The performance of STA-Liatest D-dimer assay in out-patients with suspected pulmonary embolism

Several studies have shown that d ‐dimer can reliably rule out pulmonary embolism (PE) in out‐patients. However, various assays have different sensitivities and specificities to detect thrombosis. Our aim was to evaluate the performance of STA‐Liatest D‐Di in out‐patients referred for suspected PE in a prospective outcome study. 495 consecutive patients referred to Østfold Hospital Trust‐Fredrikstad, Norway for suspected PE between February 2002 and December 2003, were recruited in a study evaluating a decision‐based algorithm combining clinical probability (CP), d ‐dimer, and multi‐slice computer tomography (MSCT). d ‐dimer was performed as a first step test. No further testing was carried out in patients with d ‐dimer ≤0·4 mg/l and low/intermediate CP. The remaining patients proceeded to MSCT. All patients were followed up for 3 months to assess the 3‐month thromboembolic risk. The final cohort consisted of 432 patients. PE was diagnosed in 102 (23%) patients. At a d ‐dimer cut‐off point of 0·4 mg/l the tests had the highest sensitivity (100%) and specificity (36%). It safely ruled out PE in 120 (28%) patients. Kappa‐coefficients for comparisons versus VIDAS and Asserachrom showed good concordance. STA‐Liatest is a reliable and effective assay that can safely rule out PE in out‐patients with a performance comparable with that of enzyme‐linked immunosorbent assay‐based d ‐dimer levels.