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Biomedical subjects

Michael A Crouch

Publications and source records attributed to Michael A Crouch.

12 recordsLinked to original sources
PubMed2006

Drug therapy recommendations from the 2005 ACC/AHA guidelines for treatment of chronic heart failure.

OBJECTIVE: To review and discuss key aspects of the drug therapy recommendations in the American College of Cardiology (ACC)/American Heart Association (AHA) 2005 Guideline Update for the Diagnosis and Management of Chronic Heart Failure (HF) in the Adult. DATA SOURCES: Data were obtained from the ACC/AHA 2005 Guideline Update for Chronic HF. English-language clinical trials, observational studies, and pertinent review articles evaluating the pharmacotherapy of chronic HF were identified, based on MEDLINE searches through January 2006. STUDY SELECTION: Articles presenting information that impacts the evidence base for recommendations regarding the use of various drug therapies in patients with chronic HF were evaluated. DATA SYNTHESIS: The ACC/AHA 2005 Guideline Update for HF provides revised, evidence-based recommendations for the treatment of chronic HF. The new guidelines are based on a staging system that recognizes both the development and progression of HF. Recommendations are provided for 2 stages of patients (A and B) who do not yet have clinical HF but are clearly at risk and 2 stages (C and D) that include patients with symptomatic HF. The guidelines continue to emphasize the important role of neurohormonal blockade with angiotensin-converting enzyme inhibitors, angiotensin-receptor blockers, beta-adrenergic blockers, and aldosterone antagonists. Based on recent trials, updated recommendations address the roles of combination therapy and the selective addition of hydralazine and isosorbide dinitrate. Along with specific drug recommendations, information on the practical use of various drugs is provided. Although the guidelines primarily focus on HF due to systolic dysfunction, general recommendations are also provided for patients with preserved systolic function. CONCLUSIONS: The ACC/AHA 2005 Guideline Update provides evidence-based recommendations for healthcare professionals involved in the care of adults with chronic HF. Recent clinical trial findings have further clarified the evolving role of neurohormonal-blocking drugs in the prevention and treatment of HF.

American Heart Association↗
PubMed2006

Cost-effectiveness analysis of antithrombotic therapy in nonurgent percutaneous coronary intervention.

STUDY OBJECTIVE: To perform a cost-effectiveness analysis comparing three treatment approaches during nonurgent percutaneous coronary intervention (PCI): bivalirudin with provisional glycoprotein (GP) IIb-IIIa inhibitor therapy, unfractionated heparin (UFH) with eptifibatide, and UFH with abciximab. DESIGN: Literature-based decision model from an institutional perspective. DATA SOURCE: Patient data from the Randomized Evaluation in PCI Linking Angiomax to Reduced Clinical Events (REPLACE)-2 study and three other randomized controlled trials that included UFH and routine GP IIb-IIIa inhibitor (eptifibatide or abciximab) therapy. All included studies were comparable based on patient population, procedural techniques, and general treatment approaches. MEASUREMENTS AND MAIN RESULTS: We included patient populations undergoing contemporary nonurgent PCI to identify probabilities of success or complications (myocardial infarction, urgent revascularization, thrombocytopenia, and major or minor bleeding at 30 days). Costs were assigned to each outcome by incorporating diagnosis-related group-- and/or Current Procedural Terminology--associated costs, institutional drug acquisition costs, and unit replacement costs of platelets and red blood cells. In the base-case analysis, the use of bivalirudin with provisional GP IIb-IIIa inhibitor therapy dominated the UFH and planned GP IIb-IIIa inhibitor approach: UFH with eptifibatide was 74 US dollars more expensive and 1.2% less effective, and UFH with abciximab was 777 US dollars more expensive and 2.3% less effective. Sensitivity analyses indicated that the model results were robust, but also revealed that bivalirudin lost its cost-effectiveness, resulting in UFH with eptifibatide becoming more cost-effective, when two or more vials of bivalirudin were necessary in greater than 27% of cases or when the use of provisional GP IIb-IIIa inhibitor therapy exceeded 20%. CONCLUSION: This analysis indicates that bivalirudin with provisional GP IIb-IIIa inhibitor therapy is the most cost-effective antithrombotic treatment strategy in nonurgent PCI when its use and dosing are consistent with the REPLACE-2 trial.

Abciximab↗
PubMed2006

Evolving role of vasopressin in the treatment of cardiac arrest.

Sudden cardiac arrest is a major public heath problem, affecting more than 450,000 individuals annually. Response time and the initiation of cardiopulmonary resuscitation (CPR) remain the most important factors determining successful revival. During resuscitation, sympathomimetics are given to enhance cerebral and coronary perfusion pressures in an attempt to achieve restoration of spontaneous circulation. Epinephrine has been the preferred vasopressor since the inception of advanced cardiac life support, although the lack of definitive evidence regarding its effectiveness has created much controversy surrounding its use, including the optimum dosage. Vasopressin is an alternative vasopressor that, when given at high doses, causes vasoconstriction by directly stimulating smooth muscle V1 receptors. The 2000 American Heart Association (AHA) guidelines commented that vasopressin is a reasonable first-line vasopressor in patients with ventricular fibrillation or pulseless ventricular tachycardia. Since release of those guidelines, additional human studies support an expanded role for vasopressin, whereas other studies cast doubt regarding its efficacy compared with epinephrine. The AHA recently released revised guidelines for CPR and emergency cardiovascular care. The consensus was that vasopressors should remain a part of pulseless sudden cardiac arrest management, with epinephrine 1 mg every 3-5 minutes being the recommended adrenergic of choice. In these revised guidelines, the role of vasopressin expanded beyond previous recommendations, despite the recommendation being downgraded to class indeterminate. The guidelines comment that one dose of vasopressin 40 U may replace the first or second dose of epinephrine in all pulseless sudden cardiac arrest scenarios, including asystole and pulseless electrical activity. A consistent theme with all vasopressors in sudden cardiac arrest is that additional studies are necessary to clearly document greater efficacy compared with no treatment. Further evaluation is warranted to better assess the role of vasopressin in asystolic sudden cardiac arrest, as well as its use with epinephrine, and to determine its optimal timing of administration and potential synergistic effects.

Arginine Vasopressin↗
PubMed2006

Outcomes associated with vasoactive therapy in patients with acute decompensated heart failure.

STUDY OBJECTIVES: To describe the clinical management of acute decompensated heart failure (ADHF) in patients receiving intravenous treatment with dobutamine, milrinone, or nesiritide, and to evaluate differences, based on treatment received, in the in-hospital mortality rate, length of stay (LOS), total health care costs, and 30-day hospital readmission rate. DESIGN: Retrospective cohort analysis. DATA SOURCE: University HealthSystem Consortium (UHC) Clinical Database Pharmacy, a database with information from 32 academic hospitals. PATIENTS: Two thousand one hundred thirty patients with ADHF who received dobutamine (1311 patients), milrinone (433), or nesiritide (386). MEASUREMENTS AND MAIN RESULTS: Patients with ADHF were categorized according to the vasoactive therapy received. To evaluate baseline characteristics, chi(2) analysis was used; logistic regression was employed to assess the relationships between drug therapy and in-hospital mortality rates, and multivariate linear regression was used to assess whether drug therapy was related to LOS and total health care costs. All regression analyses controlled for age, sex, race, region of the United States where the hospital was located, primary payer for the hospital stay, UHC patient severity class, and chronic renal failure. In-hospital mortality rates were 10.2%, 7.9%, and 2.9% in the dobutamine, milrinone, and nesiritide groups, respectively. This resulted in an adjusted odds ratio for death of 3.5 (95% confidence interval [CI] 1.8-6.8) for dobutamine and 3.9 (95% CI 1.8-8.3) for milrinone (p<0.0001). Compared with inotropic therapy (dobutamine and milrinone), mean LOS in the hospital and the intensive care unit were lower with nesiritide (p<0.001). Total health care costs were lowest with nesiritide, but this reached statistical significance only when compared with milrinone (p<0.001). Thirty-day hospital readmission rates with dobutamine, milrinone, and nesiritide were 5.0%, 9.5%, and 3.9%, respectively (p=NS). CONCLUSION: Nesiritide therapy was associated with a lower in-hospital mortality rate and shorter LOS compared with dobutamine and milrinone. In addition, total health care costs with nesiritide were decreased compared with milrinone. These observations need to be validated by a randomized controlled trial.

Acute Disease↗
PubMed2006

Pharmacotherapy implications of revised chronic heart failure guidelines.

OBJECTIVE: To provide an overview of major drug therapy recommendations within recently revised chronic heart failure (CHF)guidelines. DATA SOURCES: Guideline statements and English-language articles from MEDLINE pertinent to CHF. STUDY SELECTION AND DATA EXTRACTION: Recently published guidelines from the American College of Cardiology (ACC)/American Heart Association (AHA) and the Heart Failure Society of America (HFSA) served as the focus of this review. Prospective comparative trials, review articles, and editorials were also considered. DATA SYNTHESIS: Recommendations within the ACC/AHA and HFSA guidelines continue to provide a systematic, evidence-based approach regarding CHF management. The HFSA guidelines recommend that the severity of clinical disease and functional limitation be characterized using the New York Heart association (NYHA) functional classification system. A key feature of the ACC/AHA guidelines is the use of a staging system that recognizes the development and progression of heart failure. Both guidelines stress the importance of neurohormonal blockade with angiotensin-converting enzyme inhibitors and beta-adrenergic blockers. Moreover, the guidelines expand the role of aldosterone antagonists, angiotensin II receptor blockers, and hydralazine/isosorbide dinitrate, particularly in combination with standard treatments. Diuretics and digoxin remain symptomatic treatments only. CONCLUSIONS: This article summarizes key drug therapy recommendations from the revised ACC/AHA and HFSA guideline statements. Pharmacists caring for CHF patients should be familiar with these recommendations and aid in their implementation.

Adrenergic beta-Antagonists↗
PubMed2005

Family history of coronary heart disease: evidence-based applications.

Clinicians sometimes consider family history of CHD when evaluating CHD risk and deciding whether to prescribe a lipid medication. Most clinicians who take family history of CHD into account do so by categorically adjusting the aggressiveness of patient education and preventive medication recommendations (eg, from a low-key informational mode to a more direct influential or persuasive mode). Quantitative methods exist for taking into account any family history of CHD in parents and siblings, when estimating an individual's 10-year risk for a CHD event; at present, these methods are not readily available. For those individuals who have a positive family history of CHD, using family history-adjusted risk estimates could help clinicians more accurately target high-risk individuals who are the most appropriate candidates for therapeutic lifestyle changes and dyslipidemia drug therapy. Electronic health records (EHR) that now include CHD risk estimation as a decision support feature exclude family history from the calculation. Unless family CHD history is included in EHR decision support modules, family history of CHD will be increasingly discounted or ignored, as clinicians come to rely more and more on computerized decision support aids.

Cholesterol, LDL↗
PubMed2005

Chronic heart failure: developments and perspectives.

OBJECTIVE: To describe the clinical presentation, diagnosis, and contemporary treatment of chronic heart failure (CHF) while emphasizing the important role of the pharmacist. DATA SOURCES: English-language articles from MEDLINE pertinent to CHF. STUDY SELECTION AND DATA EXTRACTION: All relevant publications addressing CHF management were considered, including prospective comparative trials, epidemiological studies, guideline statements, review articles, and editorials. Particular focus occurred on the primary literature published after the release of noted guidelines. The Heart Failure Society of America (HFSA), and the European Society of Cardiology (ESC). DATA SYNTHESIS: Heart failure is a common disorder, especially in the elderly. To determine appropriate pharmacotherapy, one must establish the type of dysfunction (systolic versus diastolic) as well as characterize the patient's disease state according to the New York Heart Association (NYHA) functional classification system and from the American College of Cardiology (ACC)/American Heart Association (AHA), stage of diseases. Although most patients have systolic dysfunction ([ejection fraction] less than 40%), the prevalence of diastolic dysfunction (a normal to elevated ejection fraction) is rising and it accounts for at least one-third of all cases. Six drugs/drug classes are contemporary treatments in systolic heart failure, depending on NYHA functional class: angiotensin-converting-enzyme inhibitors, diuretics, beta-blockers, aldosterone antagonists, angiotensin II receptor-blockers, and digoxin. Clinicians should be aware that studies demonstrate all these drugs/drug classes prolong survival in systolic heart failure, except diuretics and digoxin. Some patients with systolic dysfunction also may be candidates for the combination of hydralazine/isosorbide dinitrate as well as nonpharmacological approaches with biventricular pacemakers and/or implantable cardioverter defibrillators. Treatment of diastolic heart failure is less evidence-based, and speculative treatments focus on control of blood pressure, tachycardia, volume overload, and myocardial ischemia. CONCLUSIONS: CHF treatment remains a therapeutic challenge. Pharmacists have an essential role in the care of these patients by avoiding drugs known to exacerbate the disease, promoting optimal pharmacotherapy, and ensuring compliance with prescribed drugs and dietary modifications.

Journal Article↗
PubMed2004

Phase IV trial evaluating the effectiveness and safety of dofetilide.

BACKGROUND: Dofetilide gained Food and Drug Administration approval for persistent atrial fibrillation/flutter (AFF) based on 2 randomized, placebo-controlled, dose-ranging studies. Concerns of proarrhythmia have prompted the manufacturer to develop specific treatment guidelines. OBJECTIVE: To determine the effectiveness and safety of dofetilide in clinical practice as well as to ascertain whether clinicians are following established dosing guidelines. METHODS: This retrospective analysis evaluated guideline adherence and safety in patients who received dofetilide at a tertiary care medical center. Safety assessment included monitoring for the occurrence of excessive QTc interval prolongation and torsade de pointes. Excessive QTc interval prolongation was defined as >15% above baseline after the first dose or >500 msec following any dose (>550 msec in patients with ventricular conduction abnormalities). Patients were included in the effectiveness assessment if they received at least 36 hours of dofetilide for persistent AFF, received an appropriate dose per guidelines, and did not receive direct current cardioversion during the evaluation period. We compared the 36-hour conversion rate with dofetilide in this study with that observed in the EMERALD and SAFIRE-D trials using the Z test, and we evaluated the incidence of excessive QTc interval prolongation in high-risk subgroups by chi(2) analysis. RESULTS: Investigators identified 107 patients. The primary indication for dofetilide was AFF, with 58.9% receiving the drug for paroxysmal disease. Prescribing followed established guidelines, except that it was used intermittently by nonconfirmed prescribers (5.6%) and/or at inconsistent doses (14%). Excessive prolongation of the QTc interval occurred in 17.8% of patients after the first dose and 26.2% during subsequent doses; prolongation was more common in those with structural heart disease (p < 0.01). No patients developed torsade de pointes. In the effectiveness assessment (n = 25), the conversion of persistent AFF at 36 hours was higher than in previous studies (48% vs 27.2%; p = 0.05). CONCLUSIONS: In clinical practice, the conversion of persistent AFF with dofetilide is at least comparable to premarketing studies, with a similar safety profile. Institutions should continue to emphasize adherence with established treatment guidelines.

Adult↗
PubMed2003

Glycoprotein IIb/IIIa receptor inhibitors in percutaneous coronary intervention and acute coronary syndrome.

OBJECTIVE: To review the contemporary role of the glycoprotein (GYP) IIb/IIIa receptor inhibitors abciximab, eptifibatide, and tirofiban in patients undergoing percutaneous coronary intervention (PCI) and those with an acute coronary syndrome (ACS), and to provide an algorithm based on currently available evidence for specific agents. DATA SOURCES: Primary articles were identified by a MEDLINE search (1966-January 2003); references cited in these articles provided additional resources. STUDY SELECTION AND DATA EXTRACTION: All of the articles identified from data sources were considered for relevant information; this article primarily addresses large, controlled or comparative studies, and meta-analyses. DATA SYNTHESIS: The role of GYP IIb/IIIa inhibitors in patients undergoing PCI and those with ACS has progressed markedly. To date, abciximab has the most robust data in patients undergoing PCI, particularly high-risk individuals. In PCI patients with lower risk (e.g., elective stenting), eptifibatide is a reasonable first-line option. Data do not support tirofiban for routine use in patients undergoing PCI. For individuals with signs and symptoms of ACS, specifically unstable angina or non-ST-segment elevation myocardial infarction (MI), eptifibatide or tirofiban is recommended in high-risk patients when a conservative approach is used (PCI is not planned). Abciximab is not recommended in this situation. In patients with ST-segment elevation MI (STEMI), abciximab is the only GYP IIb/IIIa inhibitor evaluated in large, well-designed investigations. For medical management in combination with a fibrinolytic agent, the role of abciximab remains unclear. For patients undergoing primary PCI for the management of STEMI, the available evidence supports the use of abciximab, albeit further investigation is warranted. CONCLUSIONS: The role of GYP IIb/IIIa inhibitors in clinical cardiology continues to evolve. Choice of the agent depends on situation of use, patient-specific characteristics and risk stratification, and, in the case of ACS, chosen management strategy (medical management or intervention).

Animals↗
PubMed2003

Clinical relevance and management of drug-related QT interval prolongation.

Much attention recently has focused on drugs that prolong the QT interval, potentially leading to fatal cardiac dysrhythmias (e.g., torsade de pointes). We provide a detailed review of the published evidence that supports or does not support an association between drugs and their risk of QT prolongation. The mechanism of drug-induced QT prolongation is reviewed briefly, followed by an extensive evaluation of drugs associated with QT prolongation, torsade de pointes, or both. Drugs associated with QT prolongation are identified as having definite, probable, or proposed associations. The role of the clinician in the prevention and management of QT prolongation, drug-drug interactions that may occur with agents known to affect the QT interval, and the impact of this adverse effect on the regulatory process are addressed.

Drug Approval↗
PubMed2003

Family-oriented cardiac risk estimator: a Java web-based applet.

We developed a Java applet that calculates four different estimates of a person's 10-year risk for heart attack: (1) Estimate based on Framingham equation (2) Framingham equation estimate modified by C-reactive protein (CRP) level (3) Framingham estimate modified by family history of heart disease in parents or siblings (4) Framingham estimate modified by both CRP and family heart disease history. This web-based, family-oriented cardiac risk estimator uniquely considers family history and CRP while estimating risk.

C-Reactive Protein↗