Multimarker Analysis of Serially Measured GDF-15, NT-proBNP, ST2, GAL-3, cTnI, Creatinine, and Prognosis in Acute Heart Failure.

BACKGROUND: Studies on serially measured GDF-15 (growth differentiation factor 15) in acute heart failure (HF) are limited. Moreover, several pathophysiological pathways contribute to HF. Therefore, we aimed to explore the (additional) prognostic value of serially measured GDF-15 using a multi-marker approach to more accurately predict HF risk. METHODS: TRIUMPH (Translational Initiative on Unique and Novel Strategies for Management of Patients With Heart Failure) is a prospective cohort of 496 patients with acute HF who were enrolled in 14 hospitals in the Netherlands between 2009 and 2014. Blood sampling was scheduled at 7 moments during 1-year follow-up. GDF-15, NT-proBNP (N-terminal pro-B-type natriuretic peptide), ST2 (suppression of tumorigenicity 2), galectin-3, troponin I, and creatinine were measured in a central laboratory. We associated repeated measurements of these biomarkers with the composite primary end point of all-cause mortality and HF rehospitalization, using multivariable joint modeling. RESULTS: Median age was 74 years, and 37% were women. Median baseline GDF-15 was 4632 pg/mL. The primary end point was reached in 188 (40%) patients. The average estimated GDF-15 level increased weeks before the primary end point was reached. The hazard ratio per 1 SD difference in log-GDF-15 was 2.14 (95% CI, 1.78-2.57) unadjusted, 1.96 (1.49-2.53) after adjustment for clinical confounders and 1.44 (1.05-1.91) when jointly modeled with all biomarkers. The adjusted HRs for NT-proBNP were 2.38 (1.78-3.33) and 1.52 (1.15-2.08), respectively. The multimarker model combining GDF-15, NT-proBNP, and troponin I provided a favorable risk discrimination (area under the curve=0.785). CONCLUSIONS: Sequentially measured GDF-15 independently and dynamically predicts risk of adverse outcomes during 1-year follow-up after index admission for acute HF. NT-proBNP remains a robust predictor among potential candidates. Multiple biomarkers should be considered for stratification in clinical practice. REGISTRATION: URL: https://www.trialregister.nl/trial/1783; Unique Identifier: NTR1893. (The trial can be found temporarily at https://trialsearch.who.int/Trial2.aspx?TrialID=NTR1893.).

NT-proBNP is associated with mortality and adverse cardiac events in patients with atrial fibrillation presenting to the emergency department.

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia in the emergency department. The CHA2 DS2 -VASc score helps to predict thromboembolic risk; however, the rate of other adverse cardiac events is more difficult to predict. HYPOTHESIS: The biomarker N-terminal pro-brain natriuretic peptide (NT-proBNP) has prognostic value in patients presenting to the emergency department with AF. METHODS: During a 1.5-year period, a prospective study was performed in consecutive patients presenting to the emergency department with AF on the presenting electrocardiogram. At baseline, NT-proBNP was measured. The primary endpoints were all-cause death and major adverse cardiac events (MACE: all-cause mortality, myocardial infarction, or revascularization). RESULTS: A total of 355 patients were included (mean age, 71 years; 55% male). The median duration of follow-up was 2 years. After adjustment for baseline variables, the logNT-proBNP was independently correlated with death (hazard ratio [HR]: 1.54, 95% confidence interval [CI]: 1.18-1.99) and MACE (HR: 1.27, 95% CI: 1.03-1.58). After adjustment for baseline variables, a high NT-proBNP value (>500 pmol/L) was independently correlated with death (HR: 2.26, 95% CI: 1.19-4.28), and for MACE a trend was seen (HR: 1.67, 95% CI: 0.96-2.91) compared with a low value (<250 pmol/L). CONCLUSIONS: In patients presenting to the emergency department with AF, higher NT-proBNP values are independently associated with an increased mortality and MACE. Therefore, this biomarker may be a useful prognostic marker in the management and treatment of these patients.

Orgasm induced torsades de pointes in a patient with a novel mutation with long-QT syndrome type 2: a case report.

INTRODUCTION: Congenital long-QT (LQT) syndrome can lead to torsades de pointes (TdP), which can deteriorate into ventricular fibrillation resulting in sudden death. Thus far, more than 16 genes have been linked to the LQT syndrome. We report an orgasm-induced TdP in a patient with LQT syndrome type 2 with a novel mutation in the KCNH2 gene. CASE PRESENTATION: A 24-year-old Caucasian woman with a medical history of depression, no medication use and no family history of sudden death, presented with recurrent syncope during sexual activity. Immediately after achieving orgasm during sexual intercourse she lost consciousness. Baseline 12-lead electrocardiogram revealed a wide based T-wave with a prolonged QTc-interval of 507 ms. During hospital admission runs of TdP were recorded. The patient was treated with magnesium, an oral beta-blocker, and an implantable cardioverter-defibrillator. Genetic testing (Sanger sequencing) revealed a novel mutation (c.361del) in the KCNH2 gene (chromosome 7q36). DISCUSSION: To date, orgasm-induced TdP as a first symptom in a patient with LQT2 has not been published previously. In studies with continuous blood sampling in healthy volunteers, large peaks in plasma epinephrine levels during orgasm were observed with fast post-orgasmic decline. However, in a large cohort study (402 patients of which 129 with LQT2), no patients experienced cardiac events during sexual activity, suggesting that these are indeed very rare. Nevertheless, the high levels of sympathetic adrenal hormones during orgasm may explain the timing of the TdP in our patient. The patient has remained free of syncope at 6 months of follow-up.

Obstructive giant cardiac tumour in a patient with chest pain and acute respiratory insufficiency.

A 77-year-old woman presented with dyspnoea and respiratory-related thoracic pain, which was accompanied by dizziness and fatigue but no syncopal attacks. Auscultation of the heart disclosed an opening snap with mid-diastolic murmur. Laboratory assessment revealed no abnormalities but an elevated D-dimer level (1.49 mg/l). Electrocardiography was normal. The chest radiograph showed an enlarged heart without other abnormalities. Computed tomography (CT) scan for a suspected diagnosis of pulmonary embolism was performed. The CT scan did not reveal pulmonary embolism, but a large cardiac tumour in the left atrium.

The predictive value of cardiac biomarkers in prognosis and risk stratification of patients with atrial fibrillation.

PURPOSE OF REVIEW: Atrial fibrillation is a significant public health issue considering its high prevalence in the general population, and is associated with an increased risk of cardiovascular mortality and morbidity and thrombo-embolic complications.Asymptomatic paroxysms of atrial fibrillation occur frequently in the first stages of the disease but patients present to the doctor at a relatively late stage when the associated complications have already taken place. It is crucial to identify such patients as early as possible in order to start preventive therapy. Clinical diagnostic tests to identify patients prone to atrial fibrillation complications have not yet been developed as the exact mechanism and substrate of subclinical atrial fibrillation are not known. Further research is necessary to understand the pathophysiology of subclinical atrial fibrillation and to identify potential risk markers that determine the development and prognosis of the disease. RECENT FINDINGS: Biomarkers have recently been identified which have been shown to be related to the incidence of atrial fibrillation and its prognosis. They reflect inflammation, neurohumoral activation and subclinical heart damage. SUMMARY: New biomarkers may help to understand the mechanisms of subclinical atrial fibrillation and signal the likelihood of disease progression. Such biomarkers, though subject to further validation, may be of value in predicting the prognosis and guiding the treatment of patients with atrial fibrillation. They may enhance the ability of risk scores to guide anticoagulant treatment strategies.

Minor elevations in troponin I are associated with mortality and adverse cardiac events in patients with atrial fibrillation.

AIMS: In patients with atrial fibrillation, minor troponin I elevation is regularly detected; however, the prognostic significance of this finding is unknown. We therefore sought to examine the prognostic value of elevated troponin I in patients with atrial fibrillation. METHODS AND RESULTS: A prospective study was conducted analysing all consecutive patients admitted with atrial fibrillation in a 2-year period. Patients with an ST-elevation myocardial infarction (MI) were excluded. Minor troponin elevation was defined as a troponin I level between 0.15 and 0.65 ng/mL, which is still below the 99th percentile of the upper reference limit. A positive troponin I was defined as ≥ 0.65 ng/mL. Study outcomes were all-cause mortality (death), death and myocardial infarction (death/MI), or all major adverse cardiac events (MACE: death, MI, or revascularization). A total of 407 patients were eligible for inclusion. The median duration of follow-up was 688 days. A minor elevation occurred in 81 (20%) patients and 77 (19%) had a positive troponin I. In a multivariate model, minor troponin I elevation and a positive troponin I were independently associated with death [hazard ratio (HR): 2.36, 95% confidence interval (CI): 1.17-4.73 for minor elevation and HR: 3.77, 95% CI: 1.42-10.02 for positive troponin I]. Also, there was an independent correlation between the combined endpoints of death/MI and MACE and both a minor elevation and a positive troponin I. CONCLUSION: Minor elevations in troponin I on hospital admission are associated with mortality and cardiac events in patients with atrial fibrillation and might be useful for risk stratification.

Magnetic resonance imaging of haemorrhage within reperfused myocardial infarcts: possible interference with iron oxide-labelled cell tracking?

AIMS: Magnetic resonance imaging (MRI) has been proposed as a tool to track iron oxide-labelled cells within myocardial infarction (MI). However, infarct reperfusion aggravates microvascular obstruction (MO) and causes haemorrhage. We hypothesized that haemorrhagic MI causes magnetic susceptibility-induced signal voids that may interfere with iron oxide-labelled cell detection. METHODS AND RESULTS: Pigs (n = 23) underwent 2 h occlusion of the left circumflex artery. Cine, T2*-weighted, perfusion, and delayed enhancement MRI scans were performed at 1 and 5 weeks, followed by ex vivo high-resolution scanning. At 1 week, MO was observed in 17 out of 21 animals. Signal voids were observed on T2*-weighted scans in five out of eight animals, comprising 24 +/- 22% of the infarct area. A linear correlation was found between area of MO and signal voids (R2 = 0.87; P = 0.002). At 5 weeks, MO was observed in two out of 13 animals. Signal voids were identified in three out of seven animals. Ex vivo scanning showed signal voids on T2*-weighted scanning in all animals because of the presence of haemorrhage, as confirmed by histology. Signal voids interfered with the detection of iron oxide-labelled cells ex vivo (n = 21 injections). CONCLUSION: Haemorrhage in reperfused MI produces MRI signal voids, which may hamper tracking of iron oxide-labelled cells.

Functional assessment of myoblast transplantation for cardiac repair with magnetic resonance imaging.

BACKGROUND: Contraction of transplanted myoblasts and their effects on function and remodeling after myocardial infarction remain controversial. AIM: We used magnetic resonance imaging (MRI) to study wall thickening and left ventricular (LV) function and geometry after myoblast transplantation. METHODS AND RESULTS: Three weeks after cryo-infarction rabbits were randomized to receive an injection of approximately 2 x 10(8) myoblasts (n=8) or medium (n=9) into the scar. Cine MRI and contrast enhanced (ce) MRI images were acquired before injection (baseline) and 4 weeks later (endpoint). Regional wall thickening was measured at the site of transmural hyperenhancement. In the control group, regional wall thickening decreased to -15.3+/-8.6% at baseline, which further decreased to -18.3+/-5.7% at endpoint. Further, end-diastolic volume increased from 3.96+/-0.27 to 5.00+/-0.46 ml and end-systolic volume from 2.23+/-0.19 to 2.96+/-0.30 ml (both P<0.05 vs. baseline), which was accompanied by increased LV wall volumes (P<0.05 vs. baseline). In contrast, myoblast transplantation increased regional wall thickening from -11.9+/-15.9% at baseline to 26.9+/-17.0% (P<0.05 vs. control), which resulted in significantly improved two-dimensional ejection fractions at the infarct level and prevented the increase in end-diastolic and end-systolic volumes and wall volume. CONCLUSION: Intracardiac myoblast transplantation after myocardial infarction improves regional wall thickening and prevents progressive left ventricular remodeling.

A novel model of cryoinjury-induced myocardial infarction in the mouse: a comparison with coronary artery ligation.

Mouse myocardial infarction (MI) models are frequently used research tools. The most commonly applied model is coronary artery ligation. However, coronary ligation often gives rise to apical aneurysmatic infarcts of variable size. Other infarct models include cryoinfarction, which produces reproducible infarcts of the anterior wall. Thus far, this model has not been extensively described in mice. Therefore, we developed a murine cryoinfarction model and compared it with coronary ligation. Studies were performed under isoflurane anesthesia with a follow-up of 4 and 8 wk. Cryoinfarction was induced using a 2- or 3-mm cryoprobe. Two-dimensional guided M-mode echocardiography was used to assess fractional shortening and left ventricular (LV) dimensions at baseline and end point. At end point, hemodynamics were assessed using a 1.4-Fr Millar catheter. Pressure-diameter relations were constructed by combining echocardiography and hemodynamic data. Histological and morphometric analyses of infarct and remote areas were performed. At 4 wk, 3-mm cryoinfarction resulted in decreased LV fractional shortening as well as decreased global LV contractility and relaxation, which was comparable with coronary ligation. No adverse remodeling was observed at this time point, in contrast with the ligation model. However, progressive LV remodeling occured between 4 and 8 wk after cryoinfarction with a further decline in hemodynamic parameters and LV pump function. Histologically, cryoinfarction resulted in highly reproducible, transmural, cone-shaped infarcts with reperfusion at the macrovascular level. These results indicate that the cryoinfarction model represents the anterior myocardial infarct with modest adverse remodeling and may thus be representative for infarcts encountered in clinical practice.

Intracardiac transplantation of a mixed population of bone marrow cells improves both regional systolic contractility and diastolic relaxation.

BACKGROUND: Pre-clinical and clinical studies suggest that transplantation of bone marrow-derived stem cells can improve global cardiac function. However, no quantitative assessment of regional systolic contraction and correlation with phenotype has been made. Therefore, we used our model of cryoinfarcted rabbit myocardium for intracardiac transplantation of a mixed population of bone marrow-derived cells and assessed both regional function and myogenic conversion of the cells. METHODS: Nineteen New Zealand white rabbits underwent cryoinjury of the left ventricle. Autologous bone marrow (BM) cells were expanded in vitro. After 2 weeks, either 1 x 10(8) mixed BM-derived progenitor cells (BM group, n = 11) or vehicle (control group, n = 8) were injected into the cryoinjured region. Regional systolic function was measured using micromanometry and sonomicrometry before and 4 weeks after cell injection; cell phenotype was evaluated histologically. RESULTS: All animals in the BM group significantly improved both systolic shortening (0.11 +/- 0.7 vs -0.05 +/- 0.05 mm in the control group, p < 0.05) and regional stroke work when compared with control (9.6 +/- 2.4 vs -1.2 +/- 1.2 mm . mm Hg, p < 0.003). In addition, the BM group had improved global diastolic function, as measured by minimum dP/dt and end-diastolic pressure. On histologic assessment, BM cells differentiated toward a myogenic phenotype. CONCLUSIONS: Transplanting a mixed population of marrow-derived cells that can adopt a myogenic phenotype improves regional contractility and diastolic relaxation after myocardial infarction.

Video-assisted thoracoscopic transplantation of myoblasts into the heart.

PURPOSE: Currently, cells are transplanted into injured myocardium either through thoracotomy for open surgical delivery or through catheterization for endoventricular or intracoronary delivery; both methods have limitations. Open surgical delivery limits the potential patient population, whereas catheter-based delivery limits the ability to visualize the injection site and confirm delivery of the cells to the appropriate region. In this study, we examine the feasibility of cell transplantation into myocardium using a minimally invasive thoracoscopic approach. DESCRIPTION: Seven swine underwent thoracoscopic cell transplantation. Using a prototype injection device, approximately 10 million myoblasts were injected into the anterior, lateral, posterior, and apical regions of myocardium. Animals were recovered up to 7 days, and after euthanasia, hearts were explanted for histology. EVALUATION: All seven swine had successful delivery of myoblasts into the defined injection sites, as confirmed by analysis of an operative video, magnetic resonance imaging of iron-oxide-labeled cells, and histologic examination. CONCLUSIONS: Thoracoscopic cellular cardiomyoplasty is feasible and allows the surgeon the benefits of direct visualization of the cell injection while minimizing morbidity associated with open cell delivery.

The effects of acute afterload change on systolic ventricular function in conscious dogs with normal vs. failing hearts.

BACKGROUND: To date, no data exist on the linearity and, therefore, the usefulness of the preload recruitable stroke work (PRSW) and end-systolic pressure-volume (ESPVR) relationships during acute afterload changes in heart failure. AIMS: Our aim was, therefore, to characterize both relationships in a model of ventricular pacing induced heart failure at baseline and during acute changes in afterload. METHODS: Dynamic left ventricular volume and transmural pressure were measured in 10 conscious dogs using sonomicrometry and micromanometry under control conditions and during heart failure produced by 3 weeks of rapid right ventricular pacing. Afterload was varied from baseline with intravenous infusions of nitroprusside and phenylephrine. Left ventricular function was assessed using the PRSW and ESPVR relationships. RESULTS: Cardiac output demonstrated a linear inverse relationship with afterload in both normal and failing hearts (r2>0.5, P<0.001) with failure producing a parallel, downward shift of the afterload (x) vs. cardiac output (y) relationship (P<0.01). Yet, afterload variation did not affect PRSW or ESPVR relationships in either normal or failing hearts (r2<0.12, P>0.05). CONCLUSION: Thus, the PRSW and ESPVR relationships are insensitive to acute afterload changes in both failing and normal hearts, and the failing left ventricle is no more afterload-sensitive than the normal heart.

Improved efficacy of stem cell labeling for magnetic resonance imaging studies by the use of cationic liposomes.

Labeling stem cells with FDA-approved superparamagnetic iron oxide particles makes it possible to track cells in vivo with magnetic resonance imaging (MRI), but high intracellular levels of iron can cause free radical formation and cytotoxicity. We hypothesized that the use of cationic liposomes would increase labeling efficiency without toxic effects. Rabbit skeletal myoblasts were labeled with iron oxide by: 1) uptake of iron oxide incorporated into cationic transfection liposomes (group I) or 2) customary endocytosis (group II). In both groups, cell proliferation and differentiation were measured and toxicity was assayed using trypan blue and ratio fluorescence microscopy with BODIPY 581/591 C11. The effects of the intracellular iron oxide on magnetic resonance image intensities were assessed in vitro and in vivo. Both methods resulted in uptake of iron intracellularly, yielding contrast-inducing properties on MRI images. In group II, however, incubation with iron oxide at high concentrations required for endocytosis caused generation of free radicals, a decrease in proliferation, and cell death. Cytotoxic effects in the remaining cells were still visible 24 h after incubation. Conversely, in group I, sufficient intracellular uptake for detection in vivo by MRI could be achieved at 100-fold lower concentrations of iron oxide, which resulted in a high percentage of labeled cells, high retention of the label, and no cytotoxic effects even after stressing the cells with a hypoxia-reoxygenation insult. The use of cationic liposomes for iron oxide stem cell labeling increases labeling efficiency approximately 100-fold without toxic effects. This technique results in high-contrast-inducing properties on MRI images both in vitro and in vivo and could thus be a valuable tool for tracking stem cells noninvasively.

Comparison of intracardiac cell transplantation: autologous skeletal myoblasts versus bone marrow cells.

BACKGROUND: Multiple cell types are being proposed for cardiac repair, but side-by-side comparisons are lacking. We tested the hypothesis that intracardiac transplantation of autologous bone marrow- or skeletal muscle-derived progenitor cells improve regional heart function to a similar degree. METHODS AND RESULTS: Thirty-nine New Zealand White rabbits underwent cryoinjury of the left ventricle and simultaneous hind limb bone marrow aspiration or soleus muscle biopsy. Both muscle and bone marrow cells were expanded in vitro. After 2 weeks, 10(8) skeletal muscle (SM group) or bone marrow-derived progenitor cells (BM group) were injected into the cryoinjured region (SM: n=12; BM: n=8). Medium alone was injected into the remaining animals (Control: n=16). Regional systolic function was measured using micromanometry and sonomicrometry at baseline, before, and 4 weeks after cell injection. Cell treatment resulted in a similar degree of improvement in a derivative of stroke work in the SM and BM groups (P=0.0026 and P=0.0085 versus Control, respectively). No significant difference was seen between BM and SM groups (P=0.9). On histology, engrafted cells were found in all of the cell treated animals. Injected myoblasts formed myotubes or muscle cells throughout the scar that expressed slow and fast myosin heavy chain. A subset of bone marrow cells differentiated toward a myogenic phenotype, as indicated by expression of desmin and alpha-sarcomeric actin in the engrafted areas. CONCLUSIONS: Transplantation and myogenic differentiation of bone marrow-derived progenitor cells increased regional systolic heart function after myocardial injury to a similar degree as skeletal myoblasts.