CHEST Guidelines-Age-Adjusted-D-dimer-Cutoff-for-Reducing-CT-Pulmon

Age-Adjusted-D-dimer-Cutoff-for-Reducing-CT-Pulmon

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The document discusses the use of an age-adjusted D-dimer cutoff for diagnosing pulmonary embolism (PE) in elderly patients, aiming to reduce unnecessary CT pulmonary angiography (CTPA) tests. Traditionally, D-dimer tests in elderly patients often result in false positives, leading to excessive CTPA procedures where only 10-15% confirm PE. An age-adjusted D-dimer cutoff (age x 10 for those over 50) is proposed to mitigate this issue. <br /><br />Woller et al. expanded on this approach by studying a cohort of 934 patients over 50 with suspected PE, finding that 29% had D-dimer levels below the age-adjusted cutoff. With follow-up, only 1.5% were later diagnosed with PE, indicating a failure rate within acceptable limits when compared to traditional methods, which required CTPA for only 11% who had negative conventional D-dimer results.<br /><br />The age-adjusted approach led to nearly a 20% reduction in required CTPAs compared to the traditional method. The document discusses whether a slightly higher failure rate is acceptable given the reduction in CTPA tests and associated risks like radiation and contrast nephropathy.<br /><br />The necessity for a formal randomized controlled trial (RCT) to compare age-adjusted and conventional D-dimer cutoffs is emphasized, although logistical and financial constraints make such trials challenging. Instead, indirect analysis via individual patient data meta-analysis is suggested to explore the implications further, particularly in various elderly subpopulations.<br /><br />Overall, the use of an age-adjusted D-dimer cutoff is portrayed as a promising strategy to reduce unnecessary CTPA tests in the elderly while maintaining patient safety, though further research is warranted to confirm these findings comprehensively.

Keywords

age-adjusted D-dimer

pulmonary embolism

CT pulmonary angiography

elderly patients

false positives

Woller et al.

failure rate

randomized controlled trial

meta-analysis

patient safety