Article Text
Abstract
Objective Diagnosing coronary artery disease (CAD) continues to require substantial healthcare resources. Acoustic analysis of transcutaneous heart sounds of cardiac movement and intracoronary turbulence due to obstructive coronary disease could potentially change this. The aim of this study was thus to test the diagnostic accuracy of a new portable acoustic device for detection of CAD.
Methods We included 1675 patients consecutively with low to intermediate likelihood of CAD who had been referred for cardiac CT angiography. If significant obstruction was suspected in any coronary segment, patients were referred to invasive angiography and fractional flow reserve (FFR) assessment. Heart sound analysis was performed in all patients. A predefined acoustic CAD-score algorithm was evaluated; subsequently, we developed and validated an updated CAD-score algorithm that included both acoustic features and clinical risk factors. Low risk is indicated by a CAD-score value ≤20.
Results Haemodynamically significant CAD assessed from FFR was present in 145 (10.0%) patients. In the entire cohort, the predefined CAD-score had a sensitivity of 63% and a specificity of 44%. In total, 50% had an updated CAD-score value ≤20. At this cut-off, sensitivity was 81% (95% CI 73% to 87%), specificity 53% (95% CI 50% to 56%), positive predictive value 16% (95% CI 13% to 18%) and negative predictive value 96% (95% CI 95% to 98%) for diagnosing haemodynamically significant CAD.
Conclusion Sound-based detection of CAD enables risk stratification superior to clinical risk scores. With a negative predictive value of 96%, this new acoustic rule-out system could potentially supplement clinical assessment to guide decisions on the need for further diagnostic investigation.
Trial registration number ClinicalTrials.gov identifier NCT02264717; Results.
- cardiac imaging and diagnostics
- coronary artery disease
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Footnotes
Contributors Substantial contribution to conception and design: SW, LN, SES, NRH, HEB and MB. Collection of data: SW, LN, JSW, LDR, LLK, LHM, JKJ and LF. Analysis and interpretation of data: SW, LN, SES, JSW, BSL, JJS, EHC, HEB and MB. All authors have worked on drafting the article or revising it critically and approved the final version.
Funding The research reported here is partly financed by The Danish Heart Foundation (grant no. 15-R99-A5837-22920), The Hede Nielsen Foundation, and by an unrestricted institutional research grant from Acarix A/S.
Competing interests The current research is financed partly by Acarix A/S by an unrestricted grant. SES is a minor shareholder and part-time consultant in Acarix A/S. BSL is an industrial student at Acarix A/S. MB is part of the Acarix A/S advisory board. MB and SW received an unrestricted institutional research grant from Acarix A/S.
Ethics approval The study was approved by The Central Denmark Region Committees on Health Research Ethics and The Danish Data Protection Agency.
Provenance and peer review Not commissioned; externally peer reviewed.