Perioperative cardiovascular system failure in South Asians undergoing cardiopulmonary bypass is associated with prolonged inflammation and increased Toll-like receptor signaling in inflammatory monocytes

Background

South Asian ethnicity is an independent risk factor for mortality after coronary artery bypass. We tested the hypothesis that this risk results from a greater inflammatory response to cardiopulmonary bypass (CPB).

Methods

This was a single-site prospective cohort study. We compared the inflammatory response to CPB in 20 Caucasians and 17 South Asians undergoing isolated coronary artery bypass grafting surgery.

Results

Plasma levels of proinflammatory cytokines (interleukin [IL]-6, IL-8, IL-12, interferon gamma, and tumor necrosis factor) and anti-inflammatory mediators (IL-10 and soluble TNF receptor I) were measured. The Toll-like receptor (TLR) signaling pathway was examined in peripheral blood monocytes by flow cytometry, measuring surface expression of TLR2, TLR4, and coreceptor CD14 and activation of downstream messenger molecules (interleukin-1 receptor-associated kinase 4, nuclear factor kappa from B cells (NF-κB), c-Jun amino-terminal kinase, p38 mitogen-activated protein kinase, and Protein Kinase B). South Asians had persistently higher plasma levels of IL-6 and exhibited increased TLR signaling through the p38 mitogen-activated protein kinase and Protein Kinase B pathways in inflammatory monocytes after CPB. This increased inflammatory response was paralleled clinically by a higher sequential organ failure assessment score (5.1 ± 1.4 versus 1.5 ± 1.6, P = 0.027) and prolonged cardiovascular system failure (23.5% versus 0%) 48 h after CPB.

Conclusions

South Asians develop an exacerbated systemic inflammatory response after CPB, which may contribute to the higher morbidity and mortality associated with coronary artery bypass in this population. These patients may benefit from targeted anti-inflammatory therapies designed to mitigate the adverse consequences resulting from this response.     

Tachycardia mediated cardiomyopathy: Pathophysiology,mechanisms, clinical features and management

Tachycardia mediated cardiomyopathy (TMC) is a reversible form of dilated cardiomyopathy that can occur with most supraventricular and ventricular arrhythmias. Despite the plethora of literature describing this entity in animal models, as well as humans, it remains poorly understood. Over the last decade, new etiologies of TMC, such as frequent premature ventricular complexes in normal hearts, have been identified. Recent advances in catheter-based ablation therapies, particularly for atrial fibrillation and ventricular arrhythmias, have added a new dimension to the treatment of this condition. This review describes the pathophysiology, proposed mechanisms, clinical features and management in various arrhythmic conditions.     

Carotid intima-media thickness in children with Kawasaki disease

Kawasaki disease (KD) is an acute medium vessel vasculitis seen in children. The most significant long-term complication is related to coronary artery abnormalities. Use of intravenous immunoglobulins, however, has led to significant reduction in incidence of coronary aneurysms. What is more alarming is the fact that higher risk of cardiovascular disease is seen in even those children who do not have coronary artery aneurysms during subacute phase. Various factors like abnormal lipid profiles, abnormal vessel wall reactivity and endothelial dysfunction have been implicated for this. Carotid intima-media thickness (cIMT) has been used as a surrogate marker for atherosclerosis. This study was planned to evaluate cIMT in children with KD. Twenty-seven children with diagnosis of KD at least 1 year prior to enrolment were evaluated for cIMT at enrolment and then after 3 months. Fasting lipid profile was done for all patients. Mean cIMT was significantly higher in children with KD compared to controls. In lipid profiles, undesirable HDL-C and triglyceride levels were seen in 2 and 3 children, respectively. Undesirable and borderline LDL-C levels were seen in 1 and 2 patients, respectively. Undesirable and borderline total cholesterol levels were seen in 1 and 3 patients, respectively. Higher cIMTs were seen in our cohort of KD patients. Proatherogenic abnormalities in lipid profile were seen in a few patients. Both abnormalities may predict a higher risk of atherosclerosis in future. The results of this study need to be replicated on a larger study sample and over longer follow-up periods.     

Efficacy of Withania somnifera chemotypes NMITLI – 101R, 118R and Withaferin A against experimental visceral leishmaniasis

The immunoprophylactic and therapeutic potentials of root extracts of Withania somnifera chemotypes (NMITLI‐118, NMITLI‐101) and pure withanolide–withaferin A was investigated against Leishmania donovani infection in hamsters. The naive animals, fed orally with immunostimulatory doses of chemotypes 101R, 118R (10 and 3 mg/kg) and withaferin A (9 and 3 mg/kg) for five consecutive days and challenged with Leishmania parasites on day 6, were euthanized on days 30 and 45 p.c. for the assessment of parasite clearance, real‐time analysis of mRNAs of Th1/Th2 cytokines (IFN‐γ, IL‐12, TNF‐α, iNOS/IL‐4, IL‐10 and TGF‐β), NO production, reactive oxygen species (ROS) generation, lymphocyte transformation test and antibody responses. By day 45 p.c., there was a significant increase in the mRNA expression of iNOS, IFN‐γ, IL‐12 and TNF‐α but decrease in IL‐4, IL‐10 and TGF‐β, an enhanced Leishmania‐specific LTT response as well as ROS, NO and antileishmanial IgG2 levels in 101R‐treated hamsters followed by 118R‐ and withaferin A‐treated ones, respectively. When these chemotypes were given to L. donovani‐infected hamsters at different doses, there was moderate therapeutic efficacy of chemotype 101R (~50%) at 30 mg/kg × 5 followed by the other two. The results established that the 101R is the most potential chemotype and can be evaluated for combination therapy along with available antileishmanials.