05 OCT 2012
CHICAGO – Among patients with either coronary artery disease (CAD) risk factors only, known prior heart attack, or known CAD without heart attack, the use of beta-blockers was not associated with a lower risk of a composite of cardiovascular events that included cardiovascular death, nonfatal heart attack or nonfatal stroke, according to a study in the October 3 issue of JAMA.
“Treatment with beta-blockers remains the standard of care for patients with coronary artery disease, especially when they have had a myocardial infarction [MI; heart attack]. The evidence is derived from relatively old post-MI studies, most of which antedate modern reperfusion or medical therapy, and from heart failure trials, but has been widely extrapolated to patients with CAD and even to patients at high risk for but without established CAD. It is not known if these extrapolations are justified. Moreover, the long-term efficacy of these agents in patients treated with contemporary medical therapies is not known, even in patients with prior MI,” according to background information in the article.
Sripal Bangalore, M.D., M.H.A., of the NYU School of Medicine, New York, and colleagues conducted a study to evaluate the association between beta-blocker use and long-term cardiovascular outcomes. The observational study included data from patients in the Reduction of Atherothrombosis for Continued Health (REACH) registry. From this registry, 44,708 patients met the study inclusion criteria of whom 14,043 patients (31 percent) had prior MI, 12,012 patients (27 percent) had documented CAD but without MI, and 18,653 patients (42 percent) had CAD risk factors only. The last follow-up data collection was April 2009. The primary outcome for this study was a composite of cardiovascular death, nonfatal MI, or nonfatal stroke. The secondary outcome was the primary outcome plus hospitalization for atherothrombotic events or a revascularization procedure. The overall median (midpoint) follow-up was 44 months. Among the 44,708 patients in the study, 21,860 were included in the propensity score-matched analysis.
The researchers found that in the prior MI group, the event rates were not significantly different among those with beta-blocker use (489 [16.93 percent]) vs. those without beta-blocker use (532 [18.60 percent]) for the primary outcome, or the secondary outcome (30.96 percent vs. 33.12 percent, respectively). In the CAD without MI cohort, the event rates were not different in those with beta-blocker use (391 [12.94 percent]) vs. those without p-blocker use (405 [13.55 percent]) for the primary outcome, for cardiovascular death, for stroke, and for MI. The event rates were higher in those with beta-blocker use (1,101 [30.59 percent] vs. those without beta-blocker use (1,002 [27.84 percent]) for the secondary outcome and for hospitalization in the propensity score-matched model.
In the risk factors alone group, the event rates were higher in those with beta-blocker use (467 [14.22 percent] vs. those without beta-blocker use (403 [12.11 percent]) for the primary outcome, for the secondary outcome (870 [22.01 percent] vs. 797 [20.17 percent], respectively) but not for MI or stroke. In the propensity score-matched model, there were similar event rates for cardiovascular death and for hospitalization.
The researchers also found that among patients with recent MI (one year or less), beta-blocker use was associated with a lower incidence of the secondary outcome.
“Among patients enrolled in the international REACH registry, beta-blocker use was not associated with a lower event rate of cardiovascular events at 44-month follow-up, even among patients with prior history of MI. Further research is warranted to identify subgroups that benefit from beta-blocker therapy and the optimal duration of beta-blocker therapy,” the authors conclude.
Low levels of vitamin D are associated with mortality in older adults
New study shows vitamin D insufficiency more common in African Americans than Caucasians
Chevy Chase, MD—Low levels of vitamin D and high levels of parathyroid hormone are associated with increased mortality in African American and Caucasian older adults, according to a new study accepted for publication in The Endocrine Society’s Journal of Clinical Endocrinology and Metabolism (JCEM). The study also indicates that the potential impact of remediating low vitamin D levels is greater in African Americans than Caucasians because vitamin D insufficiency is more common in African Americans.
For the past several years, there has been considerable interest in the role vitamin D plays in improving health and preventing disease. Low levels of vitamin D have been directly associated with various forms of cancer and cardiovascular disease. Most studies regarding the health effects of low vitamin D levels have been conducted on persons of European origin, but the current study examines the relationship between vitamin D and mortality in blacks and whites.
“We observed vitamin D insufficiency (defined as blood levels <20 ng/ml), in one third of our study participants. This was associated with nearly a 50 percent increase in the mortality rate in older adults,” said Stephen B. Kritchevsky, PhD, Professor of Internal Medicine and Transitional Science at the Wake Forest School of Medicine, and lead researcher of this study. “Our findings suggest that low levels of vitamin D may be a substantial public health concern for our nation’s older adults.”
In this study, 2,638 Caucasians and African-Americans aged 70-79 years were asked to fast for 12-hours, after which a blood sample was collected to determine levels of vitamin D. Every six months study participants were contacted to ascertain their medical condition. This study determined the proportion of deaths among participants of with different vitamin D levels. In addition to many health factors, the time of year was also taken into account due to the seasonal effects on vitamin D. Researchers found that levels of vitamin D less than 30 ng/ml were associated with significantly increased all-cause mortality.
“We all know that good nutrition is important to overall health and our study adds to a growing body of literature that underscores the importance of vitamin D and indicates that poor vitamin D nutrition is wide-spread,” said Kritchevsky. “The good news is it’s easy to improve vitamin D status either through increased skin exposure to sunlight or through diet or supplements.”
Categories: Ineffective Treatments