Jean Nappi

Evaluation of treatment with direct thrombin inhibitors in patients with heparin-induced thrombocytopenia.

Study Objective. To evaluate the efficacy, safety, and associated costs of anticoagulation with argatroban, bivalirudin, and lepirudin for managing patients with heparin‐induced thrombocytopenia (HIT) or presumed HIT.

Continuous Versus Intermittent Infusion of Furosemide in Acute Decompensated Heart Failure

BACKGROUND Despite advances in the treatment of chronic ambulatory heart failure, hospitalization rates for acute decompensated heart failure (ADHF) remain high. Although loop diuretics are used in nearly all patients with ADHF to relieve congestive symptoms, optimal dosing strategies remain poorly defined. METHODS AND RESULTS This was a prospective, randomized, parallel-group study comparing the effectiveness of continuous intravenous (cIV) with intermittent intravenous (iIV) infusion of furosemide in 56 patients with ADHF. The dose and duration of furosemide as well as concomitant medications to treat ADHF were determined by physician preference. The primary end point of the study was net urine output (nUOP)/24 hours. Safety measures including electrolyte loss and hemodynamic instability were also assessed. Twenty-six patients received cIV and 30 patients received iIV dosing. The mean nUOP/24 hours was 2098+/-1132 mL in patients receiving cIV versus 1575+/-1100 mL in the iIV group (P=.086). The cIV group had significantly greater total urine output (tUOP) with 3726+/-1121 mL/24 hours versus 2955+/-1267 mL/24 hours in the iIV group (P=.019) and tUOP/mg furosemide with 38.0+/-31.0 mL/mg versus 22.2+/-12.5 mL/mg (P=.021). Mean weight loss was not significantly different between the groups. The cIV group experienced a shorter length of hospital stay (6.9+/-3.7 versus 10.9+/-8.3 days, P=.006). There were no differences in safety measures between the groups. CONCLUSIONS The cIV of furosemide was well tolerated and significantly more effective than iIV for tUOP. In addition, continuous infusion appears to provide more efficient diuresis.

Bosentan for the Treatment of Pulmonary Arterial Hypertension

OBJECTIVE: To describe the pharmacology, pharmacokinetics, efficacy, and safety of bosentan in the treatment of pulmonary arterial hypertension (PAH). DATA SOURCES: A MEDLINE and Current Contents search (1966–June 2002) of the English-language literature was conducted to identify published dose-ranging, pharmacokinetic, pivotal efficacy trials and review articles of bosentan and endothelin antagonists. Additional references were identified from the bibliographies of the retrieved articles. DATA SYNTHESIS: Bosentan is the first orally active, nonpeptide endothelin receptor antagonist approved by the Food and Drug Administration for use in patients with World Health Organization (WHO) functional class III and IV PAH. Titrated to a dose of 125 mg twice daily, bosentan produces pulmonary vasodilation, improving cardiopulmonary hemodynamics leading to better outcomes for patients. It is metabolized primarily by the hepatic system via the cytochrome P450 enzyme pathway and eliminated by biliary excretion. Bosentan is an inducer of the isoenzymes CYP3A4 and 2C9. It possesses a unique pharmacokinetic profile with a terminal elimination half-life of approximately 5 hours, yet steady-state plasma concentrations are not achieved for 3–5 days as a result of enhanced drug clearance and autoinduction following multiple daily dosing. The major adverse effects of bosentan are the potential for birth defects and hepatotoxicity. CONCLUSIONS: The use of bosentan in patients with WHO functional class III and IV PAH is associated with improved exercise tolerance, cardiopulmonary hemodynamics, and increased time to clinical worsening when compared with placebo. It offers significant advantage in ease of administration and quality of life compared with epoprostenol therapy, with similar efficacy.

New Recommendations from the 1999 American College of Cardiology/American Heart Association Acute Myocardial Infarction Guidelines

OBJECTIVE: To review literature relating to significant changes in drug therapy recommendations in the 1999 American College of Cardiology (ACC)/American Heart Association (AHA) guidelines for treating patients with acute myocardial infarction (AMI). DATA SOURCES: 1999 ACC/AHA AMI guidelines, English-language clinical trials, reviews, and editorials researching the role of drug therapy and primary angioplasty for AMI that were referenced in the guidelines were included. Additional data published in 2000 or unpublished were also included if relevant to interpretation of the guidelines. STUDY SELECTION: The articles selected influence AMI treatment recommendations. DATA SYNTHESIS: Many clinicians and health systems use the ACC/AHA AMI guidelines to develop treatment plans for AMI patients. This review highlights important changes in AMI drug therapy recommendations by reviewing the results of recent clinical trials. Insights into evolving drug therapy strategies that may impact future guideline development are also described. CONCLUSIONS: Several changes in drug therapy recommendations were included in the 1999 AMI ACC/AHA guidelines. There is emphasis on administering fibrin-specific thrombolytics secondary to enhanced efficacy. Selection between fibrin-specific agents is unclear at this time. Low response rates to thrombolytics have been noted in the elderly, women, patients with heart failure, and those showing left bundle-branch block on the electrocardiogram. These patient groups should be targeted for improved utilization programs. The use of glycoprotein (GP) IIb/IIIa receptor inhibitors in non-ST—segment elevation MI was emphasized. Small trials combining reduced doses of thrombolytics with GP IIb/IIIa receptor inhibitors have shown promise by increasing reperfusion rates without increasing bleeding risk, but firm conclusions cannot be made until the results of larger trials are known. Primary percutaneous coronary intervention (PCI) trials suggest lower mortality rates for primary PCI when compared with thrombolysis alone. However, primary PCI, including coronary angioplasty, is only available at approximately 13% of US hospitals, making thrombolysis the preferred strategy for most patients. Clopidogrel has supplanted ticlopidine as the recommended antiplatelet agent for patients with aspirin allergy or intolerance following reports of a better safety profile. The recommended dose of unfractionated heparin is lower than previously recommended, necessitating a separate nomogram for patients with acute coronary syndromes. Routine use of warfarin, either alone or in combination with aspirin, is not supported by clinical trials; however, warfarin remains a choice for antithrombotic therapy in patients intolerant to aspirin. β -Adrenergic receptor blockers continue to be recommended, and emphasis is placed on improving rates of early administration (during hospitalization), even in patients with moderate left ventricular dysfunction. New recommendations for drug treatment of post-AMI patients with low high-density lipoprotein cholesterol and/or elevated triglycerides are included, with either niacin or gemfibrozil recommended as an option. Supplementary antioxidants are not recommended for either primary or secondary prevention of AMI, with new data demonstrating lack of efficacy for vitamin E in primary prevention. Estrogen replacement therapy or hormonal replacement therapy should not be initiated solely for prevention of cardiovascular disease, but can be continued in cardiovascular patients already taking long-term therapy for other reasons. Bupropion has been added as a new treatment option for smoking cessation. As drug therapy continues to evolve in treating AMI, more frequent updates of therapy guidelines will be necessary.

Rhabdomyolysis with Concurrent Atorvastatin and Diltiazem

OBJECTIVE: To report a case of rhabdomyolysis and acute hepatitis associated with the coadministration of atorvastatin and diltiazem. CASE SUMMARY: A 60-year-old African American man with a significant past medical history presented to the emergency department with acute renal failure secondary to rhabdomyolysis. In addition, liver enzymes were elevated to greater than 3 × normal. The only change in medication was the initiation of diltiazem 3 weeks earlier for atrial fibrillation to a complicated medication regimen that included atorvastatin. DISCUSSION: Rhabdomyolysis has been reported in patients receiving hydroxymethylglutaryl coenzyme A (HMG-CoA) reductase inhibitors when coadministered with agents that may inhibit their metabolism. Atorvastatin is the most potent of this class of agents currently available and is commonly used in the treatment of hyperlipidemia. Rhabdomyolysis resulting from the drug interaction between diltiazem and other HMG-CoA reductase inhibitors has been described in the literature. However, no report has specifically associated this adverse event with atorvastatin and diltiazem. We describe a patient with a complex medication regimen who was admitted for rhabdomyolysis and accompanying acute renal failure, along with acute hepatitis, thought to be secondary to a drug interaction between atorvastatin and diltiazem. CONCLUSIONS: While optimizing the patients lipid profile should be the primary factor in choosing one statin over another, the potential for drug interactions requires close attention. All patients beginning HMG-CoA reductase inhibitor therapy should be counseled regarding the signs and symptoms of muscle injury; particular attention should be paid to those patients who are taking medications that may interact.

Myocardial Infarction in Women: A Critical Appraisal of Gender Differences in Outcomes

In every year since 1984, cardiovascular disease has claimed the lives of more women than men. Data from randomized trials indicate that gender contributes to increased mortality after myocardial infarction independent of other risk factors, but additional confounding variables cannot be discounted. Data from registry databases indicate that women are less likely to receive medically proven therapies for myocardial infarction. Women experience more vague symptoms, which may account for underuse of effective therapies. In addition, they may benefit less from thrombolytic therapy than men. Increased use of thrombolytic therapy has resulted in a continued decrease in cardiovascular deaths for men, but not for women. It is unclear if this disparity is a result of inequitable access to therapy or decreased efficacy of these agents in women.

Aldosterone and aldosterone receptor antagonists in patients with chronic heart failure

Aldosterone is a mineralocorticoid hormone synthesized by the adrenal glands that has several regulatory functions to help the body maintain normal volume status and electrolyte balance. Studies have shown significantly higher levels of aldosterone secretion in patients with congestive heart failure compared with normal patients. Elevated levels of aldosterone have been shown to elevate blood pressure, cause left ventricular hypertrophy, and promote cardiac fibrosis. An appreciation of the true role of aldosterone in patients with chronic heart failure did not become apparent until the publication of the Randomized Aldactone Evaluation Study. Until recently, the use of aldosterone receptor antagonists has been limited to patients with severe heart failure and patients with heart failure following myocardial infarction. The Eplerenone in Mild Patients Hospitalization and Survival Study in Heart Failure (EMPHASIS-HF) study added additional evidence to support the expanded use of aldosterone receptor antagonists in heart failure patients. The results of the EMPHASIS-HF trial showed that patients with mild-to-moderate (New York Heart Association Class II) heart failure had reductions in mortality and hospitalizations from the addition of eplerenone to optimal medical therapy. Evidence remains elusive about the exact mechanism by which aldosterone receptor antagonists improve heart failure morbidity and mortality. The benefits of aldosterone receptor antagonist use in heart failure must be weighed against the potential risk of complications, ie, hyperkalemia and, in the case of spironolactone, possible endocrine abnormalities, in particular gynecomastia. With appropriate monitoring, these risks can be minimized. We now have evidence that patients with mild-to-severe symptoms associated with systolic heart failure will benefit from the addition of an aldosterone receptor antagonist to the standard therapies of angiotensin-converting enzyme inhibitors and beta-blockers. This review will address the pharmacologic basis of aldosterone receptor antagonists in patients with heart failure and the clinical impact of this therapy.

Possible Pharmacokinetic Interaction with Quinidine: Ciprofloxacin or Metronidazole?

OBJECTIVE: To discuss a potential pharmacokinetic interaction between quinidine, ciprofloxacin, and metronidazole. CASE SUMMARY: A 51-year-old black woman was admitted for shortness of breath, abdominal pain, and atrial fibrillation. Procainamide and diltiazem were begun for the atrial fibrillation and ciprofloxacin and metronidazole for suspected diverticulitis. The therapy was switched to quinidine on day 5 because of adverse events associated with procainamide. A trough serum quinidine concentration (SQC) on day 7 was 6.3 μg/mL (normal 2–5) with normal QT and QTc intervals. On day 8, the patient was discharged in normal sinus rhythm. She took her last doses of antibiotics on day 15 and a follow-up SQC on day 18 was 2.3 μg/mL. DISCUSSION: The possible explanations for the changes in SQCs include: (1) laboratory error, (2) compliance with medication regimen, and (3) altered hepatic metabolism. The first two are not likely in this case. The laboratory verified the elevated SQC and the patient had her prescriptions refilled within appropriate time limits. The third explanation seems more plausible. Quinidine is metabolized by the hepatic mixed-function oxidase system, specifically cytochrome P450 (CYP) 3A4. We found that metronidazole has been shown to inhibit CYP3A activity and ciprofloxacin has been shown to inhibit certain isozymes in the cytochrome P450 system as well. CONCLUSIONS: When metronidazole and ciprofloxacin are administered concomitantly with quinidine, clinicians should be aware of this potential interaction. Quinidine concentrations should be monitored and patients should be assessed for signs and symptoms of quinidine toxicity.

Type 2 Diabetes Mellitus and Heart Failure

Diabetes mellitus and heart failure are common comorbidities, and their prevalence has increased significantly over the past decade. We examined the relationships between diabetes and heart failure, the effect of commonly prescribed antidiabetic drugs on the development of heart failure, and the benefits and risks of recommended heart failure therapies in patients with diabetes. Compared with patients with heart failure who do not have diabetes, patients with both diabetes and heart failure have a poorer prognosis, including a 1.5‐2‐fold higher risk of mortality. Based on the results of randomized controlled trials, insulin and sulfonylureas do not appear to protect against or contribute to the development of new‐onset heart failure, whereas metformin may modestly reduce the risk. The use of metformin in patients with established heart failure is controversial; retrospective analyses have shown that metformin may have a beneficial effect on outcomes, but there are no prospective, randomized clinical trials to support its use in this population. The thiazolidinediones, however, contribute to the development of heart failure and increase the risk of heart failure exacerbations particularly when used in combination with insulin. Recommendations for the treatment of symptomatic heart failure in patients with diabetes have been largely derived from post hoc analyses or preplanned subgroup analyses in landmark clinical trials. The data clearly support the use of angiotensin‐converting enzyme inhibitors and angiotensin II receptor blockers for both the prevention and treatment of symptomatic heart failure in patients with diabetes. Despite concerns regarding the potential risks of β‐blockers in patients with diabetes, these drugs have a clear mortality benefit in patients with stages B and C heart failure. Therefore, patients with diabetes should not be denied β‐blocker therapy unless there is a clear contraindication. Likewise, aldosterone receptor antagonists should be added to standard therapies in patients with stages C and D heart failure. Future heart failure studies should include a sufficiently large diabetes cohort to conduct meaningful preplanned subgroup analyses that examine the effect of proposed treatments on both heart failure‐related and diabetes‐related outcomes.

Barriers to Clopidogrel Adherence Following Placement of Drug-Eluting Stents

BACKGROUND Nonadherence to clopidogrel after drug-eluting stent (DES) placement is associated with in-stent thrombosis and adverse cardiac events. OBJECTIVE To identify the incidence of and barriers associated with nonadherence to clopidogrel in patients receiving DES. METHODS Patients who received a DES between March 1, 2004, and August 31, 2005, from a single academic medical center were eligible. Telephone interviews were conducted 6 or more months following discharge. Nonadherence was defined as premature discontinuation of or less than 80% adherence to clopidogrel. Patients were asked to identify barriers to adherence. Differences between adherent and nonadherent patients were analyzed using chi(2) and t-test analysis. RESULTS Of the 674 patients identified, 257 (38%) participated. The nonadherence rate was 20%. The majority (58%) of nonadherent patients discontinued therapy prematurely. Patients identified the main reason for discontinuation as medical barriers (18.56%), including perceived adverse effects (9.28%). The incidence of rash was higher in patients who were nonadherent (12% vs 4%; p = 0.049). Overall, 49% of patients recalled receiving discharge counseling regarding adverse effects. A financial barrier was identified by 22 (42%) patients in the nonadherent and 73 (36%) in the adherent group, of whom 64% and 52%, respectively, reported having insurance coverage for medications. Adherent patients reported higher copays (