Coronary Artery Disease (CAD)
Conditions
Keywords
Coronary Heart Disease, Coronary Angiography, Percutaneous Coronary Intervention, Evidence-Based Practice, Shared Decision Making, Health Care Quality Assurance, Coronary Artery Disease (CAD), computed tomography, stepped-wedge trial, health services research
Brief summary
In Germany, coronary CT offers an accurate and less burdensome alternative to cardiac catheterisation for evaluating suspected coronary artery disease, but it is still underused. The IMPRO stepped-wedge trial tests a new, nationwide care model (NVF) in 16 regions to improve guideline-based intersectoral implementation of coronary CT and assess its impact on cardiovascular outcomes and healthcare costs. If effective, the model of care (NVF) could be adopted across Germany to enhance care quality while reducing unnecessary procedures and expenses.
Detailed description
In Germany, more than 700,000 patients with chest pain undergo cardiac catheterisation each year. The most common reason is suspected coronary artery disease-the leading cause of death worldwide. Proportionally, more cardiac catheterizations are performed in Germany than in any other country. Coronary computed tomography (coronary CT) is available as an alternative diagnostic method to cardiac catheterization. The advantages of coronary CT include a lower complication rate, greater accuracy in detecting deposits in the coronary arteries, reduced burden for patients, and less procedural effort. The aim of the partners in the IMPRO project is to optimize the implementation of coronary CT in routine clinical care following the resolution of the Federal Joint Committee on January 18, 2024, while at the same time avoiding overuse. For this purpose, a new model of care will be tested in 16 different regions across 12 federal states in Germany. This model is intended to improve primary and cross-sectoral care for patients with suspected coronary artery disease. The primary goal of the nationwide study is to determine whether the new model of care helps reduce cardiovascular events, such as heart attacks and strokes, in patients with suspected coronary artery disease. The researchers will also analyze how patients respond to this type of treatment and whether it leads to cost savings. The project is funded for 39 months with a total of approximately 9.3 million euros. If successful, the new model of care could be implemented nationwide to improve the treatment of patients with suspected coronary artery disease and to avoid unnecessary costs for the healthcare system.
Interventions
BEHAVIORALIMPRO - Cross-Sectoral Care Model for Coronary Diagnostics
The intervention consists of structural and procedural components designed to improve cross-sectoral coordination in the diagnostic work-up of patients with suspected coronary artery disease (CAD). It builds upon the 2024 National Disease Management Guideline (NVL KHK 2024) and comprises three main components: (1) evidence-based initial assessment and indication for imaging diagnostics, (2) shared decision-making between primary care physicians, radiologists, and patients, and (3) quality-assured CT imaging and structured reporting in certified centres. Participating sites receive structured training, feedback, and centralized quality monitoring.
Sponsors
Philipps University Marburg
Gemeinsamer Bundesausschuss (GBA)
Study design
Allocation
RANDOMIZED
Intervention model
SEQUENTIAL
Primary purpose
DIAGNOSTIC
Masking
SINGLE (Outcomes Assessor)
Masking description
Due to the nature of the stepped-wedge trial health services intervention, participants and care providers are not blinded. Primary outcome events (MACE) are adjudicated by an independent, blinded Clinical Events Committee (CEC) based on anonymised documentation
Intervention model description
The study uses a stepped-wedge trial design in which clusters sequentially transition from a control phase to an intervention phase over a predefined period. The timing of each transition is randomised. Sixteen regional clusters in Germany, each comprising primary care networks and certified radiology departments, are allocated to four sequences. At each step, four clusters transition from control to intervention, until all clusters have implemented the intervention.
Eligibility
Sex/Gender
ALL
Age
30 Years to No maximum
Healthy volunteers
No
Inclusion criteria
* Age ≥30 years * Suspected CAD with stable chest pain * Ability to give informed consent
Exclusion criteria
* Known or previously treated (with PCI or CABG) obstructive CAD (defined as at least one coronary diameter stenosis ≥50%) * Acute coronary syndrome * Negative invasive coronary angiography or coronary CT within the last 5 years * Already enrolled in the study * Not covered by statutory health insurance * Unable to give consent
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Major Adverse Cardiovascular Events (MACE) | From enrolment to 12 months for primary MACE analysis in the G-BA-funded IMPRO trial; extended follow-up to 5 years for MACE (cardiovascular death, myocardial infarction, stroke) excluding procedure-related complications; data at 3, 12 months and 5 years | Composite endpoint: Major Adverse Cardiovascular Events (MACE) including cardiovascular death, myocardial infarction, stroke, and procedure-related complications from diagnostic testing and subsequent management/therapy in the two randomization groups. Procedure-related complications (major and minor) are defined in the subsequent outcome measure and include events occurring during or within 48 hours after CT or ICA or related tests or revascularization procedures. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Prospective Primary Safety Endpoint: Procedure-related Complications | 3 months and 12 months | Rate of procedure-related complications by diagnostic imaging modality and by interventional/surgical treatments (PCI, CABG). Includes major and minor complications. Major complications: events occurring during or within 48 hours after CT or ICA or related tests or revascularization procedures, including death, nonfatal myocardial infarction, nonfatal stroke, complications prolonging hospitalization ≥24 hours, coronary/aortic dissection, cardiogenic shock, cardiac tamponade, retroperitoneal bleeding, cardiac arrhythmia (ventricular tachycardia/fibrillation), or cardiac arrest. Minor complications: events occurring during or within 48 hours after CT or ICA or related tests or revascularization procedures not meeting major criteria, including hematoma or secondary bleeding at the puncture site, bradycardia, angina pectoris without myocardial infarction, allergic reaction to contrast media, hypotension requiring treatment, infection, thrombosis, or arteriovenous fistula. |
| Indication quality | From enrollment to 12 months (with follow-up data collection at baseline, 3 months, 12 months) | 1\) Agreement of the diagnostic decision with the pre-test probability (PTP, below 15%, 15-50%, above 50% criterion) with the National Health Services guidelines for suspected coronary artery disease and the statistical distribution of PTP values across the scale (NVL KHK 2024), measured using the updated DISCHARGE PTP calculator in the two randomisation groups, 2) Agreement of the mean pre-test probability with the prevalence of obstructive coronary artery disease (CAD) defined as at least one at least 50% coronary artery diameter stenosis on coronary computed tomography angiography (CTA) and/or invasive coronary angiography (ICA) in the two randomisation groups. |
| Functional test rates | From enrollment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years) | Rate of functional tests performed during the follow-up period (stress electrocardiography (ECG), cardiac stress magnetic resonance imaging (MRI), stress echocardiography, stress myocardial perfusion single-photon emission CT (SPECT), myocardial stress perfusion positron emission tomography (PET)) in the two randomisation groups. |
| Revascularization rates | From enrollment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years) | Rate of coronary artery revascularisations (percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG)) performed during the follow-up period in the two randomisation groups. |
| Coronary CT angiography (CTA) rates | From enrollment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years) | Rate of coronary CT performed during the follow-up period in the two randomisation groups. |
| Invasive coronary angiography (ICA) rates | From enrollment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years) | Rate of ICA procedures performed during the follow-up period in the two randomisation groups. |
| Invasive coronary angiography (ICA) results | From enrolment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years) | Rate of diagnostic findings on the ICA procedures performed in the two randomisation groups (obstructive or non-obstructive CAD or no signs of CAD) to assess the yield of ICA defined as the proportion of ICAs performed in both randomisation groups demonstrating obstructive CAD. |
| Coronary CT angiography (CTA) results | From enrolment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years) | Rate of diagnostic findings on the CTA procedures performed in the two randomisation groups (obstructive or non-obstructive CAD or no signs of CAD) to assess the yield of CTA defined as the proportion of CTAs performed in both randomisation groups demonstrating obstructive CAD. |
| Hospitalization due to chest pain | From enrollment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years) | Rate of hospitalisations due to chest pain during the follow-up period in the two randomisation groups. |
| Emergency department visits due to chest pain | From enrollment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years) | Rate of emergency department visits due to chest pain during the follow-up period in the two randomisation groups. |
| Assessability of coronary CTs | From enrollment to 12 months (with follow-up data collection at 3 months, 12 months) | Proportion of non-diagnostic coronary CTs in the two randomisation groups. |
| Radiation exposure | From enrollment to 12 months and 5 years (with follow-up data collection at 3 months, 12 months and 5 years) | Estimated radiation exposure of cardiac imaging tests including coronary CT, ICA, SPECT, and PET in the two randomisation groups in millisieverts (mSv). |
| Quality of life questionnaire | From enrollment to 3 months, 12 months and 5 years (with follow-up data collection at baseline 3 months, 12 months and 5 years) | EQ-5D-5L: validated questionnaire with five dimensions (mobility, self-care, usual activities, pain/discomfort and anxiety/depression) and 5 levels (no problems, slight problems, moderate problems, severe problems and extreme problems) in the two randomisation groups. |
| Seattle Angina Questionnaire | From enrollment to 3 months, 12 months and 5 years (with follow-up data collection at baseline 3 months, 12 months and 5 years) | SAQ-7 questionnaire (short version): disease-specific health status instrument for coronary artery disease (CAD) with seven items from the physical limitations, angina frequency, and quality of life domains in the two randomisation groups. |
| Total medical care costs (Ct) from the statutory health insurance perspective | 3 months, 6 months | Cumulative healthcare costs that can be mapped from routine health insurance data. |
| Total medical care costs (Ct) from the perspective of society | 3 months, 12 months, 5 years | Cumulative healthcare costs that can be mapped from primary data |
| Cost-effectiveness ratio (ICER) based on routine data collected by health insurers | 3 months, 6 months | ΔCt/ΔMACE: The calculated total costs are compared with MACE (primary endpoint). The results are presented as the incremental cost-effectiveness ratio (ICER). Data sources are routine data and patient survey distributed by the health insurers. |
| Cost-effectiveness ratio (ICER) based on health care utilisation data | 3 months, 12 months, 5 years | ΔCt/ΔMACE: The calculated total costs are compared with MACE (primary endpoint) in the two randomisation groups. The results are presented as the incremental cost-effectiveness ratio (ICER). Data source is primary health care utilisation data in the two randomisation groups. |
| Cost-utility ratio (ICUR) based on routine data collected by health insurers | 3 months and 6 months | ΔCt/ΔQALYs: The calculated total costs are compared with quality of life (secondary endpoint), measured using the standardised and validated EQ-5D-5L. The results are presented as the incremental cost-utility ratio (ICUR). Data sources are routine data and patient survey distributed by health insurers. |
| Cost-utility ratio (ICUR) based on health care utilisation data | 3 months, 12 months, 5 years | ΔCt/ΔQALYs: The calculated total costs are compared with quality of life (secondary endpoint), measured using the standardised and validated EQ-5D-5L. The results are presented as the incremental cost-utility ratio (ICUR). Data sources are primary data and patient quality of life survey in the two randomisation groups. |
Countries
Germany
Contacts
CONTACTAnnika Viniol, Prof. Dr.
CONTACTMarc Dewey, Prof. Dr.
PRINCIPAL_INVESTIGATORAnnika Viniol, Prof. Dr.
Philipps-Universität Marburg, Institut für Allgemeinmedizin
Outcome results
None listed