Carbonated Soda with Myocardial Perfusion Imaging Do We Really Need it?

Background: Myocardial perfusion imaging (MPI) evaluates coronary perfusion at the cellular level and plays an important role in the diagnosis, assessment of therapy, viability and prognosis of patients with coronary artery diseases. However, artifacts particularly related to gastric tracer accumulation can degrade the quality of the study and negatively influence patients related treatment decisions.

Objectives: This study aimed to examine the impacts of preparing MPI patients with decaffeinated carbonated soda targeting the image quality and treatment decisions for patients with cath. proven coronary artery disease. Methodology: 100 patients referred for MPI between January 2010 and June 2016 and subjected to diagnostic and/or therapeutic catheterization within 3 weeks of their MPI studies at King Faisal Specialist Hospital and Research Center (KFSHRC), Jeddah, Saudi Arabia were retrospectively selected. Demographic data, pre-imaging preparation, MPI study and catheterization results of each patient were collected from patients’ electronic health records. 50 patients prepared with decaffeinated carbonated soda pre-imaging were selected as Group-I. Another 50 patients classically prepared with water and or milk comprised Group-II. The sensitivity, specificity, positive predictive values and negative predictive values were used to investigate the associations between pre-imaging drink types and patients’ MPI study and catheterization results. Subgroup analysis for type of stress weather pharmacologic or treadmill exercise was also performed. Results: For all patients of Group I the sensitivity, specificity, positive predictive values and negative predictive values were 90%, 45%, 50% and 87% respectively Those of Group II they were: 83%, 31%, 40% and 76%. The difference was more pronounced with subgroup analysis as patients sent for pharmacologic stress and prepared with decaffeinated carbonated soda showed sensitivity, specificity, positive predictive values and negative predictive values of 89%, 50%, 55% and 86% respectively compared to 81%, 29%, 32%, and 80% for patients prepared without soda. This difference with not seen for treadmill stress patients because of small number and the physiologic decreased splanchnic blood flow. Conclusion: Preparing MPI patients with decaffeinated soda diminishes interfering sub-diaphragmatic related overlapping gastric activity, resulting in more accurate treatment decision for patients with CAD. Results are more pronounced for patients selected for pharmacologic stress. A larger number of patients in a prospective randomized study is needed to determine the statically significance value as well as the time and amount of decaffeinated carbonated soda needed for different patients conditions.