Symptoms and angiographic findings of patients undergoing elective coronary angiography without prior stress testing.

Many patients undergo elective coronary angiography without preprocedural stress testing that may be suitable if performed in patients with more angina pectoris or more frequently identified obstructive coronary artery disease (CAD). Patients in the National Cardiovascular Data Registry CathPCI Registry undergoing elective coronary angiography from July 2009 to April 2013 were assessed for differences in angina (Canadian Cardiovascular Society [CCS] class) and severity of obstructive CAD in those with and without preprocedural stress testing, stratified by CAD history. Given the large sample size, differences were considered clinically meaningful if the standardized difference (SD) was >10%. Of 790,601 patients without CAD history, 36.9% did not undergo preprocedural stress testing. Compared with patients with preprocedural stress testing, patients without preprocedural stress testing were more frequently angina free (CCS class 0; 28.2% with stress test vs 38.5% without, SD = 14.8%) and had similar rates of obstructive CAD (40.1% with stress test vs 35.7% without, SD = 9.0). Of 449,579 patients with CAD history, 44.2% did not undergo preprocedural stress testing. Patients without preprocedural stress testing reported more angina (CCS class III/IV angina: 17.8% vs 13.4%; SD = 11.3%) but were not more likely to have obstructive CAD (78.7% vs 81.1%; SD = 5.8%) than patients with preprocedural stress testing. In conclusion, approximately 40% of patients undergoing elective coronary angiography did not have preprocedural risk stratification with stress testing. For these patients, the clinical decision to proceed directly to invasive evaluation was not driven primarily by severe angina and did not result in higher detection rates for obstructive CAD.