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Biomedical subjects

C D Furberg

Publications and source records attributed to C D Furberg.

At least 109 records · Page 6Linked to original sources

Results of the primary outcome measure and clinical events from the Asymptomatic Carotid Artery Progression Study.

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors have proven to be more effective in reducing levels of low density lipoprotein (LDL) cholesterol and to be better tolerated than other lipid-lowering compounds. Most of the trials evaluating the effects of these new agents on progression of atherosclerosis have not included individuals asymptomatic for cardiovascular disease and who have LDL cholesterol levels at or below the limits established by the National Cholesterol Education Program for initiating treatment. The Asymptomatic Carotid Artery Progression Study (ACAPS) tested the effect of the HMG-CoA reductase inhibitor, lovastatin, on early-stage carotid atherosclerosis (as detected by B-mode ultrasonography) in 919 asymptomatic men and women, 40-79 years of age, who had LDL cholesterol levels between the 60th and 90th percentiles. Participants randomized into this double-blind, placebo-controlled, factorially designed study received lovastatin (20-40 mg/day) or lovastatin-placebo and warfarin (1 mg/day), or warfarin-placebo over a 3-year period. The progression of the mean maximum intimal-medial thickness (IMT) over 12 walls of both carotid arteries represented the primary outcome. Lovastatin treatment was associated with a reduction in progression of mean maximum IMT (p < 0.001). Levels of LDL cholesterol were reduced by 28% (43.5 mg/dl [11.25 mmol/liter]) in the lovastatin group within 6 months (p < 0.0001) and remained stable throughout the follow-up period, whereas these levels remained essentially unchanged in the lovastatin-placebo group. The difference in incidence of major cardiovascular events for patients in the lovastatin-placebo group was significant: 5 versus 14, respectively (p < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Pravastatin, Lipids, and Atherosclerosis in the Carotid Arteries (PLAC-II).

The Pravastatin, Lipids, and Atherosclerosis in the Carotid Arteries trial (PLAC-II) was initiated in 1987 and was the first double-blind, randomized clinical trial with progression of early extracranial carotid atherosclerosis as an outcome variable. We randomized 151 coronary patients to placebo or pravastatin and treated them for 3 years. B-mode ultrasound quantification of carotid artery intimal-medial thickness (IMT) was obtained at baseline and sequentially during this period. The primary outcome was the change in the mean of the maximum IMT measurements over time. Effects on individual carotid artery segments (common, bifurcation, internal carotid artery) and on clinical events were also investigated. During follow-up, plasma concentrations of total cholesterol were lower in pravastatin-treated patients compared with those of placebo-treated patients (4.81 vs 6.08 mmol/liter [186 vs 235 mg/dl]) as were concentrations of low density lipoprotein (LDL) cholesterol (3.10 vs 4.29 mmol/liter [120 vs 167 mg/dl]). Plasma concentrations of high density lipoprotein2 (HDL2) cholesterol were higher in pravastatin-treated patients than in placebo-treated patients (0.16 vs 0.14 mmol/liter [6.1 vs 5.5 mg/dl]). Active treatment resulted in a nonsignificant 12% reduction in progression of the mean-maximum IMT (from 0.068 mm/yr placebo to 0.059 mm/yr pravastatin) and a statistically significant 35% reduction in IMT progression in the common carotid (p = 0.03). Active treatment was also associated with a 60% reduction of nonfatal myocardial infarction plus death caused by coronary artery disease (p = 0.09), a 61% reduction of any fatal event plus any nonfatal myocardial infarction (p = 0.04), and an 80% reduction of fatal plus any nonfatal myocardial infarction (p = 0.03).

Anticholesteremic Agents↗

Reduction in coronary events during treatment with pravastatin. PLAC I and PLAC II Investigators. Pravastatin Limitation of Atherosclerosis in the Coronary Arteries.

The 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors, or statins, are more efficacious than older lipid-lowering agents and therefore may be more effective in reducing the incidence of coronary events. The objective of this prespecified analysis was to examine in coronary patients the effect of the lipid-lowering agent pravastatin on 3-year rates of coronary event incidence, all-cause mortality, and nonfatal myocardial infarction (MI), and to determine whether any observed benefit was also evident in patients > or = 65 years of age. The design of this analysis was to pool the data from 2 concurrent 3-year placebo-controlled clinical trials of pravastatin monotherapy in coronary patients (Pravastatin Limitation of Atherosclerosis in the Coronary Arteries [PLAC I] and the Pravastatin, Lipids, and Atherosclerosis in the Carotid Arteries [PLAC II]). This pooled database included 559 coronary patients with moderately elevated levels of low density lipoprotein cholesterol (between the 60th and 90th percentiles for age and gender in the United States). Over the 3 years of follow-up, use of pravastatin was associated with a 55% reduction in coronary incidence (p = 0.014). Pravastatin was also associated with a 67% reduction in nonfatal MI (p = 0.006). Eleven placebo patients died over the 3 years of follow-up compared with 7 in the pravastatin groups (a 40% reduction). Among older patients (age > or = 65 years), pravastatin therapy was associated with a 79% reduction in coronary event incidence (95% confidence interval [CI] 33-100%) and with a 86% reduction in nonfatal myocardial infarction (CI, 35-100%).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Nifedipine. Dose-related increase in mortality in patients with coronary heart disease.

BACKGROUND: The purpose of this study was to assess the effect of the dose of nifedipine, a dihydropyridine calcium antagonist, on the increased risk of mortality seen in the randomized secondary-prevention trials and to review the mechanisms by which this adverse effect might occur. METHODS AND RESULTS: We restricted the dose-response meta-analysis to the 16 randomized secondary-prevention trials of nifedipine for which mortality data were available. Recent trials of any calcium antagonist and formulation were also reviewed for information about the possible mechanisms of action that might increase mortality. Overall, the use of nifedipine was associated with a significant adverse effect on total mortality (risk ratio, 1.16, with a 95% CI of 1.01 to 1.33). This summary estimate fails to draw attention to an important dose-response relationship. For daily doses of 30 to 50, 60, and 80 mg, the risk ratios for total mortality were 1.06 (95% CI, 0.89 to 1.27), 1.18 (95% CI, 0.93 to 1.50), and 2.83 (95% CI, 1.35 to 5.93), respectively. In a formal test of dose response, the high doses of nifedipine were significantly associated with increased mortality (P = .01). While the mechanism of this adverse effect is not known, there are several plausible explanations, including the established proischemic effect, negative inotropic effects, marked hypotension, recently reported prohemorrhagic effects attributed to antiplatelet and vasodilatory actions of calcium antagonists, and possibly proarrhythmic effects. CONCLUSIONS: In patients with coronary disease, the use of short-acting nifedipine in moderate to high doses causes an increase in total mortality. Other calcium antagonists may have similar adverse effects, in particular those of the dihydropyridine type. Long-term safety data are lacking for most calcium antagonists.

Angina Pectoris↗

Trends in pharmacologic management of hypertension in the United States.

BACKGROUND: Two new classes of antihypertensive agents were introduced in the 1980s, but their effectiveness in preventing heart disease and stroke has not been demonstrated. Lack of evidence of their efficacy might reasonably be expected to discourage their widespread use in management of hypertension. METHODS: Use of various classes of antihypertensive agents was estimated from published drug use information in an effort to estimate trends in antihypertensive drug use and evaluate the impact of these trends on costs of antihypertensive therapy in the United States. RESULTS: Proportionate use of the five major antihypertensive drug classes shifted markedly between 1982 and 1993. Diuretics accounted for 56% of all hypertensive drug mentions in 1982 but only 27% in 1993, a relative decline of 52%. Use of beta-blockers and central agents also declined during this period. Proportionate use of calcium antagonists showed the greatest gains, increasing from 0.3% to 27%, while the use of angiotensin-converting enzyme inhibitors increased from 0.8% to 24%. Given the higher costs of the newer agents, and assuming an estimated total cost of antihypertensive medications in 1992 of $7 billion, approximately $3.1 billion would have been saved had 1982 prescribing practices remained in effect in 1992. CONCLUSIONS: Use of calcium antagonists and angiotensin-converting enzyme inhibitors in hypertension has increased dramatically in the past 10 years. Without convincing evidence of the advantages of these agents, it is difficult to explain the continued decline in the use of less expensive agents, such as diuretics and beta-blockers, which are the only antihypertensive agents proved to reduce stroke and coronary disease in hypertensive patients.

Adult↗

Cholesterol reduction yields clinical benefit. A new look at old data.

BACKGROUND: There has been a continuing debate about the overall benefit of cholesterol lowering. We performed a novel meta-analysis of all randomized trials of more than 2 years' duration (n = 35 trials) to describe how coronary-heart-disease (CHD), non-CHD, and total mortality are related to cholesterol lowering and to type of intervention. METHODS AND RESULTS: The analytic approach was designed to separate the effects of cholesterol lowering itself from the other effects of the different types of intervention used. For every 10 percentage points of cholesterol lowering, CHD mortality was reduced by 13% (P < .002) and total mortality by 10% (P < .03). Cholesterol lowering had no effect on non-CHD mortality. Certain types of intervention had specific effects independent of cholesterol lowering. Fibrates (clofibrates, 7 trials; gemfibrozil, 2 trials) increased non-CHD mortality by about 30% (P < .01) and total mortality by about 17% (P < .02). Hormones (estrogen, 2 trials; dextrothyroxin, 2 trials) increased CHD mortality in men by about 27% (P < .04), non-CHD mortality by about 55% (P < .03), and total mortality by about 33% (P < .01). No specific effects independent of cholesterol lowering were found due to diet (n = 11) or other interventions (resins, 5; niacin, 3; statins, 2; partial ileal bypass, 1). CONCLUSIONS: The results suggest that cholesterol lowering itself is beneficial but that specific adverse effects of fibrates and hormones increase the risk of CHD (hormones only), non-CHD, and total mortality.

Cholesterol↗

Pravastatin, Lipids, and Atherosclerosis in the Carotid Arteries (PLAC-II)

We randomized 151 coronary patients to placebo or pravastatin and treated them for 3 years. B-mode ultrasound quantification of carotid artery intimal-medial thickness (IMT) was obtained at baseline and sequentially during this period. The primary outcome was the change in the mean of the maximal IMT measurements across time. Effects on individual carotid artery segments (common, bifurcation, and internal carotid) and on clinical events were also investigated. Plasma concentrations of total cholesterol were lower with active treatment than with placebo (4.80 vs 6.07 mmol/L [186 vs 235 mg/dl], respectively) as were concentrations of low-density lipoprotein cholesterol (3.11 vs 4.30 mmol/L [120 vs 167 mg/dl], respectively). Plasma concentrations of high-density lipoprotein2 cholesterol were higher with active treatment (0.16 vs 0.14 mmol/L [6.1 vs 5.5 mg/dl], respectively). Active treatment resulted in a nonsignificant 12% reduction in progression of the mean-maximum IMT (from 0.068 to 0.059 mm/year) and a statistically significant 35% reduction in IMT progression in the common carotid. Active treatment was also associated with a reduction in fatal and nonfatal coronary events [corrected] (p = 0.09) and of any fatal event plus nonfatal myocardial infarction (p = 0.04).

Arteriosclerosis↗

Does antihypertensive treatment of the elderly prevent cardiovascular events or prolong life? A meta-analysis of hypertension treatment trials.

OBJECTIVE: To estimate the short-term effects of drug treatment of hypertension in the elderly (> or = 60 years of age) on stroke, major coronary events, and mortality rates. DESIGN: Meta-analysis of all published randomized, controlled trials that addressed the impact of drug treatment of hypertension in the elderly on the above outcomes. SETTING AND PATIENTS: All published clinical trials that met the above criteria involved men and women recruited from primary care practices or through community screenings, who were then treated according to protocol at either community or specialty clinics. Eight randomized, controlled trials that included 15,990 patients treated for an average of 4.6 years were included in this meta-analysis. INTERVENTIONS: Patients received either active antihypertensive treatment or placebo in seven of the studies and programmed stepped care vs referral back to the usual care source in one study. MAIN OUTCOME MEASURES: Fatal or nonfatal myocardial infarction or sudden coronary death; fatal or nonfatal stroke; and all-cause mortality. Outcomes were analyzed on an intention-to-treat basis. RESULTS: Mean baseline blood pressure was 179/90 mm Hg, with a mean treatment effect of 15/6 mm Hg. Homogeneity tests indicated validity of the combined results. Pooled relative risks, calculated as treatment or control (with 95% confidence intervals) for the main end points, were as follows: fatal or nonfatal major coronary event, 0.82 (0.73 to 0.92); fatal or nonfatal stroke, 0.65 (0.57 to 0.75); and death from any cause, 0.85 (0.78 to 0.92) (P < .005 for each). CONCLUSION: Antihypertensive treatment in the elderly prevents major coronary events and stroke and prolongs life, with significant treatment effects observed within only 5 years.

Aged↗

Ischemic episodes in 24-h ambulatory electrocardiograms of elderly persons: the Cardiovascular Health Study.

We examined correlates of ischemic episodes in 24-h ambulatory electrocardiograms (ECG) in a sample of 1511 men and women 65 years old and older. Ischemic episodes had a high prevalence period during early afternoon and also during morning hours after awakening, and the overall prevalence was 13% in men and 9% in women (P < 0.001 for gender difference). The prevalence was 9.6% in participants with no history of myocardial infarction and no major or minor resting ECG abnormalities. In multivariate analysis by logistic regression, being on digitalis medication was associated with over a three-fold risk of ischemic episodes, with an odds ratio (95% confidence limits) of 3.21 (1.80 to 5.74). Left ventricular hypertrophy by ECG and atrial fibrillation had almost a three-fold excess risk of ischemic episodes, with odds ratios 2.81 (1.37 to 5.74) and 2.63 (1.17 to 5.91), respectively. Isolated ST-T abnormalities had almost a two-fold excess of ischemic episodes, with an odds ratio of 1.89 (1.01 to 3.54). Being overweight was associated with a 33% reduced likelihood of ischemic episodes after adjustment for other factors, with an odds ratio of 0.67 (0.46 to 0.98). It is concluded that the prevalence of silent ischemic episodes is high in older men and women.

Age Factors↗

Lessons learned from a prospective meta-analysis.

OBJECTIVE: To describe the unique aspects of and the lessons learned in planning and conducting a pooled analysis of multiple trials evaluating interventions to reduce functional decline in hospitalized older persons. Specific examples from the Hospital Outcomes Project for the Elderly (HOPE) meta-analysis are discussed. DESIGN: A prospective meta-analysis (PMA) that compiled and pooled data from concurrently conducted clinical trials testing related but distinct interventions. SETTING: The Data Coordinating Center for the prospective meta-analysis coordinated the collection and analysis of common outcome data from five university-affiliated hospitals and one community hospital conducting the clinical trials. PARTICIPANTS: Acutely ill hospitalized elderly participants at least 65 to 75 years old. INTERVENTIONS: Treatments being evaluated included exercise, physical therapy, a multidisciplinary geriatric care unit, a multidisciplinary in-hospital intervention with post-discharge care, a nursing-based geriatric care program, and a program to improve detection and evaluation of delirious patients. CONCLUSION: The prospective meta-analysis provides selected advantages over independently conducted clinical trials and retrospective meta-analyses. It does, however, pose special design and operational challenges that must be addressed well before initiation of the individual trials. Specific issues of concern include: maintaining scientific integrity of both the individual trials and the PMA; reaching consensus on PMA goals, what data to collect, how and when to collect them and how to maintain uniformly high quality data across all sites; defining the role of the Data Coordinating Center in a multicenter project that utilizes different trials and protocols; and establishing policies concerning analyses of the pooled data, publication of pooled analyses, and ownership of the pooled database.

Aged↗

Should calcium antagonists be first line drugs in hypertension?

The goal of the treatment of hypertension is to reduce the risk of the cardiovascular complications--stroke, acute myocardial infarction, congestive heart failure and renal dysfunction--not just to lower an elevated blood pressure. There are no completed large long-term clinical trials of calcium antagonists--short-acting or long-acting--designed to assess their efficacy and safety in patients with hypertension. Two smaller trials of dihydropyridines have suggested that despite blood pressure control, there may be a paradoxical increase in cardiovascular complications. These adverse effects are similar to those reported from clinical trials of short-acting calcium antagonists in coronary patients. Due to concerns about their long-term safety, inadequate documentation of their long-term efficacy and their high cost, calcium antagonists should be reserved as third-line agents. If prescribed, they should be given in low doses, possibly in combination with another antihypertensive agent. Their use should be limited to patients who cannot tolerate the other proven agents such as diuretics and beta-blockers, and to those who are not controlled on these agents or those with relative or absolute contraindication to them.

Antihypertensive Agents↗

Prevalence of atrial fibrillation in elderly subjects (the Cardiovascular Health Study).

Atrial fibrillation (AF) is a common arrhythmia in elderly persons and a common cause of embolic stroke. Most studies of the prevalence and correlates of AF have used selected, hospital-based populations. The Cardiovascular Health Study is a population-based, longitudinal study of risk factors for coronary artery disease and stroke in 5,201 men and women aged > or = 65 years. AF was diagnosed in 4.8% of women and in 6.2% of men at the baseline examination, and prevalence was strongly associated with advanced age in women. Prevalence of AF was 9.1% in men and women with clinical cardiovascular disease, 4.6% in patients with evidence of subclinical but no clinical cardiovascular disease, and only 1.6% in subjects with neither clinical nor subclinical cardiovascular disease. A history of congestive heart failure, valvular heart disease and stroke, echocardiographic evidence of enlarged left atrial dimension, abnormal mitral or aortic valve function, treated systemic hypertension, and advanced age were independently associated with the prevalence of AF. The low prevalence of AF in the absence of clinical and subclinical cardiovascular disease calls into question the existence and clinical usefulness of the concept of so-called "lone atrial fibrillation" in the elderly.

Aged↗