Hemodynamic shear stress decreases in regions of low flow velocity,
shown in blue on this flow velocity map of the carotid bifurcation at end-systole.
Reduced shear stress stimulates endothelial function that predisposes to atherogenesis.
Treatment of acute ischemic stroke has been limited by the need to intervene
within 3 hours of symptom onset. In a trial of intra-arterial recombinant
prourokinase (r-proUK) administered with low-dose heparin within 6 hours of
stroke onset to patients with acute ischemic stroke and angiographically proven
occlusion of the middle cerebral artery, Furlan and colleagues found that
significantly more patients who received r-proUK had good neurologic recovery
at 90 days than patients who received heparin alone. Early intracranial hemorrhage
was increased in the r-proUK group compared with the control group, but rates
of intracranial hemorrhage at day 10 and 90-day mortality were similar. In
a placebo-controlled trial of intravenous recombinant tissue-type plasminogen
activator (rt-PA) administered between 3 and 5 hours after symptom onset,
Clark and colleagues found no significant difference in neurologic recovery
90 days after treatment. The rate of symptomatic intracerebral hemorrhage
within the first 10 days of treatment, however, was significantly higher in
the rt-PA group.
See Article and Article
In this analysis of data from a subcohort of 366,559 individuals aged
18 to 59 years with a low risk-factor profile for cardiovascular disease (serum
cholesterol level less than 5.17 mmol/L [<200 mg/dL], blood pressure less
than or equal to 120/80 mm Hg, and no current cigarette smoking) who had been
enrolled in 2 long-term prospective studies, Stamler and colleagues found
that the risk of coronary heart disease mortality was 0.08 to 0.23 and of
cardiovascular death, 0.15 to 0.28, in the low-risk group compared with all
others. The estimated greater life expectancy associated with a favorable
risk profile ranged from 5.8 years to 9.5 years.
Individuals who are overweight may be more sensitive to adverse effects
of dietary sodium on cardiovascular health than normal weight individuals.
In an analysis of data from the first National Health and Nutrition Examination
Survey Epidemiologic Follow-up Study (mean follow-up, 19 years), He and colleagues
report that among overweight persons, a 100-mmol increase in dietary sodium
intake was associated with a significantly increased risk of stroke and of
cardiovascular and all-cause mortality. No significant association was found
between dietary sodium intake and cardiovascular disease risk among individuals
who were not overweight.
Based on a review of data from 37 clinical trials on the effects of
cholesterol lowering on coronary events and mortality, stroke, and total mortality
published since 1993, Ansell and colleagues assessed the recommendations of
the Second Report of the National Cholesterol Education Program (NCEP) Expert
Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in
Adults (Adult Treatment Panel II). The authors conclude that despite some
important differences, the selected lipid intervention trials generally support
the NCEP guidelines and present an evidence-based algorithm for lipid-lowering
In this meta-analysis of data from more than 20,000 patients with coronary
artery disease (CAD) enrolled in 31 trials of oral anticoagulant (OA) therapy,
Anand and colleagues found that compared with control, high-intensity (international
normalized ratio [INR], 2.8-4.8) OA therapy reduced risk of mortality by 22%,
myocardial infarction by 42%, and thromboembolic events by 63%, and moderate-intensity
(INR, 2-3) OA therapy reduced risk of mortality by 18%, myocardial infarction
by 52%, and stroke by 53%, but risk of major bleeding increased 6.0- to 7.7-fold.
Moderate- to high-intensity (INR ≥2) OA therapy did not improve outcomes
compared with aspirin and was associated with a 2.4-fold increased risk of
Steinberg and Gotto review the research that validated the relationship
between lipid disorders and coronary artery disease (CAD) since the founding
of the National Heart Institute in 1948.
Lenfant reflects on changes in cardiovascular health, recent progress
in cardiovascular disease research, and questions still unanswered.
Several lines of evidence suggest an association between Chlamydia pneumoniae and atherosclerosis.
For your patients: How to stay healthy.
This Week in JAMA. JAMA. 1999;282(21):1987. doi:10.1001/jama.282.21.1987