Or, if it does, this is not the article that shows it. It tries to show it – and Rick Bukata, who I love, includes it as part of his PE review in this month’s Emergency Physician’s Monthly. It’s a year and a half old, but I had to pull it because I’ve presented other articles showing the diagnosis and treatment of pulmonary embolism isn’t changing mortality.
This is from the Mayo clinic, and it’s observational, retrospective cohort data, which is red flag #1 for drawing practice-changing conclusions. They reviewed charts on 400 symptomatic pulmonary embolism identified on CTPA that were subsequently admitted to the hospital and anticoagulated with systemic heparin. In their introduction, they set out to show that outcomes are improved in pulmonary embolism if you initiate heparin in the Emergency Department. In the end, their conclusion is essentially summarized by this graphic:
Seems pretty convincing, eh?
And, it’s true, there was a significant association between heparin in the ED and 30-day survival. There was also, however, a significant association between 30-day survival and: tachycardia, Wells score, leukocytosis, elevated troponin, malignancy, recent surgery, ICU admission, and hemorrhagic events. So, did patients die because they didn’t get heparin, or did they die because they were more acutely ill – and/or had a hemorrhagic event after initiating heparin? The big one for me is the difference between positive (>0.01 ng/mL) troponins – 26.4% in their survivors and 47.8% in the non-survivors. Considering the criteria for diagnosis of submassive pulmonary embolism – patients who occupy a different level of risk for poor outcomes – includes elevated troponins indicative of right heart strain, I think this study doesn’t properly support anything it tries to imply regarding the time to heparin and survival.
“Early Anticoagulation Is Associated With Reduced Mortality for Acute Pulmonary Embolism”
www.ncbi.nlm.nih.gov/pubmed/20081101