analysed first morning spot urine samples at baseline and after 24 months, and events were recorded over the subsequent 32 months. Patients were stratified by changes in albuminuria, glucose status and mean systolic BP over 2 years.

RESULTS

There was a strong association between albuminuria status and all-cause and cardiovascular mortality and combined cardiovascular and renal endpoints (all p < 0.0001). Changes in systolic BP control had no effect on mortality, whereas glucose status was significantly associated with all outcomes. Irrespective of BP control or glucose status, patients showing an improvement from microalbuminuria to normoalbuminuria after 2 years were at a lower risk of all outcome measures than patients showing deterioration from normoalbuminuria to microalbuminuria (HR for all-cause mortality 0.65 [0.52-0.83], p = 0.0004).

CONCLUSIONS/INTERPRETATION

Patients who showed improvement to normoalbuminuria over 2 years were at lower risk of all-cause and cardiovascular mortality and of cardiovascular and renal events than those who deteriorated to microalbuminuria over time. Albuminuria over time was significantly better than glucose status and BP control in predicting mortality and both cardiovascular and renal outcomes in patients at a high cardiovascular risk.

Cardiovascular risk and events in 17 low-, middle-, and high-income countries

BACKGROUND

More than 80% of deaths from cardiovascular disease are estimated to occur in low-income and middle-income countries, but the reasons are unknown.

METHODS

We enrolled 156,424 persons from 628 urban and rural communities in 17 countries (3 high-income, 10 middle-income, and 4 low-income countries) and assessed their cardiovascular risk using the INTERHEART Risk Score, a validated score for quantifying risk-factor burden without the use of laboratory testing (with higher scores indicating greater risk-factor burden). Participants were followed for incident cardiovascular disease and death for a mean of 4.1 years.

RESULTS

The mean INTERHEART Risk Score was highest in high-income countries, intermediate in middle-income countries, and lowest in low-income countries (P<0.001). However, the rates of major cardiovascular events (death from cardiovascular causes, myocardial infarction, stroke, or heart failure) were lower in high-income countries than in middle- and low-income countries (3.99 events per 1000 person-years vs. 5.38 and 6.43 events per 1000 person-years, respectively; P<0.001). Case fatality rates were also lowest in high-income countries (6.5%, 15.9%, and 17.3% in high-, middle-, and low-income countries, respectively; P=0.01). Urban communities had a higher risk-factor burden than rural communities but lower rates of cardiovascular events (4.83 vs. 6.25 events per 1000 person-years, P<0.001) and case fatality rates (13.52% vs. 17.25%, P<0.001). The use of preventive medications and revascularization procedures was significantly more common in high-income countries than in middle- or low-income countries (P<0.001).

CONCLUSIONS

Although the risk-factor burden was lowest in low-income countries, the rates of major cardiovascular disease and death were substantially higher in low-income countries than in high-income countries. The high burden of risk factors in high-income countries may have been mitigated by better control of risk factors and more frequent use of proven pharmacologic therapies and revascularization. (Funded by the Population Health Research Institute and others.).

Battery of behavioral tests in mice that models age-associated changes in human motor function

Motor function in humans can be characterized with tests of locomotion, strength, balance, and endurance. The aim of our project was to establish an analogous test battery to assess motor function in mice. Male C57BL/6 mice were studied at 3 (n = 87), 20 (n = 48) and 26 (n = 43) months of age. Tests assessed locomotion, strength, balance/coordination, and endurance capacity in mice. Motor function was reduced in the older groups of mice for the locomotion, strength, and endurance subdomains (p < 0.001). As indicated with a summary score, motor function declined by 7.4 % from 3 to 20 months and by 13.5 % from 20 to 26 months. Based on comparison with previously published data in humans, the magnitude and relative time course of changes were similar in mice and humans in each subdomain except balance/coordination. Power calculations confirmed that the age-associated differences depicted by several of the individual tests and domain summary scores would be sufficient to assess the efficacy of interventions aimed at prevention or treatment of motor dysfunction with aging. The current study describes a mouse model that characterizes age-associated changes in clinically relevant domains of motor function and indicates that the preclinical model can be used to test strategies to attenuate age-associated declines in motor function.

Urinary sodium and potassium excretion and risk of cardiovascular events

CONTEXT

The precise relationship between sodium and potassium intake and cardiovascular (CV) risk remains uncertain, especially in patients with CV disease.

OBJECTIVE

To determine the association between estimated urinary sodium and potassium excretion (surrogates for intake) and CV events in patients with established CV disease or diabetes mellitus.

DESIGN, SETTING, AND PATIENTS

Observational analyses of 2 cohorts (N = 28,880) included in the ONTARGET and TRANSCEND trials (November 2001-March 2008 from initial recruitment to final follow-up). We estimated 24-hour urinary sodium and potassium excretion from a morning fasting urine sample (Kawasaki formula). We used restricted cubic spline plots to describe the association between sodium and potassium excretion and CV events and mortality, and to identify reference categories for sodium and potassium excretion. We used Cox proportional hazards multivariable models to determine the association of urinary sodium and potassium with CV events and mortality.

MAIN OUTCOME MEASURES

CV death, myocardial infarction (MI), stroke, and hospitalization for congestive heart failure (CHF).

RESULTS

At baseline, the mean (SD) estimated 24-hour excretion for sodium was 4.77 g (1.61); and for potassium was 2.19 g (0.57). After a median follow-up of 56 months, the composite outcome occurred in 4729 (16.4%) participants, including 2057 CV deaths, 1412 with MI, 1282 with stroke, and 1213 with hospitalization for CHF. Compared with the reference group with estimated baseline sodium excretion of 4 to 5.99 g per day (n = 14,156; 6.3% participants with CV death, 4.6% with MI, 4.2% with stroke, and 3.8% admitted to hospital with CHF), higher baseline sodium excretion was associated with an increased risk of CV death (9.7% for 7-8 g/day; hazard ratio [HR], 1.53; 95% CI, 1.26-1.86; and 11.2% for >8 g/day; HR, 1.66; 95% CI, 1.31-2.10), MI (6.8%; HR, 1.48; 95% CI, 1.11-1.98 for >8 g/day), stroke (6.6%; HR, 1.48; 95% CI, 1.09-2.01 for >8 g/day), and hospitalization for CHF (6.5%; HR, 1.51; 1.12-2.05 for >8 g/day). Lower sodium excretion was associated with an increased risk of CV death (8.6%; HR, 1.19; 95% CI, 1.02-1.39 for 2-2.99 g/day; 10.6%; HR, 1.37; 95% CI, 1.09-1.73 for <2 g/day), and hospitalization for CHF (5.2%; HR, 1.23; 95% CI, 1.01-1.49 for 2-2.99 g/day) on multivariable analysis. Compared with an estimated potassium excretion of less than 1.5 g per day (n = 2194; 6.2% with stroke), higher potassium excretion was associated with a reduced risk of stroke (4.7% [HR, 0.77; 95% CI, 0.63-0.94] for 1.5-1.99 g/day; 4.3% [HR, 0.73; 95% CI, 0.59-0.90] for 2-2.49 g/day; 3.9% [HR, 0.71; 95% CI, 0.56-0.91] for 2.5-3 g/day; and 3.5% [HR, 0.68; 95% CI, 0.49-0.92] for >3 g/day) on multivariable analysis.

CONCLUSIONS

The association between estimated sodium excretion and CV events was J-shaped. Compared with baseline sodium excretion of 4 to 5.99 g per day, sodium excretion of greater than 7 g per day was associated with an increased risk of all CV events, and a sodium excretion of less than 3 g per day was associated with increased risk of CV mortality and hospitalization for CHF. Higher estimated potassium excretion was associated with a reduced risk of stroke.

Changes in albuminuria predict mortality and morbidity in patients with vascular disease

The degree of albuminuria predicts cardiovascular and renal outcomes, but it is not known whether changes in albuminuria also predict similar outcomes. In two multicenter, multinational, prospective observational studies, a central laboratory measured albuminuria in 23,480 patients with vascular disease or high-risk diabetes. We quantified the association between a greater than or equal to twofold change in albuminuria in spot urine from baseline to 2 years and the incidence of cardiovascular and renal outcomes and all-cause mortality during the subsequent 32 months. A greater than or equal to twofold increase in albuminuria from baseline to 2 years, observed in 28%, associated with nearly 50% higher mortality (HR 1.48; 95% CI 1.32 to 1.66), and a greater than or equal to twofold decrease in albuminuria, observed in 21%, associated with 15% lower mortality (HR 0.85; 95% CI 0.74 to 0.98) compared with those with lesser changes in albuminuria, after adjustment for baseline albuminuria, BP, and other potential confounders. Increases in albuminuria also significantly associated with cardiovascular death, composite cardiovascular outcomes (cardiovascular death, myocardial infarction, stroke, and hospitalization for heart failure), and renal outcomes including dialysis or doubling of serum creatinine (adjusted HR 1.40; 95% CI 1.11 to 1.78). In conclusion, in patients with vascular disease, changes in albuminuria predict mortality and cardiovascular and renal outcomes, independent of baseline albuminuria. This suggests that monitoring albuminuria is a useful strategy to help predict cardiovascular risk.

Cardiovascular and renal outcomes with telmisartan, ramipril, or both in people at high renal risk: results from the ONTARGET and TRANSCEND studies

BACKGROUND

In the Ongoing Telmisartan Alone and in Combination With Ramipril Global End Point Trial (ONTARGET), dual therapy did not reduce cardiovascular or renal outcomes compared with either angiotensin-converting enzyme inhibitors or angiotensin receptor blockers alone. Previous controlled trials with angiotensin-converting enzyme inhibitors or angiotensin receptor blockers have demonstrated greater cardiovascular and renal benefit in people with renal risk. We hypothesized that dual therapy would be more effective than monotherapy in patients with low glomerular filtration rate and elevated albuminuria.

METHODS AND RESULTS

Post hoc analysis was performed of renal subgroups of dual therapy versus monotherapy for the ONTARGET study and angiotensin receptor blocker versus placebo for the Telmisartan Randomized Assessment Study in ACE Intolerant Subjects With Cardiovascular Disease (TRANSCEND). The studies featured hazard ratios by subgroups and Cox regression models with factors for treatment, subgroup, and interactions. The main cardiovascular outcome was the composite of cardiovascular death, myocardial infarction, stroke, or hospitalization for heart failure, and the main renal outcome was the composite of chronic dialysis or doubling of creatinine. In ONTARGET, there was no cardiovascular or renal benefit from dual over monotherapy in any subgroup, even with low glomerular filtration rate and/or elevated albuminuria. In TRANSCEND, in the comparison of angiotensin receptor blocker with placebo, there was a significant interaction for the main renal outcome (P = 0.01) in the direction of harm for patients with normoalbuminuria (0.37 versus 0.16 events per 100 patient-years; hazard ratio, 2.35; confidence interval, 1.33 to 4.15) but a trend to benefit with microalbuminuria (0.52 versus 0.89 events per 100 patient-years; hazard ratio, 0.60; confidence interval, 0.25 to 1.46) and macroalbuminuria (1.57 versus 2.60 events per 100 patient-years; hazard ratio, 0.71; confidence interval, 0.21 to 2.44).

CONCLUSIONS

This post hoc analysis does not support dual therapy over monotherapy in high-vascular risk patients with low glomerular filtration rate or albuminuria. This observation is a post hoc comparison and should be interpreted appropriately.

CLINICAL TRIAL REGISTRATION

URL: http://clinicaltrials.gov Identifier: NCT00153101.

Dysglycaemia and the risk of acute myocardial infarction in multiple ethnic groups: an analysis of 15,780 patients from the INTERHEART study

AIMS/HYPOTHESIS

Although diabetes is an established risk factor for myocardial infarction (MI), disease control may vary. HbA(1c) is a reliable index of ambient glucose levels and may provide more information on MI risk than diabetes status.

METHODS

The relationship between HbA(1c) levels in MI patients and controls who participated in the 52 country INTERHEART study was analysed.

RESULTS

In 15,780 participants with a HbA(1c) value (1,993 of whom had diabetes), the mean (SD) levels for HbA(1c) were 6.15% (1.10) in the 6,761 MI patients and 5.85% (0.80) in the control participants. After adjustment for age, sex and nine major MI risk factors (including diabetes), higher HbA(1c) fifths above the lowest fifth (HbA(1c) <5.4%) were associated with progressively higher OR of MI, with OR for the highest HbA(1c) fifth (≥ 6.12%) being 1.55 (95% CI 1.37-1.75). When analysed as a continuous variable after adjustment for the same factors, every 1% higher HbA(1c) value was associated with 19% (95% CI 14-23) higher odds of MI, while every 0.5% higher HbA(1c) was associated with 9% higher odds of MI (95% CI 7-11). Concordant relationships were noted across subgroups, with a higher OR noted in younger people, patients without diabetes or hypertension, and those from some regions and ethnicities.

CONCLUSIONS/INTERPRETATION

The HbA(1c) value provides more information on MI odds than self-reported diabetes status or many other established risk factors. Every 1% increment independently predicts a 19% higher odds of MI after accounting for other MI risk factors including diabetes.

Is a pre-operative brain natriuretic peptide or N-terminal pro-B-type natriuretic peptide measurement an independent predictor of adverse cardiovascular outcomes within 30 days of noncardiac surgery? A systematic review and meta-analysis of observational studies

OBJECTIVES

We conducted a systematic review and meta-analysis to determine if pre-operative brain natriuretic peptide (BNP) (i.e., BNP or N-terminal pro-B-type natriuretic peptide [NT-proBNP]) is an independent predictor of 30-day adverse cardiovascular outcomes after noncardiac surgery.

BACKGROUND

Pre-operative clinical cardiac risk indices have only modest predictive power. BNP predicts adverse cardiovascular outcomes in a variety of nonsurgical settings and may similarly predict these outcomes in the perioperative setting.

METHODS

We employed 5 search strategies (e.g., searching bibliographic databases), and we included all studies that assessed the independent prognostic value of pre-operative BNP measurement as a predictor of cardiovascular complications after noncardiac surgery. We determined study eligibility and conducted data abstraction independently and in duplicate. We calculated a pooled odds ratio using a random effects model.

RESULTS

Nine studies met eligibility criteria, and included a total of 3,281 patients, among whom 314 experienced 1 or more perioperative cardiovascular complications. The average proportion of patients with elevated BNP was 24.8% (95% confidence interval [CI]: 20.1 to 30.4%; I(2) = 89%). All studies showed a statistically significant association between an elevated pre-operative BNP level and various cardiovascular outcomes (e.g., a composite of cardiac death and nonfatal myocardial infarction; atrial fibrillation). Data pooled from 7 studies demonstrated an odds ratio (OR) of 19.3 (95% CI: 8.5 to 43.7; I(2) = 58%). The pre-operative BNP measurement was an independent predictor of perioperative cardiovascular events among studies that only considered the outcomes of death, cardiovascular death, or myocardial infarction (OR: 44.2, 95% CI: 7.6 to 257.0, I(2) = 51.6%), and those that included other outcomes (OR: 14.7, 95% CI: 5.7 to 38.2, I(2) = 62.2%); the p value for interaction was 0.28.

CONCLUSIONS

These results suggest that an elevated pre-operative BNP or NT-proBNP measurement is a powerful, independent predictor of cardiovascular events in the first 30 days after noncardiac surgery.

Homocysteine-Lowering Therapy and Stroke Risk, Severity, and Disability

Background and Purpose— Elevated total homocysteine is associated with a higher risk of cerebrovascular disease. It is not known whether lowering homocysteine impacts on stroke risk, both in terms of severity and ischemic vs hemorrhagic stroke subtypes. Our aim was to determine whether vitamin therapy reduces the risk of ischemic and hemorrhagic stroke, as well as stroke-related disability.

Methods— We analyzed stroke outcomes among participants of the Heart Outcomes Prevention Evaluation 2 (HOPE 2) trial that randomized 5522 adults with known cardiovascular disease to a daily combination of 2.5 mg of folic acid, 50 mg of vitamin B6, and 1 mg of vitamin B12, or matching placebo, for 5 years.

Results— Among 5522 participants, stroke occurred in 258 (4.7%) individuals during a mean of 5 years of follow-up. The geometric mean homocysteine concentration decreased by 2.2 μmol/L in the vitamin therapy group and increased by 0.80 μmol/L in the placebo group. The incidence rate of stroke was 0.88 per 100 person-years in the vitamin therapy group and 1.15 per 100 person-years in the placebo group (hazard ratio [HR], 0.75; 95% CI, 0.59–0.97). Vitamin therapy also reduced the risk of nonfatal stroke (HR, 0.72; 95% CI, 0.54–0.95) but did not impact on neurological deficit at 24 hours ( P =0.45) or functional dependence at discharge or at 7 days (OR, 0.95; 95% CI, 0.57–1.56). In subgroup analysis, patients aged younger than 69 years, from regions without folic acid food fortification, with higher baseline cholesterol and homocysteine levels, and those not receiving antiplatelet or lipid-lowering drugs at enrollment had a larger treatment benefit.

Conclusions— Lowering of homocysteine with folic acid and vitamins B6 and B12 did reduce the risk of overall stroke, but not stroke severity or disability.

Renal outcomes with telmisartan, ramipril, or both, in people at high vascular risk (the ONTARGET study): a multicentre, randomised, double-blind, controlled trial

BACKGROUND

Angiotensin receptor blockers (ARB) and angiotensin converting enzyme (ACE) inhibitors are known to reduce proteinuria. Their combination might be more effective than either treatment alone, but long-term data for comparative changes in renal function are not available. We investigated the renal effects of ramipril (an ACE inhibitor), telmisartan (an ARB), and their combination in patients aged 55 years or older with established atherosclerotic vascular disease or with diabetes with end-organ damage.

METHODS

The trial ran from 2001 to 2007. After a 3-week run-in period, 25 620 participants were randomly assigned to ramipril 10 mg a day (n=8576), telmisartan 80 mg a day (n=8542), or to a combination of both drugs (n=8502; median follow-up was 56 months), and renal function and proteinuria were measured. The primary renal outcome was a composite of dialysis, doubling of serum creatinine, and death. Analysis was by intention to treat. This study is registered with ClinicalTrials.gov, number NCT00153101.

FINDINGS

784 patients permanently discontinued randomised therapy during the trial because of hypotensive symptoms (406 on combination therapy, 149 on ramipril, and 229 on telmisartan). The number of events for the composite primary outcome was similar for telmisartan (n=1147 [13.4%]) and ramipril (1150 [13.5%]; hazard ratio [HR] 1.00, 95% CI 0.92-1.09), but was increased with combination therapy (1233 [14.5%]; HR 1.09, 1.01-1.18, p=0.037). The secondary renal outcome, dialysis or doubling of serum creatinine, was similar with telmisartan (189 [2.21%]) and ramipril (174 [2.03%]; HR 1.09, 0.89-1.34) and more frequent with combination therapy (212 [2.49%]: HR 1.24, 1.01-1.51, p=0.038). Estimated glomerular filtration rate (eGFR) declined least with ramipril compared with telmisartan (-2.82 [SD 17.2] mL/min/1.73 m(2)vs -4.12 [17.4], p<0.0001) or combination therapy (-6.11 [17.9], p<0.0001). The increase in urinary albumin excretion was less with telmisartan (p=0.004) or with combination therapy (p=0.001) than with ramipril.

INTERPRETATION

In people at high vascular risk, telmisartan's effects on major renal outcomes are similar to ramipril. Although combination therapy reduces proteinuria to a greater extent than monotherapy, overall it worsens major renal outcomes.

Effects of ramipril and rosiglitazone on cardiovascular and renal outcomes in people with impaired glucose tolerance or impaired fasting glucose: results of the Diabetes REduction Assessment with ramipril and rosiglitazone Medication (DREAM) trial

OBJECTIVE

Impaired glucose tolerance (IGT) and/or impaired fasting glucose (IFG) are risk factors for diabetes, cardiovascular disease (CVD), and kidney disease. We determined the effects of ramipril and rosiglitazone on combined and individual CVD and renal outcomes in people with IGT and/or IFG in the Diabetes REduction Assessment With ramipril and rosiglitazone Medication (DREAM) trial.

RESEARCH DESIGN AND METHODS

A total of 5,269 people aged >or=30 years, with IGT and/or IFG without known CVD or renal insufficiency, were randomized to 15 mg/day ramipril versus placebo and 8 mg/day rosiglitazone versus placebo. A composite cardiorenal outcome and its CVD and renal components were assessed during the 3-year follow-up.

RESULTS

Compared with placebo, neither ramipril (15.7% [412 of 2,623] vs. 16.0% [424 of 2,646]; hazard ratio [HR] 0.98 [95% CI 0.84-1.13]; P = 0.75) nor rosiglitazone (15.0% [394 of 2,635] vs. 16.8% [442 of 2,634]; 0.87 [0.75-1.01]; P = 0.07) reduced the risk of the cardiorenal composite outcome. Ramipril had no impact on the CVD and renal components. Rosiglitazone increased heart failure (0.53 vs. 0.08%; HR 7.04 [95% CI 1.60-31.0]; P = 0.01) but reduced the risk of the renal component (0.80 [0.68-0.93]; P = 0.005); prevention of diabetes was independently associated with prevention of the renal component (P < 0.001).

CONCLUSIONS

Ramipril did not alter the cardiorenal outcome or its components. Rosiglitazone, which reduced diabetes, also reduced the development of renal disease but not the cardiorenal outcome and increased the risk of heart failure.

Defining obesity cut points in a multiethnic population

BACKGROUND

Body mass index (BMI) is widely used to assess risk for cardiovascular disease and type 2 diabetes. Cut points for the classification of obesity (BMI >30 kg/m2) have been developed and validated among people of European descent. It is unknown whether these cut points are appropriate for non-European populations. We assessed the metabolic risk associated with BMI among South Asians, Chinese, Aboriginals, and Europeans.

METHODS AND RESULTS

We randomly sampled 1078 subjects from 4 ethnic groups (289 South Asians, 281 Chinese, 207 Aboriginals, and 301 Europeans) from 4 regions in Canada. Principal components factor analysis was used to derive underlying latent or "hidden" factors associated with 14 clinical and biochemical cardiometabolic markers. Ethnic-specific BMI cut points were derived for 3 cardiometabolic factors. Three primary latent factors emerged that accounted for 56% of the variation in markers of glucose metabolism, lipid metabolism, and blood pressure. For a given BMI, elevated levels of glucose- and lipid-related factors were more likely to be present in South Asians, Chinese, and Aboriginals compared with Europeans, and elevated levels of the blood pressure-related factor were more likely to be present among Chinese compared with Europeans. The cut point to define obesity, as defined by distribution of glucose and lipid factors, is lower by approximately 6 kg/m2 among non-European groups compared with Europeans.

CONCLUSIONS

Revisions may be warranted for BMI cut points to define obesity among South Asians, Chinese, and Aboriginals. Using these revised cut points would greatly increase the estimated burden of obesity-related metabolic disorders among non-European populations.

Testing for BNP and NT-proBNP in the diagnosis and prognosis of heart failure

OBJECTIVES

The purpose of this systematic review was to evaluate BNP and NT-proBNP to: (a) identify determinants, (b) establish their diagnostic performance in heart failure (HF) patients, (c) determine their predictive ability with respect to mortality and other cardiac endpoints, and (d) determine their value in monitoring HF treatment.

DATA SOURCES

MEDLINE, EMBASE, CINAHL, Cochrane Central, and AMED from 1989 to February 2005 were searched for primary studies.

REVIEW METHODS

Standard systematic review methodology, including meta-analysis, was employed. All study designs were included. Eligibility criteria included English-only studies and restricted the number of test methods to maximize generalizability. Outcomes for prognosis were limited to mortality and specific cardiac events. Further specific criteria were developed for each research question.

RESULTS

Determinants: There were 103 determinants identified including age, gender, disease, treatment, as well as biochemical and physiological measures. Few studies reported independent associations and of those that did age, female gender and creatinine levels were positively associated with BNP and NT-proBNP.

DIAGNOSIS

Pooled sensitivity and specificity values were 94 and 66 percent for BNP and 92 and 65 percent for NT-proBNP; there was minimal difference among settings (emergency, specialized clinics, and primary care). B-type natriuretic peptides also added independent diagnostic information above traditional measures for HF.

PROGNOSIS

Both BNP and NT-proBNP were found to be independent predictors of mortality and other cardiac composite endpoints in patients with risk of coronary artery disease (CAD) (risk estimate range = 1.10 to 5.40), diagnosed CAD (risk estimate range = 1.50 to 3.00), and diagnosed HF patients (risk estimate range = 2.11 to 9.35). With respect to screening, the AUC values (range = 0.57 to 0.88) suggested poor performance. Monitoring Treatment: Studies showed therapy reduced BNP and NT-proBNP, however, relationship to outcome was limited and not consistent.

CONCLUSIONS

Determinants: The importance of the identified determinants for clinical use is not clear.

DIAGNOSIS

In all settings both BNP and NT-proBNP show good diagnostic properties as a rule out test for HF.

PROGNOSIS

BNP and NT-proBNP are consistent independent predictors of mortality and other cardiac composite endpoints for populations with risk of CAD, diagnosed CAD, and diagnosed HF. There is insufficient evidence to determine the value of B-type natriuretic peptides for screening of HF. Monitoring Treatment: There is insufficient evidence to demonstrate that BNP and NT-proBNP levels show change in response to therapies to manage stable chronic HF patients.