Combining echocardiography with carotid ultrasound parameters in predicting major adverse cardiovascular events among older individuals with coronary artery disease

Study subjects

This retrospective cohort study retrospectively analyzed coronary artery disease patients hospitalized for treatment between June 2020 and June 2021. Individuals who fulfilled the specified inclusion and exclusion criteria were chosen as participants for the study. Inclusion criteria: (1) Patients aged ≥60 years with chest pain symptoms within 24 h; (2) Patients diagnosed with acute myocardial infarction (AMI) or unstable angina (UA), both subtypes of ACS; (3) Patients with normal comprehension abilities willing to participate in follow-up after discharge. Exclusion criteria: (1) Individuals lacking complete clinical information; (2) Lost-to-follow-up patients (five cases); (3) Patients transferred to another hospital for treatment after diagnosis; (4) Patients with chest pain caused by other reasons such as trauma, generalized pain, rheumatic diseases; (5) Patients with comorbid immune, hematological diseases, hepatitis, pulmonary infections, psychiatric disorders, malignant tumors; (6) Patients with a history of previous PCI or coronary artery bypass grafting (CABG); (7) Patients with pre-existing heart failure; (8) Patients with a history of previous stroke.

This study was approved by Yantai Yuhuangding Hospital’s ethics committee. Given the retrospective nature of the study and the use of anonymized and de-identified data, the ethics committee waived the requirement for patient informed consent.

Ultrasonic methods

Follow up

Following their discharge, patients were monitored every two months through phone calls and routine outpatient visits. The follow-up period extended to three years to observe the incidence of major adverse cardiovascular events (MACE) during this timeframe. In this research, MACE was defined to include non-fatal myocardial infarction, unstable angina pectoris, arrhythmia, heart failure, stroke and all-cause mortality that occurred throughout the follow-up interval. Based on whether MACE events took place, participants were categorized into a non-MACE group (n = 84) and a MACE group (n = 54). Additionally, a separate validation cohort of 141 patients was established, which was also divided into a non-MACE group (n = 90) and a MACE group (n = 51). Patients in this validation cohort were selected based on the same inclusion and exclusion criteria as those in the primary cohort. All patients in the validation cohort also underwent the same standardized ultrasound procedures and follow-up protocols as described above. By employing a separate validation cohort, we aimed to ensure that our findings are robust and can be generalized to other patient populations. All patients included in this study cooperated with the follow-up, and their relevant data were complete. There was no missing data in this study.

Statistical analysis

The statistical analysis was conducted utilizing SPSS version 26.0 (IBM Corp., Armonk, NY, USA). Continuous data that followed a normal distribution were reported as mean ± standard deviation and assessed between groups using the independent samples t-test. Categorical variables were represented as n (%) and analyzed for differences between groups via the chi-square (χ²) test. A P-value of less than 0.05 was deemed statistically significant. To evaluate the relationship between MACE and ultrasound parameters, Spearman correlation analysis was employed. Variables demonstrating significant differences in both differential and correlation assessments were factored in as covariates in the logistic regression analysis. Additionally, the area under the receiver operating characteristic (ROC) curve (AUC) was utilized to evaluate the predictive capability of ultrasound parameters concerning MACE.

Potential confounding factors such as age, gender, BMI, smoking history, alcohol consumption, type of chest pain, medication use, complication and lesion vessel numbers were identified a priori. To adjust for these confounders, we used multivariate logistic regression models. Each confounder was included in the model as a covariate, and their effects on the outcome were controlled for during the analysis. ROC curves were constructed to evaluate the predictive performance of our model. The optimal cut-off point for predicting MACE was determined using the Youden Index, which maximizes the sum of sensitivity and specificity. The cut-off point was chosen based on the highest Youden Index value, ensuring a balance between sensitivity and specificity.

MACE situation

This study ultimately included 138 coronary artery disease patients who met the inclusion criteria. The 3-year follow-up results after discharge showed that out of the 138 patients, 54 (39.13%) experienced MACE, including 18 all-cause deaths (13.04%), 14 non-fatal myocardial infarctions (10.14%), nine cases of unstable angina pectoris (6.52%), seven cases of arrhythmia (5.07%), four cases of heart failure (2.90%), and two cases of stroke (1.45%) (Table 1). Based on different prognoses during the follow-up period, patients were divided into a non-MACE group (n = 84, 60.87%) and a MACE group (n = 54, 39.13%).

Comparison of basic information between the two groups

Table 2 presents the baseline characteristics of both patient groups. The findings indicate that there are no statistically significant differences in the baseline information between these groups (P > 0.05) (Table 2), suggesting that demographic and disease-related characteristics at baseline do not substantially influence the occurrence of MACE.

Comparison of echocardiography related indicators between the two groups

An analysis of the echocardiography parameters between the two groups revealed that the MACE group exhibited substantially elevated LVEDD and notably reduced values for LVEF and A compared to the non-MACE group (P < 0.05) (Table 3). Conversely, no significant differences were observed in LVPWT, IVST, LVESD, LAD, E-value, or the E/A ratio between the two groups (P > 0.05).

Comparison of carotid artery ultrasound related indicators between the two groups

When evaluating the carotid ultrasound parameters across the two groups, it was observed that the MACE group presented significantly elevated values for IMT and Crouse score in comparison to the non-MACE group (P < 0.05) (Table 4). In contrast, no significant differences were detected in Vs, Vd, or RI between the two groups (P > 0.05).

Multivariate logistic analysis of MACE occurrence in elderly patients with coronary artery disease

Using the occurrence of MACE as the dependent variable (coded as occurrence = 1, non-occurrence = 0), a multivariate logistic regression analysis was conducted with the echocardiography parameters (LVEDD, LVEF, and A value) and carotid ultrasound parameters (IMT and Crouse score, all considered as actual measurement values) as independent variables. The analysis revealed that LVEDD, IMT, and Crouse score were identified as risk factors for MACE in elderly individuals with coronary artery disease (OR > 1), whereas LVEF and A value were found to be protective factors against the occurrence of MACE (OR < 1) (Table 5).

Predictive value of combining echocardiography with carotid ultrasound for MACE in elderly patients with coronary artery disease

To evaluate the predictive performance of various parameters for MACE in elderly patients with coronary artery disease, we conducted ROC analysis. The optimal cut-off points were determined using the Youden index, which maximizes the sum of sensitivity and specificity (Table 6). In this study, the optimal thresholds of various parameters and their Youden indices were as follows: LVEDD (62.025 mm, Youden index 0.269), LVEF (51.635%, Youden index 0.316), A value (49.8 cm/s, Youden index 0.249), IMT (1.585 mm, Youden index 0.276), and Crouse score (0.825, Youden index 0.221). Although these parameters showed some predictive value, they did not perform notably when used individually. Future research should consider combining multiple parameters or developing composite scores to improve the accuracy of MACE prediction.

The area under the ROC curve for the combined prediction of MACE using LVEDD, LVEF, A-value, IMT, and Crouse score was 0.755 (Fig. 1), indicating good predictive value for MACE in elderly patients with coronary artery disease when combining echocardiography with carotid ultrasound.

General information (validation set)

In the validation set, 90 patients did not experience MACE, while 51 patients did. There were no significant differences in baseline information between the two groups (P > 0.05) (Table 7), suggesting that other factors may have influenced the occurrence of MACE.

Predictive indicators (validation set)

In the validation set, echocardiography parameters and carotid ultrasound parameters also showed significant differences. Among them, the MACE group had significantly higher LVEDD, IMT, and Crouse score and significantly lower LVEF and A-value compared to the non-MACE group (P < 0.05) (Table 8). This indicates that these indicators have a significant impact on the occurrence of MACE.

Joint model (validation set)

A combined predictive model for MACE was constructed using echocardiography parameters and carotid ultrasound parameters. The results showed that the AUC of the combined model in the validation set was 0.754 (Fig. 2), indicating good predictive value for the occurrence of MACE using the combination of echocardiography and carotid ultrasound parameters.