Prognostic significance of electrocardiogram at presentation in patients with pulmonary embolism of different severity

Background: Several electrocardiographic (ECG) abnormalities have been described in patients with acute pulmonary embolism (PE), with discordant reportings about their prognostic value. Methods: Consecutive patients with echocardiography performed within 48 h from admission and ECG at presentation, were included in this analysis. The primary study outcome was in-hospital death for high-risk patients and in-hospital death or clinical deterioration for intermediate-risk patients. As secondary outcomes, the associations among ECG abnormalities and both right ventricular dysfunction at echocardiography and baseline troponin elevation were considered. Results: 1194 patients were included in this analysis: 13.8% of patients were at high risk of early death, 61.7% were at intermediate risk and 24.5% were at low risk. ECG signs of RV strain showed a continuously decreasing prevalence from high-risk to intermediate-risk and low-risk patients. Differently, the prevalence of T-wave inversion was similar in high and intermediate-risk patients. In high-risk-patients, Qr pattern in lead V-1 was the only ECG abnormality associated with in-hospital mortality, but this sign was detected in only 15.9% of this risk category; the presence of at least one ECG abnormality was not associated with the risk of in-hospital death. In not high-risk patients, the presence of at least one ECG abnormality was significantly associated with RVD and this association was confirmed for each individual ECG abnormality. Similar results were obtained as regards the baseline troponin elevation in 816 patients. Conclusions: Among the electrocardiographic signs of RV strain/ischemia, Qr pattern in lead V-1 was the only ECG abnormality associated with in-hospital mortality in high-risk patients. In not high-risk patients the demonstrated association among baseline ECG signs of RV strain/ischemia and RV dysfunction at echocardiography or troponin elevation highlights the need for early further investigations in patients with such ECG abnormalities.