Michael Fu

Current state of knowledge on aetiology, diagnosis, management, and therapy of myocarditis: a position statement of the European Society of Cardiology Working Group on Myocardial and Pericardial Diseases

In this position statement of the ESC Working Group on Myocardial and Pericardial Diseases an expert consensus group reviews the current knowledge on clinical presentation, diagnosis and treatment of myocarditis, and proposes new diagnostic criteria for clinically suspected myocarditis and its distinct biopsy-proven pathogenetic forms. The aims are to bridge the gap between clinical and tissue-based diagnosis, to improve management and provide a common reference point for future registries and multicentre randomised controlled trials of aetiology-driven treatment in inflammatory heart muscle disease.

Angiotensin Receptor Neprilysin Inhibition Compared With Enalapril on the Risk of Clinical Progression in Surviving Patients With Heart Failure

Background— Clinical trials in heart failure have focused on the improvement in symptoms or decreases in the risk of death and other cardiovascular events. Little is known about the effect of drugs on the risk of clinical deterioration in surviving patients. Methods and Results— We compared the angiotensin-neprilysin inhibitor LCZ696 (400 mg daily) with the angiotensin-converting enzyme inhibitor enalapril (20 mg daily) in 8399 patients with heart failure and reduced ejection fraction in a double-blind trial. The analyses focused on prespecified measures of nonfatal clinical deterioration. In comparison with the enalapril group, fewer LCZ696-treated patients required intensification of medical treatment for heart failure (520 versus 604; hazard ratio, 0.84; 95% confidence interval, 0.74–0.94; P=0.003) or an emergency department visit for worsening heart failure (hazard ratio, 0.66; 95% confidence interval, 0.52–0.85; P=0.001). The patients in the LCZ696 group had 23% fewer hospitalizations for worsening heart failure (851 versus 1079; P<0.001) and were less likely to require intensive care (768 versus 879; 18% rate reduction, P=0.005), to receive intravenous positive inotropic agents (31% risk reduction, P<0.001), and to have implantation of a heart failure device or cardiac transplantation (22% risk reduction, P=0.07). The reduction in heart failure hospitalization with LCZ696 was evident within the first 30 days after randomization. Worsening of symptom scores in surviving patients was consistently more common in the enalapril group. LCZ696 led to an early and sustained reduction in biomarkers of myocardial wall stress and injury (N-terminal pro–B-type natriuretic peptide and troponin) versus enalapril. Conclusions— Angiotensin-neprilysin inhibition prevents the clinical progression of surviving patients with heart failure more effectively than angiotensin-converting enzyme inhibition. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT01035255.

Troponin T Percentiles from a Random Population Sample, Emergency Room Patients and Patients with Myocardial Infarction

BACKGROUND High-sensitivity cardiac troponin T (cTnT) assays detect small clinically important myocardial infarctions (MI) but also yield higher rates of false-positive results owing to increased concentrations sometimes present in patients without MI. Better understanding is needed of factors influencing the 99th percentile of cTnT concentrations across populations and the frequency of changes in cTnT concentrations >20% often used in combination with increased cTnT concentrations for diagnosis of MI. METHODS cTnT percentiles were determined by use of the Elecsys® hscTnT immunoassay (Modular® Analytics E170) in a random population sample, in emergency room (ER) patients, and in patients with non-ST-elevation MI (NSTEMI). Changes in cTnT concentrations were determined in hospitalized patients without MI. RESULTS The 99th cTnT percentile in a random population sample (median age, 65 years) was 24 ng/L. In ER patients <65 years old without obvious conditions that increase cTnT, the 99th cTnT percentile was 12 ng/L with little age dependence, whereas in those >65 years old it was 82 ng/L and highly age dependent. In hospitalized patients without MI the 97.5th percentile for change in the cTnT concentration was 51%-67%. cTnT remained below the 99th percentile (12 ng/L) in 1% of patients with NSTEMI until 8.5 h after symptom onset and 6 h after ER arrival. CONCLUSIONS Age >65 years was the dominant factor associated with increased cTnT in ER patients. This age association was more prominent in ER patients than in a random population sample. Changes in serial cTnT concentrations >20% were common in hospitalized patients without MI.

Hemodynamic improvement and removal of autoantibodies against β1-adrenergic receptor by immunoadsorption therapy in dilated cardiomyopathy

The removal of beta(1)-adrenergic receptor (beta(1)AR) autoantibodies by immunoadsorption (IA) has been proposed as a potential mechanism for the improvement of the left ventricular function in dilated cardiomyopathy (DCM). In the present study, the possible association between removal of the autoantibodies against the human beta(1)AR with the hemodynamic improvement induced by IA was investigated.IA was performed in 22 DCM patients (n=22; NYHA III-IV, EF<30%, stable medication). The beta(1)AR autoantibodies from column eluents (CE) were detected by enzyme-linked immunosorbent assay (ELISA) and BIAcore methods. CE of 32% (7/22) of the patients was found to be antibody-positive with ELISA or BIAcore. In addition, a bioassay system was also used for the detection of this autoantibody. Seventy-three percent (16/22) of the patients were found to be antibody-positive by this method. However, independent of the beta(1)AR antibody detection method, both antibody-positive and antibody-negative groups showed similar acute and prolonged hemodynamic improvements during IA therapy. Furthermore, antibody-positive and -negative groups received a comparable improvement of left ventricular ejection fraction. These results suggest that different mechanisms are involved in the hemodynamic improvement induced by IA. The beneficial hemodynamic effects induced by IA are not directly associated with the removal of beta(1)AR autoantibodies.

Efficacy and safety of LCZ696 (sacubitril-valsartan) according to age: insights from PARADIGM-HF

Background The age at which heart failure develops varies widely between countries and drug tolerance and outcomes also vary by age. We have examined the efficacy and safety of LCZ696 according to age in the Prospective comparison of angiotensin receptor neprilysin inhibitor with angiotensin converting enzyme inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure trial (PARADIGM-HF). Methods In PARADIGM-HF, 8399 patients aged 18–96 years and in New York Heart Association functional class II–IV with an LVEF ≤40% were randomized to either enalapril or LCZ696. We examined the pre-specified efficacy and safety outcomes according to age category (years): <55 (n = 1624), 55–64 (n = 2655), 65–74 (n = 2557), and ≥75 (n = 1563). Findings The rate (per 100 patient-years) of the primary outcome of cardiovascular (CV) death or heart failure hospitalization (HFH) increased from 13.4 to 14.8 across the age categories. The LCZ696:enalapril hazard ratio (HR) was <1.0 in all categories (P for interaction between age category and treatment = 0.94) with an overall HR of 0.80 (0.73, 0.87), P < 0.001. The findings for HFH were similar for CV and all-cause mortality and the age category by treatment interactions were not significant. The pre-specified safety outcomes of hypotension, renal impairment and hyperkalaemia increased in both treatment groups with age, although the differences between treatment (more hypotension but less renal impairment and hyperkalaemia with LCZ696) were consistent across age categories. Interpretation LCZ696 was more beneficial than enalapril across the spectrum of age in PARADIGM-HF with a favourable benefit–risk profile in all age groups.

Efficacy and safety of LCZ696 (sacubitril-valsartan) according to age

Background The age at which heart failure develops varies widely between countries and drug tolerance and outcomes also vary by age. We have examined the efficacy and safety of LCZ696 according to age in the Prospective comparison of angiotensin receptor neprilysin inhibitor with angiotensin converting enzyme inhibitor to Determine Impact on Global Mortality and Morbidity in Heart Failure trial (PARADIGM-HF). Methods In PARADIGM-HF, 8399 patients aged 18–96 years and in New York Heart Association functional class II–IV with an LVEF ≤40% were randomized to either enalapril or LCZ696. We examined the pre-specified efficacy and safety outcomes according to age category (years): <55 (n = 1624), 55–64 (n = 2655), 65–74 (n = 2557), and ≥75 (n = 1563). Findings The rate (per 100 patient-years) of the primary outcome of cardiovascular (CV) death or heart failure hospitalization (HFH) increased from 13.4 to 14.8 across the age categories. The LCZ696:enalapril hazard ratio (HR) was <1.0 in all categories (P for interaction between age category and treatment = 0.94) with an overall HR of 0.80 (0.73, 0.87), P < 0.001. The findings for HFH were similar for CV and all-cause mortality and the age category by treatment interactions were not significant. The pre-specified safety outcomes of hypotension, renal impairment and hyperkalaemia increased in both treatment groups with age, although the differences between treatment (more hypotension but less renal impairment and hyperkalaemia with LCZ696) were consistent across age categories. Interpretation LCZ696 was more beneficial than enalapril across the spectrum of age in PARADIGM-HF with a favourable benefit–risk profile in all age groups.

Impairment of Cardiac Function and Bioenergetics in Adult Transgenic Mice Overexpressing the Bovine Growth Hormone Gene1

Cardiovascular abnormalities represent the major cause of death in patients with acromegaly. We evaluated cardiac structure, function, and energy status in adult transgenic mice overexpressing bovine GH (bGH) gene. Female transgenic mice expressing bGH gene (n = 11) 8 months old and aged matched controls (n = 11) were used. They were studied with two-dimensional guided M-mode and Doppler echocardiography. The animals (n = 6) for each group were examined with 31P magnetic resonance spectroscopy to determine the cardiac energy status. Transgenic mice had a significantly higher body weight (BW), 53.2+/-2.4 vs. 34.6+/-3.7 g (P < 0.0001) and hypertrophy of left ventricle (LV) compared with normal controls: LV mass/BW 5.6+/-1.6 vs. 2.7+/-0.2 mg/g, P < 0.01. Several indexes of systolic function were depressed in transgenic animals compared with controls mice such as shortening fraction 25+/-3.0% vs. 39.9+/-3.1%; ejection fraction, 57+/-9 vs. 77+/-5; mean velocity of circumferential shortening, 4.5+/-0.8 vs. 7.0+/-1.1 circ/sec, p < 0.01. Creatine phosphate-to-ATP ratio was significantly lower in bGH overexpressing mice (1.3+/-0.08 vs. 2.1+/-0.23 in controls, P < 0.05). Ultrastructural examination of the hearts from transgenic mice revealed substantial changes of mitochondria. This study provides new insight into possible mechanisms behind the deteriorating effects of long exposure to high level of GH on heart function.

A putative placebo analysis of the effects of LCZ696 on clinical outcomes in heart failure

Aims Although active-controlled trials with renin–angiotensin inhibitors are ethically mandated in heart failure with reduced ejection fraction, clinicians and regulators often want to know how the experimental therapy would perform compared with placebo. The angiotensin receptor-neprilysin inhibitor LCZ696 was compared with enalapril in PARADIGM-HF. We made indirect comparisons of the effects of LCZ696 with putative placebos. Methods and results We used the treatment-arm of the Studies Of Left Ventricular Dysfunction (SOLVD-T) as the reference trial for comparison of an ACE inhibitor to placebo and the Candesartan in Heart failure: Assessment of Reduction in Mortality and morbidity-Alternative trial (CHARM-Alternative) as the reference trial for comparison of an ARB to placebo. The hazard ratio of LCZ696 vs. a putative placebo was estimated through the product of the hazard ratio of LCZ696 vs. enalapril (active-control) and that of the historical active-control (enalapril or candesartan) vs. placebo. For the primary composite outcome of cardiovascular death or heart failure hospitalization in PARADIGM-HF, the relative risk reduction with LCZ696 vs. a putative placebo from SOLVD-T was 43% (95%CI 34–50%; P < 0.0001) with similarly large effects on cardiovascular death (34%, 21–44%; P < 0.0001) and heart failure hospitalization (49%, 39–58%; P < 0.0001). For all-cause mortality, the reduction compared with a putative placebo was 28% (95%CI 15–39%; P < 0.0001). Putative placebo analyses based on CHARM-Alternative gave relative risk reductions of 39% (95%CI 27–48%; P < 0.0001) for the composite outcome of cardiovascular death or heart failure hospitalization, 32% (95%CI 16–45%; P < 0.0001) for cardiovascular death, 46% (33–56%; P < 0.0001) for heart failure hospitalization, and 26% (95%CI 11–39%; P < 0.0001) for all-cause mortality. Conclusion These indirect comparisons of LCZ696 with a putative placebo show that the strategy of combined angiotensin receptor blockade and neprilysin inhibition led to striking reductions in cardiovascular and all-cause mortality, as well as heart failure hospitalization. These benefits were obtained even though LCZ696 was added to comprehensive background beta-blocker and mineralocorticoid receptor antagonist therapy.

Induction of cardiomyopathy in severe combined immunodeficiency mice by transfer of lymphocytes from patients with idiopathic dilated cardiomyopathy.

Growing evidence suggests that autoimmune mechanisms play an important role in the pathogenesis of idiopathic dilated cardiomyopathy (DCM). The aim of the study was to evaluate the effects of transfer of lymphocytes from patients with DCM into severe combined immunodeficiency (SCID) mice on the heart structure and function. Thirty CB-17 SCID (6-8 weeks old) mice were used and divided into 3 groups (n=10). Mice were injected intraperitoneally with up to 25 × 10 peripheral blood lymphocytes (PBL) from either patients with DCM which contain human autoantibodies against cardiac Pj-adrenergic receptors and M2-muscarinic receptors (DCM group) or PBL from healthy controls (control-H group). Ten mice did not receive any injections and were used as baseline controls (control-N group). Echocardiography and morphological studies were performed seventy five days after the transfer. Results showed that in DCM group, left ventricle dimensions (LVD) in diastole were increased (4.2 ± 0.1mm) as compared to both control-H group (3.8 ± 0.1mm) and control-N group (3.6 ± 0.1 mm) (p < 0.01). Further, there was a trend for increased LVD in systole. Fractional shortening was not different between groups. Histological evaluation revealed accumulation of human lymphocytes in the capillaries and scarce infiltration of the lymphocytes in the hearts from DCM group. Diffuse fibrosis was significant increased in DCM mice as compared to mice receiving PBL from normal subjects (2.2 ± 0.3 % vs. 0.8 ± 0.1 %, p < 0.01). In conclusion, transfer of the PBL from the patients with DCM was able to induce early stage of heart dilatation in SCID mice. These data provide for the first time the direct evidence supporting that the autoimmune mechanism is important in the pathogenesis of human DCM

Growth hormone improves bioenergetics and decreases catecholamines in postinfarct rat hearts.

The aims of this study were to examine, in vivo, the effects of GH treatment on myocardial energy metabolism, function, morphology, and neurohormonal status in rats during the early postinfarct remodeling phase. Myocardial infarction (MI) was induced in male Sprague Dawley rats. Three different groups were studied: MI rats treated with saline (n 5 7), MI rats treated with GH (MI 1 GH; n 5 11; 3 mg/kgzday), and sham-operated rats (sham; n 5 8). All rats were investigated with 31 P magnetic resonance spectroscopy and echocardiography at 3 days after MI and 3 weeks later. After 3 weeks treatment with GH, the phosphocreatine/ATP ratio increased significantly, compared with the control group (MI 5 1.69 6 0.09 vs. MI 1 GH 5 2.42 6 0.05, P , 0.001; sham 5 2.34 6 0.08). Treatment with GH significantly attenuated an increase in left ventricular end systolic volume and end diastolic volume. A decrease in ejection fraction was prevented in GH-treated rats (P , 0.05 vs. MI). Myocardial and plasma noradrenaline levels were significantly lower in MI rats treated with GH. These effects were accompanied by normalization of plasma brain natriuretic peptide levels (sham 5 124.1 6 8.4; MI 5 203.9 6 34.7; MI 1 GH 5 118.3 6 8.4 ng/ml; P , 0.05 vs. MI). In conclusion, GH improves myocardial energy reserve, preserves left ventricular function, and attenuates pathologic postinfarct remodeling in the absence of induction of left ventricular hypertrophy in postinfarct rats. The marked decrease in myocardial content of noradrenaline, after GH treatment, may protect myocardium from adverse effects of catecholamines during postinfarct remodeling. (Endocrinology 141: 4592‐ 4599, 2000)