Clinical Research in Primary Stroke Prevention: Needs, Opportunities, and Challenges

Antihypertensives and Statin Therapy for Primary Stroke Prevention: A Secondary Analysis of the HOPE-3 Trial

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What’s new in stroke prevention and treatment

This review summarizes the latest results and developments in stroke prevention and acute treatment studies published in 2004 and 2005. In contrast to primary prevention in men, aspirin did not significantly reduce the risk of myocardial infarction or death from cardiovascular causes in women over 45 years of age. Patients with symptomatic intracranial stenosis do not benefit from secondary prevention with oral anticoagulation. Magnetic resonance-based acute stroke studies with recombinant tissue plasminogen activator (rtPA) or with desmoteplase, a new thrombolytic agent, showed similar safety and potential benefit beyond the 3-h time window, as with the established inclusion criteria of rtPA. The surgical trial in intracerebral hemorrhage (STICH) failed to demonstrate any benefit for early operative evacuation of hematoma. The authors aim to provide a wide overview of stroke prevention and acute treatment studies published in 2004 and 2005. Relevant journals were hand-searched to compile a broad, but not comprehensive, summary of innovative and clinically relevant findings. A short critical evaluation at the end of selected reviews should encourage the reader to further reading of studies of interest.

Clinical correlates of cerebral white matter hyperintensities in cognitively normal older adults

Many research studies have demonstrated asymptomatic white matter hyperintensities (WMHs) in older adults, which are postulated to be ischemic in origin. We hypothesized that certain clinical predictors, measured in a population of healthy older adults, would have a positive relationship with WMH scoring on magnetic resonance imaging (MRI). As part of a longitudinal study of cognitive aging we have performed MRI on healthy older adults. In a group of 46 volunteers (25 females; median age 73, range 63-84 years), we have calculated of the Hachinski score and Framingham Stroke Risk Profile (FSRP). Volunteers also provided self-reported health information using the Cornell Medical Index (CMI). These were compared against the total Age Related White Matter Changes (ARWMC) score. The mean total ARWMC score was 7.4 + or - 5.27 (+ or - S.D.) and only 3 (6.5%) individuals had no evidence of WMH. Regression analysis of individual variables identified self-report of cardiovascular disease from the CMI, section C as the only significant predictor of ARWMC. A multivariate linear regression model also identified FSRP at 1 year as a second independently significant predictor. The multivariate model accounted for 19% of the variance in total ARWMC score. The only 6.5% of individuals who had no WMH is in keeping with previous studies. The important finding was the positive relationship with self-reported cardiovascular disease, which is a possible biomarker of sub-clinical cerebrovascular disease (CVD).

Challenges of designing trials for the primary prevention of stroke

BACKGROUND AND PURPOSE

Prevention of a first stroke is an important strategy to reduce morbidity and mortality associated with cerebrovascular disease. In this discussion, we review challenges to development of clinical trials for prevention of a first stroke. Summary of Review- We discuss prevention of first stroke in the context of clinical trial design in the ARRIVE trial and a primary prevention trial in development for the elderly.

CONCLUSIONS

Stroke is an important outcome in cerebrovascular disease trials in the elderly, but it may be trumped by coronary heart disease as a more common end point.

The 2006 William Feinberg lecture: shifting the paradigm from stroke to global vascular risk estimation

By the year 2010, it is estimated that 18.1 million people worldwide will die annually because of cardiovascular diseases and stroke. "Global vascular risk" more broadly includes the multiple overlapping disease silos of stroke, myocardial infarction, peripheral arterial disease, and vascular death. Estimation of global vascular risk requires consideration of a variety of variables including demographics, environmental behaviors, and risk factors. Data from multiple studies suggest continuous linear relationships between the physiological vascular risk modulators of blood pressure, lipids, and blood glucose rather than treating these conditions as categorical risk factors. Constellations of risk factors may be more relevant than individual categorical components. Exciting work with novel risk factors may also have predictive value in estimates of global vascular risk. Advances in imaging have led to the measurement of subclinical conditions such as carotid intima-media thickness and subclinical brain conditions such as white matter hyperintensities and silent infarcts. These subclinical measurements may be intermediate stages in the transition from asymptomatic to symptomatic vascular events, appear to be associated with the fundamental vascular risk factors, and represent opportunities to more precisely quantitate disease progression. The expansion of studies in molecular epidemiology and detection of genetic markers underlying vascular risks also promises to extend our precision of global vascular risk estimation. Global vascular risk estimation will require quantitative methods that bundle these multi-dimensional data into more precise estimates of future risk. The power of genetic information coupled with data on demographics, risk-inducing behaviors, vascular risk modulators, biomarkers, and measures of subclinical conditions should provide the most realistic approximation of an individual's future global vascular risk. The ultimate public health benefit, however, will depend on not only identification of global vascular risk but also the realization that we can modify this risk and prove the prediction models wrong.