D-dimer as a diagnostic and prognostic plasma biomarker in patients with a first episode of acute pericarditis

Objectives: The impact of plasma biomarkers on diagnosis and prognosis of patients with acute pericarditis (AP) has been poorly investigated. This study aims to assess the diagnostic and prognostic role of d-dimer (DD), an easily obtainable biomarker, in patients with AP.

Patients and methods: This is a prospective clinical study enrolling 265 consecutive patients hospitalized between September 2010 and May 2019 with a first episode of AP. At baseline, demographics, clinical features, laboratory and imaging findings were recorded. All patients were followed-up for a minimum of 18 months. Endpoints included cardiac tamponade, new-onset atrial fibrillation, pericardial drainage, recurrent/constrictive pericarditis and death.

Results: DD was measured in 165 out of 265 patients (62.3%, median levels 1456 ng/mL) Among them, 121 patients (73.3%) presented with elevated age-adjusted DD levels. Patients with elevated DD depicted a higher rate of pleural (69.4%, vs 38.6%, p<0.001) and pericardial effusions (89.3% vs 72.7%, p = 0.009). Elevated DD correlated with admission (rho=0.37) and peak (rho=0.36) C-reactive protein values. Patients with elevated DD depicted a trend towards a greater prevalence of pericardial tamponade vs those without (14.9% vs 4.5% respectively, p = 0.07). In the 43.8% of patients with elevated DD who underwent computed tomography pulmonary angiography (CTPA), no case of pulmonary embolism or aortic syndrome was unveiled.

Conclusion: DD elevation is detected in the majority of AP cases at presentation and may herald cardiac tamponade. In patients with chest pain not attributable to alternative causes, elevated DD denotes an inflammatory condition and should not prompt unnecessary investigations, such as CTPA.