Optimal Evaluation to Reduce Imaging Testing (OPERATE)

In daily clinical routine, the evaluation of new-onset and stable chest pain (SCP) suggestive of chronic coronary syndrome (CCS) remains a challenge for physicians. Although coronary computed tomography angiography (CCTA) seems to be the first-line cardiac imaging testing (CIT) according to the recommendations from current guidelines, the optimal diagnostic strategy to identify low risk patients who may derive minimal benefit from further CIT is the cornerstone of clinical management for SCP. Recently, different diagnostic strategies were provided to effectively defer unnecessary CIT, but few studies have prospectively determined the actual effect of applying these strategies in clinical practice. Therefore, the OPERATE study was designed to compare the effectiveness and safety of two proposed diagnostic strategies in identification of low risk individual who may derive minimal benefit from CCTA among patients with SCP suggestive of CCS in a pragmatic randomized controlled trial (RCT).

OPERATE trial was an investigator-initiated, multicenter, prospective, CCTA-based, 2-arm 1:1 parallel-group, double-blind and pragmatic RCT planned to include 800 subjects with SCP suggestive of CCS. Subjects were assigned randomly to two groups: 1) 2016 National Institutes for Clinical Excellence guidelines-determined diagnostic strategy (NICE strategy) and 2) 2019 European Society of Cardiology guidelines-determined diagnostic strategy (ESC strategy) The primary objective of OPERATE trial is to compare the rates of CCTA without obstructive CAD according to NICE and ESC strategy. The key secondary objective is to assess whether the two strategies have no significant difference in terms of major adverse cardiac events (MACE). The investigators hypothesize that when comparing with NICE strategy, ESC strategy which sequentially incorporated the ESC-PTP model with RF-CL model will decrease the probability of CCTA without obstructive CAD but not at the expense of safety and cost over a follow-up period of 1 year.

Stable Chest Pain, Pretest Probability, Coronary Computed Tomography Angiography, Diagnostic Strategy, Coronary Artery Disease

ESC-PTP is calculated using age, sex and type of chest pain according to 2019 ESC guideline for the diagnosis and management of CCS and RF-CL is calculated using age, sex, type of chest pain, hypertension, dyslipidemia, diabetes, smoking and family history of CAD based on the publication of Winther et al., respectively. According to ESC strategy, subjects with ESC-PTP ≤5% are classified into low risk group and ones with ESC-PTP ≥15% are classified into high risk group. For subjects with ESC-PTP of 5%-15%, ones with RF-CL ≥15% are classified into high risk group and ones with RF-CL <15% are classified into low risk group. CCTA should be referred for a subject in high risk group. Subjects determined to be at low risk will be referred to optimal medication treatment with no immediate CCTA.

According to NICE strategy, subjects with nonanginal chest pain and normal ECG are classified into low risk group and ones with typical and atypical angina or nonanginal chest pain with abnormal ECG are classified into high risk group. CCTA should be referred for a subject in high risk group. Subjects determined to be at low risk will be referred to optimal medication treatment with no immediate CCTA.

ESC-PTP is calculated using age, sex and type of chest pain according to 2019 ESC guideline for the diagnosis and management of CCS and RF-CL is calculated using age, sex, type of chest pain, hypertension, dyslipidemia, diabetes, smoking and family history of CAD based on the publication of Winther et al., respectively. According to ESC strategy, subjects with ESC-PTP ≤5% are classified into low risk group and ones with ESC-PTP ≥15% are classified into high risk group. For subjects with ESC-PTP of 5%-15%, ones with RF-CL ≥15% are classified into high risk group and ones with RF-CL <15% are classified into low risk group. CCTA should be referred for a subject in high risk group. Subjects determined to be at low risk will be referred to optimal medication treatment with no immediate CCTA.

For subjects assigned to NICE strategy, ones with nonanginal chest pain and normal ECG were classified into low risk group and ones with typical and atypical angina or nonanginal chest pain with abnormal ECG were classified into high risk group. Subjects determined to be at low risk will be referred to optimal medication treatment with no immediate CCTA.

The summary of nonobstructive CAD, no sign of CAD and nondiagnostic result detected by CCTA according to each strategy

Myocardial infarction was defined and classified as spontaneous or coronary procedure-related MI according to the Fourth Universal Definition of Myocardial Infarction.

Inclusion criteria SCP or equivalenta suggestive of CCS and clinically stability No history of CAD (prior myocardial infarction, CR or any CAD documented by previous CIT) Age ≥30 years Willing and able to provide informed consent Exclusion criteria Prior CIT within 1 year prior to randomization Clinically instability (e.g. cardiogenic shock, ACS, severe arrhythmias or NYHA III or IV heart failure) Non-sinus rhythm Concomitant participation in another clinical trial Complex structural heart disease Non-cardiac illness with life expectancy < 2 years Allergy to iodinated contrast agent Estimated glomerular filtration rate<60 ml/min/1.73m2 within 90 days Body mass index >35kg/m2 Expressing a clear preference for undergoing CIT or not Pregnancy