Development and Validation of a Risk Score for Respiratory Failure After Cardiac Surgery

Association of Preoperative Functional Status With Short-Term Major Adverse Outcomes After Cardiac Surgery

Introduction Cardiac surgery plays a crucial role in treating a wide range of cardiovascular conditions, offering life-saving interventions for patients with diseases such as coronary artery disease, heart valve disorders, and heart failure. However, these procedures are not without significant risks, including complications such as stroke, acute kidney injury, respiratory failure, and infections. It is important to not only recognize the potential complications associated with these procedures but also identify high-risk patients early in the treatment process. With the aging population and the increasing burden of comorbidities, a growing number of patients are likely to present with suboptimal functional status prior to cardiac surgery. By incorporating functional status into preoperative evaluations, healthcare providers can improve patient selection, enhance perioperative care, and improve outcomes in this high-risk patient population. Therefore, this study aims to investigate whether preoperative dependent functional status is associated with an increased risk of postoperative major adverse outcomes in patients undergoing cardiac surgery. Methods We performed a retrospective cohort analysis on adult cardiac surgery patients based on the American College of Surgeons National Surgical Quality Improvement Program (ACS NSQIP) 2011-2021 database. We compared a primary composite outcome consisting of post-surgery outcomes between independent and partially/totally dependent patients. The primary outcome was defined as experiencing any of the following adverse events: superficial incisional/deep incisional/organ space surgical site infection, death within 30 days post-operation, stroke/cerebral vascular accident (CVA), cardiac arrest requiring cardiopulmonary resuscitation (CPR), myocardial infarction, pulmonary embolism (PE), deep vein thrombosis (DVT)/thrombophlebitis, progressive renal insufficiency, ventilator use for more than 48 hours post-operation, unplanned intubation or reoperation, sepsis, septic shock, and pneumonia. Confounding variables were age, gender, race, emergency case, comorbidities, and baseline laboratory markers. We used multivariable logistic regression analysis to obtain adjusted odds ratio (OR) and 95% confidence intervals (CIs). Results Of the 42,917 patients included in the study, 30.6% were female and 69.4% were male, with 46.5% of the group being 65-79 years old. The prevalence of dependent status was 2.6%. Compared to independent patients, those who were dependent had a higher incidence of the primary outcome (35.68% vs. 20.93%), yielding a crude OR of 2.09 (95% CI 1.85-2.37). The association remained significant: OR of 1.21 (95% CI 1.04-1.41) after adjustment for age, gender, race, body mass index (BMI), emergency case, and other comorbidities such as diabetes, hypertension, heart failure, preoperative blood transfusion or sepsis, and laboratory markers. Conclusion Patients with preoperative dependent functional status were found to have a significantly greater risk of complications after cardiac surgery, even after adjusting for demographics, comorbidities, laboratory markers, and perioperative characteristics. Further investigation is needed to explore the development and clinical application of a predictive tool that includes functional status, which could help identify high-risk patients and facilitate timely interventions such as prehabilitation programs to enhance functional capacity.

A systematic review of cardiac surgery clinical prediction models that include intra-operative variables

BACKGROUND

Most cardiac surgery clinical prediction models (CPMs) are developed using pre-operative variables to predict post-operative outcomes. Some CPMs are developed with intra-operative variables, but none are widely used. The objective of this systematic review was to identify CPMs with intra-operative variables that predict short-term outcomes following adult cardiac surgery.

METHODS

Ovid MEDLINE and EMBASE databases were searched from inception to December 2022, for studies developing a CPM with at least one intra-operative variable. Data were extracted using a critical appraisal framework and bias assessment tool. Model performance was analysed using discrimination and calibration measures.

RESULTS

A total of 24 models were identified. Frequent predicted outcomes were acute kidney injury (9/24 studies) and peri-operative mortality (6/24 studies). Frequent pre-operative variables were age (18/24 studies) and creatinine/eGFR (18/24 studies). Common intra-operative variables were cardiopulmonary bypass time (16/24 studies) and transfusion (13/24 studies). Model discrimination was acceptable for all internally validated models (AUC 0.69-0.91). Calibration was poor (15/24 studies) or unreported (8/24 studies). Most CPMs were at a high or indeterminate risk of bias (23/24 models). The added value of intra-operative variables was assessed in six studies with statistically significantly improved discrimination demonstrated in two.

CONCLUSION

Weak reporting and methodological limitations may restrict wider applicability and adoption of existing CPMs that include intra-operative variables. There is some evidence that CPM discrimination is improved with the addition of intra-operative variables. Further work is required to understand the role of intra-operative CPMs in the management of cardiac surgery patients.

The early and long-term outcomes of coronary artery bypass grafting added to aortic valve replacement compared to isolated aortic valve replacement in elderly patients: a systematic review and meta-analysis

In aged population, the early and long-term outcomes of coronary revascularization (CABG) added to surgical aortic valve replacement (SAVR) compared to isolated SAVR (i-SAVR) are conflicting. To address this limitation, a meta-analysis comparing the early and late outcomes of SAVR plus CABG with i-SAVR was performed. Electronic databases from January 2000 to November 2021 were screened. Studies reporting early-term and long-term comparison between the two treatments in patients over 75 years were analyzed. The primary endpoints were in-hospital/30-day mortality and overall long-term survival. The pooled odd ratio (OR) and hazard ratio (HR) with 95% confidence interval (CI) were calculated for in-early outcome and long-term survival, respectively. Random-effect model was used in all analyses. Forty-four retrospective observational studies reporting on 74,560 patients (i-SAVR = 36,062; SAVR + CABG = 38,498) were included for comparison. The pooled analysis revealed that i-SAVR was significantly associated with lower rate of early mortality compared to SAVR plus CABG (OR = 0.70, 95% CI 0.66–0.75; p < 0.0001) and with lower incidence of postoperative acute renal failure (OR = 0.65; 95% CI 0.50–0.91; p = 0.02), need for dialysis (OR = 0.65; 95% CI 0.50–0.86; p = 0.002) and prolonged mechanical ventilation (OR = 0.57; 95% CI 0.42–0.77; p < 0.0001). Twenty-two studies reported data of long-term follow-up. No differences were reported between the two groups in long-term survival (HR = 0.95; 95% CI  0.87–1.03; p = 0.23). CABG added to SAVR is associated with worse early outcomes in terms of early mortality, postoperative acute renal failure, and prolonged mechanical ventilation. Long-term survival was comparable between the two treatments.