Factors Affecting Mortality Following Cardiac Surgery in the Republic of Kazakhstan

Background

Cardiovascular diseases remain the leading cause of death worldwide. According to the World Health Organization, approximately 20 million people die from them annually (32–33% of all cases), with about 80% of deaths caused by myocardial infarction and stroke. In Kazakhstan, mortality from circulatory system diseases also ranks first and increased from 193.8 to 226.9 per 100,000 population in 2020–2021. The aim of the study is to identify factors influencing the probability of a fatal outcome following cardiac surgery.

Methods

A binary logistic regression analysis was performed on data from 344 patients who underwent surgery in the cardiac surgery department of the “Regional Cardiology Center” of the Republic of Kazakhstan in 2025. The model included the patient’s sex and age, as well as the surgeon’s experience and qualifications. The model is statistically significant (χ² = 392.44; p < 0.001); Cox–Snell R² is 68%, indicating high explanatory power.

Results

According to the regression analysis, the physician’s years of experience was a significant predictor (B = −0.810; p < 0.001; OR = 0.445; 95% CI 0.345–0.573): each additional year reduces the probability of a fatal outcome by 55.5%. Patient age was also significant (B = 0.094; p = 0.014; OR = 1.098; 95% CI 1.019–1.183), increasing the risk by 9.8% per year. The physician’s qualification category showed borderline significance (B = −1.487; p = 0.059; OR = 0.226), indicating a trend toward reduced risk. Patient gender had no significant effect (p = 0.946) and was excluded from the model.

Conclusions

The analysis showed that the probability of a fatal outcome after cardiac surgery is mainly associated with the patient’s age and the physician’s experience; the physician’s qualification category shows a possible influence, while the patient’s gender is not statistically significant.

Key messages

• Increased physician experience reduces the risk of death, whereas patient age increases the likelihood of an adverse outcome.

• The physician’s qualification category shows a tendency to reduce risk, while the patient’s gender has no significant effect on treatment outcome.