Efficacy of amlodipine besilate therapy for variant angina: evaluation by 24-hour Holter monitoring

Coronary artery spasm: Current knowledge and residual uncertainties

Myocardial ischaemia results from a direct mismatch between oxygen supply and demand, commonly arising as a result of coronary atherosclerosis, microvascular dysfunction or acute thrombosis and luminal obstruction. However, transient ischaemia may also occur due to coronary spasm leading to acute and unexpected myocardial ischaemia without obvious visible coronary pathology. Aside from symptoms of chest pain, coronary spasm can cause infarction, LV impairment, promote life threatening arrhythmias and ultimately sudden cardiac death. While therapeutic options are available, controversies exist around diagnosis, pathology, management and prognosis. This review summarises some of the common questions in this area. In particular we explore and discuss the available evidence for the pharmacological treatment of coronary spasm, and strategies for identification and management of very high risk patients to try and reduce the incidence of sudden premature death.

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Myocardial ischaemia results from a mismatch between oxygen supply and demand.

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Spasm might lead to myocardial ischaemia without visible coronary pathology.

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Coronary spasm can cause infarction, LV impairment and sudden cardiac death.

Abnormal fatty acid metabolism in patients with coronary vasospasm

Although various noninvasive methods have been used to detect vasospasm, none of them are sensitive enough for patients with sporadic attacks. Since abnormal fatty acid metabolism is observed in ischemic myocardium, 123I-beta-methyl-p-iodophenyl pentadecanoic acid (BMIPP), a radiolabeled fatty acid analog, has recently been proposed as a useful tracer for detecting myocardial damage. The aim of this study was to clarify the clinical implications of decreased myocardial BMIPP uptake in patients with vasospastic angina. We evaluated 53 patients with vasospastic angina (32 with clinically documented vasospasm [Group-A] and 21 with vasospasm induced by ergonovine provocation [Group-B]) and 27 control subjects, 20 in Group-A were re-evaluated 6 months after medical treatment. The territorial regions of vasospasm-induced coronary artery, the wall motion by left ventriculography, and BMIPP uptake were compared. Vasospasm was induced in multiple coronary arteries in 29 (55%) patients. Reduced wall motion and decreased BMIPP uptake were observed in 19 (36%) patients and 47 (89%) patients, respectively. The sensitivity and specificity of determination of vasospasm-induced coronary arteries with BMIPP scintigraphy were 71% (69/97 coronary arteries) and 88% (126/143), respectively. Vasospasm was re-induced by ergonovine provocation in 8 patients (Group-I) and not re-induced in 12 (Group-II) after treatment. In Group-I, improvement of decreased BMIPP uptake was lower than in Group-II (19+/-11 vs. 59+/-22%, mean+/-SD, p < 0.001). The regions in which vasospasm was re-provoked exhibited decreased BMIPP uptake. Abnormal fatty acid metabolism was more often observed than wall motion abnormality in the vasospastic region in patients with vasospastic angina. BMIPP scintigraphy is a highly accurate and non-invasive technique for determining the presence and location of vasospasm.

Clinical evaluation of serum amlodipine level in patients with angina pectoris

Serum amlodipine levels were determined in 18 patients with vasospastic angina. Patients were divided into two groups: Group A (n = 9) received amlodipine 5 mg by single daily administration, and Group B (n = 9) received 10 mg given by single daily administration for the first 3 days, then 5 mg from the 4th day on. The serum amlodipine concentration in Group A took 7 days to reach a steady state of around 8 ng/ml. The level in Group B was 8.9 ng/ml at 3 days. From these results, the optimal dosage of amlodipine in the treatment of angina pectoris is 10 mg for the initial 3 days followed by 5 mg thereafter.

Calcium channel antagonists in the management of anginal syndromes: changing concepts in relation to the role of coronary vasospasm

Despite the increasing evidence that alterations in coronary vascular tone can and do occur in patients with anginal syndromes, only in a minority of such patients with Prinzmetal's angina is there decisive evidence that the coronary vasodilation induced by calcium channel antagonists (CCAs) plays a specific therapeutic role. CCAs may also give therapeutic benefit in a number of conditions in which coronary vasoconstriction may contribute to ischemia, such as hyperventilation, cold-induced angina, or silent ischemia not caused by an increase in heart rate. Thus, the decision of whether or not to use CCAs in angina syndromes will often have to be made on grounds other than what appears to be a minor role of vasospasm in the overall spectrum of angina. There are preliminary indications that the long-term prognosis may be different among different categories of CCAs.