Search PubMed⌕ Search

Biomedical subjects

A Schmermund

Publications and source records attributed to A Schmermund.

At least 19 recordsLinked to original sources
PubMed2006

Intraoperative coronary graft flow determination--does it have a prognostic value for midterm graft patency?

OBJECTIVE: To characterise the prognostic value of intraoperative ultrasonic graft flow determination during CABG for mid-term patency. METHODS: From 01/2000 to 08/2003 3146 CABG procedures were performed at our institution. Graft flow was determined in all patients. Lumen diameter was given in mm and a sclerosis score was applied for the target vessel. 100 of these patients (3.2%) underwent postoperative coronary angiography at a mean time interval of 8.0 +/- 0.5 months. RESULTS: In 100 patients, 114 LITA and 204 venous anastomoses were performed. At re-angiography 112 LITA (98%) and 174 venous (85%) anastomoses were patent. The amount of occluded LITA grafts was to low to perform statistical analyses. Mean graft flow of patent vein grafts was 48 +/- 2 ml/min vs. 32 +/- 4 ml/min in occluded vein grafts (p = 0.001). After multiple logistic regression analysis, only intraoperative vein graft flow was found to be a predictor for patency at mid-term (p = 0.005, odds ratio 0.97, 95% confidence interval (CI) from 0.95-0.99). No differences were found concerning sclerosis scores or vessel lumen between patent and occluded grafts. CONCLUSIONS: Significant differences concerning intraoperative graft flow were found between vein grafts patent or occluded at re-angiography. The predictive power of intraoperative vein graft flow for mid-term patency was confirmed by multiple logistic regression analysis.

Blood Flow Velocity↗
PubMed2006

Post-interventional homocysteine levels: failure as a predictive biomarker of in-stent restenosis.

OBJECTIVES: Purpose of our study was to determine if homocysteine plasma levels are related to the risk of in-stent restenosis after percutaneous coronary stent implantation in de novo lesions. BACKGROUND: The putative role of homocysteine as a predictive cardiovascular biomarker of coronary artery disease is well established. The impact of homocysteine levels in the development of in-stent restenosis, however, is controversially discussed. METHODS: A total of 177 patients with stable angina pectoris undergoing stent implantation in coronary de novo lesions were included. Laboratory determination comprised blood sample evaluation for homocysteine and other conventional risk factors before baseline coronary intervention and prior to six months control catheterization. Binary restenosis, late lumen loss, and late loss index after six months were assessed by quantitative coronary angiography. Endpoints included target lesion and target vessel failure, homocysteine levels as well as major adverse cardiac events. RESULTS: There was a significant correlation between the length of the implanted stent (p<0.006), the percentage of stenosis (p<0.003) and the pre-interventional luminal diameter (p<0.0001) with late loss index. Linear regression analysis demonstrated no significant impact of the initial or six months homocysteine levels on angiographic restenosis, late lumen loss, or late loss index. CONCLUSIONS: In contrast to homocysteine levels, luminal diameter, stent length and percentage of stenosis correlated with the appearance of restenosis. Taking our data into consideration, we hypothesise that homocysteine may not serve as a safe and independent biomarker of in-stent restenosis after a six months period following percutaneous coronary stenting.

Angioplasty, Balloon, Coronary↗
PubMed2006

Gadolinium as an alternative contrast agent during cardiac catheterization in patient with iodine-induced hyperthyroidism.

We report the first case of a male patient with iodine-induced hyperthyroidism and unstable angina pectoris in whom a diagnostic cardiac catheterization with gadolinium as contrast agent was chosen. The patient was hospitalized with an iodine-induced hyperthyroidism after angioplasty using an iodinated contrast agent. He presented with a continuous arrhythmia and unstable angina pectoris. A repeated cardiac catheterization using iodinated contrast agent was contraindicated. This case report shows that gadolinium is a useful alternative contrast agent for cardiac intervention in patients with iodine-induced hyperthyroidism.

Cardiac Catheterization↗
PubMed2005

Relevance of the NOS3 T-786C and G894T variants for cholinergic and adrenergic coronary vasomotor responses in man.

OBJECTIVE: We investigated the impact of the -786C allele at the promoter and the 894T allele in exon 7 of the gene encoding the endothelial nitric oxide synthase (NOS3) on coronary vasomotor responses to exogenous and endogenous stimuli. METHODS: In 47 individuals undergoing coronary angiography for chest pain, but without significant stenosis in the left anterior descending artery (LAD), nitroglycerine and acetylcholine were infused intracoronarily, and a cold pressor test (CPT) was performed. Coronary blood flow (CBF) in the LAD was calculated from quantitative coronary angiography and intracoronary Doppler measurements. Aortic and coronary sinus lactate levels were determined in 18 individuals. To analyze the impact of NOS3 genotypes, a logistic regression model was used. RESULTS: In response to acetylcholine (p = 0.002) and CPT (p = 0.015) CBF reduction was associated with homocygosity for the -786C allele. Myocardial lactate uptake was reversed into net lactate production in CC homocygotes. No independent effects of the G894T polymorphism were observed in the present study. Haplotype analysis revealed a significant linkage disequilibrium between both polymorphisms (p < 0.001). CONCLUSIONS: Our findings suggest a pathophysiologically relevant role for the T-786C polymorphism in human coronary vasomotion. The observed linkage disequilibrium between both NOS3 genotypes deserves further research in future studies.

Acetylcholine↗
PubMed2005

[Value of coronary artery calcium measurements in primary prevention].

Frequently, myocardial infarction or sudden coronary death are the index manifestations of coronary artery disease. In view of the high out-of-hospital mortality of acute myocardial infarction, medical care is unable to provide a benefit for many patients. Against this background, it is an important aim of measuring coronary calcium to identify asymptomatic subjects with an increased coronary risk who are likely to derive a benefit from risk-modifying therapy. Coronary calcium is a largely specific expression of coronary atherosclerosis and is correlated with overall coronary plaque volume. Due to the complex biology of the vessel wall and its ability to undergo compensatory remodelling, coronary calcium does not necessarily indicate significant stenosis. Coronary calcium is found in 70-80% of plaque ruptures but only in a minority of plaque erosions. It neither indicates a "vulnerable" nor a "stable" plaque. Six independent studies including healthy self-referred and physician-referred volunteers consistently describe the predictive value of coronary calcium with regard to coronary and cardiovascular clinical events. After adjusting for coronary risk factors, increased amounts of coronary calcium are associated with a 5- to 10-times elevated relative risk. Only recently have the first results from strictly unselected, population-based cohorts been reported which confirm the predictive ability of coronary calcium measurements. Concordant with actual guidelines issued by US-American and European expert panels, coronary calcium measurements can be used especially in patients with an indeterminate risk on the basis of clinical assessment and risk factor analysis. Substantially elevated coronary calcium scores provide a rationale for intensified risk-modifying therapy. This is also true for elderly patients in whom the established risk factors lose some of their predictive power. The use of coronary calcium measurements in self-referred patients or as a primary means for risk stratification is not encouraged.

Calcinosis↗
PubMed2005

Baseline recruitment and analyses of nonresponse of the Heinz Nixdorf Recall Study: identifiability of phone numbers as the major determinant of response.

The Heinz Nixdorf Recall Study is an ongoing population-based prospective cardiovascular cohort study of the Ruhr area in Germany. This paper focuses on the recruitment strategy and its response results including a comparison of participants of the baseline examination with nonparticipants. Random samples of the general population were drawn from residents' registration offices including men and women aged 45-74 years. We used a multimode contact approach including an invitational letter, a maximum of two reminder letters and phone calls for the recruitment of study subjects. Nonparticipants were asked to fill in a short questionnaire. We calculated proportions of response, contact, cooperation and recruitment efficacy to characterize the participation. Overall, 4487 eligible subjects participated in our study. Although the elderly (65-75 years) had the highest contact proportion, the cooperation proportion was the lowest among both men and women. The recruitment efficacy proportion was highest among subjects aged 55-64 years. The identifiability of the phone number of study subjects was an important determinant of response. The recruitment efficacy proportion among subjects without an identified phone number was 11.4% as compared to 65.3% among subjects with an identified phone number. The majority of subjects agreed to participate after one invitational letter only (52.6%). A second reminding letter contributed only very few participants to the study. Nonparticipants were more often current smokers than participants and less often belonged to the highest social class. Living in a regular relationship with a partner was more often reported among participants than nonparticipants.

Age Factors↗
PubMed2005

Resistant hypertension in patients with chronic aortic dissection.

Strict blood pressure control is pivotal in the management of patients with aortic dissection (AD), but is frequently difficult to achieve. We determined antihypertensive medical therapy and levels of blood pressure (BP) control in 40 patients with chronic AD. Patient charts were reviewed for clinical variables, serial BP measurements, and antihypertensive drug therapy. Patients were divided into two groups: patients in group 1 had effective BP control (<135/80 mmHg), patients in group 2 had resistant hypertension (BP>/=135/80 mmHg despite prescription of at least three antihypertensive drugs). Overall, systolic BP (SBP) was 130+/-20 mmHg, and diastolic BP (DBP) was 72+/-13 mmHg. Patients received a median of 4 (1-6) antihypertensive drugs. beta-blockers were used in 38/40 (95%) patients. Effective BP control was achieved in 24/40 (60%) patients (group 1), while 16/40 (40%) patients had resistant hypertension (group 2) despite receiving significantly more antihypertensive drugs (5 [4-6] vs 4 [1-5], P=0.001). Mean SBP was 116+/-9 (101-132) mmHg in group 1 and 151+/-13 (137-181) mmHg in group 2 (P<0.001); there was no difference in DBP. Group 2 patients had a significantly higher body mass index and were younger than patients in group 1. In conclusion, in the majority of patients with chronic AD, effective BP control can be achieved, but usually requires the combination of multiple antihypertensive drugs. However, in a significant proportion of patients (40%), who appear to be younger and more obese, medical therapy fails to achieve effective BP control despite use of a multiple drug regimen.

Adrenergic alpha-Antagonists↗
PubMed2004

Prognostic value of electron-beam computed tomography-derived coronary calcium scores compared with clinical parameters in patients evaluated for coronary artery disease. Prognostic value of EBCT in symptomatic patients.

OBJECTIVE: The electron-beam computed tomography-(EBCT-)derived calcium score provides a measure of coronary atherosclerotic plaque disease which may allow for more precise risk stratification in symptomatic patients. However, it remains unclear if EBCT can add prognostic information compared with the clinical information derived from risk factor assessment, exercise stress testing, and coronary angiography. METHODS AND RESULTS: A cohort of 300 consecutive patients with recent (<3 months) onset of symptoms was retrospectively identified who were examined for possible coronary artery disease (CAD) and who all underwent EBCT. Successful follow-up after 3.5 years was obtained in 255 (85%) patients whose mean age at baseline was 58+/-11 years (n = 181 (71%), males). Four clinical categories with increasing evidence of CAD were constructed on the basis of risk factor assessment, exercise stress testing, coronary angiographic anatomy, and coronary revascularization at baseline. During follow-up, major adverse cardiac events (MACE: myocardial infarction, cardiac death, revascularization) were observed in 40 (16%) patients, including myocardial infarction and cardiac death in 5 patients. The 4 clinical categories were highly predictive of MACE, with a relative risk estimate of 28.3 (95% CI, 6.7-119.1) in the upper vs. the reference category. In univariate analysis, the relative risk estimate of MACE associated with a calcium score > or =100 was 12.0 (95% CI, 4.7-30.6). After adjustment for the clinical categories and for age, this estimate decreased in multivariate analysis, but remained predictive at 4.4 (95% CI, 1.5-12.6). CONCLUSION: In patients with first-time evaluation of possible CAD, EBCT-derived coronary calcium is suggested to provide for independent and additional information compared with the clinically available information.

Adult↗
PubMed2004

Insulin sensitivity and coronary vasoreactivity: insulin sensitivity relates to adenosine-stimulated coronary flow response in human subjects.

OBJECTIVE: Diabetes is associated with coronary microvasculature abnormalities and impaired coronary flow reserve (CFR). CFR is the ratio of coronary flow under maximal vasodilation to basal flow and is a measure for coronary vasoreactivity. Insulin resistance is the central defect in the development of type 2 diabetes, preceding its onset by 10-20 years. Thus, the relationship between insulin sensitivity and CFR in nondiabetic subjects is particularly interesting. The aim of the study was to investigate this relationship. DESIGN: Cross-sectional study. PATIENTS: The study population consisted of 18 nondiabetic subjects without coronary artery stenosis on coronary angiography. We excluded patients with structural heart disease or with conditions affecting CFR or insulin sensitivity such as low density lipoprotein (LDL)-cholesterol > or = 4.14 mmol/l, smoking, hypertension or obesity with a body mass index (BMI) > 28 kg/m(2). MEASUREMENTS AND RESULTS: CFR was 3.1 +/- 0.8 (range 1.7-4.8), as assessed by intracoronary Doppler measurements in the left anterior descending coronary arteries after adenosine stimulation. Intravascular ultrasound revealed zero to moderate coronary atherosclerotic changes. Whole-body insulin sensitivity (M-value) was 7.5 +/- 2.9 mg/kg/min (range 2.2-12.6), as assessed by the hyperinsulinaemic-euglycaemic clamp test. Subjects with low CFR (< 3.0) had a significantly lower M-value than subjects with normal CFR (> 3.0) (6.0 +/- 2.5 vs. 9.0 +/- 2.5 mg/kg/min, P = 0.021). Univariate linear regression demonstrated a strong correlation between CFR and M-value (r = 0.76, P < 0.001). In multiple regression analysis, the significant association of CFR with M-value was independent of potential confounders (sex, age, BMI, LDL-cholesterol and plaque burden on intravascular ultrasound). Bootstrap analysis corroborated this finding. CONCLUSIONS: Whole-body insulin sensitivity relates to coronary vasoreactivity. Across a wide range of both insulin sensitivity and coronary flow reserve from markedly abnormal to normal values, an increase in insulin sensitivity appears to be associated with an increase in coronary flow reserve. Insulin resistance is therefore associated with coronary microvasculature abnormalities in nondiabetics.

Adenosine↗
PubMed2003

Treatment of arteriosclerosis.

Summary. Arteriosclerotic disease develops over the course of several decades. Currently, a number of therapies are at hand to effectively stop this process and avoid complications of arteriosclerosis. Among the non-pharmacologic options, a balanced diet and physical activity predominate. A modern dietary plan offers a variety of tasty servings rich in fresh fruit and vegetables, cereals, fish, and poly-unsaturated fatty acids. The value of regular physical activity is demonstrated by the finding that an increase in exercise capacity ("cardiorespiratory fitness") by only one metabolic equivalent already reduces cardiovascular risk by 20-25 %. Regarding pharmacologic therapy, convincing data are available for cholesterol synthase inhibitors ("statins"), some substances which influence the renin-angiotensin system (such as ramipril), and platelet aggregation inhibitors. Statins produce a 20 to 30 % reduction of cardiac death, myocardial infarction, and stroke. In patients with increased cardiovascular risk, the beneficial action of statins is also evident in subjects with low baseline cholesterol values. Apart from the cholesterol-lowering effects, anti-inflammatory and other vasoprotective mechanisms are involved. The angiotensin-converting enzyme inhibitor ramipril has demonstrated that even independent of blood-pressure lowering, cardiovascular events (cardiac death, myocardial infarction, stroke) are substantially reduced in high-risk patients. The effect is in the same order as that of statins. In patients with left-ventricular hypertrophy, the angiotensin-receptor antagonist losartan produces a notable reduction in stroke, independent of its blood-pressure lowering action. Finally, the platelet aggregation inhibitors aspirin and clopidogrel have proven benefit in secondary prevention and, in the case of aspirin, also in primary prevention in cardiovascular high-risk patients. The anti-arteriosclerotic properties of other substances are actively investigated, including calcium channel blockers, betablockers, and novel drug classes. From the medical point of view, a broader use of the well-proven and effective therapies of arteriosclerosis and its complications is clearly warranted.

Arteriosclerosis↗
PubMed2003

[Prognostic value of noninvasive coronary plaque burden quantification in patients with risk factors].

Non-invasive quantitative indices of atherosclerosis are promising new parameters for an improved prognostic stratification of patients with risk factors that aim at individualized risk factor assessment and modification. In a recently published ACC/AHA consensus document, further data on the diagnostic and prognostic value of coronary calcified plaque quantification were strongly encouraged prior to its use in the general population. In this present work we summarize data published since, which contribute significantly to the prognostic value of fast CT-based noninvasive coronary calcified plaque quantification. It is a measure of atherosclerostic disease activity and is hence an index for the likelihood of future cardiovascular events. Current data indicate that noninvasive quantification of coronary atherosclerosis has incremental prognostic value beyond conventional single risk factor assessment. However, it is not clear yet whether it has a significant value beyond quantitative combined risk assessment using complex risk prediction models such as Framingham charts. Results from ongoing prospective trials such as the MESA study in the US and the Heinz Nixdorf Recall study in Germany will clarify some of the pending issues. In addition, it is still unclear, at what stage of the disease process, which of the available imaging tools will provide optimal diagnostic and prognostic value for the individual patient.

Adult↗
PubMed2003

[Detection of coronary calcifications by electron beam tomography and multislice spiral CT: clinical relevance].

Coronary calcifications can be detected and quantified using electron beam tomography (EBT) or newer generation multi-slice spiral CT (MSCT) scanners. An abundance of data has been acquired by EBT. It could be shown that the amount of coronary calcium correlates to the coronary plaque burden. The detection of coronary calcium with CT imaging methods therefore provides a unique opportunity to detect and quantify coronary atherosclerosis in a subclinical stage. Consequently, the presence and amount of coronary calcium has been shown to be indicative for an increased coronary event risk in symptomatic and asymptomatic individuals. Several clinical studies found a predictive value that was superior to conventional risk factors. Clinically, the use of coronary calcification assessment may therefore be beneficial in patients who, based on traditional risk factors, seem to be at "intermediate risk" for coronary events (10-year event risk 10-20%) in order to decide on the aggressiveness of risk factor modification. The role of coronary calcium quantification to monitor the progression of disease has not been clarified yet. Large, ongoing trials will provide further data as to the relative merit of coronary calcium assessment for risk stratification and will help to more clearly define its clinical role. The relationship between coronary calcium and coronary stenoses is more complex. While the absence of coronary calcifications makes significant coronary stenoses unlikely, even large amounts of coronary calcium do not necessarily indicate the presence of coronary artery stenoses. Pronounced coronary calcifications as an isolated finding should therefore not be the motivation for invasive diagnostic procedures in the absence of other evidence of ischemic heart disease.

Calcinosis↗
PubMed2002

Tei-Index in coronary artery disease--validation in patients with overall cardiac and isolated diastolic dysfunction.

BACKGROUND: The index "isovolumic contraction time and isovolumic relaxation time divided by ejection time" ("Tei-Index") has been demonstrated to provide useful information about disease severity and prognosis in patients with dilated cardiomyopathy and cardiac amyloidosis. In patients with coronary artery disease (CAD), the diagnostic utility of this index is unclear. We attempted to validate the Tei-Index in CAD patients with overall cardiac or isolated diastolic dysfunction. METHODS AND RESULTS: Sixty subjects were included who underwent left heart catheterization for invasive measurement of left ventricular end-diastolic pressure (LVEDP): 20 symptomatic CAD patients with overall cardiac dysfunction (defined by a LV ejection fraction (EF) < 45% (mean 27 +/- 8%) and a LVEDP > or = 16 mmHg, (mean 22 +/- 6 mmHg), NYHA class 2.7 +/- 0.4, OCD group), 29 symptomatic CAD patients with isolated diastolic dysfunction (defined by an EF > 45% (mean 55 +/- 8%), a normal end-diastolic diameter index (mean 2.8 +/- 0.4 cm/m2) and a LVEDP > or = 16 mmHg (mean 22 +/- 6 mmHg), NYHA class 2.3 +/- 0.4, IDD group) and 11 asymptomatic control subjects (EF 65 +/- 9%, LVEDP 11 +/- 4 mmHg, CON group). After conventional 2-D- and Doppler echocardiographic examination, the Tei-Index was obtained. The Tei-Index was easily and reproducibly measured in all study subjects. In the OCD group, isovolumic contraction time was prolonged and ejection time was shortened in comparison to the CON group, resulting in a significantly increased Tei-Index (0.71 +/- 0.28 vs 0.40 +/- 0.11, p < 0.01). In the IDD group, isovolumic relaxation time was prolonged and isovolumic contraction time was shortened in comparison to controls, resulting in a largely unchanged Tei-Index (0.45 +/- 0.14, p = ns). Receiver operating characteristic curve analysis for the Tei-Index yielded an area under the curve of 0.92 +/- 0.04 for separating patients with vs without OCD. Using a Tei-Index > 0.49 as a cut-off, OCD patients were identified with a sensitivity of 96% and a specificity of 86%. CONCLUSION: The Tei-Index is a valid and readily derived indicator of global cardiac dysfunction in CAD patients with impaired systolic and diastolic LV performance. The use of this index seems to be limited in CAD patients with primary diastolic dysfunction.

Aged↗
PubMed2001

Unstable coronary plaque and its relation to coronary calcium.

Coronary calcium is intimately associated with coronary atherosclerotic plaque development. The use of electron-beam computed tomography (EBCT) for accurate quantitative measurements has led to an increased interest in understanding the clinical importance of coronary calcium, particularly in terms of the ability to identify unstable coronary plaques that underlie the clinical acute coronary syndromes. Histopathologic studies have demonstrated that calcium is a frequent feature of ruptured plaques, but the presence or absence of calcium does not allow for reliable distinction between unstable versus stable plaques. This issue is complicated by the lack of a prospective definition for "unstable." Plaque rupture is sometimes found in apparently healthy subjects and in patients with clinically stable disease. Coronary atherosclerosis is a coronary systemic disease process. Imaging of coronary calcium, although unable to identify a localized unstable plaque, potentially can identify the more clinically pertinent "unstable patient." Almost all patients with a recent acute coronary syndrome have measurable coronary calcium because moderate-to-advanced coronary plaque disease is already present, although obstructive disease frequently is not. Prospective studies have demonstrated that extensive coronary calcium detected by EBCT is associated with a significantly increased incidence of subsequent myocardial infarction, need for revascularization, and coronary death. The incremental prognostic value of coronary calcium compared with that of risk factor assessment remains to be fully defined. The occurrence of an acute coronary syndrome is determined by many factors apart from the extent of atherosclerotic plaque disease. Large prospective trials in the general population are needed to define the subgroups that will benefit most from quantitative assessment of coronary calcium.

Aged↗
PubMed2001

[New concepts of primary prevention require rethinking].

The decline in cardiovascular mortality over the past decades is due to improved survival of patients with clinical events rather than to a declining incidence of these events. As a result, an increased prevalence of chronic coronary artery disease and especially congestive heart failure has been described. Further substantial reductions in coronary artery disease morbidity and mortality can only be anticipated if coronary artery disease is treated before the manifestation of clinical disease. Modern concepts of primary prevention incorporate an individualized approach to risk assessment. Medical history, physical examination, and established laboratory tests are the basic instruments which allow for quantitative risk assessment. Tables and simplified algorithms derived from large clinical trials enable the calculation of intermediate and long-term ("life-time") probability of cardiac events. In this setting of quantitative risk assessment, the importance of some risk factors is increasingly recognized, namely diabetes. Noninvasive diagnostic testing is used to detect preclinical atherosclerotic plaque disease. Direct imaging of coronary and peripheral arteries, the ankle-brachial index, and measurements of C-reactive protein represent novel methods which have become available for further risk stratification. Because they consider the pathophysiology of atherosclerosis and coronary artery disease, these methods may facilitate decision-making regarding preventive treatment in patients who have an intermediate risk on the basis of the traditional risk factors. The modern concept of primary prevention is aimed at identifying subjects whose risk is similarly high as that of patients with clinically established cardiovascular disease. These subjects can then be treated efficiently, and the strict distinction between primary and secondary prevention is blurred.

Coronary Artery Disease↗