Aims Although it is accepted that atrial fibrillation (AF) may be both the contributing factor and the consequence of pulmonary embolism (PE), data on the prognostic role of AF in patients with acute venous thromboembolism are scarce. Our aim was to study whether AF had a prognostic role in patients with acute PE.

Methods Retrospective cohort study involving 270 patients admitted for acute PE. Collected data: past medical history, analytic/gasometric parameters, admission ECG and echocardiogram, thoracic CT angiography. Patients followed for 6 months. An analysis was performed in order to clarify whether history of AF, irrespective of its timing, helps predict intrahospital, 1-month and 6-month all-cause mortality.

Results Patients with history of AF, irrespective of its timing (n=57, 21.4%), had higher intrahospital (22.8% vs 13.1%, p=0.052, OR 2.07, 95% CI 0.98 to 4.35), 1-month (35.1% vs 16.9%, p=0.001, OR 3.16, 95% CI 1.61 to 6.21) and 6-month (45.6% vs 17.4%, p<0.001, OR 4.67, 95% CI 2.37 to 9.21) death rates. The prognostic power of AF was independent of age, NT-proBNP values, renal function and admission blood pressure and heart rate and additive to mortality prediction ability of simplified PESI (AF: p=0.021, OR 2.31, CI 95% 1.13 to 4.69; simplified PESI: p=0.002, OR 1.47, CI 95% 1.15 to 1.89). The presence of AF at admission added prognostic value to previous history of AF in terms of 1-month and 6-month all-cause mortality prediction, although it did not increase risk for intrahospital mortality.

Conclusions The presence of AF, irrespective of its timing, may independently predict mortality in patients with acute PE. These data should be tested and validated in prospective studies using larger cohorts.