Here is the design of a clinical trial:

Official Title: Angina in Patients Without Obstructive Coronary Disease As Revealed by CT Coronary Angiography (Cor-CTCA): an Observational Cohort Study Involving Coronary Function Tests and a Nested Randomised Trial

Included conditions:
- Angina, Stable
- Angina Pectoris, Variant
- Microvascular Angina

Study Armgroups:
- {'label': 'Intervention group (coronary function test results disclosed)', 'type': 'ACTIVE_COMPARATOR', 'description': 'Coronary function tests are measured and disclosed to the clinician for re-evaluation of the initial diagnosis and treatment as compared with initial angiography. The intervention involves measurement of FFR, CFR, IMR and RRR in a major coronary artery followed by reactivity testing using incremental doses of acetylcholine (10-4 Molar (M), 10-5 M, 10-6 M) to assess endothelial function, bolus of ACh (10-4 M; 100 micrograms) for vasospasm, followed by glyceryl trinitrate (300 micrograms). FFR will be measured in all arteries with a diameter \\>=2.5 mm and a stenosis 40% to 90% in severity. Endotypes are based on criteria for abnormal coronary vasodilator function, vasospasm and microvascular resistance. The endotypes (diagnostic strata) are: obstructive CAD, vasospastic angina, microvascular angina, mixed (ie both vasospastic and microvascular disorders), endothelial dysfunction (no angina), normal (non-cardiac). A diagnosis may be ruled-in or ruled-out based on the test results.', 'interventionNames': ['Diagnostic Test: Stratified medicine involving a diagnostic intervention']}
- {'label': 'Usual care group (coronary function results not disclosed)', 'type': 'SHAM_COMPARATOR', 'description': 'Coronary function tests are measured but not disclosed to the attending clinician or the participant. The same coronary function tests are undertaken as in the intervention group. Masking is achieved by obscuring the catheter laboratory monitors from the attending clinician and participant. The effectiveness of masking and protocol adherence is prospectively monitored.', 'interventionNames': ['Diagnostic Test: Stratified medicine involving a diagnostic intervention']}

Interventions:
- {'type': 'DIAGNOSTIC_TEST', 'name': 'Stratified medicine involving a diagnostic intervention', 'description': 'Adjunctive tests of coronary artery lesion severity (fractional flow reserve) and function at the time of invasive coronary angiography. Diagnostic groups: stable coronary syndromes in patients with obstructive coronary artery disease (mis-classified by non-invasive CTCA) or no-obstructive coronary disease including the following sub-groups (coronary artery vasospasm, microvascular spasm, impaired vasorelaxation due to (1) endothelial dysfunction and/or (2) non-endothelial dysfunction, or unaffected (normal test results).\n\nMedical management is linked to contemporary clinical guidelines for the management of patients with stable coronary artery disease (European Society of Cardiology (2013), Scottish Intercollegiate Guideline Network (SIGN), 2017).', 'armGroupLabels': ['Intervention group (coronary function test results disclosed)'], 'otherNames': ['Adjunctive tests of coronary disease severity and function (disclosed)']}
- {'type': 'DIAGNOSTIC_TEST', 'name': 'Stratified medicine involving a diagnostic intervention', 'description': 'Adjunctive tests of coronary artery lesion severity (fractional flow reserve) and function at the time of invasive coronary angiography. Diagnostic groups: stable coronary syndromes in patients with obstructive coronary artery disease (mis-classified by non-invasive CTCA) or non-obstructive coronary disease including the following sub-groups (coronary artery vasospasm, microvascular spasm, impaired vasorelaxation due to (1) endothelial dysfunction and/or (2) non-endothelial dysfunction, or unaffected (normal test results).\n\nMedical management is linked to contemporary clinical guidelines for the management of patients with stable coronary artery disease (European Society of Cardiology (2013), Scottish Intercollegiate Guideline Network (SIGN), 2017).', 'armGroupLabels': ['Usual care group (coronary function results not disclosed)'], 'otherNames': ['Adjunctive tests of coronary disease severity and function (not disclosed, sham control)']}

Primary Outcomes:
- {'measure': 'Final diagnosis', 'description': 'The between-group difference in the reclassification rate of the initial diagnosis based on CTCA vs. final diagnosis after the invasive procedure involving coronary function tests in a a major coronary artery using logistic regression, adjusted for baseline factors associated with the likelihood of reclassification of the initial diagnosis.', 'timeFrame': 'Day 1'}

Please estimate the sample size based on the assumption: 
80% power to detect a 15% difference, 90% power to detect a 20% difference, adjusted for baseline characteristics such as sex and smoking status, with allowance for missing data.
Sample size calculation and statistical analysis for the diagnostic study
          The primary analysis will be the between-group comparison of the reclassification rate using logistic regression, adjusted for baseline characteristics associated with the likelihood of reclassification of the initial diagnosis. Prespecified baseline characteristics are anticipated to include sex and smoking status. If this is not possible because of small numbers, logistic regression with fewer adjustment variables or Fisher exact test will be used as appropriate. A sample size of 115 per group will have 80% power to detect a between-group difference of 15%, or 90% power to detect a difference of 20%, in the proportion of patients whose diagnosis is reclassified. To allow for any missing data, 250 patients will be randomized (Table II). If the coronary function test results are disclosed in the usual-care group (operator preference; protocol deviation), the plan before disclosure will be recorded.Table IISample size calculations for the diagnostic studyTable IISample size calculation: change in diagnosis (% of patients)Power, %Group size, nDisclosed groupUsual-care group100.1â9094â 200.1â9045â 20590114255907525108011330109092âApproximately 0%-1% reclassification.â Calculation based on Fisher exact test.