Acoustic heart sound analysis using the CADScorSystem yielded a negative predictive value of 90.7% (95% CI 78.4-96.3) for ruling out MI, which was inferior to serial high-sensitivity troponin.
Observational (n=167)
Does acoustic heart sound analysis (CADScorSystem) accurately rule out myocardial infarction in patients presenting to the emergency department with suspected MI?
Acoustic heart sound analysis using the CADScorSystem is not feasible for ruling out myocardial infarction in the emergency department due to low measurement success rates and diagnostic performance inferior to standard high-sensitivity troponin testing.
BACKGROUND: As only a small proportion of patients with chest pain suffers from myocardial infarction (MI), safe rule-out of MI is of immense importance. Recently an ultrasensitive microphone performing diastolic heart sound analysis (CADScorSystem) for rule-out of coronary artery disease (CAD) has emerged. In this explorational study, we aimed to evaluate the feasibility of the CADScorSystem for diagnosis of MI in the setting of a large emergency department. METHODS: Patients presenting to the emergency department with suspected MI were included. Acoustic heart sound analysis was performed in all patients and automated CAD-score values were calculated via a device-embedded algorithm, which also requires inclusion of three clinical variables: age, sex and presence of hypertension. Patients additionally received serial high-sensitive troponin T measurement measurements to assess the final diagnosis according to third Universal Definition of Myocardial Infarction applying the European Society of Cardiology 0 hour/3 hours algorithm. Diagnostic parameters for MI, considering different CAD-score cut-offs, were computed. RESULTS: Of 167 patients, CAD-scores were available in 61.1%. A total of eight patients were diagnosed with MI. At a cut-off value of <20, CAD-score had a negative predictive value (NPV) of 90.7 (78.4-96.3). The corresponding positive predictive value (PPV) was 6.8 (2.7-16.2). For the adjusted CAD-score (age, sex, hypertension), at a cut-off value of <20, NPV was 90.0 (59.6-99.5) with a PPV of 10.8 (5.3-20.6). CONCLUSION: In this explorative analysis, a transcutaneous ultrasensitive microphone for heart sound analysis resulted in a high NPV analogous to the findings in rule-out of stable CAD in elective patients yet inferior to serial high-sensitivity cardiac troponin measurements and does not seem feasible for application in an emergency setting for rule-out of MI. TRIAL REGISTRATION NUMBER: NCT02355457.
Lehmacher et al. (Wed,) conducted a observational in suspected myocardial infarction (n=167). CADScorSystem (acoustic heart sound analysis) vs. serial high-sensitive troponin T measurement was evaluated on Negative predictive value for MI at CAD-score cut-off <20 (95% CI 78.4-96.3). Acoustic heart sound analysis using the CADScorSystem yielded a negative predictive value of 90.7% (95% CI 78.4-96.3) for ruling out MI, which was inferior to serial high-sensitivity troponin.