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Biomedical subjects

J E Muller

Publications and source records attributed to J E Muller.

At least 19 recordsLinked to original sources
PubMed2005

Effect of diabetes mellitus and its treatment on ventricular arrhythmias complicating acute myocardial infarction.

AIMS: To evaluate the effect of diabetes mellitus and its treatment on the risk of arrhythmias among early survivors of acute myocardial infarction. RESEARCH DESIGN AND METHOD: The Onset Study was conducted in 64 US medical centres. Between August 1989 and September 1996, 3882 patients were interviewed after having an acute myocardial infarction. We used logistic regression models to examine the association of diabetes and its treatment with the risk of ventricular arrhythmia after adjustment for age, gender, hypertension, thrombolytic therapy, smoking, obesity, cardiac medicines and congestive heart failure. RESULTS: During the index hospitalization, patients with diabetes (n=814) were less likely to develop ventricular arrhythmias than patients without diabetes (6.8 vs. 13.3%, P<0.001). The risk of ventricular arrhythmia in patients treated with first generation sulphonylureas or diet alone was similar to patients without diabetes (OR=0.91; 95% CI, 0.39-2.15, and 0.76; 95% CI, 0.46-1.26, respectively). However, compared with patients without diabetes, the adjusted odds ratio (OR) for ventricular arrhythmias was lower among patients treated with insulin or patients treated with second generation sulphonylureas (OR=0.54, 95% CI 0.32-0.92; OR=0.45, 95% CI 0.27-0.75, respectively). CONCLUSIONS: Compared with patients without diabetes, the risk of ventricular arrhythmias complicating acute myocardial infarction is lower in patients with diabetes treated with second generation sulphonylureas or insulin, but not in those treated with first generation sulphonylureas or diet alone. This suggests that differences in the mechanism of action of different sulphonylureas may result in clinically relevant differences in arrhythmic risk.

Acute Disease↗
PubMed2004

Suicide attempts in an African schizophrenia population: an assessment of demographic risk factors.

This study investigated demographic variables, including affected sibling pair status, as risk factors for suicidal behavior in schizophrenia patients of African (Xhosa) descent. Xhosa subjects with schizophrenia were interviewed with the Diagnostic Interview for Genetic Studies (DIGS) and then stratified into two groups: those with ( n = 90) and those without ( n = 364) a history of previous suicide attempts. Demographic parameters (including gender, age, and social circumstances, sib ship) were then compared across these groups. Demographic predictors of suicide included sib ship status ( p = 0.038; OR = 1.7) and age of onset of illness ( p = 0.008; OR = 2.5). On further analysis of suicide in siblings, only a minority of sib pairs was found to be concordant for a lifetime history of suicide attempts (3%). These findings raise the possibility that affected sib pair status may be protective in nature. Given the counter-intuitive nature of this finding, further work is needed to replicate it, and to explore possible underlying mechanisms.

Adolescent↗
PubMed2001

Alcohol consumption and hemostatic factors: analysis of the Framingham Offspring cohort.

BACKGROUND: Moderate alcohol consumers have lower rates of cardiovascular disease than abstainers. One proposed mechanism is a beneficial effect on hemostatic parameters, but previous studies have provided conflicting results. METHODS AND RESULTS: We measured levels of fibrinogen, plasma viscosity, von Willebrand factor, factor VII, plasminogen activator inhibitor antigen-1, and tissue plasminogen activator antigen in a cross-sectional analysis of 3223 adults free of cardiovascular disease enrolled in the Framingham Offspring Study. We assessed their alcohol consumption with a standardized questionnaire. Light-to-moderate alcohol consumption was associated with lower levels of fibrinogen, plasma viscosity, von Willebrand factor, and factor VII. This association was most pronounced for consumers of 3 to 7 drinks weekly for viscosity and 7 to 21 drinks weekly for the other hemostatic measures. Alcohol intake of 7 to 21 drinks weekly or more was associated with impaired fibrinolytic potential, reflected by higher levels of plasminogen activator inhibitor antigen-1 and tissue plasminogen activator antigen. Wine drinkers had lower plasminogen activator inhibitor antigen-1 levels than other drinkers, particularly at 3 to 21 drinks weekly, but beverage type did not otherwise consistently affect the results. CONCLUSIONS: Light-to-moderate alcohol consumption is associated with lower levels of coagulatory factors, but higher intake is associated with impaired fibrinolytic potential. These findings are consistent with the hypothesis that a balance between hemostatic and fibrinolytic activity may contribute to the complex relation of alcohol use with coronary heart disease.

Alcohol Drinking↗
PubMed2001

Platelet glycoprotein IIIa Pl(a) polymorphism, fibrinogen, and platelet aggregability: The Framingham Heart Study.

BACKGROUND: Recent data suggest that the Pl(A2) allele of the platelet glycoprotein IIIa receptor may be a genetic risk factor for cardiovascular disease. We previously reported that the Pl(A2) allele was associated with increased platelet aggregability, as indicated by lower epinephrine threshold concentrations. Paradoxically, however, it has been reported that Pl(A2)-positive platelets have reduced fibrinogen binding. Because fibrinogen mediates platelet aggregability, we hypothesized that plasma fibrinogen levels may interact with Pl(A) genotype in modulating platelet aggregability. Methods and Results-- Glycoprotein IIIa Pl(A) genotype, fibrinogen level, and platelet aggregability were ascertained in 1340 subjects enrolled into the Framingham Offspring Study. Platelet aggregability was evaluated by the Born method. Higher fibrinogen levels were associated with increased epinephrine-induced aggregation (P=0.002) and a trend for ADP-induced aggregation (P=0.07). The fibrinogen effect was genotype specific, however, in that the increase in platelet aggregability with higher fibrinogen was present for the Pl(A1/A1) genotype (P=0.0005 and P=0.03 for epinephrine- and ADP-induced aggregation, respectively) but not for the Pl(A2)-positive genotype (P>0.90). CONCLUSION: Higher fibrinogen levels were associated with increased platelet aggregability. However, the association between fibrinogen and platelet aggregability was genotype specific. This interaction may be responsible for the conflicting findings regarding Pl(A) genotype and platelet aggregability. Further study of this gene-environment interaction may provide insight into cardiovascular disease risk.

Adenosine Diphosphate↗
PubMed2001

Triggering myocardial infarction by marijuana.

BACKGROUND: Marijuana use in the age group prone to coronary artery disease is higher than it was in the past. Smoking marijuana is known to have hemodynamic consequences, including a dose-dependent increase in heart rate, supine hypertension, and postural hypotension; however, whether it can trigger the onset of myocardial infarction is unknown. METHODS AND RESULTS: In the Determinants of Myocardial Infarction Onset Study, we interviewed 3882 patients (1258 women) with acute myocardial infarction an average of 4 days after infarction onset. We used the case-crossover study design to compare the reported use of marijuana in the hour preceding symptoms of myocardial infarction onset to its expected frequency using self-matched control data. Of the 3882 patients, 124 (3.2%) reported smoking marijuana in the prior year, 37 within 24 hours and 9 within 1 hour of myocardial infarction symptoms. Compared with nonusers, marijuana users were more likely to be men (94% versus 67%, P<0.001), current cigarette smokers (68% versus 32%, P<0.001), and obese (43% versus 32%, P=0.008). They were less likely to have a history of angina (12% versus 25%, P<0.001) or hypertension (30% versus 44%, P=0.002). The risk of myocardial infarction onset was elevated 4.8 times over baseline (95% confidence interval, 2.4 to 9.5) in the 60 minutes after marijuana use. The elevated risk rapidly decreased thereafter. CONCLUSIONS: Smoking marijuana is a rare trigger of acute myocardial infarction. Understanding the mechanism through which marijuana causes infarction may provide insight into the triggering of myocardial infarction by this and other, more common stressors.

Adult↗
PubMed2001

Increased particulate air pollution and the triggering of myocardial infarction.

BACKGROUND: Elevated concentrations of ambient particulate air pollution have been associated with increased hospital admissions for cardiovascular disease. Whether high concentrations of ambient particles can trigger the onset of acute myocardial infarction (MI), however, remains unknown. METHODS AND RESULTS: We interviewed 772 patients with MI in the greater Boston area between January 1995 and May 1996 as part of the Determinants of Myocardial Infarction Onset Study. Hourly concentrations of particle mass <2.5 microm (PM(2.5)), carbon black, and gaseous air pollutants were measured. A case-crossover approach was used to analyze the data for evidence of triggering. The risk of MI onset increased in association with elevated concentrations of fine particles in the previous 2-hour period. In addition, a delayed response associated with 24-hour average exposure 1 day before the onset of symptoms was observed. Multivariate analyses considering both time windows jointly revealed an estimated odds ratio of 1.48 associated with an increase of 25 microg/m(3) PM(2.5) during a 2-hour period before the onset and an odds ratio of 1.69 for an increase of 20 microg/m(3) PM(2.5) in the 24-hour period 1 day before the onset (95% CIs 1.09, 2.02 and 1.13, 2.34, respectively). CONCLUSIONS: The present study suggests that elevated concentrations of fine particles in the air may transiently elevate the risk of MIs within a few hours and 1 day after exposure. Further studies in other locations are needed to clarify the importance of this potentially preventable trigger of MI.

Aged↗
PubMed2001

Sudden cardiac death, genes, and arrhythmogenesis: consideration of new population and mechanistic approaches from a National Heart, Lung, and Blood Institute workshop, Part II.

This is Part II of a 2-part article dealing with malignant ventricular arrhythmias, which are the leading mechanism of death in common cardiac diseases. Genetic population studies directed at discovering common proximal sources of inherited molecular risk most directly linked to arrhythmia initiation and propagation would appear to have considerable potential in helping reduce cardiovascular mortality.

Arrhythmias, Cardiac↗
PubMed2001

Sudden cardiac death, genes, and arrhythmogenesis : consideration of new population and mechanistic approaches from a national heart, lung, and blood institute workshop, part I.

Malignant ventricular arrhythmias are the leading mechanism of death in patients with acute and chronic cardiac pathologies. The extent to which inherited mutations and polymorphic variation in genes determining arrhythmogenic mechanisms affect these patients remains unknown, but based on recent population studies, this risk appears significant, deserving much greater investigation. This report summarizes a National Heart, Lung, and Blood Institute workshop that considered sources of genetic variation that may contribute to sudden cardiac death in common cardiac diseases. Evidence on arrhythmogenic mechanisms in recent population studies suggests a significant portion of the risk of sudden cardiac death in such broad populations may be unrelated to traditional risk factors for predisposing conditions such as atherosclerosis, hypertension, and diabetes and instead may involve unrecognized genetic and environmental interactions that influence arrhythmic susceptibility more directly. Additional population and genetic studies directed at discovering the sources of inherited molecular risk that are most directly linked to arrhythmia initiation and propagation, in addition to studies on previously well-described risk factors, would appear to have considerable potential for reducing premature cardiovascular mortality.

Arrhythmias, Cardiac↗
PubMed2001

Prior alcohol consumption and mortality following acute myocardial infarction.

CONTEXT: Studies have found that individuals who consume 1 alcoholic drink every 1 to 2 days have a lower risk of a first acute myocardial infarction (AMI) than abstainers or heavy drinkers, but the effect of prior drinking on mortality after AMI is uncertain. OBJECTIVE: To determine the effect of prior alcohol consumption on long-term mortality among early survivors of AMI. DESIGN AND SETTING: Prospective inception cohort study conducted at 45 US community and tertiary care hospitals between August 1989 and September 1994, with a median follow-up of 3.8 years. PATIENTS: A total of 1913 adults hospitalized with AMI between 1989 and 1994. MAIN OUTCOME MEASURE: All-cause mortality, compared by self-reported average weekly consumption of beer, wine, and liquor during the year prior to AMI. RESULTS: Of the 1913 patients, 896 (47%) abstained from alcohol, 696 (36%) consumed less than 7 alcoholic drinks/wk, and 321 (17%) consumed 7 or more alcoholic drinks/wk. Compared with abstainers, patients who consumed less than 7 drinks/wk had a lower all-cause mortality rate (3.4 vs 6.3 deaths per 100 person-years; hazard ratio [HR], 0.55; 95% confidence interval [CI], 0.43-0.71) as did those who consumed 7 or more drinks/wk (2.4 vs 6.3 deaths per 100 person-years; HR, 0.38; 95% CI, 0.25-0.55; P<.001 for trend). After adjusting for propensity to drink and other potential confounders, increasing alcohol consumption remained predictive of lower mortality for less than 7 drinks/wk, with an adjusted HR of 0.79 (95% CI, 0.60-1.03), and for 7 or more drinks/wk, with an adjusted HR of 0.68 (95% CI, 0.45-1.05; P =.01 for trend). The association was similar for total and cardiovascular mortality, among both men and women, and among different types of alcoholic beverages. CONCLUSION: Self-reported moderate alcohol consumption in the year prior to AMI is associated with reduced mortality following infarction.

Aged↗
PubMed2001

Height is not associated with long-term survival after acute myocardial infarction.

BACKGROUND: Studies show an inverse association between height and risk of myocardial infarction. How height affects survival after acute myocardial infarction is uncertain. METHODS: In the Determinants of Myocardial Infarction Onset Study, trained interviewers performed chart reviews and face-to-face interviews with 1935 patients hospitalized with acute myocardial infarction in 45 US medical centers between 1989 and 1993. We excluded 15 patients with missing information on height. After a search of the National Death Index for patients who died before 1996, we analyzed the relationship of height and survival with Cox proportional hazards regression. RESULTS: Of the 1920 eligible patients, 317 (17%) died during a median follow-up of 3.8 years. Height was positively associated with younger age, greater educational attainment, and a lower likelihood of being sedentary among both men and women. Height was not associated with long-term survival among women in unadjusted or adjusted analyses. Among men, height was associated with survival only in unadjusted analyses; adjustment for age eliminated this association. We found no relationship between height and survival in any individual age group among men or women. CONCLUSIONS: Although stature may be associated with the risk of acute myocardial infarction, it is not associated with long-term survival after such an event.

Acute Disease↗
PubMed2001

Impact of diabetes on long-term survival after acute myocardial infarction: comparability of risk with prior myocardial infarction.

OBJECTIVE: To determine the effect of diabetes on long-term survival after acute myocardial infarction and to compare its effect with that of a previous myocardial infarction. RESEARCH DESIGN AND METHODS: In a prospective cohort study, we followed 1,935 patients hospitalized with a confirmed acute myocardial infarction at 45 U.S. medical centers between 1989 and 1993, as part of the Determinants of Myocardial Infarction Onset Study. Trained interviewers performed chart reviews and face-to-face interviews with all patients. We analyzed survival using Cox proportional hazards regression to control for potentially confounding factors. RESULTS: Of the 1,935 patients, 320 (17%) died during a mean follow-up of 3.7 years. A total of 399 patients (21%) had previously diagnosed diabetes. Diabetes was associated with markedly higher total mortality in unadjusted (hazard ratio [HR] 2.4; 95% CI 1.9-3.0) and adjusted (1.7; 1.3-2.1) analyses. The magnitude of the effect of diabetes was identical to that of a previous myocardial infarction. The effect of diabetes was not significantly modified by age, smoking, household income, use of thrombolytic therapy, type of hypoglycemic treatment, or duration of diabetes, but the risk associated with diabetes was higher among women than men (adjusted HRs 2.7 vs. 1.3, P = 0.01). CONCLUSIONS: Diabetes is associated with markedly increased mortality after acute myocardial infarction, particularly in women. The increase in risk is of the same magnitude as a previous myocardial infarction and provides further support for aggressive treatment of coronary risk factors among diabetic patients.

Aged↗
PubMed2000

Association of fibrinogen with cardiovascular risk factors and cardiovascular disease in the Framingham Offspring Population.

BACKGROUND: Fibrinogen has been identified as an independent risk factor for cardiovascular disease and associated with traditional cardiovascular risk factors. Also, the role of elevated fibrinogen in thrombosis suggests that it may be on the causal pathway for certain risk factors to exert their effect. These associations remain incompletely characterized. Moreover, the optimal fibrinogen assay for risk stratification is uncertain. METHODS AND RESULTS: In 2632 subjects from cycle 5 of the Framingham Offspring Population, fibrinogen levels were determined with a newly developed immunoprecipitation test (American Biogenetic Sciences) and the functional Clauss method. With the immunoprecipitation method, there were significant linear trends across fibrinogen tertiles (P:<0.001) for age, body mass index, smoking, diabetes mellitus, total cholesterol, HDL cholesterol, and triglycerides in men and women. The Clauss method had significant results (P:<0.030), except for triglycerides in men. Fibrinogen levels were higher for those with compared with those without cardiovascular disease. After covariate adjustment, fibrinogen remained significantly higher in those with cardiovascular disease with the use of the immunoprecipitation test (P:=0.035 and P:=0.018 for men and women, respectively) but not with the Clauss method. CONCLUSIONS: Fibrinogen was associated with traditional cardiovascular risk factors. Elevation of fibrinogen may provide a mechanism for risk factors to exert their effect. Also, fibrinogen levels were higher among subjects with cardiovascular disease compared with those without disease. The immunoprecipitation test showed a stronger association with cardiovascular disease than the Clauss method, suggesting that it may be a useful screening tool to identify individuals at increased thrombotic risk.

Biomarkers↗
PubMed2000

Triggering of cardiac events by sexual activity: findings from a case-crossover analysis.

Although anecdotal reports have suggested that sexual activity increases the risk of acute myocardial infarction (MI), controlled studies to evaluate the magnitude of this risk have only recently been conducted. Using an epidemiologic technique called the case-crossover method, the Myocardial Infarction Onset Study (MIOS) has provided quantitative data on sexual activity as a trigger of MI onset. Sexual activity was found to double the relative risk of acute MI in healthy individuals and patients with a prior history of angina or MI. However, the absolute risk of sexually triggered MI remains extremely low, because the baseline risk of MI is low for most individuals and the increased risk due to sexual activity is transient. Regular exercise also was found to reduce the risk of MI by sexual activity. Given that >12 million people in the United States have coronary artery disease, these findings should be more widely disseminated to reassure patients that, in most cases, sexual activity carries little risk of causing a cardiac event. In the future, advances in research on the triggering of MI are likely to yield new approaches to the prevention of cardiovascular events through prospective identification of the vulnerable plaques that lead to coronary thrombosis, and prophylactic measures to sever the link between triggers and their potentially disastrous consequences.

Female↗
PubMed2000

Management of sexual dysfunction in patients with cardiovascular disease: recommendations of the Princeton Consensus Panel.

Sexual dysfunction is highly prevalent in both sexes and adversely affects patients' quality of life and well being. Given the frequent association between sexual dysfunction and cardiovascular disease, in addition to the potential cardiac risk of sexual activity itself, a consensus panel was convened to develop recommendations for clinical management of sexual dysfunction in patients with cardiovascular disease. Based upon a review of the research and presentations by invited experts, a classification system was developed for stratification of patients into high, low, and intermediate categories of cardiac risk. The large majority of patients are in the low-risk category, which includes patients with (1) controlled hypertension; (2) mild, stable angina; (3) successful coronary revascularization; (4) a history of uncomplicated myocardial infarction (MI); (5) mild valvular disease; and (6) no symptoms and <3 cardiovascular risk factors. These patients can be safely encouraged to initiate or resume sexual activity or to receive treatment for sexual dysfunction. An important exception is the use of sildenafil in patients taking nitrates in any form. Patients in the intermediate-risk category include those with (1) moderate angina; (2) a recent MI (<6 weeks); (3) left ventricular dysfunction and/or class II congestive heart failure; (4) nonsustained low-risk arrhythmias; and (5) >/=3 risk factors for coronary artery disease. These patients should receive further cardiologic evaluation before restratification into the low- or high-risk category. Finally, patients in the high-risk category include those with (1) unstable or refractory angina; (2) uncontrolled hypertension; (3) congestive heart failure (class III or IV); (4) very recent MI (<2 weeks); (5) high-risk arrhythmias; (6) obstructive cardiomyopathies; and (7) moderate-to-severe valvular disease. These patients should be stabilized by specific treatment for their cardiac condition before resuming sexual activity or being treated for sexual dysfunction. A simple algorithm is provided for guiding physicians in the management of sexual dysfunction in patients with varying degrees of cardiac risk.

Adult↗
PubMed2000

Management of sexual dysfunction in patients with cardiovascular disease: recommendations of The Princeton Consensus Panel.

Sexual dysfunction is highly prevalent in both sexes and adversely affects patients' quality of life and well being. Given the frequent association between sexual dysfunction and cardiovascular disease, in addition to the potential cardiac risk of sexual activity itself, a consensus panel was convened to develop recommendations for clinical management of sexual dysfunction in patients with cardiovascular disease. Based upon a review of the research and presentations by invited experts, a classification system was developed for stratification of patients into high, low, and intermediate categories of cardiac risk. The large majority of patients are in the low-risk category, which includes patients with (1) controlled hypertension; (2) mild, stable angina; (3) successful coronary revascularization; (4) a history of uncomplicated myocardial infarction (MI); (5) mild valvular disease; and (6) no symptoms and <3 cardiovascular risk factors. These patients can be safely encouraged to initiate or resume sexual activity or to receive treatment for sexual dysfunction. An important exception is the use of sildenafil in patients taking nitrates in any form. Patients in the intermediate-risk category include those with (1) moderate angina; (2) a recent MI (<6 weeks); (3) left ventricular dysfunction and/or class II congestive heart failure; (4) nonsustained low-risk arrhythmias; and (5) >/=3 risk factors for coronary artery disease. These patients should receive further cardiologic evaluation before restratification into the low- or high-risk category. Finally, patients in the high-risk category include those with (1) unstable or refractory angina; (2) uncontrolled hypertension; (3) congestive heart failure (class III or IV); (4) very recent MI (<2 weeks); (5) high-risk arrhythmias; (6) obstructive cardiomyopathies; and (7) moderate-to-severe valvular disease. These patients should be stabilized by specific treatment for their cardiac condition before resuming sexual activity or being treated for sexual dysfunction. A simple algorithm is provided for guiding physicians in the management of sexual dysfunction in patients with varying degrees of cardiac risk.

Humans↗
PubMed2000

Association of blood pressure with fibrinolytic potential in the Framingham offspring population.

BACKGROUND: Hypertension is an established risk factor for acute coronary events. Because fibrinolytic and hemostatic factors are also associated with cardiovascular disease, we examined the relations of systolic and diastolic blood pressures (SBP and DBP) to levels of plasminogen activator inhibitor antigen, tissue plasminogen activator antigen, fibrinogen, factor VII, von Willebrand factor, fibrinogen, and plasma viscosity in subjects of the Framingham Offspring Study. METHODS AND RESULTS: We studied 1193 men and 1459 women after the exclusion of subjects with known cardiovascular disease and those receiving anticoagulant or antihypertensive therapy. Linear regression models were used to evaluate SBP and DBP as predictors of fibrinolytic and hemostatic factor levels in separate sex models, with adjustment for age, body mass index, smoking, diabetes, total cholesterol, HDL, triglycerides, alcohol intake, and estrogen use (in women). In both sexes, levels of plasminogen activator inhibitor and tissue plasminogen activator antigen were positively related to SBP and DBP (P<0.001). Plasma viscosity was positively related to SBP (P=0.008) and DBP (P=0.001) in women only. There was no association between SBP or DBP and fibrinogen, factor VII, or von Willebrand factor in either sex. CONCLUSIONS: These data suggest that impaired fibrinolysis may play an important role in the pathogenesis of cardiovascular disease in hypertensive patients.

Adult↗
PubMed2000

Increased risk of congestive heart failure among infarctions with nighttime onset.

BACKGROUND: The onset of acute myocardial infarction varies by time of day, with a peak in the morning and a trough at night. Whether infarct-related complications differ by the timing of the infarction is unknown. METHODS AND RESULTS: In the Determinants of Myocardial Infarction Onset Study, we performed chart reviews and face-to-face interviews with 3625 patients with acute myocardial infarction. We assessed the time of onset of symptoms, the presence of ventricular tachycardia or congestive heart failure, and peak creatine kinase levels (in 1043 patients). We found significant circadian variation in the risk of congestive heart failure (P =.001). The risk dropped from 17% for infarctions that began between 6 PM and midnight to 10% for infarctions that began between 6 AM and noon. Adjustment for differences in the time from symptom onset to presentation for care and use of thrombolytic agents did not change the results. We found no circadian variation in the risk of ventricular tachycardia or in peak creatine kinase levels. CONCLUSIONS: The risk of congestive heart failure is highest among infarctions that begin at night. Further research may clarify whether this reflects differences in the pathophysiologic characteristics of infarction or the quality of medical care provided for daytime and nighttime infarctions.

Adult↗