Heart murmurs in the general population: diagnostic value and prevalence from the Tromsø Study.

BACKGROUND

Heart auscultation is a widely used and cost-effective clinical tool for detecting valvular heart disease (VHD), particularly in primary care. However, existing evidence on its diagnostic accuracy is limited by small sample sizes, specialist-led studies and high-prevalence settings. Robust population-based data are lacking. This study aimed to assess the prevalence and diagnostic accuracy of heart murmurs for identifying VHD in a general adult population, using echocardiography as the reference standard.

METHODS

We conducted a diagnostic accuracy study within the Seventh Tromsø Study (2015-2016), involving 2082 participants aged ≥40 years (mean age 63 years). Heart sounds were recorded at four chest locations and independently classified by general practitioners (GPs) blinded to echocardiographic results. Murmurs were graded and categorised as systolic or diastolic. Clinically significant VHD was defined as ≥mild aortic stenosis (AS) or ≥moderate aortic regurgitation (AR) or mitral regurgitation (MR). We calculated sensitivity, specificity, predictive values and likelihood ratios for murmur detection.

RESULTS

GPs detected heart murmurs in 487 participants (23%). Significant VHD was identified in 392 participants (19%), but only 139 of them (35.5%) had an audible murmur. Systolic murmurs detected all cases of AS (sensitivity 100%, specificity 78%). Sensitivity was lower for AR (43%) and MR (29%), while specificity of distinct murmurs exceeded 94% across all VHD types. Diastolic murmurs were rare (n=9) but highly specific (>99%). Among participants with murmurs, age ≥70 years (OR 2.0, 95% CI 1.2 to 3.4), male sex (OR 3.3, 95% CI 2.0 to 5.3) and previous myocardial infarction (OR 2.3, 95% CI 1.0 to 5.2) were independently associated with VHD.

CONCLUSION

In this general adult population, heart auscultation by GPs identified murmurs in nearly one in four individuals and showed high specificity but limited sensitivity for diagnosing VHD. Auscultation remains a valuable initial screening tool-especially for AS-but should be complemented by echocardiography in older or high-risk individuals.