Pharmacotherapy: Xanthine oxidase inhibition for relief of angina pectoris

The Role of Ivabradine in the Management of Angina Pectoris

Stable angina pectoris affects 2–4 % of the population in Western countries and entails an annual risk of death and nonfatal myocardial infarction of 1–2 % and 3 %, respectively. Heart rate (HR) is linearly related to myocardial oxygen consumption and coronary blood flow, both at rest and during stress. HR reduction is a key target for the prevention of ischemia/angina and is an important mechanism of action of drugs which are recommended as first line therapy for the treatment of angina in clinical guidelines. However, many patients are often unable to tolerate the doses of beta blocker or non-dihydropyridine calcium antagonists required to achieve the desired symptom control. The selective pacemaker current inhibitor ivabradine was developed as a drug for the management of patients with angina pectoris, through its ability to reduce HR specifically. The available data suggest that ivabradine is a well-tolerated and effective anti-anginal agent and it is recommended as a second-line agent for relief of angina in guidelines. However, recent clinical trials of ivabradine have failed to show prognostic benefit and have raised potential concerns about safety. This article will review the available evidence base for the current role of ivabradine in the management of patients with symptomatic angina pectoris in the context of stable coronary artery disease.

Angina treatments and prevention of cardiac events: an appraisal of the evidence

Angina pectoris is the symptomatic manifestation of transient myocardial ischaemia. At the most fundamental level, angina arises when myocardial oxygen demand exceeds the ability of the coronary circulation to provide adequate oxygen delivery to maintain normal myocardial metabolic function. In vivo, the balance of oxygen demand and delivery is a complex physiological process that can be altered by a variety of interventions. Lifestyle modification is a cornerstone of cardiovascular disease management, with or without angina. Additional pharmaceutical and physical interventions are usually applied to patients with angina. Mechanisms of action for these interventions include heart rate modulation, vascular smooth muscle relaxation, metabolic manipulation, revascularization, and others. A number of these interventions have overlapping mechanisms that target angina. Additionally, some interventions may directly or indirectly prevent or delay adverse outcomes such as myocardial infarction or death. This review summarizes current evidence for many applied ischaemia treatments documented to modify angina and comments on available evidence relating to improvement in cardiovascular outcomes.