OBJECTIVES: Coronary artery disease (CAD) is still the most common cause of death globally; chest pain is its the most frequent symptom. Around 90% patients showing up in German GP-offices with chest pain, suffer from other diseases. The CAD-diagnostic pathway in the German ambulatory sector is partly driven by reimbursement: statutory sick-funds do not cover coronary-CT. Ultra-sensitive phonocardiography (CADScore®, Acarix A/S) is a new Technology aiding the early rule-out of CAD. This cost comparison modeled the consequences of applying this new test to German reimbursement reality.

METHODS: We developed a decision tree model based on the 2016 German CAD-diagnostic algorithm, but only accepted methods reimbursed by statutory sick-funds in the ambulatory setting. We implemented clinical results from 1,664 symptomatic patients of the rule out device and modeled a population of typical patients with chest pain. Charges were derived from the 2018 German EBM-tariff. Probabilistic sensitivity analysis (PSA) was performed. Analytic tools were TreeAge® and MS-Excel 2016

RESULTS: The population had a mean age of 57.3 (±9.4) years, 51.5% female; 10.4% suffered from obstructive CAD. Use of phonocardiography in addition to the pretest probability (Diamond-Forrester) caused a reduction in diagnostics costs by 21.5% (386 € vs. 303 €), excluding the phonocardiography costs. Driver of the cost reduction is the high proportion of early CAD-rule-outs, which increased from 14.4% to 41%. Coronary angiography dropped from 22.0% to 16.9%. Sensitivity analyses applied to the sensitivity and specificity of the phonocardiography confirmed the cost advantage. However, false negative results increased from 2.7% to 3.4%, false positive results dropped from 12.1% to 8.3%.

CONCLUSIONS: Several trials had proven ultra-sensitive phonocardiography in CAD-diagnostic clinically successful and economically reasonable due to reduction of coronary CTs. But even without coronary-CT in the pathway, due to non-reimbursement, the economical advantage sustains. This new technology may save overall financial resources in CAD-diagnostics in Germany.