In the Literature: Physician Reviews of HM-Relevant Research
In This Edition
Literature At A Glance
A guide to this month’s studies
- Higher loading dose of clopidogrel in STEMI
- Early vs. late surgery following hip fracture
- Beta-blockers in chronic kidney disease
- Long-term azithromycin in COPD
- CT screening for lung cancer
- Timing of parenteral nutrition in the ICU
- Intrapleural management of empyema with DNase and t-PA
- Effect of weekend elective admissions on hospital flow
- Expectations and outcomes of medical comanagement
Higher-Dose Clopidogrel Improves Outcomes at 30 Days in STEMI Patients
Clinical question: Does a 600-mg loading dose of clopidogrel given before percutaneous coronary intervention (PCI) in patients with an ST-segment elevation myocardial infarction (STEMI) provide more protection from thrombotic complications at 30 days than a 300-mg dose?
Background: Clopidogrel at 600 mg is active more quickly (two hours versus 12 hours) and inhibits platelets more completely than does a 300-mg dose, but it has never been tested prospectively in patients undergoing percutaneous intervention with a STEMI.
Study design: Prospective, multicenter, randomized controlled trial.
Setting: Five hospitals in Italy, Belgium, Serbia, and Hungary.
Synopsis: Two-hundred-one patients with STEMI were randomized to either 600 mg or 300 mg of clopidogrel, given an average of 30 minutes before initial PCI, as well as other standard treatment for STEMI. The primary outcome was “infarct size,” judged as the area under the curve (AUC) of serial creatine kinase-MB (CK-MB) and troponin measurements. At 30 days, patients who received the 600-mg dose of clopidogrel had lower AUCs of cardiac biomarkers, statistically significant (though clinically small) improvement in left ventricle ejection fraction at discharge, lower incidence of severely impaired post-PCI thrombolitis in myocardial infarction (TIMI) flow, and fewer “major cardiovascular events,” driven mainly by a reduction in revascularizations. Measurement of biomarkers to calculate infarct size can be confounded by hypertrophy, and the trial was underpowered for cardiovascular events. However, there was no increase in bleeding events.
Bottom line: In patients with STEMI, treatment with a higher loading dose of clopidogrel before PCI reduces revascularizations and might decrease infarct size without an increase in adverse events.
Citation: Patti G, Bárczi G, Orlic D, et al. Outcome comparison of 600- and 300-mg loading doses of clopidogrel in patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction: results from the ARMYDA-6 MI (Antiplatelet therapy for Reduction of MYocardial Damage during Angioplasty-Myocardial Infarction) randomized study. J Am Coll Cardiol. 2011;58:1592-1599.
Medical Comorbidities Explain Most of Excess Risk Seen in Patients with Delayed Hip Fracture Repair
Clinical question: Could the increased mortality found with delays in hip fracture surgery be confounded by the premorbid functional status and medical comorbidities of patients whose surgery is more likely to be delayed?
Background: Guidelines recommend operating on patients with hip fracture within 24 hours, but the supporting evidence has not adjusted for underlying medical comorbidities, which could delay surgery and contribute to poor outcomes, making delays look harmful.
Study design: Prospective cohort, single-center design.
Setting: University hospital in Spain.
Synopsis: The study included 2,250 consecutive elderly patients admitted to the hospital for hip fracture who had their functional status and medical comorbidities assessed at enrollment. If their surgery was delayed beyond 24 hours, the reason was sought. Medical outcomes assessed daily while in hospital were delirium, pneumonia, heart failure, urinary tract infection, and new pressure sores, while the dose of pain medication, surgical complications, and in-hospital mortality were also compiled. No post-discharge data were available.
