Objective: To estimate the frequency of contrast nephropathy after computed tomography angiography (CTA) to rule out pulmonary embolism (PE) in the emergency department (ED) setting.
Methods: We prospectively followed patients undergoing CTA for PE, while in the ED, for 45 days. Patients who refused follow-up or were receiving hemodialysis were excluded. Severe renal failure was defined as an increase in creatinine > or = 3.0 mg dL(-1) or a need for hemodialysis within the follow-up period. Patients were also followed for laboratory-defined contrast nephropathy, defined as an increase in creatinine of > 0.5 mg dL(-1) or > 25%, within seven days following CTA.
Results: A total of 1224 patients were followed, and 354 [29%, 95% confidence interval (CI): 26-32%] patients had paired (preCTA and post-CTA) creatinine measurements. None developed renal failure (0/1224; 0%, CI: 0-0.3%). 44 patients developed laboratory-defined contrast nephropathy, corresponding to an overall frequency of 4% (44/1224; CI: 3-5%) and 12% (44/354; 95% CI: 9-16%) among those with paired creatinine measurements.
Conclusions: Following CTA for PE, the incidence of severe renal failure was very low, but the incidence of laboratory-defined contrast nephropathy (4% overall and 12% of those with paired measurements) was higher than expected.