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It is unclear whether universal access to primary percutaneous coronary intervention (pPCI) may reduce sex differences in 1-year rehospitalization for heart failure (HF) and myocardial infarction (MI) after ST-elevation myocardial infarction (STEMI). We studied 7,597 consecutive STEMI patients (13.8% women, n = 1,045) who underwent pPCI from January 2007 to December 2013. Cox regression models adjusted for competing risk from death were used to assess sex differences in rehospitalization for HF and MI within 1 year from discharge. Compared with men, women were older (median age 67.6 vs 56.0 years, p0.001) with higher prevalence of co-morbidities and multivessel disease. Women had longer median door-to-balloon time (76 vs 66 minutes, p0.001) and were less likely to receive drug-eluting stents (19.5% vs 24.1%, p = 0.001). Of the medications prescribed at discharge, fewer women received aspirin (95.8% vs 97.6%, p = 0.002) and P2Y

Background Compared with men, women are at increased risk of heart failure hospitalization following acute coronary syndrome (ACS). Purpose We sought to determine whether this increased hazard was associated with differing patterns in left ventricular (LV) remodeling over the first 12 months after ACS. Methods In a prospective multi-centre observational cohort study, 2,140 patients with ACS underwent echocardiography at 1, 4, and 12 months following the index event. Heart failure hospitalisation events were captured over a median 4.8 (IQR 3.4–6.5) years and relative risk compared between women and men using a multivariable Cox model adjusted for baseline demographics (age and systolic blood pressure) and echocardiographic variables (LV end diastolic and end systolic volumes, LV ejection fraction, interventricular septal wall thickness, and E/e') captured at baseline and 12 months. Results The 609 (28.5%) women were older (mean [SD] age 70 [12] versus 65 [12] years), had higher systolic blood pressure, demonstrated smaller increases in peak myocardial biomarkers, and were less likely to undergo coronary revascularization during the index admission (41.9% versus 62.0%; p Conclusions Women experience a more concentric remodeling pattern over the 12 months following ACS. Women remain at increased risk of long-term heart failure hospitalization after accounting for clinical and echocardiographic characteristics. Funding Acknowledgement Type of funding source: Foundation. Main funding source(s): National Heart Foundation of New Zealand, New Zealand Health Research Council

Background Reducing cardiac myocyte (CM) death has been the major focus of cardioprotection in the treatment of myocardial infarction (MI). The post-MI role of cardiac fibroblasts (cFB) has received less attention compared to CM. miRNAs can multi-target in condition-dependent and/or cell type-oriented manner. Reduced miR-211 expression in myocardium is associated with severe cardiac fibrosis in patients with end stage heart failure. We previously reported that miR-221 mimics protect CM in vitro against hypoxic injury. Purpose Taking comprehensive in vivo and in vitro approaches, we tested our hypothesis that miR-221 regulate CM and cFB differently to reduce CM death and inhibit adverse fibrosis following MI. Methods In vitro, H9c2 and rat cFB were transfected with miR-221 mimics (miR-221) and mimic control (MC) and subjected to hypoxia/reperfusion (H/R). Apoptosis (Annexin V and 7-AAD), cell injury (LDH release), and autophagy LC3 II/I and p62 by Western blot (WB). Myofibroblast (myoFB) activation (α-SMA and gel contraction), and collagen synthesis (Sircol assay) were measured. In vivo, following left coronary artery ligation (MI), rats were treated with miR-221 mimics (i.v. 1mg/kg) immediately and 3-days post-MI. Hearts were collected at 2-, 7- and 30-days post-MI. Infarction and fibrosis were determined by Masson trichrome staining and myoFBs identified by α-SMA immunofluorescence. Cardiac function was assessed by echocardiography and LV catheterization. WB, qPCR and Luciferase reporter assays were applied. Results The novel findings of this study are: (1) miR-221 protects CM and cFB through different mechanisms, namely combined anti-apoptotic and anti-autophagic effects vs. anti-autophagic alone, respectively. (2) For the first time we demonstrated that p53 is a direct target of miR-221; downregulation of total and phosphorylated p53 is associated with reduced apoptosis in CM while this effect is completely missing in cFB. Direct targeting of Ddit4 is responsible for anti-autophagy effects in both cell types. (3) miR-221 increases cFB in number but inhibits α-SMA activation and collagen synthesis. (4) Multiple predicted and previously reported targets of miR-221, e.g. Bmf, Puma, p27 and Tp53inp1, are down-regulated in cultured cells but are not affected in the heart in vivo. (5) Working through CM and cFB, miR-221 reduces infarct size, post-MI fibrosis and α-SMA+ cells in both infarct and remote myocardium, and improves LV function (as indicated by preserved ejection fraction, LV developed pressure, +/− dP/dt and end diastolic pressure). Conclusion miR-221 prevents CM and cFB death without extension of injury-stimulated cardiac fibrosis in the infarct zone or adverse fibrosis in the peri-infarct zone. The integrated effects of miR-221 ameliorate adverse post-ischemic LV remodeling and augment cardiac functional recovery. Therefore miR-221 is a unique therapeutic target in the treatment of cardiac infarction.

Background MicroRNAs regulate gene expression post-transcriptionally via complementary sequence pairing of mRNA 3'UTR and miRNA seed region. MiR-221 downregulates p27kip1 Cyclin-dependent kinase inhibitor 1B (p27), a cell cycle inhibitor, through direct targeting. The down-regulation of p27 caused by miR-221 upregulation induces cancer cell proliferation and has been reported to be closely associated with human cancer metastasis. This regulation is dependent on the existence of pumilio 1 (PUM1). Meanwhile miR-221 mimics protect cardiac myocytes against ischemic injury. It is a potential therapeutic target for cardioprotection. We investigated whether miR-221 targeted p27 in the heart. Purpose To test the hypothesis that the regulation of miR-221 on p27 is abolished in the heart due to lack of RNA binding protein (RBP) PMU1 phosphorylation but not due to p27 3'UTR shortening. Methods Primary cardiac fibroblasts (cFB) were isolated and cultured under normoxia and hypoxia. After transfections of miR-221 mimics and mimic control (MC), cell proliferation was assessed by cell number, CCk-8 and Ki67 staining. In vivo rats undergoing left coronary artery ligation (MI) and Sham were treated with intravenous miR-221 mimics. Cells or cardiac tissue were collected to measure p27 and PUM1 by RT-qPCR and Western blot (WB). Full length p27 (coding plus 3'UTR sequence) and 3'UTR p27 sequence were quantified using specific primers. The ratio of 3'UTR/Full length was compared to indicate changes between groups. The ratios of 3'UTR/Full length were compared to indicate changes between groups. Results MiR-221 mimics significantly downregulated the expression of p27 mRNA and protein in cFB in both normoxia and hypoxia. P27 downregulation led to cFB proliferation, which could be abrogated by p27 overexpression. miR-221 mimic treatment increased cardiac miR-221 by ∼2–5 fold in Sham and ∼15 fold in MI. Whilst p27 expression was not affected in either Sham or MI hearts. Simultaneously α-SMA+ cells, an indication of cFB number and activation, were reduced by miR-221 mimic in Sham and MI heart. The ratios of p27 3'UTR/full length did not vary significantly between cultured cFB and heart (Sham and MI), indicating the 3'UTR length did not vary between cFB and the whole heart. PUM1 mRNA expression was stable in cFB and the heart. However, phosphorylated PUM1 was highly expressed in cFB but completely diminished in Sham and MI hearts. Conclusion MiR-221 downregulated p27 in primary cFB and induced cell proliferation in vitro. miR-221 could not regulate cardiac p27 expression nor increase cFB proliferation in vivo. MiR-221 induced p27 regulation was correlated with the presence or absence of phosphorylated PUM1. For the first time, we demonstrated that loss of phosphorylated PUM1 turns off the regulation of miRNA-221 on gene p27 in the heart. The mechanism of PUM1 phosphorylation warrant future investigation.

Background Coagulation is involved in fibroproliferative responses following acute myocardial infarction (AMI). Left ventricular (LV) remodeling following AMI is closely associated with progression to heart failure. Purpose We aimed to evaluate the association of plasma tissue factor (TF) coagulation activity with LV remodeling prior to heart failure in post-AMI patients. Methods This study was conducted in 228 subjects from the Post-AMI Left Ventricular Remodeling Biomarker Analysis (PAMILA) study and 57 healthy subjects. The post-AMI patients were divided into two age- and sex-matched groups: patients with adverse LV remodeling defined as an increase in LV end systolic volume by ≥15% over 6 months and patients with reverse LV remodeling defined as an decrease in LV end systolic volume by ≥15% over 6 months. TF coagulation activity was determined using human coagulation factor Xa generation based TF chromogenic activity assay and converted into concentrations of active TF (pM). Sodium-citrate anticoagulated plasma was collected at baseline (within 3 days after revascularization), 30 days and 6 months post-AMI. Results are presented as mean±S.E.M. One-way or two-way repeated measures ANOVA or a multiple multi-level longitudinal data analysis with structural equation model was used to assess differences in coagulation activity. P Results Plasma from healthy subjects and post-AMI patients at baseline had similar concentrations of active TF (TFa): 29.0±1.4 versus 29.1±0.7 pM. Patients treated with warfarin (15 out of 228 patients) showed lower plasma levels of TFa (mean difference −15.2 pM, [95% CI: −18.7, −11.7], p Conclusion Plasma TF coagulation activity decreased post-AMI but did not differ in patients with adverse versus reverse LV remodeling. Acknowledgement/Funding National University Health System Singapore (NUHS O-CRG 2016 Oct-23) to JW Wang

Background Coronary plaque burden and composition drive recurrent ischaemic events in coronary artery disease. Purpose We first investigated the association between plasma proteins and coronary plaque characteristics in a cohort of asymptomatic individuals with low-intermediate Framingham Risk Score. Plaque-related proteins were further evaluated in a second cohort of patients with acute coronary syndrome (ACS) to determine their prognostic value for predicting future myocardial infarction (MI). Methods We profiled 1305 plasma proteins using an aptamer-based array (SOMAscan) in asymptomatic individuals who had undergone 384-slice coronary computed tomography angiography. Plaques were categorized by composition as calcified or non-calcified. First, we identified proteins that were different (based on multiple testing adjusted p-values: q-value Results A total of 65 and 120 plasma proteins were significantly associated with calcified and non-calcified plaques respectively in the asymptomatic cohort (N=79). Of these 185 proteins, 23 proteins were differentially expressed (DE) between ACS patients with and without recurrent MI events (median follow-up 1811 days). The top three up-and down-regulated proteins in the recurrent MI group were macrophage-capping protein, trefoil factor 3 and cystatin-SN (median FC 1.22, 1.17 and 1.17; q-value 4.34x10–6, 2.18x10–4, 3.17x10–3 respectively) and fibroblast growth factor 20, lymphotoxin a2/b1 and vascular endothelial growth factor receptor 2 (median FC 0.92, 0.94 and −0.090; q-value 1.31x10–3, 9.45x10–3 and 3.90x10–3) respectively. The quartiles of these protein concentrations were also associated with risk of recurrent MI, (log-rank test p-value range from 2.71x10–7 to 0.04). Of the DE proteins, the adjusted hazards ratio (HR) of cystatin-SN in the highest quartile (Q4) was 1.44 times that of the first quartile (Q1) (adjusted HR: 1.44, 95% CI: 0.93–2.2) and higher plasma concentration of cystatin-SN was associated with increasing risk of recurrent MI events (Trend test p=0.004). On the other hand, the highest quartile of fibroblast growth factor 20 was associated with 44% reduction in risks of recurrent MI adjusted HR: 0.56, 95% CI of HR: 0.35–0.87), with significant trend test (p=0.0096). Conclusions Large-scale plasma proteomics identified novel plaque-related proteins predictive of recurrent coronary events in patients with ACS. Further studies may help unravel the biological underpinnings of these circulating proteins and their potential as novel prognostic biomarkers. Acknowledgement/Funding This work was supported by grant NMRC/CSA-INV/0001/2016 from the National Medical Research Council, Singapore.

Background Prediction of left ventricular (LV) remodeling post-acute myocardial infarction (AMI) remains challenging. Several circulating biomarkers have been associated with post-AMI LV remodeling, however, there is no biomarker available to distinguish adverse versus reverse LV remodeling. Purpose In this study, we aimed to assess the association of extracellular vesicles (EVs) associated proteins with LV remodeling post-AMI. Methods Plasma EVs were isolated via precipitation with dextran sulphate as we previously reported. The protein levels of EV associated von Willebrand factor (VWF), SerpinC1 (antithrombin-III), plasminogen and SerpinF2 (alpha 2-antiplasmin) were determined in the citrate-anticoagulated plasma from 57 healthy subjects and 200 patients recruited in the Post-AMI Left Ventricular Remodeling Biomarker Analysis (PAMILA) study. Patients were categorized into two groups: adverse LV remodeling (n=100) characterized by an increase or reverse LV remodeling (n=100) characterized by a decrease, in LV end systolic volume by ≥15% over 6 months. Patients' plasma was collected at baseline (within 3 days after percutaneous coronary intervention), 1 month and 6 months post-AMI. Log transformation of EV protein levels was performed for assessment in a multiple multi-level longitudinal data analysis with structural equation model (with level of significance fixed at 0.05). Results Compared to healthy subjects, baseline protein levels of EV associated VWF and SerpinF2 were significantly higher in post-AMI patients, whereas no difference was observed in SerpinC1 and plasminogen. Among the patients, those on statins (196 out of 200 patients) showed lower protein levels of EV associated VWF (p Conclusions Lower levels of EV associated coagulation proteins (VWF and SerpinC1) and higher levels of EV associated fibrinolytic proteins (plasminogen and SerpinF2) were presented in patients with adverse LV remodeling compared to those with reverse LV remodeling post-AMI. Acknowledgement/Funding National University Health System Singapore (NUHS O-CRG 2016 Oct-23) to JW Wang

Objectives This study sought to derive age-, sex-, and ethnic-appropriate adult reference values for left atrial (LA) and left ventricular (LV) dimensions and volumes, LV mass, fractional shortening, and ejection fraction (EF) derived from geographically diverse population studies. Background The current recommended reference values for measurements from echocardiography may not be suitable to the diverse world population to which they are now applied. Methods Population-based datasets of echocardiographic measurements from 22,404 adults without clinical cardiovascular or renal disease, hypertension, or diabetes were combined in an individual person data meta-analysis. Quantile regression was used to derive reference values at the 95th percentile (upper reference value [URV]) and fifth percentile (lower reference value [LRV]) of each measurement against age (treated as linear), separately within sex and ethnic groups. Results The URVs for left ventricular end-diastolic volume (LVEDV), LV end-systolic volume, and LV stroke volume (SV) were highest in Europeans and lowest in South Asians. Important sex and ethnic differences remained after indexation by body surface area or height for these measurements, as well as for the LRV for SV. LVEDV and SV decreased with increasing age for all groups. Importantly, the LRV for EF differed by ethnicity; there was a clear apparent difference between Europeans and Asians. The URVs for LV end-diastolic diameter and LV end-systolic diameter were higher for Europeans than those for East Asian, South Asian, and African people, particularly among men. Similarly, the URVs for LA diameter and volume were highest for Europeans. Conclusions Sex- and/or ethnic-appropriate echocardiographic reference values are indicated for many measurements of LA and LV size, LV mass, and EF. Reference values for LV volumes and mass also differ across the age range.

We aimed to address the conflict over whether the underlying lesion that leads to acute myocardial infarction (AMI) is representative of low-grade or high-grade stenosis. Because the development of collateral vessels is an indication of ischemia, their presence was used as a surrogate marker for the existence of a high-grade lesion.Coronary angiography was used to assess 159 patients, divided into two groups, with (Rentrop 1-3) and without (Rentrop 0) collateral vessels, who had AMI with ST-segment elevation for which they underwent a percutaneous coronary intervention with the implantation of a coronary stent and had baseline thrombolysis in myocardial infarction 0/1 flow.Of the 159 patients recruited, the presence of collateral vessels was detected in 95 (collateral group; 60%), indicating that the causal lesion was representative of a high-grade stenosis. Among these 95 patients, the Rentrop scores were 1, 2, and 3 in 57 (60%), 33 (34.7%), and six (5.3%) patients, respectively. Logistic regression analysis showed that a baseline thrombolysis in myocardial infarction 0 flow (hazard ratio, 4.6; 95% confidence interval, 1.4-14.6; P=0.01) and a culprit right coronary artery (hazard ratio, 3.0; 95% confidence interval, 1.4-6.2; P=0.007) were independent predictors of the development of collateral vessels.The majority of AMI cases can be attributed to a severe stenosis, as demonstrated by the presence of collateral vessels in 60% of the patients in this study.

BACKGROUND: Risk factor burden and clinical characteristics of patients with coronary artery disease (CAD) differ among ethnic groups. We related biomarkers to CAD severity in Caucasians, Chinese, Indians and Malays. METHODS: In the Dutch-Singaporean UNICORN coronary angiography cohort (n = 2033) we compared levels of five cardiovascular biomarkers: N-terminal pro-brain natriuretic peptide (NTproBNP), high-sensitivity C-reactive protein (hsCRP), cystatin C (CysC), myeloperoxidase (MPO) and high-sensitivity troponin I (hsTnI). We assessed ethnicity-specific associations of biomarkers with CAD severity, quantified by the SYNTAX score. RESULTS: Adjusted for baseline differences, NTproBNP levels were significantly higher in Malays than in Chinese and Caucasians (72.1 vs. 34.4 and 41.1 pmol/l, p

There is an increasing body of evidence suggesting a role for the urocortin (Ucn) peptides in blood pressure regulation and in the pathophysiology of cardiovascular disease. Both Ucn1 and Ucn2 have recently been shown to inhibit cardiac sympathetic nerve activity (CSNA) in sheep. However, there are few studies reporting the effects of Ucn3 on the sympathetic nervous system. Hence, this study performed in normal conscious sheep examines the effects of Ucn3 on CSNA. Intravenous Ucn3 (administered at doses of 25 and 100 μg) caused transient falls in arterial pressure (P = 0.025), more prolonged rises in heart rate (P < 0.001), and falls in stroke volume (P < 0.001) and peripheral resistance (P = 0.018). CSNA, measured as burst area and burst incidence, fell in a dose-dependent manner after Ucn3 bolus (all P < 0.001). CSNA burst frequency tended to be reduced after high-dose Ucn3. Ucn3 had no significant effect on plasma catecholamine levels. In conclusion, this study reports for the first time that Ucn3 induces potent inhibition of sympathetic traffic directed toward the heart. This provides further support for a role for Ucn3 in pressure and volume homeostasis and suggests that further investigation of potential therapeutic applications for Ucn3 in cardiovascular disease is warranted.

The association between cardiac sympathetic nerve activity (CSNA) and ventricular fibrillation (VF) during acute myocardial infarction (MI) has not been assessed in conscious animal models. During the first 60 min post-MI, mean blood pressure (MBP), heart rate (HR), and CSNA were recorded continuously in 20 conscious sheep. Resistant sheep ( group A, n = 10) were compared with susceptible sheep ( group B, n = 10) who developed fatal VF ( n = 7) or sustained ventricular tachycardia (VT, n = 3). The mean time to VF/VT was 28.1 ± 3.3 min. In group B, MBP, HR, and CSNA were averaged at each consecutive minute from baseline at 14 min before the onset of VF/VT and compared with time-matched values in group A. When compared with those of group A, indexes of CSNA burst size increased before the onset of VF/VT: burst area/minute (F13,208 = 2.17, P = 0.01) and burst area/100 beats (F13,208 = 1.86, P = 0.04). By contrast, burst frequency indexes were not significantly different: burst frequency (F13,208 = 1.6, P = 0.09) and burst incidence (F13,208 = 1.48, P = 0.13). In group A, CSNA burst area/min and burst area/100 beats did not change across this time period (F13,117 = 0.97, P = 0.5, F13,117 = 0.96, P = 0.7) but increased with time in group B (F13,91 = 2.3, P = 0.01; and F13,91 = 2.25, P = 0.01). Between-group comparisons demonstrated no differences in time of onset of ventricular ectopic beats: 18.5 (range 12–24) in group A versus 15.0 min (range 7–22) in group B (Mann-Whitney U-test, P = 0.09). Pre-MI baroreflex slopes were similar: R-R slopes were 11.8 ± 2 and 15.6 ± 1.1 ms/mmHg ( t18 = −1.6, P = 0.14). CSNA slopes were −1.8 ± 0.3 and −2.3 ± 0.2%/mmHg ( t18 = −1.4, P = 0.2). An early increase in CSNA burst size indexes (before 60 min post-MI), mediated by an excitatory sympathetic reflex, is important in the genesis of VF/VT.

Whilst the tissue distribution and range of biological actions reported for apelin suggest a role for the peptide in pressure/volume homeostasis, conflicting reports make the precise role unclear. Furthermore, few integrated studies have been performed and there are no reports of bioactivity of apelin in a large animal model. Accordingly, we have examined the haemodynamic, hormonal and renal effects of apelin in ten normal conscious sheep. Apelin (1 mg i.v. bolus) induced a biphasic haemo-dynamic response characterised by an acute fall in arterial pressure and a rise in heart rate followed immediately by a rise in arterial pressure and a fall in heart rate. The secondary hypertensive phase was associated with a fall in cardiac output (P=0.015) and significant rises in calculated total peripheral resistance (CTPR) (PP=0.031). Electrocardiogram changes were also observed in four of ten sheep, most notably varying degrees of atrioventricular block. Apelin also induced significant rises in plasma arginine vasopressin (P=0.009), adrenocorticotrophin (P=0.012), aldosterone (P=0.001), cortisol (P=0.014), atrial (P=0.036) and brain (PP=0.003) and cyclic AMP (P=0.002) levels with no effect on renal indices. In conclusion, high dose administration of apelin to normal conscious sheep induces a significant biphasic response in arterial pressure and heart rate associated with rises in RAP and CTPR and a fall in cardiac output. Apelin also increases circulating levels of a number of vasoactive hormones. Taken together, these results suggest a potential role for apelin in pressure/volume homeostasis.

The sympathetic nervous system and adrenomedullin (AM) both participate in the regulation of cardiac and circulatory function but their interaction remains uncertain. We have examined the effects of AM on cardiac sympathetic nerve activity (CSNA) and hemodynamics and contrasted these effects with pressure-matched nitro-prusside (NP) administration in normal conscious sheep. Compared with vehicle control, arterial pressure fell similarly with AM (P=0.04) and NP (PPP=0.002) but the rise with AM was significantly greater than that induced by NP (PPPP=0.005) with the rise in burst frequency being greater with AM compared with NP (PP=0.03) and NP (P=0.002) with a trend for burst area being greater with AM than NP (P=0.07). CSNA burst incidence (bursts/100 beats) showed no significant differences between any treatment day. In conclusion, we have demonstrated that AM is associated with a greater increase in CSNA and heart rate for a given change in arterial pressure than seen with the classic balanced vasodilator NP.

Adrenomedullin (AM) may play a role in the pathophysiology of heart failure. Plasma levels of AM are raised in cardiovascular disease in proportion to severity of cardiac dysfunction, and plasma AM levels measured in acute myocardial infarction and heart failure are a useful prognostic indicator of outcome. AM administration in both experimental and human heart failure induces a beneficial spectrum of biological action including reduced arterial and atrial pressures, improved cardiac output, inhibition of plasma aldosterone and preservation or augmentation of urinary sodium excretion. Combining AM administration with either angiotensin-converting enzyme inhibition or neutral endopeptidase inhibition results in augmentation of the hemodynamic and renal effects of the individual treatments. Manipulating the AM system may prove beneficial as an adjunctive therapeutic strategy in cardiac disease.

SUMMARYEnvenoming by the Brazilian pit viper, Bothrops jararaca, induces extensive local and systemic haemorrhage in humans. The severe and occasionally lethal outcome of envenoming is prevented only by administration of antivenom which is conventionally prepared by hyperimmunization of large animals with an individual venom or a range of venoms. Since snake venoms typically consist of numerous molecules, only some of which are toxic, antivenoms are antigenically crude preparations whose therapeutic value would theoretically be enhanced by restricting antibody specificity to toxic venom molecules. We report here that high-titre IgG antibody from mice immunized by the GeneGun with DNA encoding the carboxy-terminal JD9 domain of Jararhagin, a haemorrhage-inducing metalloprotease in B. jararaca venom, extensively neutralized the main lethal component of B. jararaca venom. This is to our knowledge the first study to apply DNA-based methods to preparation of antivenom; it represents a novel approach with greater immunological specificity and fewer hazards than conventional systems of antivenom production.

Heterotopic ossification (HO) is a rare complication of head and spinal injuries, polio, orthopaedic surgery and burns. Three patients are reported, who developed severe HO following major, life-threatening burn injury. The aetiology, diagnosis and treatment of this condition are discussed. Particular attention is given to measures which may help reduce morbidity.

To determine the neurohormonal response to angiotensin-converting enzyme (ACE) inhibition after acute myocardial infarction, 36 patients presenting within 6 h of the onset of chest pain were studied in a single regional cardiology service. In this double-blind study, 13 patients were randomized to receive captopril, 12 patients received enalapril, and 11 patients received placebo, for 12 months. In patients receiving placebo, acute myocardial infarction was associated with activation of the renin-angiotensin-aldosterone and sympathetic nervous systems, and stimulation of plasma brain natriuretic peptide and atrial natriuretic peptide levels. ACE inhibition did not significantly alter circulating levels of norepinephrine, brain natriuretic peptide or atrial natriuretic peptide. Compared with placebo, enalapril induced a steep decline in plasma ACE activity, and plasma angiotensin II levels were reduced by both ACE inhibitors. Using grouped data, circulating levels of brain natriuretic peptide at the zero sampling time were significantly higher than atrial natriuretic peptide values. Brain natriuretic peptide levels at 72 h were significantly correlated with the radionuclide left ventricular ejection fraction measured 5 days and 3 months after infarction. Similar associations were observed for atrial natriuretic peptide and norepinephrine. We confirm activation of the renin-angiotensin-aldosterone and sympathetic nervous systems after acute myocardial infarction. The atrial natriuretic peptide and brain natriuretic peptide and sympathetic nervous system responses to acute myocardial infarction were not significantly modified by ACE inhibition. Brain natriuretic peptide and atrial natriuretic peptide levels were significantly correlated with the left ventricular ejection fraction measured 5 days and again 3 months after myocardial infarction, and may prove a useful prognostic index.

KCNE5 Gene Variant, QTc and Survival in ACS. Introduction: The KCNE family is a group of small transmembrane channel proteins involved in potassium ion (K + )c onductance. The X-linkedKCNE5 gene encodes a regulator of the K + current mediated by the potassium channel KCNQ1. Polymorphisms in KCNE5 have been associated with altered cardiac electrophysiological properties in human studies. We investigatedassociationsofthecommonrs697829polymorphismfromKCNE5withbaselinecharacteristics, baselineelectrocardiographic (ECG)measurements,andpatientsurvivalinacohortofpost-acutecoronary syndromes (ACS) patients (the Coronary Disease Cohort Study cohort). Methods and Results: DNA samples (n = 1,740) were genotyped for rs697829 using a TaqMan assay. Baseline ECG data revealed corrected QT (QTc) interval was associated with rs697829 in male, but not female, patients, being extended in the G genotype group (A 416 ± 1.71; G 431 ± 4.25 ms, P = 0.002). Covariate-adjusted survival was poorest in G genotype patients in Cox proportional hazard modeling of mortality data of males (Poverall = 0.020). Male patients with G genotype had a hazard ratio of 1.44 (1.11‐2.33) for death when compared to the A genotype male patients (P = 0.048) after adjustment for age, baseline log-transformed N-terminal pro-B-type natriuretic peptide (NTproBNP), ! -blocker and insulin treatment, QTc interval, history of myocardial infarction, and physical activity score. Conclusion: This study suggests an association between rs697829, a common single nucleotide polymorphism (SNP) from KCNE5, and ECG measurements and survival in postacute ACS patients. Prolonged subclinical QT interval may be a marker of adverse outcome in this group of patients. (J Cardiovasc

Although blood pressure effects have been reported for adrenomedullin 5 (AM-5), a newly identified member of the calcitonin gene-related peptide superfamily, little is known about other biological actions. We report the integrated hemodynamic, hormonal, and renal actions of AM-5 (10 and 100 ng·kg·min each for 90 minutes) in normal conscious sheep. AM-5 reduced the mean arterial pressure by 12 mm Hg at the end of the high dose (P < 0.001) in association with dose-dependent increments in the heart rate (40 beats/min--high dose, P < 0.001) and cardiac output (50%-high dose, P < 0.001) and dose-dependent falls in calculated total peripheral resistance (P < 0.001). Plasma renin activity (4-fold increment, P < 0.001), aldosterone (2-fold increment, P = 0.014), and cyclic adenosine monophosphate (50% increment, P < 0.001) all rose in response to high dose AM-5. Urine volume and sodium excretion were unchanged. In conclusion, it is observed that intravenous infusions of AM-5 administered to normal conscious sheep induced significant hemodynamic actions including reduced mean arterial pressure and calculated total peripheral resistance and increased heart rate and cardiac output. Concurrently, AM-5 activated plasma cyclic adenosine monophosphate, plasma renin activity, and aldosterone. These actions are similar to those previously reported for AM and AM-2. Thus, AM-5 may be an another important regulator of volume and pressure homeostasis and may play a role in the pathophysiology of heart disease.

The acute renal, endocrine, and hemodynamic effects of the orally active endopeptidase inhibitor SCH 34826 (400 mg every 6 hours for five doses) were investigated in a group of 6 male patients [with established mild to moderate essential hypertension and left ventricular (LV) hypertrophy] in a balanced random-order double-blind, placebo-controlled cross-over study. Plasma atrial natriuretic factor (ANF) concentrations increased (p < 0.05) to fourfold control values after the first dose of inhibitor, but later postdose increments of ANF were less pronounced. Plasma cyclic GMP also increased significantly (p < 0.05). These effects were associated with a transient modest but significant (p < 0.05) increase in sodium excretion (50 mmol sodium in excess of placebo values) that was complete in 24 h. Mean 24-h urinary excretions of cyclic GMP and immunoreactive ANF were also significantly increased by 55 and 86%, respectively. Other urine indexes (including other electrolytes, volume, creatinine, aldosterone, and cortisol) and renal hemodynamics [including glomerular filtration rate (GFR) and effective renal plasma flow (RPF)] were unchanged. Renin-angiotensin-aldosterone system (RAAS) activity was not significantly altered. Plasma epinephrine increased after the initial three doses of SCH 34826. Systolic blood pressure (SBP) and heart rate (HR) were not altered by SCH 34826. Diastolic BP (DBP) increased slightly (p = 0.044). Acute inhibition of endopeptidase 24.11 by SCH 34826 in essential hypertension caused significant increments in plasma ANF and cyclic GMP together with modest natriuresis. No antihypertensive effect was observed in the first 30 h of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Atrial natriuretic factor (ANF) cleaved between Cys105 and Phe106 is the primary metabolite of ANF and circulates in human plasma. Because the role of this metabolite in vivo and its possible interaction with intact ANF are unclear, we studied the biologic effects of a 2-h infusion of rat cleaved ANF101-105/106-126 (15 pmol/kg/min) or vehicle alone in six normal sheep. Infusions of cleaved ANF increased venous plasma levels of cleaved ANF from less than 5 to 260 pmol/L and induced a progressive and significant increase in plasma cyclic GMP (p = 0.025) without significantly affecting plasma ANF levels. These changes were associated with a small (nonsignificant) decrease in arterial pressure and a significant increase in heart rate (HR) and sympathetic nervous activity and were followed by activation of the renin-angiotensin-aldosterone (RAA) axis after infusions were terminated. Unlike ANF itself, cleaved ANF was not natriuretic and did not reduce plasma volume or right atrial pressure. Calculated metabolic clearance rate (MCR) (1.47 +/- 0.4 L/min) and disappearance rate of cleaved ANF from plasma (4.8 +/- 0.37 min) were similar to values reported previously for intact ANF in sheep. These studies show that cleaved ANF stimulates guanylate cyclase and alters hemodynamics and the RAA system in vivo.

The reaction between aluminium compounds and 1,4-dihydroxyanthraquinone (quinizarin QH 2 ) results in the formation of a highly fluorescent pink-red complex the properties of which are dependent upon the nature of the solvent, the mole ratio of the aluminium, the type of compound used and the pH. According to the method of continuous variation, complexes are formed with stoichiometries of 1:1 and 2:1 aluminium to quinizarin. However, using the mole ratio method, the progressive addition of aluminium results in a gradual increase in both the absorption and fluorescence quantum yield suggesting the formation of higher order complexes with polymeric characteristics. Flash photolysis studies on the aluminium complexes in nitrogen saturated 2-propanol gives rise to transient absorptions in the region 300-450 nm due to the semiquinone radical produced by the triplet-state of the complex abstracting a hydrogen atom from the solvent. The transient absorption is dependent upon the mole ratio of aluminium used to produce the complex and it is quenched with increasing aluminium concentration due to an intra-molecular triplet quenching process. Complexes of iron, cobalt and zinc were also prepared with quinizarin and found to have 1:1 stoichiometries with the latter exhibiting some polymeric properties. End-of-pulse transient absorption spectra are obtained in the region 300–650 nm and found to be dependent on the magnetic properties of the metal ions. Both the paramagnetic iron and cobalt exhibit a strong quenching effect compared with that obtained with quinizarin while the diamagnetic zinc has no such effect. The photoconductive properties of the 1:2 aluminium complex prepared with the acetylacetonate compound are examined in a single layer system in polyvinylcarbazole. Initial charge acceptance is found to be higher under positive charging and increases with increasing concentration of the complex and has maximum photoresponse at 10–20% w/w concentration. Both charge acceptance and photoresponse are more effective under positive than negative charging indicating that the complex is an effective electron-donor.

Co-localization of urocortin (Ucn) and its putative receptor (CRF-R2beta) in peripheral tissues, including the heart and vasculature, suggests an important role for the peptide as a regulator of cardiovascular function. Indeed, Ucn gene expression and/or immunoreactivity are increased in the ventricles of patients with failing hearts. Hemodynamic effects of Ucn include vasodilation and increases in cardiac contractility, coronary blood flow and conductance, cardiac output and heart rate. Due to the likely benefit of such actions in states of cardiac compromise, our laboratory has recently reported the first study examining the effects of Ucn in ovine experimental heart failure. We observed profound and sustained cardiovascular (reduced cardiac preload and afterload and increased cardiac output), hormonal (inhibition of vasopressin, endothelin and renin-angiotensin-aldosterone axis) and renal effects (natriuresis, diuresis and augmented creatinine clearance). Such effects incorporate many of the therapeutic goals of heart failure management. Recently, two further members of the CRF peptide family have been identified. In contrast to Ucn, Ucn II and III are reported to be highly selective for the CRF-R2beta, displaying negligible affinity for CRF-R1. As such, one could speculate that these new peptides might produce the salutary effects in heart failure as seen with Ucn, without concomitant activation of the stress-related hormone ACTH (mediated via CRF-R1). Clearly, further study is essential to confirm whether manipulation of this new family of peptides (especially Ucn II and Ucn III) offers benefit to the syndrome of heart failure with potential clinical applications in humans.

GeneGun DNA immunisation is a potent means of inducing antibody-dominant immune responses that we are exploiting to generate venom toxin-specific antibodies to improve the therapy of systemic envenoming by snakes. Here, we report that mice immunised with DNA encoding the carboxyl domain (JD9) of a haemorrhagic Zn metalloprotease (Jararhagin) in venom of the South American pit viper, Bothrops jararaca, and a plasmid expressing murine cytokine granulocyte/macrophage-colony stimulating factor (GM-CSF) raised significantly higher antigen-specific IgG1 titres than mice immunised with JD9 DNA alone. Serological responses to GeneGun JD9 DNA immunisation were shown to be dominated by IgG1, an IgG subclass associated with T lymphocyte helper 2 (Th2) immune responses. Further significant enhancement of JD9-specific IgG1 titres was achieved by increasing the number of immunisations. This report illustrates that DNA immunisation protocols to achieve high-titre, venom toxin-specific antibody production are well advanced and encourage the development of a DNA-based approach to antivenom production.

We describe the sixth reported case of Laurin-Sandrow syndrome. This spectrum of congenital abnormalities includes complex syndactyly, often associated with ulnar duplication, mirror feet and columella deformities. We discuss Laurin-Sandrow syndrome and report on its surgical management.

The renin-angiotensin system is central to the pathophysiology of a number of cardiovascular disorders. Most obviously this is so with renin secreting tumours, but the system is of central importance in other disorders such as scleroderma renal crisis and most cases of malignant hypertension. Activation of the renin-angiotensin system in unilateral renal artery stenosis is pivotal to the development of hypertension and the disturbances in electrolyte and volume balance -- most particularly in the hyponatraemic-hypertensive syndrome. Likewise, stimulation of the renin-angiotensin system is an important contributor, amongst many other systems, to the pathophysiology of cardiac failure. In diabetic nephropathy, the renin-angiotensin system is often suppressed as gauged by circulating levels of renin, yet it appears to make an important contribution to the progressive decline in renal function. Much less clear is the role of the renin-angiotensin system in essential hypertension insofar as it contributes to the level of blood pressure, to the development of left ventricular hypertrophy, and in the evolution of complications such as stroke and myocardial infarction. Blockade of the renin-angiotensin system with angiotensin-converting enzyme inhibitors has contributed to our understanding of the role of this system in cardiovascular disease. The advent of selective angiotensin II type-1 receptor blockers will further increase knowledge in this area.

One of the tests used routinely for the preclinical assessment of antivenom efficacy is the WHO-approved rodent intradermal skin test for assessing neutralization of venom-induced haemorrhagic activity. This is a useful test as in many viperid venoms haemorrhage is considered to be the principal lethal (pathogenic) venom effect in envenomed humans. The main problems with such an assay are, first, the necessity of using large numbers of experimental rodents (rats or mice) in order to obtain statistically significant results and, second, that the test must result in pain for the animals during the 24 hr assay period. The present study compares the rodent assay with an alternative assay using venom, in both the presence and absence of antidote, applied to a filter paper disc and placed on the highly vascularized yolk sac membrane of chickens' eggs at an early developmental stage. This avoids sensitivity to pain as reflex arcs have not yet developed, and haemorrhage or neutralization/inhibition of haemorrhage can be easily recorded. Preliminary results showed a high level of correlation between the results of the two tests when used to assess the efficacy of an antidote. It is hoped that the new assay will reduce the need for pain-sensitive experimental animals in the future.

Purpose: Although large scale clinical trials have demonstrated the efficacy and safety of pharmacological treatment for systolic heart failure (HF), HF treatment non-response was a common clinical observation. We sought to evaluate the role of HF biomarkers in prediction of HF treatment response. Methods: The participating sites from 3 countries have recruited a total of 646 patients with systolic HF, of which 299 patients have completed 6-months follow-up. HF treatment "Non-responders" was defined as death, re-hospitalization for HF, and/or reduction of left ventricular end-systolic volume of

Bothrops xanthogrammus/asper, B. atrox and Lachesis muta are probably responsible for most cases of severe envenoming in Ecuador. In recent years, the most widely used antivenom ('Myn' Ronti, imported from Mexico) has proved clinically ineffective. There is an urgent need to identify an effective alternative for clinical testing. Five antivenoms with activity against Bothrops venoms were compared using standard World Health Organization rodent and in vitro assays: (i) 'Myn', Ronti Mexico SA ('B. atrox', 'Crotalus terrificus'), (ii) Instituto Butantan (Bothrops polyvalent, Brazil), (iii) Instituto Nacional de Hygiene y Medicina Tropical (Bothrops polyvalent, Ecuador), (iv) Instituto Nacional de Salud (B. asper, C. durissus and Lachesis muta, Colombia), and (v) Laboratorios Probiol (Bothrops, Lachesis and Crotalus, Colombia). The venoms against which these antivenoms were tested were Ecuadorian B. atrox, B. asper and B. xanthogrammus. Brazilian antivenom proved to be the most effective, followed by the Ecudorian and Colombian antivenoms. Mexican antivenom was completely ineffective in neutralizing the lethal effects of Ecuadorian Bothrops venoms. Monospecific Brazilian L. muta antivenom (Instituto Butantan) proved effective against Ecuadorian L. muta venom, but the Colombian polyspecific antivenoms did not. Clinical trials of Brazilian and Ecuadorian antivenoms are planned in the Amazon region of Ecuador in the near future.

Connexin molecules oligomerize to form gap junctional channels and hemichannels that are present in cardiovascular system, in which, up to 4 types of connexins, connexin37 (C× 37), C× 40, C× 43, and C× 45, exist. Genomic analysis has shown that the C1019T single nucleotide polymorphism (SNP) of Cx37 gene is associated with coronary artery disease. Two C× 40 SNPs (C× 40 44 and +71 allele) within the regulatory regions have been shown to be associated with atrial fibrillation. Since coronary artery disease and atrial fibrillation are common causes of heart failure, polymorphism of human C× 37 and C× 40 may contribute to the development of heart failure. On the other hand, heart failure also alters the expression of connexins in both cardiomyocytes and vascular cells. For cardiomyocytes in heart failure, down-regulation and redistribution of connexins is a common phenomenon. Our recent data showed that endothelial C× 43 is downregulated in heart failure. In vitro experiments demonstrated that reduction of C× 43 in endothelial cells activates the cells to pathological status, as characterized by up-regulation of coagulatory molecules, impairment of proliferation, viability, and angiogenesis, and increased transendothelial permeability. In conclusion, connexins in cardiovascular system plays a multi-faceted role in heart failure. Down-regulation of endothelial C× 43 in heart failure may contribute to the manifestation of endothelial dysfunction, which commonly accompanies heart failure.