Object: Few studies have addressed the prognostic implications of D-dimer in patients with pulmonary embolism. The aim of this study was to investigate the correlation between D-dimer levels and mortality in patients with pulmonary embolism.
Design: Observational study.
Setting: Hospitals participating in the Registro Informatizado de la Enfermedad Tromboembólica (RIETE).
Patients: A total of 588 consecutive patients with symptomatic pulmonary embolism who were included in the RIETE between March 2001 and December 2004.
Interventions: Quantitative D-dimer measurement was performed on admission using an automated latex agglutination test (IL Test D-dimer). All patients underwent clinical follow-up for 3 months.
Measurements and main results: Overall mortality rate was 10.5%. The cause of death was pulmonary embolism in 18 patients (3.0%), fatal bleeding in one patient (0.2%), and other causes in 43 patients (7.3%). There were 28 (4.8%) nonfatal venous thromboembolism recurrences and 35 (6.0%) nonfatal bleeding episodes. The incidence of D-dimer 500-2499 ng/mL, D-dimer 2500-4999 ng/mL, and D-dimer >or=5000 ng/mL was 47.8%, 26.0%, and 20.4%, respectively. Compared with patients with D-dimer 500-2499 ng/mL, the relative risk (odds ratio) of overall mortality was 1.91 (95% confidence interval 0.91-4.09) and 2.94 (95% confidence interval 1.42-6.25) in patients with D-dimer 2500-4999 ng/mL and D-dimer >or= 5000 ng/mL, respectively (p = .032). Patients with D-dimer >or=5000 ng/mL showed higher risk of death from fatal pulmonary embolism (odds ratio 4.4, 95% confidence interval 0.5-33.0) than death from other causes (odds ratio 2.1, 95% confidence interval 0.7-6.0). Elevated D-dimer levels were associated with more severe disease, as assessed by clinical features.
Conclusions: In patients who present with pulmonary embolism, D-dimer concentration is an independent predictive factor associated with all-cause and pulmonary embolism-related death. D-dimer >or=5000 ng/mL occurs in about one in five patients and is associated with a 2.9-fold increased risk of overall mortality. These results suggest that D-dimer quantification could be a useful biomarker and help determine initial therapies.