Temporal trends in referral patterns for invasive coronary angiography - a multicenter 10-year analysis

Aim To assess the temporal trends in the usage pattern of non-invasive testing before invasive coronary angiography (ICA) and its diagnostic yield in patients with suspected coronary artery disease (CAD). Methods Cross-sectional observational multicenter study of 4805 consecutive patients (60% male, mean age 66 ± 10 years) with suspected CAD undergoing elective ICA due to angina pectoris in two centers, from 2008 to 2017. The use of noninvasive testing and the proportion of patients with obstructive CAD (defined as the presence of at least one ≥50% stenosis on ICA) were assessed. Results There were 4038 (84%) patients referred for ICA with positive noninvasive test, mainly SPECT (38%, n = 1828) and exercise ECG (36%, n = 1731). Obstructive CAD was found in 54.5% (n = 2621) of the patients and 37.9% (n = 1822) underwent revascularization. The prevalence of obstructive CAD was higher in patients with vs. without previous noninvasive testing (55.8% vs. 48.1%, respectively, P < 0.001) and tended to decrease during the study period (P for trend <0.001). Both the presence of obstructive CAD and revascularization rate were higher in patients who underwent anatomical evaluation with CCTA compared with noninvasive functional tests (P = 0.001 and P = 0.018, respectively). The number of patients referred after exercise testing and SPECT decreased (p for trend 0.005 and 0.006, respectively) and after CCTA and stress CMR increased (both P for trend <0.001). The proportion of patients referred without previous testing remained stable. Conclusion Nearly half of the patients undergoing ICA for suspected CAD did not have obstructive coronary lesions. This proportion tended to increase over the 10-year span of this study. Better clinical assessment tools and diagnostic pathways for stable CAD are warranted.