Preoperative C-Reactive Protein Predicts Mid-Term Outcome After Cardiac Surgery

Associations of Inflammatory Biomarkers With the Risk of Morbidity and Mortality After Cardiac Surgery: A Systematic Review and Meta-analysis

BACKGROUND

Although inflammatory biomarkers have been associated with cardiovascular events in nonsurgical settings, these associations have not been systematically addressed in patients undergoing cardiac surgery. This review aimed to evaluate the relationships of inflammatory markers with mortality and adverse cardiovascular events in patients undergoing cardiac surgery.

METHODS

Medline, Embase, and Central databases were systematically searched for studies reporting pre- or postoperative levels of inflammatory biomarkers in patients undergoing cardiac surgery. Outcomes of interest were postoperative mortality, nonfatal myocardial infarction, stroke, congestive heart failure, and major adverse cardiovascular events (MACE). Studies reporting multivariable adjusted risk estimates were included. Risk estimates were pooled with the use of random-effects models and reported as summary odds ratios (ORs).

RESULTS

Among 14,465 citations identified, 29 studies including 29,401 participants met the eligibility criteria. The average follow-up time after surgery was 31 months. Preoperative C-reactive protein (CRP) levels were associated with an increased risk of all-cause mortality (OR 1.88, 95% CI 1.60-2.20; I2 = 19%; 11 studies) and MACE (OR 1.73, 95% CI 1.34-2.24; I2 = 0%; 3 studies). CRP levels measured on postoperative day 6 (OR 7.4, 95% CI 2.90-18.88, 1 study) and day 10 (OR 11.8, 95% CI 3.50-39.78, 1 study) were associated with a higher risk of all-cause mortality. Less, but overall similar, information was available for other inflammatory biomarkers.

CONCLUSIONS

In this large meta-analysis, inflammatory biomarkers measured before or after cardiac surgery were associated with mortality and adverse cardiovascular outcomes in patients undergoing cardiac surgery.

The Role of Preoperative Chronic Statin Therapy in Heart Transplant Receipts-A Retrospective Single-Center Cohort Study

BACKGROUND

Statin therapy has been proven to reduce the risk of cardiovascular events. The objective of our retrospective study was to investigate the relationship between preoperative chronic administration of statins to postoperative 2-month heart transplantation complications.

METHODS

A total number of 38 heart transplantation recipients from the Cardiovascular and Transplant Emergency Institute of Târgu Mureș between May 2014 and January 2021 were included in our study.

RESULTS

In logistic regression, we found a statistical significance between statin treatment and the presence of postoperative complications of any cause (OR: 0.06, 95% CI: 0.008-0.56; p = 0.0128), simultaneously presenting an elevated risk for early-postoperative acute kidney injury (AKI). From the statin group, atorvastatin therapy had a higher risk of type 2 diabetes mellitus (T2DM) development (OR: 29.73, 95% CI: 1.19-741.76; p = 0.0387) and AKI (OR: 29.73, 95% CI: 1.19-741.76; p = 0.0387). C-reactive protein (CRP), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-c) represented risk factors, atorvastatin administration being independently associated with lower CRP values.

CONCLUSIONS

Chronic previous administration of statins represented a protective factor to the development of 2-month postoperative complications of any cause in heart transplant receipts.

Persistent Depletion of Neuroprotective Factors Accompanies Neuroinflammatory, Neurodegenerative, and Vascular Remodeling Spectra in Serum Three Months after Non-Emergent Cardiac Surgery

We hypothesized that the persistent depletion of neuroprotective markers accompanies neuroinflammation and neurodegeneration in patients after cardiac surgery. A total of 158 patients underwent elective heart surgery with their blood collected before surgery (t_baseline) and 24 h (t_24hr), seven days (t_7d), and three months (t_3m) post-surgery. The patients’ serum was measured for markers of neurodegeneration (τau, τaup181–183, amyloid β1-40/β2-42, and S100), atypical neurodegeneration (KLK6 and NRGN), neuro-injury (neurofilament light/heavy, UC-HL, and GFAP), neuroinflammation (YKL-40 and TDP-43), peripheral nerve damage (NCAM-1), neuroprotection (apoE4, BDNF, fetuin, and clusterin), and vascular smoldering inflammation (C-reactive protein, CCL-28 IL-6, and IL-8). The mortality at 28 days, incidence of cerebrovascular accidents (CVA), and functional status were followed for three months. The levels of amyloid β1-40/β1-42 and NF-L were significantly elevated at all time points. The levels of τau, S100, KLK6, NRGN, and NCAM-1 were significantly elevated at 24 h. A cluster analysis demonstrated groupings around amyloids, KLK6, and NCAM-1. YKL-40, but not TDP-43, was significantly elevated across all time points. BDNF, apoE4, fetuin, and clusterin levels were significantly diminished long-term. IL-6 and IL-8 levles returned to baseline at t_3m. The levels of CRP, CCL-28, and Hsp-70 remained elevated. At 3 months, 8.2% of the patients experienced a stroke, with transfusion volume being a significant variable. Cardiac-surgery patients exhibited persistent peripheral and neuronal inflammation, blood vessel remodeling, and the depletion of neuroprotective factors 3 months post-procedure.

Performance of Artificial Intelligence-Based Algorithms to Predict Prolonged Length of Stay after Lumbar Decompression Surgery

Background: Decompression of the lumbar spine is one of the most common procedures performed in spine surgery. Hospital length of stay (LOS) is a clinically relevant metric used to assess surgical success, patient outcomes, and socioeconomic impact. This study aimed to investigate a variety of machine learning and deep learning algorithms to reliably predict whether a patient undergoing decompression of lumbar spinal stenosis will experience a prolonged LOS. Methods: Patients undergoing treatment for lumbar spinal stenosis with microsurgical and full-endoscopic decompression were selected within this retrospective monocentric cohort study. Prolonged LOS was defined as an LOS greater than or equal to the 75th percentile of the cohort (normal versus prolonged stay; binary classification task). Unsupervised learning with K-means clustering was used to find clusters in the data. Hospital stay classes were predicted with logistic regression, RandomForest classifier, stochastic gradient descent (SGD) classifier, K-nearest neighbors, Decision Tree classifier, Gaussian Naive Bayes (GaussianNB), support vector machines (SVM), a custom-made convolutional neural network (CNN), multilayer perceptron artificial neural network (MLP), and radial basis function neural network (RBNN) in Python. Prediction accuracy and area under the curve (AUC) were calculated. Feature importance analysis was utilized to find the most important predictors. Further, we developed a decision tree based on the Chi-square automatic interaction detection (CHAID) algorithm to investigate cut-offs of predictors for clinical decision-making. Results: 236 patients and 14 feature variables were included. K-means clustering separated data into two clusters distinguishing the data into two patient risk characteristic groups. The algorithms reached AUCs between 67.5% and 87.3% for the classification of LOS classes. Feature importance analysis of deep learning algorithms indicated that operation time was the most important feature in predicting LOS. A decision tree based on CHAID could predict 84.7% of the cases. Conclusions: Machine learning and deep learning algorithms can predict whether patients will experience an increased LOS following lumbar decompression surgery. Therefore, medical resources can be more appropriately allocated to patients who are at risk of prolonged LOS.

Sternal wound infections after sternotomy: risk factors, prevention and management

A serious complication after cardiac surgery is sternal wound infection. Although incidence rates vary worldwide, this complication raises significant concern in a certain patient demographic. This article uses risk assessment strategies to identify a high-risk patient profile and draws parallels with positive predictors in the preoperative, intraoperative and postoperative setting. It describes the complexity of sternal wound infections and highlights guidelines on detection and treatment. The optimal goal of this article is to help minimise the incidence of sternal wound complications after sternotomy by discussing recommendations for preoperative, intraoperative and postoperative preventive measures.

C-reactive Protein as a Prognostic Marker of 1-Year Mortality after Transcatheter Aortic Valve Implantation in Aortic Stenosis

Fundamento:

A proteína C-reativa (PCR) é um biomarcador de inflamação preditor de eventos adversos em procedimentos cardiovasculares. Na avaliação do implante da válvula aórtica transcateter (transcatheter aortic valve implantation, TAVI) em relação ao prognóstico de longo prazo ainda é incipiente.

Objetivo:

Avaliar a PCR como marcador prognóstico no primeiro ano pós-TAVI na estenose aórtica (EAo).

Métodos:

A PCR foi avaliada na primeira semana do peroperatório numa coorte de casos retrospectiva com EAo. Correlacionou-se a PCR pré- e pós-TAVI com a mortalidade e foram pesquisados fatores preditores de mortalidade em 1 ano. Realizada regressão de Cox multivariada para identificar os preditores independentes de óbito em 1 ano.

Resultados:

Estudados 130 pacientes submetidos a TAVI, com mediana de idade de 83 anos, sendo 49% deles do sexo feminino. A PCR pré-TAVI elevada (> 0,5 mg/dL) ocorreu em 34,5% dos casos. O pico de PCR foi 7,0 (5,3-12,1) mg/dL no quarto dia. A mortalidade em 1 ano foi 14,5% (n = 19), sendo maior nos grupos com PCR pré-TAVI elevada (68,8% vs 29,1%; p = 0,004) e pico de PCR ≥ 10,0 mg/dL (64,7% vs 30,8%; p = 0,009). Os fatores preditores independentes de mortalidade foram insuficiência renal aguda (IRA) [razão de risco (RR) = 7,43; intervalo de confiança de 95% (IC95%), 2,1-24,7; p = 0,001], PCR pré-TAVI elevada [RR = 4,15; IC95%, 1,3-12,9; p=0,01] e hemotransfusão volumosa [HR = 4,68; 1,3-16,7; p = 0,02].

Conclusões:

A PCR pré-TAVI elevada mostrou-se fator preditor independente de mortalidade no primeiro ano, assim como a ocorrência de IRA e hemotransfusões volumosas.

C-Reactive Protein at Hospital Discharge and 1-Year Mortality in Acute Infective Endocarditis: A Prospective Observational Study

Background: An accurate biomarker at hospital discharge is needed to identify patients with acute infective endocarditis (IE) who are at high risk of mortality. This prospective observational study evaluated the prognostic value of C-reactive protein (CRP).

Methods: Patients with acute IE (n = 343) and hospitalized at 2 university-affiliated medical centers from January 2014 to December 2019 were enrolled. Patients were categorized as having low or high CRP (n = 217 and 126, respectively) at hospital discharge according to the optimal cutoff (CRP = 6.5 mg/L) determined via receiver-operating characteristic curve analysis. The primary endpoint was all-cause death, from hospital discharge to 1 year. The secondary endpoint was the cumulative rate of rehospitalization or paravalvular abscess at 1 year.

Results: At the 12-month follow-up, the mortality rate of the high-CRP group (21.43%) was significantly higher than that of the low-CRP group (2.76%, log-rank P < 0.0001). The multivariate regression analysis indicated that the high-CRP group had a higher excess mortality hazard risk (HR = 4.182; 95% CI: 2.120, 5.211; P < 0.001). The cumulative 1-year incidence of paravalvular abscess of the high-CRP group (11.90%) was significantly higher than that of the low-CRP (5.07%; P = 0.022). The cumulative rate of heart rehospitalizations of the 2 groups were similar (18.25% cf. 14.29%, P = 0.273).

Conclusion: For hospitalized patients with acute IE, a high CRP at discharge suggests a poor prognosis for 1-year mortality and paravalvular abscess.

Platelet-leukocyte aggregate is associated with adverse events after surgical intervention for rheumatic heart disease

Platelet-leukocyte aggregate (PLA) is implicated in the etiology of both vascular lesions and cardiovascular events. This prospective cohort study aimed to examine the prognostic value of PLA for major adverse cardiac and cerebrovascular events (MACCE) and perioperative adverse events (AEs) in patients with rheumatic heart disease undergoing surgical intervention by Cox proportional hazard regression and logistic regression. A total of 244 patients were included, of whom 7 were lost to follow-up. Among the analyzed 237 subjects who completed 3-year follow-up, 30 experienced MACCE and 38 experienced perioperative AEs. Preoperative PLA was higher in subjects who developed MACCE (13.32%) than in those who did not (8.69%, p = 0.040). In multivariate regression, elevated PLA was associated with increased MACCE (hazard ratio 1.51 for each quartile, 95% CI 1.07-2.13; p = 0.020), and perioperative AEs (odds ratio 1.61, 95% CI 1.14-2.26; p = 0.007). The optimal PLA cut-off for predicting MACCE was 6.8%. Subjects with PLA > 6.8% had a higher prevalence of MACCE (17.1% vs. 5.5%, p = 0.009) and perioperative AEs (19.9% vs. 8.6%, p = 0.018). Kaplan-Meier analysis showed shorter MACCE-free survival in patients with PLA > 6.8% (p = 0.007, log rank). Elevated preoperative PLA is associated with increased MACCE and perioperative AEs in patients with rheumatic valve disease undergoing surgical intervention.

Maximizing Interpretability and Cost-Effectiveness of Surgical Site Infection (SSI) Predictive Models Using Feature-Specific Regularized Logistic Regression on Preoperative Temporal Data

This study describes a novel approach to solve the surgical site infection (SSI) classification problem. Feature engineering has traditionally been one of the most important steps in solving complex classification problems, especially in cases with temporal data. The described novel approach is based on abstraction of temporal data recorded in three temporal windows. Maximum likelihood L1-norm (lasso) regularization was used in penalized logistic regression to predict the onset of surgical site infection occurrence based on available patient blood testing results up to the day of surgery. Prior knowledge of predictors (blood tests) was integrated in the modelling by introduction of penalty factors depending on blood test prices and an early stopping parameter limiting the maximum number of selected features used in predictive modelling. Finally, solutions resulting in higher interpretability and cost-effectiveness were demonstrated. Using repeated holdout cross-validation, the baseline C-reactive protein (CRP) classifier achieved a mean AUC of 0.801, whereas our best full lasso model achieved a mean AUC of 0.956. Best model testing results were achieved for full lasso model with maximum number of features limited at 20 features with an AUC of 0.967. Presented models showed the potential to not only support domain experts in their decision making but could also prove invaluable for improvement in prediction of SSI occurrence, which may even help setting new guidelines in the field of preoperative SSI prevention and surveillance.

Effect of Serum C-Reactive Protein Level on Admission to Predict Mortality After Transcatheter Aortic Valve Implantation

The relation between C-reactive protein (CRP) level on admission and mortality after transcatheter aortic valve implantation (TAVI) remains unclear. To evaluate the impact of serum CRP level on mortality after TAVI, we assessed 1,016 patients with CRP who underwent TAVI and 538 patients with high-sensitive CRP (hs-CRP) level who underwent TAVI on admission in the OCEAN (Optimized Transcatheter Valvular Intervention)-TAVI registry. Study population was stratified into 2 groups (high/low), according to the median of CRP and hs-CRP on admission. We assessed the impact of high CRP and hs-CRP level on all-cause death after TAVI. During 2-year follow-up, all-cause death after TAVI was 9.4% in patients with CRP and 11.9% in patients with hs-CRP. Median value of serum CRP was 0.10 mg/dl in both CRP and hs-CRP. Patients with high CRP (>0.10 mg/dl) had significantly higher incidence of all-cause death compared with those with low CRP (11.5% vs 7.6%, log-rank p = 0.015). Multivariate Cox regression analysis with a time-varying covariate demonstrated that high CRP was an independent predictor of all-cause death within the first 3 months (hazard ratio 2.78, 95% CI 1.30 to 5.95) compared with from 3 months to 2 years (hazard ratio 0.80, 95% CI 0.47 to 1.36) (P for interaction = 0.008). Inversely, these results were not observed in the stratification using hs-CRP on admission. In conclusion, high CRP on admission was significantly associated with an increased risk of all-cause death after TAVI, particularly within the first 3 months after TAVI. Risk stratification using CRP may be a simple and useful strategy to identify high-risk patients who undergo TAVI.

The role of preoperative blood parameters to predict the risk of surgical site infection

BACKGROUND

Routine preoperative blood work is not recommended but selected biochemical markers may predict the risk of surgical site infection (SSI). This study examines the association between preoperative biochemical markers and the risk of SSI.

METHODS

This observational cohort study, nested in a randomized controlled trial, was conducted at two tertiary referral centers in Switzerland.

RESULTS

122 (5.8%) of 2093 patients experienced SSI. Preoperative increasing levels of albumin (OR 0.93), CRP (OR 1.34), hemoglobin (OR 0.87) and eGFR (OR 0.90) were significantly associated with the odds of SSI. The same accounts for categorized parameters. The highest area under the curve from ROC curves was 0.62 for albumin. Positive predictive values ranged from 6.4% to 9.5% and negative predictive values from 94.8% to 95.7%. The association of CRP, mildly and moderately decreased eGFR and hemoglobin with the odds of SSI remained significant on multivariate analysis.

CONCLUSIONS

Our results do not support generally delaying elective surgery based on preoperative blood results. However, it may be considered in situations with potentially severe sequelae of SSI.

Acute systemic inflammatory response after cardiac surgery in patients infected with human immunodeficiency virus using clinical and inflammatory markers

BACKGROUND

Immediate post-cardiopulmonary bypass (CPB) immune responses and organ injuries in immune-compromised patients remain poorly documented.

METHOD

Sixty-one consecutive patients (30 HIV seropositive and 31 seronegative), undergoing elective cardiac valve(s) replacement were enrolled, from a single center hospital, after informed consent was obtained. C-reactive protein (CRP) and Erythrocyte sedimentation rate (ESR) were used as biomarkers of acute inflammatory response.

RESULTS

The mean age was similar between the HIV seropositive and negative group. Pre-operatively, CRP (p=0.388) and ESR (p=0.817) were comparable. The CPB events and durations were significantly different between the two groups: duration (p=0.021), clamp aortic duration (p=0.026), bloodtransfusion (p=0.013), total urine output (p=0.035) and peak lactate (p=0.040). Post-operatively, there was significant increased biomarkers level in both groups, albeit not between the groups with a significant negative correlation between the mean change in CRP levels and mechanical ventilation (r=0.548, p=0.002) in the seropositive group (r=0.025, p=0.893). The correlation between pre-operative and post-operative difference in CRP and ICU stay was not significant in both groups. A significant drop (p=<0.001) in CD4 cells was documented post-operatively in the HIV seropositive group.

CONCLUSION

HIV positive patients' post-operative reactions to cardiac surgery supported by CPB are similar to those of HIV seronegative patients.

[Relationship between hyperuricemia and adverse events in patients aged 40 years or older receiving rheumatic aortic valve replacement]

OBJECTIVE

To explore the prognostic value of hyperuricemia for adverse events in patients >40 years old receiving valve replacement surgery for rheumatic aortic valve disease.

METHDS

Consecutive middle-aged and elderly patients receiving aortic valve replacement surgery for rheumatic aortic valve disease between March, 2009 and July, 2013 were recruited in this study. The patients were divided into hyperuricemic group and normouricemic group based on their serum levels of uric acid, and the clinical data and adverse events within 1 year after the surgery were compared between the 2 groups.

RESULTS

A total of 632 consecutive patients were recruited, including 381 patients with hyperuricemia and 251 with normouricemia. The in-hospital mortality rate was significantly higher in hyperuricemic group than in normouricemic group (7.6% vs 2.0%, P=0.002). Serum uric acid levels were negatively correlated with eGFR (r=-0.421, P<0.001) and positively correlated with C-reactive protein level (r=0.093, P=0.025). Multivariate analysis showed that hyperuricemia was independently associated with the in-hospital mortality (OR=3.07, 95%CI: 1.13-8.37, P=0.028) and mortality at 1 year after the surgery (HR=3.14, 95%CI: 1.30-7.62, P=0.011) after adjusting for potential risk factors including age, NYHA III-IV and postoperative acute kidney injury (AKI). Kaplan-Meier analysis showed that the cumulative rate of 1-year mortality after surgery was significantly higher in patients with hyperuricemia (Log-rank=11.73, P=0.001).

CONCLUSION

Hyperuricemia is a predictor of in-hospital and one-year mortality in middle-aged and elderly patients following aortic valve replacement surgery for rheumatic aortic valve disease.

The correlation between preoperative erythrocyte sedimentation rate and postoperative outcome in adult cardiac surgery

Introduction

Over the past decades, it has been recommended that preoperative assessment mainly relies on history and physical examination rather than unnecessary laboratory tests. In Iranian hospitals, erythrocyte sedimentation rate (ESR) has been routinely measured in most of the patients awaiting major surgery, which has in turn exacted heavy costs on the health system. Therefore, the aim of the present study was to assess the preoperative routine measurement of ESR in such patients.

Materials and methods

This is a retrospective study, in which we evaluated the medical files of 620 patients. Patients older than 18 years, who had undergone elective heart surgery in our hospital in 2014, were included in the study. The data associated with demography, heart disease diagnosis, type of surgery, significant preoperative tests, delay or postponing of surgery and the reason for it, type and characteristics of the subspecialty consultation, and finally, postoperative complication and mortality rate were collected and analyzed. The patients were categorized into four groups according to ESR value: normal (<15 mm/h in females or <20 mm/h in males), moderately increased (<40 mm/h), severely increased (≥40 mm/h), and not measured.

Results

Of the 620 patients’ files, 402 were of males and 218 were of females. Demographic values and preoperative characteristics were similar in the four groups. A total of 105 consultations were given to 79 patients preoperatively, where only in five cases, the elevation in ESR was the main reason for consultation. In no other cases did the consultations result in new diagnoses. Overall, postoperative complication and mortality rate were the same in all four groups; in severely increased ESR group, on the other hand, the need for long periods of intensive care unit (ICU) and hospital stays was higher than that of other groups.

Conclusion

It is concluded that elevated preoperative ESR does not cancel or defer the surgery, nor does it help diagnose a new, previously undiagnosed disease. Furthermore, it does not generally affect postoperative morbidity or mortality rate unless increased to ≥40 mm/h, where it can increase postoperative ICU and hospital stay. Ultimately, routine preoperative ESR measurement in patients is not conducive to elective heart surgery.

Perioperative Outcomes, Transfusion Requirements, and Inflammatory Response After Coronary Artery Bypass Grafting With Off-Pump, Mini-Extracorporeal, and On-Pump Circulation Techniques

OBJECTIVES

Mini-extracorporeal circulation (MECC) units were developed to reduce postoperative morbidity, transfusion requirements, and inflammation associated with conventional on-pump coronary artery bypass (ONCAB) surgery without the technical demands of the off-pump (OPCAB) technique. We compared perioperative outcomes and inflammatory mediation among OPCAB, MECC, and ONCAB techniques.

METHODS

We prospectively enrolled 102 patients undergoing elective isolated coronary bypass grafting. Perfusion methods were OPCAB (n = 34), MECC (n = 34), and ONCAB (n = 34). Serial blood samples were collected to measure serum inflammatory markers.

RESULTS

There were no operative deaths or strokes. Total red blood cell (RBC) products used in OPCAB, MECC, and ONCAB patients were 0.676, 1.000, and 1.235 units, respectively. Adjusted (by splined Society of Thoracic Surgeons operative risk score) analysis showed no statistically significant differences in mean RBC product use among the different operative systems (OPCAB vs MECC, P = 0.580; OPCAB vs ONCAB, P = 0.311; MECC vs ONCAB, P = 0.633). Adjusted (by Society of Thoracic Surgeons risk score and baseline level) mean plasma level differences (24 hours postoperative - baseline) of C-reactive protein for OPCAB (117.89; 95% confidence interval [95% CI], 106.23-129.54) and for MECC (124.88; 95% CI, 113.45-136.32) were significantly higher than for ONCAB (98.82; 95% CI, 86.40-111.24). No significant adjusted differences (P = 0.304) in interleukin-6 level changes were observed.

CONCLUSIONS

Off-pump coronary artery bypass and MECC did not significantly reduce mean total RBC transfusion requirements. Off-pump coronary artery bypass and MECC were associated with greater C-reactive protein elevation than ONCAB, suggestive of an increased inflammatory response to each of these techniques.

Biomarkers in Coronary Artery Bypass Surgery: Ready for Prime Time and Outcome Prediction?

Coronary artery bypass surgery (CABG) is still one of the most frequently performed surgical procedures all over the world. The results of this procedure have been constantly improved over the years with low perioperative mortality rates, with relatively low complication rates. To further improve these outstanding results, the clinicians focused their attention at biomarkers as outcome predictors. Although biological testing for disease prediction has already been discussed many times, the role of biomarkers in outcome prediction after CABG is still controversial. In this article, we reviewed the current knowledge regarding the role of genetic and dynamic biomarkers and their possible association with the occurrence of adverse clinical outcomes after CABG. We also took into consideration that the molecular pathway activation and the possible imbalance may affect hard outcomes and graft patency. We analyzed biomarkers classified in two different categories depending on their possibility to change over time: genetic markers and dynamic markers. Moreover, we evaluated these markers by dividing them, into sub-categories, such as inflammation, hemostasis, renin–angiotensin, endothelial function, and other pathways. We showed that biomarkers might be associated with unfavorable outcomes after surgery, and in some cases improved outcome prediction. However, the identification of a specific panel of biomarkers or of some algorithms including biomarkers is still in an early developmental phase. Finally, larger studies are needed to analyze broad panel of biomarkers with the specific aim to evaluate the prediction of hard outcomes and graft patency.

C-REACTIVE PROTEIN IN DIABETIC PATIENTS BEFORE GASTRIC BYPASS AS A POSSIBLE MARKER FOR POSTOPERATIVE COMPLICATION

Background

: Obesity and type 2 diabetes mellitus are associated to inflammatory state, which can be set off by the adipose tissue, once it is a metabolically active organ that can cause a chronic mild inflammatory state.

Aim

: To evaluate the correlation between preoperative C-reactive protein and postoperative complications risk in obese patients (grades II and III) after Roux-en-Y gastric bypass, with and without type 2 diabetes mellitus.

Methods :

Between 2008 and 2013 were analysed 209 patients (107 with diabetes), presenting body mass index >40 kg/m²or >35 kg/m²with comorbidities. During the postoperative period, two groups were evaluated: with and without complications. Preoperative ultra-sensitive C-reactive protein was measured by immunonephelometry method.

Results

: Complications occurred in seven patients (pulmonary thromboembolism, fistula, two cases of suture leak, pancreatitis, evisceration and upper digestive hemorrhage). No statistical significance was found regarding lipid profile and C-reactive protein between patients with and without type 2 diabetes mellitus. When compared to each other, both groups (with and without complications) presented with statistical significance regarding C-reactive protein level (7,2 mg/dl vs 3,7 mg/dl, p=0,016) and had similar weight loss percentage after 3, 6 and 12 months follow-up.

Conclusions

: Preoperative C-reactive protein serum level was higher in the group which presented complications after Roux-en-Y gastric bypass when compared to the group without postoperative complications.

An exploratory study of the patients' sleep patterns and inflammatory response following cardiopulmonary bypass (CPB)

AIMS AND OBJECTIVES

To describe sleep patterns and inflammatory response postCPB, determine sleep pattern changes and inflammatory response over time and explore relationships between sleep and biomarkers of stress and inflammation.

BACKGROUND

Despite the numerous citations of the role of sleep in restoration and health maintenance, a paucity of research exists about this phenomenon in patients undergoing CPB. Specifically, there is no research that has explored correlations between sleep patterns and systemic inflammatory response in adult cardiac surgery patients.

DESIGN

Exploratory, repeated-measures, correlational study.

METHOD

Subjects were recruited from a Midwestern urban hospital. Of the 25 eligible subjects, 16 males and four females completed the study. Wrist actigraphy was used to measure sleep variables. Salivary cortisol and C-reactive protein (C-RP) levels were measured daily. Data were collected during postoperative nights/days 1 through 4 (T1-T4).

RESULTS

Subjects' sleep onset latency (SOL) median scores (0 minute) were within normal range across time periods, whereas median scores for wake after sleep onset (WASO > 270 minutes), sleep fragmentation index (SFI >51%), total sleep time (<153 minutes) and sleep efficiency index (SEI <36%) fell outside the normal ranges. Changes in the median sleep scores over time, however, were not significant at p > 0·05. Median cortisol levels were within normal range (0·3-0·8 μg/dl) from T1-T4, but the C-RP level peaked at T2 (median = 2370 pg/ml). Strong correlations were found: (1) between SFI-cortisol (rs = 0·82), C-RP (rs = 0·65) - WBC (rs = 0·69); (2) between SEI-C-RP (rs = 0·58); (3) between WASO-WBC (rs = 0·48), WASO and cross-clamp time (rs = 0·50); and (4) between SOL-age (rs = -0·55) at p < 0·05.

CONCLUSIONS

Subjects were severely sleep-deprived with inflammatory response exaggerations warranting further investigations using larger sample sizes.

RELEVANCE TO CLINICAL PRACTICE

This study offers a foundation for developing a conceptual model explaining mechanisms of sleep disturbance and inflammatory response postCPB. This knowledge is crucial for testing sleep-promoting interventions to modulate inflammatory responses essential for preventing complications, and restoring health.

Hemoglobin and B-type natriuretic peptide preoperative values but not inflammatory markers, are associated with postoperative morbidity in cardiac surgery: a prospective cohort analytic study

Introduction

Risk stratification in cardiac surgery significantly impacts outcome. This study seeks to define whether there is an independent association between the preoperative serum level of hemoglobin (Hb), leukocyte count (LEUCO), high sensitivity C-reactive protein (hsCRP), or B-type natriuretic peptide (BNP) and postoperative morbidity and mortality in cardiac surgery.

Methods

Prospective, analytic cohort study, with 554 adult patients undergoing cardiac surgery in a tertiary cardiovascular hospital and followed up for 12 months. The cohort was distributed according to preoperative values of Hb, LEUCO, hsCRP, and BNP in independent quintiles for each of these variables.

Results

After adjustment for all covariates, a significant association was found between elevated preoperative BNP and the occurrence of low postoperative cardiac output (OR 3.46, 95% CI 1.53–7.80, p = 0.003) or postoperative atrial fibrillation (OR 3.8, 95% CI 1.45–10.38). For the combined outcome (death/acute coronary syndrome/rehospitalization within 12 months), we observed an OR of 1.93 (95% CI 1.00–3.74). An interaction was found between BNP level and the presence or absence of diabetes mellitus. The OR for non-diabetics was 1.26 (95% CI 0.61–2.60) and for diabetics was 18.82 (95% CI 16.2–20.5). Preoperative Hb was also significantly and independently associated with the occurrence of postoperative low cardiac output (OR 0.33, 95% CI 0.13–0.81, p = 0.016). Both Hb and BNP were significantly associated with the lengths of intensive care unit and hospital stays and the number of transfused red blood cells (p < 0.002). Inflammatory markers, although associated with adverse outcomes, lost statistical significance when adjusted for covariates.

Conclusions

High preoperative BNP or low Hb shows an association of independent risk with postoperative outcomes, and their measurement could help to stratify surgical risk. The ability to predict the onset of atrial fibrillation or postoperative low cardiac output has important clinical implications. Our results open the possibility of designing studies that incorporate BNP measurement as a routine part of preoperative evaluation, and this strategy could improve upon the standard evaluation in terms of reducing adverse postoperative events.

Risks associated with the transfusion of various blood products in aortic valve replacement

BACKGROUND

Patients undergoing cardiac operations often require transfusions of red blood cells, plasma, and platelets. From a statistical point of view, there is a significant collinearity between the components, but they differ in indications for use and composition. This study explores the relationship between the transfusion of different blood components and long-term mortality in patients undergoing aortic valve replacement alone or combined with revascularization.

METHODS

A retrospective single-center study was performed including 1,311 patients undergoing aortic valve replacement. Patients who received more than 7 units of red blood cells, those who died early (7 days), and emergency cases were excluded. Patients were monitored for up to 9.5 years. A broad selection of potential risk factors were analyzed using Cox proportional hazards regression, where transfusion of red blood cells, plasma, and platelets were forced to remain in the model.

RESULTS

The transfusion of red blood cells was not associated with decreased long-term survival (hazard ratio [HR], 1.01; p = 0.520) nor was the transfusion of platelets (HR, 0.946; p = 0.124); however, the transfusion of plasma was (HR, 1.041; p < 0.001). All HRs are per unit of blood product transfused. No increased risk was found for patients undergoing a combined procedure.

CONCLUSIONS

No significant risk for long-term mortality was associated with transfusion of red blood cells during the study period. However, the transfusion of plasma was associated with increased mortality.

Preoperative C-reactive protein can predict early clinical outcomes following elective off-pump CABG surgery in patients with severe left ventricle dysfunction

Purpose:

Atrial fibrillation (AF) is the most common type of arrhythmia following elective off-pump coronary bypass graft (CABG) surgery, occurring on the 2^nd or 3^rd postoperative day. Postoperative atrial fibrillation and early complications may be the cause of long term morbidity and mortality after hospital discharge. High sensitive C-reactive protein (hsCRP) seems to be most significantly associated with cardiovascular disorders. This study was designed to evaluate whether preoperative hsCRP (≥3 mg/dl) can predict post-elective off-pump CABG, AF, and early complications in patients with severe left ventricle dysfunction (Ejection Fraction (EF)<30%).

Methods:

This study was conducted on 104 patients with severe left ventriclar dysfunction (EF < 30%), undergoing elective off-pump CABG surgery during April to September 2011 at the Afshar Cardiovascular Center in Yazd, Iran. Patients undergoing emergency surgery and those with unstable angina, creatinine higher than 2.0 mg/dl, malignancy, or immunosuppressive disease were excluded from the study. The subjects were divided into two groups: Group I with preoperative increased hsCRP (>3 mg/dl) (n=51) and group N with preoperative normal hsCRP (<3 mg/dl) (n=53). We evaluated post-CABG variables including incidence, duration, and frequency of AF, early morbidity (bleeding, infection, vomiting, renal and respiratory dysfunctions), ICU or hospital stay and early mortality. Data were then analyzed by Analysis of Variance (ANOVA), Chi-square and Fisher exact test for quantitative and qualitative variables.

Results:

The average age of the patients was 62.5 years, 75 cases (72.1%) were male, and 39 (37.5%) were female. Postoperative AF occurred in 19 cases (18.2%); 17 cases (33.3%) had hsCRP≥3 mg/dl and 2 cases (3.8%) had hsCRP≤3 mg/dl (P=0.03). Postoperative midsternotomy infection, respiratory dysfunction, and hospital stay were significantly higher in group I compared with group N (P<0.05). No statistical significant differences were identified between the two groups concerning other postoperative complications (bleeding, vomiting, renal dysfunction and ICU stay) (P>0.05).

Conclusion:

Preoperative hsCRP ≥3 mg/dl can predict incidence of postoperative atrial fibrillation and early complications such as midsternotomy infection, respiratory dysfunction, and hospital stay following elective off-pump CABG.

Biomarkers and bacterial pneumonia risk in patients with treated HIV infection: a case-control study

Background

Despite advances in HIV treatment, bacterial pneumonia continues to cause considerable morbidity and mortality in patients with HIV infection. Studies of biomarker associations with bacterial pneumonia risk in treated HIV-infected patients do not currently exist.

Methods

We performed a nested, matched, case-control study among participants randomized to continuous combination antiretroviral therapy (cART) in the Strategies for Management of Antiretroviral Therapy trial. Patients who developed bacterial pneumonia (cases) and patients without bacterial pneumonia (controls) were matched 1∶1 on clinical center, smoking status, age, and baseline cART use. Baseline levels of Club Cell Secretory Protein 16 (CC16), Surfactant Protein D (SP-D), C-reactive protein (hsCRP), interleukin-6 (IL-6), and d-dimer were compared between cases and controls.

Results

Cases (n = 72) and controls (n = 72) were 25.7% female, 51.4% black, 65.3% current smokers, 9.7% diabetic, 36.1% co-infected with Hepatitis B/C, and 75.0% were on cART at baseline. Median (IQR) age was 45 (41, 51) years with CD4+ count of 553 (436, 690) cells/mm³. Baseline CC16 and SP-D were similar between cases and controls, but hsCRP was significantly higher in cases than controls (2.94 µg/mL in cases vs. 1.93 µg/mL in controls; p = 0.02). IL-6 and d-dimer levels were also higher in cases compared to controls, though differences were not statistically significant (p-value 0.06 and 0.10, respectively).

Conclusions

In patients with cART-treated HIV infection, higher levels of systemic inflammatory markers were associated with increased bacterial pneumonia risk, while two pulmonary-specific inflammatory biomarkers, CC16 and SP-D, were not associated with bacterial pneumonia risk.

High-sensitive C-reactive protein predicts outcome after coronary artery bypass

Background: Elevated high-sensitive C-reactive protein is a powerful independent predictor of cardiovascular events. However, there are scant data on its impact on midterm or long-term outcomes of coronary artery bypass grafting.

Method: We analyzed data of 2863 patients who underwent coronary artery bypass in 2006–2007. Early endpoints were hospital mortality and major morbidity. Midterm endpoints were overall mortality, major adverse cardiovascular events, and heart failure.

Results: During hospital stay, 26 patients died and 288 suffered major morbidity. After 3.6 years of follow-up, 56 patients had died, 105 had major adverse cardiovascular events, and 70 developed heart failure. Multivariate analysis revealed every 1 mg·L−1 increase of high-sensitive C-reactive protein was associated with increased odds ratio for early mortality (odds ratio = 2.50, p = 0.002), major morbidity (odds ratio = 1.38, p = 0.02), and hazard ratio for midterm mortality (hazard ratio = 1.68, p = 0.03), major adverse cardiovascular events (hazard ratio = 1.48, p = 0.04), and heart failure (hazard ratio = 1.88, p = 0.01). Preoperative high-sensitive C-reactive protein > 2.5 mg·L−1 predicted higher risks of early (hazard ratio = 2.69, p = 0.02) and midterm mortality (hazard ratio = 1.92, p = 0.02), major morbidity (hazard ratio = 1.46, p = 0.004), major adverse cardiovascular events (hazard ratio = 2.06, p < 0.001), and heart failure (hazard ratio = 1.71, p = 0.03).

Conclusions: Elevated high-sensitive C-reactive protein (>2.5 mg·L−1) predicts poor early and midterm outcomes after coronary artery bypass.

Increased preoperative C-reactive protein levels are associated with inhospital death after coronary artery bypass surgery

Increased C-reactive protein (CRP) is a predictor of cardiovascular risk, but its influence on outcomes after coronary artery bypass grafting surgery (CABG) is still incompletely studied. We studied the association between preoperative CRP and inhospital death after CABG. Patients with acute or chronic infectious or inflammatory disorders, autoimmune diseases, cancer, and prior cardiac surgery were excluded. Seventy-six patients were studied [27.6% with elevated CRP (>3 mg/l)]. Elevated CRP was more frequently found in patients who died than in those who survived (83.3% vs 17.1%, p = 0.003); mean CRP levels were, respectively, 6.5 ± 3.4 vs 2.4 ± 3.5 mg/l (p = 0.03). The hazard ratio of death was 11.7 for elevated CRP, and the ROC curve for the discrimination of death with CRP had an area under the curve of 0.82. An improvement to mortality risk prediction following CABG may be offered by the preoperative analysis of CRP.

[Cardiac biomarkers in perioperative risk stratification]

OBJECTIVES

The field of new cardiac biomarkers has triggered physicians' enthusiasm because of their potential diagnostic and prognostic values for routine clinical practice in the surgical setting. The objective of the present article is to review the role of new cardiac biomarkers and their potential additive clinical value in predicting short- and long-term risk following cardiac and non-cardiac surgery.

DATA SOURCES

A PubMed(®) database research in English and French languages published until June 2010. Keywords were cardiac biomarkers, troponins, cardiac troponin I (cTnI), natriuretic peptides, B-type natriuretic peptide (BNP), C-reactive protein (CRP), multiple markers approach, risk stratification, clinical risk scores.

DATA SYNTHESIS

Numerous publications deal with the diagnostic and prognostic values of new cardiac biomarkers in cardiac and non-cardiac surgical settings and provide an increasing evidence of their interest, validating different hierarchical steps which are mandatory before recommending a wide use of biomarkers for routine practice. Even if the first studies demonstrating an additional prognostic value of serum postoperative cTnI and/or preoperative BNP when compared with clinical predictive models are now available, we still lack data concerning an actual positive impact of new biomarkers measurements on clinical decision making or practice, as well as patient care and outcome.

CONCLUSIONS

While use of new cardiac biomarkers in the perioperative period appears to be a simple and objective tool for risk stratification at the bedside, we still need to remain cautious concerning their additional clinical value on existing predictive models for routine practice.

Protective effects of steroids in cardiac surgery: a meta-analysis of randomized double-blind trials

OBJECTIVE

Cardiac surgery and cardiopulmonary bypass (CPB) induce an acute inflammatory response contributing to postoperative morbidity. The use of steroids as anti-inflammatory agents in surgery using CPB has been tested in many trials and has been shown to have good anti-inflammatory effects but no clear clinical advantages for the lack of an adequately powered sample size. The aim of this study was to evaluate the effects of steroid treatment on mortality and morbidity after cardiac surgery.

DESIGN

A systematic meta-analysis of randomized double-blind trials (RDBs).

SETTING

A university hospital.

PARTICIPANTS

Adult patients who underwent cardiac surgery.

MEASUREMENTS AND MAIN RESULTS

A trial search was performed through PubMed and Cochrane databases from 1966 to January 2009. Among 104 clinical trials reviewed, 31 RDB trials (1,974 patients) were considered suitable to be analyzed. A quality assessment of the trials was performed using the Jadad score. The types of steroid used in these trials were methylprednisolone (51.4%), dexamethasone (34.3%), hydrocortisone (5.7%), prednisolone (2.9%), or a combination of methylprednisolone and dexamethasone (5.7%). Steroid prophylaxis provided a protective effect preventing postoperative atrial fibrillation (odds ratio = 0.56; confidence interval [CI] 0.44-0.72, p < 0.0001), reducing postoperative blood loss (mean difference = -204.2 mL; CI from -287.4 to -121 mL; p < 0.0001), and reducing intensive care unit (mean difference = -6.6 hours; CI from -10.5 to -2.7 hours, p = 0.0007) and overall hospital stay (mean difference = -0.8 days; CI from -1.4 to -0.2 days, p = 0.01). Steroid prophylaxis had no effect on postoperative mortality, mechanical ventilation duration, re-exploration for bleeding, and postoperative infection.

CONCLUSIONS

A systematic review of RDB trials reveals that steroid prophylaxis may reduce morbidity after cardiac surgery and does not increase the risk of postoperative infections.

Preoperative C-reactive protein predicts long-term mortality and hospital length of stay after primary, nonemergent coronary artery bypass grafting

BACKGROUND

Preoperative C-reactive protein (CRP) levels more than 10 mg/l have been shown to be associated with increased morbidity and mortality after cardiac surgery. We examine the value of preoperative CRP levels less than 10 mg/l for predicting long-term, all-cause mortality and hospital length of stay in surgical patients undergoing primary, nonemergent coronary artery bypass graft-only surgery.

METHODS

We examined the association between preoperative CRP levels stratified into four categories (< 1, 1-3, 3-10, and > 10 mg/l), and 7-yr all-cause mortality and hospital length of stay in 914 prospectively enrolled primary, nonemergent coronary artery bypass graft-only surgical patients using a proportional hazards regression model.

RESULTS

Eighty-seven patients (9.5%) died during a mean follow-up period of 4.8 +/- 1.5 yr. After proportional hazards adjustment, the 3-10 and > 10 mg/l preoperative CRP groups were associated with long-term, all-cause mortality (hazards ratios [95% CI]: 2.50 [1.22-5.16], P = 0.01 and 2.66 [1.21-5.80], P = 0.02, respectively) and extended hospital length of stay (1.32 [1.07-1.63], P < 0.001 and 1.27 [1.02-1.62], P = 0.001, respectively).

CONCLUSION

We demonstrate that preoperative CRP levels as low as 3 mg/l are associated with increased long-term mortality and extended hospital length of stay in relatively lower-acuity patients undergoing primary, nonemergent coronary artery bypass graft-only surgery. These important findings may allow for more objective risk stratification of patients who present for uncomplicated surgical coronary revascularization.

Patient-related risk factors for postoperative adverse events

PURPOSE OF REVIEW

The risk of adverse outcome in patients undergoing major surgery is affected both by cardiorespiratory fitness, and the presence and severity of comorbidities. Accurate risk stratification is essential for the identification of patients who may benefit from specific perioperative management strategies or from an augmented level of perioperative care. Risk stratification techniques include risk prediction models, assessment of functional capacity and novel biochemical markers. This review examines the evidence for the use of these different techniques in perioperative patients.

RECENT FINDINGS

There remains considerable variation in the predictive ability of risk stratification models, in part due to the subjective nature of some of the component variables. Whereas a basic assessment of functional capacity using structured questionnaires may be helpful, in patients thought to be at high risk, the most accurate technique may be cardiopulmonary exercise testing, although the strength of the hypothesized relationship between functional capacity and perioperative outcome has not been fully defined. There have been advances in the identification and refinement of biochemical markers for risk prediction, in particular, brain natriuretic peptide and C-reactive protein. Currently, few centres routinely systematically utilize these strategies to risk stratify perioperative patients.

SUMMARY

The development of improved risk stratification techniques would be assisted by large-scale epidemiological studies. Improvements to currently used risk prediction models are likely to result from the use of variables which more objectively measure patient health and fitness than current tools, and may use a combination of all the above techniques to improve predictive accuracy.

Preoperative blood sugar and C-reactive protein associated with persistent discharge after incision and drainage for patients with deep neck abscesses

OBJECTIVES

The aim of this study was to investigate whether preoperative C-reactive protein (CRP) and blood sugar correlated with persistent discharge after incision and drainage for patients with deep neck abscesses.

STUDY DESIGN

Retrospective data analysis.

SETTING

Tertiary referral centre.

PARTICIPANTS

A total of 204 patients who underwent operation for deep neck abscess.

MAIN OUTCOME MEASURES

Persistent discharge after operation.

RESULTS

One hundred seventy patients were included for final analyses. Most of the patients were male (n = 115; 68%) and the average age was 54 years. Using logistic regression analyses, age >55 years [odds ratio (OR): 3.053; P = 0.002], preoperative CRP >15 mg/dL (OR: 2.174; P = 0.027), and preoperative blood sugar >8.3 mmol/L (OR: 3.280; P = 0.001) were independent factors correlated with persistent discharge.

CONCLUSIONS

Older age, elevated preoperative CRP level and blood sugar had a statistically significant association with persistent discharge after operation in deep neck abscesses patients.

Expression of inducible nitric oxide synthase in conduits used in patients with diabetes mellitus undergoing coronary revascularization

BACKGROUND

Expression of inducible nitric oxide synthase (iNOS) is a marker of vascular inflammation which can result in thrombosis and atherosclerosis. This study was undertaken to examine the difference in iNOS expression in the internal mammary artery (IMA) and saphenous veins (SVs) of patients with diabetes mellitus undergoing coronary artery bypass graft (CABG) surgery using both qualitative and quantitative methodology.

METHODS

Segments of IMA and SV harvested in 100 diabetic patients with diabetes mellitus undergoing CABG surgery were fixed in formalin and immunostained to detect the presence of iNOS. Sections were graded using a qualitative score (0 = absence of iNOS expression to 3 = extensive expression of iNOS) and a quantitative computer-aided image analysis (area of staining/area of endothelium). Linear regression analyses were performed to assess the association of the degree of iNOS expression in both the IMA and SV with the type of diabetes control (insulin, oral, diet), and the serum levels of HbAlc, glucose, free fatty acids (ffa), C-reactive protein (CRP), and low-density liproprotein (LDL) at the time of conduit harvest.

RESULTS

The degree of iNOS expression was significantly lower in the IMA compared to the SV by both qualitative (0.88 +/- 0.74 SD IMA vs. 1.38 +/- 0.68 SV; p < 0.0001) and quantitative (11.76 +/- 3.34% IMA vs. 17.10 +/- 2.54% SV; p = 0.01) methods. The Spearman rank correlation analysis showed a highly statistically significant association between the two methodologies (p < 0.0001). There was no correlation between iNOS expression in either the IMA or SV and the type of diabetes control, or levels of HA1c, glucose, ffa, and CRP. However, there was a significant (p = 0.04) correlation between LDL and iNOS expression in the SV graft, but not the IMA.

CONCLUSIONS

iNOS expression is significantly decreased in the IMA compared to the SV in patients with diabetes mellitus undergoing CABG surgery. The degree of iNOS expression is unrelated to the level of glycemic control at the time of conduit harvest, but is associated with serum LDL levels in the SV, but not in the IMA grafts.

Predictive value of C-reactive protein for major postoperative complications following off-pump coronary artery bypass surgery: prospective and observational trial

BACKGROUND

To prospectively investigate the predictive value of the preoperative C-reactive protein (CRP) concentration for major postoperative complications following off-pump coronary artery bypass (OPCAB) surgery.

METHODS AND RESULTS

From January 2007 to December 2007, 185 consecutive patients scheduled for elective OPCAB surgery were allocated to a low-CRP group (n=137, CRP <0.3 mg/dl) and a high-CRP group (n=48, CRP > or = 0.3 mg/dl). The incidence of major postoperative complications, defined as postoperative myocardial infarction, and 5 major morbidity endpoints including permanent stroke, renal dysfunction, any cardiac surgery reoperation, ventilation for more than 48 h, and deep sternal wound infection were assessed and compared. Multivariate logistic regression was used to determine the predictors of major postoperative complications. Patients in the high-CRP group had a significantly higher overall incidence of major postoperative complications, particularly renal dysfunction. In the multivariate logistic regression model, adjusting all the significant univariate predictors, baseline CRP >0.3 mg/dl and preoperative chronic renal failure (CRF) remained as significant independent predictors of major postoperative complications.

CONCLUSIONS

Elevated preoperative CRP level and/or preoperative CRF indicate increased risk of developing major postoperative complications, particularly acute postoperative renal dysfunction in patients undergoing OPCAB surgery.

Clinical utility of peri-operative C-reactive protein testing in general surgery

INTRODUCTION

C-reactive protein (CRP) is an acute-phase protein used clinically to diagnose infectious and inflammatory disease and monitor response to treatment. CRP measurement in the peri-operative period was audited and patterns of change analysed for elective general surgical patients.

PATIENTS AND METHODS

General surgical patients (201) admitted for elective general surgery over a 3-month period were considered for the study. CRP results pre- and postoperatively were recorded, and data on co-morbid conditions and surgical procedure were noted.

RESULTS

CRP was requested pre-operatively on 84% of patients. A high CRP was more likely to be found in patients with co-morbidity. Postoperatively, CRP was requested during the first 3 days on 69% of patients. CRP peaked at postoperative days two or three, and then fell. In patients who had a high pre-operative CRP, the peak CRP was higher and occurred later, than those who had a normal pre-operative CRP.

CONCLUSIONS

CRP requesting pre-operatively is common, but is not recommended in NICE guidelines. Postoperatively, CRP levels rise; as a result, its use as a tool to screen for infection is limited. CRP has a role in diagnosis of infection after the first three postoperative days and in monitoring response to treatment. Therefore, routine use of CRP measurements pre-operatively and in the first 2 or 3 days post-operatively is not recommended. A peri-operative CRP should only be requested if there is a clear clinical indication.

Preoperative unintended weight loss and low body mass index in relation to complications and length of stay after cardiac surgery

BACKGROUND

Several studies reported increased adverse outcomes after cardiac surgery in patients with low body mass index (BMI; in kg/m(2)). Little is known yet, however, about the effect of preoperative unintended weight loss (UWL) in cardiac surgery patients.

OBJECTIVE

We explored the prevalence and effect of UWL in view of low BMI and vice versa adjusted for a validated set of preoperative risks, inflammatory activity, and duration of extracorporeal circulation on postoperative adverse outcome.

DESIGN

A prospective cohort study was performed. Nutritional data of cardiac surgery patients were collected within 24 h of admission and linked to the standard postoperative complication registration database.

RESULTS

The cohort consisted of 331 cases. Multivariate logistic regression analyses showed that preoperative UWL of >or=10% in the past 6 mo (>or=10%UWLin6m) was associated with a prolonged length of stay in the hospital independent from low BMI [odds ratio (OR): 7.06; 95% CI: 1.78, 28.04]. Preoperative BMI <or= 21.0 was associated with an increased incidence of postoperative infections and prolonged stay in the intensive care unit independent from >or=10%UWLin6m (OR: 4.62; 95% CI: 1.20, 17.82; and OR: 5.27; 95% CI: 1.28, 21.76, respectively). Preoperative undernutrition in cardiac surgery patients (>or=10%UWLin6m or BMI <or= 21.0 or both) was present in 9.1% of the study population (4.3% and 4.8%, respectively).

CONCLUSIONS

From this study, we recommend special attention for cardiac surgery patients with preoperative >or=10%UWLin6m or BMI <or= 21.0 because both variables are independently related to adverse outcomes. Preoperative referral to a dietitian for further diagnostic assessment and nutritional treatment is strongly recommended.