Predictive value of echocardiography combined with hemoglobin level for left ventricular outflow tract obstruction in hypertrophic cardiomyopathy

Objective: This study aimed to explore the ability of ultrasonic parameters combined with hemoglobin (HGB) levels to predict the subsequent development of left ventricular outflow tract obstruction (LVOTO) in patients with hypertrophic cardiomyopathy (HCM). Methods: A retrospective study of 333 consecutive HCM patients receiving standardized clinical management from July 2020 to December 2025. Based on the presence or absence of LVOTO, the enrolled subjects were sorted and categorized to the two groups: LVOTO group (n = 107) and non-LVOTO group (n = 226). In this cohort of 333 patients with hypertrophic cardiomyopathy, the analysis compared those with and without LVOTO. The baseline characteristics, laboratory test results, and echocardiographic measurements were contrasted. To screen out independent risk factors that could facilitate the onset of LVOTO among HCM patients, a multivariate logistic regression analysis was performed. In addition, researchers constructed ROC curves to assess the predictive capability of echocardiographic indices and HGB concentrations for identifying LVOTO. Results: Compared with the non-LVOTO group, the LVOTO group had significantly higher rates of arrhythmias, proportion of NYHA class III, and higher E/e', LVOT peak velocity, and proportions of mitral regurgitation (MR) ≥ grade 2 and systolic anterior motion (SAM) ≥ grade 2, while HGB, LVEF, E/A, and left ventricular volumes were significantly lower (all P < 0.05). Multivariate regression analysis showed that NYHA class III, E/e', MR ≥ grade 2, and SAM ≥ grade 2 were independent risk factors for LVOTO, while HGB and LVEF were protective factors (all P < 0.05). The combined model yielded an AUC of 0.943 (sensitivity 82.08%, specificity 81.33%) for predicting LVOTO; the simplified model (HGB + SAM ≥ grade 2) achieved an AUC of 0.884 (sensitivity 79.93%, specificity 83.80%). Conclusion: HCM patients with LVOTO exhibited notable cardiac dysfunction and diastolic abnormalities, which were accompanied by reduced HGB levels. The integration of echocardiography with HGB measurements significantly improved the discriminative ability for identifying LVOTO in this population. The simplified HGB + SAM model may serve as a practical adjunct to routine echocardiographic evaluation, which showed promising internal performance and may be useful for preliminary risk assessment rather than a replacement for comprehensive assessment.