In the Literature: HM-Related Research You Need to Know

Bottom line: There is no definitive reduction in mortality with prophylactic ICD therapy in elderly patients with severe left ventricular dysfunction.

Citation: Santangeli P, Di Biase L, Dello Russo A, et al. Meta-analysis: age and effectiveness of prophylactic implantable cardioverter-defibrillators. Ann Intern Med. 2010;153(9):592-599.

System Delay Is Mortality Marker in STEMI Patients Treated with Primary PCI

Clinical question: What is the relationship between system delays to reperfusion therapy and mortality in patients with ST-segment-elevation myocardial infarction (STEMI)?

Background: In patients with STEMI, an early reperfusion strategy is often sought, and several studies have focused on the association between door-to-balloon delay and outcomes. Focusing more broadly on the time from first contact with the healthcare system to the initiation of reperfusion therapy (system delay) might be a more relevant approach.

Study design: Historical follow-up study.

Setting: Three high-volume PCI centers in Denmark.

Synopsis: Using population-based medical registries of 6,209 Danish patients treated for STEMI with percutaneous coronary intervention (PCI), the authors examined the association between delays in reperfusion therapy and mortality. System delay encompassed the entire time from first contact with the healthcare system to the initiation of reperfusion therapy.

Overall, shorter system delay was associated with significantly decreased mortality, as were the individual components of system delay (prehospital delay and door-to-balloon delay). The shortest delays (0-60 minutes) corresponded to a mortality rate of 15%, and the longest delays (181-360 minutes) corresponded to a mortality rate of 31%. Patients were followed for a median of 3.4 years.

This study is unique, as it is the first to look at the association between system delay and outcomes in patients with STEMI transported by EMS and treated with primary PCI. The study highlights the harmful impact of longer system delays on mortality. Limitations of this study include possible underestimation of system delay and challenges surrounding the right marker for reperfusion.

Bottom line: System delay might serve as a broad, comprehensive marker for predicting mortality in patients with STEMI treated with primary PCI.

Citation: Terkelsen CJ, Sorensen JT, Maeng M, et al. System delay and mortality among patients with STEMI treated with primary percutaneous coronary intervention. JAMA. 2010;304(7): 763-771.

Clinical Shorts

ANTIMICROBIAL TREATMENT FOR SUSPECTED PNEUMONIA IN ADVANCED DEMENTIA PROLONGS SURVIVAL WITHOUT IMPROVING COMFORT

Prospective data from 323 nursing home residents with advanced dementia and suspected pneumonia found that patients treated with antimicrobial agents versus no treatment had improved survival but did not have improved comfort scores.

Citation: Givens JL, Jones RN, Shaffer ML, Kiely DK, Mitchell SL. Survival and comfort after treatment of pneumonia in advanced dementia. Arch Intern Med. 2010;170(13):1102-1107.

FOLIC ACID AND VITAMIN B12 SUPPLEMENTATION DO NOT HAVE BENEFICIAL EFFECTS ON VASCULAR OUTCOMES OR ADVERSE EFFECTS ON CANCER INCIDENCE

Double-blind randomized controlled trial of 12,064 patients with history of myocardial infarction given 2 mg folic acid and 1 mg vitamin B12 daily vs. placebo found reductions in homocysteine levels, but no significant reduction in coronary events, death, or cancer incidence.

Citation: Armitage JM, Bowman L, Clarke RJ, et al. Effects of homocysteine-lowering with folic acid plus vitamin B12 vs placebo on mortality and major morbidity in myocardial infarction survivors: a randomized trial. JAMA. 2010;303(24):2486-2494.

D-Dimer Is Effective in Determining the Risk of VTE Recurrence after First Unprovoked Event

Clinical question: Does the timing, patient age, or cut point level affect the predictive value of a D-dimer in predicting VTE recurrence after a first unprovoked event?

Background: Anticoagulation duration after a first unprovoked VTE is at least three months, but it can be indefinite in patients with stable anticoagulation and low bleeding risk. Measuring a D-dimer level after discontinuation of anticoagulation is helpful in determining which patients might benefit from prolonged anticoagulation. However, several unanswered questions remain regarding D-dimer testing.