Effect of extended-release isosorbide mononitrate one hour after dosing in patients with stable angina pectoris. IMDUR Study Group

Antianginal Therapy for Stable Ischemic Heart Disease

Chronic angina pectoris is associated with considerable morbidity and mortality, especially if treated suboptimally. For many patients, aggressive pharmacologic intervention is necessary in order to alleviate anginal symptoms. The optimal treatment of stable ischemic heart disease (SIHD) should be the prevention of angina and ischemia, with the goal of maximizing both quality and quantity of life. In addition to effective risk factor modification with lifestyle changes, intensive pharmacologic secondary prevention is the therapeutic cornerstone in managing patients with SIHD. Current guidelines recommend a multifaceted therapeutic approach with β-blockers as first-line treatment. Another important pharmacologic intervention for managing SIHD is nitrates. Nitrates can provide both relief of acute angina and can be used prophylactically before exposure to known triggers of myocardial ischemia to prevent angina. Additional therapeutic options include calcium channel blockers and ranolazine, an inhibitor of the late inward sodium current, that can be used alone or in addition to nitrates or β-blockers when these agents fail to alleviate symptoms. Ranolazine appears to be particularly effective for patients with microvascular angina and endothelial dysfunction. In addition, certain antianginal therapies are approved in Europe and have been shown to improve symptoms, including ivabradine, nicorandil, and trimetazidine; however, these have yet to be approved in the United States. Ultimately, there are several different medications available to the physician for managing the patient with SIHD having chronic angina, when either used alone or in combination. The purpose of this review is to highlight the most important therapeutic approaches to optimizing contemporary treatment in response to individual patient needs.

Effect of acute testosterone on myocardial ischemia in men with coronary artery disease

The effect of acute testosterone administration on exercise-induced myocardial ischemia was assessed in 14 men with coronary artery disease and low plasma testosterone concentrations in a study of randomized, double-blind, crossover design. Testosterone increased time to 1-mm ST-segment depression compared with placebo by 66 (15 to 117) seconds (p = 0.016), suggesting a beneficial effect of testosterone on myocardial ischemia in these patients.

Isosorbide 5-mononitrate: a review of a sustained-release formulation (Imdur) in stable angina pectoris

Imdur (IMD) is a sustained-release isosorbide 5-mononitrate preparation for the treatment of chronic stable angina pectoris. Controlled medication release is achieved using the Durules principle of insoluble matrix embedding. Data from randomised double-blind trials show that IMD 60 mg once daily (the most widely studied dosage) has significant antianginal and anti-ischaemic effects compared with placebo after 2 weeks' treatment. Efficacy was generally observed approximately 1 to 12 hours after administration, indicating that once-daily administration in the morning will provide effective prophylaxis of symptoms throughout the day. Improvements from baseline are generally maintained during IMD repeated treatment. There was no evidence of classical tolerance to IMD 30 to 240 mg/day in a large well designed study. Although improvements from baseline were maintained over 6 weeks with IMD 30 or 60 mg/day, statistical significance versus placebo was eventually lost because of improved performance in the placebo group. IMD 120 or 240 mg/day were more effective than placebo after 6 weeks. Studies lasting up to 2 weeks found no evidence of tolerance to IMD 60 mg/day. In comparative trials lasting approximately 2 weeks, IMD 60 mg once daily was more effective than isosorbide dinitrate 30 mg 4 times daily and similar to or better than isosorbide dinitrate 20 mg 3 times daily. Preliminary data show that IMD 60 mg once daily has similar efficacy to diltiazem 60 mg 3 times daily and is at least as effective as certain other sustained-release isosorbide 5-mononitrate preparations. There is no evidence for rebound worsening of ischaemia 24 hours after IMD administration. Abrupt discontinuation during long term IMD treatment may exacerbate anginal symptoms. In general, IMD is well tolerated. The most frequently reported adverse event, headache, is usually mild to moderate, improves with long term therapy and rarely leads to treatment withdrawal. Patient compliance is better with once-daily administration of IMD than with twice-daily administration of conventional isosorbide 5-mononitrate.

CONCLUSIONS

In patients with chronic stable angina, IMD provides effective antianginal prophylaxis for up to 12 hours and does not seem to be associated with rebound phenomena at the end of the dosage interval. Improvements from baseline are maintained during repeated administration, although loss of statistically significant superiority over placebo was evident during 6 weeks' treatment with IMD < or =60 mg/day in 1 study. Further evaluation of comparative efficacy (particularly with respect to other sustained-release preparations) and long term effects would be beneficial. Nevertheless, the available data suggest that IMD is a useful and convenient agent for the treatment of patients with chronic stable angina pectoris.