Asymptomatic Cardiac Ischemia Research Articles

Investigating the relationship between carotid intima-media thickness, flow-mediated dilatation in brachial artery and nuclear heart scan in patients with rheumatoid arthritis for evaluation of asymptomatic cardiac ischemia and atherosclerotic changes.

Cardiovascular disease is the most common cause of death worldwide. In order to prevent and treat heart diseases, we need to estimate the trend of non-cardiac diseases with the cardiovascular system. Arthritis Rheumatoid is a chronic immune/inflammatory process which leads to subclinical atherosclerosis and increases cardiovascular disease. We examined the patients who referred to our nuclear medicine center for MPI and correlated their findings with flow-mediated dilatation (FMD) of the brachial artery and carotid intima-media thickness (CIMT) in arthritis rheumatoid patients. A total 30 known cases with arthritis rheumatoid were referred to our department for MPI and the single-photon emission computed tomography (SPECT) imaging were visually and quantitatively evaluated by two nuclear medicine physicians and the correlation of the measured FMD and CIMT were evaluated and compared with ultrasonography data. Demographic information such as gender, age and sex and medical history (risk factors, cardiovascular sign and symptoms, lab findings, medication etc…) were recorded in questionnaire sheets and were analyzed by SPSS.20. Chi-square and student t-test were used for further analysis. The mean CIMT (R = 0.452 ± 0.07, L = 0.447 ± 0.08) and %FMD (R = 7.22 ± 8.66, L = 6.42 ± 11.88) were measured for all subjects. Age was the only parameter correlated with both right and left CIMT (P = 0.033 and P = 0.024, respectively). Among the patients, 26.7% had mild ischemia (SSS < 8) and 3 of them suffered from active arthritis rheumatoid. All patients with RA showed normal ventricular ejection fraction and normal volumes and among them, 93.3% had normal functional performance (normal wall motion…). Moreover, the mean CIMT and %FMD were not significantly different in ischemic and non-ischemic patients. Among ischemic patients, just the course of the disease was associated with CIMT and none of the parameters was correlated with FMD. There is no significant statistical difference between ischemic and non-ischemic patients and also the functional performance with values of CIMT and FMD. Among all populations, the parameter of age, and in ischemic group, the course of disease were found as the only variable correlated with CIMT.

Robustness of methods for blinded sample size re‐estimation with overdispersed count data

Counts of events are increasingly common as primary endpoints in randomized clinical trials. With between-patient heterogeneity leading to variances in excess of the mean (referred to as overdispersion), statistical models reflecting this heterogeneity by mixtures of Poisson distributions are frequently employed. Sample size calculation in the planning of such trials requires knowledge on the nuisance parameters, that is, the control (or overall) event rate and the overdispersion parameter. Usually, there is only little prior knowledge regarding these parameters in the design phase resulting in considerable uncertainty regarding the sample size. In this situation internal pilot studies have been found very useful and very recently several blinded procedures for sample size re-estimation have been proposed for overdispersed count data, one of which is based on an EM-algorithm. In this paper we investigate the EM-algorithm based procedure with respect to aspects of their implementation by studying the algorithm's dependence on the choice of convergence criterion and find that the procedure is sensitive to the choice of the stopping criterion in scenarios relevant to clinical practice. We also compare the EM-based procedure to other competing procedures regarding their operating characteristics such as sample size distribution and power. Furthermore, the robustness of these procedures to deviations from the model assumptions is explored. We find that some of the procedures are robust to at least moderate deviations. The results are illustrated using data from the US National Heart, Lung and Blood Institute sponsored Asymptomatic Cardiac Ischemia Pilot study.

High sensitive troponin T in individuals with chest pain of presumed ischemic origin

This study was aimed at assessing the bias of high sensitive cardiac troponin T vs. the standard cardiac troponin T in a selected population with chest pain of presumed cardiac origin. Serum cTnT was determined in 132 patients and in 106 apparently healthy controls by both assays. The hs-cTnT outperformed the standard generation assay by: i) allowing a larger and earlier diagnosis of AMI (74.2 percent vs. 64.3 percent patients resulted positive at the final diagnosis of AMI when tested with the hs-cTnT or the std-cTnT assay, respectively); ii) showing a better time-dependent dynamics in patients with AMI due to a higher precision at low concentrations; iii) identifying, within the controls, 6 subjects in whom a further examination revealed the presence of chronic asymptomatic cardiac ischemia. The results underscore the excellent performance of the hs-cTnT assay in our population. The use of this test can thus be strongly recommended in subjects presenting to the emergency unit with chest pain of presumed ischemic origin in order to increase the probability of earlier diagnosis of AMI, especially in non-STEMI.

Intradialytic Hypotension Strikes Again

Intradialytic hypotension (IDH) has plagued hemodialysis (HD) patients and their caregivers since the early days of renal replacement therapy. Its persistence in the current era is evident from the results of the 1426-patient Hemodialysis (HEMO) study in this issue of JASN in which a median of 12.5

The efficacy and safety of clopidogrel in vascular surgery patients with immediate postoperative asymptomatic troponin T release for the prevention of late cardiac events: Rationale and design of the Dutch Echocardiographic Cardiac Risk Evaluation Applying Stress Echo-VII (DECREASE-VII) trial

Major vascular surgery patients are at high risk for developing asymptomatic perioperative myocardial ischemia reflected by a postoperative troponin release without the presence of chest pain or electrocardiographic abnormalities. Long-term prognosis is severely compromised and characterized by an increased risk of long-term mortality and cardiovascular events. Current guidelines on perioperative care recommend single antiplatelet therapy with aspirin as prophylaxis for cardiovascular events. However, as perioperative surgical stress results in a prolonged hypercoagulable state, the postoperative addition of clopidogrel to aspirin within 7 days after perioperative asymptomatic cardiac ischemia could provide improved effective prevention for cardiovascular events. DECREASE-VII is a phase III, randomized, double-blind, placebo-controlled, multicenter clinical trial designed to evaluate the efficacy and safety of early postoperative dual antiplatelet therapy (aspirin and clopidogrel) for the prevention of cardiovascular events after major vascular surgery. Eligible patients undergoing a major vascular surgery (abdominal aorta or lower extremity vascular surgery) who developed perioperative asymptomatic troponin release are randomized 1:1 to clopidogrel or placebo (300-mg loading dose, followed by 75 mg daily) in addition to standard medical treatment with aspirin. The primary efficacy end point is the composite of cardiovascular death, stroke, or severe ischemia of the coronary or peripheral arterial circulation leading to an intervention. The evaluation of long-term safety includes bleeding defined by TIMI criteria. Recruitment began early 2010. The trial will continue until 750 patients are included and followed for at least 12 months. DECREASE-VII is evaluating whether early postoperative dual antiplatelet therapy for patients developing asymptomatic cardiac ischemia after vascular surgery reduces cardiovascular events with a favorable safety profile.

SHA 75. The missed essence: Holistic nursing care

Individuals with both type 1 and type 2 diabetes mellitus (DM) are known to be at high risk for developing coronary artery disease (CAD). The risk is two to three times greater in those with DM compared with those without, and is especially high in women with DM. An additional problem in individuals with DM is that, even with severe underlying CAD, many individuals may have atypical symptoms or be totally asymptomatic, a condition referred to as silent or asymptomatic myocardial ischemia. Asymptomatic myocardial ischemia is frequently found in individuals with known CAD, even in individuals without DM, and is associated with a poorer long term prognosis. The Asymptomatic Cardiac Ischemia Pilot Study demonstrated that asymptomatic ischemia was associated with three times the risk of nonfatal myocardial infarction and six times the risk of myocardial infarction or death. However, asymptomatic myocardial infarction also occurs in a substantial number of individuals without known CAD, particularly those with DM. These individuals have not been diagnosed with CAD and do not have the benefit of anti-anginal therapies or aggressive CAD risk reduction. In the recent Detection of Ischemia in Asymptomatic Diabetics (DIAD) study, 21.6% of older adults with type 2 DM, none of whom had any clinical evidence of CAD, had evidence of myocardial ischemia on single photon emission computed tomography (SPECT) myocardial perfusion imaging. This finding was consistent with earlier studies in the population with type 2 DM. In asymptomatic patients with either type 1 or type 2 DM, asymptomatic myocardial ischemia is also associated with major cardiac events. Importantly, the presence of cardiac autonomic neuropathy, long theorized to have a role in asymptomatic CAD, substantially increases the risk of subsequent cardiac events, with those individuals with both asymptomatic myocardial ischemia and cardiac autonomic neuropathy, being at highest risk.

SHA 74. Silent ischemia in patients with diabetes

Individuals with both type 1 and type 2 diabetes mellitus (DM) are known to be at high risk for developing coronary artery disease (CAD). The risk is two to three times greater in those with DM compared with those without, and is especially high in women with DM. An additional problem in individuals with DM is that, even with severe underlying CAD, many individuals may have atypical symptoms or be totally asymptomatic, a condition referred to as silent or asymptomatic myocardial ischemia. Asymptomatic myocardial ischemia is frequently found in individuals with known CAD, even in individuals without DM, and is associated with a poorer long term prognosis. The Asymptomatic Cardiac Ischemia Pilot Study demonstrated that asymptomatic ischemia was associated with three times the risk of nonfatal myocardial infarction and six times the risk of myocardial infarction or death. However, asymptomatic myocardial infarction also occurs in a substantial number of individuals without known CAD, particularly those with DM. These individuals have not been diagnosed with CAD and do not have the benefit of anti-anginal therapies or aggressive CAD risk reduction. In the recent Detection of Ischemia in Asymptomatic Diabetics (DIAD) study, 21.6% of older adults with type 2 DM, none of whom had any clinical evidence of CAD, had evidence of myocardial ischemia on single photon emission computed tomography (SPECT) myocardial perfusion imaging. This finding was consistent with earlier studies in the population with type 2 DM. In asymptomatic patients with either type 1 or type 2 DM, asymptomatic myocardial ischemia is also associated with major cardiac events. Importantly, the presence of cardiac autonomic neuropathy, long theorized to have a role in asymptomatic CAD, substantially increases the risk of subsequent cardiac events, with those individuals with both asymptomatic myocardial ischemia and cardiac autonomic neuropathy, being at highest risk.

Silent cardiac ischemia.

Between the extremes of those who have no coronary disease and those limited by it are those with documented ischemia but no symptoms. Treating these patients in the "murky middle" generates some important questions. Should we treat patients with no symptoms solely on the basis of test abnormalities? Can we make the asymptomatic person better? What interventions would we use to treat such a disorder? How do we justify the risk, inconvenience, and cost of these interventions? How do we measure the efficacy of our intervention? Treating the asymptomatic person can only be justified if we prevent future events through our intervention. The management of silent ischemia can serve as a model for handling other preventative measures. The following article describes the issues around silent cardiac ischemia and some of the insights obtained in the Asymptomatic Cardiac Ischemia Pilot (ACIP) Study.

Medical and revascularization management in acute coronary syndrome in renal patients.

Despite the high incidence of coronary artery disease in patients with renal impairment, its diagnosis and management remains difficult. The treatment of acute coronary syndrome in this particular group of patients is more complex than in patients with normal renal function. They have a high prevalence of asymptomatic cardiac ischemia. Abnormal baseline electrocardiogram (ECG) findings and nonspecific elevation of cardiac enzymes may be present. Studies are lacking regarding their management mainly because they have been excluded or were not studied as a subgroup in the clinical trials. Thrombolytics are underused during acute myocardial infarction. Heparin, mainly low-molecular weight heparin, for unstable angina and non-Q wave myocardial infarction, should be used with caution because the higher risk for bleeding. Other medications, such as aspirin, metoprolol, and nitroglycerin should be used as in the general population. The newer platelet glycoprotein IIb/IIIa inhibitors may need renal dose adjustment. Revascularization should be pursued if necessary by percutaneous coronary intervention or coronary artery bypass grafting. However, the prognosis and risk of revascularization versus medical therapy have not been determined yet.

Ökonomische Evaluation unterschiedlicher Therapieansätze bei Patienten mit stabiler Angina pectoris bzw. asymptomatischer Myokardischämie auf Basis der Resultate der Asymptomatic-Cardiac-Ischemia-Pilot-(ACIP-)Studie

In patients with stable angina pectoris or silent myocardial ischemia, who had signs of ischemia in ECG during exercise, the Asymptomatic Cardiac Ischemia Pilot (ACIP) study compared 2 types of medication strategies (ischemia-guided and angina-guided) and a strategy of primary revascularization by PTCA or CABG. ACIP substantiated, after 2 years of observation, a clear advantage of the revascularization strategy compared to both drug strategies in terms of clinical effectiveness. This advantage is even more distinct in patients with very severe angiographic results. This is a retrospective, incremental cost-effectiveness analysis from the perspective of the German third party payer (statutory sick funds) on the basis of the ACIP study. The direct costs of the revascularization strategy after 2 years are about 2 to 3 times higher than those of the drug therapies. The incremental cost-effectiveness of the ischemia-guided strategy versus an angina-guided strategy is DM 2,600 per life-year saved. Furthermore, the cost-effectiveness of a revascularization strategy versus an angina guided therapy is DM 15,100 per life-year saved. A primary revascularization strategy is cost-effective in patients with stable coronary artery disease with proven myocardial ischemia and positive angiographic signs.

Cost estimates for treatment of cardiac ischemia (from the Asymptomatic Cardiac Ischemia Pilot [ACIP] Study)

Costs for management of myocardial ischemia are enormous, yet comparison cost and outcome data for various ischemia treatment strategies from randomized trials are lacking and will require cost and resource utilization data from a large prospective trial. The Asymptomatic Cardiac Ischemia Pilot provided feasibility data for planning such a trial and an opportunity to estimate the long-term costs of different treatment strategies. Economic implications for ischemia management were compared in 558 patients with stable coronary artery disease and myocardial ischemia during both stress testing and daily life. Participants were randomized to 3 different initial treatment strategies and followed for 2 years. Based on cost trends over follow-up, costs for subsequent care were estimated. As expected, due to initial procedural costs, at 3 months, estimated costs for revascularization were approximately 10 times greater than costs for a medical care strategy. Extrapolated costs for anticipated resource consumption for care beyond 2 years, however, were approximately 2 times greater for an initial medical care strategy than for initial revascularization. This was due to increased need for drugs and hospitalizations for both late revascularizations and other ischemia-related events. Estimated costs for anticipated care in the medical strategies reached the anticipated cost of the revascularization strategy within 10 years. Because this cost-equal time period is well within the median life expectancy for such a patient population, these findings could have important public health implications and require testing in a full-scale prognosis trial. We anticipate that over the patients’ life expectancy, early revascularization is likely to become either cost-neutral or cost-effective.

Prognostic Significance of Myocardial Ischemia Detected by Ambulatory Electrocardiography, Exercise Treadmill Testing, and Electrocardiogram at Rest to Predict Cardiac Events by One Year (The Asymptomatic Cardiac Ischemia Pilot [ACIP] Study)

Myocardial ischemia identified by ambulatory electrocardiography (AECG), exercising treadmill testing, (ETT), or 12-lead electrocardiogram at rest is associated with an adverse prognosis, but the effect of improving these ischemic manifestations by treatment on outcome is unknown. The Asymptomatic Cardiac Ischemia Pilot (ACIP) study was a National Heart, Lung, and Blood Institute funded study to determine the feasibility of conducting a large-scale prognosis study and to assess the effect of 3 treatment strategies (angina-guided strategy, AECG ischemia-guided strategy, and revascularization strategy) in reducing the manifestations of ischemia as indicated by AECG and ETT. The study cohort for this database study consisted of 496 randomized patients who performed the AECG, ETT, and 12-lead electrocardiogram at rest at both the qualifying and week 12 visits. The effect of modifying ischemia by treatment on the incidence of cardiac events (death, myocardial infarction, coronary revascularization procedure, or hospitalization for an ischemic event) at 1 year was examined. In the 2 medical treatment groups (n = 328) there was an association between the number of ambulatory electrocardiographic ischemic episodes at the qualifying visit and combined cardiac events at 1 year (p = 0.003). In the AECG ischemia-guided patients there was a trend associating greater reduction in the number of ambulatory electrocardiographic ischemia episodes with a reduced incidence of combined cardiac events (r = −0.15, p = 0.06). In the revascularization strategy patients this association was absent. In the medical treatment patients the exercise duration on the baseline ETT was inversely associated with an adverse prognosis (p = 0.02). The medical treatment strategies only slightly improved the exercise time and the exercise duration remained of prognostic significance. In the revascularization group strategy patients this association was absent. Thus, myocardial ischemia detected by AECG and an abnormal ETT are each independently associated with an adverse cardiac outcome in patients subsequently treated medically.

Relation Between Clinical, Angiographic and Ischemic Findings at Baseline and Ischemia-Related Adverse Outcomes at 1 Year in the Asymptomatic Cardiac Ischemia Pilot Study

Objectives. We attempted to investigate the relation between patient characteristics and adverse outcome in patients with ischemia and clinically stable coronary artery disease (CAD).Background. Evidence suggests that cardiac ischemia, detected by exercise stress testing (ETT) and ambulatory electrocardiographic (AECG) monitoring during daily living, identifies a subgroup of patients at increased risk for adverse outcome, but the relation between these ischemia findings and clinical and angiographic characteristics is largely unknown.Methods. We examined the relation between clinical, angiographic and ischemia characteristics at entry with adverse outcome observed at 1 year in the 558 patients enrolled in the Asymptomatic Cardiac Ischemia Pilot (ACIP) study.Results. By the 12-month visit 13.1% of patients had an ischemia-related adverse clinical outcome that included death, nonfatal myocardial infarction or an ischemia-related hospital admission. Multivariate analysis identified only the number of AECG ischemic episodes at entry (odds ratio [OR] 1.06, 99% confidence interval [CI] 1.01 to 1.12, p = 0.002) as an independent predictor of outcome. Assignment to revascularization (as opposed to an initial medical treatment strategy) showed a trend (OR 0.56, 99% CI 0.26 to 1.2, p = 0.05). None of the other baseline clinical, exercise or angiographic variables examined provided additional information relative to adverse outcome.Conclusions. Determinants of adverse outcome, among clinically stable patients with CAD and ischemia induced by stress and daily life were magnitude of AECG ischemia before treatment and, possibly, initial treatment assignment. Among the many other characteristics examined, including age, symptom status and angiographic and exercise variables, none contributed additional independent prognostic information. These two simple variables, which may be modifiable, need further study in a larger trial.(J Am Coll Cardiol 1997;29:1483–9)

Anginal Status and Prediction of Cardiac Events in Patients Enrolled in the Asymptomatic Cardiac Ischemia Pilot (ACIP) Study

We hypothesized that among the patients enrolled in the Asymptomatic Cardiac Ischemia Pilot (ACIP) trial, those who reported angina either within the previous 6 weeks or experienced angina during ambulatory electrocardiographic (ECG) monitoring during activities of daily life or during stress testing would be more likely to experience an adverse cardiac event within a year than those who did not experience angina. Of the 558 patients enrolled in ACIP, 325 (58.2%) reported angina in the previous 6 weeks, 300 (53.8%) had stress-induced angina, and 63 (11.3%) reported angina during activities of daily life associated with ST-segment changes on the 48-hour ambulatory electrocardiogram. Some patients had >1 of these angina symptoms and thus 8 angina status categories were identified. Adverse cardiac events were defined as death, nonfatal myocardial infarction (MI), or hospitalization for ischemic events, which included revascularization not specified by the ACIP protocol. One hundred and sixty-seven patients (29.9%) were asymptomatic (i.e., they never had angina) by our defined criteria. Three hundred ninety-one patients (70.1%) were symptomatic. Symptomatic patients had a higher incidence of death, MI, or hospitalization for ischemic events (15.3% symptomatic vs 7.8% asymptomatic, p = 0.016). History of angina within 6 weeks before randomization was predictive of death, MI, or hospitalization for ischemic event (p = 0.007). This finding was due to a large difference in the need for hospitalizations which would be expected to be driven by the presence of angina. By contrast, angina during ambulatory electrocardiogram or stress test was not predictive of an adverse cardiac event. The asymptomatic status of coronary disease patients who have objective documentation of ischemia is not uniformly defined and many different categories can be identified. In this population of patients with proven coronary artery disease and myocardial ischemia, a history of angina in the previous 6 weeks was a good predictor of an adverse event occurring in the next year.Among patients with proven coronary artery disease, a positive stress test, and asymptomatic cardiac ischemia on the ambulatory electrocardiogram, those who report angina within the previous 6 weeks have an increased risk of adverse cardiac events within 1 year compared with those who do not.

Relation Between Ambulatory Electrocardiographic Monitoring and Myocardial Perfusion Imaging to Detect Coronary Artery Disease and Myocardial Ischemia: An ACIP Ancillary Study

Objectives. This study sought to explore the relation between markers of ischemia detected by ambulatory electrocardiographic (AECG) monitoring and stress myocardial perfusion single-photon emission computed tomography (SPECT).Background. Stress myocardial SPECT and AECG monitoring are both utilized in evaluating patients with coronary artery disease. However, information is limited regarding the relation between the presence and extent of ischemia as detected by these two modalities.Methods. This was an ancillary study of the Asymptomatic Cardiac Ischemia Pilot (ACIP) trial. One hundred six patients with previous coronary angiography underwent AECG monitoring and stress SPECT within a close temporal time period. The frequency and duration of ischemia as assessed by AECG monitoring and the total and ischemic stress-induced myocardial perfusion defect sizes as assessed by SPECT were quantified in separate core laboratories. Multivariate logistic regression and linear regression analysis were used to determine associations between AECG and SPECT abnormalities with regard to angiographic, demographic and treadmill exercise variables.Results. Seventy-four percent of patients with significant (≥50%) coronary artery stenosis had SPECT abnormalities, whereas 61% had ischemia by AECG monitoring. The most important predictors of SPECT abnormalities were severity (p < 0.001) of coronary artery stenosis, followed by total exercise duration (p = 0.016) and patient age (p = 0.04). The only predictor of AECG abnormalities was the presence of ST segment depression on the initial exercise treadmill test (p = 0.021). Only a 50% concordance for normalcy or abnormalcy was observed between the SPECT and AECG results, and no relation was observed between the frequency or duration of AECG ischemia and the quantified total or ischemic myocardial perfusion defect size as assessed by SPECT.Conclusions. Ischemia as detected by AECG monitoring does not correlate with the presence and extent of ischemia as quantified by stress SPECT. Because these techniques appear to detect different pathophysiologic manifestations of ischemia, they may be complementary in more fully defining the functional significance of coronary artery disease and, in particular, which patients are at highest risk for adverse cardiac events.(J Am Coll Cardiol 1997;29:764–9)

A Detailed Angiographic Analysis of Patients With Ambulatory Electrocardiographic Ischemia: Results From the Asymptomatic Cardiac Ischemia Pilot (ACIP) Study Angiographic Core Laboratory

Objectives. The purpose of this Asymptomatic Cardiac Ischemia Pilot (ACIP) data bank study was to characterize angiographic features of coronary pathology of patients enrolled in the ACIP study.Background. Ischemia during ambulatory electrocardiographic (AECG) monitoring is associated with increased morbidity and mortality. Reports relating AECG ischemia to severity or complexity of coronary artery disease are few in number and small in size and have produced conflicting results.Methods. Coronary angiograms from patients with asymptomatic AECG ischemia enrolled in the ACIP study were reviewed at a central core laboratory. Quantitative measurement of percent stenosis and Thrombolysis in Myocardial Infarction flow grades were used to assess the severity of coronary artery disease. Lesions were also evaluated for the presence of intracoronary thrombus, ulceration and lumen contour as indicators of stenosis complexity. In addition, comparisons were made with 27 patients screened for the ACIP study, but who were found ineligible because they did not have AECG ischemia on 48-h Holter monitoring.Results. A total of 329 (75%) of 439 patients with AECG ischemia had multivessel coronary artery disease. Proximal stenoses ≥50% diameter reduction were common in patients with AECG ischemia (62.2%), as were proximal stenoses ≥70% (38.7%). Features suggesting complex plaque were found in 50.1% of patients with AECG ischemia.Conclusions. Multivessel coronary artery disease, severe proximal stenoses and features of complex plaque were observed frequently in patients who exhibited AECG ischemia. The presence of severe and complex coronary artery disease may explain, in part, the increased risk for adverse outcome associated with ischemia during activities of daily life.(J Am Coll Cardiol 1997;29:78–84)>

Optimal treatment of stable angina.

Angina pectoris due to coronary artery disease is a common manifestation of myocardial ischemia. Reduction of oxygen demand (beta-blockers) and relief of coronary vasoconstriction (calcium blocker or nitrate) are additive approaches to controlling ischemia. Risk factor reduction may improve coronary vascular physiology, and ASA reduces the likelihood of thrombosis and myocardial infarction. It is still unclear whether reduction of angina reduces cardiac morbidity and/or mortality. In the Asymptomatic Cardiac Ischemia Pilot Study (ACIP) and Total Ischemic Burden Bisoprolol Study (TIBBS) trials, data suggest benefit from reducing myocardial ischemia. Thus control of angina pectoris is a major goal of the treatment of coronary artery disease.

REVASCULARIZATION IMPROVES OUTCOMES FOR SILENT ISCHEMIA.

What's the optimal treatment for patients with silent ischemia -- revascularization or drug therapy guided by the patient's symptoms? The multicenter Asymptomatic Cardiac Ischemia Pilot (ACIP) Study randomized 558 patients with documented coronary disease to …

Asymptomatic Cardiac Ischemia Pilot (ACIP) Study

We investigated whether the presence and frequency of asymptomatic ischemic episodes recorded during ambulatory ECG (AECG) monitoring could be predicted on the basis of clinical characteristics or exercise treadmill test (ETT) performance in patients with stable coronary disease and whether the estimate of ischemia severity was similar between the AECG and ETT. Patients screened for the Asymptomatic Cardiac Ischemia Pilot (ACIP) study were selected for the current analysis if data were available from 48-hour AECG monitoring as well as from an ETT during which the patient developed > or = 1-mm ST-segment depression. Exercise ECG data were available for 143 of the 910 patients without ischemic episodes and for 659 of the 910 patients with ischemic episodes during AECG monitoring. Angina was more frequent among patients with ambulatory ischemic episodes than among patients without such ischemia (P < .001). Patients with AECG ischemia had a consistently more marked ischemic response on the ETT than patients without AECG ischemia; patients likely to have AECG ischemia could be predicted on the basis of ETT performance characteristics. However, the correlation coefficients between the severity of ischemia estimated by ETT and by AECG were small. There are significant relations between ischemia detected by AECG monitoring and by ETT, but the relations are limited, indicating that the two tests are not redundant to characterize coronary patients. A larger study investigating the prognostic significance of the ischemia identified by each modality, with follow-up for clinical events, will be necessary to determine the most appropriate methods to evaluate patients with stable coronary disease.

Factors limiting the enrollment of women in a randomized coronary artery disease trial. The Asymptomatic Cardiac Ischemia Pilot Study (ACIP) Investigators.

Although it is recognized that women have been underrepresented in clinical trials of cardiovascular disease, the reasons for their limited enrollment have not been elucidated. A prospective tracking system was established in the Asymptomatic Cardiac Ischemia Pilot study (ACIP) to monitor recruitment and identify protocol issues that interfered with the recruitment of women. Patients with stress test evidence for ischemia during the course of routine clinical care were screened for asymptomatic ischemia with an ambulatory electrocardiogram (ECG). Those with at least one episode of asymptomatic ischemia and angiographic evidence of coronary artery disease suited for revascularization could be randomized. Women comprised only 17% of the 1,820 patients screened for asymptomatic ischemia, and only 14% of the 558 patients randomized. The limited number of women screened for ischemia was largely due to the limited number of women (25% of all patients) found to have test evidence for ischemia or coronary artery disease suited for revascularization during the course of routine clinical care. Once patients were identified as having ischemia on stress test and ambulatory ECG, the major difference in eligibility was the difference in disqualifying angiograms, occurring 21/2 times as frequently in women as in men (p < 0.001). The percentage of women recruited was lower than the prevalence of ischemic heart disease in the general population because at participating centers (1) women were found to have ischemia less often than men during the course of routine clinical care, and (2) screening tests for ischemia were less predictive of protocol-defined coronary disease in women than in men.