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

Background: Patients with intermediate-risk pulmonary embolism (PE) and normotensive shock may have worse outcomes. However, diagnosis of normotensive shock requires invasive hemodynamics. Our objective was to assess the predictive value of McConnell's sign in identifying normotensive shock in patients with intermediate-risk PE.

Methods: Patients with intermediate-risk PE who underwent percutaneous mechanical thrombectomy between August 2020 and April 2023 at a large academic public hospital were included in the study. Normotensive shock was defined as systolic blood pressure ≥ 90 mmHg without vasopressor support with pre-procedural invasive measures of cardiac index ≤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: Those with McConnell's sign (29/40, 72.5 %) had 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). McConnell's sign had a sensitivity of 88 % and specificity of 53 % for identifying intermediate-risk PE patients with normotensive shock. Patients with McConnell's sign had an increased odds (odds ratio 8.38, confidence interval: 1.73-40.53, p = 0.008; area under the curve 0.70, 95 % confidence interval: 0.56-0.85) of normotensive shock.

Conclusion: This is the first study to suggest that McConnell's sign may identify those in the intermediate-risk group who are at risk for normotensive shock. Larger cohorts are needed to validate our findings.