[Stem cell transfer in myocardial infarction].
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Biomedical subjects
Publications and source records attributed to A M Zeiher.
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OBJECTIVES AND METHODS: DETECT is a cross-sectional study of 55,518 unselected consecutive patients in 3188 representative primary care offices in Germany. In a random subset of 7519 patients, an extensive standardized laboratory program was undertaken. The study investigated the prevalence of cardiovascular disease, known risk factors (such as diabetes, hypertension and dyslipidemia and their co-morbid manifestation), as well as treatment patterns. The present analysis of the DETECT laboratory dataset focused on the prevalence and treatment of dyslipidemia in primary medical care in Germany. Coronary artery disease (CAD), risk categories and LDL-C target achievement rates were determined in the subset of 6815 patients according to the National Cholesterol Education Program (NCEP) ATP III Guidelines. RESULTS: Of all patients, 54.3% had dyslipidemia. Only 54.4% of the NCEP-classified dyslipidemic patients were diagnosed as 'dyslipidemic' by their physicians. Only 27% of all dyslipidemic patients (and 40.7% of the recognized dyslipidemic patients) were treated with lipid-lowering medications, and 11.1% of all dyslipidemic patients (41.4% of the patients treated with lipid-lowering drugs) achieved their LDL-C treatment goals. In conclusion, 80.3% of patients in the sample with dyslipidemia went undiagnosed, un-treated or under-treated.
During acute myocardial infarction, ischemia causes progressive loss of contractile tissue. Subsequently, structural changes lead to left ventricular remodeling finally resulting in the development of heart failure. In addition to an optimal reperfusion and pharmacologinal post-infarction therapy, increased neovascularization and regeneration of cardiomyocytes could reduce or even abolish the ongoing left ventricular remodeling processes within the infarct area. Experimental studies have demonstrated that transplantation of adult progenitor cells leads to increased neovascularization, reduced fibrosis and, therefore, increased left ventricular function after acute myocardial infarction. In contrast to current treatment strategies, progenitor cell therapy offers a new regenerative approach for myocardial tissue. Initial clinical studies have demonstrated, apart from safety and feasibility of intracoronary infusion of adult autologous progenitor cells, a significant improvement of left ventricular function, geometry and vascularization in patients with acute myocardial infarction receiving intracoronary infusion of progenitor cells. However, in patients with chronic ischemic cardiomyopathy, the improvement in contractility is less pronounced. Finally, whether intracoronary infusion of adult progenitor cells can also reduce morbidity and mortality due to heart failure, remains to be investigated.
BACKGROUND: Coronary microvascular dysfunction contributes to infarct extension and poor prognosis after an acute myocardial infarction (AMI). Recently, progenitor cell application has been demonstrated to improve neovascularization and myocardial function after experimental myocardial infarction. Therefore, we investigate coronary blood flow regulation in patients after AMI treated with intracoronary progenitor cell therapy. METHODS AND RESULTS: In the TOPCARE-AMI trial, patients received either bone marrow-derived or circulating progenitor cells into the infarct-related artery 3-7 days after AMI. The present substudy investigates in 40 patients coronary blood flow regulation at the time of progenitor cell therapy and at 4-month follow-up by i.c. Doppler in the infarct artery as well as a reference vessel. At the initial measurement, coronary flow reserve (CFR) was reduced in the infarct artery compared to the reference vessel (median 2.5 vs. 3.4, p<0.001). At 4-month follow-up, intracoronary progenitor cell therapy was associated with a normalization of CFR in the infarct artery (median 3.9 vs. reference vessel 3.8, p=0.15). CFR also improved in the reference vessel, but mechanisms were different: reference vessel increase in CFR was secondary to an increased basal vascular resistance, probably due to reduced need for hypercontractility. In contrast, in the infarct artery, adenosine-induced minimal vascular resistance profoundly decreased, indicating an increased maximal coronary vascular conductance capacity. In addition, in a non-randomized matched control group (n=8), minimal vascular resistance in the infarct artery was significantly elevated compared to progenitor cell treated patients 4 months after AMI (p=0.012). CONCLUSIONS: Intracoronary progenitor cell therapy after AMI is associated with complete restoration of coronary flow reserve due to a substantial improvement of maximal coronary vascular conductance capacity. The clinical importance of improved microcirculation by progenitor cell therapy in patients after AMI has to be established in further randomized trials.
Patients with diabetes mellitus are often not recognized in clinical routine, but also not well characterized in clinical trials. As a diagnostic approach it is recommended to test fasting glucose and glycosylated hemoglobin (HbA1c) in every patient with coronary artery disease (CAD). HbA1c, in addition, provides important prognostic information. Patients with diabetes mellitus do have an enhanced cardiovascular risk in all stages and during all kind of interventions of CAD. However, diabetes is not equal to diabetes; risk modifying factors such as HbA1c, concomitant diseases and medication have to be considered. Absolute benefit of pharmacological therapies is also enhanced in patients with diabetes compared to non-diabetics. However, statins or anti-hypertensive treatment seem to be even more effective in reducing cardiovascular events than pure control of glucose levels alone. During percutaneous interventions (PCI) glycoprotein IIb/IIIa-inhibitors reduce mortality in diabetics, an effect which may be partially also achieved by Clopidogrel. Glitazones reduce restenosis rates; however, clinical end point studies are still ongoing. After PCI, restenosis may be a predictor of mortality in patients with diabetes. Whether drug eluting stents, besides effectively reducing restenosis, may also reduce hard clinical events in patients with diabetes remains to be demonstrated. Current available studies comparing PCI with bypass are limited due to not considered factors (stenosis morphology), randomization bias, and faster progress of technology compared to study termination. During an acute coronary syndrome/myocardial infarction, hyperglycemia is an adverse prognostic marker. However, so far studies using glucose-insulin-potassium (GIK) infusion have not been convincingly demonstrate to be beneficial.
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DETECT is a nationwide epidemiological cross-sectional and longitudinal study program in a random probability sample of 3,795 primary care settings (response rate: 60.2%). Based on a target day total assessment of n=55,518 consecutive patients (RR 93.5%) in these settings all patients underwent standardized diagnostic assessment, using self-reporting, clinical interview and laboratory measures. DETECT aims at describing the point prevalence and comorbidity of coronary heart disease (CHD), hyperlipidaemia, arterial hypertension and diabetes mellitus and at identifying the behavioural, clinical, laboratory and psychological risk factors associated with these conditions. A random subset of patients (n=7,519) also completed an extensive standardized laboratory screening program and a 12-month follow-up investigation. Findings reveal a high prevalence of hypertension (36.3%), dyslipidaemia (29.1%), diabetes mellitus (14.6%) and CHD (12.4%) in primary care as well as their close association among each other. The study describes for the first time in greater detail the prevalence of specific disorders and the frequency of high-risk constellations in primary care and allows for the evaluation of various risk scores.
Initiation of effective cardiopulmonary resuscitation (CPR) at the earliest possible moment is the most important determinant of prognosis for prehospital cardiac arrest. The prognosis is essentially defined by two parameters: survival to hospital admission and survival to discharge. In connection with prehospital cardiac arrest, early defibrillation is particularly important, including the widespread availability of (semi)automatic defibrillators. Further aspects of CPR have recently received increased attention: on the one hand, changed study status regarding the use of antiarrhythmic agents (especially amiodarone), on the other hand, administration of vasopressin during resuscitation, and finally, the efficacy of mild hypothermia following prehospital cardiac arrest. These aspects represent the main subject of the present overview, which also addresses the latest revision of the International Liaison Committee on Resuscitation (ILCOR) guidelines on CPR that resulted in corresponding changes in the European Resuscitation Council (ERC) guidelines.
OBJECTIVE: Enhanced expression of CXCL16 has been demonstrated in atherosclerotic plaques and several properties have been attributed to CXCL16 that could influence the atherosclerotic process. CXCL16 exists in transmembrane and soluble forms. The transmembrane form acts as a scavenger receptor for oxidised LDL whereas the soluble form acts a chemoattractant for mainly CD8+ T cells. In addition, the soluble form of CXCL16 influences human aortic smooth muscle cell proliferation in vitro. In the present work, a human molecular genetic approach employing a common polymorphism within exon 4 of CXCL16 (181 Ala>Val) was used to investigate whether CXCL16 may be involved in the development of coronary artery disease. The polymorphism is located within the spacer region between the chemokine and transmembrane region and potentially influences an Ala/Val cleavage site, a site commonly used for the release of chemokines by tumour necrosis factor-alpha converting enzyme. DESIGN AND SUBJECTS: We first genotyped 387 unselected survivors of a first myocardial infarction aged <60 years and 387 sex- and age-matched controls. A subset of patients (n = 236) was evaluated by quantitative coronary angiography. Secondly, a cohort of 468 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) with stent implantation was genotyped. RESULTS: No significant difference in allele frequency between patient and controls of the 181 A>V polymorphism was detected. However, the V-allele was associated with increased severity of coronary stenoses. Secondly, the V-allele was associated with smaller minimal luminal diameter in the coronary segment subjected to intervention in a second cohort of patients undergoing PTCA with stent implantation. CONCLUSIONS: The present work provides evidence that CXCL16 is involved in processes leading to enhanced stenosis in atherosclerotic coronary arteries.
OBJECTIVES: DETECT is an epidemiological study in primary care to examine (a) the prevalence rates and comorbidity of diabetes mellitus, hypertension, hyperlipidaemia and coronary heart disease (CHD), and associated conditions; (b) the frequency of behavioural and clinical risk factors for onset and progression; (c) the 12-month course and outcome; and (d) the met and unmet needs for these patients. METHODS: Three-stage, cross-sectional clinical-epidemiological study with a prospective-longitudinal component in a nationally representative sample of N = 3795 primary care settings [response rate (RR): 60.2%] and N = 55518 patients (RR: 95.5%). Patients completed a standardized assessment, including questionnaires for patients and the physician and diagnostic screening measures (i.e. blood pressure, heart rate, body mass index and waist circumference assessments). A subsample of patients (N = 7519) also completed a standardized laboratory screening program and was followed-up after 12 months. Data were weighted to adjust for non-response, regional distribution and attrition. RESULTS: (1) Doctors and patients sample can be regarded as representative for primary care settings in Germany. (2) The clinician-rated point prevalence of hypertension is highest (35.5%), followed by hyperlipidaemia (29.1%), diabetes (14.1%) and CHD (12.1%); prevalence rates of each disorder as well as their co-incidence rates increase markedly with age. (3) The vast majority (78%) of all patients revealed multiple (3+) behavioural and clinical risk factors. CONCLUSION: The findings of DETECT underline the considerable burden for primary care doctors in managing a highly morbid patient population, with predominantly complex risk factor constellations, in routine care. Our data provide, in unprecedented detail, a basis for calculating age-, gender- and risk-group-adjusted risk-factor profiles in routine care.
This review highlights established and more recently recognized risk factors for coronary heart disease (CHD) relevant for patients seen in primary care, emphasizing the key role of diabetes mellitus type 2. Recent trends in risk factor research as well as current methods of risk stratification, and new systemic markers are discussed. Beyond the need for more forceful public health strategies to improve early recognition and intervention, the necessity of an integrated comprehensive investigation of the overall characteristics of cardiovascular disease, especially in primary care patients as a prerequisite for future concerted actions is pointed out. Based on this, a large-scale epidemiological investigation focusing on CHD and diabetes in the primary care sector is suggested.
BACKGROUND: Experimental and initial clinical studies suggest that transplantation of circulating blood- (CPC) or bone marrow-derived (BMC) progenitor cells may beneficially affect postinfarction remodeling processes after acute myocardial infarction (AMI). To relate functional characteristics of the infused cells to quantitative measures of outcome at 4-month follow-up, we performed serial contrast-enhanced MRI and assessed the migratory capacity of the transplanted progenitor cells immediately before intracoronary infusion. METHODS AND RESULTS: In 28 patients with reperfused AMI receiving either BMCs or CPCs into the infarct artery 4.7+/-1.7 days after AMI, serial contrast-enhanced MRI performed initially and after 4 months revealed a significant increase in global ejection fraction (from 44+/-10% to 49+/-10%; P=0.003), a decrease in end-systolic volume (from 69+/-26 to 60+/-28 mL; P=0.003), and unchanged end-diastolic volumes (122+/-34 versus 117+/-37 mL; P=NS). Infarct size, measured as late enhancement (LE) volume, decreased significantly, from 46+/-32 to 37+/-28 mL (P<0.05). There was a significant correlation between the reduction in LE volume and global ejection fraction improvement. The migratory capacity of transplanted cells as assessed ex vivo toward a gradient of vascular endothelial growth factor for CPCs and stromal cell derived factor-1 for BMCs was closely correlated with the reduction of LE volume. By multivariate analysis, migratory capacity remained the most important independent predictor of infarct remodeling. CONCLUSIONS: Analysis of serial contrast-enhanced MRI suggests that intracoronary infusion of adult progenitor cells in patients with AMI beneficially affects postinfarction remodeling processes. The migratory capacity of the infused cells is a major determinant of infarct remodeling, disclosing a causal effect of progenitor cell therapy on regeneration enhancement.
UNLABELLED: The number of elderly patients with coronary heart disease is rapidly growing. Morbidity, related with PTCA is increased in elderly patients, presumably because of the more complex adverse baseline characteristics. However, it has not been firmly elucidated whether routine use of coronary stents is associated with a more favourable outcome in this population. Therefore, we investigated the influence of age on acute procedural success, rate of restenosis (quantitative coronary angiography) and major cardiovascular events (death/myocardial infarction [MI]) 6 months after intra-coronary stent implantation in 1306 patients. Patients were categorised into < 65 years (n = 709),65-75 years (n = 443) and >75 years (n= 154). RESULTS: Older patients had a higher amount of multivessel disease (p < 0.001) and a lower left ventricular ejection fraction (p < 0.001). Nevertheless, the rate of acute success and restenosis were comparable between the different age groups. In contrast, older patients had significantly more adverse clinical events during long-term followup. (Death/MI < 65 years 3.0%, 65-75 years 3.9%, > 75 years 7.8%, p = 0.02). However, by multivariate analysis age was no longer an independent predictor of adverse clinical events (p = 0.26), which were predominantly determined by coexisting impaired left ventricular function (p < 0.001). CONCLUSION: After proper judgement of the clinical situation, coronary stent implantation should be considered in selected elderly patients. Thus, advanced age as a solely factor should not be regarded as a contraindication for coronary stent implantation.
BACKGROUND: Restenosis after percutaneous coronary intervention (PCI) is a major problem affecting 15% to 30% of patients after stent placement. No oral agent has shown a beneficial effect on restenosis or on associated major adverse cardiovascular events. In limited trials, the oral agent tranilast has been shown to decrease the frequency of angiographic restenosis after PCI. METHODS AND RESULTS: In this double-blind, randomized, placebo-controlled trial of tranilast (300 and 450 mg BID for 1 or 3 months), 11 484 patients were enrolled. Enrollment and drug were initiated within 4 hours after successful PCI of at least 1 vessel. The primary end point was the first occurrence of death, myocardial infarction, or ischemia-driven target vessel revascularization within 9 months and was 15.8% in the placebo group and 15.5% to 16.1% in the tranilast groups (P=0.77 to 0.81). Myocardial infarction was the only component of major adverse cardiovascular events to show some evidence of a reduction with tranilast (450 mg BID for 3 months): 1.1% versus 1.8% with placebo (P=0.061 for intent-to-treat population). The primary reason for not completing treatment was > or =1 hepatic laboratory test abnormality (11.4% versus 0.2% with placebo, P<0.01). In the angiographic substudy composed of 2018 patients, minimal lumen diameter (MLD) was measured by quantitative coronary angiography. At follow-up, MLD was 1.76+/-0.77 mm in the placebo group, which was not different from MLD in the tranilast groups (1.72 to 1.78+/-0.76 to 80 mm, P=0.49 to 0.89). In a subset of these patients (n=1107), intravascular ultrasound was performed at follow-up. Plaque volume was not different between the placebo and tranilast groups (39.3 versus 37.5 to 46.1 mm(3), respectively; P=0.16 to 0.72). CONCLUSIONS: Tranilast does not improve the quantitative measures of restenosis (angiographic and intravascular ultrasound) or its clinical sequelae.
BACKGROUND: Anti-tumor necrosis factor (TNF)-alpha therapy with etanercept, a recombinant TNF receptor that binds to and functionally inactivates TNF-alpha, was shown to improve the functional status of patients with congestive heart failure (CHF). Because administration of TNF-alpha has been shown experimentally to depress endothelium-dependent relaxation, we hypothesized that TNF-alpha antagonism with etanercept might improve the depressed systemic endothelial vasodilator function, which importantly contributes to increased peripheral vascular resistance in patients with advanced CHF. METHODS AND RESULTS: Endothelium-dependent (acetylcholine, ACH; 10 to 50 microgram/min) and endothelium-independent (sodium nitroprusside, SNP; 2 to 8 microgram/min) forearm blood flow (FBF) responses were measured by venous occlusion plethysmography in 13 patients with documented CHF (New York Heart Association class III) before, 6 hours after, and 7 days after subcutaneous injection of a single dose of 25 mg etanercept. Maximum ACH-induced FBF increased significantly from 6.9+/-1.0 to 13.0+/-1.6 mL/min per 100 mL of forearm tissue (P<0.05) 6 hours after administration of etanercept and returned to 7.0+/-1.1 mL/min per 100 mL of forearm tissue after 7 days (P=NS), whereas SNP-induced FBF responses were not significantly affected. In contrast, FBF responses were not altered in control CHF patients, who did not receive etanercept (n=5). Etanercept-induced increases in ACH-mediated FBF were closely correlated with baseline TNF-alpha serum levels (r=0.66; P<0.02). CONCLUSIONS: The administration of etanercept profoundly improves systemic endothelial vasodilator capacity in patients with advanced heart failure, suggesting an important role of inflammatory mediators for impaired endothelial vasoreactivity in CHF. Improvement of systemic endothelial function might importantly contribute to the beneficial effects of etanercept on the functional status of patients with CHF.
BACKGROUND: Proinflammatory cytokines like tumor necrosis factor-alpha and oxidative stress induce apoptotic cell death in endothelial cells (ECs). Systemic inflammation and increased oxidative stress in congestive heart failure (CHF) coincide with enhanced EC apoptosis and the development of endothelial dysfunction. Therefore, we investigated the effects of antioxidative vitamin C therapy on EC apoptosis in CHF patients. METHODS AND RESULTS: Vitamin C dose dependently suppressed the induction of EC apoptosis by tumor necrosis factor-alpha and angiotensin II in vitro as assessed by DNA fragmentation, DAPI nuclear staining, and MTT viability assay. The antiapoptotic effect of vitamin C was associated with reduced cytochrome C release from mitochondria and the inhibition of caspase-9 activity. To assess EC protection by vitamin C in CHF patients, we prospectively randomized CHF patients in a double-blind trial to vitamin C treatment versus placebo. Vitamin C administration to CHF patients markedly reduced plasma levels of circulating apoptotic microparticles to 32+/-8% of baseline levels, whereas placebo had no effect (87+/-14%, P<0.005). In addition, vitamin C administration suppressed the proapoptotic activity on EC of the serum of CHF patients (P<0.001). CONCLUSIONS: Administration of vitamin C to CHF patients suppresses EC apoptosis in vivo, which might contribute to the established functional benefit of vitamin C supplementation on endothelial function.
Advanced aging leads to impaired endothelial NO synthesis and enhanced endothelial cell apoptosis; therefore, we investigated the sensitivity of aged endothelial cells toward apoptotic stimuli and determined the role of NO. Human umbilical vein endothelial cells (HUVECs) were cultured until 14th passage. In aged cells, oxLDL and tumor necrosis factor-alpha-induced apoptosis and caspase-3-like activity were significantly enhanced more than 3-fold compared with young cells (passage 3). Because NO contributes to protection against endothelial cell death via S-nitrosylation of caspases, we determined endothelial NO synthase (eNOS) protein expression and the content of S-nitrosylated proteins. Aged HUVECs showed significantly reduced eNOS expression (35+/-10%) and a decrease in the overall S-NO content (33+/-3%), suggesting that eNOS downregulation may be involved in age-dependent increase of apoptosis sensitivity. Indeed, eNOS knockout endothelial cells showed a significantly enhanced apoptosis induction. Exogenous NO donors abolished increased apoptosis and caspase-3-like activity. In contrast, the application of shear stress, which exerts a profound apoptosis inhibitory effect via upregulation of NO synthesis in young cells, failed to inhibit apoptosis in aged cells. Moreover, no upregulation of eNOS protein expression and S-NO content in response to shear stress was detected in aged cells. Overexpression of wild-type eNOS completely restored the antiapoptotic effect of shear stress, whereas only a partial inhibitory effect was detected under steady conditions. Strikingly, transfection of constitutively active phosphomimetic eNOS (S1177D) further abrogated apoptosis in aged HUVECs. Thus, aging of endothelial cells is associated with decreased NO synthesis and concomitantly increased sensitivity of apoptosis, which may contribute to functional impairment of the endothelial monolayer.
Nitric oxide (NO) plays an important role in the regulation of the functional integrity of the endothelium. The intracellular reaction of NO with reactive cysteine groups leads to the formation of S-nitrosothiols. To investigate the regulation of S-nitrosothiols in endothelial cells, we first analyzed the composition of the S-nitrosylated molecules in endothelial cells. Gel filtration revealed that more than 95% of the detected S-nitrosothiols had a molecular mass of more than 5000 Da. Moreover, inhibition of de novo synthesis of glutathione using N-butyl-sulfoximine did not diminish the overall cellular S-NO content suggesting that S-nitrosylated glutathione quantitatively plays only a minor role in endothelial cells. Having demonstrated that most of the S-nitrosothiols are proteins, we determined the regulation of the S-nitrosylation by pro-inflammatory and pro-atherogenic factors, such as TNFalpha and mildly oxidized low density lipoprotein (oxLDL). TNFalpha and oxLDL induced denitrosylation of various proteins as assessed by Saville-Griess assay, by immunostaining with an anti-S-nitrosocysteine antibody, and by a Western blot approach. Furthermore, the caspase-3 p17 subunit, which has previously been shown to be S-nitrosylated and thereby inhibited, was denitrosylated by TNFalpha treatment suggesting that S-nitrosylation and denitrosylation are important regulatory mechanisms in endothelial cells contributing to the integrity of the endothelial cell monolayer.