P6462Use of an uniform tachycardia threshold to identify normotensive patients with acute pulmonary embolism at higher risk for adverse in-hospital outcome
Authors: Hobohm L , Becattini C , Keller K , Lerchbaumer M , Ebner M , Konstantinides S , Casazza F , Lankeit M 
Published: October 2019

Abstract

Background
Tachycardia, an early indicator of haemodynamic compromise and RV failure, is a reliable predictor of adverse outcomes in normotensive patients with acute pulmonary embolism (PE). However, different prognostic relevant thresholds have been proposed.

Purpose
To investigate the prognostic performance of different thresholds used for the definition of tachycardia in normotensive PE patients.

Methods
We performed a post-hoc analysis of normotensive patients with confirmed PE consecutively included in a single-centre and a multi-centre registry.

Results
Overall, 1576 PE patients (mean age: 67.7 [IQR, 59–79] years; females: 54.7%) were included in this analysis. During the in-hospital stay, 50 patients (3.2%) had an adverse outcome. The rate of an adverse in-hospital outcome (primary outcome) was higher in patients with a heart rate ≥100 bpm (4.6%) compared to patients with a heart rate of ≥110 bpm (4.1%). Using univariate logistic regression analysis, PE patients with a heart rate ≥100 bpm had an increased risk (OR 2.3 [95% CI 1.1–4.2]; p=0.020) for an adverse in-hospital outcome, while a heart rate of ≥110 bpm did not provide prognostic information (OR 1.5 [95% CI 0.8–2.7]; p=0.083).
Additionally, both threshold defining tachycardia (heart rate ≥100 bpm and ≥110 bpm, respectively) were used for calculation of validated risk stratification scores (modified FAST and Bova score) and algorithm (ESC 2014 based on sPESI). ROC analysis revealed a larger AUC with regard to an in-hospital adverse outcome for all scores and algorithm calculated with a heart rate threshold of ≥100 bpm compared to ≥110 bpm (Table 1). Regardless of the score used, the risk of an in-hospital adverse outcome was highest when a heart rate threshold of ≥100 bpm was used (Table 1).
Table 1. Prognostic performance Sensitivity Specificity PPV NPV OR (95% CI) AUC (95% CI) p-value p-value Mod. FAST score (HR ≥110) 0.36 (0.24–0.50) 0.76 (0.74–0.78) 0.05 (0.03–0.07) 0.97 (0.96–0.98) 1.8 (1.0–3.3) 0.63 (0.56–0.70) p=0.046 p=0.002 Mod. FAST score (HR ≥100) 0.54 (0.40–0.67) 0.68 (0.65–0.70) 0.05 (0.04–0.07) 0.98 (0.97–0.99) 2.5 (1.4–4.3) 0.64 (0.56–0.72) p=0.002 p=0.001 Bova score (HR ≥110) 0.28 (0.17–0.42) 0.82 (0.80–0.84) 0.05 (0.03–0.08) 0.97 (0.96–0.98) 1.7 (0.9–3.3) 0.63 (0.56–0.70) p=0.083 p=0.002 Bova score (HR ≥100) 0.48 (0.35–0.61) 0.74 (0.72–0.77) 0.06 (0.04–0.08) 0.98 (0.97–0.98) 2.7 (1.5–4.7) 0.68 (0.62–0.75) p=0.001 p<0.001 ESC 2014 incl. sPESI (HR ≥110) 0.62 (0.49–0.74) 0.64 (0.62–0.67) 0.05 (0.04–0.07) 0.98 (0.97–0.99) 3.1 (1.7–5.6) 0.64 (0.57–0.72) p<0.001 p=0.001 ESC 2014 incl. sPESI (HR ≥100) 0.60 (0.67–0.72) 0.70 (0.67–0.72) 0.06 (0.04–0.09) 0.98 (0.97–0.99) 3.4 (1.9–6.1) 0.67 (0.59–0.74) p<0.001 p<0.001

Conclusions
Defining tachycardia by a heart rate of ≥100 bpm, as generally recommended, is sufficient for risk stratification of normotensive patients with acute PE and improves the identification of PE patients at higher risk of PE-related complications. The use of different thresholds for calculation of scores does not appear necessary.

Acknowledgement/Funding
This study was supported by the German Federal Ministry of Education and Research (BMBF 01EO1503).