Cardiovascular

Following the voluntary withdrawal of rofecoxib in September 2004 and the subsequent FDA-requested withdrawal of valdecoxib in April 2005, formulary decision-makers are considering options in navigating the changing pain management landscape. With one remaining COX-2 inhibitor available on the market (celecoxib [Celebrex, Pfizer]) and more cardiovascular (CV) risk data available for the class, the efficacy, adverse events, risk/benefit profiles, and costs of both COX-2-selective and nonselective NSAIDs are receiving more attention than ever.

Analyses of 3 retrospective databases found that warfarin is much less effective at preventing strokes in the real world in patients with chronic atrial fibrillation (AF) than it is in clinical trials. The retrospective data were reported at the ASA's International Stroke Conference 2005.

Clopidogrel reduces 28-day mortality in the treatment of patients with acute myocardial infarction (MI) when given on top of standard therapies, but metoprolol has no effect on in-hospital mortality when given during the acute phase of MI.

The American Heart Association (AHA) Scientific Sessions comprise the largest meeting of its kind held in the cardiovascular field, with several thousand presentations given each year. The recently concluded 2004 AHA Scientific Sessions, which took place in New Orleans, included presentations of trials that evaluated potential therapeutic compounds, as well as widely used and accepted compounds in new dosages or combinations, for the treatment of cardiovascular disorders. The compilation of clinical news that follows focuses on the cardiovascular pharmacotherapy trials of greatest interest to formulary decision-makers, including: CREATE, PEACE, A-HeFT, PROTECT, CLEAR Platelets, DIPOM, GEMINI, SHIELD, and RIO-NA.

A review of select agents in late-stage development for the treatment of arrhythmia, congestive/chronic heart failure, and pulmonary hypertension (PDF) (January 2005)

Researchers conducted a study to determine if self-reported sleep deprivation is associated with an increased risk of coronary events.

Valdecoxib meta-analysis finds increased cardiovascular risk

Nebivolol is a beta-blocker under FDA review for the treatment of hypertension. Nebivolol has unique pharmacologic properties, including high specificity for the beta-1 receptor and a nitric oxide-mediated vasodilatory effect. The agent provides significant blood pressure reduction from baseline values and as compared to placebo. Clinical trials have demonstrated that nebivolol reduces blood pressure similarly to atenolol, bisoprolol, amlodipine, nifedipine, lisinopril, and hydrochlorothiazide. The tolerability of nebivolol is similar to or better than that of these agents. If approved, nebivolol would likely be a viable alternative therapy for hypertension; however, additional studies are needed in patients with heart failure and coronary artery disease.

Rofecoxib voluntarily withdrawn from market due to cardiovascular risk

Initiating high-dose simvastatin (Zocor, Merck) early after an acute coronary syndrome (ACS) event does not result in significantly superior clinical outcomes compared to delayed initiation of low-dose simvastatin.This major finding of phase Z of the A to Z Trial is in contrast to the results of 2 previous clinical trials in which aggressive therapy with atorvastatin (Lipitor, Pfizer) was found to be superior to less aggressive statin therapy in reducing the risk of adverse clinical events in ACS patients.

The Warfarin/Aspirin Study in Heart Failure provided no evidence that aspirin is effective or safe in heart failure patients.

A study presented on August 25 at the 20th International Conference on Pharmacoepidemiology & Therapeutic Risk Management in Bordeaux, France, revealed that higher-dose rofecoxib (>25 mg/d) was associated with a greater risk of acute myocardial infarction (AMI) and sudden cardiac death (SCD) compared to other NSAIDs. The risk of AMI and SCD was also increased with lower-dose rofecoxib (25 mg/d) when compared with celecoxib. The maximum recommended daily doses of rofecoxib in the management of pain associated with osteoarthritis, rheumatoid arthritis, primary dysmenorrhea, and migraine attacks with or without aura are 25, 25, 50, and 50 mg/d, respectively.

A study presented on August 25 at the 20th International Conference on Pharmacoepidemiology & Therapeutic Risk Management in Bordeaux, France, revealed that higher-dose rofecoxib (>25 mg/d) was associated with a greater risk of acute myocardial infarction (AMI) and sudden cardiac death (SCD) compared to other NSAIDs. The risk of AMI and SCD was also increased with lower-dose rofecoxib (25 mg/d) when compared with celecoxib. The maximum recommended daily doses of rofecoxib in the management of pain associated with osteoarthritis, rheumatoid arthritis, primary dysmenorrhea, and migraine attacks with or without aura are 25, 25, 50, and 50 mg/d, respectively.

Current treatment options for acute coronary syndromes as well as chronic stable angina often include the use of percutaneous coronary intervention (PCI) with routine stenting. The clear benefits of stents have lead to their routine use for prevention of restenosis. However, the benefits of stenting demonstrated on some aspects of restenosis are compromised by the induction of restenosis by neointimal hyperplasia that is stimulated by standard bare metal stents. FDA has approved 2 drug-eluting stents (DES). DES create a local delivery system at the vascular site to reduce restenosis by neointimal hyperplasia. Multiple clinical trials have demonstrated the safety and efficacy of the use of DES. This article reviews the use of PCI in coronary artery disease, the evolution and pathophysiology of restenosis, and multiple aspects of DES technology. While DES may not be a direct pharmacy and therapeutics committee responsibility, committee members are being called upon to provide insights into pathway processes for medical technology review committees evaluating DES since these products contain a key pharmacologic component. There are also important adjunctive antiplatelet therapy protocols that need to be developed and adhered to in conjunction with DES in order to ensure optimal outcomes.

A newly released update to the National Cholesterol Education Program's (NCEP) guidelines on cholesterol management recommend that clinicians consider more intensive treatment options for patients at high and moderately high risk for heart attack. These evidence-based recommendations include setting lower treatment goals for low-density lipoprotein cholesterol (LDL-C) and initiating cholesterol-lowering drug therapy at lower LDL thresholds.

A study was conducted to assess hospital admission rates for congestive heart failure in patients dispensed cyclooxygenase-2 (COX-2) inhibitors or nonselective nonsteroidal anti-inflammatory drugs (NSAIDs). Researchers at the Institute for Clinical Evaluative Sciences in Toronto, Ontario, Canada, studied patients taking rofecoxib (Vioxx, Merck), celecoxib (Celebrex, Pfizer), and nonselective NSAIDs, with a control group consisting of non-NSAID users who were not given any study drugs. Study findings indicate that, relative to non-NSAID users, patients receiving rofecoxib and nonselective NSAIDs had an increased risk of admission for congestive heart failure than patients taking celecoxib.

Findings from a newly released Women's Health Initiative (WHI) study suggest that conjugated equine estrogen (CEE) alone should not be used for chronic disease prevention, specifically coronary heart disease (CHD), in postmenopausal women. The study, published in the Journal of the American Medical Association, found that CEE increased the risk of stroke by 39% and offered no protection against heart disease.

Combination use of clopidogrel and aspirin the night before undergoing carotid endarterectomy (CEA) may significantly reduce the risk of cerebral emboli, according to a study published in the journal Circulation.

Adjusted-dose warfarin compared to aspirin more effectively reduces the high risk of secondary stroke in atrial fibrillation (AF) patients who have a history of transient ischemic attack (TIA), according to a study published in the journal Stroke.

In phase 3 trials, the first agent in a novel class known as the selective cannabinoid type 1 receptor blockers doubled the odds of quitting smoking while reducing post-cessation weight gain compared with placebo. The agent, rimonabant, also improved several features of the metabolic syndrome in patients with abdominal obesity, reported researchers at the 53rd Annual Scientific Session of the American College of Cardiology (ACC).

>Enoxaparin is an effective and safe alternative to unfractionated heparin (UFH) in the early and invasive management of high-risk patients with non-ST-elevation acute coronary syndromes (ACS), said Robert Califf, MD, at the 53rd Annual Scientific Session of the American College of Cardiology (ACC).

The clinical benefit of aspirin on first myocardial infarction diminishes with regular-but not intermittent-use of nonsteroidal anti-inflammatory drugs, according to a study published in the journal Circulation.

The American Heart Association (AHA) Scientific Sessions comprise the largest meeting of its kind held in the cardiovascular field, with several thousand presentations given each year. The recently concluded 2003 AHA Scientific Sessions included presentations of trials that evaluated potential therapeutic compounds, as well as widely used and accepted compounds in new dosages or combinations, for the treatment of cardiovascular disorders. The compilation of clinical news reviewed focuses on the cardiovascular pharmacotherapy trials of greatest interest to formulary decision-makers, including: VALIANT, REVERSAL, SPORTIF V, PAPABEAR, PRIMO-CABG, and CREST.

Users of statins were 20% less likely to have cancer (adjusted odds ratio, 0.80; 95% CI, 0.66­0.96) in a case-control study from the Academic Medical Centre, University of Amsterdam, Netherlands, that was presented at the 39th Annual Meeting of the American Society of Clinical Oncology

Three different drugs at half the standard dose are estimated to reduce the risk of stroke by 63% and ischemic heart disease (IHD) events by 46% for those aged 60 to 69 years, according to a study in BMJ. Another study published in the same issue recommends that those with known occlusive vascular disease and everyone aged 55 years or older take a "polypill," including the combination of blood pressure-lowering drugs, a statin, folic acid, and aspirin.

Current medical therapy for chronic stable angina (CSA) is targeted at reducing the frequency of anginal symptoms and improving exercise tolerance by increasing myocardial oxygen supply and/or reducing myocardial oxygen demand. Pharmacological therapy for CSA is limited since traditional agents provide pain relief by reducing the work of the heart or dilating arterioles in an attempt to enhance supply. Combinations of these agents can induce profound reductions in blood pressure that limit the aggressive dosing needed in some patients. Metabolic modulators seek to overcome this issue through a novel mechanism of action. Ranolazine (Renexa, CV Therapeutics) is a partial fatty oxidase (pFOX) inhibitor that increases the amount of ATP produced from glucose and increases the ability of the myocardium to retain functionality despite a reduced oxygen supply. (Formulary 2003;38:461?476)

Patients with diabetes are at extremely high risk for cardiovascular disease. Because glucose control is associated with only modest reductions in macrovascular complications, efforts must be made to specifically target other cardiovascular risk factors. Diabetes is associated with a characteristic lipid profile: low high-density lipoprotein cholesterol (HDL-C) and high triglyceride levels with or without high low-density lipoprotein cholesterol (LDL-C) levels. This profile is also found in patients with early-onset coronary heart disease and correlates with increased atherogenesis. Multiple clinical trials have demonstrated that lipid-modifying therapy in patients with diabetes decreases cardiovascular risk. Management targeting all lipid abnormalities may represent the best treatment strategy since many patients with diabetes do not have elevated LDL-C levels. Combining lipid-modifying agents is also an attractive option for normalizing multiple lipid abnormalities. (Formulary 2003;38:478-497)

The utility of doxorubicin is limited by the risk of cumulative, dose-related, progressive myocardial damage.

Pulmonary arterial hypertension (PAH) is a progressive, debilitating disorder associated with poor quality of life and shortened life span. For many years, medical therapy consisted of calcium channel blockers, warfarin, supplemental oxygen, and digitalis glycosides. A better understanding of the pathophysiology of PAH has led to the recent development of effective treatments for this disorder. Therapeutic agents target the pathophysiologic mechanisms of PAH: pulmonary vasoconstriction, pulmonary vascular remodeling, and in situ thrombosis. With better understanding of the pathogenesis of PAH, recent advances in pharmacotherapy have been introduced for the treatment of PAH. Data are presented on efficacy and safety of newer approved and investigational agents: prostacyclin analogues, oral endothelin antagonists, and phosphodiesterase 5 inhibitors.

Ezetimibe (Zetia), approved in late October, represents the first new class of cholesterol-lowering drugs in 15 years. Ezetimibe, an intestinal cholesterol absorption inhibitor, has a unique mechanism of action, distinct from those of statins and bile acid sequestrants. When used as monotherapy, ezetimibe lowers low-density lipoprotein cholesterol (LDL-C) levels up to 18.5%. Coadministration of ezetimibe with statin therapy reduces LDL-C levels up to an additional 22%. The article reviews ezetimibe?s chemistry, pharmacology, pharmacokinetics, and clinical trial results.