Document Type


Publication Date



Maine Medical Center, Medical Education, MaineHealth Institute for Research, Pulmonology

MeSH Headings

Humans, Pulmonary Embolism, Biomarkers, Acute Disease


Purpose/Background Pulmonary embolism (PE) is a major cause of morbidity and mortality. The rate of hospitalization for PE has doubled in the past decade, and it is now the third most common cause of cardiovascular disease after MI and stroke. Early, accurate risk stratification can guide appropriate management and has the potential to improve clinical outcomes. Patients with PE are stratified as being low, intermediate, or high risk for early mortality based on the European classification system which takes into account clinical, imaging, and laboratory parameters. This strategy is recommended to reduce use of potentially harmful therapies, such as systemic thrombolysis and embolectomy, and to restrict use to patients with the greatest chance of benefit. Although there is clarity around management of high and low risk patients, the guidelines for managing intermediate risk patients are less clear. Routine use of thrombolysis in this group is not recommended due to lack of a mortality benefit and a potentially increased risk of adverse events. However, some of these patients will become hemodynamically unstable in the first 24-36 hours leading to a delayed diagnosis of high risk PE. This uncertainty in management may be due to a lack of accurate prognostication tools for short-term adverse outcomes in this intermediate risk group. A tool is needed to identify those who may benefit from more intensive treatment. Given this critical gap in knowledge, the short-term goal of this project is to better understand the natural course of PE biomarkers, including NT proBNP, troponin, lactate, and uric acid. The long-term goal, which will be the subject of future studies, is to use longitudinal biomarker measurements to improve our ability to identify patients at intermediate risk who could benefit from thrombolysis or other advanced therapies. For the present study, we hypothesize that among patients with intermediate risk PE, serial measurements of biomarkers during the first 72 hours will demonstrate different patterns of change between patients who remain at lower risk and those who develop delayed high risk PE.

Methods We propose an observational pilot study to evaluate serial biomarkers in newly diagnosed patients with intermediate risk PE. Intermediate risk PE is defined as right ventricular dysfunction on imaging or positive cardiac biomarkers (NT proBNP or troponin) without hemodynamic compromise.

Specific aims: 1. To characterize temporal trends of biomarkers from measurements taken every 8 hours in 72 hours after diagnosis. 2. To explore the relationship of hemodynamic changes and escalation of management with serial biomarker patterns. Changes over time will be explored, using Pearson’s or Spearman’s correlation as appropriate. Each analyte will be plotted, by patient, over time so that we can visually identify trends in biomarker levels. We will analyze peak abnormal values, time to peak, time to resolution, and area under curve.

Results Work in progress.

Conclusions Understanding changes in biomarkers can assist in designing future studies to better prognosticate and manage patients with intermediate risk PE.


2020 Costas T. Lambrew Research Retreat