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In recent years, concern has been expressed over attenuation of therapeutic effect in patients receiving continuous nitroglycerin therapy for the treatment of angina. Studies have shown that exercise tolerance time does not improve with continuous nitroglycerin regimens, although the frequency of anginal attacks may decrease. Intermittent therapy, which incorporates a nitrate-free interval, improves both exercise time and clinical angina. The optimal duration of the nitrate-free interval has yet to be determined. Future research is likely to focus more on supply-side factors in angina. Of the available antianginal drugs, nitrates have been shown to be highly effective coronary vasodilators, particularly in areas of stenosis.

Practicing physicians now have the capability as well as the responsibility to treat hyperlipidemia. Recent conclusive trials have demonstrated the link between lipid elevations and coronary heart disease, as well as the likelihood of reducing coronary heart disease risk by lowering blood lipids via diet and/or drug intervention. Screening criteria for hyperlipidemia in normal patients and in special patient subgroups are described, and recommendations for treatment are proposed. The diet recommended by the American Heart Association--which limits fat intake to 25% to 30% of all calories in a 1:1:1 ratio of saturated, monounsaturated and polyunsaturated fats, and limits cholesterol to less than 300 mg/day--is discussed. Guidelines are suggested for drug therapy with lipid-lowering agents to reduce abnormal lipid levels when diet alone proves insufficient after 2- to 3-month trial.

Advantages and disadvantages of the various therapies for stable angina are considered with particular attention to quality of life. Advantages of coronary artery bypass surgery (CABS), apart from the question of survival, include less angina, less activity limitation, and less need for drugs than with medical treatment. However, data from the Coronary Artery Surgery Study (CASS) and others show that there is no difference between medical and surgical therapy in return to work and in need for subsequent hospitalization. In CABS patients, there is also predictable return of angina, substantial late vein graft occlusion, and possibly increased progression of native coronary artery disease in grafted vessels. Percutaneous transluminal coronary angioplasty (PTCA) has advantages similar to those of CABS, with very low initial mortality and major complication rates, minimal discomfort, very short disability period, and moderate cost. Its major disadvantages are a high short-term reocclusion rate and uncertain long-term outcome. Beta blockers provide good control of angina, have additional antihypertensive and antiarrhythmic effects, and may be beneficial in preventing sudden cardiac (arrhythmic) death and limiting myocardial infarct size, should these events supervene in the patient with angina. Disadvantages of beta blockers involve the occasional major side effects, including potential exacerbation of bronchospasm, peripheral vascular disease (PVD), diabetes, congestive heart failure and bradyarrhythmia, and frequent "nuisance" side effects. Calcium blockers control both exercise and rest angina and pose no problem in patients with bronchoconstriction, PVD, or diabetes. Disadvantages include need for frequent dosage, cost, and side effects. Long-acting nitrates have few major side effects and usually transient minor side effects, with little effect on quality of life.(ABSTRACT TRUNCATED AT 250 WORDS)

If altered platelet function contributes to poorly perfused zones of myocardium in patients with angina pectoris, then specific antiplatelet therapy might improve cardiovascular function and exercise performance. Exercise tolerance on a bicycle ergometer, heart rate-blood pressure product, and ischemic ECG changes at exercise end-point were compared before and during oral aspirin therapy (2.4 Gm. per day for 2 weeks) in 11 normal subjecs and in 11 patients with stable angina pectoris. Platelet aggregation threshold in response to ADP and epinephrine was measured. Untreated patients had increased platelet aggregability when compared to normal subjects...

Nicardipine is a new dihydropyridine calcium channel blocking drug with actions that suggest considerable usefulness as an agent for chronic stable angina. Hemodynamic studies in patients with coronary artery disease confirm major coronary vasodilator actions, perhaps even exceeding its considerable systemic vasodilator properties with little or no negative inotropic effect. Three recent controlled clinical trials that used nicardipine alone suggest approximately 20% to 30% increase in exercise time, and at least that much decrease in anginal episodes and sublingual nitroglycerin consumption when compared with placebo in doses of 90 to 120 mg daily. Five trials comparing nicardipine with other calcium channel blockers, and three with beta blockers, suggest equivalent efficacy, including decrease in angina and increase in exercise time. Adverse effects of nicardipine generally relate to its potent vasodilatory capability and are usually minor. Side effects are frequent at the beginning of many trials, usually do not cause undue withdrawals, and are quite rare after 6 to 12 months on the drug in most studies.