CCTA to Optimize the Diagnostic Yield of Invasive Angiography

Study Overview
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Brief Summary
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This study aims to reduce patient risk and costs to the healthcare system by improving the diagnostic yield of invasive coronary angiography through existing triage processes to improve risk stratification using Coronary Computed Tomographic Angiography (CCTA) as a first step in low risk patients. All low-risk patients referred for invasive coronary angiography will be potentially eligible for CCTA instead of invasive angiography as a first-line diagnostic test. All CCTAs will be read by both a level 3-trained cardiologist and a radiologist. The results of the CCTA, coupled with evidence-based management recommendations will be sent to the referring physician and an invasive angiogram will be arranged by the HIU triage, only when clearly indicated

Official Title
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Coronary Computed Tomographic Angiography to Optimize the Diagnostic Yield of Invasive Angiography in Lower Risk Patients

Conditions
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Coronary Artery Disease

Intervention / Treatment
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* Diagnostic Test: Coronary Computed Tomographic Angiography


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Non urgent outpatient referral Canadian Cardiovascular Society class I or II Indication for invasive angiogram includes: Rule out Coronary Artery Disease (CAD) and Cardiomyopathy Exclusion Criteria: Age <18 years old, Men >65 years old or women >75 years old Patient refusal to provide verbal consent for CCTA at time of triage contact or unable to provide informed consent Referring physician refusal for their eligible patients to be approached for the CarDIA study Any prior CCTA Atrial Fibrillation Creatinine > 150 mmol/L Diabetes mellitus High risk Exercise Stress Test or Functional Imaging Known severe valvular disease being considered for valve surgery Any known CAD Prior Acute Coronary Syndrome (ACS) Prior Percutaneous Coronary Intervention (PCI) or Coronary Artery Bypass Graft (CABG)

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 75 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Intervention Group<br>All low-risk patients referred for invasive coronary angiography through the Hamilton General Hospital's Heart Investigation Unit Triage will be potentially eligible to receive the intervention over a 12-month period. The intervention will include risk stratification with CCTA at HHS and NHS as an alternative to upfront invasive angiography. | Diagnostic Test: Coronary Computed Tomographic Angiography<br>* All low-risk patients referred for invasive coronary angiography will be potentially eligible to receive the intervention over a 12-month period. The intervention will include risk stratification using Coronary Computed Tomographic Angiography (CCTA) at HHS and NHS as an alternative to upfront invasive angiography. All CCTAs will be read by both a level 3-trained cardiologist and a radiologist. The results of the CCTA, coupled with evidence-based management recommendations will be sent to the referring physician and an invasive angiogram will be arranged only when indicated as per these management recommendations<br>|
| Control Group<br>Intervention sites will act as their own controls: outcomes of all eligible patients in the 24-months prior to the implementation of the intervention will be assessed from a routinely collected health administrative database. Eligible patients not undergoing CCTA (patient or physician refusal, or CCTA not available) will be captured and included in the control group as part of a sensitivity analysis during the intervention period | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Diagnostic yield of invasive angiography | Diagnostic yield is defined as the proportion of invasive angiograms that identify significant disease (≥70% stenosis) on a major coronary vessel (>2 mm) or > 50% stenosis in the left main) | Three years | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Quantitative assessment of angiograms avoided | Number of angiograms avoided due to CCTA bookings | Three years | 
| Deviation from management recommendations following CCTA | Number of angiograms performed when not recommended | Three years | 
| Protocol deviation as a surrogate for acceptability of the novel triage program | Percentage of patients and physicians refusing to undergo CCTA as a first step | Three years | 
| Costing of new strategy | Cost of risk stratification of Coronary Artery Disease in low risk patients | Three years | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Angiogram, Coronary Computed Tomographic Angiography