What the Million Hearts Initiative Means for Stroke

Long-term predictors of stroke in healthy middle-aged men

Background

There are few data on risk factors for stroke during long-term follow-up of healthy individuals.

Aims

We aimed to investigate the long-term predictive impact on stroke risk of baseline variables including hemodynamic variables measured at rest and during exercise in middle-aged, healthy men.

Methods

We performed a prospective cohort study of 2014 healthy Norwegian men aged 40–59 years, recruited during the period 1972–1975 and followed until 2007. Participants underwent a comprehensive clinical assessment at baseline, including a bicycle exercise test. Data on stroke, transient ischemic attack, and death were collected on all participants from follow-up visits, medical records, and the National Cause of Death Registry. We used Cox regression for analysis and estimated hazard ratios with 95% confidence intervals, adjusting for traditional risk factors and hemodynamic variables measured at rest and during exercise.

Results

During 35 years’ follow-up, 316 participants (16%) had stroke, of which 287 (91%) were ischemic and 29 (9%) were hemorrhagic. Age (hazard ratio 2.70 per increase in one standard deviation, 95% confidence interval 2.13–3.43), resting systolic blood pressure (hazard ratio 1.24, 95% confidence interval 1.11–1.39), body mass index (hazard ratio 1.14, 95% confidence interval 1.02–1.29), and atrioventricular conduction time (hazard ratio 1.11, 95% confidence interval 1.03–1.19) were significantly associated with long-term risk of stroke, as were maximal systolic blood pressure and heart rate during exercise (hazard ratio 1.28, 95% confidence interval 1.13–1.46, and hazard ratio 0.86, 95% confidence interval 0.74–0.99, respectively).

Conclusions

Hemodynamic variables at rest and during exercise testing add to the predictive value of clinical variables in healthy, middle-aged men, and should be included in the assessment of long-term risk of stroke, when available.

Prevention of stroke: a strategic global imperative

The increasing global stroke burden strongly suggests that currently implemented primary stroke prevention strategies are not sufficiently effective, and new primary prevention strategies with larger effect sizes are needed. Here, we review the latest stroke epidemiology literature, with an emphasis on the recently published Global Burden of Disease 2013 Study estimates; highlight the problems with current primary stroke and cardiovascular disease (CVD) prevention strategies; and outline new developments in primary stroke and CVD prevention. We also suggest key priorities for the future, including comprehensive prevention strategies that target people at all levels of CVD risk; implementation of an integrated approach to promote healthy behaviours and reduce health disparities; capitalizing on information technology to advance prevention approaches and techniques; and incorporation of culturally appropriate education about healthy lifestyles into standard education curricula early in life. Given the already immense and fast-increasing burden of stroke and other major noncommunicable diseases (NCDs), which threatens worldwide sustainability, governments of all countries should develop and implement an emergency action plan addressing the primary prevention of NCDs, possibly including taxation strategies to tackle unhealthy behaviours that increase the risk of stroke and other NCDs.

Preventive Aspirin and Other Antiplatelet Medication Use Among U.S. Adults Aged ≥ 40 Years: Data from the National Health and Nutrition Examination Survey, 2011-2012

OBJECTIVE

We estimated the prevalence of preventive aspirin and/or other antiplatelet medication use and the dosage of aspirin use in the U.S. adult population.

METHODS

We conducted cross-sectional analyses of a representative sample (n=3,599) of U.S. adults aged ≥ 40 years from the National Health and Nutrition Examination Survey, 2011-2012.

RESULTS

In 2011-2012, one-third of U.S. adults aged ≥ 40 years reported taking preventive aspirin and/or other antiplatelet medications, 97% of whom indicated preventive aspirin use. Preventive aspirin use increased with age (from 11% of those aged 40-49 years to 54% of those ≥ 80 years of age, p<0.001). Non-Hispanic white (35%) and black (30%) adults were more likely to take preventive aspirin than non-Hispanic Asian (20%, p<0.001) and Hispanic (22%, p=0.013) adults. Adults with, compared with those without health insurance, and adults with ≥ 2 doctor visits in the past year, diagnosed diabetes, hypertension, or high cholesterol were twice as likely to take preventive aspirin. Among those with cardiovascular disease, 76% reported taking preventive aspirin and/or other antiplatelet medications, of whom 91% were taking preventive aspirin. Among adults without cardiovascular disease, 28% reported taking preventive aspirin. Adherence rates to medically recommended aspirin use were 82% overall, 91% for secondary prevention, and 79% for primary prevention. Among current preventive aspirin users, 70% were taking 81 milligrams (mg) of aspirin daily and 13% were taking 325 mg of aspirin daily.

CONCLUSION

The vast majority of antiplatelet therapy is preventive aspirin use. A health-care provider's recommendation to take preventive aspirin is an important determinant of current preventive aspirin use.

A Genome-wide study of blood pressure in African Americans accounting for gene-smoking interaction

Cigarette smoking has been shown to be a health hazard. In addition to being considered a negative lifestyle behavior, studies have shown that cigarette smoking has been linked to genetic underpinnings of hypertension. Because African Americans have the highest incidence and prevalence of hypertension, we examined the joint effect of genetics and cigarette smoking on health among this understudied population. The sample included African Americans from the genome wide association studies of HyperGEN (N = 1083, discovery sample) and GENOA (N = 1427, replication sample), both part of the FBPP. Results suggested that 2 SNPs located on chromosomes 14 (NEDD8; rs11158609; raw p = 9.80 × 10⁻⁹, genomic control-adjusted p = 2.09 × 10⁻⁷) and 17 (TTYH2; rs8078051; raw p = 6.28 × 10⁻⁸, genomic control-adjusted p = 9.65 × 10⁻⁷) were associated with SBP including the genetic interaction with cigarette smoking. These two SNPs were not associated with SBP in a main genetic effect only model. This study advances knowledge in the area of main and joint effects of genetics and cigarette smoking on hypertension among African Americans and offers a model to the reader for assessing these risks. More research is required to determine how these genes play a role in expression of hypertension.

Comparison of complexity of EMG signals between a normal subject and a patient after stroke--a case study

An innovative method to quantitatively assess the motor function of upper extremities for post-stroke patients is proposed. A post-stroke patient and a normal subject were recruited to conduct a special performance of voluntary elbow flexion and extension by following a sinusoidal trajectory from 30° to 90° at 6 different peak angular velocities in a horizontal plane. During the test, the elbow angle and subject's electromyographic (EMG) signal (biceps brachii and triceps brachii) were recorded simultaneously. Fuzzy approximate entropy (fApEn) was applied to analyze the EMG signals. The results showed observable differences in fApEn when the control and the patient (unaffected and affected arms) were compared, and an uptrend of fApEn was detected with the increase in the tracking velocities in both the normal individual and patient (unaffected and affected arm). The fApEn values, which are a measure of complexity of EMG, could be used for the quantitative evaluation of the deficiencies of motor control induced by stroke.

The effect of covariate adjustment for baseline severity in acute stroke clinical trials with responder analysis outcomes

BACKGROUND

Traditionally in acute stroke clinical trials, the primary clinical outcome employed is a dichotomized modified Rankin Scale (mRS). New statistical methods, such as responder analysis, are being used in stroke studies to address the concern that baseline prognostic variables, such as stroke severity, impact the likelihood of a successful outcome. Responder analysis allows the definition of success to vary according to baseline prognostic variables, producing a more clinically relevant insight into the actual effect of investigational treatments. It is unclear whether or not statistical analyses should adjust for prognostic variables when responder analysis is used, as the outcome already takes these prognostic variables into account. This research aims to investigate the effect of covariate adjustment in the responder analysis framework in order to determine the appropriate analytic method.

METHODS

Using a current stroke clinical trial and its pilot studies to guide simulation parameters, 1,000 clinical trials were simulated at varying sample sizes under several treatment effects to assess power and type I error. Covariate-adjusted and unadjusted logistic regressions were used to estimate the treatment effect under each scenario. In the case of covariate-adjusted logistic regression, the trichotomized National Institute of Health Stroke Scale (NIHSS) was used in adjustment.

RESULTS

Under various treatment effect settings, the operating characteristics of the unadjusted and adjusted analyses do not substantially differ. Power and type I error are preserved for both the unadjusted and adjusted analyses.

CONCLUSIONS

Our results suggest that, under the given treatment effect scenarios, the decision whether or not to adjust for baseline severity when using a responder analysis outcome should be guided by the needs of the study, as type I error rates and power do not appear to vary largely between the methods. These findings are applicable to stroke trials which use the mRS for the primary outcome, but also provide a broader insight into the analysis of binary outcomes that are defined based on baseline prognostic variables.

TRIAL REGISTRATION

This research is part of the Stroke Hyperglycemia Insulin Network Effort (SHINE) trial, Identification Number NCT01369069.

Ideal cardiovascular health predicts lower risks of myocardial infarction, stroke, and vascular death across whites, blacks, and hispanics: the northern Manhattan study

BACKGROUND

Evidence of the relationship of cardiovascular health (CVH), defined by the American Heart Association, and specific cardiovascular outcomes is lacking, particularly among Hispanics. This study sought to evaluate the relationship between the number of ideal CVH metrics and cardiovascular risk, overall and by event subtype, in a multiethnic community-based prospective cohort.

METHODS AND RESULTS

A total of 2981 subjects (mean age, 69±10 years; 54% Caribbean Hispanic, 25% black, 21% white) free of myocardial infarction and stroke at baseline in the Northern Manhattan Study were prospectively followed up (median follow-up, 11 years). The relationship between the number of ideal CVH metrics and the risk of cardiovascular disease, including myocardial infarction, stroke, and vascular death, was investigated. Overall, a strong gradient relationship was observed between the adjusted hazard ratios for cardiovascular disease and the number of ideal CVH metrics: 0.73 (95% confidence interval, 0.60-0.89), 0.61 (95% confidence interval, 0.50-0.76), 0.49 (95% confidence interval, 0.38-0.63), and 0.41 (95% confidence interval, 0.26-0.63) for those having 2, 3, 4, and 5 to 6 ideal CVH metrics, respectively, compared with those having 0 to 1 ideal CVH metrics (P for trend <0.0001). Similar graded relationships were found between the number of ideal CVH metrics and the adjusted incidence rate for each specific outcome and among whites, blacks, and Caribbean Hispanics.

CONCLUSIONS

Our findings demonstrated a steep gradient relationship between ideal CVH and individual cardiovascular disease end points, including stroke, that was similar for whites, blacks, and Caribbean Hispanics. This evidence supports the application of the AHA ideal cardiovascular health metrics for cardiovascular disease risk assessment and health promotion for all Americans regardless of race-ethnic background.