Predictive factors of in-hospital mortality and of severe perioperative complications in myocardial revascularization surgery

Enhancing Prediction of Myocardial Recovery After Coronary Revascularization: Integrating Radiomics from Myocardial Contrast Echocardiography with Machine Learning

Introduction

Chronic coronary artery disease (CAD) management often relies on myocardial contrast echocardiography (MCE), yet its effectiveness is limited by subjective interpretations and difficulty in distinguishing hibernating from necrotic myocardium. This study explores the integration of machine learning (ML) with radiomics to predict functional recovery in dyskinetic myocardial segments in CAD patients undergoing revascularization, aiming to overcome these limitations.

Methods

This prospective study enrolled 55 chronic CAD patients, dividing into training (39 patients, 205 segments) and testing sets (16 patients, 68 segments). Dysfunctional myocardial segments were identified by initial wall motion scores (WMS) of ≥2 (hypokinesis or higher). Functional recovery was defined as a decrease of ≥1 grade in WMS during follow-up echocardiography. Radiomics features were extracted from dyssynergic segments in end-systolic phase MCE images across five cardiac cycles post- "flash" impulse and processed through a five-step feature selection. Four ML classifiers were trained and compared using these features and MCE parameters, to identify the optimal model for myocardial recovery prediction.

Results

Functional improvement was noted in 139 out of 273 dyskinetic segments (50.9%) following revascularization. Receiver Operating Characteristic (ROC) analysis determined that myocardial blood flow (MBF) was the most precise clinical predictor of recovery, with an area under the curve (AUC) of 0.770. Approximately 1.34 million radiomics features were extracted, with nine features identified as key predictors of myocardial recovery. The random forest (RF) model, integrating MBF values and radiomics features, demonstrated superior predictive accuracy over other ML classifiers. Validation of the RF model on the testing dataset demonstrated its effectiveness, evidenced by an AUC of 0.821, along with consistent calibration and clinical utility.

Conclusion

The integration of ML with radiomics from MCE effectively predicts myocardial recovery in CAD. The RF model, combining radiomics and MBF values, presents a non-invasive, precise approach, significantly enhancing CAD management.

Predictors of In-Hospital Mortality in Surgical Wards: A Multivariable Retrospective Cohort Analysis of 2,800,069 Hospitalizations

BACKGROUND

Identifying prognostic factors that are predictive of in-hospital mortality for patients in surgical units may help in identifying high-risk patients and developing an approach to reduce mortality. This study analyzed mortality predictors based on outcomes obtained from a national database of adult patients.

MATERIALS AND METHODS

This retrospective study design collected data obtained from the National Health Fund in Poland comprised of 2,800,069 hospitalizations of adult patients in surgical wards during one calendar year. Predictors of mortality which were analyzed included: the patient's gender and age, diagnosis-related group category assigned to the hospitalization, length of the hospitalization, hospital type, admission type, and day of admission.

RESULTS

The overall mortality rate was 0.8%, and the highest rate was seen in trauma admissions (24.5%). There was an exponential growth in mortality with respect to the patient's age, and male gender was associated with a higher risk of death. Compared to elective admissions, the mortality was 6.9-fold and 15.69-fold greater for urgent and emergency admissions (p < 0.0001), respectively. Weekend or bank holiday admissions were associated with a higher risk of death than working day admissions. The "weekend" effect appears to begin on Friday. The highest mortality was observed in less than 1 day emergency cases and with a hospital stay longer than 61 days in any type of admission.

CONCLUSION

Age, male gender, emergency admission, and admission on the weekend or a bank holiday are factors associated with greater mortality in surgical units.

Cardiovascular Health in Brazil: Trends and Perspectives

Brazil is a large country, with an evolving economy, but marked social inequalities. The population is formed by an admixture of native Brazilians, Europeans, and Africans; is predominantly urban; and faces rapid aging. Time trends related to health behaviors show a substantial reduction in smoking rates, but a rising prevalence of overweight and obesity, unhealthy eating habits, and insufficient physical activity. The high prevalence of hypertension and the increasing prevalence of diabetes mellitus are also causes for concern. Cardiovascular disease (CVD) has been the leading cause of mortality since the 1960s and has accounted for a substantial percentage of all hospitalizations. In 2011, CVD was responsible for 31% of all deaths, with ischemic heart disease (31%) and cerebrovascular diseases (30%) being the leading CVD causes. Despite an increase in the overall number of CVD deaths, the age-adjusted mortality rates for CVD declined 24% between 2000 and 2011. Health care delivered by Brazil's universal public health system, which focuses on primary prevention, has contributed to this achievement. However, the decline in age-adjusted mortality differs according to race, sex, and socioeconomic status with black individuals and lower-income populations sustaining the greatest impact of CVD, especially at younger ages. With one of the world's largest public health systems in terms of population coverage, Brazil has the means to implement actions to confront the high burden of CVD, focusing on health promotion and comprehensive care. Insufficient funding, low education levels, and social inequalities remain as the main barriers to be overcome.

Evaluation of the Society of Thoracic Surgeons score system for isolated coronary bypass graft surgery in a Brazilian population

Objective

Report the experience with the Society of Thoracic Surgeons scoring system in a Brazilian population submitted to isolated coronary artery bypass graft surgery.

Methods

Data were collected from January-2010 to December-2011, and analyzed to determine the performance of the Society of Thoracic Surgeons scoring system on the determination of postoperative mortality and morbidity, using the method of the receiver operating characteristic curve as well as the Hosmer-Lemeshow and the Chi-square goodness of fit tests. From the 1083 cardiac surgeries performed during the study period 659 represented coronary artery bypass graft procedures which are included in the present analysis. Mean age was 61.4 years and 77% were men.

Results

Goodness of fit tests have shown good calibration indexes both for mortality (X²=6.78, P=0.56) and general morbidity (X²=6.69, P=0.57). Analysis of area under the ROC-curve (AUC) demonstrated a good performance to detect the risk of death (AUC 0.76; P<0.001), renal failure (AUC 0.79; P<0.001), prolonged ventilation (AUC 0.80; P<0.001), reoperation (AUC 0.76; P<0.001) and major morbidity (AUC 0.75; P<0.001) which represents the combination of the assessed postoperative complications. STS scoring system did not present comparable results for short term hospital stay, prolonged length of hospital stay and could not be properly tested for stroke and wound infection.

Conclusion

Society of Thoracic Surgeons scoring system presented a good calibration and discrimination in our population to predict postoperative mortality and the majority of the harmful events following coronary artery bypass graft surgery. Analysis of larger samples might be needed to further validate the use of the score system in Brazilian populations.

Socioeconomic factors in the prognosis of heart failure in a Brazilian cohort

A large body of evidence supports the concept that socioeconomic factors may influence the prognosis of cardiovascular diseases. We studied the influence of socioeconomic factors in the prognosis of heart failure in 494 patients consecutively admitted to the hospital due to worsening of symptoms of heart failure in São Paulo, Brazil. The ages ranged between 15 and 90 (mean 57.5, standard deviation 14.2) years; 345 (69.8%) were men and 149 (30.2%) were women. Patients were followed-up at least for two years after hospital discharge. Two hundred and forty-one patients died due to cardiac disease during the follow-up period. Hierarchical analysis was performed with demographic and socioeconomic variables analyzed in the first level and clinical variables in the second level. At the level of the demographic and socioeconomic characteristics, care under the Public Health System (odds ratio 3.46, 95% CI 1.91 to 6.27, p<0.001) was the most important predictive factor for mortality. At the second hierarchical level, the predictive factors of mortality were Chagas' heart disease (odds ratio 3.34, 95% CI 1.90 to 5 89, p<0.001), digoxin therapy (odds ratio 1.94, 95% CI 1.09 to 3.45, p<0.025), frequency of myocardial infarctions (odds ratio 1.75, 95% CI 1.25 to 2.44, p<0.001) and arterial hypertension (odds ratio 0.47, 95% CI 0.30 to 0.73, p=0.001). Care delivered through the Public Health System may be a marker of socioeconomic conditions related with higher mortality in patients with heart failure.

Clinical Features of Elderly Patients Submitted to Coronary Artery Bypass Graft

OBJECTIVE

To describe the clinical features as well as morbidity and mortality of elderly patients submitted to coronary artery bypass graft (CABG).

DESIGN

Randomized, single-center, observational study.

METHODS

A prospective study was carried out in a tertiary referral teaching hospital (Heart Institute-Brazil). A total of 220 inpatients submitted to elective CABG were evaluated and data collected from the pre-, intra- and postoperative periods.

INSTRUMENTS

The patients were assessed according to the Geriatric Depression Scale. A diagnosis of delirium was determined according to DSM-IV criteria.

RESULTS

Of these 220 patients 64.5% were males and 35.5% females. The mean age was 71 years. The most important preoperative findings were a higher incidence of comorbidities such as hypertension (73%), diabetes mellitus (35%), dyslipidemia (27%), and previous myocardial infarction (41%). The majority of patients were found to have three or more vessels obstructed at angiography (74%). The major intraoperative findings were that a high number of the patients received more than 3 grafts (74%). A large proportion (72%) of patients needed a blood transfusion and the overall incidence of clinical complications was 33%. The overall postoperative mortality rate for this observational study was 5%. A large number of patients presented complications (56%) such as hypotension (22%), atrial fibrillation (22%), and delirium (34%).

CONCLUSIONS

Although elderly patients have a somewhat increased, however acceptable, operative mortality rate, we believe that this patient group can benefit from CABG.