Author + information
- Kelly M. Chin, MD⁎ ( and )
- Lewis J. Rubin, MD
- ↵⁎University of Texas Southwestern Medical Center, Department of Internal Medicine, Division of Pulmonary and Critical Care, Dallas, Texas 75235
We thank Dr. Kapoor for his thoughtful letter regarding our article (1). Bloodstream infections are an important complication of indwelling catheters and, in this Centers for Disease Control and Prevention (CDC) report, the overall infection rate with treprostinil was significantly greater than that of epoprostenol (incidence rate ratio 2.57, 95% confidence interval: 1.81 to 3.64). The rate of gram-negative infections was also much greater with treprostinil, with gram-negative infections actually more common than gram-positive infections. This finding suggests that, when line infection is suspected in patients receiving intravenous treprostinil, the empiric use of antibiotics with both gram-positive and -negative coverage should be considered until blood culture results are available.
However, these findings do not rise to the level of robust scientific proof: First, just before the initiation of the study, an alert letter from United Therapeutics (Silver Spring, Maryland), the manufacturer of treprostinil, was distributed requesting that physicians report any gram-negative bacteremia cases for further evaluation. Shortly after this concern was raised, the CDC asked centers where treprostinil was used frequently to participate in a more formal study. It is possible that centers with increased rates of gram-negative infections were more likely to participate, particularly given the increased awareness prompted by the alert letter. Second, there appeared to be significant heterogeneity within the results, with incidence rate ratios for infections with treprostinil compared with epoprostenol ranging from 0.59 to 3.90 across the 5 centers from which data were available for both medications. Finally, data were collected retrospectively and over different years at each site, the CDC was not directly involved in the data collection at most sites, and the information was only presented as a 2-page brief rather than a full, peer-reviewed research paper. Thus, although the CDC report raises awareness to the risk and provides guidance for the current treatment of suspected line infections, additional formal study is required.
- American College of Cardiology Foundation