Background: Traditionally, patients with acute pulmonary embolism (PE) are hospitalised for initial anticoagulant treatment. Out of hospital treatment has increased but there is still great uncertainty as to what is the optimal triaging instrument. BNP testing is a promising simple bedside tool in acute PE, which has not been extensively investigated in this setting.
Aims: To investigate the efficacy and safety of selecting PE patients for outpatient treatment by NT-proBNP testing.
Methods: Randomized non-inferiority trial conducted in the Netherlands. Patients with CT pulmonary angiography proven acute PE were first screened for outpatient treatment eligibility based on the Hestia criteria (Zondag et al JTH 2011). Patients without any of the Hestia criteria were randomized to (1) discharge within 24 hours after diagnosis of acute PE, or (2) additional NT-proBNP testing. Patients in the BNP group were only discharged within 24 hours after diagnosis, if NT-proBNP was ≤500ng/L; they were admitted to the hospital if NT-proBNP was >500ng/L. Primary endpoint was 30-day adverse outcome defined as PE or bleeding-related mortality, cardiopulmonary resuscitation or IC admission. Secondary endpoints were recurrent VTE, major bleeding and all-cause mortality.
Results: Between 2010 and 2013, 550 patients were randomized. In the NT-proBNP group, 34/275 (12%) had elevated NT-proBNP values and were managed as inpatients. The primary endpoint occurred in none of these 275 patients (0%; 95% CI 0–1.3%), versus in 3/275 (1.1%; 95% CI 0.2–3.2%) of the patients in the direct discharge group (p=0.08). These 3 patients had normal NT-proBNP levels measured post-hoc. During 3-month follow-up, recurrent VTE occurred in 2 patients (0.73%; 95% CI 0.1–2.6%) in the NT-proBNP group versus 3 patients (1.1%; 95% CI 0.2–3.2%) in the direct discharge group (p=0.65). The rates of major bleeding were 0.4% vs 1.1% (p=0.62) and of all-cause mortality 1.5% vs 1.1% (p=0.70), respectively.
Conclusion: Prognostic assessment, based on NT-proBNP levels does not affect 30-day prognosis. It changes therapeutic management in only 12% of patients. It is concluded that additional BNP testing is not needed after applying the Hestia decision rule.Whether the same conclusion is valid for BNP testing performed after triaging according to the sPESI rule is currently being analysed and these results will be reported at the ESC congress.