Major cardiac events occurred more often in patients with acute versus chronic beta-blocker exposure in both the entire cohort (8.3% vs. 4.7%) and in the propensity-matched cohort (8.0% vs. 3.0%). Myocardial infarction accounted for the majority of cardiac events.
There are several limitations of this study: The sample size was small, the beta-blocker and dosage used varied, and the indication and exact duration of chronic beta-blocker therapy was unknown.
Bottom line: Chronic beta-blocker therapy reduces major cardiac events compared with acute beta-blocker therapy in patients undergoing elective, noncardiac surgery.
Citation: Ellenberger C, Tait G, Beattie WS. Chronic beta-blockade is associated with a better outcome after elective noncardiac surgery than acute beta-blockade: a single-center propensity-matched cohort study. Anesthesiology. 2011;114(4):817-823.
Continuous and Bolus Dosing of Furosemide Provides Similar Outcomes in Heart Failure
Clinical question: Does continuous infusion compared to bolus dosing of furosemide improve clinical outcomes in patients with acute decompensated heart failure?
Background: Diuresis with furosemide is commonly used to manage acute decompensated heart failure, but it is uncertain which dosing strategy is optimal. Continuous infusion of furosemide has been proposed as a more effective method of diuresis compared with bolus dosing, especially when higher doses are required, but data comparing the two strategies are limited.
Study design: Randomized, double-blind, controlled trial.
Setting: Twenty-six clinical sites in the U.S. and Canada.
Synopsis: Researchers randomized 308 patients with acute decompensated heart failure to either continuous or bolus intravenous dosing, which was calculated as either the equivalent of their daily oral dose (low-dose strategy) or 2.5 times their daily dose (high-dose strategy). Mean ejection fraction was 35%. Primary endpoints were patients’ assessment of symptoms based on a visual-analogue scale quantified as area under the curve, as well as change in serum creatinine level at 72 hours.
No significant differences between the continuous and bolus dosing groups were evidenced in primary endpoints at 72 hours. Patients in the bolus group had more dose increases at 48 hours (21% vs. 11%, P=0.01). Patients in the high-dose group were more likely to change from intravenous to oral doses at 48 hours (31% vs. 17%, P<0.001) and had greater net fluid loss (4.9L vs. 3.6L, P=0.01). More patients in the high-dose versus low-dose group had an increase in creatinine ≥0.3 mg/dL (23% vs. 14%, P=0.04). Hospital length of stay, readmission, and mortality rates were similar between the groups.
Bottom line: Diuretic therapy administered by continuous infusion or bolus dosing in patients with acute decompensated heart failure have equivocal effects on patients’ symptoms and kidney function.
Citation: Felker GM, Lee KL, Bull DA, et al. Diuretic strategies in patients with acute decompensated heart failure. N Engl J Med. 2011;364(9):797-805.
Carotid Endarterectomy Is Better than Carotid Artery Stenting
Clinical question: How do the clinical outcomes of carotid artery stenting compare with those of carotid endarterectomy?
Background: Whether carotid artery stenting or carotid endarterectomy is the preferred therapy for patients with carotid artery stenosis has been highly controversial. This study was a meta-analysis of all available data from randomized trials comparing carotid endarterectomy to carotid artery stenting.
Study design: Meta-analysis.
Setting: Teaching and nonteaching hospitals.