Are CT Angiography Findings Associated with Blood Lactate Levels in Acute Mesenteric Ischemia?

Galit Zlotnik 1,2 Orly Ohana 1,2 Larissa Guranda 1,2 Victor Belsky 1,2 Shelly Soffer 1,2 Nir Horesh 2,3 Alec Krosser 1,2 Eli Konen 1,2 Eyal Klang 1,2 Marianne Michal Amitai 1,2
1Diagnostic imaging, Sheba Medical Center, Israel
2Sackler School of Medicine, Tel Aviv University, Israel
3Department of General Surgery B, Sheba Medical Center, Israel

PURPOSE: Acute Mesenteric Ischemia (AMI) is an abdominal emergency occurring when mesenteric arterial perfusion decreases due to impaired venous drainage or arterial occlusion. Although the serum lactate level is widely used in the assessment of patients presenting with abdominal pain and suspicion of AMI, it is still unclear whether lactate levels correlate with the degree of intestinal ischemia.

The aim of this study was to assess the accuracy of lactate in detecting AMI and in predicting mortality as well as to evaluate the association of lactate with CT angiography (CTA) findings in AMI.

MATERIALS AND METHODS: Consecutive patients who underwent CTA for clinical suspicion of AMI were retrospectively collected (2012-2015). Retrieved data included demographics, lactate levels, final clinical diagnosis, and CTA interpretations. Only patients with a lactate examination performed within eight hours of CTA were included.

Two radiologists reinterpreted in consensus the CTA studies of patients with a clinical or radiological diagnosis of AMI and registered the following imaging findings: bowel wall thickening, unenhanced bowel wall, increased bowel wall enhancement, bowel dilatation, pneumatosis intestinalis, SMA thrombosis, mesenteric stranding, ascites, and solid organ infarction.

ROC curve analysis was used to evaluate the predictive value of lactate for AMI, mortality, and for the presence of CTA findings.

RESULTS: Overall, 320 patients were included in this study, and 33/320 (10.3%) were clinically and radiologically diagnosed with AMI. Although lactate levels were not found to be predictive of AMI (AUC=0.586, p=0.104), lactate had a strong ability to predict mortality in the AMI group (AUC=0.905, p<0.001) and a moderate ability to predict mortality in the entire cohort (AUC=0.662, p<0.001).

None of the evaluated CTA features were associated with elevated lactate (p>0.05 for all features).

CONCLUSION: Although lactate is a strong prognostic factor in AMI, it is not associated with either the presence of AMI or with CTA features of AMI.