NORMAL CORONARY ANGIOGRAMS IN PATIENTS OF SUSPECTED CORONARY ARTERY DISEASE: A SIX YEAR STUDY AT ARMY CARDIAC CENTRE LAHORE

Objective: To assess the number of normal coronary angiographies during elective invasive coronary angiography (ICA) in patients with suspected coronary artery disease (CAD). Study Design: Descriptive cross-sectional study. Place and Duration: This study was conducted at Army Cardiac Centre, Lahore, from Jul 2013 to Jul 2019. Methodology: Six-years data of patients undergoing elective invasive coronary angiography without previous percutaneous coronary intervention (PCI) or coronary artery bypass grafting surgery (CABG) was analyzed in this study. The proportion of the patients with significant coronary artery disease were defined as those with at least one lesion of ≥20% stenosis on ICA. The rest of the patients were deemed as normal coronary angiograms. Data was entered and analyzed in SPSS-23. Results: The study consisted of 10260 individuals and after exclusion criteria included 9788 patients, out of which 76.3% were male patients and 23.7% were females. Mean age of the patients was 64 ± 11 years, 8026 (82.4%) patients had a positive noninvasive test out of which exercise stress test was performed on 5377 (67.9%) individuals, stress myocardial perfusion imaging on 2407 (30%) and coronary computed tomography angiogram on 160 (2%) patients. About 1761 (18.1%) patients who were referred did not have any tests before. The overall rate of normal coronary angiographies was 921 (9.4%), lower among those with previous testing (81% vs. 19% without previous testing, p=0.001). A positive test and common risk factors were all independent predictors of obstructive coronary artery disease, with adjusted odds ratios and 95% confidence interval 1.33 (1.03–1.74) for noninvasive testing 1.04 (1.04-1.06) for age, 3.47 (2.81-4.29) for males, 1.86 (1.32-2.62) for smoking, 1.74 (1.38-2.20) for diabetes mellitus, 1.30 (1.04-1.62) for raised cholesterol levels, and 1.39 (1.08–1.80) for hypertensive patient. Conclusions: This study serves to prove a relatively strong gatekeepers; functional tests were more often used but were outperformed by anatomic tests. The much lower rate of normal coronary angiograms is also an indirect indicator of the judicious use of invasive coronary angiography