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Biomedical subjects

C D Furberg

Publications and source records attributed to C D Furberg.

At least 73 records · Page 4Linked to original sources
PubMed1998

New evidence on the prevention of cardiovascular events in hypertensive patients with type 2 diabetes.

Recent trials in hypertensive patients with type 2 diabetes reveal important differences in the risk for major cardiovascular events when individual agents are compared. In the Fosinopril Amlodipine Cardiovascular Events Trial (FACET), 380 patients with hypertension and type 2 diabetes were randomized to fosinopril or amlodipine and followed for up to 3.5 years to assess effects on serum lipids. Although both agents effectively controlled blood pressure, amlodipine caused a significantly greater decrease in systolic pressure. At the end of the trial, serum cholesterol, high-density lipoprotein cholesterol, triglycerides, HbA1c, serum glucose, plasma insulin, serum creatinine, and microalbuminuria were similar in both groups. The patients randomized to fosinopril were significantly less likely to experience the prospectively defined combined outcome of acute myocardial infarction (MI), hospitalized angina, or stroke compared to those randomized to amlodipine (RR 0.49; 95% CI 0.26-0.95). In the Appropriate Blood pressure Control in Diabetes (ABCD) trial, 470 patients with hypertension and type 2 diabetes who were randomized to long-acting nisoldipine had an adjusted sevenfold increased risk for acute MI compared to those randomized to enalapril (RR 7.0; 95% CI 2.3-21.4). In the Multicenter Isradipine Diuretic Atherosclerosis Study (MIDAS) trial, the patients with hypertension and above the median of HbA1c (> or =6.7%) randomized to isradipine had a threefold increased risk for major cardiovascular events compared to those randomized to hydrochlorothiazide (RR 2.81; 95% CI 1.09-7.26). These findings are supported by several observational studies. Therefore, evidence is emerging that angiotensin-converting enzyme inhibitors and low-dose diuretics may be more effective than calcium antagonists for prevention of cardiovascular events in hypertensive patients with diabetes or impaired glucose control.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1998

Is the use of some calcium antagonists linked to cancer? Evidence from recent observational studies.

In animal and in vitro studies, several calcium antagonists have been shown to block apoptosis (programmed cell death), a natural cellular defence against cancer. On the basis of these studies, it has been hypothesised that calcium antagonists may function as cancer promoters and that they might cause cancer in humans. The association between the use of calcium antagonists and cancer has been addressed recently in 6 independent epidemiological studies. Four of these studies--2 cohort and 2 case-control--found a significantly higher risk of cancer among users of certain calcium antagonists as compared with either non-users or with users of other antihypertensive agents. The other 2 studies failed to find support for this association. All studies had limitations of varying types and significance. The emerging pattern from these investigations includes the following features: (i) the strength of the association appears to be dependent on daily dosage, ranging from no association in users of low dosages to a 2-fold (or possibly higher) increased risk in users of higher dosages; (ii) the time lag to the appearance of this association appears to be at least 2 to 3 years; (iii) an association with a higher risk of cancer has been found primarily for verapamil, while no such relationship has been reported for diltiazem; and (iv) no highly consistent associations have been shown with specific cancer sites or histological types. More data, preferably from long-term randomised clinical trials, are required before firm conclusions can be drawn.

Age Factors↗
PubMed1998

Isradipine in prediabetic hypertensive subjects.

OBJECTIVE: Investigators from the Multicenter Isradipine Diuretic Atherosclerosis Study (MIDAS) previously reported that the isradipine group had a higher incidence of cardiovascular disease (CVD) events than the diuretic group. The ultimate objective of the analyses presented here was to assess how indices of glycemia (specifically, serum glucose, serum insulin, and HbA1c) might have influenced the effects of the two agents on blood pressure control and CVD events. RESEARCH DESIGN AND METHODS: Inclusion criteria included men and women > or = 40 years of age with ultrasonographically confirmed carotid atherosclerosis and a diastolic blood pressure of > 90 mmHg. Although insulin-dependent diabetic patients were excluded, the three glycemia indices had wide enough ranges to include patients who may be classified as prediabetic. A total of 883 patients were randomized either to the dihydropyridine calcium antagonist (CA) isradipine (2.5-5 mg twice a day) or to the diuretic hydrochlorothiazide (12.5-25 mg twice a day) and followed in double-blind fashion for 3 years. RESULTS: Both treatment groups had achieved comparable control of diastolic blood pressure, and there were no statistically significant differences in any of the glycemia indices, either at baseline or during follow-up. However, the excess isradipine events were noted to be clustered among those patients with elevated baseline levels of HbA1c who also experienced greater blood pressure reductions during follow-up. CONCLUSIONS: The increased cardiovascular risk associated with dihydropyridine CAs in prediabetic patients may be an explanation for the overall CA debate.

Antihypertensive Agents↗
PubMed1997

Use of calcium channel blockers and breast carcinoma risk in postmenopausal women.

BACKGROUND: The use of calcium channel blockers in an elderly population recently was reported to be associated with the incidence of cancer. The Cardiovascular Health Study, a multisite observational cohort study, provided the opportunity to investigate the epidemiologic association between the use of calcium channel blockers and breast carcinoma risk in 3198 women age > or = 65 years. METHODS: Standard questionnaires and clinical procedures were administered at four study sites annually from 1989-1990 to 1993-1994. Drug usage was assessed by a medication inventory and hospitalizations for 75 incident invasive breast carcinoma cases were identified using International Classification of Diseases-9 Clinical Modification codes. Time-dependent Cox proportional hazards regression models were used to assess associations between incident breast carcinoma and the use of specific antihypertensive medication including calcium channel blockers. RESULTS: In adjusted Cox proportional hazards models, an elevated risk of breast carcinoma was associated with use of calcium channel blockers (hazard ratio [HR]: 2.57; 95% confidence interval [CI], 1.47-4.49). This association persisted when the comparison group was users of other antihypertensive medication. No associations between the use of other antihypertensive medication with incident breast carcinoma were found. Associations were enhanced by assessment of high dose at baseline (HR: 4.42; 95% CI, 1.37-14.27) and when calcium channel blockers were combined with estrogen use (HR: 4.48; 95% CI, 1.58-12.75). The association was found to be strongest for the use of estrogens with immediate release calcium channel blockers (HR: 8.48; 95% CI, 2.99-24.08). CONCLUSIONS: Although the number of cases was limited in this observational study, associations found between the use of calcium channel blockers and incident invasive breast carcinoma warrant further investigation. Site specific carcinomas should be included as an outcome of ongoing and planned long term clinical trials using calcium channel blockers.

Age Factors↗
PubMed1997

Rationale, design, and baseline characteristics of the Prospective Randomized Evaluation of the Vascular Effects of Norvasc Trial (PREVENT).

The Prospective Randomized Evaluation of the Vascular Effects of Norvasc Trial is the first angiographic clinical trial to be designed to test whether an agent can slow or even reverse the progression of early coronary atherosclerosis in patients with documented disease. In addition, a subset of patients are undergoing carotid ultrasound examinations, providing a unique opportunity to assess and correlate disease progression in 2 arterial beds.

Aged↗
PubMed1997

Incidence of and risk factors for atrial fibrillation in older adults.

BACKGROUND: This study aimed to describe the incidence of atrial fibrillation (AF) among older adults during 3 years of follow-up. METHODS AND RESULTS: In this cohort study, 5201 adults > or = 65 years old were examined annually on four occasions between June 1989 and May 1993. At baseline, participants answered questionnaires and underwent a detailed examination that included carotid ultrasound, pulmonary function tests, ECG, and echocardiography. Subjects with a pacemaker or AF at baseline (n=357) were excluded. New cases of AF were identified from three sources: (1) annual self-reports, (2) annual ECGs, and (3) hospital discharge diagnoses. Cox proportional-hazards models were used to assess baseline risk factors as predictors of incident AF. Among 4844 participants, 304 developed a first episode of AF during an average follow-up of 3.28 years, for an incidence of 19.2 per 1000 person-years. The onset was strongly associated with age, male sex, and the presence of clinical cardiovascular disease. For men 65 to 74 and 75 to 84 years old, the incidences were 17.6 and 42.7, respectively, and for women, 10.1 and 21.6 events per 1000 person-years. In stepwise models, the use of diuretics, a history of valvular heart disease, coronary disease, advancing age, higher levels of systolic blood pressure, height, glucose, and left atrial size were all associated with an increased risk of AF. The use of beta-blockers and high levels of alcohol use, cholesterol, and forced expiratory volume in 1 second were associated with a reduced risk of AF. CONCLUSIONS: The incidence of AF in older adults may be higher than estimated by previous population studies. Left atrial size appears to be an important risk factor, and the control of blood pressure and glucose may be important in preventing the development of AF.

Adult↗
PubMed1997

Reductase inhibitor monotherapy and stroke prevention.

BACKGROUND: Epidemiologic evidence and meta-analyses of data from early clinical trials suggest that lowering the levels of cholesterol does not reduce the events of stroke. These analyses have not included more recent clinical trials using reductase inhibitors. OBJECTIVE: To conduct a meta-analysis of the effect of reducing cholesterol levels on stroke in all reported clinical trials of primary (n = 4) and secondary (n = 8) prevention of coronary heart disease that used reductase inhibitor monotherapy and provided information on incident stroke. RESULTS: Analysis of combined data from primary and secondary prevention trials showed a highly statistically significant reduction of stroke associated with the use of reductase inhibitor monotherapy (27% reduction in stroke; P = .001). Analysis of secondary prevention trials alone disclosed a similar statistically significant effect (32% reduction in stroke; P = .001). A smaller nonsignificant reduction in stroke was noted in the primary prevention trials (15% reduction in stroke; P = .48). CONCLUSIONS: Reductase inhibitors now in use for lowering cholesterol levels are more potent and have fewer side effects than the cholesterol-lowering agents previously available. They appear to reduce stroke, most notably in patients with prevalent coronary artery disease, which may be partly due to the effects of lowering the levels of cholesterol on the progression and plaque stability of extracranial carotid atherosclerosis or the marked reduction of incident coronary heart disease associated with treatment.

Adult↗
PubMed1997

Health outcomes associated with antihypertensive therapies used as first-line agents. A systematic review and meta-analysis.

OBJECTIVE: To review the scientific evidence concerning the safety and efficacy of various antihypertensive therapies used as first-line agents and evaluated in terms of major disease end points. DATA SOURCES: MEDLINE searches and previous meta-analyses for 1980 to 1995. DATA SELECTION: We selected long-term studies that assessed major disease end points as an outcome. For the meta-analysis, we chose placebo-controlled randomized trials. For randomized trials using surrogate end points such as blood pressure, we selected the largest studies that evaluated multiple drugs. Where clinical trial evidence was lacking, we relied on information from observational studies. DATA SYNTHESIS: Diuretics and beta-blockers have been evaluated in 18 long-term randomized trials. Compared with placebo, beta-blocker therapy was effective in preventing stroke (relative risk [RR], 0.71; 95% confidence interval [CI], 0.59-0.86) and congestive heart failure (RR, 0.58; 95% CI, 0.40-0.84). The findings were similar for high-dose diuretic therapy (for stroke, RR, 0.49; 95% CI, 0.39-0.62; and for congestive heart failure, RR, 0.17; 95% CI, 0.07-0.41). Low-dose diuretic therapy prevented not only stroke (RR, 0.66; 95% CI, 0.55-0.78) and congestive heart failure (RR, 0.58; 95% CI, 0.44-0.76) but also coronary disease (RR, 0.72; 95% CI, 0.61-0.85) and total mortality (RR, 0.90; 95% CI, 0.81-0.99). Although calcium channel blockers and angiotensin-converting enzyme (ACE) inhibitors reduce blood pressure in hypertensive patients, the clinical trial evidence in terms of health outcomes is meager. For several short-acting dihydropyridine calcium channel blockers, the available evidence suggests the possibility of harm. Whether the long-acting formulations and the nondihydropyridine calcium channel blockers are safe and prevent major cardiovascular events in patients with hypertension remains untested and therefore unknown. CONCLUSION: Until the results of large long-term clinical trials evaluating the effects of calcium channel blockers and ACE inhibitors on cardiovascular disease incidence are completed, the available scientific evidence provides strong support for the current national guidelines, which recommend diuretics and beta-blockers as firstline agents and low-dose therapy for all antihypertensive agents.

Adrenergic beta-Antagonists↗
PubMed1997

Clinical implications of the World Health Organization-International Society of Hypertension statement on calcium antagonists.

The controversy over the efficacy and safety of calcium antagonists is over 2 years old. Since millions of patients worldwide are currently using calcium antagonists for the treatment of high blood pressure and angina, a systematic review of their potential risks and benefits is much needed. In response to this need, the World Health Organization (WHO) and the International Society of Hypertension (ISH) recently convened an ad-hoc subcommittee to review the available evidence (J Hypertens 1997, 15:105-115). Importantly, the WHO-ISH statement does take a strong stand in favor of large long-term trials that compare antihypertensive agents, and we all agree that these comparative trials are urgently needed. However, the WHO-ISH statement is marred in part by errors of omission, by the selective use of evidence and epidemiologic principles, and by a narrow application of the viewpoint of those who believe that evidence can come only from the results of megatrials. As a result, practicing clinicians will find more useful information in existing hypertension and postmyocardial infarction guidelines (Arch Intern Med 1993, 153:154-183 and JAm Coll Cardiol 1996, 28:1328-1428).

Calcium Channel Blockers↗
PubMed1997

The association of antihypertensive agents with MRI white matter findings and with Modified Mini-Mental State Examination in older adults.

OBJECTIVES: To examine the association of antihypertensive regimen with magnetic resonance imaging (MRI) white matter hyperintensity and with cognitive impairment in older adults. DESIGN: Cross-sectional study. SETTING: The Cardiovascular Health study, an observational prospective cohort study of risk factors for coronary heart disease and stroke in men and women 65 years of age and older. PARTICIPANTS: 1268 men and women with pharmacologically treated hypertension. MEASUREMENTS: Information on medication use, medical history, and health habits was collected at clinic examinations. Participants completed the Modified Mini-Mental State Examination (3MS) and underwent MRI examination. Without clinical information, study neuroradiologists assigned an overall grade of white matter signal intensity on MRI on a scale from 0 (no findings) to 9 (extensive findings). RESULTS: Adjusted mean white matter grade was higher for users of calcium channel blockers (2.59, P = .007) and users of loop diuretics (2.60, P = .015) than for users of beta blockers (2.12). The association was present for both dihydropyridine and non-dihydropyridine calcium channel blockers. Adjusted mean 3MS scores were lower for users of calcium channel blockers (89.6, P < .002), especially dihydropyridines, and users of loop diuretics (89.7, P < .006) than for users of beta blockers (92.3). No statistically significant association could be shown for users of other drug regimens, including thiazides and ACE inhibitors. CONCLUSION: In this study, users of antihypertensive regimens which included calcium channel blockers or loop diuretics had more severe white matter hyperintensity on MRI and worse performance on 3MS than users of beta blockers.

Adrenergic beta-Antagonists↗
PubMed1997

Pulmonary function testing in population-based studies.

A wealth of information on pulmonary function is currently available in NHLBI-sponsored, population-based studies. These data can be used to address critically important questions in pulmonary and cardiovascular disease research, but their potential cannot be realized without the active collaboration of pulmonary- and cardiovascular-disease researchers. Investigators interested in analyzing these data in collaboration with the parent study investigators are invited to contact these investigators directly (see APPENDIX). Results of analyses recommended in the workshop should be used to identify hypotheses for future efforts in collecting data on the epidemiology of pulmonary diseases and their relationship to cardiovascular disease.

Adolescent↗
PubMed1996

Cost-effectiveness of pravastatin in secondary prevention of coronary artery disease.

This study analyzed the cost-effectiveness of pravastatin in secondary prevention of coronary artery disease (CAD). The projected risk model in 445 male patients with established CAD and moderately elevated serum low-density lipoprotein cholesterol used results data from 2 placebo-controlled plaque regression trials: Pravastatin Limitation of Atherosclerosis in the Coronary Arteries and Pravastatin, Lipids, and Atherosclerosis in the Carotids. Framingham Heart Study data were used to project the risk of mortality 10 years after myocardial infarction (MI) for incremental male patients in the placebo group who had MI. A Markov process was used to estimate life-years saved, and decision analysis was used to estimate cost. Depending on the patient-risk profile, the midrange estimated cost per life-year saved with pravastatin in secondary prevention of CAD varied from $7,124 to $12,665, which is favorable compared with other widely accepted medical interventions.

Anticholesteremic Agents↗