Preoperative biomarker evaluation for the prediction of cardiovascular events after major vascular surgery.

OBJECTIVE: The cause of perioperative myocardial infarction (PMI) is postulated to involve hemodynamic stress or coronary plaque destabilization. We aimed to evaluate perioperative factors in patients with peripheral artery disease (PAD) undergoing major vascular surgery to determine the likely mechanisms and predictors of PMI. METHODS: This was a prospective cohort study of 133 patients undergoing major vascular surgery including open abdominal aortic aneurysm (AAA) repair (n = 40) and major suprainguinal or infrainguinal arterial bypasses (non-AAA; n = 93). Preoperative assessment with history, physical examination, and peripheral artery tonometry was performed in addition to plasma sampling of biomarkers associated with inflammation and coronary plaque instability. The primary outcome was occurrence of a 30-day cardiovascular event (CVE; composite of PMI [troponin I elevation >99th percentile reference of ≥0.1 µg/L], stroke, or death). RESULTS: Of 133 patients, 36 patients (27%) developed a 30-day CVE after vascular surgery, and all were PMI. Patients with 30-day CVE were older (75 ± 8 years vs 69 ± 10 years, mean ± standard deviation; P = .001), had higher prevalence of hypertension (94% vs 79%; P = .01) and preoperative beta-blocker therapy (50% vs 29%; P = .02), and had longer duration of surgery (5.1 ± 1.8 hours vs 4.0 ± 1.1 hours; P < .0001). Significant elevations in cystatin C, N-terminal pro-B-type natriuretic peptide (NT-proBNP), troponin I, high-sensitivity troponin T, matrix metalloproteinase 3, and osteoprotegerin occurred in those who developed 30-day CVE (all P < .05). Multivariate binary logistic regression identified AAA surgery and log-transformed NT-proBNP to be independent preoperative predictors of 30-day CVE (area under the receiver operating characteristic curve = 0.81). CONCLUSIONS: In patients with peripheral artery disease undergoing major vascular surgery, the likely mechanism of PMI appears to be the hemodynamic stress related to the type and duration of surgery. NT-proBNP was a useful independent predictor of CVE and thus may serve as an important biomarker of cardiovascular fitness for surgery.

The effect of spontaneous curvature on a two-phase vesicle.

Vesicles are membrane-bound structures commonly known for their roles in cellular transport and the shape of a vesicle is determined by its surrounding membrane (lipid bilayer). When the membrane is composed of different lipids, it is natural for the lipids of similar molecular structure to migrate towards one another (via spinodal decomposition), creating a multi-phase vesicle. In this article, we consider a two-phase vesicle model which is driven by nature's propensity to maintain a minimal state of elastic energy. The model assumes a continuum limit, thereby treating the membrane as a closed three-dimensional surface. The main purpose of this study is to reveal the complexity of the Helfrich two-phase vesicle model with non-zero spontaneous curvature and provide further evidence to support the relevance of spontaneous curvature as a modelling parameter. In this paper, we illustrate the complexity of the Helfrich two-phase model by providing multiple examples of undocumented solutions and energy hysteresis. We also investigate the influence of spontaneous curvature on morphological effects and membrane phenomena such as budding and fusion.

Renocaval Bypass for Acute Renal Failure and Haematuria Following Left Renal Vein Ligation During Aorto-Bifemoral Bypass.

Ligation of the left renal vein is an accepted manoeuvre where it is difficult to access the pararenal abdominal aorta for the open treatment of aortic occlusive or aneurysmal disease. There is some controversy regarding the long-term effect of this on renal function. We describe the case of a 37-year-old gentleman who underwent an elective aorto-bifemoral bypass for aorto-iliac occlusive disease with symptoms of short distance claudication, with intra-operative ligation of the left renal vein. This was complicated by post-operative acute renal failure and haematuria, with CT findings of left renal venous dilatation and peri-renal stranding. The patient underwent successful left renocaval bypass with reversed great saphenous vein, with subsequent resolution of haematuria and improvement in renal function. The syndrome of acute renal failure and haematuria is a rare but possible complication of left renal vein ligation during aortic surgery, and restoration of renal venous outflow via renocaval bypass in this instance was an effective method of treating this complication.

Evidence-based smoking cessation interventions for patients with acute respiratory disorders.

Worldwide, tobacco use continues to be the most significant preventable cause of death and hospital admissions, particularly related to respiratory diseases. Acute respiratory illnesses requiring hospitalization provide an opportunity for nurses to intervene and help smokers quit. Of the three top hospital admissions related to respiratory diseases, chronic obstructive pulmonary disease (COPD) is the one that continues to have increased mortality whereas community acquired pneumonia and asthma have decreased over the past 5 years. The course of all three can be caused or exacerbated by continued smoking. This review describes the state of the science of nursing research focused on tobacco cessation interventions for hospitalized patients with COPD, asthma, or community acquired pneumonia. Additionally, we describe two evidence-based, nurse-driven, hospital protocols to treat tobacco dependence that can serve as models of care. Recommendations are made as to how to effectively promote nursing interventions for tobacco cessation in the acute care setting.

Fresh arterial homograft for bypass in critical limb ischaemia with infection.

We present what we believe is Australia's first fresh peripheral arterial transplant for revascularisation of an ischaemic limb. Although cryopreserved homografts are accepted as a management option for revascularisation of critical limb ischaemia in infected fields, cryopreserved peripheral vascular tissue is not currently available in Australia. We describe a 72-year-old man without autologous conduit in whom infected prosthetic grafts were explanted, causing critical limb ischaemia of a below knee stump. Fresh peripheral arterial tissue was procured via the Australian organ donation authority, DonateLife, and was used to revascularise the stump with an axillofemoral bypass. This permitted successful healing of the stump within 6 weeks and mobilisation with a prosthesis. This case illustrates that fresh arterial homografts are a viable bridging solution for revascularisation of limb ischaemia with infection. However, it also highlights the need to establish a peripheral homograft bank so that cryopreserved conduits are readily available for similar scenarios.

Indole-glucosides as novel sodium glucose co-transporter 2 (SGLT2) inhibitors. Part 2.

A series of indole-O-glucosides and C-glucosides was synthesized and evaluated in SGLT1 and SGLT2 cell-based functional assays. Compounds 2a and 2o were identified as potent SGLT2 inhibitors and screened in ZDF rats.

Heteroaryl-O-glucosides as novel sodium glucose co-transporter 2 inhibitors. Part 1.

A series of benzo-fused heteroaryl-O-glucosides was synthesized and evaluated in SGLT1 and 2 cell-based functional assays. Indole-O-glucoside 10a and benzimidazole-O-glucoside 18 exhibited potent in vitro SGLT2 inhibitory activity.

Glycosylated dihydrochalcones as potent and selective sodium glucose co-transporter 2 (SGLT2) inhibitors.

A series of glucose conjugates was synthesized and tested for inhibition of SGLT1 and SGLT2. The core structure was derived from compound 1a. Modification of the benzofuran moiety and 4'-substituent of the phenyl ring in compound 1a improved selectivity at SGLT2. Select compounds were compared to 1a in metabolic stability and in vivo efficacy studies.