Echocardiographic biomarkers for cross-altitude prediction of acute mountain sickness: A prospective cohort study in young males.

BACKGROUND

Current prediction tools for acute mountain sickness (AMS) are mainly limited by single-altitude designs. This study aimed to evaluate the cross-altitude predictive value of pre-ascent echocardiography and investigate altitude-specific cardiac mechanisms.

METHODS

This prospective study assigned 238 healthy young males to 3800 m (n = 106), 4300 m (n = 60), or 4500 m (n = 72) groups. Baseline echocardiography was performed at 200 m before ascent. AMS was assessed (days 1-7) using the Lake Louise Questionnaire. Candidate predictors were selected via a multi-stage process (univariate screening followed by LASSO regression) for subsequent multivariate logistic regression.

RESULTS

AMS incidence was altitude-dependent (11.3 % at 3800 m, 16.7 % at 4300 m, 55.6 % at 4500 m; P < 0.001). Pulmonary artery diameter (PAD) was a robust, consistent predictor across all altitudes (aOR = 1.53, 95 % CI 1.21-1.93, P < 0.001). Altitude-stratified analysis identified distinct predictors: right ventricular pressure load (RVOT-PGmax, aOR = 0.21, 95 % CI 0.07-0.62, P = 0.004) and structural remodeling (RV ESAi, aOR = 1.52, 95 % CI 1.13-2.05, P = 0.006) were dominant at 3800 m, whereas right ventricular systolic function (TAPSE, aOR = 2.55, 95 % CI 1.76-3.69, P < 0.001) was the primary predictor at 4500 m. The altitude-interaction model (AUC = 0.85) outperformed the global model (AUC = 0.80; P = 0.020).

CONCLUSIONS

Pre-ascent echocardiography predicts AMS risk across altitudes, with PAD emerging as a robust, cross-altitude predictor.