BACKGROUND Cardiac magnetic resonance (CMR) is the gold standard for left ventricular hypertrophy (LVH) diagnosis. CMR-derived LV mass can be estimated using proprietary algorithms (eg, Inli-neVF), but their accuracy and availability may be limited.
OBJECTIVETo develop an open-source deep learning model to estimate CMR-derived LV mass.METHODS Within participants of the UK Biobank prospective cohort undergoing CMR, we trained 2 convolutional neural networks to estimate LV mass. The first (ML4H reg ) performed regression informed by manually labeled LV mass (available in 5065 individuals), while the second (ML4H seg ) performed LV segmentation informed by InlineVF (version D13A) contours. We compared ML4H reg , ML4H seg , and InlineVF against manually labeled LV mass within an independent holdout set using Pearson correlation and mean absolute error (MAE). We assessed associations between CMR-derived LVH and prevalent cardiovascular disease using logistic regression adjusted for age and sex.
RESULTSWe generated CMR-derived LV mass estimates within 38,574 individuals. Among 891 individuals in the holdout set, ML4H seg reproduced manually labeled LV mass more accurately (r 5 0.864, 95% confidence interval [CI] 0.847-0.880; MAE 10.41 g, 95% CI 9.82-10.99) than ML4H reg (r 5 0.843, 95% CI 0.823-0.861; MAE 10.51, 95% CI 9.86-11.15, P 5 .01) and InlineVF (r 5 0.795, 95% CI 0.770-0.818; MAE 14.30, 95% CI 13.46-11.01, P , .01). LVH defined using ML4H seg demonstrated the strongest associations with hypertension (odds ratio 2.76, 95% CI 2.51-3.04), atrial fibrillation (1.75, 95% CI 1.37-2.20), and heart failure (4.67, 95% CI 3.28-6.49).
CONCLUSIONS ML4Hseg is an open-source deep learning model providing automated quantification of CMR-derived LV mass. Deep learning models characterizing cardiac structure may facilitate broad cardiovascular discovery.