Christoph Hanefeld

Risk factors and myocardial infarction in patients with obstructive sleep apnea: impact of β2-adrenergic receptor polymorphisms

BackgroundThe increased sympathetic nervous activity in patients with obstructive sleep apnea (OSA) is largely responsible for the high prevalence of arterial hypertension, and it is suggested to adversely affect triglyceride and high-density lipoprotein (HDL) cholesterol levels in these patients. The functionally relevant polymorphisms of the β2-adrenergic receptor (Arg-47Cys/Arg16Gly and Gln27Glu) have been shown to exert modifying effects on these risk factors in previous studies, but results are inconsistent.MethodsWe investigated a group of 429 patients (55 ± 10.7 years; 361 men, 68 women) with moderate to severe obstructive sleep apnea (apnea/hypopnea index (AHI) 29.1 ± 23.1/h) and, on average, a high cardiovascular risk profile (body mass index 31.1 ± 5.6, with hypertension in 60.1%, dyslipidemia in 49.2%, and diabetes in 17.2% of patients). We typed the β2-adrenergic receptor polymorphisms and investigated the five most frequent haplotypes for their modifying effects on OSA-induced changes in blood pressure, heart rate, and lipid levels. The prevalence of cardiovascular risk factors and coronary heart disease (n = 55, 12.8%) and survived myocardial infarction (n = 27, 6.3%) were compared between the genotypes and haplotypes.ResultsMultivariate linear/logistic regressions revealed a significant and independent (from BMI, age, sex, presence of diabetes, use of antidiabetic, lipid-lowering, and antihypertensive medication) influence of AHI on daytime systolic and diastolic blood pressure, heart rate, prevalence of hypertension, and triglyceride and HDL levels. The β2-adrenergic receptor genotypes and haplotypes showed no modifying effects on these relationships or on the prevalence of dyslipidemia, diabetes, and coronary heart disease, yet, for all three polymorphisms, heterozygous carriers had a significantly lower relative risk for myocardial infarction (Arg-47Cys: n = 195, odds ratio (OR) = 0.32, P = 0.012; Arg16Gly: n = 197, OR = 0.39, P = 0.031; Gln27Glu: OR = 0.37, P = 0.023). Carriers of the most frequent haplotype (n = 113) (haplotype 1; heterozygous for all three polymorphisms) showed a five-fold lower prevalence of survived myocardial infarction (OR = 0.21, P = 0.023).ConclusionOur study showed no significant modifying effect of the functionally relevant β2-adrenergic receptor polymorphisms on OSA-induced blood pressure, heart rate, or lipid changes. Nevertheless, heterozygosity of these polymorphisms is associated with a lower prevalence of survived myocardial infarction in this group with, on average, a high cardiovascular risk profile.

Circulating Endothelial Microparticles Correlate Inversely With Endothelial Function in Patients With Ischemic Left Ventricular Dysfunction

BACKGROUND Bone-marrow derived endothelial progenitor cells (CD34+ and VEGFR2+ KDR+ EPC) and endothelial-derived microparticles (CD 31+Annexin V+, EMP; indicator for endothelial apoptosis) were examined in the peripheral blood of 35 male, clinically stable patients with 3-vessel coronary artery disease (CAD). The patients were divided in 2 groups, those with preserved or normal function (n = 17; EF 65 +/- 6%) and those with reduced left ventricular (LV) function (n = 18; EF 36 +/- 11%). METHODS AND RESULTS The number of circulating EPCs was decreased by 25% (P = .07) and the number of EMPs was increased by 109 % (P < .05) in patients with LV dysfunction compared with those with normal or preserved LV function. EPCs were positively correlated (r = 0.24 for patients with LV dysfunction and r = 0.28 for patients with preserved LV function) with endothelial function as assessed by flow-mediated vasodilatation. In contrast, EMPs were inversely correlated (r = -0.42 for patients with LV dysfunction and r = -0.49 for patients with preserved LV function). CONCLUSIONS CAD patients with significant LV dysfunction show an increased index of endothelial cell damage. This decrease (or lack of compensatory elevation) of EPCs may result in a reduced potential for repair and thus contribute at least in part to the pathogenesis of endothelial dysfunction.

Hormonal status modulates circulating endothelial progenitor cells

ObjectiveEndothelial progenitor cells (EPCs) may have an important role in vascular homeostasis and repair.MethodsWe examined the level of circulating EPCs in pre- (n = 22; mean age 28.7 years), and postmenopausal healthy females without (n = 30; mean age 61.6 years) or under current hormone replacement therapy (HRT) (n = 19; mean age 59.8 years).ResultsPremenopausal females had the highest level of circulating EPCs (0.147 ± 0.076‰ of polymorphnuclear cells). The level of EPCs was lowest in postmenopausal females (0.094 ± 0.058‰), and increased significantly with HRT on average by 25.5%. In addition, the proliferative capacity of circulating EPCs was assessed under cell culture conditions. This capacity was significantly increased in EPCs isolated from postmenopausal subjects under current HRT as compared to corresponding samples obtained from postmenopausal females without HRT.ConclusionsThis observation is in line with the hypothesis that the hormonal status in females modulates the cardiovascular risk and that circulating EPCs could be involved in this phenomenon.

Basic life support skills of high school students before and after cardiopulmonary resuscitation training: a longitudinal investigation

BackgroundImmediate bystander cardiopulmonary resuscitation (CPR) significantly improves survival after a sudden cardiopulmonary collapse. This study assessed the basic life support (BLS) knowledge and performance of high school students before and after CPR training.MethodsThis study included 132 teenagers (mean age 14.6 ± 1.4 years). Students completed a two-hour training course that provided theoretical background on sudden cardiac death (SCD) and a hands-on CPR tutorial. They were asked to perform BLS on a manikin to simulate an SCD scenario before the training. Afterwards, participants encountered the same scenario and completed a questionnaire for self-assessment of their pre- and post-training confidence. Four months later, we assessed the knowledge retention rate of the participants with a BLS performance score.ResultsBefore the training, 29.5% of students performed chest compressions as compared to 99.2% post-training (P < 0.05). At the four-month follow-up, 99% of students still performed correct chest compressions. The overall improvement, assessed by the BLS performance score, was also statistically significant (median of 4 and 10 pre- and post-training, respectively, P < 0.05). After the training, 99.2% stated that they felt confident about performing CPR, as compared to 26.9% (P < 0.05) before the training.ConclusionsBLS training in high school seems highly effective considering the minimal amount of previous knowledge the students possess. We observed significant improvement and a good retention rate four months after training. Increasing the number of trained students may minimize the reluctance to conduct bystander CPR and increase the number of positive outcomes after sudden cardiopulmonary collapse.

Successful treatment of recalcitrant cutaneous sarcoidosis with fumaric acid esters

BackgroundSarcoidosis is a multisystem disease of unknown origin characterized by the formation of noncaseating granulomas, in particular in the lungs, lymph nodes, eyes, and skin. Systemic treatment for cutaneous sarcoidosis can be used for large disfiguring lesions, generalized involvement, or recalcitrant lesions that did not respond to topical therapy.Case presentationsWe report three patients with recalcitrant cutaneous sarcoidosis who were treated with oral fumaric acid esters (FAE). Three female patients presented with cutaneous sarcoidosis that have proved to be refractory to various therapies, including corticosteroids and chloroquine. We treated the patients with FAE in tablet form using two formulations differing in strength (Fumaderm® initial, Fumaderm®). Dosage of FAE was performed according to the standard therapy regimen for psoriasis patients. After treatment with FAE (4–12 months), a complete clearance of skin lesions was achieved in the three patients. The side effects observed in this trial correspond to the well-known spectrum of adverse effects of FAE (flush, minor gastrointestinal complaints, lymphopenia).ConclusionsOn the basis of our findings FAE therapy seems to be a safe and effective regimen for patients with recalcitrant cutaneous sarcoidosis. Nevertheless further investigations are necessary to confirm our preliminary results.

The CYP2J2 G-50T polymorphism and myocardial infarction in patients with cardiovascular risk profile

BackgroundCytochrome P450 (CYP) enzyme 2J2, an epoxygenase predominantly expressed in the heart, metabolises arachidonic acid to biologically active eicosanoids. One of the CYP2J2 products, 11, 12-epoxyeicosatrienoic acid, has several vasoprotective effects. The CYP2J2-G-50T-promotor polymorphism decreases gene expression and is associated with coronary artery disease. This association supports the vascular protective role of CYP-derived eicosanoids in cardiovascular disease. In the present study, we investigated the influence of this polymorphism on survived myocardial infarction in two study groups of patients with on average high cardiovascular risk profile.MethodsThe CYP2J2 polymorphism was genotyped in two groups of patients that were collected with the same method of clinical data collection. Data from 512 patients with sleep apnoea (group: OSA) and on average high cardiovascular risk profile and from another 488 patients who were admitted for coronary angiography (CAR-group) were evaluated for a potential correlation of the CYP2J2 polymorphism G-50T and a history of myocardial infarction. The G-50T polymorphism of the CYP2J2 gene was genotyped by allele specific restriction and light cycler analysis.ResultsThe T-allele of the polymorphism was found in 111 (11.1%; CAR-group: N = 65, 13.3%; OSA: N = 46, 9.0%). 146 patients had a history of myocardial infarction (CAR: N = 120, 24.6%; OSA: N = 26, 5.1%). Cardiovascular risk factors were equally distributed between the different genotypes of the CYP2J2 G-50T polymorphism. In the total group of 1000 individuals, carriers of the T-allele had significantly more myocardial infarctions compared to carriers of the wild type (T/T or G/T: 21.6%; G/G: 13.7%; p = 0.026, odds ratio 1.73, 95%-CI [1.06–2.83]). In the multivariate logistic regression analysis the odds ratio for a history of myocardial infarction in carriers of the T-allele was 1.611, 95%-CI [0.957–2.731] but this trend was not significant (p = 0.073).ConclusionIn presence of other risk factors, the CYP2J2 G-50T failed to show a significant role in the development of myocardial infarction. However, since our result is close to the border of significance, this question should be clarified in larger, prospective studies in the future.

Plasma concentration of asymmetric dimethylarginine and the risk of coronary heart disease: rationale and design of the multicenter CARDIAC study

There is abundant evidence now that the endothelium plays a crucial role in the maintenance of vascular tone and structure. One of the major endothelium-derived vasoactive mediators is nitric oxide (NO). Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of NO synthase. ADMA inhibits vascular NO production at concentrations found in pathophysiological conditions; ADMA also causes local vasoconstriction when it is infused intra-arterially. ADMA is increased in plasma of humans with hypercholesterolemia, atherosclerosis, hypertension, chronic renal failure, and chronic heart failure. Increased ADMA levels are associated with reduced NO synthesis as assessed by impaired endothelium-dependent vasodilation. In several prospective and cross-sectional studies, ADMA evolved as a marker of cardiovascular risk in certain populations like hemodialysis patients, non-smoking men, or intensive-care patients. The CARDIAC study is a multicenter case-control study designed to address the hypothesis that ADMA may be a suitable and sensitive marker of cardiovascular risk in a large, unselected population of both sexes, and with a broad range of established cardiovascular risk factors. The population included in the CARDIAC study will be prospectively followed for a scheduled follow-up period of 4 years, and the data of the CARDIAC-PRO study will then provide definite evidence whether ADMA may be prospectively determined as a cardiovascular risk factor.

First-In-Man Experience With a New 7F Vascular Closure Device (EXOSEAL™): The 7F ECLIPSE Study

OBJECTIVE This feasibility study examined safety and effectiveness of the new EXOSEAL™ Vascular Closure Device (VCD) designed to promote hemostasis and early ambulation after percutaneous procedures. BACKGROUND Most VCDs currently approved by the United States FDA have been associated with significantly shorter time-to-hemostasis (TTH) and time-to-ambulation (TTA) compared to standard manual or mechanical compression, but their ease of use, patient comfort during deployment, and safety profiles are variable. METHODS Patients underwent diagnostic or interventional procedures using 7F introducer sheaths. Primary safety endpoint was the 30-day combined rate of access-related complications and primary effectiveness endpoints were TTH and TTA. RESULTS Sixty patients were enrolled prospectively (mean age 63.3 ± 11.3 year, 17% diabetics). Device and procedural success was achieved in 92% and 93%, respectively. Mean TTH and TTA was 3.2 ± 3.0 minutes and 3.0 ± 6.2 hours, respectively. No deaths or serious access-related adverse events occurred. A ≥6 cm access-site hematoma was the only adverse event, observed in 3 patients. CONCLUSIONS Use of the 7F EXOSEAL™ VCD was associated with short TTH and TTA, as well as low rates of procedural and 30-day access-related complications.

A Prospective, Single-Blind, Multicenter, Dose Escalation Study of Intracoronary iNOS Lipoplex (CAR-MP583) Gene Therapy for the Prevention of Restenosis in Patients with de novo or Restenotic Coronary Artery Lesion (REGENT I Extension)

Neointimal hyperplasia causing recurrent stenosis is a limitation of the clinical utility of percutaneous transluminal coronary interventions (PCI). Nitric oxide (NO) inhibits smooth muscle cell proliferation, platelet activation, and inflammatory responses, all of which have been implicated in the pathogenesis of restenosis. In animals, neointimal proliferation after balloon injury has been shown to be effectively reduced by gene transfer of the inducible NO synthase (iNOS). The primary objective of this first multicenter, prospective, single-blind, dose escalation study was to obtain safety and tolerability information of the iNOS lipoplex (CAR-MP583) gene therapy for reducing restenosis following PCI. Local coronary intramural CAR-MP583 delivery was achieved using the Infiltrator balloon catheter. A total of 30 patients were treated in the study (six patients, 0.5 μg; six patients, 2.0 μg; six patients, 5.0 μg; and 12 patients, 10 μg). There were no complications related to local application of CAR-MP583. In one patient, PCI procedure-related transient vessel occlusion occurred with consecutive troponin elevation. There were no signs of inflammatory responses or hepatic or renal toxicity. No dose relationship was seen with regard to adverse events across the dose groups. Thus, coronary intramural lipoplex-enhanced iNOS gene therapy during PCI is feasible and appears to be safe. These initial clinical results are encouraging to support further clinical research, in particular in conjunction with new local drug delivery technologies.

Dosimetric measurements in isolated human coronary arteries: comparison of commercially available iridium(192) with strontium/yttrium(90) emitters.

Background—Intravascular brachytherapy is being applied more and more in patients with coronary artery disease for the prevention of restenosis subsequent to balloon angioplasty, in particular after stent implantation. Several radiation sources (&bgr;- and &ggr;-emitters) are available in clinical routine. It was the purpose of this study to compare the radiation doses at the level of the adventitia in diseased and stented human coronary arteries for 192Ir and 90Sr/Y emitters in routine use. In contrast to previously published work, we performed dosimetry instead of calculating depth-dose distribution by use of the Monte Carlo system. Methods and Results—Postmortem calcified human coronary artery segments were stented and placed in an organ bath. Commercially available &ggr;-emitters (192Ir; Cordis Checkmate) and &bgr;-emitters (90Sr/Y; Novoste Beta-Cath) were used. Relative dose distributions along the adventitia were measured by a specially designed scintillation detector system. Whereas dose perturbations caused by stents and calcified plaque were negligible for the 192Ir source, radiation from the beta source was significantly impaired (as much as 40%) at the level of the adventitia (3.0-mm vessel diameter). Dose perturbation was clearly dependent on the extent and severity of calcification, less affected by stent material. Conclusions—Dose perturbation caused by calcified plaque and metallic stents is significant for &bgr;-sources. This dosimetric difference between &bgr;- and &ggr;-emitters in diseased coronary arteries should be considered when calculating doses in intravascular brachytherapy.