Classification of Atrial Fibrillation and Acute Decompensated Heart Failure Using Smartphone Mechanocardiography: A Multilabel Learning Approach

Timely diagnosis of cardiovascular diseases (CVD) is crucial to prevent morbidity and mortality. Atrial fibrillation (AFib) and heart failure (HF) are two prevalent cardiac disorders that are associated with a high risk of morbidity and mortality, especially if they are concurrently present. Current approaches fail to screen many at-risk individuals who would benefit from preventive treatment; while others receive unnecessary interventions. An effective approach to the detection of CVDs is mechanocardiography (MCG) by which translational and rotational precordial chest movements are monitored. In this study, we collected MCG data from a study sample of 300 hospitalized cardiac patients using multidimensional built-in inertial sensors of a smartphone. Our main objective was to detect concurrent AFib and acute decompensated HF (ADHF) using smartphone MCG (or sMCG). To this end, we adopted a supervised machine learning classification using multi-label and hierarchical classification. Logistic regression, random forest, and extreme gradient boosting were used as candidate classifiers. The results of the analysis showed the area under the receiver operating characteristic curve values of 0.98 and 0.85 for AFib and ADHF, respectively. The highest percentages of positive and negative predictive values for AFib were 91.9 and 100; while for ADHF, they were 56.9 and 88.4 for the multi-label classification and 69.9 and 68.8 for the hierarchical classification, respectively. We conclude that using a single sMCG measurement, AFib can be detected accurately whereas ADHF can be detected with moderate certainty.