Canceled coronary computed tomography angiography: Downstream testing and outcomes.

Background: Downstream resource utilization and its impact on outcomes after a canceled CCTA have not been well studied. We sought to understand downstream resource utilization and patient outcomes after canceled CCTA.

Methods And Results: Consecutive patients were prospectively enrolled into an institutional cardiac CT registry. Patients who had the CCTA study canceled because of severe coronary calcification were followed for downstream resource utilization and the composite of all-cause mortality and non-fatal myocardial infarction (MI). 463 patients had their CCTA canceled due to severe coronary calcification and follow-up was available for 453 (97.8%) patients (median follow-up=36.0months). There were a total of 62 events (41 all-cause deaths and 21 non-fatal MI) with an annualized event rate of 4%. Three hundred and twenty patients underwent downstream CAD (ICA or MPI or EST) investigations. Age, NCEP/ATP III risk, beta-blocker use, Agatston and downstream CAD testing were associated with the primary outcome. There were fewer events in those that received downstream CAD testing (30 (9.7%) versus 32 (22.4%)). The annualized event rates for those who did and did not receive downstream CAD testing were 2.8% and 6.2%, respectively. Multivariable analysis confirmed that downstream CAD testing was an independent predictor of event-free survival and that the absence of additional CAD testing was associated with worse outcome (HR: 2.58 (95% CI: 1.54-4.31)).

Conclusions: Patients with canceled CCTA due to severe and/or extensive CAC have high rates of death and non-fatal MI. The use of additional CAD testing appears to be associated with improved outcomes.