What proportion of patients with chest pain are potentially suitable for computed tomography coronary angiography?

Objectives: Serial electrocardiographic and biomarker data are used to rule out acute coronary syndrome (ACS) in emergency department (ED) patients with chest pain. These do not identify coronary artery disease (CAD). Functional tests are often used but have limitations. Multislice computed tomography coronary angiography (MSCT-CA) is evolving rapidly, raising the possibility of fast, accurate, and relatively noninvasive anatomical testing for CAD. We aimed to quantify the proportion of ED rule-out ACS patients suitable for MSCT-CA.

Methods: This retrospective cohort study (by explicit record review) included adult patients who underwent a rule-out ACS process in ED-associated short-stay units. Data collected included demographics, electrocardiographic and biomarker data, contraindications/factors likely to make MSCT-CA unsuccessful or difficult to interpret including irregular heart rhythm, high pulse rate (with rate control contraindicated), renal or thyroid disease, contrast allergy, metformin use, pregnancy, and already confirmed CAD. Outcome of interest was the proportion of patients suitable for MSCT-CA. Data analysis is by descriptive statistics.

Results: Four hundred sixty patients were studied (63% male; median age, 63 years). Forty-nine percent (224/460; 95% confidence interval, 44%-53%) were suitable for MSCT-CA. One hundred eighty-one (39%) already had known CAD. Reasons for unsuitability of the remainder were metformin use 18 (6%), irregular heart rhythm 15 (5%), renal dysfunction 12 (4%), high pulse rate with contraindications to rate control 8 (3%), thyroid disease 7 (3%), and contrast allergy 2 (0.7%).

Conclusion: Approximately half of ED patients with chest pain who have underwent ACS rule-out were potentially suitable for MSCT-CA to identify CAD. The best use of MSCT-CA in the investigation of patients with chest pain requires further clarification.