PB0934 - Venous lactate as a tool for the risk-stratification of patients with acute pulmonary embolism: a two-center retrospective cohort study

Monday, June 24, 2024

13:45 – 14:45 ICT

Room: Exhibition Hall

Presenting Author(s)

Eun Sang Lee

Research Collaborator, Center for Vascular Emergencies
Massachusetts General Hospital
Dublin, Dublin, Ireland

Co-Author(s)

PK

Paige Koetter MD

Resident Physician, VUMC Emergency Department
Vanderbilt University Medical Center
Nasville, Tennessee, United States
WS

William-May B. Stubblefield

Emergency Physician and Assistant Professor
Department of Emergency Medicine, Vanderbilt University Medical Center, Nashville, Tennessee, USA
Nashville, Tennessee, United States
KS

Karsten Stannek

Research Collaborator, Center for Vascular Emergencies
Massachusetts General Hospital
Dusseldorf, Nordrhein-Westfalen, Germany
JW

Jesse O. Wrenn MD PhD

Attending Physician and Assistant Professor, VUMC Emergency Medicine
Vanderbilt University Medical Center
Nashville, Tennessee, United States
GP

Gregory Peters MD

Resident Physician, Harvard Affiliated Emergency Medicine Residency Program
Massachusetts General Hospital
Boston, Massachusetts, United States
DB

Drew Birrenkott DPhil MD

Resident Physician, Harvard Affiliated Emergency Medicine Residency
Massachusetts General Hospital
Boston, Massachusetts, United States
TM

Timothy Matthews BS

Research Collaborator, Center for Vascular Emergencies
Massachusetts General Hospital
Boston, Massachusetts, United States
Christopher Kabrhel, MD MPH

Director, Center for Vascular Emergencies
Massachusetts General Hospital
Boston, Massachusetts, United States

Background: Current guidelines cite arterial lactate as a predictor of respiratory failure and death, but in the emergency department (ED), venous lactate is easier to obtain. There is limited data that guides interpretation of venous lactate values in ED patients with acute PE.

Aims: To determine optimal venous lactate cutoff for the risk-stratification of ED patients with acute PE.

Methods: We performed a two-center, retrospective cohort study of patients with imaging-confirmed PE and venous lactate measured clinically within 24 hours. Data collection was approved by institutional review boards at MGH and VUMC. MGH culled data from its PERT registry, and thus represented patients of greater concern. VUMC data included all patients in its medical record regardless of severity. We excluded hypotensive patients, for whom biomarker risk-stratification is unnecessary. Given differences in selection of patients across centers, we analyzed data from MGH and VUMC separately. Our outcome was acute deterioration, defined as a composite of death, catheter-based intervention, systemic thrombolysis, ECMO, and intubation within 7 days. A Receiver-Operating Characteristic (ROC) curve analysis was performed. Area-under-curve (AUC) reflects lactate performance, and optimal cutoff value was found via least distance from perfect classification point (0,1).

Results: We included 145 patients (MGH) and 1160 patients (VUMC). The mean age was 64 and 58 years. For the outcome, the AUC was 0.56 (95%CI: 0.44-0.67) for the MGH cohort and 0.69 (95%CI: 0.65-0.73) for the VUMC cohort. In MGH, the optimal cutoff was 1.8mmol/L, which corresponds to 58% sensitivity and 61% specificity. In VUMC, the optimal cutoff was 2.0mmol/L, which corresponds to 58% sensitivity and 72% specificity.

Conclusion(s): We observed an inter-cohort discordance in the analyzed AUC. The disagreement most likely arises from fundamental differences between the studied patient cohort. Nonetheless, our data indicates that on its own, venous lactate is a suboptimal tool for PE risk stratification.