Visual assessment of Korotkoff sounds improves the accuracy of a validated professional automated auscultatory blood pressure monitor KOROT P3 Accurate.

Objective: A novel automated auscultatory upper-arm cuff blood pressure (BP) monitor for office use (KOROT P3 Accurate, previously InBody BPBIO480KV), which displays Korotkoff sound curves for each BP reading was recently developed. This study investigated whether the review of Korotkoff sound curves by healthcare professionals further improves the accuracy of the device by identifying unreliable BP readings.

Methods: Three observers assessed independently the morphology of Korotkoff sound curves of BP measurements obtained during an ISO 81060-2:2018 validation study, and classified them as of good, fair, or poor quality (low amplitude or sound intensity, aberrant morphology, background noise, signal artifact, auscultatory gap, irregular rhythm). The observers were blinded to the study BP measurements.

Results: Korotkoff sound curves of 255 BP readings obtained in 85 individuals were analyzed (mean age 57.3 ± 15.0 years, 53 men). Of the SBP readings 80.4/12.2/7.4% were classified as good/fair/poor, and DBP 76.9/12.2/10.9%. Inter-observer agreement in detecting poor-quality curves was 84.7/83.1% (systolic/diastolic). Of poor-quality curves, 10.5/60.7% (systolic/diastolic) clustered in the same individuals. The validation criterion 1 [mean test-reference BP difference ≤5 ± 8 (SD) mmHg] was satisfied for readings with good (0.1 ± 4.9/0.3 ± 3.8 mmHg, systolic/diastolic) and fair-quality curves (-0.4 ± 6.4/0.2 ± 5.0), but not for poor-quality ones (2.7 ± 8.8/3.6 ± 8.1). By excluding poor-quality readings (40 of 255), criterion 1 of the validation study was improved (0.2 ± 4.9/0.2 ± 3.9 versus 0.3 ± 5.5/0.6 ± 4.7 mmHg).

Conclusion: The visual assessment of Korotkoff sounds generated during automated auscultatory BP measurement by the KOROT P3 Accurate professional monitor identifies unreliable readings and further improves the device accuracy.