Bioengineering silicon quantum dot theranostics using a network analysis of metabolomic and proteomic data in cardiac ischemia

Metabolomic profiling is ideally suited for the analysis of cardiac metabolism in healthy and diseased states. Here, we show that systematic discovery of biomarkers of ischemic preconditioning using metabolomics can be translated to potential nanotheranostics. Thirty-three patients underwent percutaneous coronary intervention (PCI) after myocardial infarction. Blood was sampled from catheters in the coronary sinus, aorta and femoral vein before coronary occlusion and 20 minutes after one minute of coronary occlusion. Plasma was analysed using GC-MS metabolomics and iTRAQ LC-MS/MS proteomics. Proteins and metabolites were mapped into the Metacore network database (GeneGo, MI, USA) to establish functional relevance. Expression of 13 proteins was significantly different (p<0.05) as a result of PCI. Included amongst these was CD44, a cell surface marker of reperfusion injury. Thirty-eight metabolites were identified using a targeted approach. Using PCA, 42% of their variance was accounted for by 21 metabolites. Multiple metabolic pathways and potential biomarkers of cardiac ischemia, reperfusion and preconditioning were identified. CD44, a marker of reperfusion injury, and myristic acid, a potential preconditioning agent, were incorporated into a nanotheranostic that may be useful for cardiovascular applications. Integrating biomarker discovery techniques into rationally designed nanoconstructs may lead to improvements in disease-specific diagnosis and treatment.

Endocrine therapy for postmenopausal women with hormone receptor-positive her2-negative advanced breast cancer after progression or recurrence on nonsteroidal aromatase inhibitor therapy: a Canadian consensus statement

Approximately 22,700 Canadian women were expected to be diagnosed with breast cancer in 2012. Despite improvements in screening and adjuvant treatment options, a substantial number of postmenopausal women with hormone receptor positive (hr+) breast cancer will continue to develop metastatic disease during or after adjuvant endocrine therapy. Guidance on the selection of endocrine therapy for patients with hr+ disease that is negative for the human epidermal growth factor receptor 2 (her2-) and that has relapsed or progressed on earlier nonsteroidal aromatase inhibitor (nsai) therapy is of increasing clinical importance. Exemestane, fulvestrant, and tamoxifen are approved therapeutic options in this context. Four phase iii trials involving 2876 patients-efect, sofea, confirm, and bolero-2-have assessed the efficacy of various treatment options in this clinical setting. Data from those trials suggest that standard-dose fulvestrant (250 mg monthly) and exemestane are of comparable efficacy, that doubling the dose of fulvestrant from 250 mg to 500 mg monthly results in a 15% reduction in the risk of progression, and that adding everolimus to exemestane (compared with exemestane alone) results in a 57% reduction in the risk of progression, albeit with increased toxicity. Multiple treatment options are now available to women with hr+ her2- advanced breast cancer recurring or progressing on earlier nsai therapy, although current clinical trial data suggest more robust clinical efficacy with everolimus plus exemestane. Consideration should be given to the patient's age, functional status, and comorbidities during selection of an endocrine therapy, and use of a proactive everolimus safety management strategy is encouraged.

Puberty and Age-related Changes in Susceptibility to Schistosome Infection

Recent data from outbreaks of schistosomiasis in immunologically naive populations have refuelled the debate concerning the nature or existence of protective, acquired immunity to schistosomiasis in humans. Data from endemic communities provide some compelling evidence for an abrupt change in reinfection rates that coincides with puberty. We suggest that the hormonal changes of adrenarche may hold the key to understanding the relative resistance to infection found in adults.

The cost effectiveness of genetic testing for CYP2C19 variants to guide thienopyridine treatment in patients with acute coronary syndromes: a New Zealand evaluation

BACKGROUND

A recent clinical trial has demonstrated that patients with acute coronary syndromes (ACS) and the reduced function allele CYP2C19*2 (*2 allele), who are treated with thienopyridines, have an increased risk of adverse cardiac events with clopidogrel, but not with prasugrel. The frequency of the *2 allele varies by ethnicity and the Maoris, Asians and Pacific Islanders of New Zealand have a relatively high incidence.

OBJECTIVE

Our objective was to evaluate, from a New Zealand health system perspective, the cost effectiveness of treating all ACS patients with generic clopidogrel compared with prasugrel, and also compared with the genetically guided strategy that *2 allele carriers receive prasugrel and non-carriers receive clopidogrel.

METHODS

A decision-tree model consisting of five health states (myocardial infarction, stroke, bleeding, stent thrombosis and cardiovascular death) was developed. Clinical outcome data (two TRITON-TIMI 38 genetic sub-studies) comparing clopidogrel and prasugrel for both *2 allele carriers and non-carriers were combined with the prevalence of the heterozygosity for the *2 allele in New Zealand Europeans (15%), Maoris (24%), Asians (29%) and Pacific Islanders (45%) to determine the predicted adverse event rate for the New Zealand population. National hospital diagnosis-related group (DRG) discharge codes were used to determine alternative adverse event rates, along with the costs of hospitalizations during the 15 months after patients presented with an ACS. The primary outcome measure was the incremental cost per QALY (calculated using literature-reported weights). Monte Carlo simulations and alternative scenario analysis based on both clinical trial and national hospital incidence were used. Additional analysis considered the overall TRITON-TIMI 38 rates. Costs (in New Zealand dollars [$NZ], year 2009 values) and benefits were discounted at 3% per annum.

RESULTS

Actual hospital-based adverse event rates were higher than those reported in the TRITON-TIMI 38 randomized controlled trial and the genetic sub-studies, especially for myocardial infarction and cardiovascular death, and for Maoris and Pacific Islanders. For both sources of adverse event rates, treating the population with prasugrel was associated with worse outcomes (QALYs) than clopidogrel. However, prasugrel became cost effective ($NZ31 751/QALY) when the overall TRITON-TIMI 38 rates were used. A genetic test to guide the selected use of prasugrel was cost effective ($NZ8702/QALY versus $NZ24 617/QALY) for hospital and clinical trial incidence, respectively. Based on the hospital rates, the genetically guided strategy was especially cost effective for Maoris ($NZ7312/QALY) and Pacific Islanders ($NZ7041/QALY). These results were robust to the sensitivity analysis, except the genetically guided strategy under the 15-month clinical trial event rate scenario ($NZ168 748/QALY) did not remain cost effective under a $NZ50 000 threshold.

CONCLUSIONS

Use of a genetic test to guide thienopyridine treatment in patients with ACS is a potentially cost-effective treatment strategy, especially for Maoris and Pacific Islanders. This treatment strategy also has the potential to reduce ethnic health disparities that exist in New Zealand. However, the results comparing clopidogrel and prasugrel are sensitive to whether the genetic sub-studies or the overall TRITON-TIMI 38 rates are used. While the national hospital event rates may be more appropriate for the New Zealand population, many assumptions are required when they are used to adjust the genetic sub-studies rates.

"Valve in valve" percutaneous aortic valve implantation for severe mixed bioprosthetic aortic valve disease

Transcatheter aortic valve implantation (TAVI) is an effective treatment for patients with severe aortic stenosis at high risk for surgical valve replacement. We present a case of successful, off-label transfemoral valve-in-valve implantation of the self-expandable Medtronic-CoreValve prosthesis in an inoperable elderly patient with structural deterioration of an existing bioprosthesis in the aortic position. This case illustrates that TAVI for a deteriorated aortic bioprosthesis is feasible in a patient who was not suitable for reoperation.

Transcatheter aortic valve implantation in end-stage renal disease

Valvular heart disease is common in patients with end-stage renal disease and, if symptomatic, may lead to valve replacement surgery. However, some patients with renal failure are deemed unsuitable for cardiac surgery, and in those patients who do undergo surgery, there is a significantly greater morbidity and mortality. Transcatheter aortic valve implantation (TAVI) is recognized as an option for high-risk patients with symptomatic aortic stenosis (AS). Here we describe two patients on haemodialysis who underwent TAVI with satisfactory outcomes. The role of TAVI is evolving and has the potential to play an important role for dialysis patients with AS.

GENESiS: creating a composite index of the vulnerability to anxiety and depression in a community-based sample of siblings

There is considerable evidence for a unitary and dimensional view of the genetic vulnerability to symptoms of anxiety and depression. The GENESiS (Genetic Environmental–Nature of Emotional States in Siblings) Study aims to use a multivariate approach to detect genetic loci that contribute to individual differences in this vulnerability dimension. The study used the UK General Practice Research Framework to generate a community-based sample of siblings. Questionnaire measures of anxiety/depression included the short form of the neuroticism scale from the revised Eysenck Personality Questionnaire (EPQ-N), the General Health Questionnaire (GHQ-12), and the anxious arousal and high positive affect subscales from the Mood and Anxiety Symptoms Questionnaire (MASQ-AA and MASQ-HPA). Genetic model-fitting of 2658 unselected sibships provided evidence for a single common genetic (familial) factor that accounted for a substantial proportion of the genetic variances and covariances of these four measures. Using the parameter estimates of this model, we constructed a composite index of this common genetic factor. This index, which has a sib correlation of 0.22, will be used as a quantitative phenotype in the molecular genetic phase of GENESiS. Twin Research (2000) 3, 316–322.

Clinical characteristics and outcome of apical ballooning syndrome in Auckland, New Zealand

BACKGROUND

Apical ballooning syndrome (ABS) mimics myocardial infarction but is characterised by transient left ventricular (LV) dysfunction without significant coronary artery obstruction.

METHODS

We prospectively identified 100 consecutive patients presenting in the Auckland region between March 2004 and July 2010 and obtained clinical, laboratory, electrocardiography, echocardiography, coronary angiography and long-term follow-up data.

RESULTS

Chest pain or dyspnoea were the most common presenting symptom, 95% were women (mean age 65 ± 11 years). An associated stressor was identified in two-thirds of patients, troponin was elevated in all patients, and one-third had ECG ST-elevation. There was a similar range of initial LV ejection fraction (EF), myocardial damage, LV recovery and prognosis in those with and without ST-elevation, and with and without identifiable stressors. One-quarter had a complicated in-hospital course. Lower admission LVEF, but not peak troponin level or ECG ST-elevation, was associated with a complicated in-hospital course. The mean follow-up was 3.0 ± 1.7 years. One patient died in hospital. Four died late after discharge, all from non-cardiac causes. Seven had recurrent ABS.

CONCLUSION

In this large, prospective, New Zealand ABS cohort a quarter of patients had a complicated in-hospital course, but almost all recovered, recurrence was infrequent and long-term prognosis dependent on associated non-cardiac disease.

First-in-human experience with the Medtronic Bifurcation Stent System

AIMS

The BRANCH study was a prospective, multicentre, non-randomised, single arm trial to investigate the feasibility, safety, efficacy, and performance of the bare metal Medtronic Bifurcation Stent System for the treatment of de novo bifurcation lesions.

METHODS AND RESULTS

Sixty patients were enrolled in the study. After a learning curve of one case at seven centres, 53 patients from six centres were prospectively treated. The primary endpoint was target vessel failure (TVF) at 30 days. Secondary endpoints included acute device, lesion, and procedure success and TVF at 12 months. Medina complex bifurcation lesions (1,1,1; 1,1,0; 1,0,1; 0,1,1) were treated in 71.7%. The stent was successfully implanted in 86.8% of cases. Acute device, lesion, and procedure success rates were 83.0%, 92.5%, and 88.7%, respectively. TVF occurred in 2/52 patients (3.8%) at 30 days. No other major adverse cardiac adverse events (MACE) occurred through 30 days follow-up. At 12 months, TVF occurred in 6/47 (12.8%) patients, and MACE occurred in 5/47 (10.6%) patients.

CONCLUSIONS

Results from the BRANCH study demonstrate that the Medtronic Bifurcation Stent System is safe and can be successfully and effectively deployed in a variety of bifurcation lesions with good clinical outcomes.