Wondering how the CADScor®System works or how it can facilitate the diagnostic pathway? We are here to help you. Find the information you need amongst the frequently asked questions, or feel free to contact us.
The CADScor®System is intended for use as a diagnostic aid in symptomatic patients suspected of stable CAD. We suggest using the CADScor®System as a first-line non-invasive diagnostic aid to rule-out CAD in patients suspected of stable CAD, to avoid further downstream testing and invasive diagnostic procedures. A patient with a low CAD-score (≤20) is highly unlikely to have CAD. A patient with an intermediate (20 – 29) or high (≥30) CAD-score has an increased likelihood of disease and should be followed more closely or referred for further evaluation.
Contraindications for use are previous coronary artery bypass graft (CABG), previous coronary stenting, arrhythmia causing non-sinus rhythm, implanted donor heart or mechanical heart, implanted mechanical heart pump, implanted pacemaker or cardioverter defibrillator (ICD), implanted electronic equipment in the area above and around the heart, significant operation scars, fragile or compromised skin, abnormal body shape in the fourth left intercostal (IC4-L)-recording area. The CADScor®System performance has not been validated outside the indication for use or, for patients younger than 40 years of age.
Patients with heart valves are not contraindicated. In Dan-NICAD, in a low number of patients with heart valve disease, higher CAD-scores were observed. Remarkably, this was only the case when the clinical risk factors were added, and not with the acoustic score only, indicating that patients with heart valve disease are diagnosed accurately. In case the artificial sound of the heart valves disturbs correct segmentation, the device would indicate this, but this has not been reported as a major issue.
Defining CAD as obstructive above 50% diameter stenosis, the sensitivity to identify a patient with CAD is 88.7%. Specificity is 41.3%. Under these conditions the test has a NPV of 97.2% in a 10% CAD prevalence population. Data has been calculated from the CADScor® clinical database using the latest implemented CADScor®System algorithm version.
Sensitivity is the ability of a test to correctly classify an individual as “diseased”. Specificity is the ability of a test to correctly classify an individual as disease-free. Positive Predictive Value (PPV) is the percentage of patients with a positive test who have the disease. Negative Predictive Value (NPV) is the percentage of patients with a negative test who do not have the disease. Positive and NPVs are directly related to the prevalence of the disease in the population. Assuming all other factors remain constant, the PPV will increase with increasing prevalence; and NPV increases with decrease in prevalence.
No. The CADScor®System does not indicate the location of stenosis; it predicts with a very high NPV that a patient is unlikely to have CAD. However, we see a correlation of the severity of CAD and the CAD-score. The more vessels show stenosis, the higher the CAD-score.
Yes. The algorithm detects signals from all coronary arteries and the low frequency sound passes with no significant loss organs and bones.
Yes, you can use the CADScor®System in this case. High calcification is neither excluded nor do we have specific data for it. We know that the higher the CACS, the higher the CAD-score.
A total occlusion does not generate heart sounds from turbulent flow. Most patients with total occlusion do not have an isolated total occlusion but a generalized CAD. Accordingly, heart sounds generated from the ischemic heart will contribute to the CAD-score. Patients with total occlusions in our database have been diagnosed as “diseased” with a CADScor >20 in the majority of cases (96%).
No. Collateral arterial supply is the biological response to decreased blood supply to a specific area in the heart. Collateral supply may have overcome the original supply defect, and as such have decreased turbulent flow patterns and aberrant myocardial movement. We do not include specific sound features from collateral arterial supply in the CAD-score.
We do not have specific data on plaque composition. A plaque, irrespective of its nature, results in a change of coronary flow and changes the acoustic information in such a way that it can be distinguished form a healthy artery.
As the CADScor®System has a very high NPV, a CAD-score at or below 20 will effectively rule-out CAD in the patient. ACAD-score above 20 will, on the other hand, indicate that the likelihood of a CAD is increased.
The CADScor®System is approved in Europe (CE mark 2015) and has been marketed since Q2 2017.
Currently (mid 2019), the CADScor®System is used in Denmark, Sweden, Germany and Austria.
The CADScor®System is a Class IIa device. The patch is a Class I device.
In section 11 of the CADScor®System user manual.
The system will indicate if the battery is low. The battery drain is significant during qualifications. Charging it for 15 minutes is sufficient for a couple of recordings, 30 minutes for approximately 10 recordings.
Guiding the patient during the CAD-score evaluation is essential. Two parts of each recording loop exists, one in which the patient is breathing normally and one in which the patient will hold his/her breath. During the breath holding period no talking (or noisy behavior) can take place.
No. The patch contains a specific code that is registered and marks the patch as used.
The used patches can be disposed together with other standard clinical waste.
In 2015 a study from Winther et al. (Denmark), with 228 patients, led to the approval of the device with algorithm v2 Europe. The study was published in 2016 with a diagnostic performance for diagnosing >50% stenosis with 90% sensitivity and 92% NPV (prevalence 28%). Dan-NICAD (Denmark), with 1675 patients, was published in 2017 and was the basis for the evolution of algorithm v2 towards algorithm v3.1 which is performing in the commercial device. The Dan-NICAD population showed a diagnostic performance of 81% sensitivity and 96% NPV for diagnosing >50% stenosis (prevalence 9.3%).
The combined database population (prevalence 10%) performs with 88.7% sensitivity and 97% NPV. 2016 and 2017 VALIDATE (Germany) were performed to gain data outside the intended population (high-prevalence population) to contribute to the evolution of the algorithm. Currently (mid 2019), Dan-NICAD II is ongoing. The CADScor®System Algorithm v3.1 database performance is based on 2245 patients (prevalence 10%). Eight acoustic properties covering four aspects of the heart sound are assessed and subsequently combined with clinical risk factors (age, gender, Hypertension), using logistic regression into a CAD-score. Examples of the acoustic properties are the amplitude of the fourth heart sound, the characteristics of the systolic and mid-diastolic heart sound and the frequency distribution of the second heart sound. All those sounds have previously described to be predictive of the presence of CAD.
Yes, there are several clinical studies ongoing and some soon to be initiated