Episodes Of Transient Myocardial Ischemia Research Articles

Features of the course of stable exertional angina against the background of iron deficiency anemia in outpatient practice

Introduction. Iron-deficiency accompanies many diseases, including cardiovascular pathology, so timely diagnosis and correction of this condition is necessary. Aim. To study the features of the course of stable exertional angina against the background of iron deficiency anemia before and after correction with iron (III) polymaltose hydroxide in patients in primary health care using a computerized patient register. Materials and methods. 1210 patients with stable exertional angina aged 50–85 years (309 men, 901 women) were included. A special computer program was created for data analysis. In 500 out of 1210 patients, IDA was detected (385 women, 115 men). Mild anemia – 410 patients, moderate – 75, severe – 15. The main group – patients with stable exertional angina and Irondeficiency anemia (the first subgroup – patients treated with iron (III) polymaltose hydroxide and the second subgroup – patients who did not receive the drug iron (III) polymaltose hydroxide due to refusal of treatment or contraindications) and the control group – patients with stable exertional angina without Iron-deficiency anemia. All patients received standard therapy recommended for the treatment of stable exertional angina (the main group additionally received iron (III) polymaltose hydroxide). Results. In the first subgroup of the main group, after treatment with iron (III) hydroxide polymaltose, there was a statistically significant increase in hemoglobin levels by 11,7%, hematocrit by 5%, erythrocytes by 4%, serum iron by 112,8%, and an improvement in exercise tolerance by 48,7%, episodes of ST segment depression by 30,2%. In the second subgroup and the control group, there were no significant changes in the above parameters. Conclusion. Iron-deficiency anemia contributes to the severe course of stable exertional angina, which is confirmed by the high frequency of III-IV functional class exertional angina, a decrease in tolerance to exercise stress. Correction of Iron-deficiency anemia reduces the frequency of episodes of transient myocardial ischemia in the main group.

SILENT MYOCARDIAL ISCHEMIA IN PATIENTS WITH ACUTE CORONARY SYNDROME AND DIABETES MELLITUS

ST-segment elevation myocardial infarction, stenting of the infarct-related coronary artery, silent (painless) myocardial ischemia, diabetes mellitus, 24-hour electrocardiographic monitoring.
 Introduction. Currently, approximately 422 million people in the world have diabetes mellitus, and over 1.3 million individuals in Ukraine are diagnosed with diabetes mellitus. Diabetic neuropathy is known to contribute to the development of atypical and painless variants of ischemic heart disease in individuals with diabetes. This poses a challenge for timely diagnosis and obscures the course of ischemic heart disease, as the prevalence of silent myocardial ischemia is significantly high in these patients. Therefore, the aim of this study is to investigate the occurrence of myocardial ischemia episodes in patients with ST-elevation myocardial infarction within the first day following stenting of the infarct-related coronary artery. Furthermore, we aimed to demonstrate the painless nature of these episodes in the presence of type 2 diabetes mellitus through a clinical case presentation.
 Materials and methods. 30 patients with ST-segment elevation myocardial infarction were examined, and 24-hour electrocardiographic monitoring was performed during the first day after the infarct-related coronary artery stenting. Results. Episodes of transient myocardial ischemia were registered in 50% of people. We found that the majority of episodes (80%) were painless. In the presence of diabetes mellitus, only episodes of painless myocardial ischemia were noted that is supported by the example of a clinical case. The study highlighted the informativeness of 24-hour electrocardiographic monitoring in identifying episodes of myocardial ischemia, particularly in its painless variant. The results demonstrate that patients with ST-elevation myocardial infarction (STEMI) experience episodes of transient myocardial ischemia within the first day after coronary artery stenting, with a majority of these episodes being painless. Furthermore, in the presence of diabetes mellitus, ischemic episodes tend to be painless. Therefore, 24-hour electrocardiographic monitoring serves as a valuable method for the detection of myocardial ischemia.

A retrospective study on prescription pattern of drugs used in myocardial infarction in a South Indian Tertiary Care Hospital

Introduction: Angina pectoris, the primary symptom of ischemic heart disease, is caused by transient episodes of myocardial ischemia that are due to imbalance in the myocardial oxygen supply-demand relationship. Various drugs are prescribed which keeps changing during every decade. This study tries to know the current trends in prescription in myocardial infarction. Material and Methods: About108 patients’ data were collected during the period year 2004-2008 admitted with acute myocardial infarction and data were entered in preformed proforma and were analysed by calculating percentage. Statistical Analysis:Data were interpreted in terms of percentage. Results: The percentage of prescription pattern of various classes of drugs was 91, 66.7, 63.9, 35.2, 31.5, 25, 15.7, 13.9, 12.9, 9.3 and 7.4 for Antiplatelet Agents, Antianginal drugs, Hypolipidemics, Beta receptor antagoist, Angiotensin Converting Enzyme Inhibitors (ACEI), Diuretics, Anticoagulants, Calcium Channel Blockers (CCBs), Angiotensin Receptor Blockers (ARBs), Fibrinolytics and Inotropic drugs respectively. Most of the patients received Aspirin as well as Clopidogrel. Conclusion: Antiplatelet drugs was the most commonly prescribed and alpha blockers were prescribed least as evident from our study. Keywords:Myocardial Infarction, Prescription Pattern, Retrospective Study, Tertiary Care Hospital.

EPIDEMIOLOGY OF ISCHEMIC HEART DISEASE AND ATHEROSCLEROSIS RISK FACTORS IN IMPRISONED MEN

Aim. To reveal prevalence of coronary heart disease (CHD), arterial hypertension (AH) and risk factors for atherosclerosis (RFA) in men sentenced to imprisonment and to evaluate efficacy of secondary prevention for those with CHD and AH. Material and methods. An epidemiological study conducted with 986 imprisoned men at the age 21-69 y.o., included 24-hour blood pressure monitoring (APBM) and ECG monitoring (Holter) within random selection; evaluation of efficacy of complex medical-psychological monitoring (pharmacotherapy + medical enlightenment) in 46 persons with CHD and AH. Results. A high prevalence of CHD was established (15,6%), myocardial infarction (7,6%), AH (49,8%), cardiac rhythm disorders (CRD, 35,3%), borderline psychic disorders (89,2%), smoking (96,0%), alcohol consumption (AC, 96,9%), low physical activity (89,2%), left ventricle hypertrophy (52,3%), anxiety (49,7%), depression (39,5%) and their concomitance (85,0-92,0%); very low level of an existence of AH acknowledgement (10,3%), of CHD (1,6%) and CRD (4,7%). In ABPM and Holter first time were found disorders of 24-hour profile in all persons with AH and also hypertension reactions (66,6%) in normal BP, as deviations of coronary flow — episodes of transient myocardial ischemia (66,6%) and CRD (33,3%). Thanks to the treatment-educational complex, efficacy was marked in 80,0% prisoners of the 1st group, 87,5% — of the 2nd group and 93,3% — of the 3rd. Conclusion. First time a significant prevalence revealed of CHD and AH, of CRD and RFA, significant deviations of peripheral and coronary flow in isolated persons, therapeutical efficacy of secondary prevention (80,0%-93,3%) among prisoners with CHD and AH.

A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis

Each year, an estimated 785,000 Americans will have a new coronary attack, or acute coronary syndrome (ACS). The pathophysiology of ACS involves rupture of an atherosclerotic plaque; hence, treatment is aimed at plaque stabilization in order to prevent cellular death. However, there is considerable debate among clinicians, about which treatment pathway is best: early invasive using percutaneous coronary intervention (PCI/stent) when indicated or a conservative approach (i.e., medication only with PCI/stent if recurrent symptoms occur).There are three types of ACS: ST elevation myocardial infarction (STEMI), non-ST elevation MI (NSTEMI), and unstable angina (UA). Among the three types, NSTEMI/UA is nearly four times as common as STEMI. Treatment decisions for NSTEMI/UA are based largely on symptoms and resting or exercise electrocardiograms (ECG). However, because of the dynamic and unpredictable nature of the atherosclerotic plaque, these methods often under detect myocardial ischemia because symptoms are unreliable, and/or continuous ECG monitoring was not utilized.Continuous 12-lead ECG monitoring, which is both inexpensive and non-invasive, can identify transient episodes of myocardial ischemia, a precursor to MI, even when asymptomatic. However, continuous 12-lead ECG monitoring is not usual hospital practice; rather, only two leads are typically monitored. Information obtained with 12-lead ECG monitoring might provide useful information for deciding the best ACS treatment.Purpose. Therefore, using 12-lead ECG monitoring, the COMPARE Study (electroCardiographic evaluatiOn of ischeMia comParing invAsive to phaRmacological trEatment) was designed to assess the frequency and clinical consequences of transient myocardial ischemia, in patients with NSTEMI/UA treated with either early invasive PCI/stent or those managed conservatively (medications or PCI/stent following recurrent symptoms). The purpose of this manuscript is to describe the methodology used in the COMPARE Study.Method. Permission to proceed with this study was obtained from the Institutional Review Board of the hospital and the university. Research nurses identify hospitalized patients from the emergency department and telemetry unit with suspected ACS. Once consented, a 12-lead ECG Holter monitor is applied, and remains in place during the patient's entire hospital stay. Patients are also maintained on the routine bedside ECG monitoring system per hospital protocol. Off-line ECG analysis is done using sophisticated software and careful human oversight.

A Research Method For Detecting Transient Myocardial Ischemia In Patients With Suspected Acute Coronary Syndrome Using Continuous ST-segment Analysis

Each year, an estimated 785,000 Americans will have a new coronary attack, or acute coronary syndrome (ACS). The pathophysiology of ACS involves rupture of an atherosclerotic plaque; hence, treatment is aimed at plaque stabilization in order to prevent cellular death. However, there is considerable debate among clinicians, about which treatment pathway is best: early invasive using percutaneous coronary intervention (PCI/stent) when indicated or a conservative approach (i.e., medication only with PCI/stent if recurrent symptoms occur). There are three types of ACS: ST elevation myocardial infarction (STEMI), non-ST elevation MI (NSTEMI), and unstable angina (UA). Among the three types, NSTEMI/UA is nearly four times as common as STEMI. Treatment decisions for NSTEMI/UA are based largely on symptoms and resting or exercise electrocardiograms (ECG). However, because of the dynamic and unpredictable nature of the atherosclerotic plaque, these methods often under detect myocardial ischemia because symptoms are unreliable, and/or continuous ECG monitoring was not utilized. Continuous 12-lead ECG monitoring, which is both inexpensive and non-invasive, can identify transient episodes of myocardial ischemia, a precursor to MI, even when asymptomatic. However, continuous 12-lead ECG monitoring is not usual hospital practice; rather, only two leads are typically monitored. Information obtained with 12-lead ECG monitoring might provide useful information for deciding the best ACS treatment. Purpose. Therefore, using 12-lead ECG monitoring, the COMPARE Study (electroCardiographic evaluatiOn of ischeMia comParing invAsive to phaRmacological trEatment) was designed to assess the frequency and clinical consequences of transient myocardial ischemia, in patients with NSTEMI/UA treated with either early invasive PCI/stent or those managed conservatively (medications or PCI/stent following recurrent symptoms). The purpose of this manuscript is to describe the methodology used in the COMPARE Study. Method. Permission to proceed with this study was obtained from the Institutional Review Board of the hospital and the university. Research nurses identify hospitalized patients from the emergency department and telemetry unit with suspected ACS. Once consented, a 12-lead ECG Holter monitor is applied, and remains in place during the patient's entire hospital stay. Patients are also maintained on the routine bedside ECG monitoring system per hospital protocol. Off-line ECG analysis is done using sophisticated software and careful human oversight.

The metabolic syndrome raises the threshold for cardioprotection

Ischemic preconditioning (IPC) and postconditioning (IPost) describe the cardioprotection elicited by applying transient episodes of myocardial ischemia and reperfusion either prior to or at the end of the sustained index ischemic episode. Whether the heart in the presence of the metabolic syndrome is amenable to the cardioprotective benefits of IPC and IPost is currently unclear. Hearts excised from the WOKW (a model of the metabolic syndrome) and LEW.1W (control) rats were randomized to receive either control, IPC (comprising either 1 or 3 cycles of IPC applied prior to the index ischemic period) or IPost (comprising six 10-s episodes of myocardial ischemia–reperfusion, applied at the end of the index ischemic period).

Effect of free fatty acid inhibition on silent and symptomatic myocardial ischemia in diabetic patients with coronary artery disease

Objective Free fatty acid inhibition with trimetazidine (TMZ) improves myocardial metabolism and myocardial ischemia in patients with coronary artery disease (CAD). Because of its effect on myocardial glucose utilization TMZ may represent a therapeutic option in diabetic patients with CAD. Aim of the present study was to evaluate whether the metabolic effect of TMZ may improve episodes of myocardial ischemia in diabetic patients with CAD. Research design and methods We assessed the effect of TMZ on 24 h ambulatory ECG monitoring (AEM) in 30 patients (22 males and 8 females, mean (SE) age 67 ± 6.5 years) with NIDDM and ischemic cardiomyopathy. Patients were randomized to receive on top of standard therapy either TMZ (20 mg, tds) or placebo (tds) and were evaluated at baseline and after 6 months. Results Patients randomized to TMZ or placebo were comparable regarding demographic data, distribution of CAD, and glicated haemoglobin levels. TMZ significantly reduced the number of episodes of transient myocardial ischemia (− 24% compared to baseline, p < 0.01; − 27% compared to placebo, p < 0.01), and Total Ischemic Burden (− 28% compared to baseline, p < 0.01; − 29% compared to placebo, p < 0.01). TMZ also significantly reduced the number of silent episodes of myocardial ischemia (− 42% compared to baseline and − 39% compared to placebo, p < 0.01) and the time of silent myocardial ischemia/24 h (− 37% compared to baseline and − 35% compared to placebo, p < 0.01). No significant changes in heart rate were detected between baseline, placebo and TMZ evaluations. Conclusions TMZ is effective in reducing silent and symptomatic episodes of transient myocardial ischemia in diabetic patients with CAD on standard anti-anginal therapy.

Section 13: Evaluation and Therapy for Heart Failure in the Setting of Ischemic Heart Disease

Section 13: Evaluation and Therapy for Heart Failure in the Setting of Ischemic Heart Disease

Realizing the clinical potential of ischemic preconditioning and postconditioning

After an acute myocardial infarction (AMI), early reperfusion by thrombolysis or primary percutaneous coronary intervention remains the most-effective strategy for limiting the size of an evolving infarct. The mortality from AMI, however, remains significant, due partly to the lethal reperfusion injury that occurs on reperfusing the ischemic myocardium. Novel cardioprotective strategies are required to target this form of injury. In ischemic preconditioning transient, nonlethal episodes of myocardial ischemia and reperfusion before the index ischemic episode reduce infarct size. The cardioprotective potential of ischemic preconditioning has not been realized in clinical practice because it necessitates an intervention applied before the onset of AMI, which is difficult to predict. A more-amenable approach to cardioprotection is to intervene at the onset of reperfusion, the timing of which is under the control of the operator. In this regard, ischemic postconditioning, in which transient episodes of myocardial ischemia and reperfusion administered at the onset of reperfusion reduce infarct size, constitutes one such intervention. Interestingly, studies suggest that ischemic preconditioning and postconditioning activate the same signaling pathway at the time of reperfusion, thereby offering a common target for cardioprotection. Therefore, the pharmacologic recruitment of this signaling pathway at the time of myocardial reperfusion might allow one to harness the cardioprotective potential of ischemic preconditioning and postconditioning. In this review, we discuss the potential application of ischemic preconditioning and postconditioning in the clinical arena of myocardial ischemia and reperfusion, and examine the common signaling pathways by which this might be achieved.

Effects of drug therapy on cardiac arrhythmias and ischemia in hypertensives with LVH

Left ventricular hypertrophy (LVH) in hypertensive subjects is associated with an increased prevalence of ventricular arrhythmias. To evaluate the effect of antihypertensive treatment on cardiac arrhythmias (CA) and transient episodes of myocardial ischemia (TEMI), we studied 46 hypertensive patients with LVH, divided into four groups randomly treated with enalapril, hydrochlorothiazide (HCTZ), atenolol, or verapamil (SR-V) for 6 months. Office blood pressure and office heart rate values were recorded, in basal conditions, after 1 and 6 months of treatment, and all patients underwent echocardiography, electrocardiographic Holter monitoring, and stress testing. All drugs significantly lowered blood pressure, whereas left ventricular mass index was reduced by atenolol, enalapril, and SR-V, but not by HCTZ. Treatment induced a significant reduction in the number of patients with supraventricular arrhythmias (35 v 15, P < .034, and 28 v 8, excluding patients treated with HCTZ, P < .008). The number of patients with ventricular arrhythmias was also reduced (32 v 16 considering all groups, P < .08, and 24 v 9, excluding patients treated with HCTZ, P < .04). The number of TEMI during Holter monitoring significantly decreased from 47 to 23 ( P = .043) in all patients, and from 39 to 14 ( P = .013) excluding patients treated with HCTZ. In all groups, irrespective of treatment, a reduction of blood pressure, heart rate, and systolic blood pressure/heart rate product measured by exercise stress test was observed. The present study shows that in hypertensive patients with LVH, antihypertensive treatment with atenolol, enalapril and SR-V reduces LVH and decreases the prevalence of CA and TEMI. Treatment with HCTZ during the 6-month study did not alter LVH and did not appear to reduce CA and TEMI.

Safety and efficacy of high-dose adenosine-induced asystole during endovascular AAA repair.

To assess the safety and efficacy of high-dose adenosine administration to increase the precision of endovascular abdominal aortic aneurysm (AAA) repair using a balloon deployed stent-graft. From January 1997 to March 1999, 98 AAA patients (79 men; mean age 71 years, range 62-91) were treated with balloon-expandable stent-grafts under an approved protocol. After placing a temporary transvenous ventricular lead or an external transthoracic pacing electrode, adenosine (24 mg initially) was administered in an escalating dose fashion to induce at least 10 seconds of asystole, during which the proximal stent was expanded. Adenosine dosages ranged from 24 to 90 mg (median 24 mg). Nine (9.2%) self-limiting cardiac events were observed: 2 (2.0%) episodes of transient myocardial ischemia, 2 (2.0%) cases of atrial fibrillation requiring cardioversion, 1 (1.0%) transient left bundle branch block lasting <10 seconds, and 4 (4.1%) prolonged periods of asystole requiring temporary pacemaker activation. There were no cases of bronchospasm or worsening obstructive pulmonary disease, and no patients required inotropic support after adenosine-induced asystole. Cardiac events following adenosine-induced asystole are infrequent, mild, and easily treated. The perioperative use of high-dose adenosine to ensure precise stent-graft placement appears to be a safe method of inducing temporary asystole during endovascular aortic repair.

Effects of four different anti-hypertensive treatments on cardiac arrhythmias and transient episodes of myocardial ischemia in hypertensives with left ventricular hypertrophy

Effects of four different anti-hypertensive treatments on cardiac arrhythmias and transient episodes of myocardial ischemia in hypertensives with left ventricular hypertrophy

Elevated Levels of Plasmin-α2 Antiplasmin Complexes in Unstable Angina

The evidence of elevated levels of several biochemical markers of prothrombotic state in patients with unstable angina suggests that thrombus formation and lysis play a pivotal role in acute coronary syndromes. The clinical syndrome of unstable angina encompasses a variety of clinical presentations of transient episodes of myocardial ischemia. This study was designed to assess plasmin generation in different settings of unstable angina. Evidence of plasmin generation in patients with unstable angina was measured by circulating plasmin-alpha2 antiplasmin complexes (PAP). A second objective was to identify whether PAP levels had a prognostic value to predict outcome. Eighty-five patients admitted to the coronary care unit for unstable angina were classified into three groups. Group A included 26 patients with postinfarction angina; group B comprised 26 patients with new onset angina; and group C included 33 patients with crescendo angina. Mean PAP levels were higher in the three groups compared to healthy controls. A significant correlation was found between levels of PAP and D-dimer, particularly in postinfarction angina (r = 0.6; p <0.0005). This trial adds new insights into the pathophysiology of unstable angina. It demonstrates that plasmin is generated in the different settings of unstable angina but particularly in postinfarction angina patients where a fibrin-rich thrombus is responsible of the symptoms. However, in this series PAP levels do not predict an uneventful outcome neither in the acute phase nor at long term (6 months).

Early continuous ST segment monitoring in unstable angina: prognostic value additional to the clinical characteristics and the admission electrocardiogram.

In unstable angina, clinical characteristics, resting electrocardiography, and early continuous ST segment monitoring have been individually reported to identify subgroups at increased risk of adverse outcome. It is not known, however, whether continuous ST monitoring provides additional prognostic information in such a setting. Observational study of 212 patients with unstable angina without evidence of acute myocardial infarction admitted to district general hospitals, who had participated in a randomised study comparing heparin and aspirin treatment versus aspirin alone. Clinical variables and a 12 lead electrocardiogram (ECG) were recorded at admission, and treatment was standardised to include aspirin, atenolol, diltiazem, and intravenous glyceryl trinitrate, in addition to intravenous heparin (randomised treatment). Continuous ST segment monitoring was performed for 48 h and all inhospital adverse events were recorded. The admission ECG was normal in 61 patients (29%), showed ST depression in 59 (28%) (17 > or = 0.1 mV), and T wave changes in a further 69 (33%). The remaining 23 had Q waves (18), right bundle branch block (four), or ST elevation (one). During 8963 h of continuous ST segment monitoring (mean 42.3 h/patient), 132 episodes of transient myocardial ischaemia (104 silent) were recorded in 32 patients (15%). Forty patients (19%) had an adverse event (cardiac deaths (n = 3), non-fatal myocardial infarction (n = 6) and, emergency revascularisation (n = 31)). Both admission ECG ST depression (P = 0.02), and transient ischaemia (P < 0.001) predicted an increased risk of non-fatal myocardial infarction or death, while no patients with a normal ECG died or had a myocardial infarction. Adverse outcome was predicted by admission ECG ST depression (regardless of severity) (odds ratio (OR) 3.41) (P < 0.001), and maintenance beta blocker treatment (OR 2.95) (P < 0.01). A normal ECG predicted a favourable outcome (OR 0.38) (P = 0.04), while T wave or other ECG changes were not predictive of outcome. Transient ischaemia was the strongest predictor of adverse prognosis (OR 4.61) (P < 0.001), retaining independent predictive value in multivariate analysis (OR 2.94) (P = 0.03), as did maintenance beta blocker treatment (OR 2.85) (P = 0.01) and admission ECG ST depression, which showed a trend towards independent predictive value (OR 2.11) (P = 0.076). Patients with unstable angina and a normal admission ECG have a good prognosis, while ST segment depression predicts an adverse outcome. Transient myocardial ischaemia detected by continuous ST segment monitoring in such patients receiving optimal medical treatment provides prognostic information additional to that gleaned from the clinical characteristics or the admission ECG.

Association of physical fitness and transient myocardial ischemia in patients with coronary artery disease.

To examine the relationship between physical fitness and transient myocardial ischemia (TMI) in the laboratory and during daily life, in a sample of coronary patients with a recent positive exercise test. 47 patients with coronary disease (CAD) participated in laboratory mental and exercise stress testing and 48-hour outpatient Holter monitoring after being withdrawn from ant-ischemic medications. During laboratory testing, left ventricular performance was assessed by radionuclide ventriculography. Physical fitness was assessed by measurement of oxygen consumption during symptom-limited exercise treadmill testing. Higher physical fitness subjects were less likely to exhibit wall-motion abnormalities in response to mental stress (P < .05), and to exercise stress (P < .05) testing. They also had smaller decreases in left ventricular ejection fraction (LVEF) in response to mental stress than less fit subjects (P .056), and exhibited a mean increase in LVEF during exercise, compared to the less fit subjects who exhibited a decrease in LVEF (P < .02). Moreover, higher fit subjects exhibited fewer episodes of TMI (P < .04), for a shorter duration (P < .04), and less total ischemic burden (P < .04) during Holter monitoring. These findings suggest that within a population of CAD patients, higher levels of physical fitness are associated with less TMI assessed in the laboratory and during routine activities of daily living.

Effectiveness of prolonged low dose recombinant tissue-type plasminogen activator for refractory unstable angina

The aim of the present study was to evaluate the effectiveness of prolonged administration of thrombolytic therapy with low doses of recombinant tissue-type plasminogen activator (rt-PA) in patients with refractory unstable angina. Intracoronary thrombosis is often the cause of instability in patients with unstable angina. Thrombolytic therapy has been tested in these patients with conflicting results. Sixty-seven patients with unstable angina refractory to standard antianginal therapy were randomized to receive, in addition to the common antianginal therapy, either rt-PA (0.03 mg/kg body weight per h for 3 consecutive days) plus heparin (to achieve activated clotting time of 250 to 400 s) (36 patients, group A) or the same dose of heparin plus placebo (31 patients, group B). No major bleeding was observed in either group of patients. One patient in group A and four in group B (2.7% vs. 12.9%, p < 0.01) developed acute myocardial infarction during the hospital period. Eight patients in group B underwent emergency coronary artery surgery or angioplasty because of worsening of symptoms. Group A patients had a significant reduction in the occurrence of chest pain compared with those in group B (95% confidence interval -7.2 to -2.1 episodes/3 days, p < 0.01). Patients in group B had a greater number of episodes of transient myocardial ischemia (237 vs. 103, p < 0.01) and a longer total ischemic burden (114 +/- 23 vs. 45.6 +/- 8.9 min/day, p < 0.01) than group A patients. After a mean follow-up of 14 +/- 6 months, group A patients were more frequently angina free and had a lower incidence of readmission to the hospital than group B patients. The combination of heparin and protracted administration of rt-PA at low doses is effective in stabilizing and reducing in-hospital adverse events in patients with unstable angina refractory to antianginal therapy.

804-3 A Double Blind Randomized Trial of a 24 Hour Infusion of Magnesium Sulphate in Unstable Angina

Magnesium (Mg2+) has been shown to reduce coronary spasm, have favorable hemodymamic effects, inhibit platelet function, reduce arrhythmias, modulate autonomic function, reduce catecholamine secretion and to be protective during experimental acute myocardial ischemia. Sixty-two consecutive patients with unstable angina (rest pain &lt; 24 hours, ST/T changes and normal admission CK) were randomized in a double-blind fashion to Mg2+ (8 mmol bolus, then 3.0 mmol/h for 24 hours) or placebo within 12 hours of admission. All patients received aspirin, β blockade, iv nitrates and heparin, provided no contraindications existed. Four consecutive 12 hour urine collections were started at study entry for estimation of catecholamines (n = 31) or β thromboglobulin (n = 31). 84% underwent predischarge angiography. Baseline characteristics and extent of coronary disease were similar in both groups. Serum Mg2+ rose from 0.91 ± 0.02 to 1.71 ± 0.05 mmol/l (mean ± SEM) in the Mg2+ group. CKMB release was less in the Mg2+ group at 6 and 24 hours (28.3 ± 7.4 vs 6.6 ± 1.2 ng/ml at 6 hrs, p &lt; 0.05). Regression of T wave changes on the 24 hour ECGs (compared with admission ECGs) occurred more frequently in the Mg2+ group (11 patients vs 0 patients, p &lt; 0.005). On 48 hour Holter monitoring, a similar proportion had transient myocardial ischemia (TMI) in the two groups (16 (52%) in the Mg2+ group vs 15 (48%) in the placebo group), however there were fewer episodes of TMI in the Mg2+ group (57 vs 118, p &lt; 0.0001) with a median total duration of 31.45 vs 102.73 mins respectively (p = ns). Frequency of ventricular ectopy and non-sustained ventricular tachycardia were similar in both groups. Heart rate variability was significantly lower in the placebo group in the 24 hours following, but not during, the infusion. Epinephrine excretion was lower in the Mg2+ group in the first 12 hour sample (1.05 ± 0.20 vs 1.61 ± 0.41 ng/mmol creat., p &lt; 0.051, with no significant difference in norepinephrine excretion. Urinary β thromboglobulin was similar in both groups in all collections. Thus Mg2+ appears to reduce CKMB release, ECG progression and catecholamines in the acute phase of unstable angina with no effect on β thromboglobulin excretion suggesting that its effect may be mediated via autonomic modulation but not platelet function. A larger scale trial investigating the effect of Mg2+ on mortality is warranted.

Contemporary approaches in medical management of patients with stable coronary artery disease

CAD continues to be the principal cause of mortality in the United States, and the largest group of patients with CAD are those with stable angina. Among this group of patients, the most common manifestation of CAD is presence of transient episodes of myocardial ischemia. The presence of transient ischemia and not the severity of angina has been found to be associated with poor clinical outcome in patients with stable CAD. As part of a global treatment strategy for patients with stable CAD, changes in lifestyle and modification of coronary risk factors should be emphasized as an integral part of treatment. Conventional antianginal therapy is quite effective in controlling anginal attacks. Currently, several drugs and therapeutic strategies are available for the treatment of patients with angina (see Table 5). Nitrates are highly effective antianginal drugs with complex beneficial actions in patients with CAD, but their usefulness is limited by development of tolerance during long-term use. When clinically indicated, the use of nitrates should be supplemented with another longer-acting antianginal drug, such as a beta-blocker or a calcium channel blocker. Based on the available data, beta-blockers, when tolerated, seem to be the most effective antianginal drugs for most patients with stable CAD. Beta-blockers are also the most effective anti-ischemic drugs that reduce the magnitude of myocardial ischemia detected during routine daily activities. Calcium channel blockers are also effective vasodilators and good antianginal drugs. The clinician should become familiar with the different actions that this heterogeneous group of drugs has on the heart and vessels. This knowledge allows the clinician to choose the appropriate combination of different antianginal drugs for patients on an individualized basis. It is also critical to develop the treatment strategy by carefully taking into account other associated medical conditions that are frequently encountered in patients with CAD.

Antihypertensive treatment with felodipine but not with a diuretic reduces episodes of myocardial ischaemia in elderly patients with hypertension

Episodes of transient myocardial ischaemia can frequently be observed in hypertensive patients. To assess the effects of antihypertensive treatment with the calcium antagonist felodipine or the diuretic combination hydrochlorothiazidel triamterene on episodes of ischaemic-type ST-segment depression (ST-D), simultaneous ambulatory electrocardiographic and blood pressure (BP) monitoring was performed in 42 elderly hypertensives without manifest coronary artery disease. All patients (mean age 79 +/- 6 years, office BP > or = 160/95 mmHg) were evaluated off any antihypertensive or anti-ischaemic therapy and after 3 months treatment with either felodipine or the diuretic (randomized, double-blind study) for episodes of significant ST-D (> or = 0.1 mV, duration > or = 1 min, interval > or = 1 min). The reduction in office BP and daytime ambulatory BP was similar for both agents, as was a significant reduction in the heart rate x systolic BP product (DP) over 24 h (felodipine: 12,441 +/- 2076 vs 11,643 +/- 1953 mmHg.min-1; P = 0.048; diuretic: 12,366 +/- 2782 vs 11,062 +/- 2012 mmHg.min-1; P = 0.003). While felodipine significantly decreased the total number of ST-D (from 40 to six episodes; P = 0.03), the total number of ST-D remained unchanged with the diuretic (non-significant increase from 31 to 45 episodes; P = 0.24). The same trend was observed for the number of patients with ST-D.(ABSTRACT TRUNCATED AT 250 WORDS)