Recent advances in the management of chronic stable angina II. Anti-ischemic therapy, options for refractory angina, risk factor reduction, and revascularization

Abstract

The objectives in treating angina are relief of pain and prevention of disease progression through risk reduction. Mechanisms, indications, clinical forms, doses, and side effects of the traditional antianginal agents – nitrates, β-blockers, and calcium channel blockers – are reviewed. A number of patients have contraindications or remain unrelieved from anginal discomfort with these drugs. Among newer alternatives, ranolazine, recently approved in the United States, indirectly prevents the intracellular calcium overload involved in cardiac ischemia and is a welcome addition to available treatments. None, however, are disease-modifying agents. Two options for refractory angina, enhanced external counterpulsation and spinal cord stimulation (SCS), are presented in detail. They are both well-studied and are effective means of treating at least some patients with this perplexing form of angina. Traditional modifiable risk factors for coronary artery disease (CAD) – smoking, hypertension, dyslipidemia, diabetes, and obesity – account for most of the population-attributable risk. Individual therapy of high-risk patients differs from population-wide efforts to prevent risk factors from appearing or reducing their severity, in order to lower the national burden of disease. Current American College of Cardiology/American Heart Association guidelines to lower risk in patients with chronic angina are reviewed. The Clinical Outcomes Utilizing Revascularization and Aggressive Drug Evaluation (COURAGE) trial showed that in patients with stable angina, optimal medical therapy alone and percutaneous coronary intervention (PCI) with medical therapy were equal in preventing myocardial infarction and death. The integration of COURAGE results into current practice is discussed. For patients who are unstable, with very high risk, with left main coronary artery lesions, in whom medical therapy fails, and in those with acute coronary syndromes, PCI is indicated. Asymptomatic patients with CAD and those with stable angina may defer intervention without additional risk to see if they will improve on optimum medical therapy. For many patients, coronary artery bypass surgery offers the best opportunity for relieving angina, reducing the need for additional revascularization procedures and improving survival. Optimal medical therapy, percutaneous coronary intervention, and surgery are not competing therapies, but are complementary and form a continuum, each filling an important evidence-based need in modern comprehensive management.

Nitrates as an Integral Part of Optimal Medical Therapy and Cardiac Rehabilitation for Stable Angina: Review of Current Concepts and Therapeutics

“…31 Nitrates are an important component of OMT and complement or supplement other antianginal agents. 32 The antianginal effects of nitroglycerin have been known since 1879.…”

Optimal treatment of chronic angina in patients with type 2 diabetes mellitus

“…Eating a "healthy diet": adhering to four of five important dietary components: 94 • low sodium intake ,1.5 g/day;…”

Antagonist molecules in the treatment of angina

“…Coronary auto regulation is a complex phenomenon with many regulating variables, and detailed discussion is beyond the scope of this review [7]. Clinically, angina may be further subdivided according to common usage [8], as follows:…”

“…produce direct, endothelium-independent vasodilatation and reduce myocardial ischemia by relaxation of venous smooth muscle, which lowers ventricular preload and oxygen demand [8]. Short-acting nitrates provide effective symptomatic relief and can be used as prophylaxis before physical exertion that might induce angina [27].…”