Recognition of unprovoked (idiopathic) pulmonary embolism – prospective observational study.

Background: The assessment of the clinical symptoms is the weakest link of the pulmonaryembolism (PE) diagnostic algorithm. Despite the presence of highly sensitive and specificimaging methods, verifying PE remains difficult due to nonspecific clinical symptoms andfrequently its subclinical course.Objective: The aim of this study is to improve the recognition of PE by investigating the clinicalpresentation and short-term prognosis of unprovoked PE in comparison to provoked PE. Thestudy was directed to patients who suffer from PE as a primary disease.Methods: This prospective observational study included 331 patients with PE, approved bycomputer tomographic pulmoangiography. They were categorized as having unprovoked orprovoked PE, according to their epidemiological data. The clinical characteristics and one-monthmortality rate were compared between both groups.Results: About 67% of the patients had provoking factors and ~33% had unprovoked PE. Thepatients in the unprovoked PE-group were younger compared to provoked PE-group(56.67±17.95 vs 63.76±14.58, p<0.0001) and the males predominated vs females (62.04% vs37.96%, p=0.012). The patients with unprovoked PE had more previous thromboembolic eventscompared to provoked PE-group (30.56% vs 19.45%, p=0.022) and a larger thrombotic burden(p=0.001). Dyspnea (85.18% vs 85.13%), chest pain (47.22% vs 46.85%), cough (43.92% vs45.94%), hemoptysis (16.67% vs 14.41%), hemodynamic instability (9.26% vs 8.56%), deepvenous thrombosis (49.51% vs 44.5%) had similar frequencies in both groups. No significantdifferences in the means of systolic pressure of arteria pulmonalis, D-dimer, arterial blood gases,Revised Geneva probability score were found. One-month mortality was lower in unprovokedPE-group than in provoked (1.85% vs 8.52%, p=0.042).Conclusions: Unprovoked PE occurs at a younger age, more frequently in males. It ischaracterized by the following significant variables: higher Wells score, lower PESI score, lowerCRP, higher thrombotic burden and lower one-month mortality rate, compared to provoked PE