Rapid assessment of glycoprotein IIb/IIIa blockade with the platelet function analyzer (PFA-100) during percutaneous coronary intervention

BACKGROUND: The platelet function analyzer PFA-100 (Dade Behring, Miami, Fla) evaluates platelet function by determining the time to occlusion of an aperture in a membrane coated with collagen and adenosine diphosphate or epinephrine as whole blood flows under shear stress conditions. Platelet aggregation causes aperture occlusion, and results are reported as closure time (CT). Interindividual variability is observed in the level of platelet inhibition achieved with use of the current abciximab dosing regimen (0.25-mg/kg bolus + 10-microg/min infusion for 12 hours). The relationships between specific levels of platelet inhibition and clinical efficacy and safety have not been fully established. METHODS AND RESULTS: We prospectively studied platelet function in 27 patients receiving abciximab during percutaneous coronary intervention. This evaluation included determinations of platelet-rich plasma aggregometry, receptor occupancy studies (D3 assay), and CT measurements at baseline and 10 minutes, 4 hours, 12 hours, and 24 hours after the bolus. All patients received abciximab, aspirin, and heparin; patients undergoing coronary stent implantation received aspirin and ticlopidine after the procedure. CT results were reported within 10 minutes after initiation of testing. For 96% of patients, CT was 300 seconds (maximum CT) immediately after abciximab bolus and remained so throughout the infusion. At 24 hours we observed variable recovery from platelet inhibition and in 72% of patients CT returned to normal (< or =130 seconds). CONCLUSIONS: Findings with the PFA-100 were similar to results observed with platelet aggregometry and receptor occupancy measurements. Most patients treated with abciximab exhibit normalized platelet function at 24 hours despite moderate levels of receptor occupancy, suggesting dissociation between occupancy and function.     

The impact of pioglitazone on glycemic control and atherogenic dyslipidemia in patients with type 2 diabetes mellitus

BACKGROUND: To evaluate the glycemic control, lipid effects, and safety of pioglitazone in patients with type 2 diabetes mellitus. DESIGN AND METHODS: Patients (n = 197) with type 2 diabetes mellitus, a hemoglobin A1c (HbA1c) > or = 8.0%, fasting plasma glucose (FPG) > 7.7 mmol/l (140 mg/dl), and C-peptide > 0.331 nmol/l (1 ng/ml) were enrolled in this 23-week multi-center (27 sites), double-blind clinical trial and randomized to receive either a placebo or pioglitazone HCl 30 mg (pioglitazone), administered once daily, as monotherapy. Patients were required to discontinue all anti-diabetic medications 6 weeks before receiving study treatment. Efficacy parameters included HbA1c fasting plasma glucose (FPG), serum C-peptide, insulin, triglycerides (Tg), and cholesterol (total cholesterol [TC], high-density lipoprotein-cholesterol [HDL-C], low-density lipoprotein-cholesterol [LDL-C]). Adverse event rates, serum chemistry, and physical examinations were recorded. RESULTS: Compared with placebo, pioglitazone significantly (P= 0.0001) reduced HbA1c (-1.37% points), FPG (-3.19 mmol/l; -57.5 mg/dl), fasting C-peptide (-0.076+/-0.022 nmol/l), and fasting insulin (-11.88+/-4.70 pmol/l). Pioglitazone significantly (P < 0.001) decreased insulin resistance (HOMA-IR; -12.4+/-7.46%) and improved beta-cell function (Homeostasis Model Assessment (HOMA-BCF); +47.7+/-11.58%). Compared with placebo, fasting serum Tg concentrations decreased (-16.6%; P = 0.0178) and HDL-C concentrations increased (+12.6%; P= 0.0065) with pioglitazone as monotherapy. Total cholesterol and LDL-C changes were not different from placebo. The overall adverse event profile of pioglitazone was similar to that of placebo, with no evidence of drug-induced elevations of serum alanine transaminase (ALT) concentrations or hepatotoxicity. CONCLUSIONS: Pioglitazone improved insulin resistance and glycemic control, as well as Tg and HDL-C - which suggests that pioglitazone may reduce cardiovascular risk for patients with type 2 diabetes.     

Newly detected atrial fibrillation and compliance with antithrombotic guidelines

BACKGROUND: Guidelines recommend the use of antithrombotic therapy for stroke prevention in patients with atrial fibrillation (AF), but compliance with such guidelines has not been widely studied among patients with newly detected AF. Our objective was to assess compliance with antithrombotic guidelines and to identify patient characteristics associated with warfarin use. METHODS: A population-based study of newly detected AF (patient age, 30-84 years) was conducted within a large health plan. Cardiovascular disease risk factors, comorbid conditions, medication use, and international normalized ratios were abstracted from the medical record. Patients were stratified by embolic risk according to American College of Chest Physicians (ACCP) criteria. We analyzed the proportion of patients with AF receiving warfarin or aspirin (> or =325 mg/d) during the 6 months following AF. Relative risk regression estimated the association of risk factors and patient characteristics with warfarin use. RESULTS: Overall, 73% of patients (418/572) with newly detected AF had evidence of antithrombotic use after AF onset. Among the 76% (437/572) of patients with AF at high risk for stroke, 59% (257/437) used warfarin, 28% (123/437) used aspirin, and 24% (104/437) used neither. The major predictor of warfarin use was AF classification; intermittent or sustained AF had relative risks for warfarin use of 2.8 (95% confidence interval, 2.2-3.6) and 2.9 (95% confidence interval, 2.2-3.7), respectively, compared with transitory AF. CONCLUSIONS: Three quarters of the patients with newly detected AF received antithrombotic therapy, yet many at high risk of stroke did not receive warfarin. Atrial fibrillation classification, rather than stroke risk factors, was strongly associated with warfarin use.     

Management of heatstroke and heat exhaustion

Heat exhaustion and heatstroke are part of a continuum of heat-related illness. Both are common and preventable conditions affecting diverse patients. Recent research has identified a cascade of inflammatory pathologic events that begins with mild heat exhaustion and, if uninterrupted, can lead eventually to multiorgan failure and death. Heat exhaustion is characterized by nonspecific symptoms such as malaise, headache, and nausea. Treatment involves monitoring the patient in a cool, shady environment and ensuring adequate hydration. Untreated heat exhaustion can progress to heatstroke, a much more serious illness involving central nervous system dysfunction such as delirium and coma. Other systemic effects, including rhabdomyolysis, hepatic failure, arrhythmias, disseminated intravascular coagulation, and even death, are not uncommon. Prompt recognition and immediate cooling through evaporation or full-body ice-water immersion are crucial. Physicians also must monitor electrolyte abnormalities, be alert to signs of renal or hepatic failure, and replace fluids in patients with heatstroke. Most experts believe that physicians and public health officials should focus greater attention on prevention. Programs involving identification of vulnerable individuals, dissemination of information about dangerous heat waves, and use of heat shelters may help prevent heat-related illness. These preventive measures, when paired with astute recognition of the early signs of heat-related illness, can allow physicians in the ambulatory setting to avert much of the morbidity and mortality associated with heat exhaustion and heatstroke.     

Risk of myocardial infarction attributable to elevated levels of total cholesterol among hypertensives

BACKGROUND: Although cholesterol is an important risk factor for coronary heart disease (CHD) among hypertensives, the burden of CHD among hypertensives that may be due to elevated cholesterol has not been well documented. This study aimed to estimate the proportion of incident myocardial infarction (MI) among hypertensives that may be attributable to elevated total cholesterol, and to investigate how well the National Cholesterol Education Program Adult Treatment Panel III (ATP III) classification method represents risk of MI among hypertensives. METHODS: A population-based, case-control study of patients aged 30 to 79 years enrolled in a health maintenance organization, treated pharmacologically for hypertension, and who were not using lipid-lowering medication. Cases were diagnosed with an incident fatal or nonfatal MI between 1986 and 2000 (n = 1535). Controls were randomly sampled and frequency-matched to cases by sex, 10-year age category, and year of event (n = 3743). Subjects' most recent total cholesterol values were categorized according to ATP III guidelines. RESULTS: Overall, 31% (95% confidence interval: 23-39) of incident MIs among hypertensives could be explained by total cholesterol level above the optimal level of 200 mg/dL. Among participants in the highest ATP III risk stratum, 41% (95% confidence interval: 9-62) of the incident MIs were attributable to total cholesterol levels >160 mg/dL, but total cholesterol >or=200 mg/dL accounted for the majority of these excess events. CONCLUSIONS: The ATP III risk stratification approach improves detection of the CHD burden due to elevated total cholesterol among hypertensives at highest risk. A strategy to improve cholesterol control in hypertensive patients might prevent a substantial part of the burden of morbidity and mortality from MI.     

The role of BAL in the diagnosis of pulmonary mucormycosis

Five patients with pulmonary mucormycosis diagnosed during life are described. All had underlying predisposing conditions: either posttransplant or hematologic malignancies. In all cases, the diagnosis was made using fiberoptic bronchoscopy. In three patients, BAL was diagnostic. In two of these patients, the diagnosis was made by identifying the typical hyphae of mucormycosis in the BAL fluid alone. Transbronchial biopsy was diagnostic in three patients. Treatment was based on IV antifungal chemotherapy together with surgical removal of involved lung tissue whenever feasible. The clinical outcome of these patients was dismal and was determined primarily by the underlying condition.     

Once-daily treatment of patients with hypertension: a placebo-controlled study of amlodipine and benazepril vs amlodipine or benazepril alone

OBJECTIVE: To compare the efficacy, tolerability, and safety of once-daily therapy with amlodipine 5 mg/benazepril 10 mg vs amlodipine 5 mg, benazepril 10 mg, and placebo. DESIGN: Randomised, double-blind, placebo-controlled, parallel-group, multicentre trial. SETTING: Twenty-two clinical centres, including private practice groups and academic research clinics.Patients: A total of 530 patients between 21 and 80 years of age with essential hypertension were screened for the study, and 454 were randomised to treatment with amlodipine 5 mg/benazepril 10 mg, amlodipine 5 mg, benazepril 10 mg, or placebo for 8 weeks. RESULTS: Amlodipine 5 mg/benazepril 10 mg produced greater reductions from baseline in sitting diastolic blood pressure than amlodipine 5 mg (P < 0.03), benazepril 10 mg (P < 0.001), and placebo (P < 0.001). The response rate in the amlodipine 5-mg/benazepril 10-mg treatment group (66.4%) was better than that observed in the amlodipine 5-mg (50.0% P < 0.02), benazepril 10-mg (38.3% P < 0.001), and placebo (24.4% P < 0.001) groups. There was no significant difference in heart rate among the four groups. The incidence of oedema in the amlodipine 5-mg/benazepril 10-mg (1.7%) group was somewhat less than that in the amlodipine 5-mg (4.5%) group. CONCLUSIONS: Therapy with amlodipine 5 mg/benazepril 10 mg was well tolerated and was superior to amlodipine 5 mg, benazepril 10 mg, and placebo in reducing sitting diastolic blood pressure in patients with essential hypertension.     

Rationale and design of the Valsartan Heart Failure Trial: a large multinational trial to assess the effects of valsartan, an angiotensin-receptor blocker, on morbidity and mortality in chronic congestive heart failure.

BACKGROUND: To investigate the role of persistent angiotensin activity despite angiotensin-converting enzyme inhibitor therapy in the progression of heart failure, the Valsartan Heart Failure Trial has been designed to investigate the effect of the angiotensin-receptor blocker, valsartan, on morbidity and mortality. METHODS AND RESULTS: Nearly 5,000 patients with New York Heart Association classes II to IV heart failure, while receiving all standard therapy, are being randomized to treatment with valsartan, 160 mg twice daily, or placebo in a worldwide study. Follow-up will be continued until 906 deaths have been recorded. Additional end points will include the need for hospitalization, other major morbid events, quality--of life measurement, changes in neurohormone levels, and changes in left ventricular size and function. Substudies will explore exercise tolerance, arrhythmias, and magnetic resonance imaging. CONCLUSION: This study should help establish the role of angiotensin-receptor blockade in the treatment of heart failure.