Coronary CT angiography (CCTA) is used in patients with low-intermediate
chest pain presenting to the emergency department for its reliability in excluding
acute coronary syndrome (ACS). However, its influence on medication modification in this setting is unclear. We sought to determine whether knowledge of CCTA-based
coronary artery disease (CAD) was associated with change in
statin and
aspirin prescription. We used the CCTA arm of the Rule Out
Myocardial Infarction using Computed Angiographic Tomography II multicenter, randomized control trial (R-II) and comparison cohort from the observational Rule Out
Myocardial Infarction using Computed Angiographic Tomography I cohort (R-I). In R-II, subjects were randomly assigned to CCTA to guide decision making, whereas in R-I patients underwent CCTA with results blinded to caregivers and managed according to standard care. Our final cohort consisted of 277 subjects from R-I and 370 from R-II. ACS rate was similar (6.9% vs 6.2% respectively, p = 0.75). For subjects with CCTA-detected obstructive CAD without ACS, initiation of
statin was significantly greater after disclosure of CCTA results (0% in R-I vs 20% in R-II, p = 0.009). Conversely, for subjects without CCTA-detected CAD,
aspirin prescription was lower with disclosure of CCTA results (16% in R-I vs 4.8% in R-II, p = 0.001). However, only 68% of subjects in R-II with obstructive CAD were discharged on
statin and 65% on
aspirin. In conclusion, physician knowledge of CCTA results leads to improved alignment of
aspirin and
statin with the presence and severity of CAD although still many patients with CCTA-detected CAD are not discharged on
aspirin or
statin. Our findings suggest opportunity for practice improvement when CCTA is performed in the emergency department.