Outcomes of Hospitalized Patients With Fecal Occult Positive Stool Prior to Cardiac Catheterization in Acute Coronary Syndrome (ACS)

Introduction Cardiac catheterization is an essential component of patient care in Acute Coronary Syndrome (ACS). Fecal occult blood testing (FOBT) has been used in the inpatient setting to evaluate the risk of bleeding with dual anti-platelet therapy prior to cardiac catheterization although no guidelines exist for this indication and FOBT testing in the inpatient setting is not recommended for evaluation of GI blood loss. We sought to assess the outcomes of patients with fecal occult positive stool prior to cardiac catheterization compared to those that did not undergo FOBT during admission for non-ST-elevation myocardial infarction (NSTEMI). Methods We identified patients between 18 and 90 years old with admission for NSTEMI in the Trinetx Research Network from January 1, 2019 to December 31, 2020. Patients were then divided into those who had an FOBT prior to cardiac catheterization and those that did not have an FOBT. We compared all-cause mortality, bleeding, troponin levels, and length of stay between propensity-matched (PSM) pairs of patients. Results We identified 46,349 that met inclusion criteria, of which 1,728 had an FOBT (3.7%) and 44,621 (96.3%) had no FOBT prior to cardiac catheterization. Patients in the FOBT group were older and had a higher prevalence of hypertension, coronary artery disease, heart failure, diabetes, chronic obstructive pulmonary disease, and higher BMI. Two well-matched groups of n=1,728/1,728 were used for comparing outcomes. The FOBT group had similar 30-day mortality (4.45% vs 4.01, P=0.56) as well as similar bleeding events (0.98% vs 0.69%, P=0.35). Troponin levels in the FOBT group were on average lower (0.41 vs 0.95, P=0.04). The FOBT groups also had a similar average length of stay of (14.1 days vs 14.2 days, P=0.42). 233 patients who received FOBT underwent endoscopic evaluation with either upper endoscopy or colonoscopy (13.5%), and there was no significant difference in 30-day mortality (6.86% vs 4.7%, P=0.321). Among patients who underwent endoscopy, 72 had some form of endoscopic intervention (30.9%). There was no difference in 30-day mortality between patients undergoing endoscopy with intervention and without intervention (14.49%/14.49%) P=1.00. Readmission was similar between patients undergoing endoscopy with and without intervention. Conclusions In a large multi-center national database, we observed similar outcomes in patients who were admitted with NSTEMI and had FOBT and those not receiving FOBT in terms of all-cause mortality and bleeding events. In patients with positive FOBT, endoscopy with and without intervention we observed no significant difference in 30-day mortality. We conclude that there is no compelling evidence for FOBT testing in patients with NSTEMI.