Screening for hypertrophic cardiomyopathy in adults using ECG-derived frontal QRS-T angle

Hypertrophic cardiomyopathy (HCM) is a common inherited cardiac disorder associated with increased risk of arrhythmias and sudden cardiac death. While the spatial QRS-T angle has shown strong performance for detecting HCM retrospectively, its widespread clinical utility is limited by a need for specific equipment or dense computations. The frontal QRS-T angle can easily be derived from any 12‑lead electrocardiogram (ECG) and may offer a practical screening alternative.

We conducted a retrospective analysis of 3133 adults over the age of 30 who participated in the Heartfelt community cardiovascular screening program, including 3124 controls and 9 HCM cases. In the primary analysis, HCM was defined as septal or posterior left ventricular wall thickness ≥15 mm in the absence of hypertension. In a secondary analysis, the definition of HCM was expanded to include patients with hypertension. Frontal QRS-T angle was derived from standard 12‑lead ECGs by calculating the absolute difference between frontal plane QRS axis and the T axis. Receiver operating characteristic (ROC) curve analysis was used to assess the diagnostic performance of frontal QRS-T angle in predicting HCM. In addition, logistic regression was performed to evaluate the association between the frontal QRS-T angle and HCM.

In the primary analysis, the frontal QRS-T angle demonstrated fair discriminatory ability for HCM detection, with an area under the ROC curve (AUC) of 0.711 (95% CI 0.520-0.901). At a cutoff threshold of 44.5°, sensitivity was 67% and specificity was 86%. In the secondary ROC analysis, which included patients with underlying hypertension in the HCM group, the AUC was 0.806 (95% CI 0.676-0.935). At a threshold of 46.5°, sensitivity was 44% and specificity was 87%. In multivariate logistic regression, frontal QRS-T angle was independently associated with HCM (adjusted OR per 1° increase 1.023; 95% CI 1.008-1.039; p = 0.003).

The ECG-derived frontal QRS-T angle showed fair to good diagnostic performance as a screening tool for HCM in a healthy adult screening cohort. A higher frontal QRS-T angle was also independently associated with greater odds of HCM in a logistic regression analysis. These findings suggest that the QRS-T angle may serve as a useful, noninvasive adjunct for identifying individuals at risk for HCM in broader clinical populations. Further studies with larger and more balanced cohorts are warranted to validate these findings.