Is CT pulmonary angiography overutilized in the evaluation of patients with suspected pulmonary embolism? A retrospective study

Introduction Despite the high mortality rate of acute untreated pulmonary embolism (PE) at 30%, diagnosing PE is challenging. While the prevalence of PE has decreased in recent years, the overuse of computed tomography pulmonary angiography (CTPA) remains a concern. The National Institute for Health and Care Excellence (NICE) provides guidelines using the Wells score for PE assessment. The Royal College of Radiologists (RCR) recommends a positive yield of 15.4% - 37% for CTPA tests. This study assesses the positive yield of CTPA for suspected PE patients and evaluates the potential reduction through Wells score/D-dimer assessment as recommended by NICE. Methods All patients who underwent CTPA between September 1, 2019, and January 31, 2020, at Salmaniya Medical Complex were included. Data on patient demographics and pre-CTPA workup were collected from electronic patient records (EPR) and stored in MS Excel 2019 for analysis. Results Of 188 suspected PE patients (mean age 50 ±12.3 years; 62.8% female), 12.2% were diagnosed with PE. None had documented Wells scores. A low-risk Wells score (≤4) was assigned to 68.6% of patients, with only 26.1% undergoing D-dimer testing. PE was confirmed in 4 patients with low-risk Wells scores and elevated D-dimers. All 10 patients with low-risk Wells scores and negative D-dimers were PE-negative. Conclusion In total, 5.3% - 47.9% of the CTPAs conducted could have been avoided by following NICE guidelines. We propose integrating an algorithm-based checklist with validated tools like the Wells and Geneva scores into the ePMA system to guide appropriate CTPA referrals, promote evidence-based decision-making, reduce unnecessary imaging, and optimize patient care and resource use.