Definition of tachycardia for risk stratification of pulmonary embolism

Tachycardia is a reliable predictor of adverse outcomes in normotensive patients with acute pulmonary embolism (PE). However, different prognostic relevant heart rate thresholds have been proposed. The aim of the study was to investigate the prognostic performance of different thresholds used for defining tachycardia in normotensive PE patients.

We performed a post-hoc analysis of normotensive patients with confirmed PE consecutively included in a single-centre and a multi-centre registry. An adverse outcome was defined as PE-related death, need for mechanical ventilation, cardiopulmonary resuscitation or administration of catecholamines.

Of 1567 patients (median age: 72 [IQR, 59-79] years; females: 46.1%) included in the analysis, 78 patients (5.0%) had an in-hospital adverse outcome. The rate of an adverse outcome was higher in patients with a heart rate ≥100 bpm (7.6%) and ≥110 bpm (8.3%) compared to patients with a heart rate <100 bpm (3.0%). A heart rate ≥100 bpm and ≥110 bpm was associated with a 2.7 (95% CI 1.7-4.3) and 2.4-fold (95% CI 1.5-3.7) increased risk for an adverse outcome, respectively. Receiver operating characteristics analysis revealed a similar area under the curve with regard to an adverse outcome for all scores and algorithm (ESC 2019 algorithm, modified FAST and Bova score) if calculated with a heart rate threshold of ≥100 bpm or of ≥110 bpm.

Defining tachycardia by a heart rate ≥100 bpm is sufficient for risk stratification of normotensive patients with acute PE. The use of different heart rate thresholds for calculation of scores and algorithm does not appear necessary.