Blood and urinary cytokine balance and renal outcomes at cardiac surgery

BACKGROUND

Increased perioperative pro-inflammatory biomarkers, renal hypoperfusion and ischemia reperfusion injury (IRI) heighten cardiac surgery acute kidney injury (CS-AKI) risk. Increased urinary anti-inflammatory cytokines attenuate risk. We evaluated whether blood and urinary anti-inflammatory biomarkers, when expressed as ratios with biomarkers of inflammation, hypoperfusion and IRI are increased in CS-AKI patients.

METHODS

Preoperative and 24-h postoperative blood and urinary pro-inflammatory and anti-inflammatory cytokines, blood VEGF and H-FABP (hypoperfusion biomarkers), and MK, a biomarker for IRI, were measured in 401 cardiac surgery patients. Pre- and postoperative concentrations of biomarkers and selected ratios thereof, were compared between non-CS-AKI and CS-AKI patients.

RESULTS

Compared with non-CS-AKI, blood pro-inflammatory (pre- and post-op TNFα, IP-10, IL-12p40, MIP-1α, NGAL; pre-op IL-6; post-op IL-8, MK) and anti-inflammatory (pre- and post-op sTNFsr1, sTNFsr2, IL-1RA) biomarkers together with urinary pro-inflammatory (pre- and post-op uIL-12p40; post-op uIP-10, uNGAL) and anti-inflammatory (pre- and post-op usTNFsr1, usTNFsr2, uIL-1RA) biomarkers, were significantly higher in CS-AKI patients. Urinary anti-inflammatory biomarkers, when expressed as ratios with biomarkers of inflammation (blood and urine), hypoperfusion (blood H-FABP and VEGF) and IRI (blood MK) were decreased in CS-AKI. In contrast, blood anti-inflammatory biomarkers expressed as similar ratios with blood biomarkers were increased in CS-AKI.

CONCLUSIONS

The urinary anti-inflammatory response may protect against the injurious effects of perioperative inflammation, hypoperfusion and IRI. These finding may have clinical utility in bioprediction and earlier diagnosis of CS-AKI and informing future therapeutic strategies for CS-AKI patients.

Outcomes of off-pump coronary artery bypass grafting in non-dialysis-dependent patients with stage 2 and stage 3 chronic kidney disease

Purpose

To assess the short-term outcomes in non-dialysis-dependent patients with stage 2 and stage 3 chronic kidney disease (CKD), undergoing off-pump coronary artery bypass (OPCAB). To examine whether there was a difference in mortality between stage 2 and stage 3 CKD patients and whether mortality in diabetics was different compared to non-diabetics. Outcomes would be judged on the basis of possible cardiovascular, pulmonary, infective, neurological and renal complications, duration of stay at the intensive therapy unit (ITU), and overall duration of stay at the hospital. A comparative study of outcomes between stage 2 and stage 3 CKD would be undertaken. Also, given the impact of diabetes mellitus in this patient population, a comparative study of outcomes would be made between diabetics and non-diabetics.

Methods

Three hundred fifteen consecutive patients undergoing OPCAB were included in this observational prospective study. Of them, 201 (64%) had stage 3 CKD and 114 (36%) had stage 2 CKD. Nearly half of the study group (49.52%) were diabetics. Data was collected from patients' files, patient observation charts at the ITU, and patient interviews. Continuous variables were expressed as mean ± standard deviation or median (Q1, Q3) as appropriate and qualitative variables presented with the frequency and corresponding percentage. Comparison between diabetic and non-diabetic patients was performed by the Student's t test or chi-square test as appropriate. And when assumptions of parametric test failed, then an appropriate non-parametric test was performed. Repeated measures ANOVA (analysis of variance) was used to see the trend of estimated glomerular filtration rate (eGFR) values. Statistical analysis was done by using SPSS version 19.0 (SPSS Inc., Chicago, IL, USA). All p values <0.05 were considered statistically significant.

Results

The eGFR was measured pre-operatively, on the day following OPCAB and at the time of discharge and the mean eGFR, remained more or less the same throughout (mean of 55.86 ml/min/1.73 m² pre-operatively, 58.39 ml/min/1.73 m² on the day following OPCAB and 58.39 ml/min/1.73 m² at discharge). One patient with stage 2 CKD (0.9%) required hemodialysis post-operatively while 3 patients (1.5%) required the same in the stage 3 CKD group, which was not statistically significant. Nineteen patients (6.03%) required re-intubation for hypoxia in the post-operative period. Post-operative myocardial infarction developed in 12 patients (3.81%). Twenty patients (6.35%) patients needed an intra-aortic balloon pump (IABP) insertion in the peri-operative period owing to hemodynamic compromise. Fifteen patients (4.76%) were re-explored for bleeding following surgery and fifteen patients (4.76%) had a deep sternal wound infection in the post-operative period. New-onset atrial fibrillation was found to be present in 42 stage 3 CKD patients (11%) while it occurred in 21 stage 2 CKD patients (9.6%) (p value = 0.014), which was statistically significant. The mean duration of ITU stay was 84 ± 6.22 h in the stage 2 CKD group and 92.9 ± 8.18 h in the stage 3 CKD group (p value = 0.01), which was statistically significant. Mean duration of ITU stay was 94 ± 10.12 h in the diabetic group while it was 86.7 ± 11.08 h in the non-diabetic group (p value = 0.008) which was statistically significant. Duration of post-operative hospital stay was a mean of 8 ±0.08 days in the diabetic group whereas it was 7 ± 0.04 days in the non-diabetic group (p value = 0.012), which was statistically significant. Surgical mortality was 6 out of 315 patients (1.9%).

Conclusion

OPCAB is a safe and effective revascularization strategy in patients with stage 2 and stage 3 CKD. Short-term outcomes of OPCAB have been good in the patient population in this study, in terms of both surgical morbidity and mortality. Surgical mortality was 1.9%. New-onset atrial fibrillation was found in eleven patients (9.6%) in the stage 2 CKD group and 42 patients (21%) in the stage 3 CKD group (p value =0.014) which was statistically significant. The results of this study reflect the reno-protective nature of OPCAB. The duration of ITU stay and the post-operative duration of stay at the hospital were found to be significantly more in diabetics than in non-diabetics.

Coronary revascularization in the elderly with stable angina

A proportion of elderly with coronary artery disease is rapidly growing. They have more severe coronary artery disease, therefore, derive more benefit from revascularization and have a greater need for it. The elderly is a heterogeneous group, but compared to the younger cohort, the choice of the optimal revascularization method is much more complicated among them. In recent decades, results has improved dramatically both in surgery and percutaneous coronary intervention (PCI), even in very old persons. Despite the lack of evidence in elderly, it is obvious, that coronary artery bypass surgery (CABG) has a more pronounced effect on long-term survival in price of more strokes, while PCI is certainly less invasive. Age itself is not a criterion for the selection of treatment strategy, but the elderly are often more interested in quality of life and personal independence instead of longevity. This article discusses the factors that influence the choice of the revascularization method in the elderly with stable angina and presents a complex algorithm for making an individual risk-benefit profile. As a consequence the features of CABG and PCI in elderly patients are exposed. Emphasis is centered on the frailty and non-medical factors, including psychosocial, as essential components in making the decision of what strategy to choose. Good communication with the patients and giving them unbiased information is encouraged.

Cytokine phenotype, genotype, and renal outcomes at cardiac surgery

BACKGROUND

Cardiac surgery modulates pro- and anti-inflammatory cytokine balance involving plasma tumour necrosis factor alpha (TNFα) and interleukin-10 (IL-10) together with urinary transforming growth factor beta-1 (TGFβ1), interleukin-1 receptor antagonist (IL1ra) and tumour necrosis factor soluble receptor-2 (TNFsr2). Effects on post-operative renal function are unclear. We investigated if following cardiac surgery there is a relationship between cytokine (a) phenotype and renal outcome; (b) genotype and phenotype and (c) genotype and renal outcome. Since angiotensin-2 (AG2), modulates TGFβ1 production, we determined whether angiotensin converting enzyme insertion/deletion (ACE I/D) genotype affects urinary TGFβ1 phenotype as well as renal outcome.

METHODS

In 408 elective cardiac surgery patients we measured pre- and 24 h post-operative urinary TGFβ-1, IL1ra and TNFsr2 and pre- and 2 h post-operative plasma TNFα and IL-10. Post-operative responses were compared for each cytokine in patients grouped according to presence or absence of renal dysfunction defined as a drop from baseline eGFR of greater than 25% (as calculated by the method of modification of diet in renal disease (MDRD)) occurring (1) within the first 24 and (2) 48 postoperative hours (early renal dysfunction), (3) on the fifth postoperative day (late renal dysfunction) or (4) at any time throughout the 5 day postoperative period (early and late combined). Patient genotype was determined for TNF/G-308A, TGFβ1-509 C/T, IL10/G-1082A and ACE I/D.

RESULTS

Post-operative plasma IL-10 and urinary TGFβ1 responses were significantly higher in patients who developed early renal dysfunction. IL1ra and TNFsr2 responses were significantly lower 24h post-operatively in patients who developed late renal dysfunction. Genotype did not alter cytokine phenotype or outcome. CONCLUSIONS/INFERENCES: Cytokine profiling may help predict early and late renal dysfunction. Genotypes studied did not alter phenotype or outcome.

Impact of preoperative renal dysfunction on outcomes of off-pump coronary artery bypass grafting

BACKGROUND

This study assessed whether preoperative renal insufficiency predisposes patients undergoing off-pump coronary artery revascularization to postoperative dialysis.

METHODS

From August 2004 through June 2009, 2,275 patients undergoing off-pump coronary artery bypass were categorized into five groups (stages) by glomerular filtration rate (GFR). Of these, 1,855 patients had renal insufficiency: stage 2: 1,406; stage 3: 428; stage 4: 21, and 414 had normal renal function, stage 1. Excluded were 6 patients with end-stage renal disease (stage 5). Preoperative variables and postoperative outcomes were compared among groups.

RESULTS

Preoperative patient characteristics were similar; however, patients with normal renal function were younger (p = 0.001). Serum creatinine rose significantly above baseline on the first postoperative day in the renal insufficiency groups (p = 0.001). The GFR groups had similar inotrope use, reexploration rate, duration of postoperative mechanical ventilation, postoperative stroke, wound infection, and mortality rate. Stage 4 patients had a higher incidence of postoperative myocardial infarction (p = 0.002). Stage 3 and 4 patients had an increased need for postoperative dialysis vs stage 1 patients (p = 0.002).

CONCLUSIONS

Nonparametric contingency analysis showed patients with low preoperative GFR (stage 3 and 4, p < 0.0001) and a history of smoking (p = 0.04) were at increased risk for postoperative dialysis. Patients who required postoperative inotropic support tended toward requiring postoperative dialysis (p = 0.06). Low preoperative ejection fraction (p = 0.83), class III or IV angina (p = 0.069), and postoperative blood transfusions were not associated with the need for postoperative dialysis in patients undergoing off-pump revascularization.

Different treatment options in chronic coronary artery disease: when is it the time for medical treatment, percutaneous coronary intervention or aortocoronary bypass surgery?

BACKGROUND

3% to 4% of the population suffers from chronic coronary artery disease (CAD). Primary care physicians, internists, cardiologists, and cardiac surgeons are involved in their long-term care. This article presents a complementary care pathway that integrates two apparently competing treatment options, aortocoronary bypass surgery (ACB) and percutaneous coronary intervention (PCI). Together with lifestyle changes and medical therapy, these treatments reduce morbidity and mortality and improve quality of life.

METHODS

This article was written by cardiac surgeons and cardiologists on the basis of the current treatment guidelines for coronary artery disease, a selective review of the literature (randomized, controlled trials and registry data), and a process of interdisciplinary consensus building.

RESULTS AND CONCLUSIONS

Lifestyle changes can reduce cardiovascular risk factors, improve quality of life, and lower cardiovascular morbidity and mortality. They provide additional benefit over and above medical therapy and/or revascularization procedures and should be strongly recommended to all patients. Revascularization is not indicated for patients who are asymptomatic on medical therapy or who have only a small area of myocardial ischemia. With either PCI or ACB, the symptoms of angina pectoris can be markedly improved, or even eliminated. Both of these revascularization procedures should be accompanied by optimized medical treatment. Revascularization is indicated when the area of myocardial ischemia is large, whether or not symptomatic angina is present. ACB is the treatment of choice for 3-vessel disease and/or left main stenosis. For all other constellations of coronary findings, ACB and PCI are equally good therapeutic options. The treating physician should take the patient's expectations into account and present the short- and long-term benefits and drawbacks of each proposed treatment to the patient so that an informed decision can be made.

Leukocyte-Aprotinin Atrial Fibrillation Study (LAFFS): Impact of Aprotinin and Leukofiltration on Atrial Fibrillation, Renal Insufficiency and Encephalopathy Post-Cardiopulmonary Bypass

Purpose: Atrial fibrillation remains the leading postoperative complication following cardiopulmonary bypass. A randomized trial was undertaken to evaluate the effectiveness of leukocyte filtration and aprotinin, applied separately and in combination, on the incidence of post-operative atrial fibrillation. A secondary component of the study was the impact of these adjunct interventions on post-surgical renal and neurological dysfunction. Methods: A total of 1,220 patients undergoing primary isolated coronary artery bypass grafting were randomly assigned to one of four treatment groups. The control group (305 patients) received standard cardiopulmonary bypass with moderately hypothermic (34ºC) cardioplegic arrest. In the filtration group (310 patients) leukocyte reducing filters were incorporated into the bypass circuit and deployed strategically. The aprotinin group (285 patients) received full Hammersmith dose aprotinin. The combination therapy group (320 patients) received both aprotinin and leukocyte filtration. Results: The incidences of atrial fibrillation were 25% in the control group, 16% in the filtration group, 19% in the aprotinin group and 10% in the combination therapy group (P < 0.001). Renal dysfunction was detected in 3% of the control group, 2% of the filtration group, 8% of the aprotinin group, and 5% of the combination group (P < 0.005). Neurological dysfunction occurred in 2% of the control group, 2% of the filtration group, 1% of the aprotinin group, and 2% of the combination group (P = n.s.). Conclusions: Combination therapy with aprotinin and leukocyte filtration markedly reduced atrial fibrillation post-cardiopulmonary bypass, and was more effective than the individual treatments. Aprotinin treatment increased the incidence of renal dysfunction, and the addition of leukocyte filtration partially mitigated this detrimental effect of aprotinin. Thus, strategic leukocyte filtration augments aprotinin's anti-arrhythmic effects while suppressing its nephrotoxic sequelae.