Photoplethysmographic Prediction of the Ankle-Brachial Pressure Index through a Machine Learning Approach

David Perpetuini,Valentina Bucciarelli,Francesco Bianco,Sergio Rinella,Antonio Maria Chiarelli,Arcangelo Merla,Vincenzo Perciavalle,Giorgio Fallica,Vincenzo Vinciguerra,Sabina Gallina,Simona Massimino,Daniela Cardone

doi:10.3390/app10062137

Abstract

Cardiovascular disease is a leading cause of death. Several markers have been proposed to predict cardiovascular morbidity. The ankle-brachial index (ABI) marker is defined as the ratio between the ankle and the arm systolic blood pressures, and it is generally assessed through sphygmomanometers. An alternative tool for cardiovascular status assessment is Photoplethysmography (PPG). PPG is a non-invasive optical technique that measures volumetric blood changes induced by pulse pressure propagation within arteries. However, PPG does not provide absolute pressure estimation, making assessment of cardiovascular status less direct. The capability of a multivariate data-driven approach to predict ABI from peculiar PPG features was investigated here. ABI was measured using a commercial instrument (Enverdis Vascular Explorer, VE-ABI), and it was then used for a General Linear Model estimation of ABI from multi-site PPG in a supervised learning framework (PPG-ABI). A Receiver Operating Characteristic (ROC) analysis allowed to investigate the capability of PPG-ABI to discriminate cardiovascular impairment as defined by VE-ABI. Findings suggested that ABI can be estimated form PPG (r = 0.79) and can identify pathological cardiovascular status (AUC = 0.85). The advantages of PPG are simplicity, speed and operator-independency, allowing extensive screening of cardiovascular status and associated cardiovascular risks.

Highlights

Cardiovascular acute events, such as infarctions and strokes, are major causes of death [1], and they often occur asymptomatically without an evident pre-existing cardiovascular disease [1]
This index is commonly used in clinical practice to support diagnosis of peripheral arterial disease in the lower limbs [5], and it is considered an indicator of generalized arteriosclerosis [6]
The procedure consists in measuring the systolic blood pressure employing a Doppler sensor and a pressure cuff

Summary

Introduction

Cardiovascular acute events, such as infarctions and strokes, are major causes of death [1], and they often occur asymptomatically without an evident pre-existing cardiovascular disease [1] Prevention of such events is challenging, and it is focused on the evaluation of markers that are indicative of asymptomatic arteriosclerosis [2]. ABI is defined as the ratio between the systolic pressures at the ankle and at the arm [3,4] This index is commonly used in clinical practice to support diagnosis of peripheral arterial disease in the lower limbs [5], and it is considered an indicator of generalized arteriosclerosis [6]. The procedure consists in measuring the systolic blood pressure employing a Doppler sensor and a pressure cuff. The same procedure is repeated for all the four measurement sites in a sequential manner [8]

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Conclusion