Likelihood reclassification by an acoustic-based score in suspected coronary artery disease.

OBJECTIVE: Validation studies of the 2019 European Society of Cardiology pretest probability model (ESC-PTP) for coronary artery disease (CAD) report that 35%-40% of patients have low pretest probability (ESC-PTP 5% to <15%). Acoustic detection of coronary stenoses could potentially improve clinical likelihood stratification. Aims were to (1) investigate the diagnostic performance of an acoustic-based CAD score and (2) study the reclassification potential of a dual likelihood strategy by the ESC-PTP and a CAD score. METHODS: Consecutive patients (n=1683) with stable angina symptoms referred for coronary CT angiography (CTA) underwent heart sound analyses by an acoustic CAD-score device. All patients with ≥50% luminal stenosis in any coronary segment at coronary CTA were referred to investigation with invasive coronary angiography (ICA) with fractional flow reserve (FFR).A predefined CAD-score cut-off ≤20 was used to rule out obstructive CAD. RESULTS: In total, 439 patients (26%) had ≥50% luminal stenosis on coronary CTA. The subsequent ICA with FFR showed obstructive CAD in 199 patients (11.8%). Using the ≤20 CAD-score cut-off for obstructive CAD rule-out, sensitivity was 85.4% (95% CI 79.7 to 90.0), specificity 40.4% (95% CI 37.9 to 42.9), positive predictive value 16.1% (95% CI 13.9 to 18.5) and negative predictive value 95.4% (95% CI 93.4 to 96.9) in all patients. Applying the cut-off in ESC-PTP 5% to <15% patients, 316 patients (48%) were down-classified to very-low likelihood. The obstructive CAD prevalence was 3.5% in this group. CONCLUSION: In a large contemporary cohort of patients with low CAD likelihood, the additional use of an acoustic rule-out device showed a clear potential to downgrade likelihood and could supplement current strategies for likelihood assessment to avoid unnecessary testing. TRIAL REGISTRATION NUMBER: NCT03481712.

Diagnostic performance of an acoustic-based system for coronary artery disease risk stratification.

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.

Single-centre cohort study of gender influence in coronary CT angiography in patients with a low to intermediate pretest probability of coronary heart disease.

BACKGROUND: In 'real-world' patient populations undergoing coronary CT angiography (CCTA), it is unclear whether a correlation exists between gender, coronary artery calcium (CAC) score and subsequent referral for invasive coronary angiography and coronary revascularisation. We therefore investigated the relationship between gender, CAC and use of subsequent invasive coronary angiography and coronary revascularisation in a cohort of patients with chest discomfort and low to intermediate pretest probability of coronary artery disease who underwent a CCTA at our diagnostic centre. METHODS: This is a cohort study that included patients examined between 2010 and 2013. Data were obtained from the Western Denmark Heart Registry. The follow-up ended 11 March 2014. RESULTS: A total of 3541 people (1621 men and 1920 women) were examined by CCTA. The rate of invasive coronary angiography during follow-up was 28.5% in men versus 18.3% in women (p<0.001). The rate of coronary revascularisation during follow-up was 11.4% in men versus 5.1% in women (p<0.001). The CAC-adjusted HR in women versus men was 0.98 (95% CI 0.85 to 1.13) for invasive coronary angiography and 0.73 (95% CI 0.57 to 0.93) for coronary revascularisation. Further adjustment for age and other risk factors did not change these estimates. CONCLUSIONS: Women had a lower CAC score than men and a corresponding lower rate of invasive coronary angiography. The risk of coronary revascularisation was modestly reduced in women, irrespective of CAC. This may reflect a gender-specific difference in coping with chest discomfort, gender-specific referral bias for CCTA, and/or a gender-specific difference in the balance between coronary calcification and obstructive coronary heart disease.