Impact of postoperative complications after cardiac surgery on long-term survival

The association of intraoperative and early postoperative events with risk of pneumonia following cardiac surgery

BACKGROUND

Pneumonia, the most common infection following cardiac surgery, is associated with major morbidity and mortality. Although prior work has identified preoperative risk factors for pneumonia, the present study evaluated the role and associated impact of intraoperative and postoperative risk factors on pneumonia after cardiac surgery.

METHODS

This observational cohort study evaluated 71,165 patients undergoing coronary and/or aortic valve surgery across 33 institutions between 2011 and 2021. Terciles of estimated pneumonia risk were compared between a validated preoperative model (Model One) and a model additionally accounting for significant intraoperative (eg, bypass duration) and postoperative (eg, extubation time) factors (Model Two). Logistic regression was used to develop and validate Model Two.

RESULTS

Postoperative pneumonia occurred in 2.62% of the patients. A total of 9 significant intraoperative and early postoperative risk factors were identified. The absolute risk of pneumonia increased across Model One terciles: low (≤1.04%), medium (1.04%-2.40%), and high (>2.40%). Model two performed well (c-statistic = 0.771). Most patients (60.1%) had no change in their preoperative versus intraoperative/postoperative risk tercile. The 19.6% of patients who increased their risk tercile with Model Two accounted for 18.6% of all pneumonia events.

CONCLUSIONS

This study identified 9 significant perioperative risk factors for pneumonia. Nearly 1 of every 5 patients moved into a higher pneumonia risk category based on their intraoperative and postoperative course. These findings may serve as the focus of future quality improvement efforts to reduce a patient's risk of postoperative pneumonia.

Re-exploration for bleeding and long-term survival after adult cardiac surgery: a meta-analysis of reconstructed time-to-event data

BACKGROUND

Postoperative bleeding requiring re-exploration is a serious complication that occurs in 2.8-4.6% of patients undergoing cardiac surgery. Re-exploration has previously been associated with a higher risk of short-term mortality. However, a comprehensive analysis of long-term outcomes after re-exploration for bleeding has not been published.

MATERIALS AND METHODS

The authors performed a systematic, three databases search to identify studies reporting long-term outcomes in patients who required re-exploration for bleeding after cardiac surgery compared to patients who did not, with at least 1-year of follow-up. Long-term survival was the primary outcome. Secondary outcomes were operative mortality, myocardial infarction, stroke, renal and respiratory complications, and hospital length of stay. Random-effects models was used. Individual patient survival data was extracted from available survival curves and reconstructed using restricted mean survival time.

RESULTS

Six studies totaling 135 456 patients were included. The average follow-up was 5.5 years. In the individual patient data, patients who required re-exploration had a significantly higher risk of death compared with patients who did not [hazard ratio (HR): 1.21; 95% CI: 1.14-1.27; P <0.001], which was confirmed by the study-level survival analysis (HR: 1.32; 95% CI: 1.12-1.56; P <0.01). Re-exploration was also associated with a higher risk of operative mortality [odds ratio (OR): 5.25, 95% CI: 4.74-5.82, P <0.0001], stroke (OR: 2.05, 95% CI: 1.72-2.43, P <0.0001), renal (OR: 4.13, 95% CI: 3.43-4.39 P <0.0001) respiratory complications (OR: 3.91, 95% CI: 2.96-5.17, P <0.0001), longer hospital length of stay (mean difference: 2.69, 95% CI: 1.68-3.69, P <0.0001), and myocardial infarction (OR: 1.85, 95% CI: 1.30-2.65, P =0.0007).

CONCLUSION

Postoperative bleeding requiring re-exploration is associated with lower long-term survival and increased risk of short-term adverse events including operative mortality, stroke, renal and respiratory complications, and longer hospital length of stay. To improve both short-term and long-term outcomes, strategies to prevent the need for re-exploration are necessary.

Perioperative Changes in Plasma Nitrite and IL-6 Levels Predict Postoperative Atrial Fibrillation (POAF) and Acute Kidney Injury (AKI) after Cardiac Surgery

Background: Postoperative atrial fibrillation (POAF) and acute kidney injury (AKI) are common yet significant complications after cardiac surgery, with incidences of up to 40% for each. Here, we assessed plasma nitrite and serum interleukin-6 (IL-6) levels before and after cardiac surgery to quantify the extent to which oxidative stress and inflammation contribute to POAF and AKI occurrence. Methods: We prospectively enrolled 206 cardiac surgical patients. Plasma nitrite and serum IL-6 levels were determined preoperatively and at 24 h, 48 h and 72 h postoperatively. The patients had continuous EKG monitoring for occurrence of POAF, while daily serum creatinine was measured for determination of stage 1 + AKI. Results: Postoperatively, 78 (38%) patients experienced AF, and 47 (23%) patients experienced stage 1 + AKI. POAF analysis: Age, ACE-inhibitor use, valve surgery and percent change in baseline plasma nitrite at 24 h postoperatively were associated with POAF in multiple logistic regression analysis. The inclusion of this new biomarker significantly improved the POAF prediction model (AUC 0.77 for clinical risk factors alone, to AUC 0.81). AKI analysis: A history of diabetes mellitus was associated with AKI in multiple logistic regression analysis, and the addition of preoperative IL-6 levels improved the prediction model for AKI occurrence (AUC 0.69 to AUC 0.74). Conclusions: We previously observed selective upregulation of NADPH oxidase isoform 4 (NOX4) in patients with AF, a critical causal role of NOX4 for AF in zebrafish and a robust inhibitory effect of nitric oxide (NO) on NOX4. Our data innovatively demonstrate that a reduction in circulating nitrite levels, likely implicative of elevated NOX4-mediated oxidative stress, independently associates with POAF and improves POAF prediction, whereas the inclusion of circulating IL-6 levels improves the prediction model for AKI. Therefore, therapeutic strategies to mitigate these pathophysiological sequalae of surgical stress may reduce the incidence of severe postoperative complications of POAF and AKI.

Postoperative Hypotension After Cardiac Surgery Is Associated With Acute Kidney Injury

OBJECTIVES

To describe the incidence of postoperative hypotension in patients undergoing cardiac surgery during the first 12 hours in the intensive care unit (ICU) and any relationship between hypotension and the development of acute kidney injury (AKI).

DESIGN

This was a retrospective, observational cohort study.

SETTING

The study took place in a single-center tertiary teaching hospital in London, UK.

PARTICIPANTS

Adult patients (n = 100) who underwent elective cardiac surgery requiring intraoperative cardiopulmonary bypass between May and November 2021 were enrolled.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

A hypotensive event was defined as mean arterial pressure <65 mmHg lasting at least 1 minute. Invasive blood pressure data was analyzed for the first 12 hours after surgery, and any association between postoperative hypotension and AKI was assessed. A total of 91% of patients experienced hypotension in the first 12 hours postprocedure. On average, patients experienced 9 hypotensive events, with events lasting an average of 5 minutes. A total of 16 patients (16%) developed at least stage 1 AKI. The average duration of hypotension was significantly higher in the AKI group (4.6 min [IQR 3.3, 8.0] v 8.1 min [IQR 5.2, 14.2], p = 0.029). Those suffering AKI had longer ICU and hospital stays.

CONCLUSIONS

This study demonstrated that hypotension in the first 12 hours following cardiac surgery is common and prolonged hypotensive events are associated with developing AKI. This emphasizes the importance of treating hypotension aggressively and highlights a target for further research and intervention.

Pain Intensity After Cardiac Surgery and its Association With Kinesiophobia: A Descriptive Study

PURPOSE

Severe pain and fear of pain may decrease physical activity and restrict movements after cardiac surgery. This study aimed to determine pain intensity after cardiac surgery and its association with kinesiophobia.

DESIGN

This was a descriptive and correlational study.

METHODS

The study was conducted with cardiac surgery patients (n = 170). The sample size was calculated by using the G*POWER 3.1 program. According to the power analysis, the sample size was calculated as 170, taking into account the dependent variable with the largest sample size (kinesiophobia) and 20% loss. The outcome measures were pain and kinesiophobia collected using the Visual Analog Scale and Tampa Kinesiophobia Scale.

FINDINGS

Married patients were at the greatest risk for kinesiophobia, higher than that for single patients (β = -3.765, β = -3.609; P < .05). Obese patients were at the greatest risk for kinesiophobia higher when compared to patients of normal weight (β = -2.907, P < .05). No statistically significant correlation was found between the pain intensity and kinesiophobia scores (P > 0.05).

CONCLUSIONS

Kinesiophobia was higher in patients after cardiac surgery. Married and obese patients were predictors of kinesiophobia; however, pain was not associated with kinesiophobia.

The impact of permanent pacemaker implantation on long-term survival after cardiac surgery: A systematic review and meta-analysis

OBJECTIVES

The long-term impact of permanent pacemaker (PPM) implantation on survival after cardiac surgery remains ill defined. We aimed to investigate the effect of PPM on survival and explore factors driving outcomes using meta-regression according to the type of surgery.

METHODS

MEDLINE, EMBASE, and the Cochrane Library Central Register of Controlled Trials were searched through October 2023 to identify studies reporting the long-term outcomes of PPM implantation. The primary outcome was all-cause mortality during follow-up. The secondary outcome was heart failure rehospitalization. The subgroup analysis and meta-regression analysis were performed according to the type of surgery.

RESULTS

A total of 28 studies met the inclusion criteria. 183,555 patients (n = 6298; PPM, n = 177,257; no PPM) were analyzed for all-cause mortality, with a weighted median follow-up of 79.7 months. PPM implantation was associated with increased risks of all-cause mortality during follow-up (hazard ratio, 1.22; confidence interval, 1.08-1.38, P < .01) and heart failure rehospitalization (hazard ratio, 1.24; confidence interval, 1.01-1.52, P = .04). Meta-regression demonstrated the adverse impact of PPM was less prominent in patients undergoing mitral or tricuspid valve surgery, whereas studies with a greater proportion with aortic valve replacement were associated with worse outcomes. Similarly, a greater proportion with atrioventricular block as an indication of PPM was associated with worse survival.

CONCLUSIONS

PPM implantation after cardiac surgery is associated with a greater risk of long-term all-cause mortality and heart failure rehospitalization. This impact is more prominent in patients undergoing aortic valve surgery or atrioventricular block as an indication than those undergoing mitral or tricuspid valve surgery.

Current RNA strategies in treating cardiovascular diseases

Cardiovascular disease (CVD) continues to impose a significant global health burden, necessitating the exploration of innovative treatment strategies. Ribonucleic acid (RNA)-based therapeutics have emerged as a promising avenue to address the complex molecular mechanisms underlying CVD pathogenesis. We present a comprehensive review of the current state of RNA therapeutics in the context of CVD, focusing on the diverse modalities that bring about transient or permanent modifications by targeting the different stages of the molecular biology central dogma. Considering the immense potential of RNA therapeutics, we have identified common gene targets that could serve as potential interventions for prevalent Mendelian CVD caused by single gene mutations, as well as acquired CVDs developed over time due to various factors. These gene targets offer opportunities to develop RNA-based treatments tailored to specific genetic and molecular pathways, presenting a novel and precise approach to address the complex pathogenesis of both types of cardiovascular conditions. Additionally, we discuss the challenges and opportunities associated with delivery strategies to achieve targeted delivery of RNA therapeutics to the cardiovascular system. This review highlights the immense potential of RNA-based interventions as a novel and precise approach to combat CVD, paving the way for future advancements in cardiovascular therapeutics.

The effect of body mass index on short-term outcomes in patients undergoing off-pump coronary artery bypass grafting surgery: a retrospective study from a single cardiovascular center

OBJECTIVE

This study is designed to investigate the impact of body mass index (BMI) on the short-term outcomes of patients undergoing off-pump coronary artery bypass graft (OPCAB) surgery.

METHODS

Data was obtained from 1006 Chinese patients who underwent isolated, primary OPCAB at a high-traffic cardiovascular center during 2020. Subjects were categorized, by BMI, into a low & normal weight (LN) group (BMI < 24 kg/m2), an overweight (OVW) group (24 ≤ BMI < 28 kg/m2), and an obese (OBS) group (BMI ≥ 28 kg/m2). Information pertaining to patients' short-term outcomes (including incidence of mortality and morbidities; duration of postoperative mechanical ventilation; length of stay in the ICU and hospital; postoperative bleeding; etc.) were extracted, and the data from each group were compared.

RESULTS

The incidences of in-hospital mortality and morbidities were similar for all three groups. The volume of fluid infusion, postoperative bleeding within 24 h and total bleeding in LN group were higher than those in the OBS group (P < 0.001). The hemoglobin level was lower in the LN group than that in the OBS group (P < 0.001). Duration of mechanical ventilation and length of stay in the ICU in the LN group were longer than those in the OBS group (P < 0.001).

CONCLUSIONS

Our results demonstrate that BMI is not significantly related with short-term outcomes in OPCAB patients. However, we suggest that OPCAB patients with low-normal BMI are more susceptible to post-operative blood loss.

Effects of RBT-1 on preconditioning response biomarkers in patients undergoing coronary artery bypass graft or heart valve surgery: a multicentre, double-blind, randomised, placebo-controlled phase 2 trial

Background

RBT-1 is a combination drug of stannic protoporfin (SnPP) and iron sucrose (FeS) that elicits a preconditioning response through activation of antioxidant, anti-inflammatory, and iron-scavenging pathways, as measured by heme oxygenase-1 (HO-1), interleukin-10 (IL-10), and ferritin, respectively. Our primary aim was to determine whether RBT-1 administered before surgery would safely and effectively elicit a preconditioning response in patients undergoing cardiac surgery.

Methods

This phase 2, double-blind, randomised, placebo-controlled, parallel-group, adaptive trial, conducted in 19 centres across the USA, Canada, and Australia, enrolled patients scheduled to undergo non-emergent coronary artery bypass graft (CABG) and/or heart valve surgery with cardiopulmonary bypass. Patients were randomised (1:1:1) to receive either a single intravenous infusion of high-dose RBT-1 (90 mg SnPP/240 mg FeS), low-dose RBT-1 (45 mg SnPP/240 mg FeS), or placebo within 24-48 h before surgery. The primary outcome was a preoperative preconditioning response, measured by a composite of plasma HO-1, IL-10, and ferritin. Safety was assessed by adverse events and laboratory parameters. Prespecified adaptive criteria permitted early stopping and enrichment. This trial is registered with ClinicalTrials.gov, NCT04564833.

Findings

Between Aug 4, 2021, and Nov 9, 2022, of 135 patients who were enrolled and randomly allocated to a study group (46 high-dose, 45 low-dose, 44 placebo), 132 (98%) were included in the primary analysis (46 high-dose, 42 low-dose, 44 placebo). At interim, the trial proceeded to full enrollment without enrichment. RBT-1 led to a greater preconditioning response than did placebo at high-dose (geometric least squares mean [GLSM] ratio, 3.58; 95% CI, 2.91-4.41; p < 0.0001) and low-dose (GLSM ratio, 2.62; 95% CI, 2.11-3.24; p < 0.0001). RBT-1 was generally well tolerated by patients. The primary drug-related adverse event was dose-dependent photosensitivity, observed in 12 (26%) of 46 patients treated with high-dose RBT-1 and in six (13%) of 45 patients treated with low-dose RBT-1 (safety population).

Interpretation

RBT-1 demonstrated a statistically significant cytoprotective preconditioning response and a manageable safety profile. Further research is needed. A phase 3 trial is planned.

Funding

Renibus Therapeutics, Inc.

The role of lung ultrasound for detecting atelectasis, consolidation, and/or pneumonia in the adult cardiac surgery population: A scoping review of the literature

OBJECTIVES

Postoperative pulmonary complications (PPCs) frequently occur after cardiac surgery and may lead to adverse patient outcomes. Traditional diagnostic tools such as auscultation or chest x-ray have inferior diagnostic accuracy compared to the gold standard (chest computed tomography). Lung ultrasound (LUS) is an emerging area of research combating these issues. However, no review has employed a formal search strategy to examine the role of LUS in identifying the specific PPCs of atelectasis, consolidation, and/or pneumonia or investigated the ability of LUS to predict these complications in this cohort. The objective of this study was to collate and present evidence for the use of LUS in the adult cardiac surgery population to specifically identify atelectasis, consolidation, and/or pneumonia.

REVIEW METHOD USED

A scoping review of the literature was completed using predefined search terms across six databases which identified 1432 articles. One additional article was included from reviewing reference lists. Six articles met the inclusion criteria, providing sufficient data for the final analysis.

DATA SOURCES

Six databases were searched: MEDLINE, Embase, CINAHL, Scopus, CENTRAL, and PEDro. This review was not registered.

REVIEW METHODS

The review followed the PRISMA Extension for Scoping Reviews.

RESULTS

Several LUS methodologies were reported across studies. Overall, LUS outperformed all other included bedside diagnostic tools, with superior diagnostic accuracy in identifying atelectasis, consolidation, and/or pneumonia. Incidences of PPCs tended to increase with each subsequent timepoint after surgery and were better identified with LUS than all other assessments. A change in diagnosis occurred at a rate of 67% with the inclusion of LUS and transthoracic echocardiography in one study. Pre-established assessment scores were improved by substituting chest x-rays with LUS scans.

CONCLUSION

The results of this scoping review support the use of LUS as a diagnostic tool after cardiac surgery; however, they also highlighted a lack of consistent methodologies used. Future research is required to determine the optimal methodology for LUS in diagnosing PPCs in this cohort and to determine whether LUS possesses the ability to predict these complications and guide proactive respiratory supports after extubation.

The impact of multimodal analgesia in coronary artery bypass graft surgery-a population-based analysis

OBJECTIVE

Multimodal pain management aims to concurrently target several pain pathways for improved treatment efficacy and recovery. We investigated associations between multimodal analgesia use and postoperative complications, length of hospital stay (LOS), and opioid consumption among patients undergoing coronary artery bypass graft surgery.

METHODS

This retrospective cohort study included 349,940 adult patients undergoing elective coronary artery bypass graft surgery (January 2006 to December 2019), from the national Premier Healthcare claims dataset. The study intervention was multimodal analgesia, defined as opioid use with the addition of nonopioid analgesic modalities. These included, nonsteroidal anti-inflammatory drugs, cyclooxygenase-2 inhibitors, paracetamol/acetaminophen, neuraxial anesthesia, steroids, gabapentin/pregabalin, and ketamine. Analgesic management was stratified into 4 categories: opioids only and multimodal analgesia with the addition of 1, 2 or ≥3 nonopioid analgesic modalities. Mixed-effects regression models measured associations between multimodal analgesia and postoperative complications, LOS, and opioid consumption measured in milligram oral morphine equivalents.

RESULTS

Multimodal analgesia was associated with a beneficial dose response pattern. With increasing nonopioid analgesic modalities added to opioid analgesia, a stepwise decrease in complication risk was consistently observed, eg, with the addition of 1, 2, or ≥3 nonopioid modalities the odds for any complication decreased by 8% (odds ratio [OR], 0.92; confidence interval [CI], 0.90-0.94), 17% (OR, 0.83; CI, 0.81-0.86), and 22% (OR, 0.78; CI 0.69-0.79), respectively. This stepwise pattern was consistent in respiratory, cardiac, and renal complications individually. Similarly, LOS decreased stepwise with added analgesic modalities.

CONCLUSIONS

These nationally representative data indicate that enhanced pain management by multiple pain pathways is associated with significant reductions in postoperative complications and shortened patient recovery.

Enhancing early functional independence following cardiac surgery: a quality improvement programme

Early mobility and activity programmes following cardiac surgery are vital for improved patient outcomes, as they accelerate the recovery of functional capacity and walking distance. We observed that only 5.3% of our patients achieved a Functional Independence Measurement (FIM) score of 80% or more by the third postoperative day (POD). Additionally, the average 6-minute walk distance achieved by the fourth POD was only 188 m. Therefore, a quality improvement (QI) project was implemented with the aim of attaining a FIM score of 80% by the third POD for more than 80% of patient underwent/undergoing cardiac surgery without complications.A model-for-improvement framework was used to drive continuous improvement. This project was implemented in February 2021. Baseline data were prospectively collected between November 2020 and January 2021 (preintervention). Outcomes were analysed using standard control chart rules to detect changes over time. Unpaired Student t-tests assessed significant differences in mean levels between two groups, (preintervention vs postintervention).χ2 tests were conducted between the two groups according to gender and patient satisfaction scores.The percentage of patients who achieved a FIM score of 80% or more by the third POD gradually increased to 91.4% 5 months following programme implementation and was sustained thereafter. The mean patient FIM score significantly improved to 81.20±3.77 (p<0.001) by the third POD. Similarly, the mean 6-minute walk distance increased to 267.90±36.10 m (p<0.001) by the fourth POD. The percentage of patients who displayed the level of confidence needed to carry out activities of daily living (ADL) and exercises independently at home increased to 89.4% (p<0.001) by the fifth POD. No adverse events associated with the mobility and activity programme were reported.This QI project demonstrated a substantial improvement in patient functional independence, walking distance and the level of confidence needed to independently carry out ADL and exercises following cardiac surgery.

Prevention of cardiac surgery-associated acute kidney injury: a systematic review and meta-analysis of non-pharmacological interventions

BACKGROUND

Cardiac surgery-associated acute kidney injury (CSA-AKI) is frequent. While two network meta-analyses assessed the impact of pharmacological interventions to prevent CSA-AKI, none focused on non-pharmacological interventions. We aim to assess the effectiveness of non-pharmacological interventions to reduce the incidence of CSA-AKI.

METHODS

We searched PubMed, Embase, Central and clinical trial registries from January 1, 2004 (first consensus definition of AKI) to July 1, 2023. Additionally, we conducted manual screening of abstracts of major anesthesia and intensive care conferences over the last 5 years and reference lists of relevant studies. We selected all randomized controlled trials (RCTs) assessing a non-pharmacological intervention to reduce the incidence of CSA-AKI, without language restriction. We excluded RCTs of heart transplantation or involving a pediatric population. The primary outcome variable was CSA-AKI. Two reviewers independently identified trials, extracted data and assessed risk of bias. Random-effects meta-analyses were conducted to calculate risk ratios (RRs) with 95% confidence intervals (CIs). We used the Grading of Recommendations Assessment, Development, and Evaluation to assess the quality of evidence.

RESULTS

We included 86 trials (25,855 patients) evaluating 10 non-pharmacological interventions to reduce the incidence of CSA-AKI. No intervention had high-quality evidence to reduce CSA-AKI. Two interventions were associated with a significant reduction in CSA-AKI incidence, with moderate quality of evidence: goal-directed perfusion (RR, 0.55 [95% CI 0.40-0.76], I2 = 0%; Phet = 0.44) and remote ischemic preconditioning (RR, 0.86 [0.78-0.95]; I2 = 23%; Phet = 0.07). Pulsatile flow during cardiopulmonary bypass was associated with a significant reduction in CSA-AKI incidence but with very low quality of evidence (RR = 0.69 [0.48; 0.99]; I2 = 53%; Phet < 0.01). We found high quality of evidence for lack of effect of restrictive transfusion strategy (RR, 1.02 [95% CI 0.92; 1.12; Phet = 0.67; I2 = 3%) and tight glycemic control (RR, 0.86 [95% CI 0.55; 1.35]; Phet = 0.25; I2 = 26%).

CONCLUSIONS

Two non-pharmacological interventions are likely to reduce CSA-AKI incidence, with moderate quality of evidence: goal-directed perfusion and remote ischemic preconditioning.

Dexmedetomidine as an anesthetic adjunct is associated with reduced complications and cardiac intensive care unit length of stay after heart valve surgery

BACKGROUND

We sought to explore the relationship between dexmedetomidine as an anesthetic adjuvant in cardiac surgery and postoperative complications and length of stay (LOS) in the cardiac intensive care unit (CICU).

METHODS

We conducted a retrospective study of patients aged 18 years and older who underwent heart valve surgery between October 2020 and June 2022. The primary endpoint of the study was major postoperative complications (cardiac arrest, atrial fibrillation, myocardial injury/infarction, heart failure) and the secondary endpoint was prolonged CICU LOS (defined as LOS > 90th percentile). Multivariate logistic regression analysis was performed for variables that were significant in the univariate analysis.

RESULTS

A total of 856 patients entered our study. The 283 patients who experienced the primary and secondary endpoints were included in the adverse outcomes group, and the remaining 573 were included in the prognostic control group. Multivariate logistic regression analysis revealed that age > 60 years (odds ratio [OR], 1.68; 95% confidence interval [CI], 1.23-2.31; p < 0.01), cardiopulmonary bypass (CPB) > 180 min (OR, 1.62; 95% CI, 1.03-2.55; p = 0.04) and postoperative mechanical ventilation time > 10 h (OR, 1.84; 95% CI, 1.35-2.52; p < 0.01) were independent risk factors for major postoperative complications; Age > 60 years (OR, 3.20; 95% CI, 1.65-6.20; p < 0.01), preoperative NYHA class 4 (OR, 4.03; 95% CI, 1.74-9.33; p < 0.01), diabetes mellitus (OR, 2.57; 95% CI, 1.22-5.41; p = 0.01), Intraoperative red blood cell (RBC) transfusion > 650 ml (OR, 2.04; 95% CI, 1.13-3.66; p = 0.02), Intraoperative bleeding > 1200 ml (OR, 2.69; 95% CI, 1.42-5.12; p < 0.01) were independent risk factors for prolonged CICU length of stay. Intraoperative use of dexmedetomidine as an anesthetic adjunct was a protective factor for major complications (odds ratio, 0.51; 95% confidence interval, 0.35-0.74; p < 0.01) and prolonged CICU stay. (odds ratio, 0.37; 95% confidence interval, 0.19-0.73; p < 0.01).

CONCLUSIONS

In patients undergoing heart valve surgery, age, duration of cardiopulmonary bypass, and duration of mechanical ventilation are associated with major postoperative complication. Age, preoperative NYHA classification 4, diabetes mellitus, intraoperative bleeding, and RBC transfusion are associated with increased CICU length of stay. Intraoperative use of dexmedetomidine may improve such clinical outcomes.

Recombinant Alpha-1-Microglobulin (RMC-035) to Prevent Acute Kidney Injury in Cardiac Surgery Patients: Phase 1b Evaluation of Safety and Pharmacokinetics

Introduction

Acute kidney injury (AKI) is a common complication in cardiac surgery patients and prevention is needed to improve clinical outcomes. Alpha-1-microglobulin (A1M) is a physiological antioxidant with strong tissue-protective and cell-protective properties that has demonstrated renoprotective effects. RMC-035, a recombinant variant of endogenous human A1M, is being developed for the prevention of AKI in cardiac surgery patients.

Methods

In this phase 1b, randomized, double-blind, and parallel group clinical study, 12 cardiac surgery patients undergoing elective, open-chest, on-pump coronary artery bypass graft and/or valve surgery with additional predisposing AKI risk factors were enrolled to receive in total 5 intravenous doses of either RMC-035 or placebo. The primary objective was to evaluate the safety and tolerability of RMC-035. The secondary objective was to evaluate its pharmacokinetic properties.

Results

RMC-035 was well tolerated. The nature and frequency of adverse events (AEs) were consistent with the expected background rates in the underlying patient population with no AEs reported as related to study drug. No clinically relevant changes were observed for vital signs or laboratory parameters except for renal biomarkers. Several established AKI urine biomarkers were reduced at 4 hours after first dose administration in the treatment group, indicating a reduced perioperative tubular cell injury following RMC-035 treatment.

Conclusion

Multiple intravenous doses of RMC-035 were well tolerated in patients undergoing cardiac surgery. Observed RMC-035 plasma exposures were safe and in the range of expected pharmacological activity. Furthermore, urine biomarkers suggest reduced perioperative kidney cell injury, warranting further investigation of RMC-035 as a potential renoprotective treatment.

Relationship Between Delirium Development and Its Causative Factors in the Intensive Care Unit After Cardiac Surgery

Background

Delirium is a clinical symptom that can have serious side effects in patients, and it develops acutely and shows reversibility. Postoperative delirium is an important neuropsychological complication after surgery that directly or indirectly affects patients.

Cardiac surgery increases the risk of delirium due to the complexity of surgical procedures, use of intraoperative and postoperative anesthetics and other pharmacologic agents, and possible postoperative complications. This study aims to determine the relationship between the development of delirium and its causative factors after cardiac surgery and its associated postoperative complications, and identify the high-relevance risk factors of postoperative delirium.

Methods

The participants comprised 730 patients who were admitted to the intensive care unit and underwent cardiac surgery. The collected data included 19 risk factors based on the patients' medical information records. As a delirium diagnostic tool, we used the Intensive Care Delirium Screening Checklist, with four or more points indicating delirium. For statistical analysis, the dependent variables were determined based on the presence or absence of delirium, while the independent variables were determined based on the risk factors of delirium. A t-test, χ² test, and logistic regression analysis were performed on risk factors between the two groups-the delirium group and no delirium group.

Results

Postoperative delirium was observed in 126 (17.3%) of 730 patients after cardiac surgery. Postoperative complications were more common in the delirium group. Independent risk factors associated with postoperative delirium were identified in 7 of the 12 factors.

Conclusion

As cardiac surgery is invasive and affects the development and severity of delirium, efforts and intervention methods are necessary to predict the risk factors for the development of delirium before surgery, and to prevent its occurrence after surgery. In the future, it is necessary to further investigate factors associated with delirium that can be directly intervened.

The Rationalisation of Intra-Operative Imaging During Cardiac Surgery: A Systematic Review

INTRODUCTION

One critical complication of cardiac surgery is cerebrovascular accidents (CVAs). Ascending aorta atherosclerosis poses a significant risk of embolisation to distal vessels and to cerebral arteries. Epi-aortic ultrasonography (EUS) is thought to offer a safe, high-quality accurate visualisation of the diseased aorta to guide the surgeon on the best surgical approach to the planned procedure and potentially improve neurological outcomes post-cardiac surgery.

METHOD

The authors conducted a comprehensive search of PubMed, Scopus and Embase. Studies that reported on epi-aortic ultrasound use in cardiac surgery were included. Major exclusion criteria were: (1) abstracts, conference presentations, editorials, literature reviews; (2) case series with <5 participants; (3) epi-aortic ultrasound in trauma or other surgeries.

RESULTS

A total of 59 studies and 48,255 patients were included in this review. Out of the studies that reported patient co-morbidities prior to cardiac surgery, 31.6% had diabetes, 59.5% had hyperlipidaemia and 66.1% had a diagnosis of hypertension. Of those that reported significant ascending aorta atherosclerosis found on EUS, this ranged from 8.3% of patients to 95.2% with a mean percentage of 37.8%. Hospital mortality ranged from 7% to 13%; four studies reported zero deaths. Long-term mortality and stroke rate varied significantly with hospital duration.

CONCLUSION

Current data have shown EUS to have superiority over manual palpation and transoesophageal echocardiography in the prevention of CVAs following cardiac surgery. Yet, EUS has not been implemented as a routine standard of care. Extensive adoption of EUS in clinical practice is warranted to aid large, randomised trials before making prospective conclusions on the efficacy of this screening method.

Impact of Post-Operative Infection after CABG on Long-Term Survival

Coronary artery bypass grafting (CABG) is one of the most common cardiac surgical procedures. It is commonly known that post-operative infection has a negative impact on the patient's short-term treatment outcomes and long-term prognosis. The aim of the present study was to assess the impact of perioperative infection on 5-year and 10-year survival in patients undergoing elective on-pump CABG surgery. The present prospective observational study was carried out between 1 July 2010 and 31 August 2012 among patients undergoing cardiac surgery at our centre. Infections were identified according to the ECDC definitions. We initially assessed the incidence of infection and its relationship with the parameters analysed. We then analysed the effect of particular parameters, including infection, on 5-year and 10-year survival after surgery. We also analysed the impact of particular types of infection on the risk of death within the period analysed. The significant risk factors for reduced survival were age (HR 1.05, CI 1.02-1.07), peripheral artery disease (HR 1.99, CI 1.28-3.10), reduced LVEF after surgery (HR 0.96, CI 0.94-0.99), post-operative myocardial infarction (HR 1.45, CI 1.05-2.02) and infection (HR 3.10, CI 2.20-4.28). We found a strong relationship between post-operative infections and 5-year and 10-year mortality in patients undergoing CABG. Pneumonia and BSI were the only types of infection that were found to have a significant impact on increased long-term mortality after CABG surgery.

[Analysis of cardiac surgeries and operative mortality at the National Cardiovascular Institute during 2022]

Objective

To describe cardiac surgeries, their approaches, and determine operative mortality according to the type of surgery and the main complications recorded within 30 days postoperatively, performed at the National Cardiovascular Institute of Peru.

Materials and methods

A descriptive study was conducted on all patients over 18 years of age who underwent cardiovascular surgery at the National Cardiovascular Institute "Carlos Alberto Peschiera Carrillo".

Results

During the year 2022, a total of 503 cardiac surgeries were performed. Of the patients undergoing surgery, 63.6% (320) were males. Isolated valvular surgery, primarily aortic or mitral valve replacement, was the most frequent surgical procedure, with 136 surgeries (27.0%). This was followed by myocardial revascularization surgery with 110 procedures (21.9%). Throughout the year, there were 23 deaths, resulting in an overall mortality rate of 4.5%. The mortality rate for elective surgeries was 2.8%, while for emergency surgeries, it was 14.3%. The most common complication was paroxysmal atrial fibrillation (14.0%), followed by surgical site infection with 52 cases (10.3%).

Conclusions

Valvular surgery, whether isolated or combined with other procedures, was the most frequently performed. The obtained mortality rate is considered acceptable for a reference center.

Hyperkalemic or Low Potassium Cardioplegia Protects against Reduction of Energy Metabolism by Oxidative Stress

Open-heart surgery is often an unavoidable option for the treatment of cardiovascular disease and prevention of cardiomyopathy. Cardiopulmonary bypass surgery requires manipulating cardiac contractile function via the perfusion of a cardioplegic solution. Procedure-associated ischemia and reperfusion (I/R) injury, a major source of oxidative stress, affects postoperative cardiac performance and long-term outcomes. Using large-scale liquid chromatography-tandem mass spectrometry (LC-MS/MS)-based metabolomics, we addressed whether cardioplegic solutions affect the baseline cellular metabolism and prevent metabolic reprogramming by oxidative stress. AC16 cardiomyocytes in culture were treated with commonly used cardioplegic solutions, High K+ (HK), Low K+ (LK), Del Nido (DN), histidine-tryptophan-ketoglutarate (HTK), or Celsior (CS). The overall metabolic profile shown by the principal component analysis (PCA) and heatmap revealed that HK or LK had a minimal impact on the baseline 78 metabolites, whereas HTK or CS significantly repressed the levels of multiple amino acids and sugars. H2O2-induced sublethal mild oxidative stress causes decreases in NAD, nicotinamide, or acetylcarnitine, but increases in glucose derivatives, including glucose 6-P, glucose 1-P, fructose, mannose, and mannose 6-P. Additional increases include metabolites of the pentose phosphate pathway, D-ribose-5-P, L-arabitol, adonitol, and xylitol. Pretreatment with HK or LK cardioplegic solution prevented most metabolic changes and increases of reactive oxygen species (ROS) elicited by H2O2. Our data indicate that HK and LK cardioplegic solutions preserve baseline metabolism and protect against metabolic reprogramming by oxidative stress.

Thoracic sarcopenia predicts clinical outcomes in patients undergoing coronary artery bypass grafting: A 6-year cohort study

BACKGROUND

The relationship between thoracic sarcopenia and clinical outcomes in patients underwent coronary artery bypass grafting (CABG) is unclear. This study aims to evaluate whether thoracic sarcopenia has a satisfactory prognostic effect on adverse outcomes after CABG.

METHODS

From December 2015 to May 2021, 338 patients who underwent isolated CABG at our institution were recruited in this study. Skeletal muscle area at T12 level acquired by chest computed tomography (CT) was normalized to assess thoracic sarcopenia. Univariate and multivariate analyses were performed to evaluate the risk factors of postoperative complications and overall survival (OS).

RESULTS

The prevalence of thoracic sarcopenia in patients underwent CABG was 13.02%. The incidence of total major complication was significantly higher in thoracic sarcopenia group (81.8% vs 61.9%, p = 0.010). Thoracic sarcopenic patients also had longer postoperative hospital stays (p = 0.047), intensive care unit (ICU) stays (p = 0.001), higher costs (p = 0.001) and readmission rates within 30 days of discharge (18.2% vs 4.4%, p = 0.001). Patients without thoracic sarcopenia showed significantly higher OS at the 2-year follow-up period (93.9% vs 72.7%, p<0.001). Multivariate analyses demonstrated that thoracic sarcopenia was significantly and independently associated with postoperative complications and long-term OS after CABG.

CONCLUSION

Thoracic sarcopenia is an effective clinical predictor of adverse postoperative complications and long-term OS in patients underwent CABG. Thoracic sarcopenia based on chest CT should be included in preoperative risk assessment of CABG.

Nosocomial Extracardiac Infections After Cardiac Surgery

Purpose of Review

Nosocomial extracardiac infections after cardiac surgery are a major public health issue affecting 3–8.2% of patients within 30–60 days following the intervention.

Recent Findings

Here, we have considered the most important postoperative infective complications that, in order of frequency, are pneumonia, surgical site infection, urinary tract infection, and bloodstream infection. The overall picture that emerges shows that they cause a greater perioperative morbidity and mortality with a longer hospitalization time and excess costs. Preventive interventions and corrective measures, diminishing the burden of nosocomial extracardiac infections, may reduce the global costs. A multidisciplinary team may assure a more appropriate management of nosocomial extracardiac infections leading to a reduction of hospitalization time and mortality rate.

Summary

The main and most current data on epidemiology, prevention, microbiology, diagnosis, and management for each one of the most important postoperative infective complications are reported. The establishment of an antimicrobial stewardship in each hospital seems to be, at the moment, the more valid strategy to counteract the challenging problems.

An unusual case of stabbing chest pain …literally: a case report

Background

Cardiac surgery is associated with a significant risk of potential postoperative complications. We describe a case of a patient with an unusual late cardiac perforation caused by a needle used to fix temporary epicardial pacing wires to the skin, which slowly migrated across subcutaneous tissues for 2 years following postoperative period.

Case summary

We report a case of middle-aged woman admitted to the cardiac intensive care unit due to suspected acute myocardial infarction. Multimodality imaging revealed the presence of an unusual intracardiac foreign body, located inside the interventricular septum and perforating towards the left atria, complicated by a small intracardiac fistula between septal coronary branches and the right ventricle. Analysis of previous examinations revealed that a needle used to fix temporary epicardial pacing wires to the skin had been left inside the patient, beneath the level of the diaphragm, after cardiac surgery in 2018. This foreign body slowly migrated across the diaphragm, towards the mediastinum, finally lodging inside the heart, after a period of 3 years. The patient was referred to cardiac surgery for foreign body retrieval.

Discussion

We describe an unusual case of cardiac perforation caused by a needle used to fix these wires to the skin, which migrated across subcutaneous tissues and finally lodged inside the basal interventricular septum and left atria. Full compliance with standardized surgical care bundles, as well as the implementation of a structured incident reporting system, is of upmost importance to prevent postoperative complications and improve surgical care.

Direct oral anticoagulants in atrial fibrillation following cardiac surgery: a systematic review and meta-analysis with trial sequential analysis

BACKGROUND

Direct oral anticoagulants (DOACs) have been increasingly used as anticoagulation therapy in the postoperative period. However, their effectiveness in post-cardiac surgical atrial fibrillation is yet to be determined.

METHODS

We conducted a meta-analysis, searching three international databases from 1 January 2003 to 26 January 2022 for studies reporting on DOACs in at least 10 adult patients (>18 yr of age) with post-cardiac surgical atrial fibrillation. The primary outcomes were major neurological events (MNEs) and bleeding; secondary outcomes were mortality, hospital and ICU length of stay, cost, and other complications from therapy. We included studies of any design, including RCTs, cohort studies with and without propensity score matching methods, and single-armed case series.

RESULTS

Twelve studies (8587 DOACs; 8315 warfarin) were included in this meta-analysis. The incidences of postoperative bleeding and MNEs with DOACs were 7.3% (95% confidence interval [CI]: 3.4-14.7%) and 2.2% (95% CI: 0.9-4.9%), respectively. The incidence of MNEs was lower in high-risk patients, including those with hypertension and higher CHA₂DS₂-VASc score, whereas patients with prior transient ischaemic attack or stroke had higher incidence of bleeding. Trial sequential analysis revealed that the cumulative Z-curve crossed the conventional boundary of benefit. Compared with warfarin, DOACs reduced the risk of bleeding (relative risk [RR] 0.74; 95% CI: 0.62-0.89; P=0.0011) and MNEs (RR 0.63; 95% CI: 0.48-0.83; P=0.0012) but not mortality (RR 1.02; 95% CI: 0.77-1.35; P=0.090).

CONCLUSIONS

DOACs reduced bleeding and MNEs in patients with post-cardiac surgical atrial fibrillation, appearing safer than warfarin in this context. However, which DOAC provides the most effective anticoagulation in this patient population needs further investigation.

CLINICAL TRIAL REGISTRATION

PROSPERO CRD42021282777.

Effect of lipid-lowering medications in patients with coronary artery bypass grafting surgery outcomes

BACKGROUND

Increased life expectancy and improved medical technology allow increasing numbers of elderly patients to undergo cardiac surgery. Elderly patients may be at greater risk of postoperative morbidity and mortality. Complications can lead to worsened quality of life, shortened life expectancy and higher healthcare costs. Reducing perioperative complications, especially severe adverse events, is key to improving outcomes in patients undergoing cardiac surgery. The objective of this study is to determine whether perioperative lipid-lowering medication use is associated with a reduced risk of complications and mortality after coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB).

METHODS

After IRB approval, we reviewed charts of 9,518 patients who underwent cardiac surgery with CPB at three medical centers between July 2001 and June 2015. The relationship between perioperative lipid-lowering treatment and postoperative outcome was investigated. 3,988 patients who underwent CABG met inclusion criteria and were analyzed. Patients were divided into lipid-lowering or non-lipid-lowering treatment groups.

RESULTS

A total of 3,988 patients were included in the final analysis. Compared to the patients without lipid-lowering medications, the patients with lipid-lowering medications had lower postoperative neurologic complications and overall mortality (P < 0.05). Propensity weighted risk-adjustment showed that lipid-lowering medication reduced in-hospital total complications (odds ratio (OR) = 0.856; 95% CI 0.781-0.938; P < 0.001); all neurologic complications (OR = 0.572; 95% CI 0.441-0.739; P < 0.001) including stroke (OR = 0.481; 95% CI 0.349-0.654; P < 0.001); in-hospital mortality (OR = 0.616; 95% CI 0.432-0.869; P = 0.006; P < 0.001); and overall mortality (OR = 0.723; 95% CI 0.634-0.824; P < 0.001). In addition, the results indicated postoperative lipid-lowering medication use was associated with improved long-term survival in this patient population.

CONCLUSIONS

Perioperative lipid-lowering medication use was associated with significantly reduced postoperative adverse events and improved overall outcome in elderly patients undergoing CABG surgery with CPB.