The impact of using different age-adjusted cutoffs of D-dimer in the diagnosis of pulmonary thromboembolism

Background This study was conducted to evaluate the relationship of age-adjusted D-dimer value with different coefficients in diagnosis of pulmonary embolism (PE) in geriatric patients. Methods The emergency admissions of the patients aged 65 and over with suspected PE during 2018 were reviewed retrospectively. The demographic characteristics, laboratory tests and radiologic findings of computed tomography pulmonary angiogram (CTPA) or single photon emission computed tomography ventilation/perfusion scintigraphy (V/Q) were recorded. The characteristics of the patients with PE were statistically compared with the patients without PE. The specificity and sensitivity for higher cut-off levels (age × 10-15) were presented. Results PE was detected in 39.2% (n = 246) of 628 patients aged 65 years and older included in the study. The multivariate analysis revealed that higher D-dimer level (OR = 1,00011; p 0.001) and BUN level (OR = 1.025; p = 0.013) were independent risk factors for PE diagnosis in elderly patients. Diagnostic statistics for D-dimer cut-off levels selected from ROC analysis and calculated values as 10-15 times of age showed that if the D-dimer cut-off value used is chosen higher, lower sensitivity rates are obtained. Our results also indicated that the patients with malignancy, renal failure, central PE on CTPA and PE with high probability on SPECT VQ were presented with higher D-dimer values. Conclusion Our results do not support the use of higher D-dimer cut-off levels such as 15 times the age in geriatric population. The impact of the location of PE and comorbidities on the outcomes of these patients must be clarified for determining cut-offs with higher specificity.