YEARS BEFORE COMPUTED TOMOGRAPHY PULMONARY ANGIOGRAPHY: DIAGNOSTIC UTILITY AND POTENTIAL IMAGING REDUCTION IN SUSPECTED PULMONARY EMBOLISM

Abstract

Background: Acute pulmonary embolism (PE) is a cardiovascular emergency, yet securing a swift diagnosis is notoriously difficult due to its highly non-specific presentation. Computed Tomography Pulmonary Angiography (CTPA) serves as the diagnostic gold standard, but its routine overuse exposes patients to unnecessary radiation, increases the risk of contrast-induced nephrotoxicity, and heavily strains healthcare resources. The YEARS algorithm offers a streamlined alternative, relying on three core clinical features and variable D-dimer thresholds to safely rule out PE without advanced imaging. Methods: This prospective observational diagnostic accuracy study evaluated 80 haemodynamically stable adults presenting with suspected acute PE in a tertiary care setting. We assessed the three YEARS items (clinical signs of deep vein thrombosis, haemoptysis, and PE as the most likely diagnosis) prior to any imaging. Patients with zero positive items utilized a D-dimer exclusion threshold of <1000 ng/mL FEU, while those with one or more items used a stricter <500 ng/mL FEU cutoff. Every participant subsequently underwent CTPA as the definitive reference standard. Results: CTPA confirmed acute PE in 14 of the 80 patients (a 17.50% prevalence). The YEARS algorithm achieved a strong sensitivity of 92.86% and a specificity of 48.48%, alongside an excellent negative predictive value of 96.97%. Implementing the YEARS protocol would have safely bypassed CTPA in 33 patients, achieving a potential absolute imaging reduction of 41.25%. We observed a single false-negative case an isolated subsegmental embolism in an elderly patient whose D-dimer fell just below the algorithm's absolute cutoff, though it would have triggered an age-adjusted threshold. Conclusion: The YEARS algorithm is an incredibly accurate, patient-safe, and resource-efficient diagnostic strategy. In our high-volume tertiary environment, relying on YEARS as a clinical gatekeeper dramatically curtailed unnecessary CTPA scans without compromising diagnostic integrity, making it a vital tool for modern respiratory and emergency triage.