In this analytical prospective study 498 patients over 40 years with any cardiovascular symptoms and without pre-established coronary artery disease ( CAD) were enrolled. Patients underwent CT scans to measure coronary artery calcium score (CACS), and total calcium scores were recorded. Then, conventional coronary angiography was performed for all the participants as the gold standard for diagnosing CAD (defined as at least one stenotic coronary artery with ≥ 50%). Framingham risk score (FRS) was also estimated for all the patients

In this prospective study 498 patient who referred to cardiology clinic with any cardiac symptoms and positive noninvasive tests without preestablished coronary artery disease ( CAD), were enrolled. All the patients underwent coronary artery calcium score (CACS) testing, and total calcium scores were recorded. A calcium score of zero was considered as having very low risk for CAD. A score of 1 to 99 was defined as having low risk, 101 to 299 as having intermediate risk, and 400 or more as having high risk for CAD. Then, invasive (conventional) coronary angiography by radial access, as the gold standard for the diagnosis of CAD, was performed for all of the involved participants.

Coronary artery stenosis equal to or more than 50% was considered as a significant narrowing [25]. Patients with at least one diseased coronary artery with a significant narrowing were considered to have CAD. Minor branches were considered only if their main supplying branch was not diseased. A group of expert interventional cardiologists performed and reported coronary angiographies. The study was single-blind; cardiologists were unaware of the results of CAC scores when performing conventional coronary angiographies

Inclusion Criteria:

• Age over 40 years, having cardiovascular symptoms (including chest pain, dyspnea on exertion, etc.), and positive primary non-invasive tests, such as myocardial perfusion imaging (MPI) or exercise tolerance test (ETT)

Exclusion Criteria:

• Previously diagnosed coronary artery disease
• Cerebrovascular accident (CVA)
• Peripheral artery disease
• Pregnancy
• Medical instability
• Hypersensitivity to contrast materials
• Having atrial fibrillation

Patient with any cardiac symptoms with positive noninvasive tests referred to cardiology clinic with positive non invasive tests like exercise test or echocardiography or perfusion cardiac scan

The data is available in registry and will be available on rational request