Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A large body of evidence suggests that persistently high heart rate may be associated with a significant increase in sudden death, myocardial infarction and total mortality. Such deleterious effects may be mediated via neurohumoral activation. Conversely, interventions, such as beta-blockers, that consistently reduce heart rate may reduce sudden death and prolong survival, especially in patients who survive myocardial infarction. Thus, the deleterious effect of antianginal compounds, which may increase heart rate, is especially important in chronic myocardial syndromes as well as in chronic stable angina. In this setting, the evidence is consistent with the belief that antianginal agents that increase heart rate significantly, irrespective of their other properties, may also increase the incidence of myocardial infarction or death, in contrast to agents that induce little or no tachycardic effect or those that produce frankly bradycardic responses. Data discussed in this paper indicate that long acting calcium channel blockers of the dihydropyridine type do not increase heart rate significantly. Their slower onset and offset of action may reflect a lack of neurohumoral activation, recently confirmed in the case of nifedipine gastrointestinal therapeutic system (GITS). Data from the Nifedipine gastrointestinal therapeutic system Circadian Antiischemic Program (N-CAP) study, summarized herein, confirmed that the GITS formulation produces a minimal increase in heart rate over a period of 24 h. When the compound was given alone or with a beta-blocker, it was highly effective in suppressing symptomatic and asymptomatic episodes of myocardial ischemia in patients with chronic stable angina. These findings have important implications for the treatment of ischemia in patients with chronic stable angina.
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PMID:The relevance of sympathetic activity in the pharmacological treatment of chronic stable angina. 1020 52

Fasting and postglucose hyperinsulinemia are recognized risk factors for acute coronary events. The insulin reactivity of patients with acute coronary syndromes, however, has not been carefully compared with that of patients with chronic stable angina. We used Bergman's minimal model to analyze the insulin response to intravenous glucose in 21 subjects: 8 patients with previous (>3 months) acute coronary syndrome but no effort-related angina; 6 patients with stable effort angina but no prior acute event; and 7 healthy controls. Diabetes mellitus, systemic hypertension, dyslipidemias, and obesity were excluded. All patients underwent coronary angiography. Insulin sensitivity, glucose effectiveness, and glucose tolerance were determined from insulin and glucose concentrations measured frequently up to 3 hours after a 0.33 g/kg intravenous glucose bolus. Patients with previous unstable angina or acute myocardial infarction had less extensive disease at angiography than patients with stable angina (p = 0.007). Both patient groups had higher basal and 180-minute insulinemia than controls (p <0.0007). However, patients with stable angina did not differ significantly from controls with regard to early and late insulinemic response to glucose. In contrast, patients with previous acute onset of ischemia had significantly greater 180-minute integrated insulinemia (p = 0.04) and reduced insulin sensitivity (p = 0.05) after the glucose challenge than did the stable angina group. These data suggest that patients with acute presentation of coronary artery disease, compared with patients with uncomplicated chronic stable angina, have an impaired insulin response to glucose despite less extensive coronary disease at angiography.
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PMID:Comparison of insulin response to intravenous glucose in healed myocardial infarction, in "cooled-off" unstable and stable angina pectoris, and in healthy subjects. 1053 2

The prognostic significance of ambulatory ischemia, alone and in relation to ischemia during exercise was assessed in 686 patients (475 men) with chronic stable angina pectoris taking part in the Angina Prognosis Study In Stockholm (APSIS), who had 24-hour ambulatory electrocardiographic registrations and exercise tests at baseline (n = 678) and after 1 month (n = 607) of double-blind treatment with metoprolol or verapamil. Ambulatory electrocardiograms were analyzed for ventricular premature complexes and ST-segment depression. During a median follow-up of 40 months, 29 patients died of cardiovascular (CV) causes, 27 had a nonfatal myocardial infarction, and 89 underwent revascularization. Patients with CV death had more episodes (median 5 vs. 1; p<0.01) and longer median duration (24 vs. 3 minutes; p<0.01) of ST-segment depression than patients without events. For those who had undergone revascularization, the duration was also longer (12 vs. 3 minutes; p<0.05). In a multivariate Cox model including sex, history of previous myocardial infarction, hypertension, and diabetes, the duration of ST-segment depression independently predicted CV death. When exercise testing was included, ambulatory ischemia carried additional prognostic information only among patients with ST-segment depression > or =2 mm during exercise. When the treatment given and treatment effects on ambulatory ischemia were added to the Cox model, no significant impact on prognosis was found. Ventricular premature complexes carried no prognostic information. Thus, in patients with stable angina pectoris, ischemia during ambulatory monitoring showed independent prognostic importance regarding CV death. Ambulatory electrocardiographic monitoring and exercise testing provide complementary information, but only among patients with marked ischemia during exercise. Treatment reduced ambulatory ischemia, but the short-term treatment effects did not significantly influence prognosis.
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PMID:Prognostic implications of ambulatory myocardial ischemia and arrhythmias and relations to ischemia on exercise in chronic stable angina pectoris (the Angina Prognosis Study in Stockholm [APSIS]). 1056 22

The mechanism by which ischemia stimulates angiogenesis is unknown. Adenosine is released during myocardial ischemia and may be a mediator of this process. Experimental data suggest that heparin may enhance this effect. The purpose of this open-labeled, placebo-controlled trial was to determine whether repeated intravenous administration of adenosine and heparin could mimic physiologic angiogenesis and reduce the amount of exercise-induced myocardial ischemia in patients with coronary artery disease. Subjects with chronic stable angina refractory to conventional medical therapy and not suitable for revascularization received either adenosine (140 microg/kg/min for 6 minutes) and heparin (10,000 U bolus), (n = 14), or placebo, (n = 7) daily for 10 days. All patients underwent baseline and follow-up exercise testing with thallium-201 single-photon emission computed tomography myocardial perfusion imaging. A semiquantitative assessment of the extent and severity of the perfusion abnormalities was calculated by 2 blinded investigators. There was no significant change in exercise duration or in the peak heart rate systolic blood pressure product associated with adenosine and heparin compared with placebo treatment. There was, however, a 9% reduction in the extent (60.6 +/- 4.0 vs 54.9 +/- 4.1, p = 0.03) and a 14% improvement in severity (41.5 +/- 3.2 vs 35.7 +/- 2.9, p = 0.01) of the myocardial perfusion abnormalities seen in patients who received adenosine and heparin compared with placebo. Thus, in this pilot study, repeated administration of adenosine and heparin reduced the amount of exercise-induced ischemia in patients with chronic stable angina refractory to conventional treatment.
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PMID:Effects of the repeated administration of adenosine and heparin on myocardial perfusion in patients with chronic stable angina pectoris. 1107 27

Myocardial ischemia during daily life can be induced by increased demand and by increased coronary tone. The purpose of this study was to assess the mechanism of action of mibefradil, a new T-channel calcium blocker that is a vasodilator with negative chronotropic properties. Included in this study were 114 patients with chronic stable angina pectoris and ischemic episodes during baseline 48-hour ambulatory ECG monitoring (AEM). After a placebo run-in period patients received 50 mg, 100 mg, or 150 mg of mibefradil per day and repeat 48 hours AEM was performed. Ischemic episodes were divided into 2 categories: Type I is those in which an increase in heart rate > 10% preceded the development of 1 mm ST depression; Type II is those with < or = 10% increase in heart rate. Of the 625 ischemic episodes recorded at baseline, 83% were Type I and 17% were Type II. At 50 mg mibefradil dose, there was a significant decrease in the number of Type I ischemic episodes but not of Type II. At doses of 100 mg and 150 mg/day, there was a significant decrease in frequency of both types of ischemic episodes. At a low dose of 50 mg/day, mibefradil reduces ischemia predominantly by preventing an increase in heart rate, while at higher doses of 100 mg and 150 mg/day, it also acted as a vasodilator suppressing episodes associated with increased coronary tone.
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PMID:The effect of mibefradil on ischemic episodes with and without increase in heart rate. 1110 Nov 92

Ranolazine is a novel antianginal agent currently under investigation as monotherapy and adjunct therapy for the treatment of chronic stable angina. Although the mechanism of action of ranolazine is not completely understood, it is believed to involve a reduction in fatty acid oxidation, ultimately leading to a shift in myocardial energy production from fatty acid oxidation to glucose oxidation. Because the oxidation of glucose requires less oxygen than the oxidation of fatty acids, ranolazine can help maintain myocardial function in times of ischemia. In addition, ranolazine does not significantly affect blood pressure, heart rate, or cardiac conduction. The clinical data with ranolazine focuses on its use in chronic stable angina, where it has been shown to increase exercise tolerance and decrease angina compared with placebo and in combination with beta-blockers and calcium-channel blockers. The use of ranolazine for other cardiac conditions and the effect of ranolazine on morbidity and mortality remain to be determined.
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PMID:Ranolazine: a potential new treatment for chronic stable angina. 1197 3

EECP is a non-invasive outpatient treatment for cardiovascular disease refractory to medical and/or surgical therapy. It has been cleared by the Food and Drug Administration for the treatment of a variety of cardiac conditions including congestive heart failure and chronic stable angina. A course of therapy consists of 35 one-hour treatments given once or twice daily. Augmented diastolic pressure and retrograde flow improve myocardial perfusion, while systolic unloading reduces cardiac workload and oxygen requirements. As a result of this treatment, most patients experience increased time to onset of ischemia, increased exercise tolerance, a reduction in the number and severity of anginal episodes, and improved quality of life. Evidence has been presented that this effect lasts well beyond the immediate post-treatment period with some patients symptom-free for several years. Because patients principally seek medical care to live longer or feel better, heart programs need to offer their patients the latest medical advances which have the potential of improving patient survival and health status (symptoms, functioning, and quality of life). Heart programs face a challenging economic future. Increased competition makes it necessary to implement strategies for market differentiation. Those programs most attuned to what their patients define as critical to quality would be most likely to succeed. Over the past decade, there have been a growing number of patients with chronic angina who have exhausted the standard revascularization armamentarium. Because coronary artery bypass grafts occlude and restenosis occurs at angioplasty sites, many patients no longer have suitable coronary anatomy for additional procedures. Also, as the population ages, the proportion of patients with diffuse coronary disease, congestive heart failure, significant co-morbid illness, and poor functional status increases. The incapacitating effects of angina on patients' abilities to work, maintain regular social interactions, and participate in the usual activities of daily living are well described. In spite of the ongoing successes of catheter-based revascularization techniques, the population of patients with intractable angina continues to grow; and ironically, advancements in medical therapy have resulted in an increasing number of patients who are living with severe left ventricular dysfunction and congestive heart failure. Recent studies have estimated that approximately 5-15% of patients undergoing coronary angiography may be considered to have advanced coronary artery disease. Considering that 1,713,000 cardiac catheterizations were performed in 1996 in the United States, approximately 100,000-250,000 patients per year may be eligible for newer treatments for coronary artery disease. More recent statistics in the AHA Heart and Stroke Update report that in 2001, nearly one million patients had coronary artery bypass graft surgery or percutaneous coronary intervention, (Figure 1). Of these, 125,650 patients experienced persistent angina.
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PMID:Enhanced external counterpulsation--a therapeutic option for patients with chronic cardiovascular problems. 1250 Apr 19

Angiogenic gene therapy for stable angina is aimed at promoting new blood vessel formation in the heart, thus providing enhanced cardiac perfusion, symptom relief, increased exercise capacity, improved quality of life, and reduced risk of coronary events. Ad5FGF-4 is a replication-deficient serotype 5 adenovirus encoding the gene for fibroblast growth factor-4 (FGF-4) driven by a cytomegalovirus promoter. In preclinical studies using a pig model of myocardial ischemia, a single intracoronary infusion of Ad5FGF-4 improved cardiac contractile function and regional blood flow in the ischemic region during stress. These effects were apparent after 2 weeks and maintained for > or =12 weeks. Histologic evidence of capillary angiogenesis was observed. FGF-4 gene expression was detected in the heart but not at extracardiac sites. Placebo-controlled trials in humans with chronic stable angina indicate that Ad5FGF-4 increases treadmill exercise duration and improves stress-related ischemia measured by perfusion sestamibi single-photon emission computed tomography. More patients receiving Ad5FGF-4 than placebo reported complete resolution of their angina and no nitroglycerin use. Ad5FGF-4 gene therapy was well tolerated. The administration procedure did not cause any adverse events, although mild, transient fever, a transient modest fall in platelet count, and a transient mild elevation in hepatic enzymes and uric acid levels occurred in a few patients. This adverse event profile concurs with other adenoviral gene trials. There was no evidence of myocarditis, retinal neovascularization, or angioma formation. FGF-4 was not detected in venous blood. Larger clinical trials will assess Ad5FGF-4 with regard to cardiovascular prognosis, symptom relief, and safety profile in patients with chronic stable angina.
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PMID:Angiogenic gene therapy with adenovirus 5 fibroblast growth factor-4 (Ad5FGF-4): a new option for the treatment of coronary artery disease. 1461 23

In humans, regional myocardial dysfunction during ischemia may be improved by ischemic and pharmacological preconditioning. We assessed the possibility that exercise- and nitroglycerin-induced myocardial preconditioning may improve global cardiac performance during subsequent efforts in patients with angina. Ten patients suffering from chronic stable angina and ten healthy volunteers were studied. Through impedance cardiography we assessed hemodynamics during a maximal exercise test, which was used as a baseline (Bas test) and considered as a preconditioning exercise. The Bas test was followed by a sequence of maximal efforts performed during the first (FWOP; 30 min after the Bas test) and second (SWOP; 48 h after the Bas test) windows of protection conferred by ischemic preconditioning. Hemodynamics was further evaluated during maximal exercise performed 48 h later with pharmacologically induced SWOP (PI-SWOP) obtained by transdermal administration of 10 mg of nitroglycerin. In the angina patients, FWOP, SWOP, and PI-SWOP delayed the time to ischemia and allowed them to achieve higher workloads compared with the Bas test. Furthermore, heart rate and cardiac output at peak exercise were enhanced during all the preconditioning phases with respect to the Bas test. However, only SWOP and PI-SWOP increased myocardial contractility and stroke volume. No changes in hemodynamics were detectable in the control subjects. This study demonstrates that in patients with stable angina, although hemodynamics during exercise can be positively improved during both FWOP and SWOP, differences exist between these two phases. Furthermore, the mimicking of exercise-induced SWOP by PI-SWOP with transdermal nitroglycerin may represent an important clinical aspect.
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PMID:Exercise-induced and nitroglycerin-induced myocardial preconditioning improves hemodynamics in patients with angina. 1501 35

Despite increasing pharmacological and mechanical treatment options, ischemic heart disease continues to be associated with considerable patient mortality and morbidity. The estimates of the direct and indirect costs associated with chronic stable angina amount to billions of dollars. Given the epidemiological and economic magnitude of the problem, the need for more effective therapies is self-evident. Based on current guidelines, the management of ischemic heart disease has progressively broadened to include risk factor modification, patient education, and pharmacological therapy. The latter includes i) classic antianginal agents such as beta-blockers, calcium antagonists, and nitrates, and ii) drugs for secondary prevention, such as aspirin, clopidogrel, statins, and angiotensin-converting enzyme inhibitors. Tailoring therapy to individual needs has become even more challenging because of the marked changes in the clinical profile of patients with chronic ischemic heart disease. Compared with the past, today's patients tend to be older, to have undergone revascularization procedures, and to frequently have associated illnesses, including heart failure and diabetes. Significant progress has been made in recent years in understanding the role of cardiac energy metabolism in the pathogenesis of myocardial ischemia. A better understanding of metabolic derangements associated with ischemia and reperfusion is translating into innovative therapeutic approaches. Optimization of cardiac energy metabolism is based on promoting cardiac glucose oxidation. This has been proved to enhance cardiac function and protect myocardial tissue against ischemia-reperfusion injury. A new class of metabolic agents, known as the 3-ketoacyl coenzyme A thiolase inhibitors (trimetazidine), is able to elicit an increase in glucose and lactate combustion secondary to partial inhibition of fatty acid oxidation, producing clinical benefits in patients with ischemic heart disease.
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PMID:["Persistent" angina: rationale for a metabolic approach]. 1507 76


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