Systemic inflammation present in patients undergoing CABG without extracorporeal circulation

Incidence of systemic inflammatory response syndrome and patient outcome following transcatheter edge-to-edge mitral valve repair

OBJECTIVES

Systemic inflammatory response syndrome (SIRS) is a common finding after cardiovascular interventions. Data on the incidence of SIRS and its impact on outcome in patients undergoing transcatheter edge-to-edge mitral valve repair (MV-TEER) for mitral regurgitation (MR) is lacking.

METHODS

From January 2013 to December 2020, 373 patients with moderate or severe MR undergoing MV-TEER were included. SIRS was defined as at least two of the following criteria within 48 h after the procedure: leucocyte count > 12.0 or < 4.0 × 109/l, respiratory rate > 20 breaths per minute or PaCO2 ≤ 4.3 kPa/32 mmHg, heart rate > 90 bpm and temperature > 38.0 °C or < 36.0 °C. The primary endpoint was 3-years all-cause mortality.

RESULTS

SIRS was observed in 49.6% (185/373) of patients. Patients who developed SIRS presented more frequently with NYHA III/IV at baseline [SIRS: 82.4% (149/185) vs. no SIRS: 79.0% (147/188); p = 0.029]. Patients who developed SIRS spent more days on ICU (p < 0.001) and overall length of stay was longer (p < 0.001). Relevant residual MR, defined as MR ≥ III in-hospital, was present more often in patients who developed SIRS [SIRS: 11.3% (20/177) vs. no SIRS: 3.93% (7/178), p = 0.036]. At 3 years, all-cause mortality in the entire population was 33.5% (125/373) with an increased all-cause mortality in patients with SIRS compared to patients without SIRS (HR 1.49, [CI 95% 1.04, 2.13]; p = 0.0264). In the multivariate analysis development of SIRS (HR 1.479 [CI 95% 1.016, 2.154]; p = 0.041) was identified as predictor for 3-years all-cause mortality.

CONCLUSIONS

SIRS is a common finding after MV-TEER occurring in approximately half of patients. SIRS after MV-TEER was associated with a longer in-hospital stay. In addition, we observed an increased 3-years all-cause mortality in patients with SIRS.

Antioxidant activity in off and on-pump coronary artery bypass grafting and valve replacement surgery

OBJECTIVES

Cardiac surgeries initiate oxidative stress, increasing organ dysfunction development and mortality. The present study investigated the superoxide dismutase (SOD) activity, as an antioxidant enzyme, in patients undergoing coronary artery bypass (CABG) and heart valve replacement surgeries.

METHODS

A prospective study was performed on patients with proven coronary artery disease (CAD) or valvular heart disease (VHD) candidates for on- or off-pump CABG and valve replacement surgery. Serum SOD activity was measured preoperatively, at 24 h postoperatively, and at the time of discharge. In addition, echocardiography was performed before surgery and at discharge.

RESULTS

A total of 48, 51, and 47 patients were enrolled in the on-pump, off-pump CABG, and valve replacement groups, respectively. Baseline serum SOD activity showed no significant association with BMI, age, and blood pressure in either CAD or VHD patients. The SOD values decreased at the 24 h postoperative time and then increased at the time of discharge in all groups, except for a slight decrease in the on-pump group. The changes in serum SOD values were not significantly different for the three surgical groups.

CONCLUSIONS

The serum SOD activities fell significantly after CABG and valve replacement surgery. Further investigation is emphasized for the role of SOD in oxidative stress after cardiac surgery.

Appropriate Timing of Coronary Artery Bypass Graft Surgery for Acute Myocardial Infarction Patients: A Meta-Analysis

Background

Currently, percutaneous coronary intervention (PCI) and coronary artery bypass grafting (CABG) are commonly used in the treatment of coronary atherosclerotic heart disease. But the optimal timing for CABG after acute myocardial infarction (AMI) is still controversial. The purpose of this article was to evaluate the optimal timing for CABG in AMI.

Methods

We searched the PubMed, Embase, and Cochrane library databases for documents that met the requirements. The primary outcome was in-hospital mortality. The secondary outcomes were perioperative myocardial infarction (MI) incidence and cerebrovascular accident incidence.

Results

The search strategy produced 1,742 studies, of which 19 studies (including data from 113,984 participants) were included in our analysis. In total, 14 studies compared CABG within 24 h with CABG late 24 h after AMI and five studies compared CABG within 48 h with CABG late 48 h after AMI. The OR of in-hospital mortality between early 24 h CABG and late 24 h CABG group was 2.65 (95%CI: 1.96 to 3.58; P < 0.00001). In the undefined ST segment elevation myocardial infarction (STEMI)/non-ST segment elevation myocardial infarction (NSTEMI) subgroup, the mortality in the early 24 h CABG group (OR: 3.88; 95%CI: 2.69 to 5.60; P < 0.00001) was significantly higher than the late 24 h CABG group. Similarly, in the STEMI subgroup, the mortality in the early 24 h CABG group (OR: 2.62; 95% CI: 1.58 to 4.35; P = 0.0002) was significantly higher than that in the late 24 h CABG group. However, the mortality of the early 24 h CABG group (OR: 1.24; 95%CI: 0.83 to 1.85; P = 0.29) was not significantly different from that of the late 24 h CABG group in the NSTEMI group. The OR of in-hospital mortality between early 48 h CABG and late 48 h CABG group was 1.91 (95%CI: 1.11 to 3.29; P = 0.02). In the undefined STEMI/NSTEMI subgroup, the mortality in the early 48 h CABG group (OR: 2.84; 95%CI: 1.31 to 6.14; P < 0.00001) was higher than the late 48 h CABG group. The OR of perioperative MI and cerebrovascular accident between early CABG and late CABG group were 1.38 (95%CI: 0.41 to 4.72; P = 0.60) and 1.31 (95%CI: 0.72 to 2.39; P = 0.38), respectively.

Conclusion

The risk of early CABG could be higher in STEMI patients, and CABG should be delayed until 24 h later as far as possible. However, the timing of CABG does not affect mortality in NSTEMI patients. There was no statistical difference in perioperative MI and cerebrovascular accidents between early and late CABG.

Association of latent class analysis-derived subphenotypes of acute kidney injury with mortality in critically ill patients with cardiovascular disease: a retrospective cohort study

Background

To explore the potential heterogeneity of acute kidney injury (AKI) and evaluate the prognostic differences among AKI subphenotypes in critically ill patients with cardiovascular diseases.

Methods

Data were extracted from the Medical Information Mart for Intensive Care (MIMIC)-III database. Latent class analysis (LCA) was used to explore the potential subphenotypes of AKI in critically ill patients with cardiovascular diseases. The number of classes was identified by the Bayesian information criterion and entropy. The differences in prognostic ability among the AKI subphenotypes were evaluated by logistic regression analysis.

Result

A total of 7738 AKI patients were enrolled in this study. Using LCA, AKI patients were divided into 4 heterogeneous subphenotypes, which were obviously different from the Kidney Disease: Improving Global Outcomes (KDIGO) stages. Interestingly, class 3 classified by LCA was dominated by stage 2, while the mortality rate in class 3 was significantly different from that in class 1 (15.2% vs. 1.6%, p < 0.05). After further adjustment, the mortality rate in class 3 remained higher than that in class 1, with an odds ratio of 12.31 (95% confidence interval, 8.96–16.89).

Conclusions

LCA was feasible for AKI classification in critically ill patients with cardiovascular disease, and 4 distinct subphenotypes of AKI patients with different prognoses were identified. Our results highlighted the potential heterogeneity of AKI patients, which is worthy of further investigation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12872-022-02587-9.

Impact of Systemic Inflammatory Response Syndrome on Clinical, Echocardiographic, and Computed Tomographic Outcomes Among Patients Undergoing Transcatheter Aortic Valve Implantation

Background

Systemic inflammatory response syndrome (SIRS) is a systemic insult that has been described with many interventional cardiac procedures. The outcomes of patients undergoing transcatheter aortic valve implantation (TAVI) are thought to be influenced by this syndrome not only on short-term, but also on long-term.

Objective

We assessed the association of SIRS to different clinical, echocardiographic, and computed tomographic (CT) outcomes after TAVI.

Methods

Two hundred and twenty-four consecutive patients undergoing TAVI were enrolled in this study. They were assessed for the occurrence of SIRS within the first 48 h after TAVI. Patients were followed-up for short- and long-term clinical outcomes. Serial echocardiographic follow-ups were conducted at 1-week, 6-months, and 1-year. CT follow-up at 1 year was recorded.

Results

Eighty patients (36%) developed SIRS. Among different parameters, only pre-TAVI total leucocytic count (TLC), pre-TAVI heart rate, and post-TAVI systolic blood pressure independently predicted the occurrence of SIRS. The incidence of HALT was not significantly different between both groups, albeit higher among SIRS patients (p = 0.1) at 1-year CT follow-up. Both groups had similar patterns of LV recovery on serial echocardiography. Long-term follow-up showed that all-cause death, cardiac death, and re-admission for heart failure (HF) or acute coronary syndrome (ACS) were significantly more frequent among SIRS patients. Early safety and clinical efficacy outcomes were more frequently encountered in the SIRS group, while device-related events and time-related valve safety were comparable.

Conclusion

Although SIRS implies an early acute inflammatory status post-TAVI, yet its clinical sequelae seem to extend to long-term clinical outcomes.

Atrial inflammation in different atrial fibrillation subtypes and its relation with clinical risk factors

Objective

Inflammation of the atria is an important factor in the pathogenesis of atrial fibrillation (AF). Whether the extent of atrial inflammation relates with clinical risk factors of AF, however, is largely unknown. This we have studied comparing patients with paroxysmal and long-standing persistent/permanent AF.

Methods

Left atrial tissue was obtained from 50 AF patients (paroxysmal = 20, long-standing persistent/permanent = 30) that underwent a left atrial ablation procedure either or not in combination with coronary artery bypass grafting and/or valve surgery. Herein, the numbers of CD45+ and CD3+ inflammatory cells were quantified and correlated with the AF risk factors age, gender, diabetes, and blood CRP levels.

Results

The numbers of CD45+ and CD3+ cells were significantly higher in the adipose tissue of the atria compared with the myocardium in all AF patients but did not differ between AF subtypes. The numbers of CD45+ and CD3+ cells did not relate significantly to gender or diabetes in any of the AF subtypes. However, the inflammatory infiltrates as well as CK-MB and CRP blood levels increased significantly with increasing age in long-standing persistent/permanent AF and a moderate positive correlation was found between the extent of atrial inflammation and the CRP blood levels in both AF subtypes.

Conclusion

The extent of left atrial inflammation in AF patients was not related to the AF risk factors, diabetes and gender, but was associated with increasing age in patients with long-standing persistent/permanent AF. This may be indicative for a role of inflammation in the progression to long-standing persistent/permanent AF with increasing age.

Graphic abstract

Aortic stenosis and diabetes mellitus: An ominous combination

Aortic stenosis and diabetes mellitus are both progressive diseases which, if left untreated, result in significant morbidity and mortality. There is evidence that the prevalence of diabetes is substantially increased in patients with aortic stenosis and those with diabetes have increased rates of progression from mild to severe aortic stenosis. There are good data supporting the hypothesis that aortic stenosis and diabetes mellitus are associated with diabetes mellitus being detrimental towards the quality of life and survival of patients. Thus, a thorough understanding of the pathogenesis of both of these disease processes and the relationship between them aids in designing appropriate preventive and therapeutic approaches. This review aims to give a comprehensive and up-to-date insight into the influence of diabetes mellitus on patients with degenerative aortic stenosis, as well as the prognosis and therapeutic approach to these patients.

Predictive risk factors of acute kidney injury after on-pump coronary artery bypass grafting

Background

Acute kidney injury (AKI) is a common complication after coronary artery bypass grafting (CABG) and increases the risk of short and long-term morbidity and mortality. The aim of our study is to identify preoperative and intraoperative risk factors for development of AKI after primary isolated on-pump CABG.

Methods

In the retrospective study, 210 consecutive patients who underwent primary isolated on-pump CABG from January 2007 to March 2016 were included. The patients were divided into without AKI group (Group 1) and AKI group (Group 2) after operation. The s-Cr levels were recorded pre and postoperatively. The demographics, preoperative and postoperative data were collected from patient's medical profile and analyzed statistically.

Results

AKI developed in 40.5% of the patients (85 patients out of 210 patients). Age (Group 1; Group 2, 63.7±8.6; 67.2±8.2, P=0.004), body surface area (BSA) (Group 1; Group 2, 1.71±0.16; 1.64±0.16, P=0.003), body weight (Group 1; Group 2, 64.1±10.0; 60.7±10.2, P=0.017) were statistically significant for the development of AKI. However, preoperative hemoglobin, blood urea nitrogen (BUN), creatinine, estimated glomerular filtration rate (eGFR) and C-reactive protein (CRP) were not significant. As intraoperative factors, total pump time (TPT), aortic cross clamp time and transfusion were not significant. Female gender (OR 1.88; P=0.044), preoperative proteinuria (OR 2.711; P=0.011) and emergent operation (OR 2.641; P=0.035) were risk factors in univariate analysis. Preoperative proteinuria (OR 2.396; P=0.035) was only risk factor in multivariate analysis.

Conclusions

Preoperative proteinuria was an independent predictor of postoperative AKI in patients undergoing primary isolated on-pump CABG. The accurate risk prediction of AKI after surgery can help clinicians manage more effectively in high-risk patients.

Efficacy of Xuebijing Injection () on Cardiopulmonary Bypass-Associated Pulmonary Injury: A Prospective, Single-center, Randomized, Double Blinded Trial

OBJECTIVE

To evaluate the efficacy of Xuebijing Injection (, XBJ) on the lung injury induced by cardiopulmonary bypass (CPB).

METHODS

Fifty patients undergoing CPB were randomized to either the saline group or XBJ group according to a random number table (25 cases in each group). The patients in the saline group received saline and patients in XBJ group received XBJ at 12 h prior to the operation, at the beginning of the operation, and at 12 h after the second injection. The PaO₂/FiO₂ at extubation 3 days post-operation, duration of ventilation in the intensive care unit (ICU), and lengths of stay in the ICU and hospital were recorded. The levels of inflammatory mediators including interleukin (IL)-1β, IL-8, IL-10, and C-reactive protein (CRP) in bronchoalveolar lavage fluid (BALF) and plasma were measured. The neutrophil count and elastase neutrophil elastase in BALF were also measured. In addition, adverse events were monitored.

RESULTS

The PaO₂/FiO₂ in the XBJ group was higher than that in the saline group from 12 to 72 h post-operation (all P<0.05). The blood levels of IL-1β, IL-8, and CRP in the XBJ group from 12 to 72 h were all significantly lower than those in the saline group (all P<0.05). In contrast, the level of the anti-inflammatory cytokine IL-10 was significantly higher in the XBJ group than in the saline group (P<0.05). In addition, 4 patients presented with atelectasis in the saline group and none in the XBJ group. Ten patients experienced mild acute respiratory distress syndrome (ARDS) during hospitalization, and 5 patients with mild ARDS were in the XBJ group (P<0.05).

CONCLUSION

XBJ shows protective potential against lung injury in patients who undergo CPB surgery, possibly through the downregulation of inflammatory mediators, reduction in neutrophil infiltration, and upregulation of IL-10 (Trial registry: ChiCTR-TRC-14004628).

Sutureless Perceval Aortic Valve Versus Conventional Stented Bioprostheses: Meta-Analysis of Postoperative and Midterm Results in Isolated Aortic Valve Replacement

Background

Aortic stenosis is the most common valvular disease and has a dismal prognosis without surgical treatment. The aim of this meta‐analysis was to quantitatively assess the comparative effectiveness of the Perceval (LivaNova) valve versus conventional aortic bioprostheses.

Methods and Results

A total of 6 comparative studies were identified, including 639 and 760 patients who underwent, respectively, aortic valve replacement with the Perceval sutureless valve (P group) and with a conventional bioprosthesis (C group). Aortic cross‐clamping and cardiopulmonary bypass duration were significantly lower in the P group. No difference in postoperative mortality was shown for the P and C groups (2.8% versus 2.7%, respectively; odds ratio [OR]: 0.99 [95% confidence interval (CI), 0.52–1.88]; P=0.98). Incidence of postoperative renal failure was lower in the P group compared with the C group (2.7% versus 5.5%; OR: 0.45 [95% CI, 0.25–0.80]; P=0.007). Incidence of stroke (2.3% versus 1.7%; OR: 1.34 [95% CI, 0.56–3.21]; P=0.51) and paravalvular leak (3.1% versus 1.6%; OR: 2.52 [95% CI, 0.60–1.06]; P=0.21) was similar, whereas P group patients received fewer blood transfusions than C group patients (1.16±1.2 versus 2.13±2.2; mean difference: 0.99 [95% CI, −1.22 to −0.75]; P=0.001). The incidence of pacemaker implantation was higher in the P than the C group (7.9% versus 3.1%; OR: 2.45 [95% CI, 1.44–4.17]; P=0.001), whereas hemodynamic Perceval performance was better (transvalvular gradient 23.42±1.73 versus 22.8±1.86; mean difference: 0.90 [95% CI, 0.62–1.18]; P=0.001), even during follow‐up (10.98±5.7 versus 13.06±6.2; mean difference: −2.08 [95% CI, −3.96 to −0.21]; P=0.030). We found no difference in 1‐year mortality.

Conclusions

The Perceval bioprosthesis improves the postoperative course compared with conventional bioprostheses and is an option for high‐risk patients.

Evaluation of a new condensed extra-corporeal circuit for cardiac surgery: a prospective randomized clinical pilot study

This prospective randomized clinical pilot study was conducted to evaluate a recently introduced reduced volume CPB system that is coated with the biopassive Xcoating™. Twenty-two patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB), either with a fully heparin-coated CPB circuit (control, n=11) or with an Xcoating™ coated condensed extra-corporeal circuit (CondECC, n=11), were included.

We examined activation of the complement system (C3bc and C4bc), activation of neutrophils (BPI), the acute phase response (interleukin (IL)-6, and acute phase proteins (LBP, AGP, and CRP)), myocardial tissue injury (troponin T), hemolysis (free hemoglobin (FHb)), and clinical outcome parameters. Preoperative risk profiles were identical for both patient groups. All patients went through the procedure without major complications and were discharged from the hospital. FHb and BPI levels at the end of pump support ( p <0.01) and at 15 min after the administration of protamine ( p <0.05) were significantly higher in the control group. In addition, FHb levels were still significantly elevated upon arrival on the cardiothoracic intensive care unit (CICU) in the control group ( p <0.05). C3bc and C4bc, acute phase proteins, IL-6, and troponin T concentrations, and clinical outcome variables were identical in both patient groups.

In conclusion, the evaluated condensed extracorporeal circuit is a flexible and multifunctional CPB sytem that offers safe procedures. Furthermore, the results indicate improved biocompatibility of this option for extracorporeal circulation.

Outcomes of off-pump versus on-pump coronary artery bypass graft surgery in patients with severely dilated left ventricle

BACKGROUND

Currently, off-pump coronary artery bypass (OPCAB) grafting has been the standard procedure for surgical revascularization in patients with coronary artery disease (CAD). This study aimed to examine the safety and applicability of OPCAB compared with on-pump coronary artery bypass (ONCAB) in patients with severely dilated left ventricle.

METHODS

A retrospective study of giant left ventricle patients [left ventricular end diastolic diameter (LVEDD) ≥ VE mm] undergoing coronary bypass grafting from 2009 through 2015 at a single center was conducted. Preoperative and intraoperative risk factors, and postoperative outcomes were analyzed. Survival analysis was carried to analyze survival rate during follow-up.

RESULTS

A total of 24 patients underwent ONCAB, and 26 underwent OPCAB. Both groups had similar preoperative profiles. Two cases from each group died during in-hospital time. In comparison to OPCAB, there was longer operation and post-surgery intubation time and more renal dysfunction in ONCAB group (P<0.05). One-year survival between OPCAB and ONCAB were not significantly different (87.5% vs. 92.3%, P>0.05).

CONCLUSIONS

OPCAB is a safe and feasible alternative for CAD patients with giant left ventricle, offering a significant advantage over ONCAB with regards to renal function, operation duration and length of ventilation.

The Genetic Determinants of Renal Impairment Following Cardiac Surgery

Cardiac surgery is frequently performed, and acute renal dysfunction is a common adverse event following this procedure. Cardiac surgery-related renal injury independently predicts longer hospital stays and greater rates of morbidity and mortality. Although much work has been completed toward better understanding of this phenomenon, the state of knowledge concerning surgery-related renal injury remains limited. Currently, there is no effective paradigm to identify patients who are at risk for this condition; the specific mechanisms of renal injury during surgery are incompletely understood; and few therapies exist to prevent or treat this phenomenon. To better understand this common clinical problem, recent research has focused on the importance of genetic variability within the physiological and patho-physiological systems that underlie renal dysfunction following cardiac surgery. Emphasizing the importance of using genetics to elucidate molecular mechanisms of this disease, this article reviews the current literature on genetic polymorphisms and post cardiac surgery-related renal dysfunction.

Equivalence of the Acute Cytokine Surge and Myocardial Injury after Coronary Artery Bypass Grafting with and without a Novel Extracorporeal Circulation System

Cardiopulmonary bypass (CPB) contributes to a morbidity-inducing systemic Inflammatory response after cardiac surgery. We compared this response in patients receiving coronary artery bypass grafting (CABG) with (CPB group; n = 7) or without (off-pump group; n = 8) the Minimal Extracorporeal Circulation (MECC®) system. Serum concentrations of tumour necrosis factor (TNF)-α, soluble TNF receptors, pro- and anti-inflammatory interleukins (ILs) and other myocardial injury markers were measured after anaesthetic induction, at 1 h, 4 h and 24 h after completing all anastomoses or serially. Soluble TNF receptor type I (sTNFRI) and IL-8 peaked early after CABG in both groups and did not decline. Serum sTNFRI was significantly higher in the CPB compared with the off-pump group at 1 h, whereas IL-8 was significantly lower in the CPB group throughout. The MECC® system, therefore, produces an equivalent acute cytokine response and degree of myocardial injury to off-pump CABG, and may be useful when CABG cannot be performed without CPB.

Wider Perioperative Glycemic Fluctuations Increase Risk of Postoperative Acute Kidney Injury: A Prospective Cohort Study

Acute kidney injury (AKI) is a common complication after cardiac surgery. Recent studies have revealed emerging associations between the magnitude of acute glycemic fluctuations and intensive care unit (ICU) mortality rates. However, the effect of acute glycemic fluctuations on the development of postoperative AKI remains unclear. Thus, we aim to investigate the effect of the magnitude of acute perioperative glycemic fluctuations on the incidence of postoperative AKI.We conducted a prospective cohort study by prospectively obtaining data from all patients who underwent elective coronary artery bypass grafting in a tertiary heart institution from 2009 to 2011. The magnitude of the difference between the highest and lowest perioperative glucose levels within 48 hr was calculated as a measure of perioperative glycemic fluctuation. Patients were divided into 4 groups for analysis based on the magnitude of perioperative glycemic fluctuation-A: 0 to 2 mmol/L; B: >2 to 4 mmol/L; C: >4 to 6 mmol/L; and D: >6 mmol/L. We analyzed the incidence of postoperative AKI, ICU mortality and ICU length of stay as primary and secondary outcomes, respectively. Both univariate and multivariate analyses were used.We analyzed data from 1386 patients. The overall incidence of AKI was 29.9% and increased with wider glycemic fluctuation. The incidence of AKI was statistically highest in Group D (38.3%), followed by Groups C (28.6%), B (21.7%), and A (17.4%), respectively (P[REPLACEMENT CHARACTER]=[REPLACEMENT CHARACTER]0.001). A similar trend was observed among both diabetics and nondiabetics (P[REPLACEMENT CHARACTER]=[REPLACEMENT CHARACTER]0.001 and P[REPLACEMENT CHARACTER]=[REPLACEMENT CHARACTER]0.002, respectively). Multivariate logistic regression showed the magnitude of perioperative glycemic fluctuations to be an independent risk factor in the development of AKI (P < 0.001, odds ratio 1.180, 95% confidence interval 1.116-1.247). ICU length of stay was statistically highest in Group D (58.3[REPLACEMENT CHARACTER]hr) compared with Groups C (44.5[REPLACEMENT CHARACTER]hr), B (37.3[REPLACEMENT CHARACTER]hr), and A (32.8[REPLACEMENT CHARACTER]hr, P[REPLACEMENT CHARACTER]=[REPLACEMENT CHARACTER]0.003). ICU mortality rate was comparable among all 4 groups (P[REPLACEMENT CHARACTER]=[REPLACEMENT CHARACTER]0.172).Wide acute perioperative glycemic fluctuations should be avoided as they are associated with a significantly increased risk of AKI and ICU length of stay in both the diabetics and the nondiabetics.

Routine clinical markers of the magnitude of the systemic inflammatory response after elective operation: a systematic review

BACKGROUND

Operative injury to the body from all procedures causes a stereotypical cascade of neuroendocrine, cytokine, myeloid, and acute phase responses. This response has been examined commonly by the use of cortisol, interleukin-6 (IL-6), white cell count, and C-reactive protein (CRP). We aimed to determine which markers of the systemic inflammatory response were useful in determining the magnitude of injury after elective operations.

METHODS

A systematic review of the literature was performed using surgery, endocrine response, systemic inflammatory response, cortisol, IL-6, white cell count, and CRP. For each analyte the studies were grouped according to whether the operative injury was considered to be minor, moderate, or major and then by the operative procedure.

RESULTS

A total of 164 studies were included involving 14,362 patients. The IL-6 and CRP responses clearly were associated with the magnitude of operative injury and the invasiveness of the operative procedure. For example, the peak CRP response increased from 52 mg/L with cholecystectomy to 123 mg/L with colorectal cancer resection, 145 mg/L with hip replacement, 163 mg/L after abdominal aortic aneurysm repair, and 189 mg/L after open cardiac surgery. There also appeared to be a difference between minimally invasive/laparoscopic and open procedures such as cholecystectomy (27 vs 80 mg/L), colorectal cancer resection (97 vs 133 mg/L), and aortic aneurysm repair (132 vs 180 mg/L).

CONCLUSION

Peak IL-6 and CRP concentrations consistently were associated with the magnitude of operative injury and operative procedure. These markers may be useful in the objective assessment of which components of Enhanced Recovery after Surgery are likely to improve patient outcome and to assess the possible impact of operative injury on immune function.

AKI associated with cardiac surgery

Approximately 18% of patients undergoing cardiac surgery experience AKI (on the basis of modern standardized definitions of AKI), and approximately 2%-6% will require hemodialysis. The development of AKI after cardiac surgery portends poor short- and long-term prognoses, with those developing RIFLE failure or AKI Network stage III having an almost 2-fold increase in the risk of death. AKI is caused by a variety of factors, including nephrotoxins, hypoxia, mechanical trauma, inflammation, cardiopulmonary bypass, and hemodynamic instability, and it may be affected by the clinician's choice of fluids and vasoactive agents as well as the transfusion strategy used. The risk of AKI may be ameliorated by avoidance of nephrotoxins, achievement of adequate glucose control preoperatively, and use of goal-directed therapy hemodynamic strategies. Remote ischemic preconditioning is an exciting future strategy, but more work is needed before widespread implementation. Unfortunately, there are no pharmacologic agents known to reduce the risk of AKI or treat established AKI.

Sulforaphane pretreatment prevents systemic inflammation and renal injury in response to cardiopulmonary bypass

OBJECTIVES

Systemic inflammatory responses are a major cause of morbidity and mortality in patients undergoing cardiac surgery with cardiopulmonary bypass. However, the underlying molecular mechanisms for systemic inflammation in response to cardiopulmonary bypass are poorly understood.

METHODS

A porcine model was established to study the signaling pathways that promote systemic inflammation in response to cardiac surgery with cardiopulmonary bypass under well-controlled experimental conditions. The influence of sulforaphane, an anti-inflammatory compound derived from green vegetables, on inflammation and injury in response to cardiopulmonary bypass was also studied. Intracellular staining and flow cytometry were performed to measure phosphorylation of p38 mitogen-activated protein kinase and the transcription factor nuclear factor-κB in granulocytes and mononuclear cells.

RESULTS

Surgery with cardiopulmonary bypass for 1 to 2 hours enhanced phosphorylation of p38 (2.5-fold) and nuclear factor-κB (1.6-fold) in circulating mononuclear cells. Cardiopulmonary bypass also modified granulocytes by activating nuclear factor-κB (1.6-fold), whereas p38 was not altered. Histologic analyses revealed that cardiopulmonary bypass promoted acute tubular necrosis. Pretreatment of animals with sulforaphane reduced p38 (90% reduction) and nuclear factor-κB (50% reduction) phosphorylation in leukocytes and protected kidneys from injury.

CONCLUSIONS

Systemic inflammatory responses after cardiopulmonary bypass were associated with activation of p38 and nuclear factor-κB pathways in circulating leukocytes. Inflammatory responses to cardiopulmonary bypass can be reduced by sulforaphane, which reduced leukocyte activation and protected against renal injury.

Bactericidal/permeability-increasing protein in host defense and its efficacy in the treatment of bacterial sepsis

The 55-kD bactericidal/permeability-increasing protein (BPI) is a neutrophil-derived polypeptide belonging to a family of lipid and endotoxin binding proteins. BPI is composed of two functionally distinct structural domains: a potently antibacterial and antiendotoxin ∼ 20-kD aminoterminal half, and an opsonic carboxy-terminal portion. In multiple animal models, a recombinant amino-terminal fragment of BPI (rBPI21) is nontoxic and protects against gram-negative bacteria and endotoxin. In humans, rBPI21 is also nontoxic and nonimmunogenic and has undergone phase II/III clinical trials with apparent therapeutic benefit.

Obstacles in haemocompatibility testing

ISO 10993-4 is an international standard describing the methods of testing of medical devices for interactions with blood for regulatory purpose. The complexity of blood responses to biomaterial surfaces and the variability of blood functions in different individuals and species pose difficulties in standardisation. Moreover, in vivo or in vitro testing, as well as the clinical relevance of certain findings, is still matter of debate. This review deals with the major remaining problems, including a brief explanation of surface interactions with blood, the current ISO 10993 requirements for testing, and the role of in vitro test models. The literature is reviewed on anticoagulation, shear rate, blood-air interfaces, incubation time, and the importance of evaluation of the surface area after blood contact. Two test categories deserve further attention: complement and platelet function, including the effects on platelets from adhesion proteins, venipuncture, and animal derived- blood. The material properties, hydrophilicity, and roughness, as well as reference materials, are discussed. Finally this review calls for completing the acceptance criteria in the ISO standard based on a panel of test results.

Changes in anti-heat shock protein 27 antibody and C-reactive protein levels following cardiac surgery and their association with cardiac function in patients with cardiovascular disease

The relationship between serum anti-heat shock protein (Hsp)27 antibody and high sensitive C-reactive protein (hs-CRP) levels and indices of cardiac function were investigated in patients undergoing coronary artery bypass grafting (CABG) or heart valve replacement. The changes in anti-Hsp27 antibody titers and hs-CRP levels were compared among patients undergoing off-pump and on-pump CABG or valvular heart replacement. Fifty-three patients underwent off-pump, on-pump CABG, and heart valvular replacement in each group. Serum anti-Hsp27 titers and hs-CRP values were measured 24 h before and after the operation and at discharge. Echocardiography was performed before surgery and before discharge. The results were compared with values from 83 healthy controls. hs-CRP levels increased and anti-Hsp27 antibody decreased following surgery (P < 0.001 and P < 0.05, respectively), although these changes were independent of operative procedure (P = 0.361 and P = 0.120, respectively). Anti-Hsp27 antibody levels were higher at the time of discharge (P = 0.016). Only in coronary patients were anti-Hsp27 antibody levels negatively associated with E/E' (r = -0.268, P = 0.022), a marker of pulmonary capillary wedge pressure. In conclusions, anti-Hsp27 antibody levels are associated with indices of cardiac function in coronary patients. Cardiopulmonary bypass had no significant effect on the induction of changes in anti-Hsp27 levels. Moreover, anti-Hsp27 antibody levels fell in all groups postoperatively; this may be due to the formation of immune complexes of antigen-antibody, and antibody levels were higher at the time of discharge.

[Ischaemic cardiogenic shock. Where do we stand in 2012?]

With a stable frequency (about 5% of acute coronary syndromes) and a mortality of nearly 45%, cardiogenic shock (CS), especially when it occurs in the immediate waning of myocardial infarction, still represents a therapeutic challenge. In this review, will be detailed the actual epidemiologic data of CS, its physiopathology and the different modalities of treatments available to the interventional cardiologist, especially the coronary revascularisation and the percutaneous left ventricular assistance, whether by intra-aortic balloon counterpulsation or by more complex systems.

[Results of coronary artery bypass grafting with left ventricular dysfunction (comparison of off-pump versus on-pump)]

BACKGROUND

The aim of this study was to compare the results of myocardial revascularisation with or without cardiopulmonary bypass in patients with impaired left ventricular function.

PATIENTS AND METHODS

Five hundred and sixteen consecutive patients who underwent coronary artery bypass grafting from January 2000 through December 2007 were analyzed retrospectively. One hundred and eight cases had a left ventricular EF (ejection fraction) of 45% or less. Of these patients, 78 underwent conventional coronary artery bypass (CCABG) and 30 underwent off-pump procedure (OCABG). The CCABG group received 300IU/kg of heparin while the OCABG received 100IU/kg. The off-pump coronary surgery was carried out using a tissue stabilizer Octopus II. Different pre-, per- and postoperative variables were evaluated among both groups. Statistical analysis was performed by SPSS 11.5. The variables were compared between these two groups using univariate analysis (Chi(2) test, Fisher's test exact) for qualitative variable and (Student's t test, Mann-Whitney's test) for quantitative variable.

RESULTS

Patients profiles and risk factors were similar among both groups except for age (CCABG: 57.8±9.2 year vs OCABG: 52±9.9 year; P=0.004) and left ventricular EF (CCABG: 37.4±6.3% vs OCABG: 34±7.8%; P=0.02). The number of grafts performed per patient was significantly more among patients who underwent extracorporeal circulation (CCABG: 2.53±0.7 graft/patient vs OCABG: 1.77±0.8 graft/patient; P<0.0001). The hospital mortality was more among CCABG group 9% vs 3.3% in OCABG but the difference was not significant (P=0.3). However, the operative time and the operative room stay were long in CCABG (252±61min vs 175±38min; P<0.0001 - 389±70min vs 298±54min; P<0.0001). The ventilation time was also long in CCABG (32.3±67hour vs 10.4±5.9hour; P=0.15). There was more postoperative myocardial infarction in CCABG (P=0.008), but the EF increased and was better in CCABG.

CONCLUSION

Off-pump coronary artery bypass surgery provides satisfactory operative results for most patients with reduced left ventricular function. Prospective and randomly study will be necessary before concluding.

Cardiac surgery-associated acute kidney injury

Cardiac surgery-associated acute kidney injury (AKI) is a major health problem that is extremely common and has a significant effect on cardiac surgical outcomes. AKI occurs in nearly 30 % of patients undergoing cardiac surgery, with about 1-2 % of these ultimately requiring dialysis. The development of AKI predicts a significant increase in morbidity and mortality independent of other risk factors. The pathogenetic mechanisms associated with cardiac surgery-associated AKI include several biochemical pathways, of which the most important are hemodynamic, inflammatory and nephrotoxic factors. Risk factors for AKI have been identified in several models, and these facilitate physicians to prognosticate and develop a strategy for tackling patients predisposed to developing renal dysfunction. Effective therapy of the condition is still suboptimal, and hence the accent has always been on risk factor modification. Thus, strategies for reducing preoperative anemia, perioperative blood transfusions and surgical re-explorations may be effective in attenuating the incidence and severity of this complication.

The role of procalcitonin and N-terminal pro-B-type natriuretic peptide in predicting outcome after cardiac surgery

OBJECTIVE(S)

Determine the thresholds of procalcitonin (PCT) and N-terminal pro-B-type natriuretic peptide (Nt-pro-BNP) associated with poor prognosis after heart surgery with CPB.

DESIGN

Prospective observational study.

SETTING

Academic Medical Center Habib Bourguiba.

PARTICIPANTS

Adult patients consecutively operated for coronary or valve surgery with CPB, elective or semi-urgent.

INTERVENTIONS

Serum concentrations of PCT and Nt-pro-BNP were determined before and after CPB, in the fourth postoperative hour (H4) and every day during the first 4 days. Receiver-operating characteristic curves and cut-off values were used to assess the ability of these markers to predict length of intensive care unit (ICU) stay >3 days.

MEASUREMENTS AND MAIN RESULTS

Forty patients were included in the study. Systemic inflammatory response syndrome (SIRS) occurred in 35 (87.5%) patients. Seventeen of them (42.5%) showed severe SIRS. Significantly higher serum concentrations of Nt-pro-BNP and PCT were found in patients with severe SIRS. Receiver operating characteristic (ROC) analysis showed that the threshold of PCT was 0.737 ng/mL and that of Nt-pro-BNP was 1235 pg/mL on day 1 could predict an ICU stay of more than 3 days. The association of Nt-pro-BNP to procalcitonin (p=0.009) better predicted the ICU stay than PCT alone (p=0.02) or Nt-pro-BNP alone (p=0.03). The best combination is Nt-pro-BNP + PCT + C-reactive protein (CRP) (p=0.007).

CONCLUSIONS

PCT and Nt-pro-BNP on day 1 may be associated with severe SIRS and predict the length of stay. A biomarker approach combining PCT, CRP and BNP is superior to a traditional single marker for predicting ICU stay.

Comparison of the clinical application of reactive oxygen species and inflammatory markers in patients with endocarditis

INTRODUCTION

Infective endocarditis (IE) is still connected with high operative mortality. Inflammatory markers are commonly used in monitoring patient clinical condition. Respiratory burst and reactive oxygen species (ROS) are the main way of pathogen elimination. Specificity of this process in the aspect of bacterial infection is the key for correlation assessment between ROS and inflammatory markers in patients with IE. In the study, assessment of ROS as a clinical indicator in IE was conducted.

MATERIAL AND METHODS

During 2007/2008 in the Cardiosurgical Clinic of the Medical University in Lodz there were 20 patients operated on for IE. The examined population consisted of 13 men and 7 women, aged from 23 to 74 years. Inflammatory markers - leukocytosis (WBC), C-reactive protein (CRP), procalcitonin (PCT) and erythrocyte sedimentation rate (ESR) - were assessed preoperatively, on the 3(rd), 7(th), 12(th) and 21(st) day. Simultaneously, with the second venous blood sample chemiluminescence (luminal enhanced whole blood chemiluminescence) was carried out and used to assess ROS production. The results were analyzed statistically.

RESULTS

Positive correlation between ESR, CRP and ROS in the preoperative period was confirmed. An increase in ROS and a statistically significant increase in inflammatory markers on the 3(rd) day were observed. The ROS normalized on the 12(th) day. Marked individual variability was specific for the inflammatory markers. Despite the significant decrease, not all of them achieved a normal level at the last control point.

CONCLUSIONS

Assessment of ROS seems to be a universal parameter with possible application in patients with IE.

Systemic inflammatory response syndrome predicts increased mortality in patients after transcatheter aortic valve implantation

AIMS

The outcome of patients undergoing surgical or interventional therapy is unfavourably influenced by severe systemic inflammation. We assessed the impact of a systemic inflammatory response syndrome (SIRS) on the outcome after transcatheter aortic valve implantation (TAVI).

METHODS AND RESULTS

One hundred and fifty-two high-risk patients (mean age: 80.5 ± 6.5 years, mean logistic EuroSCORE: 30.4 ± 8.1%) with symptomatic severe aortic stenosis underwent TAVI. Proinflammatory cytokines [interleukin-6 (IL-6) and interleukin-8 (IL-8)], and acute phase reactants [C-reactive protein (CRP) and procalcitonin (PCT)] were measured at baseline and 1, 4, 24, 48, 72 h, and 7 days after TAVI. Sixty-one of 152 patients developed SIRS during the first 48 h after TAVI. Systemic inflammatory response syndrome patients were characterized by leucocytosis ≥12 × 10(9)/L (83.6 vs. 12.1%; P < 0.001), hyperventilation (80.3 vs. 35.2%; P < 0.001), tachycardia (37.7 vs. 9.9%; P < 0.001), and fever (31.1 vs. 3.3%; P < 0.001) compared with patients without SIRS. Furthermore, the occurrence of SIRS was characterized by a significantly elevated release of IL-6 and IL-8 with subsequent increase in the leucocyte count, CRP, and PCT. Major vascular complications [odds ratio (OR) 5.1, 95% confidence interval (CI): 1.3-19.6; P = 0.018] and the number of ventricular pacing runs (OR 1.7, 95% CI: 1.1-2.8; P = 0.025) were independent predictors of SIRS. The occurrence of SIRS was related to 30-day and 1-year mortality (18.0 vs. 1.1% and 52.5 vs. 9.9%, respectively; P < 0.001) and independently predicted 1-year mortality risk (hazard ratio: 4.3, 95% CI: 1.9-9.9; P < 0.001).

CONCLUSIONS

SIRS may occur after TAVI and is a strong predictor of mortality. The development of SIRS could be easily identified by a significant increase in the leucocyte count shortly after TAVI.

The cellular and molecular origin of reactive oxygen species generation during myocardial ischemia and reperfusion

Myocardial ischemia-reperfusion injury is an important cause of impaired heart function in the early postoperative period subsequent to cardiac surgery. Reactive oxygen species (ROS) generation increases during both ischemia and reperfusion and it plays a central role in the pathophysiology of intraoperative myocardial injury. Unfortunately, the cellular source of these ROS during ischemia and reperfusion is often poorly defined. Similarly, individual ROS members tend to be grouped together as free radicals with a uniform reactivity towards biomolecules and with deleterious effects collectively ascribed under the vague umbrella of oxidative stress. This review aims to clarify the identity, origin, and progression of ROS during myocardial ischemia and reperfusion. Additionally, this review aims to describe the biochemical reactions and cellular processes that are initiated by specific ROS that work in concert to ultimately yield the clinical manifestations of myocardial ischemia-reperfusion. Lastly, this review provides an overview of several key cardioprotective strategies that target myocardial ischemia-reperfusion injury from the perspective of ROS generation. This overview is illustrated with example clinical studies that have attempted to translate these strategies to reduce the severity of ischemia-reperfusion injury during coronary artery bypass grafting surgery.

Comparison of the effects of pulsatile cardiopulmonary bypass, non-pulsatile cardiopulmonary bypass and off-pump coronary artery bypass grafting on the inflammatory response and S-100beta protein

Background: We aimed to investigate the effects of off-pump coronary artery bypass grafting, pulsatile cardiopulmonary bypass, and non-pulsatile cardiopulmonary bypass techniques on the inflammatory response and the central nervous system in the current study.

Methods: A total of 32 patients who were scheduled for elective coronary artery bypass graft surgery were included in the study. The patients were allocated into three different groups according to the perfusion techniques used during the cardiopulmonary bypass procedure as follows: off-pump coronary artery bypass grafting group (n=10); pulsatile cardiopulmonary bypass group (n=11); and non-pulsatile cardiopulmonary bypass group (n=11). Serum interleukin-6, interleukin-8, tumor necrosis factor-alpha and S-100beta levels were measured preoperatively, and at 0, 6, and 24 hours postoperatively.

Results: The postoperative increase in the levels of interleukin-6 and interleukin-8 was significantly lower in the off-pump group compared to the other two groups (p<0.05), while there was no significant difference in tumor necrosis factor-alpha levels between the groups. Postoperative S-100β levels, an indicator of cerebral injury, was significantly lower in the off-pump CABG group compared to the other two groups (p<0.05).

Conclusion: We found that off-pump coronary artery bypass grafting had less negative effects on inflammatory response and central nervous system compared to pulsatile cardiopulmonary bypass and non-pulsatile cardiopulmonary bypass techniques.

Perioperative conditions affect long-term hypertrophic scar formation

Corticosteroids are widely used as treatment for excessive scarring by intralesional injection with variable success rates. It is conceivable that systemically administered corticosteroids affect a wider range of inflammatory processes that influence wound healing and may be more successful in preventing hypertrophic scar formation. To study this presumption, we have used a standardized model of presternal scars caused by cardiothoracic surgery through a median sternotomy incision. During cardiac surgery with cardiopulmonary bypass, 1 mg/kg dexamethasone was administered preoperatively, and 0.5 mg/kg 8 hours postoperatively. The presternal scars were evaluated prospectively 2, 4, 6, 12, and 52 weeks postoperatively at standardized measuring points. The height and width of the scars were measured 12 and 52 weeks postoperatively using both a slide caliper and a 7.5-MHz ultrasound probe. Cardiopulmonary bypass was used in 31 of the 43 participants. Eleven patients (35%) in the dexamethasone group developed clinical hypertrophic scars compared with 4 patients (33%) in the control group. These differences were not statistically significant. However, cranial scars became significantly wider in the dexamethasone group compared with the control group (P = 0.04). Twelve weeks postoperatively scars were significantly higher in the dexamethasone group, both cranial (P = 0.05) and caudal (P = 0.03). The differences in scar width and height were mainly present in patients that developed hypertrophic scars. The present results suggest that administration of high-dose perioperative dexamethasone does not prevent hypertrophic scar formation. Its use together with the cardiopulmonary bypass, however, did affect scar dimensions negatively up to 52 weeks after surgery. These findings contribute to the concept of the involvement of perioperative immunologic responses in the etiology of hypertrophic scar formation.

Whole blood transcriptomics in cardiac surgery identifies a gene regulatory network connecting ischemia reperfusion with systemic inflammation

Background

Cardiac surgery with cardiopulmonary bypass (CS/CPB) is associated with increased risk for postoperative complications causing substantial morbidity and mortality. To identify the molecular mechanisms underlying CS/CPB-induced pathophysiology we employed an integrative systems biology approach using the whole blood transcriptome as the sentinel organ.

Methodology/Principal Findings

Total RNA was isolated and globin mRNA depleted from whole blood samples prospectively collected from 10 patients at time points prior (0), 2 and 24 hours following CS/CPB. Genome-wide transcriptional analysis revealed differential expression of 610 genes after CS/CPB (p<0.01). Among the 375 CS/CPB-upregulated genes, we found a gene-regulatory network consisting of 50 genes, reminiscent of activation of a coordinated genetic program triggered by CS/CPB. Intriguingly, the highly connected hub nodes of the identified network included key sensors of ischemia-reperfusion (HIF-1alpha and C/EBPbeta). Activation of this network initiated a concerted inflammatory response via upregulation of TLR-4/5, IL1R2/IL1RAP, IL6, IL18/IL18R1/IL18RAP, MMP9, HGF/HGFR, CalgranulinA/B, and coagulation factors F5/F12 among others. Differential regulation of 13 candidate genes including novel, not hitherto CS/CBP-associated genes, such as PTX3, PGK1 and Resistin, was confirmed using real-time quantitative RT-PCR. In support of the mRNA data, differential expression of MMP9, MIP1alpha and MIP1beta plasma proteins was further confirmed in 34 additional patients.

Conclusions

Analysis of blood transcriptome uncovered critical signaling pathways governing the CS/CPB-induced pathophysiology. The molecular signaling underlying ischemia reperfusion and inflammatory response is highly intertwined and includes pro-inflammatory as well as cardioprotective elements. The herein identified candidate genes and pathways may provide promising prognostic biomarker and therapeutic targets.

Off-pump surgery does not eliminate microalbuminuria or other markers of systemic inflammatory response to coronary artery bypass surgery

OBJECTIVE

To evaluate whether off-pump surgery attenuates microalbuminuria and other markers of systemic inflammatory response to coronary artery bypass surgery as compared to surgery performed using cardiopulmonary bypass.

DESIGN

Forty-three adult patients undergoing elective coronary artery bypass grafting surgery were operated on with or without cardiopulmonary bypass (CPB). Microalbuminuria, serum C-reactive protein, and oxygenation and lung function parameters were measured at several time points until the first postoperative morning.

RESULTS

The urinary albumin/creatinine ratio was low in both groups before surgery, but reached a maximum level at the end of CPB or just after opening the last coronary artery clamp in the off-pump group (p<0.05). The urinary albumin/creatinine ratio remained slightly elevated in both groups until the morning after the operation (p<0.05). There were no statistical differences between groups. Serum C-reactive protein remained at the initial level the evening after the operation, but increased by the first postoperative morning in both groups (p<0.001). The alveolar-arterial gradient for oxygen partial pressure rose significantly after the operation in the intensive care unit in both groups (p<0.0001). The shunt fraction of the pulmonary circulation did not change in either group.

CONCLUSIONS

Off-pump coronary artery surgery did not prevent the acute phase inflammatory response measured in the present study. The acute phase inflammatory response after coronary artery bypass surgery is more likely a response to the surgical trauma itself rather than to CPB.

The long pentraxin 3 in cardiac surgery: Distinct responses in “on-pump” and “off-pump” patients

OBJECTIVE

Pentraxin 3 (PTX3) is a newly identified acute phase reactant with non-redundant functions in innate immunity. The purpose of this study was to assess the kinetics of release of PTX3 in cardiac surgical patients, operated on either with or without the use of cardiopulmonary bypass (CPB).

DESIGN

Thirty-four patients, seventeen in each group, were randomly assigned to CABG surgery performed either with ("on-pump") or without ("off-pump") CPB. Blood samples were collected both during and after the operation up to the 7(th) day.

RESULTS

In patients operated on with the use of CPB, PTX3 levels increased throughout the operation. Compared to baseline levels the highest PTX3 value (p<0.000) was attained on the 1(st) postoperative day in both "on-pump" and "off-pump" patients. In contrast to CPB patients, however, PTX3 levels in the latter group declined slowly, remaining elevated as long as the 3(rd) postoperative day (p<0.042).

CONCLUSIONS

Operations performed with the use of CPB are associated with a more pronounced release of PTX3 immediately after operation.

Off-pump coronary artery bypass surgery and acute kidney injury: a meta-analysis of randomized and observational studies

BACKGROUND

Acute kidney injury (AKI) after coronary artery bypass grafting (CABG) is associated with significant morbidity and mortality. Controversy exists regarding whether an off-pump technique can reduce post-CABG renal injury.

STUDY DESIGN

Systematic review and meta-analysis.

SETTING & POPULATION

Adult patients undergoing CABG.

SELECTION CRITERIA FOR STUDIES

MEDLINE, EMBASE, Cochrane Renal Library, and Google Scholar were searched in May 2008 for randomized controlled trials (RCTs) and observational studies comparing off-pump CABG (OPCAB) with conventional CABG (CAB) for renal outcomes. Studies involving patients on long-term renal replacement therapy (RRT) were excluded.

INTERVENTION

OPCAB.

OUTCOMES

Primary outcomes were overall AKI and AKI requiring RRT.

RESULTS

22 studies (6 RCTs and 16 observational studies) comprising 27,806 patients met the inclusion criteria. The pooled effect from both study cohorts showed a significant reduction in overall AKI (odds ratio [OR], 0.57; 95% confidence interval [CI], 0.43 to 0.76; P for effect < 0.001; I(2) = 67%; P for heterogeneity < 0.001) and AKI requiring RRT (OR, 0.55; 95% CI, 0.43 to 0.71; P for effect < 0.001; I(2) = 0%; P for heterogeneity = 0.5) in the OPCAB group compared with the CAB group. In RCTs, overall AKI was significantly reduced in the OPCAB group (OR, 0.27; 95% CI, 0.13 to 0.54); however, no statistically significant difference was noted in AKI requiring RRT (OR, 0.31; 95% CI, 0.06 to 1.59). In the observational cohort, both overall AKI (OR, 0.61; 95% CI, 0.45 to 0.81) and AKI requiring RRT (OR, 0.54; 95% CI, 0.40 to 0.73) were significantly less in the OPCAB group. RCTs were noted to be underpowered and biased toward recruiting low-risk patients. Sensitivity analysis restricted to good-quality studies showed a significant reduction in AKI.

LIMITATIONS

Lack of uniform AKI definition in the included studies, heterogeneity for overall AKI outcome.

CONCLUSIONS

Analysis of the current evidence suggests a reduction in AKI using the OPCAB technique; however, studies lack consistency in defining AKI. Available RCTs are underpowered to detect a difference in AKI requiring RRT; evidence from observational studies suggests a reduction in RRT requirement. Future studies should apply a standard definition of AKI and target a high-risk population.

Minimal extracorporeal circulation: an alternative for on-pump and off-pump coronary revascularization

BACKGROUND

Coronary artery bypass surgery employing minimal extracorporeal circulation (MECC) was compared with standard extracorporeal circulation (ECC) and off-pump coronary artery bypass graft surgery (OPCABG) with regard to the perioperative course.

METHODS

From January 2004 to December 2007, 1,674 patients (n = 558 MECC, n = 558 ECC, n = 558 OPCABG) who underwent coronary bypass surgery were studied. The primary end point was in-hospital mortality; secondary end points were perioperative variables, intensive care, and in-hospital course.

RESULTS

Demographic data, comorbidity, and the European System for Cardiac Operative Risk Evaluation score (MECC 3.0%, ECC 3.5%, OPCABG 3.2%) were similar among the groups, but in-hospital mortality for elective and urgent/emergent patients was lower in the MECC and OPCABG groups (MECC 3.2%, OPCABG 3.7%, ECC 6.9%; p < 0.05). The number of distal anastomoses was lowest in the OPCABG group, but comparable for MECC and ECC patients. Postoperative ventilation time, release of creatinine kinase, catecholamine therapy, drainage loss, and transfusion requirements were lower in the MECC and OPCABG groups, whereas stay in the intensive care unit was shorter only in the latter (p < 0.05).

CONCLUSIONS

Minimal extracorporeal circulation is an easy and safe procedure for coronary artery bypass graft surgery. In selected patients, the advantages of MECC equal those of OPCABG. MECC should be considered as an alternative to OPCABG and standard ECC procedures.

Higher IL-6 levels but not IL6 -174G>C or -572G>C genotype are associated with post-operative complication following coronary artery bypass graft (CABG) surgery

Large increases in inflammatory markers, particularly IL-6, occur after cardiac surgery. However, despite interventions to reduce the inflammatory response, great variability still remains which could in part be attributable to genetic predisposition. Since increased IL-6 levels following surgery are also associated with poorer outcome we sought to determine whether baseline and post-operative levels of Interleukin-6 (IL-6) and functional common variants of the Interleukin-6 (IL6) gene are associated with post-operative outcome following coronary artery bypass grafting (CABG). Caucasian patients undergoing first-time elective CABG were studied. IL-6 levels were measured pre-, 6h and 24h following surgery and genotypes for IL6 gene variants -174G>C and -572G>C were obtained. Clinical data was collected daily until patient discharge. Patient outcome was categorised as with (ICUC, n=177) and without (NICUC, n=189) a post-operative complication during the ICU period and with (POC, n=215) and without (NC, n=151) a post-operative complication during hospitalisation. IL-6 levels pre- and at 24h were greater in POC and ICUC than NC and NICUC, respectively. Pre- IL-6 levels independently predicted (for 1 standard deviation increase in log IL-6) POC (OR 1.4, 95% CI 1.1-1.7, p=0.008) and ICUC (OR 1.3, 95% CI 1.0-1.6, p=0.02) outcomes. Overall, the IL6-572G>C had an effect over time on IL-6 levels (p=0.04) and on IL-6 levels in NC (P=0.008) and NICUC (p=0.006). However, no associations were found with the IL6 -572G>C or -174G>C variants on IL-6 levels at individual time-points or by outcome group. Thus, in conclusion, elevated pre-operative IL-6 levels, but not IL6 gene variants predict poor patient outcome following CABG.

Cardiac surgery as a cause of acute kidney injury: pathogenesis and potential therapies

Cardiopulmonary bypass surgery occurs in nearly 1 million patients per year. Acute kidney injury requiring dialysis can occur in up to 1% of these patients. The development of acute kidney injury is associated with substantial morbidity and mortality independent of all other factors, and many patients are left dependent on dialysis therapies. The pathogenesis of acute kidney injury involves multiple pathways. Hemodynamic, inflammatory, and nephrotoxic factors are involved and overlap each other in leading to kidney injury. Clinical studies have identified risk factors for acute kidney injury that can be used to effectively determine the risk of acute kidney injury in patients undergoing bypass surgery. These high-risk patients can then be targeted for renal protective strategies. Thus far, no single strategy has conclusively demonstrated its ability to prevent renal injury post-bypass surgery. Novel anti-inflammatory agents are in development and offer hope as potential therapies.

Inflammatory and Hemostatic Activation in Patients Undergoing Off-Pump Coronary Artery Bypass Grafting

To characterize hemostatic differences imposed by 2 common cardiac surgeries, the authors studied patients undergoing coronary artery revascularization by off-pump (n = 13) or cardiopulmonary bypass on-pump (n = 26) technique. Blood samples collected to 4 days post-surgery were evaluated by flow cytometry and enzyme-linked immunosorbent assay. A significant inflammatory response occurred in both the groups after surgery shown by increased interleukin cytokines and C-reactive protein; however, levels peaked lower and hours later in the off-pump group. Platelets (P-selectin; platelet-leukocyte complexes) and leukocytes (CD11b) were activated only in on-pump patients. Thrombin generation was enhanced in both groups after surgery. Only in the on-pump patients, the thrombin-antithrombin complex, pro-thrombin fragment 1.2, and thrombomodulin (vascular integrity) decreased intraoperatively. Tissue plasminogen activator and plasminogen activator inhibitor-1 were greater in the on-pump patients. Off-pump surgery may place patients at higher risk of postoperative hypercoagulability because of normal platelet function, intraoperative thrombin generation, less fibrinolytic activity, and lack of vascular protection.