Randomized Pilot Trial of Pre- and Postoperative Heart Failure Nurse-Supported Care in Heart Failure Patients Requiring Noncardiac Surgery-Feasibility and Results.

INTRODUCTION: The perioperative cardiovascular management of patients undergoing noncardiac surgery is particularly challenging in those with pre-existing heart failure (HF). This study was designed to evaluate the effectiveness of nurse-based pre- and postoperative specialized HF management in reducing postoperative HF-associated complications in patients with known HF undergoing noncardiac surgery. METHODS: This prospective, randomized pilot study included patients with established HF requiring intermediate- to high-risk noncardiac surgery. Patients received postoperatively either standard care (control group, CG) or nurse-supported HF management (intervention group, IG). The primary endpoint was a composite of HF-related postoperative complications at 30 days. Secondary endpoints included length on intensive care unit, length of hospital stay, death, hospitalization for HF, and quality of life assessment using the SF-12 questionnaire. RESULTS: The trial was halted prematurely for futility. A total of 34 patients (median age 70.5 [IQR 67-75] years; with 15 HfpEF, 9 HfmrEF,10 HfrEF), with an average NT-proBNP of 1.413 [463-2.832] pg/mL were included. The IG had a lower rate of postoperative primary events (25%; n = 4) compared with the CG (33%; n = 6). There were no differences in secondary endpoints between the groups. Quality-of-life scores improved slightly in both groups (δ 5.6 ± 0.9 [CG] and 3.1 ± 1.2 [IG]). CONCLUSION: Nurse-based pre- and postoperative HF care appears to be feasible and may reduce HF-associated complications in patients undergoing noncardiac surgery. Larger clinical trials are needed to further evaluate the effectiveness of this approach in reducing postoperative complications in this high-risk patient population.

Metal allergens nickel and cobalt facilitate TLR4 homodimerization independently of MD2.

Development of contact allergy requires cooperation of adaptive and innate immunity. Ni(2+) stimulates innate immunity via TLR4/MD2, the bacterial LPS receptor. This likely involves receptor dimerization, but direct proof is pending and it is unclear if related haptens share this mechanism. We reveal Co(2+) as second metal stimulating TLR4 and confirm necessity of H456/H458 therein. Experiments with a new TLR4 dimerization mutant established dimerization as a mechanism of metal- and LPS-induced TLR4 activation. Yet, in interaction studies only LPS- but not metal-induced dimerization required MD2. Consistently, soluble TLR4 expressed without MD2 inhibited metal- but not LPS-induced responses, opening new therapeutic perspectives.

Crucial role for human Toll-like receptor 4 in the development of contact allergy to nickel.

Allergies to nickel (Ni(2+)) are the most frequent cause of contact hypersensitivity (CHS) in industrialized countries. The efficient development of CHS requires both a T lymphocyte-specific signal and a proinflammatory signal. Here we show that Ni(2+) triggered an inflammatory response by directly activating human Toll-like receptor 4 (TLR4). Ni(2+)-induced TLR4 activation was species-specific, as mouse TLR4 could not generate this response. Studies with mutant TLR4 proteins revealed that the non-conserved histidines 456 and 458 of human TLR4 are required for activation by Ni(2+) but not by the natural ligand lipopolysaccharide. Accordingly, transgenic expression of human TLR4 in TLR4-deficient mice allowed efficient sensitization to Ni(2+) and elicitation of CHS. Our data implicate site-specific human TLR4 inhibition as a potential strategy for therapeutic intervention in CHS that would not affect vital immune responses.

The contact allergen nickel sensitizes primary human endothelial cells and keratinocytes to TRAIL-mediated apoptosis.

Primary endothelial cells are fully resistant to TNF-related apoptosis-inducing ligand (TRAIL)-mediated apoptosis. Here, we demonstrate that certain environmental conditions, such as exposure to the widespread allergen nickel, can dramatically increase the susceptibility of naturally resistant primary endothelial cells or keratinocytes to TRAIL-induced apoptosis. While nickel treatment increased surface expression of the apoptosis-inducing TRAIL receptors TRAIL-R1 and TRAIL-R2, it also up-regulated the apoptosis-deficient TRAIL-R4, suggesting that modulation of TRAIL receptor expression alone is unlikely to fully account for the dramatic sensitization effect of nickel. Further analysis of candidate mediators revealed that nickel strongly repressed c-FLIP at mRNA and protein levels. Accordingly, increased activation of Caspase-8 and Caspase-3 following nickel treatment was observed. Importantly, depletion of c-FLIP by RNA interference could largely recapitulate the effect of nickel and sensitize endothelial cells to TRAIL-dependent apoptosis in the absence of nickel pre-treatment. Conversely, ectopic expression of c-FLIP(L) largely protected nickel-treated cells from TRAIL-mediated apoptosis. Our data demonstrate that one key mechanism of sensitization of primary human endothelial cells or keratinocytes is transcriptional down-regulation of c-FLIP. We hypothesize that environmental factors, exemplified by the contact allergen nickel, strongly modulate death ligand sensitivity of endothelial cells and keratinocytes thus influencing vascular and epidermal function and integrity under physiological and pathophysiological conditions.