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Danish study of Non-Invasive testing in Coronary Artery Disease (Dan-NICAD): study protocol for a randomised
Louise Nissen1, Simon Winther2,3, Christin Isaksen4
1Department of Internal Medicine, Hospital Unit West, Gl.landevej 61, 7400, Herning, Denmark. lounisse@rm.dk.
Insights
This study evaluates cardiac magnetic resonance imaging and myocardial perfusion scintigraphy as secondary tests for diagnosing coronary artery disease (CAD) after initial computed tomography angiography. The goal is to optimize diagnostic algorithms and reduce unnecessary invasive procedures.
Area of Science:
- Cardiology
- Medical Imaging
- Diagnostic Accuracy
Background:
- Coronary computed tomography angiography (CCTA) is used to rule out coronary artery disease (CAD), but often has low diagnostic specificity, especially with severe calcifications.
- Many patients referred for CCTA do not have CAD, leading to a high rate of invasive coronary angiography (ICA) or non-invasive perfusion evaluations that do not result in revascularization.
- There is a need for optimized diagnostic algorithms to reduce unnecessary invasive procedures and improve patient outcomes.
Purpose of the Study:
- To determine the diagnostic accuracy of cardiac magnetic resonance imaging (CMRI) and myocardial perfusion scintigraphy (MPS) as secondary tests following CCTA in patients with suspected obstructive CAD.
- To evaluate the diagnostic precision of an acoustic technology for coronary blood flow analysis as a potential pre-CCTA stratification tool.
- To assess if secondary perfusion imaging can safely reduce the number of ICAs that do not lead to revascularization.
Main Methods:
- The Dan-NICAD trial is a multi-center, randomized, cross-sectional study involving approximately 2,000 patients referred for CCTA due to symptoms suggestive of CAD.
- Patients undergo CCTA, with data including patient interviews, sound recordings, and blood samples collected.
- Patients with suspected obstructive CAD on CCTA are randomized to stress CMRI or stress MPS, followed by ICA with fractional flow reserve (FFR) measurements for confirmation.
Main Results:
- Diagnostic performance is evaluated using sensitivity, specificity, predictive values, likelihood ratios, and C statistics.
- Obstructive CAD is defined by FFR < 0.80 or visual assessment of high-grade stenosis (>90%).
- The study aims to provide data on the effectiveness of CMRI and MPS in guiding further diagnostic and treatment decisions.
Conclusions:
- The Dan-NICAD study is designed to assess the safety and efficacy of secondary perfusion examinations in reducing unnecessary invasive procedures after CCTA.
- Results are expected to contribute valuable knowledge towards establishing an optimal diagnostic algorithm for CAD.
- The findings may lead to improved patient stratification and more efficient use of healthcare resources in CAD diagnosis.
Background:
Coronary computed tomography angiography (CCTA) is an established method for ruling out coronary artery disease (CAD). Most patients referred for CCTA do not have CAD and only approximately 20-30 % of patients are subsequently referred to further testing by invasive coronary angiography (ICA) or non-invasive perfusion evaluation due to suspected obstructive CAD. In cases with severe calcifications, a discrepancy between CCTA and ICA often occurs, leading to the well-described, low-diagnostic specificity of CCTA. As ICA is cost consuming and involves a risk of complications, an optimized algorithm would be valuable and could decrease the number of ICAs that do not lead to revascularization. The primary objective of the Dan-NICAD study is to determine the diagnostic accuracy of cardiac magnetic resonance imaging (CMRI) and myocardial perfusion scintigraphy (MPS) as secondary tests after a primary CCTA where CAD could not be ruled out. The secondary objective includes an evaluation of the diagnostic precision of an acoustic technology that analyses the sound of coronary blood flow. It may potentially provide better stratification prior to CCTA than clinical risk stratification scores alone.
Methods/Design:
Dan-NICAD is a multi-centre, randomised, cross-sectional trial, which will include approximately 2,000 patients without known CAD, who were referred to CCTA due to a history of symptoms suggestive of CAD and a low-risk to intermediate-risk profile, as evaluated by a cardiologist. Patient interview, sound recordings, and blood samples are obtained in connection with the CCTA. All patients with suspected obstructive CAD by CCTA are randomised to either stress CMRI or stress MPS, followed by ICA with fractional flow reserve (FFR) measurements. Obstructive CAD is defined as an FFR below 0.80 or as high-grade stenosis (>90 % diameter stenosis) by visual assessment. Diagnostic performance is evaluated as sensitivity, specificity, predictive values, likelihood ratios, and C statistics. Enrolment commenced in September 2014 and is expected to be complete in May 2016.
Discussion:
Dan-NICAD is designed to assess whether a secondary perfusion examination after CCTA could safely reduce the number of ICAs where revascularization is not required. The results are expected to add knowledge about the optimal algorithm for diagnosing CAD.
Trial Registration:
Clinicaltrials.gov identifier, NCT02264717 . Registered on 26 September 2014.
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