Retrograde cardioplegia preserves myocardial function after induced coronary air embolism

AbstractCoronary air embolism is a potential complication of cardiopulmonary bypass. We compared left ventricular function before and after the administration of antegrade or retrograde cardioplegic solution in a porcine model of coronary air embolism. Nineteen pigs were placed on cardiopulmonary bypass support and cooled to 32° C. The heart was initially arrested with antegrade cold blood cardioplegic solution. The aortic crossclamp was released at 30 minutes and 0.02 cc/kg body weight of air was injected into the left anterior descending artery distal to the first diagonal branch. After 5 minutes the aorta was reclamped and the animals treated with 15 ml/kg body weight of 1:4 blood cardioplegic solution delivered by the antegrade (n = 6) or retrograde (n = 7) method. Control animals (n = 6) were not treated. Changes in regional preload recruitable stroke work were used to assess left ventricular performance before and after cardiopulmonary bypass. Two control animals could not be weaned from cardiopulmonary bypass. Left ventricular function was best preserved after treatment of induced coronary air embolism with retrograde cardioplegia (90% of baseline). Coronary air embolism treatment with antegrade cardioplegia resulted in diminished left ventricular performance (68% of baseline). In control animals left ventricular contractility was significantly impaired (39% of baseline). We conclude that administration of retrograde cardioplegic solution may be an effective method of treating coronary air embolism. The favorable outcome seen with cardioplegia may be in part because of its ability to protect the ischemic myocardium while the solution mechanically dislodges air from the vascular bed. (J Thorac Cardiovasc Surg 1997;113:917-22

Hyperglycaemia, ejection fraction and the risk of heart failure or cardiovascular death in patients with type 2 diabetes and a recent acute coronary syndrome

Aims: Chronic hyperglycaemia, assessed by elevated glycated haemoglobin (A1C), is a known risk factor for heart failure (HF) and cardiovascular (CV) death among subjects with diabetes. Whether this risk varies with left ventricular ejection fraction (LVEF) is unknown. This study evaluated whether A1C influences a composite outcome of either HF hospitalization or CV death differently along the spectrum of LVEF. Methods and results: We assessed the relationships of baseline A1C and LVEF with a composite outcome of either CV death or HF hospitalization in the 4091 patients with type 2 diabetes and a recent acute coronary syndrome enrolled in the ELIXA trial who had available LVEF. We assessed for interaction between A1C and LVEF as continuous variables with respect to this outcome. During a median follow‐up of 25.7 months, 343 patients (8.4%) had HF hospitalization or died of CV causes. In a multivariable model, A1C and LVEF were each associated with an increased risk of HF hospitalization or CV death [adjusted hazard ratio (HR) 1.11, 95% confidence interval (CI) 1.01–1.21 per 1% higher A1C, and adjusted HR 1.39, 95% CI 1.27–1.51 per 10% lower in LVEF]. Both A1C and LVEF were independently and incrementally associated with risk without evidence of interaction (P for interaction = 0.31). Patients with A1C ≥ 8% and LVEF <40% were at threefold higher risk than those with A1C < 7% and LVEF ≥50% (adjusted HR 3.18, 95% CI 2.03–4.98, P < 0.001). Conclusion: In a contemporary cohort of patients with type 2 diabetes and acute coronary syndrome, baseline chronic hyperglycaemia was associated with an increased risk of HF hospitalization or CV death independently of LVEF

Predicting stroke in heart failure and reduced ejection fraction without atrial fibrillation

Background and Aims: Patients with heart failure with reduced ejection fraction (HFrEF) are at significant risk of stroke. Anticoagulation reduces this risk in patients with and without atrial fibrillation (AF), but the risk-to-benefit balance in the latter group, overall, is not favourable. Identification of patients with HFrEF, without AF, at the highest risk of stroke may allow targeted and safer use of prophylactic anticoagulant therapy. Methods: In a pooled patient-level cohort of the PARADIGM-HF, ATMOSPHERE, and DAPA-HF trials, a previously derived simple risk model for stroke, consisting of three variables (history of prior stroke, insulin-treated diabetes, and plasma N-terminal pro-B-type natriuretic peptide level), was validated. Results: Of the 20,159 patients included, 12,751 patients did not have AF at baseline. Among patients without AF, 346 (2.7%) experienced a stroke over a median follow-up of 2.0 years (rate 11.7 per 1000 patient-years). The risk for stroke increased with increasing risk score: fourth quintile HR 2.35 (95%CI 1.60-3.45); fifth quintile HR 3.73 (2.58-5.38), with the first quintile as reference. For patients in the top quintile, the rate of stroke was 21.2 per 1000 patient-years, similar to participants with AF not receiving anticoagulation (20.1 per 1000 patient-years). Model discrimination was good with a C-index of 0.84 (0.75-0.91). Conclusions: It is possible to identify a subset of HFrEF patients without AF with a stroke risk equivalent to that of patients with AF who are not anticoagulated. In these patients, the risk-to-benefit balance might justify the use of prophylactic anticoagulation, but this hypothesis needs to be tested prospectively

Mitral valve surgery for mitral regurgitation caused by Libman-Sacks endocarditis: a report of four cases and a systematic review of the literature

Libman-Sacks endocarditis of the mitral valve was first described by Libman and Sacks in 1924. Currently, the sterile verrucous vegetative lesions seen in Libman-Sacks endocarditis are regarded as a cardiac manifestation of both systemic lupus erythematosus (SLE) and the antiphospholipid syndrome (APS). Although typically mild and asymptomatic, complications of Libman-Sacks endocarditis may include superimposed bacterial endocarditis, thromboembolic events, and severe valvular regurgitation and/or stenosis requiring surgery. In this study we report two cases of mitral valve repair and two cases of mitral valve replacement for mitral regurgitation (MR) caused by Libman-Sacks endocarditis. In addition, we provide a systematic review of the English literature on mitral valve surgery for MR caused by Libman-Sacks endocarditis. This report shows that mitral valve repair is feasible and effective in young patients with relatively stable SLE and/or APS and only localized mitral valve abnormalities caused by Libman-Sacks endocarditis. Both clinical and echocardiographic follow-up after repair show excellent mid- and long-term results

Improved functionalization of oleic acid-coated iron oxide nanoparticles for biomedical applications

Superparamagnetic iron oxide nanoparticles can providemultiple benefits for biomedical applications in aqueous environments such asmagnetic separation or magnetic resonance imaging. To increase the colloidal stability and allow subsequent reactions, the introduction of hydrophilic functional groups onto the particles’ surface is essential. During this process, the original coating is exchanged by preferably covalently bonded ligands such as trialkoxysilanes. The duration of the silane exchange reaction, which commonly takes more than 24 h, is an important drawback for this approach. In this paper, we present a novel method, which introduces ultrasonication as an energy source to dramatically accelerate this process, resulting in high-quality waterdispersible nanoparticles around 10 nmin size. To prove the generic character, different functional groups were introduced on the surface including polyethylene glycol chains, carboxylic acid, amine, and thiol groups. Their colloidal stability in various aqueous buffer solutions as well as human plasma and serum was investigated to allow implementation in biomedical and sensing applications.status: publishe

Baseline characteristics of patients in the reduction of events with darbepoetin alfa in heart failure trial (RED-HF)

<p>Aims: This report describes the baseline characteristics of patients in the Reduction of Events with Darbepoetin alfa in Heart Failure trial (RED-HF) which is testing the hypothesis that anaemia correction with darbepoetin alfa will reduce the composite endpoint of death from any cause or hospital admission for worsening heart failure, and improve other outcomes.</p> <p>Methods and results: Key demographic, clinical, and laboratory findings, along with baseline treatment, are reported and compared with those of patients in other recent clinical trials in heart failure. Compared with other recent trials, RED-HF enrolled more elderly [mean age 70 (SD 11.4) years], female (41%), and black (9%) patients. RED-HF patients more often had diabetes (46%) and renal impairment (72% had an estimated glomerular filtration rate <60 mL/min/1.73 m2). Patients in RED-HF had heart failure of longer duration [5.3 (5.4) years], worse NYHA class (35% II, 63% III, and 2% IV), and more signs of congestion. Mean EF was 30% (6.8%). RED-HF patients were well treated at randomization, and pharmacological therapy at baseline was broadly similar to that of other recent trials, taking account of study-specific inclusion/exclusion criteria. Median (interquartile range) haemoglobin at baseline was 112 (106–117) g/L.</p> <p>Conclusion: The anaemic patients enrolled in RED-HF were older, moderately to markedly symptomatic, and had extensive co-morbidity.</p&gt

Protein biomarkers and cardiovascular outcomes in people with type 2 diabetes and acute coronary syndrome: the ELIXA biomarker study

Objective: To use protein biomarkers to identify people with type 2 diabetes at high risk of cardiovascular outcomes and death. Research Design and Methods: Biobanked serum from 4,957 ELIXA (Evaluation of Lixisenatide in Acute Coronary Syndrome) trial participants was analyzed. Forward-selection Cox models identified independent protein risk factors for major adverse cardiovascular events (MACE) and death that were compared with a previously validated biomarker panel. Results: NT-proBNP and osteoprotegerin predicted both outcomes. In addition, trefoil factor 3 predicted MACE, and angiopoietin-2 predicted death (C = 0.70 and 0.79, respectively, compared with 0.63 and 0.66 for clinical variables alone). These proteins had all previously been identified and validated. Notably, C statistics for just NT-proBNP plus clinical risk factors were 0.69 and 0.78 for MACE and death, respectively. Conclusions: NT-proBNP and other proteins independently predict cardiovascular outcomes in people with type 2 diabetes following acute coronary syndrome. Adding other biomarkers only marginally increased NT-proBNP’s prognostic value