Abstract 251: Clinical Symptoms and Angiographic Findings of Patients Undergoing Percutaneous Coronary Intervention without Prior Stress Testing: Insights from the NCDR

Abstract

Background: Many patients undergoing elective percutaneous coronary intervention (PCI) do not have prior stress testing. It is unknown if these patients have more severe angina or obstructive coronary artery disease (CAD), whereby proceeding directly to PCI would represent sound clinical judgment and efficient use of resources. Methods: We identified elective PCIs performed between 1/1/09 - 3/31/11 in the NCDR CathPCI Registry ® and assessed for differences in angina (CCS class) and severity of CAD in those with and without pre-procedural stress testing. To further understand whether proceeding to PCI without prior stress testing could be justified because of a high pre-test probability for obstructive CAD (e.g., >70% stenosis in an epicardial coronary artery), we evaluated cardiac catheterizations performed within the registry during the same period to assess the diagnostic yield of obstructive CAD in patients with and without prior stress testing. Results: Of 246,629 elective PCIs, 89,084 (36.1%) were performed without prior stress testing. A substantial proportion of both groups undergoing PCI were asymptomatic (no stress test group: 28.9% vs. stress test group: 30.7%), with only a modest difference in the frequency of CCS class III/IV angina (16.2% vs. 11.9%; Table). No meaningful differences in the frequency of proximal LAD (29.7 % vs. 29.9%), left main (5.6% vs. 7.2%) or 3-vessel coronary artery disease (21.1% vs. 19.5%) were observed in the 2 PCI groups. Moreover, the diagnostic yield for obstructive CAD on cardiac catheterization for patients without prior stress testing (n=462,611) was 35.4%, as compared with 58.0%, 38.8%, and 24.1% for those with severe, moderate, and mild ischemia, on pre-procedural stress testing. Conclusion: For elective PCI, the current practice of proceeding to coronary angiography and PCI without prior stress testing does not identify higher risk coronary anatomy or more symptomatic patients and may not improve diagnostic yield.