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Biomedical subjects

William R Hiatt

Publications and source records attributed to William R Hiatt.

18 recordsLinked to original sources
PubMed2003

Cholesterol reduction with atorvastatin improves walking distance in patients with peripheral arterial disease.

BACKGROUND: Cholesterol modification reduces cardiovascular events in patients with atherosclerosis, including those with peripheral arterial disease. The purpose of this study was to determine whether cholesterol lowering with atorvastatin improves walking performance in patients with intermittent claudication. METHODS AND RESULTS: This randomized, double-blind, parallel-design study included 354 persons with claudication attributable to peripheral arterial disease. Patients were treated with placebo, atorvastatin (10 mg per day), or atorvastatin (80 mg per day) for 12 months. The outcome measures included change in treadmill exercise time and patient-reported measures of physical activity and quality of life based on questionnaires. Maximal walking time after 12 months of treatment with atorvastatin did not change significantly. However, there was improvement in pain-free walking time after 12 months of treatment for the 80-mg (P=0.025) group compared with placebo. A physical activity questionnaire demonstrated improvement in ambulatory ability for the 10- and 80-mg groups (P=0.011), whereas 2 quality of life instruments, the Walking Impairment Questionnaire and Short Form 36 Questionnaire, did not show significant change. CONCLUSIONS: Atorvastatin improves pain-free walking distance and community-based physical activity in patients with intermittent claudication. When treated with atorvastatin, patients with peripheral arterial disease may experience improvement in symptoms to complement the anticipated reduction in cardiovascular events reported in other studies of statins.

Aged↗
PubMed2003

Treatment of intermittent claudication with beraprost sodium, an orally active prostaglandin I2 analogue: a double-blinded, randomized, controlled trial.

OBJECTIVES: In the current study, we hypothesized that beraprost would: 1) improve treadmill exercise performance and quality of life; and 2) decrease rates of ischemic events in patients with intermittent claudication. BACKGROUND: Previous trials with beraprost sodium, an orally active prostaglandin I(2) analogue, in the treatment of claudication in patients with peripheral arterial disease (PAD) have been inconsistent. METHODS: Patients with intermittent claudication (n = 897) were randomized to receive either 40 microg three times a day of beraprost with meals (n = 385) or placebo (n = 377) in a double-blinded manner for one year. The primary efficacy parameter was treadmill-measured maximum walking distance, as assessed at three and six months after randomization. Secondary efficacy parameters included treadmill-measured pain-free walking distance and change in quality of life. RESULTS: There was no significant improvement in maximum walking distance in the beraprost group (16.7%) as compared with the placebo group (14.6%, p = NS). Administration of beraprost did not improve the pain-free walking distance (p = NS between treatment groups), and there was no improvement in the quality-of-life measures between the treatment groups. The incidence of critical cardiovascular events was 7.3% in the beraprost group and 11.4% in the placebo group (p = NS). There was a significant reduction in the combination of cardiovascular death and myocardial infarction in the beraprost group (p = 0.01). CONCLUSIONS: Despite previous investigations suggesting efficacy, these results indicate that beraprost is not an effective treatment to improve symptoms of intermittent claudication in patients with PAD. The potential benefit of beraprost on critical cardiovascular events would require confirmation in a larger prospective investigation.

Administration, Oral↗
PubMed2003

Lack of improvement in the treatment of hyperlipidemia among patients with type 2 diabetes.

PURPOSE: We investigated the adequacy of treatment of hyperlipidemia in patients with type 2 diabetes, and assessed the temporal trends in adherence to published guidelines. METHODS: We performed a post hoc analysis of 501 patients enrolled in the Appropriate Blood Pressure Control in Diabetes trial. All patients had fasting lipid profiles at baseline and during the 5 years (1993 to 1998) of the trial. Achieving the National Cholesterol Education Panel's goals for hyperlipidemia management was the primary outcome. RESULTS: The percentage of patients with a low-density lipoprotein (LDL) cholesterol level less than 130 mg/dL was 53% (n = 266) at baseline and 54% (n = 270) at the end of 5 years (P = 0.75). Almost 14% (n = 69) of these patients continued to have an LDL cholesterol level greater than 160 mg/dL at the completion of the study. Only 19% (n = 25) of the 133 patients with known coronary artery disease had an LDL cholesterol level less than 100 mg/dL at baseline, and only 16% (n = 21) achieved this level at the completion of the study (P = 0.37). CONCLUSION: Although prevention of cardiovascular disease in patients with diabetes is a public health priority, our results suggest that hyperlipidemia is being treated suboptimally.

Cholesterol, LDL↗
PubMed2003

Intensive blood pressure control reduces the risk of cardiovascular events in patients with peripheral arterial disease and type 2 diabetes.

BACKGROUND: Peripheral arterial disease (PAD) and diabetes are both associated with a high risk of ischemic events, but the role of intensive blood pressure control in PAD has not been established. METHODS AND RESULTS: The Appropriate Blood Pressure Control in Diabetes study followed 950 subjects with type 2 diabetes for 5 years; 480 of the subjects were normotensive (baseline diastolic blood pressure of 80 to 89 mm Hg). Patients randomized to placebo (moderate blood pressure control) had a mean blood pressure of 137+/-0.7/81+/-0.3 mm Hg over the last 4 years of treatment. In contrast, patients randomized to intensive treatment with enalapril or nisoldipine had a mean 4-year blood pressure of 128+/-0.8/75+/-0.3 mm Hg (P<0.0001 compared with moderate control). PAD, which is defined as an ankle-brachial index <0.90 at the baseline visit, was diagnosed in 53 patients. In patients with PAD, there were 3 cardiovascular events (13.6%) on intensive treatment compared with 12 events (38.7%) on moderate treatment (P=0.046). After adjustment for multiple cardiovascular risk factors, an inverse relationship between ankle-brachial index and cardiovascular events was observed with moderate treatment (P=0.009), but not with intensive treatment (P=0.91). Thus, with intensive blood pressure control, the risk of an event was not increased, even at the lowest ankle-brachial index values, and was the same as in a patient without PAD. CONCLUSIONS: In PAD patients with diabetes, intensive blood pressure lowering to a mean of 128/75 mm Hg resulted in a marked reduction in cardiovascular events.

Antihypertensive Agents↗
PubMed2003

Functional outcome in a contemporary series of major lower extremity amputations.

PURPOSE: We undertook this study to document the functional natural history of patients undergoing major amputation in an academic vascular surgery and rehabilitation medicine practice. METHODS: A retrospective review was conducted of consecutive patients undergoing major lower extremity amputation and rehabilitation in a university and Department of Veterans Affairs hospital. Main outcome variables included operative mortality, follow-up, survival, median time to incision healing, secondary operative procedures for wound management, and conversion from below-knee amputation (BKA) to above-knee amputation (AKA). For surviving patients, quality of life was determined by degree of ambulation, eg, outdoors, indoors only, or no ambulation; use of a prosthesis; and independence, eg, community housing or nursing facility. RESULTS: From August 1997 through March 2002, 154 patients (130 men; median age, 62 years) underwent 172 major amputations, 78 AKA and 94 BKA, because of either critical limb ischemia (87%) or diabetic neuropathy (13%). Thirty-day operative mortality was 10%. Mean follow-up was 14 months. Healing at 100 and 200 days, as determined with the Kaplan-Meier method, was 55% and 83%, respectively, for BKA, and 76% and 85%, respectively, for AKA. Twenty-three BKA and 16 AKA required additional operative revision, and 18 BKA ultimately were converted to AKA. Survival was 78% at 1 year and 55% at 3 years. Function in surviving patients at 10 and 17 months, respectively, was as follows: 21% and 29% of patients ambulated outdoors, 28% and 25% ambulated indoors only, and 51% and 46% of patients were nonambulatory; 32% and 42% of patients used prosthetic limbs; and 17% and 8% of patients who lived in the community before amputation required care in a nursing facility. CONCLUSIONS: We were surprised to find that vascular patients in a contemporary setting who require major lower extremity amputation and rehabilitation often remain independent despite infrequent prosthesis use and outdoor ambulation. Although any hope for postoperative ambulation in this population requires salvaging the knee joint, because of the morbidity incurred in both wound healing and rehabilitation efforts, aggressive effort should be reserved for selected patients at good risk. Ability to predict ambulation after BKA in the vascular population is poor.

Activities of Daily Living↗
PubMed2003

Evaluating effects of method of administration on Walking Impairment Questionnaire.

BACKGROUND: Intermittent claudication resulting from peripheral arterial disease (PAD) can substantially impair walking function. The Walking Impairment Questionnaire (WIQ) assesses patient self-reported difficulty in walking. Currently this questionnaire is validated for interviewer administration only. Since this can be burdensome in a large clinical trial, we examined the effects of alternative methods of administration on patient responses on the WIQ. METHODS: The WIQ, which consists of four subscales (pain severity, distance, speed, stairs), was modified to be self-administered or interviewer-administered by telephone. Patients with PAD were recruited from two sites and randomized into two groups: in group 1 the WIQ was self-administered, then telephone-administered; in group 2 the WIQ was telephone-administered, then self-administered. The two administrations occurred 4 to 7 days apart. Additional measures (SF-36, EQ-5D, and PAD symptom scale) and clinical data were included to further assess the validity of the WIQ and symptoms in patients with claudication. Telephone interviews were conducted by trained interviewers using standardized scripts. Two-week test-retest reliability was assessed for both the self-administered WIQ (group 1) and the telephone-administered WIQ (group 2). RESULTS: Sixty patients were recruited at two sites (n = 30 per group). Seventy-eight percent were men; mean patient age was 67.1 years; and 83% of patients were white. Mean duration of PAD symptoms was 6.8 years. No significant differences were observed in WIQ subscale scores between self administration and telephone administration. No interaction effects between order and method of administration were detected. Cronbach alpha for distance, speed, and stair-climbing subscales ranged from 0.82 to 0.94. Correlations among WIQ subscales and the symptom scale were good (r = -0.34 to -0.57). Correlations of WIQ subscales with physical health subscales of the SF-36 (r = 0.24-0.59) were higher than for mental health-related subscales (r = 0.08-0.26). CONCLUSIONS: The modified WIQ demonstrated good reliability and validity with both methods of administration. These results suggest that the self-administered and telephone-administered versions of the WIQ can be used reliably and efficiently in clinical trials.

Aged↗
PubMed2002

Cardiovascular disease mortality in Hispanics and non-Hispanic whites.

Despite a worse cardiovascular disease (CVD) risk profile, Hispanics have lower CVD mortality than non-Hispanic Whites in studies based on death certificates. This study examined 310 deaths that occurred between 1984 and 1998 among 1,862 Hispanic and non-Hispanic White participants in the San Luis Valley Diabetes Study, using medical records to classify cause of death. Among persons without diabetes, the age-adjusted all-cause mortality rate was 6.1/1,000 person-years in non-Hispanic Whites and 7.4/1,000 person-years in Hispanics. Among persons with diabetes, it was 24.3/1,000 person-years in non-Hispanic Whites and 21.9/1,000 person-years in Hispanics. Among nondiabetics, the age-adjusted CVD mortality rate was 2.5/1,000 person-years in non-Hispanic Whites and 1.6/1,000 person-years in Hispanics. Among diabetics, it was 12.9/1,000 person-years in non-Hispanic Whites and 8.8/1,000 person-years in Hispanics. Among nondiabetics, the adjusted hazard ratio for CVD death in Hispanics compared with non-Hispanic Whites was 0.65 (95% confidence interval (CI): 0.34, 1.23). The hazard ratio for coronary heart disease death was 0.95 (95% CI: 0.35, 2.59). Among diabetics, the hazard ratio for CVD death, after adjustment for conventional and diabetes risk factors, was 0.44 (95% CI: 0.26, 0.74), and for coronary heart disease death it was 0.43 (95% CI: 0.21, 0.91). A statistically significant decreased risk of CVD death was observed only in male Hispanics with diabetes. Competing mortality or factors that interact with diabetes may explain these differences.

Age Distribution↗
PubMed2002

Current medical therapies for patients with peripheral arterial disease: a critical review.

There is a paucity of trials that specifically evaluate the benefits of cardiovascular risk reduction therapies in patients with peripheral arterial disease. We therefore sought to describe the data supporting the use of therapies for lowering cardiovascular risk, preventing ischemic events, as well as managing intermittent claudication, in these patients. A search for randomized, placebo-controlled trials in peripheral arterial disease was conducted using Medline and reference lists of relevant articles. These trials served as the primary sources of data and treatment recommendations, while observational studies and case series were included as sources of commonly accepted treatment recommendations that were not fully supported by the randomized trial. Data from the primary sources support the use of antiplatelet therapy and, potentially, of angiotensin-converting enzyme inhibitors, for preventing ischemic events. In contrast, the evidence demonstrates a nonsignificant trend for treating dyslipidemia to prevent mortality and does not specifically support intensive glycemic control in persons with diabetes or estrogen use in these patients. However, observational data and data derived from trials in persons with other manifestations of cardiovascular disease may be generalized to support the importance of treating key risk factors, such as smoking, diabetes, dyslipidemia, and hypertension. Data supporting the use of estrogen to reduce cardiovascular risk are less clear. Studies do demonstrate improvement in walking ability resulting from exercise rehabilitation programs, as well as from use of cilostazol and, to a more modest degree, pentoxifylline. The consensus is to treat risk factors of peripheral arterial disease patients similarly to patients with other manifestations of atherosclerosis and to use exercise rehabilitation or cilostazol to treat the subset of patients with claudication.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2002

Treatment of peripheral arterial disease.

Peripheral arterial disease (PAD) is a manifestation of systemic atherosclerosis strongly associated with cardiovascular (CV) morbidity and mortality. Approximately 12% of the US adult population is affected. Despite its prevalence, the disease has received little attention from clinicians. The primary causes of death in patients with PAD are myocardial infarction and stroke; thus, current treatment strategies for symptomatic PAD include aggressive modification of risk factors for CV disease such as cessation of smoking, treatment of hypertension and diabetes, and normalization of low-density lipoprotein cholesterol levels. All patients with PAD should be receiving antiplatelet therapy to prevent ischemic events. Medical treatment for patients with claudication includes exercise rehabilitation and drug therapy. Although many therapies for claudication have been thoroughly investigated, research continues on new treatments. In contrast, more prospective, randomized trials are needed to evaluate various therapies for treating patients with PAD.

Arteriosclerosis↗
PubMed2002

Effect of cilostazol on treadmill walking, community-based walking ability, and health-related quality of life in patients with intermittent claudication due to peripheral arterial disease: meta-analysis of six randomized controlled trials.

OBJECTIVES: To assess whether cilostazol, a phosphodiesterase III inhibitor, improves treadmill and community-based walking ability and health-related quality of life (HQL) in patients with intermittent claudication resulting from peripheral arterial disease (PAD). DESIGN: Retrospective meta-analysis of data pooled from six Phase 3, multicenter, double-blind, placebo-controlled, parallel-group, randomized studies. SETTING: Patients were recruited from outpatient ambulatory medical care facilities. PARTICIPANTS: Patients' (n = 1,751) mean age +/- standard deviation was 65 +/- 9, and they had a history of PAD for 6 months or longer and an ankle brachial index (ABI) of 0.90 or less. INTERVENTION: Cilostazol 50 mg bid or 100 mg bid for 12, 16, or 24 weeks. MEASUREMENTS: ABI; maximal walking distance (MWD); pain-free walking distance on a graded and constant-load treadmill; and HQL, measured using the Walking Impairment Questionnaire (WIQ) and the Medical Outcomes Study Short Form-36 (SF-36). RESULTS: Maximal treadmill walking distance improved more in both cilostazol groups than in the placebo group (both P <.0001). WIQ and SF-36 physical summary scores improved significantly more with cilostazol than with placebo (for instance, WIQ distance score, P <.0001 and SF-36 physical summary score, P <.0001, comparing persons taking cilostazol with controls). Improved MWD correlated with improvements in WIQ (correlation with distance score, r = 0.34, P <.0001) and SF-36 physical summary scores (r = 0.29, P <.0001). CONCLUSIONS: Treatment with cilostazol was associated with greater improvements in community-based walking ability and HQL in patients with intermittent claudication than treatment with placebo. These improvements correlated with increased MWD. This analysis of effects of cilostazol on improving walking ability in persons with claudication is the first cilostazol study focused on community-based measures of functional status and HQL. Questionnaires assessing walking ability and HQL provide important patient-based information about clinical outcomes of claudication therapy.

Aged↗
PubMed2002

Clinical and demographic predictors of exercise capacity in end-stage renal disease.

Patients on maintenance hemodialysis therapy for end-stage renal disease have reduced exercise tolerance. Multiple processes related to uremia and hemodialysis have been implicated in the pathophysiology of this impairment. However, limited data are available to identify the separate and combined effects of clinical factors on the degree of impairment for individuals within this population. For this purpose, data from 193 patients who had undergone exercise testing for two clinical trials were retrospectively analyzed. Univariate and multiple linear regression analyses were used to identify demographic and clinical correlates of peak exercise oxygen uptake (VO2). Peak VO2 averaged 18.5 +/- 6.4 mL/min/kg. On univariate analysis, peak VO2 correlated positively with male sex and hemoglobin, serum albumin, and serum creatinine concentrations and correlated negatively with dialytic age and diagnosis of diabetes or chronic heart failure. In a multiple linear regression model, sex, hemoglobin concentration, age, and diagnosis of diabetes each remained statistically significant. Together, factors included in the model accounted for 41% of the variability in peak VO2 (P = 0.0001). Among factors not correlating significantly with peak VO2 were resting blood pressure, serum carnitine level, and urea clearance assessed by Kt/V. Findings show the range of exercise impairment among clinically stable ambulatory hemodialysis patients, which may be sufficient to interfere with normal daily activities for many of these patients. Although this impairment may be broadly attributable to physiological consequences of uremia, the degree of impairment for individual patients is predicted by demographic factors, coexistent disease, and factors potentially modified by medical therapeutics.

Adult↗
PubMed2002

Pharmacologic therapy for peripheral arterial disease and claudication.

Peripheral arterial disease (PAD) is a common manifestation of systemic atherosclerosis that is associated with a high risk of cardiovascular mortality and significant limitation in function because of limb ischemia. Patients with PAD should be considered to have significant coronary and cerebral arterial disease that requires aggressive risk factor management, including the prescription of antiplatelet drugs, to lower the subsequent risk of myocardial infarction, stroke, and death. In the population with PAD, level 1 and level 2 evidence supports the use of statin drugs for lipid management, angiotensin-converting enzyme-1 inhibitors for blood pressure control, and aspirin or clopidogrel as antiplatelet agents. Once this is accomplished, the severity of limb symptoms should be assessed, and a structured exercise program or the selected use of drugs such as cilostazol to treat claudication should be prescribed. In patients primarily considered for surgical treatment, antiplatelet and anticoagulant drug therapy can be used as a means of promoting graft patency, and beta-adrenergic blockers can be used as a means of reducing the perioperative risks associated with vascular surgery.

Anticoagulants↗
PubMed2002

Peripheral arterial disease: medical care and prevention of complications.

Peripheral arterial disease (PAD) is a common but under-recognized problem affecting older patients. Intermittent claudication is the most frequent symptom of PAD, although the diagnosis of PAD is often overlooked until the patient presents with limb-threatening ischemia. Importantly, PAD is a marker for generalized atherosclerosis and is closely associated with coronary and cerebrovascular disease. The severity of PAD has been correlated with an increased risk of myocardial infarction, stroke, and cardiovascular death. The recognition and diagnosis of PAD, combined with its appropriate medical management, may well reduce the overall risk of cardiovascular morbidity. When diagnosed early, both exercise and pharmacotherapy can ameliorate symptoms of claudication, augment functional performance, and improve quality of life.

Aged↗
PubMedDate not supplied

Peripheral arterial disease is not associated with an increased prevalence of intradialytic cramps in patients on maintenance hemodialysis.

BACKGROUND/AIMS: Peripheral arterial disease (PAD) has been suggested as a contributing factor to the development of intradialytic muscle cramps in patients on maintenance hemodialysis. METHODS: To test this hypothesis, 122 patients from two dialysis centers were studied. The presence of PAD was determined by measurement of the ankle-brachial index (ABI) in the lower extremities of patients pre- and postdialysis. The experience of intradialytic cramps was assessed using patient history and review of medical records. RESULTS: PAD defined as a predialysis ABI < or =0.90 had an overall prevalence of 16.4% among patients studied. The prevalence of PAD was age-dependent, reaching 37.5% in patients 80-89 years old. Intradialytic muscle cramps were common, with 52.1% of patients reporting cramps within the previous two months, but there was no relationship between cramps during dialysis and PAD (p > 0.05). CONCLUSIONS: PAD was common in hemodialysis patients, but there was no association between the presence of PAD and the prevalence of intradialytic muscle cramps.

Adult↗