Letters Section Editor: Robert M. Golub, MD, Senior Editor.
In Reply: Dr Mir questions whether we could have excluded pulmonary embolism on the basis of a negative CTPA or / scan combined with 1 or 2 negative ultrasound evaluations for deep vein thrombosis without the performance of an additional pulmonary imaging procedure. Although the use of conventional or digital subtraction pulmonary angiogram may have enhanced the diagnostic yield of pulmonary embolism, the safety of our strategies was demonstrated: only 2 of 561 patients (0.4%) randomized to CTPA and 6 of 611 patients (1.0%) undergoing / scanning who were classified as having pulmonary embolism excluded developed venous thromboembolism in follow-up. These rates compare very favorably with the 1.6% rate of venous thromboembolism that was demonstrated in 1-year follow-up of a cohort of patients who had the diagnosis of pulmonary embolism excluded by pulmonary angiography.1
Anderson DR, Rodger MA, Wells PS. Excluding Pulmonary Embolism With Computed Tomographic Pulmonary Angiography or Ventilation-Perfusion Lung Scanning—Reply. JAMA. 2008;299(14):1664-1665. doi:10.1001/jama.299.14.1664-c