Pulmonary Embolism: Incidence, spectrum of CTPA findings, and correlation of D-dimers with embolus location. Is age-adjusted D-dimers cutoff a better screening method?

Introduction: Diagnostic work-up of pulmonary embolism (PE) remains a challenge. Aim/Methods: To investigate PE incidence in all clinically suspected patients who underwent computed tomographic pulmonary angiography (CTPA) during a 12-month period (2018) and to access the diagnostic performance of conventional and age-adjusted D-Dimers (Dd) cutoff. A new Dd cutoff reducing the need for CTPA was documented. The spectrum of CTPA findings and correlation of plasma Dd with PE location and CTPE findings were recorded. Results: We analyzed 1017 patients (53,98% males, mean age: 64,1 ± 16 years). Overall incidence of PE was 18,68%. Central and bilateral embolism was present in 44,7% and 59,5%, respectively. Sensitivity, specificity and NPV for conventional and age-adjusted Dd cutoff was 98,2%, 7,9%, 95,2%, and 98,2%, 13,1%, 97%, respectively. ROC analysis identified a new Dd cutoff (0,74) with 97% sensitivity, 20,52% specificity, and 97 NPV (AUC= 0,72, 95% CI 0,67 to 0,77) reducing the need for CTPA by 17,2%. Consolidation/atelectasis and unilateral pleural effusion were significantly associated with PE (p<0,05 for both). Strong correlation of plasma Dd with central and unilateral PE, as well as in cases with consolidation/atelectasis and intrapulmonary nodule(s)/mass on CTPA (p<0,001 for both). Conclusion: Implementation of age-adjusted Dd cutoff tends to achieve better screening of patients who should undergo CTPA. The suggested Dd cutoff value increases specificity without increasing false-negative results, reducing the need for CTPA.