Costs and clinical outcomes after coronary multidetector CT angiography in patients without known coronary artery disease: comparison to myocardial perfusion SPECT.

PURPOSE

To assess costs and clinical outcomes in individuals without known coronary artery disease (CAD) who underwent multidetector computed tomographic (CT) angiography compared with those in matched patients who underwent myocardial perfusion single photon emission computed tomography (SPECT).

MATERIALS AND METHODS

Data were captured from a deidentified, HIPAA-compliant data warehouse. We examined 1-year CAD costs (additional diagnostic coronary testing, CAD hospitalization, and coronary procedural and revascularization costs) and clinical outcomes in individuals without known CAD who underwent multidetector CT (n = 1647) compared with those in a matched cohort of patients who underwent myocardial perfusion SPECT (n = 6588). Cox proportional hazards models were employed for clinical outcome measures, including CAD hospitalization, myocardial infarction, and angina.

RESULTS

Adjusted CAD costs in the multidetector CT group were 25.9% lower than in the myocardial perfusion SPECT group, by an average of $1075 (95% confidence interval [CI]: $243, $2570) per patient. Those in the multidetector CT group were more likely to undergo downstream testing with myocardial perfusion SPECT (odds ratio, 6.65; 95% CI: 5.05, 8.75; P < .001), while those in the myocardial perfusion SPECT group were more likely to undergo downstream testing with invasive angiography (odds ratio, 6.25; 95% CI: 4.35, 9.09; P < .001). The multidetector CT group was less likely to undergo coronary revascularization (hazard ratio, 0.76; 95% CI: 0.75, 0.77; P < .001) than the myocardial perfusion SPECT group. There was no significant difference between multidetector CT and myocardial perfusion SPECT groups for rates of myocardial infarction (0.4% for both) or CAD hospitalization (0.7% vs 1.1%, respectively), while rates of angina were significantly lower in the multidetector CT group (4.3% vs 6.4%, P < .001).

CONCLUSION

Individuals without known CAD who underwent multidetector CT as an initial diagnostic test, compared with those who underwent myocardial perfusion SPECT, incurred lower health care costs with similar rates of myocardial infarction and CAD-related hospitalization.