Photo Credit: Tingting Ji

Per-segment indexed apical wall thickness thresholds were a highly accurate means for detecting apical hypertrophy, according to a study published in JACC Cardiovascular Imaging. James Moon, MD, and colleagues included 4,112 healthy UK Biobank imaging substudy participants, 489 healthy volunteers, and 104 people with ApHCM, including 72 with overt and 32 with relative ApHCM. Maximum wall thickness, derived by cardiac magnetic resonance, was measured in 16 segments using a published, clinically validated machine learning algorithm. The researchers observed no clinically significant age-related difference for apical wall thickness in healthy cohorts, and sex-related differences were not clinically significant after indexing to body surface area. The upper limit of normal, which was the largest of the four apical segments measured, corresponded to a maximum apical wall thickness of 5.2 to 5.6 mm/m² in healthy participants. This threshold was abnormal in 99% of patients with overt ApHCM, 78% of patients with relative ApHCM, 3% of UK Biobank participants, and 3% of healthy volunteers.