Characteristics and long-term mortality of patients with ST-elevation or non-ST-elevation myocardial infarction after orthopaedic surgery

Risk factors and prognosis of postoperative acute myocardial infarction in elderly hip fracture patients combined with coronary heart disease

INTRODUCTION

This article mainly studies the risk factors for postoperative acute myocardial infarction (AMI) in elderly hip fracture patients combined with coronary heart disease (CHD), constructs a prediction model, and evaluates the prognosis of all the patients.

METHODS

This article retrospectively collected elderly patients with hip fracture and CHD who underwent hip fracture surgery at the Third Hospital of Hebei Medical University from January 2019 to December 2021. Demographic data, laboratory indicators, and imaging examination results were collected from the medical case system. The risk factors of postoperative AMI were determined by univariate and multivariate logistic regression, and a nomogram prediction model was established. The ROC curve, calibration curve and DCA decision curve were plotted by R language software. The patients in the training set were followed up for 2 years to evaluate their survival situation.

RESULTS

1094 eligible patients were divided into a training set (n = 824 from January 1, 2019 to September 31, 2021) and a validation set (n = 270 from October 1, 2021 to December 31, 2022). In the training set, women accounted for 58.6%; The average age of the patients was 79.45 years old; The main type of fracture was intertrochanteric fracture. There were 64.7% patients taken B receptor blockers; A total of 166 (20.1%) patients underwent percutaneous coronary intervention (PCI); Hypertension accounted for 55.5%; 520 (63.1%) patients had a preoperative waiting time greater than 3 days; The average hemoglobin value upon admission was 101.36 g/L; The average intraoperative bleeding volume was 212.42 ml; The average surgical time was 2.5 ± 0.3 h; Reginal anesthesia accounted for 29.7%; 63 (68.5%) AMI patients had no obvious clinical symptoms; 68 (73.9%) AMI patients did not show ST-segment elevation in ECG; The risk factors of postoperative AMI were age, hemoglobin at admission, diabetes, chronic kidney disease, intraoperative bleeding, and reginal anesthesia. The AUC of the nomogram prediction model was 0.729. The AUC in the validation set was 0.783. Survival analysis showed a significant statistical difference in 2-year mortality between patients with AMI and without AMI, among all the patients with AMI, patients with ECG ST-segment elevation has higher mortality than patients without ECG ST-segment elevation.

CONCLUSION

Our research results found that the incidence of postoperative AMI in elderly patients with hip fractures and CHD was 11.1%. Age, diabetes, hemoglobin at admission, regional anesthesia, chronic kidney disease, and intraoperative bleeding are risk factors. The AUC of the nomogram in training set is 0.729. The 2-year mortality rate of the patients with AMI is higher than that of patients without AMI.

Characteristics of Preoperative Acute Myocardial Infarction in Elderly Hip Fracture Patients and Construction of a Clinical Prediction Model: A Retrospective Cohort Study

BACKGROUND

The prognosis of elderly patients with acute myocardial infarction (AMI) is poor, and this study aimed to investigate the characteristics and predictors of preoperative AMI in elderly hip fracture patients and to propose a valid clinical prediction model.

METHODS

We collected clinical data of older hip fracture patients from January 2019 to December 2020. The data collected include demographic and clinical characteristics, underlying diseases and laboratory results. In AMI patients, we further collected type of myocardial infarctions, clinical symptoms, electrocardiogram (ECG), Killip class and diagnosis method. The prediction model was constructed by using Least absolute shrinkage and selection operator (LASSO) regression and multivariate logistic regression analyses. In addition, the constructed prediction model was transformed into a nomogram. The performance of the model was evaluated using the area under receiver operating characteristic curve (AUC), calibration curve, and decision curve analysis (DCA). Bootstrapping was used for validation.

RESULTS

There are 40 (4.2%) cases developed AMI in all 958 patients. There were 685 (71.5%) female patients and 273 (28.5%) male patients. Among 40 AMI patients, 38 (95.0%) had Type 2 myocardial infarction (T2MI) and 2 (5.0%) had Type 1 myocardial infarction (T1MI). The majority of these ECG were ST segment depression (57.5%). Most elderly AMI patients (67.5%) presented asymptomatic. Predictors for preoperative AMI were higher age (OR 2.386, 95% CI 1.126-5.057), diabetes (OR 5.863, 95% CI 2.851-12.058), Hb≤100 g/L (OR 3.976, 95% CI 1.478-10.695), CRP≥40 mg/L (OR 6.998, 95% CI 2.875-17.033), and ALB≤35 g/L (OR 2.166, 95% CI 1.049-4.471). Good discrimination and calibration effect of the model was showed. Interval validation could still achieve the C-index value of 0.771. DCA demonstrated this nomogram has good clinical utility.

CONCLUSION

This model has a good predictive effect on preoperative AMI in elderly patients with hip fracture, which can help to better plan clinical evaluation.