Troponin Release in Acute Pulmonary Embolism Correlates to Increased Right Heart Volumes on CT Pulmonary Angiography

Rabeeh Fares 1 Yoav Granot 2 Zach Rozenbaum 3 Tomer Ziv-Baran 4 Shlomo Berliner 2 Tamar Shalmon 1 Galit Aviram 1
1Department of Radiology, Tel Aviv Medical Center, Israel
2Department of Internal Medicine, Tel Aviv Medical Center, Israel
3Department of Cardiology, Sheba Medical Center Affiliated to the Sackler School of Medicine, Israel
4Department of Epidemiology and Preventive Medicine, School of Public Health, Sackler Faculty of Medicine, Tel Aviv University, Israel

PURPOSE: Computed tomography pulmonary angiography (CTPA) is currently the modality of choice for the diagnosis of acute pulmonary embolism (PE). It can also be used to calculate the volumes of the right ventricle (RV) and right atrium (RA) in an automated quantitative method. Risk stratification of PE patients is based on imaging and cardiac biomarkers including troponin. We hypothesized that troponin levels correlate with enlarged right sided cardiac chambers` volumes among patients with acute PE.

METHODS: Patients with with acute PE, who underwent CTPA and had a troponin test performed within 72 hours of the CTPA at our center between 2011-2015, were included, and grouped by gender. Using the CTPA data, the volumes of the cardiac chambers indexed to body surface index (BSA) were calculated, and correlated to troponin after adjustment to age and creatinine clearance.

RESULTS: The final cohort consisted of 106 patients with acute PE , 61 females, median age 75, creatinine clearance (mL/min) 68 (54.0-94.9), and 45 males (42%), median age 64, creatinine clearance (mL/min) 81.0 (64.9-94.9). Patients with troponin level at the upper third compared to the lower third, had larger volumes of their RV and RA. Among females RV volumes (median in milliliters/m²) were 80.8 vs. 50 P<0.001; among males 79.8 vs. 62.0, P=0.005). RA volumes: among females 64.5 vs. 40.3, P=0.001; among males 79.8, vs. 42.3, P=0.044). Same for comparison between the middle third of troponin level to the lower third RV (females P=0.003; males P=0.04) and RA (females P=0.036; Males P=0.044).

CONCLUSION: This is the first study to show correlation between elevated troponin and increased volumes of the right cardiac chambers based on CTPA data. Our results may imply that the volumetric assessment of CTPA has the potential to identify patients with acute PE who have stretch-induced troponin release.