Cardiomyocyte apoptosis and progression of heart failure to transplantation

BACKGROUND: Cardiomyocyte apoptosis has been found in congestive heart failure, but its clinical significance has been difficult to study. We compared the occurrence of cardiomyocyte apoptosis in explanted hearts with the progression of severe heart failure until the need for transplantation. DESIGN: Using the TUNEL assay, apoptotic cardiomyocytes were quantified in explanted failing hearts from patients with either idiopathic dilated cardiomyopathy (n = 21) or ischaemic heart disease (n = 14). The percentage was compared with the clinical severity and progression of endstage heart failure. Samples obtained at autopsy and during open heart surgery served as controls. RESULTS: The number of apoptotic cardiomyocytes was significantly increased in failing hearts regardless of aetiology (medians 0.075% in ischaemic heart disease and 0.119% in dilated cardiomyopathy) compared with control myocardium. In patients with dilated cardiomyopathy, apoptotic cardiomyocytes were more numerous in subjects with a rapidly deteriorating clinical course (0.192%, n = 10) than in patients with intermediate (0.093%, n = 6, P = 0.03) or slow (0.026%, n = 5, P = 0.003) progression. No such association was observed in patients with ischaemic heart disease, in whom we found significantly increased cardiomyocyte apoptosis adjacent to scars of previous infarctions (0.576%) in contrast to the diffuse distribution seen in dilated cardiomyopathy. Expression of Bcl-2, an antiapoptotic protein, was increased in all failing hearts by immunohistochemistry. CONCLUSION: Cardiomyocyte apoptosis is a consistent feature of end-stage heart failure in man and appears to be quantitatively related to the clinical severity of deterioration in dilated cardiomyopathy. Increased expression of Bcl-2 in cardiomyocytes indicates activation of an antiapoptotic response. These observations suggest that cardiomyocyte apoptosis is a clinically relevant and potentially modifiable pathophysiological phenomenon in severe heart failure.     

Changes in gene expression in the intact human heart. Downregulation of alpha-myosin heavy chain in hypertrophied, failing ventricular myocardium.

Using quantitative RT-PCR in RNA from right ventricular (RV) endomyocardial biopsies from intact nonfailing hearts, and subjects with moderate RV failure from primary pulmonary hypertension (PPH) or idiopathic dilated cardiomyopathy (IDC), we measured expression of genes involved in regulation of contractility or hypertrophy. Gene expression was also assessed in LV (left ventricular) and RV free wall and RV endomyocardium of hearts from end-stage IDC subjects undergoing heart transplantation or from nonfailing donors. In intact failing hearts, downregulation of beta1-receptor mRNA and protein, upregulation of atrial natriuretic peptide mRNA expression, and increased myocyte diameter indicated similar degrees of failure and hypertrophy in the IDC and PPH phenotypes. The only molecular phenotypic difference between PPH and IDC RVs was upregulation of beta2-receptor gene expression in PPH but not IDC. The major new findings were that (a) both nonfailing intact and explanted human ventricular myocardium expressed substantial amounts of alpha-myosin heavy chain mRNA (alpha-MHC, 23-34% of total), and (b) in heart failure alpha-MHC was downregulated (by 67-84%) and beta-MHC gene expression was upregulated. We conclude that at the mRNA level nonfailing human heart expresses substantial alpha-MHC. In myocardial failure this alteration in gene expression of MHC isoforms, if translated into protein expression, would decrease myosin ATPase enzyme velocity and slow speed of contraction.     

Connective tissue growth factor and bone morphogenetic protein 2 are induced following myocardial ischemia in mice and humans

We aimed to study the cardiac expression of bone morphogenetic protein 2, its receptor 1?b, and connective tissue growth factor, factors implicated in cardiac embryogenesis, following ischemia/hypoxia, heart failure, and in remodeling hearts from humans and mice. Biopsies from the left ventricle of patients with end-stage heart failure due to dilated cardiomyopathy or coronary artery disease were compared with donor hearts and biopsies from patients with normal heart function undergoing coronary artery bypass grafting. Mouse model of post-infarction remodeling was made by permanent ligation of the left coronary artery. Hearts were analyzed by real-time polymerase chain reaction and Western blotting after 24?hours and after 2 and 4 weeks. Patients with dilated cardiomyopathy and mice post-infarction had increased cardiac expression of connective tissue growth factor. Bone morphogenetic protein 2 was increased in human hearts failing due to coronary artery disease and in mice post-infarction. Gene expression of bone morphogenetic protein receptor 1 beta was reduced in hearts of patients with failure, but increased two weeks following permanent ligation of the left coronary artery in mice. In conclusion, connective tissue growth factor is upregulated in hearts of humans with dilated cardiomyopathy, bone morphogenetic protein 2 is upregulated in remodeling due to myocardial infarction while its receptor 1?b in human failing hearts is downregulated. A potential explanation might be an attempt to engage regenerative processes, which should be addressed by further, mechanistic studies.     

Energetics and function of the failing human heart with dilated or hypertrophic cardiomyopathy

BACKGROUND: Impaired energy metabolism in the failing human heart could be an important mechanism of functional deterioration. The purpose of this study was to assess the changes of myocardial energy metabolism in the human heart at end-stage heart failure. MATERIALS AND METHODS: The left ventricular myocardium of patients undergoing heart transplantation due to dilated (DCM, n = 14) or hypertrophic cardiomyopathy (HCM, n = 5) and non-diseased donor heart samples (n = 4) were analysed for citrate synthase (CS), enzymes of the glycolytic pathway as well as concentrations of phosphocreatine (PCr), creatine (Cr), adenine and guanine nucleotides. RESULTS: Total creatine levels (phosphocreatine + creatine) were significantly decreased (P < 0.05) in both groups of diseased hearts (3.87 +/- 0.57 in DCM, 5.09 +/- 1.23 in HCM compared with control 10. 7 +/- 3.5 micromol g-1 wet weight). There was a trend for higher guanine nucleotide content in failing hearts, but no significant differences were observed in total adenine nucleotides and total NAD content. CS was markedly reduced (P < 0.05) in both groups of diseased hearts: in the DCM to 13.8 +/- 1.3 micromol min-1 g-1 wet weight, and in HCM to 11.9 +/- 2.4 compared with the control 29.2 +/- 2.2. Glycolytic enzymes were decreased compared with the control, and this decrease was greater in DCM than in HCM. Echocardiographic indices of contractility were considerably better in hypertrophic cardiomyopathy. CONCLUSION: Despite the different mechanisms of cardiac failure and the differences in contractility of the heart we have observed, metabolic changes are very similar in hypertrophic and dilated cardiomyopathy. Depletion of the creatine pool suggests an alteration in the intracellular energy reserves and transfer, whereas the decrease in citrate synthase activity suggests reduced oxidative capacity in both dilated and hypertrophic cardiomyopathy.     

Altered sarcoplasmic reticulum Ca2(+)-ATPase gene expression in the human ventricle during end-stage heart failure.

A decrease in the myocardial level of the mRNA encoding the Ca2(+)-ATPase of the sarcoplasmic reticulum (SR) has been recently reported during experimental cardiac hypertrophy and failure. To determine if such a deficit occurs in human end-stage heart failure, we compared the SR Ca2(+)-ATPase mRNA levels in left (LV) and right ventricular (RV) specimens from 13 patients undergoing cardiac transplantation (6 idiopathic dilated cardiomyopathies; 4 coronary artery diseases with myocardial infarctions; 3 diverse etiologies) with control heart samples using a rat cardiac SR Ca2(+)-ATPase cDNA probe. We observed a marked decrease in the mRNA for the Ca2(+)-ATPase relative to both the 18S ribosomal RNA and the myosin heavy chain mRNA in LV specimens of patients with heart failure compared to controls (-48%, P less than 0.01 and -47%, P less than 0.05, respectively). The LV ratio of Ca2(+)-ATPase mRNA to 18S RNA positively correlated with cardiac index (P less than 0.02). The RV ratio correlated negatively with systolic, diastolic and mean pulmonary arterial pressures (P less than 0.02, P less than 0.02, and P less than 0.01, respectively). We suggest that a decrease of the SR Ca2(+)-ATPase mRNA in the myocardium plays an important role in alterations of Ca2+ movements and myocardial relaxation reported during human end-stage heart failure.     

Transgenic expression of replication-restricted enteroviral genomes in heart muscle induces defective excitation-contraction coupling and dilated cardiomyopathy.

Numerous studies have implicated Coxsackievirus in acute and chronic heart failure. Although enteroviral nucleic acids have been detected in selected patients with dilated cardiomyopathy, the significance of such persistent nucleic acids is unknown. To investigate the mechanisms by which restricted viral replication with low level expression of Coxsackieviral proteins may be able to induce cardiomyopathy, we generated transgenic mice which express a replication-restricted full-length Coxsackievirus B3 (CVB3) cDNA mutant (CVB3DeltaVP0) in the heart driven by the cardiac myocyte-specific myosin light chain-2v (MLC-2v) promoter. CVB3DeltaVP0 was generated by mutating infectious CVB3 cDNA at the VP4/VP2 autocatalytic cleavage site from Asn-Ser to Lys-Ala. Cardiac-specific expression of this cDNA leads to synthesis of positive- and negative-strand viral RNA in the heart without formation of infectious viral progeny. Histopathologic analysis of transgenic hearts revealed typical morphologic features of myocardial interstitial fibrosis and in some cases degeneration of myocytes, thus resembling dilated cardiomyopathy in humans. There was also an increase in ventricular atrial natriuretic factor mRNA levels, demonstrating activation of the embryonic program of gene expression typical of ventricular hypertrophy and failure. Echocardiographic analysis demonstrated the presence of left ventricular dilation and decreased systolic function in the transgenic mice compared with wild-type littermates, evidenced by increased ventricular end-diastolic and end-systolic dimensions and decreased fractional shortening. Analysis of isolated myocytes from transgenic mice demonstrate that there is defective excitation-contraction coupling and a decrease in the magnitude of isolated cell shortening. These data demonstrate that restricted replication of enteroviral genomes in the heart can induce dilated cardiomyopathy with excitation-contraction coupling abnormalities similar to pressure overload models of dilated cardiomyopathy.     

Renal insufficiency and treatment of persistent cardiac insufficiency with converting enzyme inhibitor

The purpose of this retrospective study was to consider impaired renal function in patients with severe congestive heart failure after converting enzyme inhibition and to emphasize the characteristics of this population. The study concerned 26 patients (pts), 72.5 +/- 8.1 years old, with a severe congestive heart failure (NYHA Class IV). Before treatment serum creatinine was slightly increased and the introduction of angiotensin converting enzyme inhibitor (ACEI) - Captopril 58.9 +/- 17.3 mg/j or enalapril 9.2 +/- 4.4 mg - impaired renal function from 132.0 +/- 50.7 mumol/l to 183.5 +/- 139.3 mumol/l (n = 26; p less than 0.05). Patients were separated in 3 groups: in group I; 15 pts, serum creatinine remained unchanged under ACEI in despite of the significant decrease of blood pressure (BP); from 140.7 +/- 24.0/82.5 +/- 13.4 to 120.3 +/- 12.8/71.8 +/- 8.7 mmHg (p less than 0.01). The cause of heart failure was an ischemic heart disease (IHD) in 15 patients (chi 2 test, p less than 0.05), a dilated cardiomyopathy in 4 pts and an aortic or mitral valvular regurgitation in 2 pts. In contrast renal function was significantly impaired in group II; serum creatinine increased from 120.8 +/- 25.2 to 189.0 +/- 80.7 mumol/l under ACEI. BP remained unchanged 136.9 +/- 29.0/78.1 +/- 4.9 and 118.7 +/- 13.6/75.6 +/- 7.6 mmHg respectively before and after treatment. There was 4 pts with dilated cardiomyopathy, 4 pts with mitral or aortic valvular regurgitation and only one with IHD. The introduction of an ACEI in two pts--group III--with severe tricuspid regurgitation induced an acute and reversal renal failure (serum creatinine at 600 mumol/l).     

Soluble tumor necrosis factor receptor levels identify a subgroup of heart failure patients with increased cardiomyocyte apoptosis

BACKGROUND: We studied whether the presence of cardiomyocyte apoptosis (CA) in explanted failing hearts is related to previous exposure to the proinflammatory cytokine tumor necrosis factor alpha (TNF-alpha). METHODS: Serum levels of TNF-alpha and its soluble type two receptors (sTNFRII) were measured with ELISAs in 15 cardiac transplant recipients. CA was quantified with TUNEL assay in the explanted failing hearts and autopsy samples from six normal hearts. RESULTS: The number of CA was significantly higher in explanted failing hearts than in normal hearts (0.041% vs. 0.007%, p<0.01). In heart failure patients, serum TNF-alpha was highly variable and did not correlate with CA. In contrast, serum sTNFRII showed a significant correlation (Pearson's r=0.74, p=0.002) with the amount of CA in explanted hearts. sTNFRII level >4500 pg/ml identified seven patients with 2.7 times higher percentage of CA than the other heart failure patients. CONCLUSION: Increased levels of sTNFRII identify a heart failure patient subgroup with high CA activity.     

A new framework for echocardiographic assessment of left ventricular mechanics: sensitivity to heart failure.

A recent report describes an approach to ventricular mechanics that employs mean end-systolic fiber stress and an exact mathematical strain index based on wall thickness referenced to myocardial mass. We used echocardiography and mean arterial pressures to determine the strain index and wall stress in (1) normal hearts from patients and swine, (2) swine with pacing-induced congestive heart failure, and (3) patients with dilated cardiomyopathy. Pigs were also studied under afterload variation with phenylephrine. Paired values of stress and strain index from control hearts (both swine and human) were tightly clustered. Values from animals and patients with congestive heart failure deviated from this cluster. Excellent separation (sensitivity 83%, specificity 94%) was displayed between control and paced pigs, despite confounding effects of varying afterload. We conclude that these variables display little change over a large range of normal cardiac mass, but deviate from this range during heart failure.     

Myocardial imaging with 123I-BMIPP in patients with congestive heart failure

First, we studied the diagnostic utility of myocardial imaging with 123I-BMIPP (BMIPP), a 3-methyl-branched fatty acid analog, in patients with various types of cardiomyopathy and left ventricular dysfunction (ejection fraction below 40%) by comparing with myocardial flow tracer imaging. The incidence of a dissociation between myocardial BMIPP and 201Tl distributions (BMIPP< 201Tl) as a marker of metabolic abnormality in viable tissue varied considerably among various heart diseases. Patients with ischemic cardiomyopathy and the dilated form of hypertrophic cardiomyopathy had a higher incidence while those with idiopathic dilated, alcoholic and hypertensive cardiomyopathy had a lower incidence. These results suggest that the marked difference between ischemic and idiopathic dilated cardiomyopathies may contribute to the differential diagnosis between these two diseases which are main basic abnormalities in congestive heart failure. Second, we investigated the relationship between myocardial BMIPP uptake and ventricular stress in patients with right ventricular pressure overload due to pulmonary hypertension. Myocardial BMIPP uptake in the right ventricle estimated by referring to uptake in the left ventricle showed a significant correlation with mean pulmonary artery pressure (mPAP) and no significant difference with myocardial 99mTc-sestamibi uptake in the 15–81mmHg mPAP range. These results suggest that myocardial utilization of free fatty acid may be preserved in the presence of higher ventricular wall stress.     

Oxidized low-density lipoprotein is localized in the ventricles of hearts from patients with coronary heart disease

The present study was designed to investigate whether oxidized low-density lipoprotein is accumulated in the left and right ventricular walls of patients with coronary heart disease (n=10) compared with patients with dilated cardiomyopathy (n=9) or healthy heart donors (controls, n=5). Sections from both ventricles of explanted hearts and coronary arteries of the same patients were analyzed by semiquantitative immunohistochemistry for the presence of oxidized low-density lipoprotein. Oxidized low-density lipoprotein was enriched in the left and right ventricular walls from coronary heart disease patients compared with patients with dilated cardiomyopathy (P=0.0012 for left ventricle and P=0.103 for right ventricle) or controls (P=0.0012 for the left ventricle and P<0.05 for the right ventricle). The accumulation of oxidized low-density lipoprotein was higher in the left than in the right ventricles in all three groups. Positive immunoreactivity for oxidized low-density lipoprotein was mainly identified in the endocardium and the subendocardial areas of the ventricles and co-localized with macrophages. Accumulation of oxidized low-density lipoprotein in the ventricles significantly correlated with the enrichment in the respective coronary arteries, whereas only poor correlations were observed between various hemodynamic parameters and ventricular oxidized low-density lipoprotein accumulation. Ventricular accumulation of oxidized low-density lipoprotein seems to be a generalized pathophysiological process which does not exclusively involve the coronary arteries. Higher oxidative stress in combination with impaired oxygen supply in the endocardium could have favored low-density lipoprotein deposition and oxidation.     

Cardiomyopathies with particular reference to the diagnostic relevance of endomyocardial biopsies

A distinction is made between heart muscle diseases with a known cause, or occurring as part of a systemic disease, and those of unknown cause. The first category is termed "specific heart muscle disease". The term "cardiomyopathy" is then limited to the latter category. Cardiomyopathies are categorized as dilated cardiomyopathy, hypertrophic cardiomyopathy and restrictive cardiomyopathy. The pathology of dilated cardiomyopathy depends on the clinical stage of the disease. Basically, the histology shows hypertrophic myocytes, often with degenerative signs, and interstitial fibrosis. Lymphocytes may be observed, particularly in cases studied shortly after the onset of symptoms. Endocardial thickening may occur in time. The role of endomyocardial biopsies in the clinical setting is limited and relates mainly to excluding other diseases, such as myocarditis. The pathology of hypertrophic cardiomyopathy is characterized by myocardial wall thickening, either asymmetric or symmetric, and disorganization of the normal myocardial texture. The latter phenomenon should be distinguished from disarray, since it may occur as a natural phenomenon. The differentiation between these two may be extremely difficult on the basis of only small tissue samples, as with endomyocardial biopsies. This, therefore, poses serious limitations in the use of endomyocardial biopsies. The pathology of restrictive cardiomyopathy also depends on the stage of the disease.(ABSTRACT TRUNCATED AT 250 WORDS)     

Analysis of shape and motion of the mitral annulus in subjects with and without cardiomyopathy by echocardiographic 3-dimensional reconstruction.

The shape and dynamics of the mitral annulus of 10 patients without heart disease (controls), 3 patients with dilated cardiomyopathy, and 5 patients with hypertrophic obstructive cardiomyopathy and normal systolic function were analyzed by transesophageal echocardiography and 3-dimensional reconstruction. Mitral annular orifice area, apico-basal motion of the annulus, and nonplanarity were calculated over time. Annular area was largest in end diastole and smallest in end systole. Mean areas were 11.8 +/- 2.5 cm(2) (controls), 15.2 +/- 4.2 cm(2) (dilated cardiomyopathy), and 10.2 +/- 2.4 cm(2) (hypertrophic cardiomyopathy) (P = not significant). After correction for body surface, annuli from patients with normal left ventricular function were smaller than annuli from patients with dilated cardiomyopathy (5.9 +/- 1.2 cm(2)/m(2) vs 7.7 +/- 1.0 cm(2)/m(2); P <.02). The change in area during the cardiac cycle showed significant differences: 23.8% +/- 5.1% (controls), 13.2% +/- 2.3% (dilated cardiomyopathy), and 32.4% +/- 7.6% (hypertrophic cardiomyopathy) (P <.001). Apico-basal motion was highest in controls, followed by those with hypertrophic obstructive and dilated cardiomyopathy (1.0 +/- 0.3 cm, 0.8 +/- 0.2 cm, 0.3 +/- 0.2 cm, respectively; P <.01). Visual inspection and Fourier analysis showed a consistent pattern of anteroseptal and posterolateral elevations of the annulus toward the left atrium. In conclusion, although area changes and apico-basal motion of the mitral annulus strongly depend on left ventricular systolic function, nonplanarity is a structural feature preserved throughout the cardiac cycle in all three groups.     

Features of mildly dilated congestive cardiomyopathy compared with idiopathic restrictive cardiomyopathy and typical dilated cardiomyopathy

Congestive cardiomyopathy was recognized in eight patients with only mildly dilated ventricles (an echocardiographic ventricular diastolic dimension index of less than 10% to 15% above the normal range) but with other features typical of end-stage congestive cardiomyopathy. Such patients with mildly dilated cardiomyopathy (MDCM) represented 5% of heart transplant recipients with cardiomyopathy, who were analyzed by us. The clinical, echocardiographic, and hemodynamic data, as well as the gross and microscopic pathologic findings of the hearts in this group were compared with similar data in five patients with idiopathic restrictive cardiomyopathy (IRCM) and 10 patients with typical dilated cardiomyopathy (DCM). Compared with IRCM and DCM, patients with MDCM had a higher incidence of familial cardiomyopathy (p less than 0.009). The echocardiographic features of patients with MDCM and DCM were virtually identical, showing globular hearts with predominant left ventricular dilation and diffuse poor left ventricular contraction. Patients with IRCM had marked atrial dilation but less abnormality of left ventricular size and contraction parameters. On the basis of echocardiographic data, patients with IRCM and MDCM could be well segregated. Cardiac index and light microscopic examinations were similar in the three groups. However, electron microscopy showed a lack of myofibrillar loss in patients with IRCM, little or no myofibrillar loss in those with MDCM, and almost total myofibrillar loss in those with DCM. Patients with MDCM have a high prevalence of familial cardiomyopathy. Absolute heart size and electron microscopic features of the MDCM group were intermediate between IRCM and DCM, but other clinical, echocardiographic and hemodynamic findings were similar to typical DCM.     

沙库巴曲缬沙坦对扩张型心肌病心力衰竭患者心肌损伤、左室功能及运动耐量的影响

目的 观察沙库巴曲缬沙坦对扩张型心肌病心力衰竭患者心肌损伤、左室功能及运动耐量的影响.方法 随机双盲选择我院收治的120例扩张型心肌病心力衰竭患者作为研究对象,按随机数字表法将其分为对照组和观察组,各60例.对照组采用常规抗心力衰竭方案治疗,观察组在常规方案基础上给予沙库巴曲缬沙坦治疗.比较两组的治疗效果.结果 治疗后,两组的心肌损伤指标(NT-proBNP、cTnI、sICAM-1、CgA)、左室功能指标(LVEF、LVEDV、LVESV、LAD)、运动耐量指标(6MWT、运动时间、运动代谢当量)均显著改善,且观察组优于对照组(P<0.05).结论 沙库巴曲缬沙坦应用于扩张型心肌病心力衰竭患者中可减轻其心肌损伤,改善左室功能,提高运动耐量,值得临床推广.     

Shock waves activate in vitro cultured progenitors and precursors of cardiac cell lineages from the human heart

Postischemic cardiomyopathy remains one of the disorders in urgent need of effective noninvasive therapy. It is currently accepted that the isolation, expansion and application of resident cardiac stem cells may hold therapeutic promise for the future. Recently, it has been demonstrated that shock waves (SW) could enhance the expression of vascular endothelial growth factor (VEGF) and its receptor, Flt-1. As the development of angiogenic noninvasive therapy is very important for future therapeutic strategies in cardiovascular diseases, we examined in vitro, the effects of SW treatment on adult resident cardiac primitive cells isolated from bioptic fragments of normal human hearts and from explanted pathologic hearts with postischemic cardiomyopathy. This study demonstrates that SW have positive influence on both the proliferation and the differentiation of cardiomyocytes, smooth muscle and endothelial cells precursors, with a more obvious effect being evident in the cells from normal heart than in those taken from pathologic hearts. Our results suggest that SW treatment could inhibit or retard the pathologic remodeling and functional degradation of the heart if applied during the early stages of heart failure.     

Right Ventricular endomyocardial biopsy: clinicopathologic correlates in 100 consecutive patients

The first 100 consecutive patients to undergo right ventricular endomyocardial biopsy at the Mayo Clinic were divided retrospectively into five groups, depending on the prebiopsy clinical diagnosis, and the biopsies were review histologically in a single-blind format. Group 1 consisted of 34 patients with a diagnosis of unexplained congestive heart failure and a dilated heart; of these, 4 (12%) had active myocarditis by biopsy. Of the six patients in group 2 with a clinical diagnosis of myocarditis, only one (17%) had biopsy evidence of inflammation, but two (33%) had changes that, in the clinical setting, were suggestive of cardiomyopathy. Group 3 consisted of 27 patients with dysrhythmia, syncope, or cardiac arrest but without congestive heart failure; of these, 4 (15%) had active myocarditis by biopsy, and 8 (30%) had changes that, with the clinical history, were consistent with cardiomyopathy. Group 4 included 19 patients with unexplained congestive heart failure and a nondilated heart; 4 (21%) had cardiac amyloid on biopsy. Group 5 was a diverse group of 14 patients with possible cardiac involvement by a known systemic disease; myocardial disease was documented by biopsy in 7 (50%). On the basis of these findings, we recommend endomyocardial biopsy (1) in patients with dilated cardiomyopathy in whom myocarditis is suspected, (2) in patients with the clinical diagnosis of active myocarditis in whom tissue documentation is indicated before treatment with anti-inflammatory or immunosuppressive drugs, (3) in patients with clinically unexplained life-threatening dysrhythmias in whom myocarditis or cardiomyopathy may be present, and (4) in patients with apparent hypertrophic or restrictive cardiomyopathy in whom cardiac amyloid may be present.     

Serum type III procollagen in dilated cardiomyopathy]

A radioimmunoassay study of procollagen type III end protein (PEP) was conducted in the serum of 11 patients with confirmed dilated cardiomyopathy (DCMP) and 9 patients with coronary heart disease. For DCMP patients PEP levels averaged 8.8 +/- 7.9 micrograms/l, for coronary patients 4.4 +/- 1.6 micrograms/l, in donors 1.7 +/- 1.4 micrograms/l. Thus, the difference between DCMP and coronary patients, donors appeared significant (p less than 0.05). PEP concentrations over 4.5 micrograms/l occurred in 54% of DCMP patients. Growing of PEP turned out most substantial in severe disease (circulatory failure stage IIB-III, pulmonary thromboembolism). Determination of PEP is thought valid for laboratory diagnosis of myocardial inflammation and fibrosis. The discussion covers possible causes and mechanisms underlying high production of PEP from the view point of impaired collagen production.     

Polymorphisms in CYP2D6 may predict methamphetamine related heart failure

Abstract

Background. Methamphetamine (METH) has been associated with a dilated cardiomyopathy. The first and rate-limiting step of metabolism is dependent on the polymorphic enzyme CYP2D6. Objectives. To evaluate if polymorphisms in CYP2D6 can be associated with the development of a methamphetamine-induced cardiomyopathy. Methods. We performed a prospective case-control pilot study. Cases were defined by a urinary drug screen positive for amphetamine and evidence of heart failure by beta natriuretic peptide (BNP) greater than 300 pg/ml and symptoms of heart failure. Controls were defined with urinary drug screens positive for amphetamines but without evidence of heart failure defined by a BNP lesser than 300 pg/ml or symptoms of heart failure. Exclusion criteria were less than 18 years or greater than 60 years of age, urinary toxicology screen positive for additional stimulants, known coronary artery disease (CAD) defined by greater than 50% stenosis on catheterization or previous myocardial infarction, known cardiomyopathy of alternative etiology or inability to provide consent. Patients underwent gas chromatography confirmation-mass spectroscopy for methamphetamine, genotyping of CYP2D6, limited echocardiography, and participated in a modified 2007 National Survey of Drug Use and Health Stimulant Survey. Genotype results were analyzed with traditional classifications and “Activity Scores”. Results. Fifty-six patients completed the study with 19 cases and 37 controls. There was no statistically significant difference in days of use in a month, age, gender, or ethnicity between cases and controls. While not statistically significant, age and days of use did trend higher in cases. CYP2D6 genotype demonstrated that the lower the activity score/poor metabolizer group had less heart failure than extensive metabolizers/higher activity score. However, it did not reach statistical significance. When adjusting for higher days of use, extensive metabolizers had the highest odds of developing a dilated cardiomyopathy. (OR: 2.33, 95% CI: 0.54–10.13). Echo findings in all cases showed reduced ejection fractions with a mean of 18.6% (range: 10–35%) and 70% had a dilated cardiomyopathy. No cardiomyopathies were seen in the controls. Mean ejection fraction was 56.75% (range: 45–70%). The odds ratio of having a dilated cardiomyopathy in extensive metabolizers was 1.62 (95% CI: 0.47–5.5). Conclusion. Our study demonstrates a trend that individuals with decreased metabolic activity were less likely to develop heart failure. While not statistically significant, a signal is present that extensive metabolizers may be at increased risk for the development of a cardiomyopathy.