McConnell's sign predicts normotensive shock in patients with acute pulmonary embolism

Abstract

Abstract Funding Acknowledgements None. Background Patients with intermediate-risk acute pulmonary embolism (PE) have mortality rates ranging from 3-15%, with incidence of normotensive shock occurring in up to 30% of patients.1-3 Existing risk models often fall short in accurately identifying those at heightened risk of normotensive shock and those who might derive benefit from advanced therapeutic interventions including catheter based therapies. Diagnosis of normotensive shock typically necessitates invasive right heart catheterization, however, McConnell's sign has been associated with higher risk PEs.4 Consequently, our objective was to assess the relationship between McConnell's sign, a readily available bedside point-of-care tool, and its predictive value in identifying normotensive shock in patients diagnosed with acute intermediate-risk PE. Methods All patients with intermediate-risk PE who underwent percutaneous mechanical thrombectomy (MT) between August 2020 and April 2023 at a large academic public hospital were included in the study. Normotensive shock was defined as patients with systolic blood pressure (SBP) ≥ 90mmHg in the absence of vasopressor support with pre-procedural invasive measures of CI £ 2.2 L/min/m2 and clinical evidence of hypoperfusion (i.e. elevated lactate, oliguria). The primary outcome was the association between McConnell’s sign and normotensive shock. Results A total of 49 patients with intermediate-risk PE underwent MT, 9 patients had incomplete data, resulting in a final cohort of 40 patients (mean age: 57 ± 13 years; 45% female). A total of 29/40 (72.5%) patients had McConnell’s sign. Patients with McConnell’s sign had higher rates of obesity (59% vs 18% p=0.02), higher heart rate (114 vs 99 beats/min, p=0.008), higher rates of elevated lactate (86% vs 55%, p=0..038), lower cardiac index (1.9 vs 3.1 L/min/m2, p=0.003), and higher rates of normotensive shock (76% vs 27%, p=0.005). There was no statistically significant difference in age, sex, race, rates of saddle emboli, left ventricular ejection fraction, pulmonary artery systolic pressure, presenting blood pressure, sPESI and composite pulmonary embolism shock score scores in patients with or without McConnell’s sign. In patients with normotensive shock, 22/25 (88%) had McConnell’s sign and only 53.3% had McConnell’s sign without shock (Figure 1). Patients with McConnell’s sign had an increased odds (OR 8.38, CI: 1.73-40.53; p=0.008, AUC 0.70, 95% CI: 0.56-0.85) of normotensive shock. Conclusion This is the first study to suggest that McConnell’s sign can effectively identify those in the intermediate-risk group who are at risk for normotensive shock. Further studies are needed to validate this non-invasive technique that can be rapidly performed at bedside with high reproducibility and whether it can help risk-stratify patients who may benefit from advanced PE therapies.