Nifedipine gastrointestinal therapeutic system versus atenolol in stable angina pectoris. The Netherlands Working Group on Cardiovascular Research (WCN)

Beta-Blockers, Calcium Channel Blockers, and Mortality in Stable Coronary Artery Disease

PURPOSE OF REVIEW

To examine the current clinical evidence behind the use of calcium channel blockers (CCB) and beta-blockers (BB) for the treatment of patients with stable coronary artery disease (SCAD) and their effect on mortality.

RECENT FINDINGS

Current evidence suggests that BB use as a first line antianginal medication is associated with lower 5-year all-cause mortality only in patients who had MI within a year. This could be driven due to their effects reducing the sympathetic neuro-hormonal activation of more acutely ill patients. The use of CCB as an antianginal therapy, although proven effective in multiple trials both as monotherapy and combined with other agents, has not shown mortality benefit. Both BB and CCB are effective antianginals, and the selection among them depends on the patient clinical presentation and comorbidities. BB are the only ones that have shown survival benefit in SCAD, particularly the first year post-MI.

Management of Angina Post Percutaneous Coronary Intervention

PURPOSE OF REVIEW

Our review discusses the management of post percutaneous coronary intervention angina (PPCIA) which negatively impacts 20-40% of patients and imposes a high burden on the healthcare system.

RECENT FINDINGS

Mechanisms of PPCIA include microvascular dysfunction, distal coronary vasospasm or disease, microembolization, myocardial bridge, coronary artery disease (CAD) progression, and rarely stent thrombosis or in-stent restenosis. Nitrates, beta blockers (BB), calcium channel blockers, and ranolazine are the common medical management options. Only BB showed 1-year mortality benefit following myocardial infarction. Stress echocardiography and cardiac magnetic resonance are the best to detect CAD vs. microvascular dysfunction. Invasively, vasoprovocative testing and fractional flow reserve provide useful prognostic information. If the ischemia burden is ≤10%, conservative management should be considered based upon the individual patient scenario. The optimal management of PPCIA remains unclear and further research is necessary. Multiple treatment options exist, which should be implemented in an individualized fashion.

The Real Role of β-Blockers in Daily Cardiovascular Therapy

The role of β-adrenoceptor antagonists (β-blockers) in cardiovascular therapy has been subject to diverse trends and changes over the decades. With the advent of a wide variety of excellent drugs for the treatment of antihypertension, β-blockers have been relegated from the first-line treatment of essential hypertension. However, they remain the drugs of first choice in recommendations from the respective medical societies for heart failure, coronary artery disease, and atrial fibrillation as well as in hypertension complicated with heart failure, angina pectoris, or prior myocardial infarction. When indicated, cardioselective β-blockers should be prescribed in patients with diabetes mellitus or chronic obstructive pulmonary disease. We review the available evidence for the use of β-blockers in clinical conditions in which recommendations can be made for everyday practice.

Management standards for stable coronary artery disease in India

Coronary artery disease (CAD) is one of the important causes of cardiovascular morbidity and mortality globally, giving rise to more than 7 million deaths annually. An increasing burden of CAD in India is a major cause of concern with angina being the leading manifestation. Stable coronary artery disease (SCAD) is characterised by episodes of transient central chest pain (angina pectoris), often triggered by exercise, emotion or other forms of stress, generally triggered by a reversible mismatch between myocardial oxygen demand and supply resulting in myocardial ischemia or hypoxia. A stabilised, frequently asymptomatic phase following an acute coronary syndrome (ACS) is also classified as SCAD. This definition of SCAD also encompasses vasospastic and microvascular angina under the common umbrella.

Efficacy of β-blocker therapy for secondary prevention for patients undergoing coronary artery bypass grafting surgery

PURPOSE OF REVIEW

The efficacy and safety of β-blockers in the treatment of cardiovascular diseases, such as ischemic heart disease, cardiac arrhythmias, and heart failure, have been well established for decades. In this article, we review the current opinions on the application of β-blockers for secondary prevention in patients undergoing coronary artery bypass grafting (CABG) surgery.

RECENT FINDINGS

As the average age of patients treated surgically for coronary artery disease (CAD) is increasing, it is not uncommon to have candidates for CABG presenting with concomitant atrial fibrillation, heart failure or hypertension, most of which were caused by excessive activation of the adrenergic nervous system. In a recent decade, a number of national quality-improvement efforts using a variety of techniques have been made to increase the use of β-blocker therapy before or following the CABG. Results from recent large observational studies among patients with CAD showed that β-blockers were associated with a lower risk of cardiac events only among those with heart failure or recent myocardial infarction. However, the consistent use of β-blockers could benefit those with or without prior myocardial infarction who underwent CABG and discharged alive.

SUMMARY

In real-world clinical practice, β-blockers are effective and safe to control heart rate and symptoms in patients with CAD, especially for those concomitant with left ventricular systolic dysfunction or prior myocardial infarction. Current evidence supports the preoperative use of β-blocker therapy for patients undergoing CABG as a prevention of new-onset atrial fibrillation. It is reasonable to continue β-blockers as chronic therapy in all CABG patients without contraindications after hospital discharge. Further strategies should be developed to understand and improve discharge prescription of β-blockers and long-term patient adherence.

Nifedipine gastrointestinal therapeutic system (GITS) in the treatment of coronary heart disease and hypertension

Since the 1960s, calcium antagonists have been available for the treatment of angina pectoris and hypertension. The first of this class, nifedipine, was introduced and readily accepted as the third treatment option for angina, alongside beta-blockers and nitrates. However, the short-acting formulations of nifedipine had pharmacokinetic properties that were far from ideal and in 1995, several studies involving various dosing regimens reported possible dangerous effects in secondary prevention. Since then, large-scale, randomized controlled trials with new controlled-released formulations of nifedipine have demonstrated the effectiveness and safety of this drug. As a consequence of these results, guidelines for both hypertension and angina pectoris have been recently reconsidered, and have put the modern formulations of calcium channel blockers in a pole position. Within this group of therapeutics, nifedipine gastrointestinal therapeutic system has a unique position and it cannot be replaced by other controlled-release formulations of nifedipine, the pharmaceutical properties of which have yet to be tested in large-scale outcome trials.

Long-term beta blockers for stable angina: systematic review and meta-analysis

Objectives: To assess the effects of long-term beta blockers in patients with stable angina.

Methods: We reviewed the literature up to June 2010 from CENTRAL, MEDLINE, EMBASE, CBM, and CNKI for randomized controlled trials. The appropriate data were meta-analysed using Revman 5.0.

Results: Twenty-six trials including 6108 patients were identified. The treatment with beta blockers has significantly decreased all-cause mortality when compared with no control (OR 0.40, 95% CI 0.20 to 0.79), but has had no statistically differences when compared with placebo (OR 0.92, 95% CI 0.62 to 1.38) and with calcium-channel blocker (CCB) (OR 0.84, 95% CI 0.49 to 1.44). This was similar in patients with fatal and non-fatal acute myocardial infarction when compared with placebo (OR 0.82, 95% CI 0.57 to 1.17) or CCB (OR 1.08, 95% CI 0.71 to 1.66); on revascularization and quality of life. The beta blockers reduced the incident of unstable angina compared to no treatment (OR 0.14, 95% CI 0.07 to 0.29), but increased unstable angina compared to placebo (OR 3.32, 95% CI 1.50 to 7.36). There was a significant reduction of nitrate consumption when beta blockers were compared with CCBs (OR −1.18, 95% CI −1.54 to −0.82), but not with placebo and trimetazidine. There was no significant difference in angina attack between each group. Side effects in beta blocker were similar with ones in controls.

Conclusions: Beta blockers may decrease the death and unstable angina when compared with no treatment, but no more effective than other anti-anginal agents on prophylaxis of myocardial ischaemia in stable angina patients.

Modified-release nifedipine: a review of the use of modified-release formulations in the treatment of hypertension and angina pectoris

Nifedipine is a dihydropyridine calcium channel antagonist with predominantly vasodilatory activity. Modified-release formulations of nifedipine are effective antihypertensive and antianginal therapies and are generally well tolerated. Among the available formulations, those that produce a gradual increase in plasma nifedipine concentration, which is then sustained over a 24-hour period, are preferred, as they cause a gradual onset of vasodilatation and avoid baroreflex sympathetic activation (for example, nifedipine gastrointestinal therapeutic system [GITS] and a Japanese controlled-release formulation). Modified-release nifedipine had beneficial effects on a number of markers of vascular function, and nifedipine GITS reduced the need for coronary procedures in patients with coronary artery disease. In patients with hypertension, nifedipine GITS and nifedipine retard had beneficial effects on the overall incidence of major cardiovascular events, as did nifedipine retard in patients with concurrent hypertension and coronary artery disease.

A randomized trial to assess the impact of opinion leader endorsed evidence summaries on the use of secondary prevention strategies in patients with coronary artery disease: the ESP-CAD trial protocol [NCT00175240]

BACKGROUND

Although numerous therapies have been shown to be beneficial in the prevention of myocardial infarction and/or death in patients with coronary disease, these therapies are under-used and this gap contributes to sub-optimal patient outcomes. To increase the uptake of proven efficacious therapies in patients with coronary disease, we designed a multifaceted quality improvement intervention employing patient-specific reminders delivered at the point-of-care, with one-page treatment guidelines endorsed by local opinion leaders ("Local Opinion Leader Statement"). This trial is designed to evaluate the impact of these Local Opinion Leader Statements on the practices of primary care physicians caring for patients with coronary disease. In order to isolate the effects of the messenger (the local opinion leader) from the message, we will also test an identical quality improvement intervention that is not signed by a local opinion leader ("Unsigned Evidence Statement") in this trial.

METHODS

Randomized trial testing three different interventions in patients with coronary disease: (1) usual care versus (2) Local Opinion Leader Statement versus (3) Unsigned Evidence Statement. Patients diagnosed with coronary artery disease after cardiac catheterization (but without acute coronary syndromes) will be randomly allocated to one of the three interventions by cluster randomization (at the level of their primary care physician), if they are not on optimal statin therapy at baseline. The primary outcome is the proportion of patients demonstrating improvement in their statin management in the first six months post-catheterization. Secondary outcomes include examinations of the use of ACE inhibitors, anti-platelet agents, beta-blockers, non-statin lipid lowering drugs, and provision of smoking cessation advice in the first six months post-catheterization in the three treatment arms. Although randomization will be clustered at the level of the primary care physician, the design effect is anticipated to be negligible and the unit of analysis will be the patient.

DISCUSSION

If either the Local Opinion Leader Statement or the Unsigned Evidence Statement improves secondary prevention in patients with coronary disease, they can be easily modified and applied in other communities and for other target conditions.