Nomogram models for predicting myocardial ischemia under high altitude exposure: a cohort study

Area of Science:

• Cardiology
• Altitude Medicine
• Predictive Modeling

Background:

• High altitude exposure is a known risk factor for myocardial ischemia and cardiovascular mortality.
• Existing research lacks predictive models for myocardial ischemia specifically under high-altitude conditions.

Purpose of the Study:

• To develop and validate nomogram models for predicting myocardial ischemia in individuals exposed to high altitude.
• To identify significant risk factors contributing to myocardial ischemia in this population.

Main Methods:

• Prospective enrollment of 2,855 healthy individuals undergoing pre-high-altitude physical examination.
• Development of two nomograms: one based on clinical features (CF) and another incorporating blood tests (CF+BT).
• Model performance evaluation using Area Under the Receiver Operating Characteristic Curve (AUC) and concordance index (C-index).

Main Results:

• The CF+BT nomogram demonstrated superior predictive performance with a C-index of 0.804 and AUC of 0.80 (training) / 0.81 (validation).
• The CF-only model had lower predictive accuracy (C-index: 0.652, AUC: 0.61).
• Key risk factors for myocardial ischemia at high altitude were identified.

Conclusions:

• Successfully established two nomogram models for predicting myocardial ischemia risk associated with high-altitude exposure.
• The nomogram incorporating clinical features and blood tests offers robust predictive capability.
• Identified risk factors can aid in targeted prevention strategies for cardiovascular events at high altitudes.