To the Editor.
—The analysis of the effectiveness of the RHC by Dr Connors and colleagues1 raises important questions. The crux of the problem is that RHC is a monitoring device, not a treatment, and the increased risk of death in the RHC group was associated with an increase in intervention. The information the authors provide does not allow RHC effects and treatment effects to be separated. It is possible that the presence of an RHC is harmful and results in a worse outcome, but it is generally accepted that insertion is safe when performed by an experienced physician and that the complication rate is low.2 Moreover, the relative hazard of death was only 1.02 (95% confidence interval, 0.55-1.89; P=.94) in the patients with congestive cardiac failure, who might be considered most at risk from a direct complication of the RHC. Another possibility, referred to by the authors, is
Beale RJ, Wyncoll D, McLuckie A. Effectiveness of Right Heart Catheterization: Time for a Randomized Trial. JAMA. 1997;277(2):110. doi:10.1001/jama.1997.03540260024017