Coronary computed tomography angiography in symptomatic patients without obstructive coronary artery disease:Sex-and age-related differences in prognosis

Introduction: Absence of coronary artery disease (CAD) by coronary computed tomography angiography (CTA) is associated with a favorable clinical outcome. However, whether outcomes for patients without obstructive CAD are comparable to prognosis in the general population is unknown. We therefore compared the sex- and agerelated risk of myocardial infarction (MI) or all-cause mortality in patients without or with non-obstructive CAD with that of the general population. Methods: Consecutive patients without known coronary artery disease (CAD) and with chest pain who underwent coronary CTA (>64-detector row) between January 2007 and December 2012 in the 10 centers participating in the Western Denmark Cardiac Computed Tomography Registry were included. Patients were followed for a median (interquartile range [IQR]) period of 2.6 (1.7-3.5) years. During follow-up, MI and death were registered. Coronary CTA results were defined as normal (no luminal stenosis) or non-obstructive CAD (1%-49% luminal stenosis). Each patient was matched by sex, age, and municipality with 10 persons from the general population. Cox regression was used to compute hazard ratios (HRs) with 95% confidence intervals (CIs) as measures of the relative risk of the endpoints, adjusting for age, diabetes, use of lipid-lowering or antihypertensive medications, and comorbidity as assessed by the Charlson Comorbidity index. Results: The study cohort comprised 14,271 patients (median age [IQR]: 57 [49-65]; 58.9% women) and a general population comparison cohort of 142,698 persons. More men than women had non-obstructive CAD (40.5% vs. 30.1%) and more women than men were without CAD (69.9% vs. 59.5%). Women 65 years with no or non-obstructive CAD had lower mortality risks than the general population [HR: 0.37 (95% CI, 0.21-0.67) and HR: 0.48 (0.29-0.78), respectively], but no difference was present regarding the risk of MI. Men without or with CAD did not differ in risk of MI or death, regardless of age, when compared to the general population. Conclusion: Women 65 years without or with non-obstructive CAD have a lower mortality risk than women from the general population. When compared to the general population, men without or with CAD did not, irrespective of age, differ regarding the risk of MI or death.