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Biomedical subjects

B R Chaitman

Publications and source records attributed to B R Chaitman.

At least 73 records · Page 4Linked to original sources
PubMed1996

Methodology of serial ECG classification using an adaptation of the NOVACODE for Q wave myocardial infarction in the Bypass Angioplasty Revascularization Investigation (BARI).

Serial electrocardiographic (ECG) changes are a critical component of the diagnostic algorithm for classification of myocardial ischemic events in large-scale clinical trials. This study describes a computerized serial ECG classification program developed at the St. Louis University Core ECG Laboratory for use in the Bypass Angioplasty Revascularization Investigation (BARI) trial, in which patients with multivessel coronary artery disease were randomized to receive either coronary artery bypass grafting or percutaneous transluminal coronary angioplasty. The St. Louis University program detects and codes serial changes in Q, ST, and T wave items according to Minnesota code (MC) criteria using a modified NOVACODE hierarchical classification system. Measurements using a seven-power calibrated coding loupe are used to generate the MC from a customized software program. Significant minor or major changes are detected by the serial comparison program and referred to a physician coder for verification. Serial comparison coding rules are used to adjust for weaknesses in the standard MC classification system resulting from instability at decision boundaries. Of 4,244 BARI randomized and registry study participants with follow-up ECGs received at the Core ECG Laboratory as of March 1995, a grade 2 MC Q wave progression was noted in 568 participants (13.4%) using MC criteria alone, as compared with 367 (8.6%) after the St. Louis University coding rules were applied. The incidence of grade 1 MC Q wave progressions was 16.4% (697/4,244) versus 6.1% (259/4,244) when the St. Louis University program was applied. Intraobserver variability for grade 2 Q wave progression codes determined from a sample of 812 serial.

Algorithms↗
PubMed1996

Myocardial cell damage by fatty acid ethyl esters.

Fatty acid ethyl ester (FAEE), a myocardial metabolite of ethanol, causes mitochondrial dysfunction in vitro in rabbits. We investigated the effect of these esters on rat heart mitochondria in vitro and in vivo. In vitro studies were conducted to investigate the binding of ethyl oleate (FAEE) to mitochondria and their capacity to hydrolyze these FAEE. In vivo effects of ethyl esters were studied by the direct transfer of [3H]oleate into the myocardium. Mitochondria were prepared from the myocardium of injected rats, and the amount of [3H]oleate bound to them was determined. In another in vivo study, 50 microliters of 50 microM cold oleic acid ethyl ester was injected into the rat myocardium and the histopathological changes induced by oleic acid ethyl ester were examined by light microscopy. Our results show that fatty acid ethyl ester can bind to myocardial mitochondria in vitro as well as in vivo and the mitochondria can hydrolyze FAEE to fatty acid, which is a known uncoupler of oxidative phosphorylation. Of the total ethyl [3H] oleate injected, 8 microM [3H]oleate and 1 microM ethyl [3H]oleate was bound to the mitochondria. Significant myocardial cell damage was first observed on day 4 and markedly increased on day 30 after ethyl ester injection, with cells showing gross deformation and enlargement. However, no significant histopathological changes were observed in the myocardial tissue on day 2 after injection. Our results suggest that the FAEE may damage the myocardial cells as well as the mitochondria and may provide a metabolic link between ethanol abuse and myocardial dysfunction.

Animals↗
PubMed1996

Prognostic value of noninvasive risk stratification in younger and older patients referred for evaluation of suspected coronary artery disease.

OBJECTIVES: The purpose of this investigation is to explore the relationship of patient gender and age on coronary artery disease diagnostic evaluation and to assess the impact of noninvasive testing results on coronary revascularization rates and cardiac event-free survival. STUDY DESIGN: Retrospective observational cohort. PARTICIPANTS: From a series of 5322 consecutively tested patients from a Midwestern university tertiary medical center, a hospital cohort of 1345 patients with clinically suspected coronary artery disease was enrolled from 1988 through 1989. MEASUREMENTS AND RESULTS: Cardiac risk factor and symptom profiles were worse in women, whereas rates of positive test results were similar in both sexes. Multivariable-adjusted risk for follow-up diagnostic testing was 1.8 and 1.9 times greater, respectively, for men < or = and > 65 years of age than for women (P < .01). Younger women were 4.9 times (P = .001) more likely to experience a cardiac event than younger men, with no differences between younger and older women (relative risk = 1.1; P > .20). Overall cardiac event rates were 2.3, 7.4, 16.7, and 20.2% for young men, young women, older women, and older men, respectively. Initial screening was delayed 2 to 7 times longer for older and younger women compared with men (P < .001); the greatest delays were observed for younger women. Diagnostic follow-up and subsequent cost of total care from initial evaluation through 2 years of follow-up were higher for men than for women (P < .0001), with older women having the lowest rate of subsequent diagnostic and interventional follow-up. In the highest risk patients, subsequent utilization rates were 40 and 20% higher for younger and older men than for similarly aged women. In particular, diabetics were less likely to undergo follow-up diagnostic testing and revascularization (67% younger women). CONCLUSIONS: Age appears to significantly and differently influence decisions regarding noninvasive and invasive medical service utilization in men and women and may partially account for variable outcomes in this and previous gender-based comparisons.

Adult↗
PubMed1995

Asymptomatic Cardiac Ischemia Pilot (ACIP) Study. Improvement of cardiac ischemia at 1 year after PTCA and CABG.

BACKGROUND: Cardiac ischemia on the ambulatory ECG (AECG) and/or on the exercise treadmill test (ETT) is associated with an increased risk of adverse outcome. Myocardial revascularization more often suppresses cardiac ischemia than does medical management alone. However, few studies have compared the effects of percutaneous transluminal coronary angioplasty (PTCA) with those of coronary artery bypass grafting (CABG) on cardiac ischemia and clinical outcome. METHODS AND RESULTS: A total of 558 patients were randomly assigned to one of three treatment strategies in the Asymptomatic Cardiac Ischemia Pilot (ACIP) study: angina-guided medical strategy (n = 184), ischemia-guided medical strategy (n = 182), or revascularization (n = 192). In patients assigned to revascularization, the choice of the procedure, PTCA or CABG, was made by the clinical unit staff and patient based on a coronary angiogram usually performed within 2 months of enrollment. CABG was selected in 78 patients and PTCA in 92 patients. At 12 weeks, ischemia on the AECG was suppressed in 70% of CABG patients versus 46% of PTCA patients (P = .002). Ischemia on the ETT was no longer present in 46% versus 23% of the patients, respectively (P = .005). Angina, within 4 weeks of the follow-up visit, was absent in 90% versus 68%, respectively (P = .001). These clinical variables remained improved in both groups at 1 year. Clinical events (myocardial infarction or repeat revascularization) occurred in 1 CABG patient versus 7 PTCA patients at 12 weeks, and in 1 versus 16 patients, respectively, at 12 months (P < .001). CONCLUSIONS: Ischemia on the AECG and ETT and angina were relieved in many patients after both procedures; however, CABG was superior to PTCA, and it was associated with a lower incidence of clinical events at 1 year. These results suggest that more complete revascularization relates to better clinical outcome. However, a large trial is needed to confirm these results.

Angina Pectoris↗
PubMed1995

Treatment with bivalirudin (Hirulog) as compared with heparin during coronary angioplasty for unstable or postinfarction angina. Hirulog Angioplasty Study Investigators.

BACKGROUND: Heparin is often administered during and after coronary angioplasty to prevent closure of the dilated vessel. However, ischemic or hemorrhagic complications occur in 5 to 10 percent of treated patients. We studied whether these complications could be prevented when the direct thrombin inhibitor bivalirudin (Hirulog) was used in place of heparin. METHODS: We performed a double-blind, randomized trial in 4098 patients undergoing angioplasty for unstable or postinfarction angina. Patients were assigned to receive either heparin or bivalirudin immediately before angioplasty. The primary end point were death in the hospital, myocardial infarction, abrupt vessel closure, or rapid clinical deterioration of cardiac origin. RESULTS: In the total study group, bivalirudin did not significantly reduce the incidence of the primary end point (11.4 percent, vs. 12.2 percent for heparin) but did result in a lower incidence of bleeding (3.8 percent vs. 9.8 percent, P < 0.001). In the prospectively stratified subgroup of 704 patients with postinfarction angina, bivalirudin therapy resulted in a lower incidence of the primary end point (9.1 percent vs. 14.2 percent, P = 0.04) and a lower incidence of bleeding (3.0 percent vs. 11.1 percent, P < 0.001), but in a similar cumulative rate of death, myocardial infarction, and repeated revascularization in the six months after angioplasty (20.5 percent vs. 25.1 percent, P = 0.17). CONCLUSIONS: Bivalirudin was at least as effective as high-dose heparin in preventing ischemic complications in patients who underwent angioplasty for unstable angina, and it carried a lower risk of bleeding. Bivalirudin, as compared with heparin, reduced the risk of immediate ischemic complications in patients with postinfarction angina, but this difference was no longer apparent after six months.

Aged↗
PubMed1995

Predictors of non-Q-wave acute myocardial infarction in patients with acute ischemic syndromes: an analysis from the Thrombolysis in Myocardial Ischemia (TIMI) III trials.

Among patients with acute ischemic syndromes, patients with non-Q-wave acute myocardial infarction (AMI) are known to be at higher risk for death, reinfarction, and other morbidity than those with unstable angina. The aim of this study was to develop a clinically useful prediction rule to assist in distinguishing, at the time of presentation, patients with non-Q-wave AMI from those with unstable angina. The TIMI IIIB trial enrolled 1,473 patients presenting with ischemic pain at rest within 24 hours who had either electrocardiographic changes or documented coronary artery disease. Non-Q-wave AMI on presentation was documented by elevation of creatine kinase-MB in 33% of patients. Fifty clinical and electrocardiographic variables were compared between the patients with non-Q-wave AMI and unstable angina. After performing logistic regression, 4 baseline characteristics independently predicted non-Q-wave myocardial AMI: the absence of prior coronary angioplasty (odds ratio [OR] = 3.3, p < 0.001), duration of pain > or = 60 minutes (OR = 2.9, p < 0.001), ST-segment deviation on the qualifying electrocardiogram (OR = 2.0, p < 0.001), and recent-onset angina (OR = 1.7, p = 0.002). Using these 4 characteristics, a prediction rule for non-Q-wave AMI was developed. For the entire cohort of patients in TIMI III, the percentages of patients with non-Q-wave AMI when 0, 1, 2, 3, and 4 risk factors were present were 7.0%, 19.6%, 24.4%, 49.9%, and 70.6%, respectively (p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1995

Early and 1-year clinical outcome of patients' evolving non-Q-wave versus Q-wave myocardial infarction after thrombolysis. Results from The TIMI II Study.

BACKGROUND: There are few data comparing clinical outcome and potential indications for routine post-myocardial infarction cardiac catheterization and revascularization of patients who sustain a non-Q-wave versus Q-wave infarct after thrombolytic therapy. METHODS AND RESULTS: A secondary analysis of 2634 patients enrolled in the TIMI II trial with a first myocardial infarction was performed to determine 6-week and 1-year cardiac event rates and identify clinical and angiographic differences between the 1867 patients (70.9%) who evolved a Q-wave infarct and the 767 patients (29.1%) who sustained a non-Q-wave infarct after treatment with intravenous thrombolytic therapy. Male sex (85.3% versus 75.6%; P < .001) and anterior wall infarcts (53.8% versus 43.7%; P < .001) were more frequent in the Q-wave versus the non-Q-wave group. During recombinant tissue-type plasminogen activator (rTPA) infusion, a greater percentage of non-Q-wave patients (37.3% versus 23.5%; P = .001) had normalization of initial ST-segment elevation. Infarct-related artery patency (TIMI flow grade 2 or 3) (P = .02), complete infarct-related artery reperfusion (TIMI 3 flow grade) (P < .001), and the percentage of patients with a predischarge resting left ventricular ejection fraction > 55% (P < .001) were greater in the non-Q-wave group. New congestive heart failure during hospitalization developed more frequently in Q-wave patients (18.9% versus 11.6%; P < .001). After 42 days, the occurrences of reinfarction (P = .76), death (P = .76), and combined death or reinfarction (P = .43) were similar in patients assigned to the invasive or conservative postlytic management strategy, regardless of infarct type. One-year mortality was 3.4% versus 4.4% for non-Q-wave versus Q-wave infarct type, respectively (P = .25). CONCLUSIONS: Angiographic and clinical differences were observed between patients who present with initial ST-segment elevation and evolve early non-Q-wave versus Q-wave myocardial infarcts after treatment with rTPA, heparin, and aspirin. Early mortality and adverse clinical cardiac events in these patients are not significantly different after a conservative compared with an invasive treatment strategy, regardless of whether the infarct type is non-Q wave or Q wave.

Angioplasty, Balloon, Coronary↗
PubMed1995

Long-term prognostic value of exercise testing in men and women from the Coronary Artery Surgery Study (CASS) registry.

Many prior studies involving a predominantly male population have demonstrated the importance of exercise test results in determining the outcome of patients with coronary artery disease. The prognostic significance of exercise testing in women is unknown. In our study, a total of 3,086 men and 747 women underwent maximal treadmill exercise testing, coronary angiography, and were prospectively followed for up to 16 years. They were divided into 3 groups (high, intermediate, and low risk) on the basis of exercise testing. Sixteen-year survival based on exercise test groups ranged from 38% to 61% in men and from 44% to 79% in women (p < 0.001). Among men, 12-year survival was enhanced by coronary artery bypass surgery versus medical therapy in the high-risk subgroup (69% vs 55%, respectively, p = 0.0025), but the 2 therapies were similar in the intermediate- and low-risk subgroups. Among women, neither medical nor surgical therapy resulted in improved 12-year survival rates in any of the 3 subgroups. These results suggest that exercise testing is helpful in assessing long-term survival in men and women. However, only exercise testing in men could identify a high-risk subset whose survival was enhanced by coronary artery bypass graft surgery.

Adult↗
PubMed1995

Comparison of surgical and medical group survival in patients with left main coronary artery disease. Long-term CASS experience.

BACKGROUND: Observational and randomized studies designed to compare surgical and medical therapies in patients with left main coronary artery disease (LMCD) have shown that coronary artery bypass graft (CABG) surgery prolongs life in most patients with LMCD. The present report of 1484 patients with LMCD in the Coronary Artery Surgery Study (CASS) Registry extends the originally published 5-year surgical and medical group survival analysis to more than 16 years of follow-up and permits analysis of LMCD patient subgroups. METHODS AND RESULTS: The CASS Registry contains 1484 patients with > or = 50% left main coronary artery stenosis initially treated with either surgical or nonsurgical therapy. The 15-year cumulative survival estimates were 37% for the 1153 patients in the surgical group compared with 27% for the 331 patients in the medical group. Median survival in the surgical group was 13.3 years (12.8 to 13.8 years, 95% confidence limits) compared with only 6.6 years (5.4 to 7.9 years) in the medical group (difference, 6.7 years; P < .0001). Median survival was also significantly longer in the surgical group stratified by age, sex, anginal class, left ventricular (LV) function, coronary anatomy, and the extent of LMCD. However, CABG surgery did not significantly prolong median survival in patient subgroups with (1) left main coronary stenosis of 50% to 59%; (2) normal LV systolic function; (3) normal or mildly abnormal LV systolic function and a right coronary artery stenosis > or = 70%; and (4) a nonstenotic (< or = 70%) right coronary artery. The 15-year cumulative survival for patients with normal LV systolic function in the surgical and medical groups was 42% and 51%, respectively. Median survival was 14.7 years in the surgical group and > 15 years in the medical group (P = NS). In patients with normal LV systolic function and a right coronary artery stenosis > or = 70%, the 15-year cumulative survival rates were also similar in the surgical and medical groups (40% and 48%, respectively). Median survival was 14.3 years in the surgical group and 14.2 years in the medical group (P = NS). The 15-year cumulative survival estimates for all subgroups were affected by convergence of the surgical and medical survival group curves owing to a disproportionate increase in the late surgical group mortality. Overall, 25% of patients in the medical group ultimately underwent CABG surgery. If all medical group patients had survived long enough, about 47% would be estimated to have had surgery by 15 years. CONCLUSIONS: This report, which extends follow-up of more than 16 years in CASS Registry patients with LMCD, shows that CABG surgery prolongs life in most clinical and angiographic subgroups. However, median survival was not prolonged by CABG surgery in patients with normal LV systolic function, even if a significant right coronary artery stenosis (> or = 70%) also was present. These results extend our understanding of the natural history of LMCD and permit a more accurate estimate of long-term surgical and medical group survival.

Cohort Studies↗
PubMed1995

Comparison of surgical and medical group survival in patients with left main equivalent coronary artery disease. Long-term CASS experience.

BACKGROUND: Combined severe proximal left anterior descending and proximal left circumflex coronary artery disease, or left main equivalent (LMEQ) disease, defines a prognostic high-risk angiographic subset of patients with chronic ischemic heart disease. While numerous observational and randomized clinical trials showed prolonged survival in surgically compared with medically treated patients with left main coronary artery disease, relatively few observational studies compared surgical and medical therapies in patients with LMEQ disease. The present report of 912 patients with LMEQ disease in the Coronary Artery Surgery Study (CASS) Registry extends the originally published 5-year surgical and medical group survival analysis to more than 16 years of follow-up and permits analysis of LMEQ patient subgroups. METHODS AND RESULTS: The CASS Registry contains 912 patients with LMEQ disease, defined as combined stenoses of > or = 70% in the proximal left anterior descending coronary artery before the first septal perforator and proximal circumflex coronary artery before the first obtuse marginal branch, initially treated with either surgical or nonsurgical therapy. The 15-year cumulative survival estimates were 44% for the 630 patients in the surgical group and 31% for the 282 patients in the medical group. Median survival in the surgical group was 13.1 years (12.7 to 14.1 years, 95% confidence limits) compared with only 6.2 years (4.8 to 7.9 years) in the medical group (difference, 6.9 years; P < .0001). Median survival was also significantly longer in the surgical group stratified by age, sex, anginal class, left ventricular (LV) function, and coronary anatomy. However, coronary artery bypass graft (CABG) surgery did not significantly prolong median survival in patient subgroups with (1) normal LV systolic function, even if a significant right coronary artery stenosis (> or = 70%) also was present, and (2) mildly abnormal (LV score, 6 to 10) LV systolic function. The 15-year cumulative survival in patients with normal LV systolic function in the surgical and medical groups was 63% and 54%, respectively. Median survival was > 15 years in both the surgical and medical groups (P = NS). In patients with normal LV systolic function and right coronary artery stenosis > or = 70%, the 15-year cumulative survival was also similar in the surgical and medical groups (63% and 53%, respectively). Median survival was > 15 years in both the surgical and medical groups (P = NS). The 15-year cumulative survival estimates in all subgroups were affected by convergence of the surgical and medical group survival curves caused by a disproportionate increase in late surgical group mortality. Overall, 26% of patients in the medical group ultimately underwent CABG surgery. If all medical group patients had survived long enough, about 65% would be estimated to have had surgery by 15 years. When the CASS Registry patients with LMEQ disease who participated in the randomized trial or who were randomizable were analyzed, CABG surgery did not prolong the 15-year cumulative survival estimates compared with nonsurgical therapy for randomized (71% versus 67%, respectively) and for randomizable patients (62% versus 92%, respectively) with an LV ejection fraction > or = 50%. CONCLUSIONS: This report, which extends follow-up of more than 16 years in CASS Registry patients with LMEQ disease, shows that CABG surgery prolongs life in most clinical and angiographic subgroups. However, median survival was not prolonged by CABG surgery in patients with normal LV systolic function, even if a significant right coronary artery stenosis (> or = 70%) also was present or in patients with an LV ejection fraction > or = 50% who participated in the CASS randomized trial or who were randomizable.

Coronary Angiography↗
PubMed1995

Bypass Angioplasty Revascularization Investigation (BARI): baseline clinical and angiographic data.

This report presents baseline clinical and angiographic data from the Bypass Angioplasty Revascularization Investigation (BARI), a multicenter international trial assessing the relative efficacy of percutaneous transluminal coronary angioplasty (PTCA) versus coronary artery bypass graft surgery (CABG) in selected patients with multivessel coronary artery disease. PTCA is commonly performed in patients with multivessel coronary artery disease, yet its long-term efficacy in comparison to CABG is unknown. From August 1988 through August 1991, 1,829 qualifying patients with multivessel disease suitable for either procedure were randomized to PTCA or CABG; sample size estimates were based on anticipated 5-year mortality. Two registry populations were also defined for follow-up: (1) 2,013 patients eligible for randomization but not randomized; and (2) 422 patients considered by angiography as unsuitable for randomization. Patients randomized in BARI were at relatively high risk for subsequent cardiac events: 39% were > or = 65 years old, 55% had prior myocardial infarction, 69% presented with unstable angina or non-Q wave myocardial infarction, and 43% had 3-vessel coronary artery disease. Patients randomized to PTCA and CABG were equally matched in all the important baseline variables. The randomized and the eligible but not randomized groups were similar in most respects. However, the nonrandomized group had a higher proportion with college education; fewer with a history of myocardial infarction, heart failure, diabetes, and smoking; and a somewhat better average ejection fraction. At the 3-month follow-up, PTCA had been performed more commonly in the nonrandomized eligible patients, especially those with 2-vessel disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗
PubMed1995

Preoperative strategies to assess cardiac risk before noncardiac surgery.

The strategies recommended in the preoperative cardiac risk assessment prior to major vascular and nonvascular surgery are reviewed. The role of clinical evaluation, noninvasive stress testing (exercise test, stress myocardial perfusion imaging, stress echocardiography), and Holter monitoring during the preoperative evaluation are outlined and the value of intervention based on the use of each test is discussed. Recommended strategies to evaluate patients based on their clinical risk markers in addition to the results of the noninvasive risk assessment are presented.

Heart Diseases↗
PubMed1995

Significance of silent myocardial ischemia during exercise testing in women: report from the Coronary Artery Surgery Study.

To evaluate the significance of silent myocardial ischemia during exercise testing in women compared to men, we analyzed the data on 1087 women and 3834 men who underwent exercise testing and coronary angiography from the Coronary Artery Surgery Study (CASS) registry. The patients were divided into three groups on the basis of the results of exercise testing: group 1, silent ischemia (253 women, 853 men); group 2, symptomatic ischemia (156 women, 1250 men); and group 3, no ischemia (678 women, 1731 men). The survival rate at 12 years for women was 80% for group 1, 75% for group 2, and 86% for group 3 (p = 0.0022); the survival rate for men was 69% for group 1, 69% for group 2, and 76% for group 3 (p < 0.001). In both men and women with silent ischemia, the 12-year survival rate was related to the severity of coronary artery disease (CAD) and ranged from 79% for women with one-vessel CAD to 46% for men with three-vessel CAD. Survival at 12 years was enhanced by coronary artery bypass graft surgery as compared to medical treatment in patients with silent ischemia and three-vessel CAD for men (61% vs 46%, respectively, p = 0.0014) but not for women (45% vs 50%, respectively, p = 0.98). These data suggest that silent ischemia in women and men adversely affects survival rate and that men may gain more benefit from coronary artery bypass graft surgery than women when three-vessel CAD is present.

Cardiac Catheterization↗
PubMed1995

Asymptomatic Cardiac Ischemia Pilot (ACIP) study: effects of coronary angioplasty and coronary artery bypass graft surgery on recurrent angina and ischemia. The ACIP investigators.

OBJECTIVES: The Asymptomatic Cardiac Ischemia Pilot (ACIP) study showed that revascularization is more effective than medical therapy in suppressing cardiac ischemia at 12 weeks. This report compares the relative efficacy of coronary angioplasty or coronary artery bypass graft surgery in suppressing ambulatory electrocardiographic (ECG) and treadmill exercise cardiac ischemia between 2 and 3 months after revascularization in the ACIP study. BACKGROUND: Previous studies have shown that coronary angioplasty and bypass surgery relieve angina early after the procedure in a high proportion of selected patients. However, alleviation of ischemia on the ambulatory ECG and treadmill exercise test have not been adequately studied prospectively after revascularization. METHODS: In patients randomly assigned to revascularization in the ACIP study, the choice of coronary angioplasty or bypass surgery was made by the clinical unit staff and the patient. RESULTS: Patients assigned to bypass surgery (n = 78) had more severe coronary disease (p = 0.001) and more ischemic episodes (p = 0.01) at baseline than those assigned to angioplasty (n = 92). Ambulatory ECG ischemia was no longer present 8 weeks after revascularization (12 weeks after enrollment) in 70% of the bypass surgery group versus 46% of the angioplasty group (p = 0.002). ST segment depression on the exercise ECG was no longer present in 46% of the bypass surgery group versus 23% of the angioplasty group (p = 0.005). Total exercise time in minutes on the treadmill exercise test increased by 2.4 min after bypass surgery and by 1.4 min after angioplasty (p = 0.02). Only 10% of the bypass surgery group versus 32% of the angioplasty group still reported angina in the 4 weeks before the 12-week visit (p = 0.001). CONCLUSIONS: Angina and ambulatory ECG ischemia are relieved in a high proportion of patients early after revascularization. However, ischemia can still be induced on the treadmill exercise test, albeit at higher levels of exercise, in many patients. Bypass surgery was superior to coronary angioplasty in suppressing cardiac ischemia despite the finding that patients who underwent bypass surgery had more severe coronary artery disease.

Angina Pectoris↗
PubMed1995

Asymptomatic Cardiac Ischemia Pilot (ACIP) study: impact of anti-ischemia therapy on 12-week rest electrocardiogram and exercise test outcomes. The ACIP Investigators.

OBJECTIVES: This report from the Asymptomatic Cardiac Ischemia Pilot (ACIP) study examines differences in the magnitude of reduction of myocardial ischemia as determined by exercise treadmill testing in patients randomized to three different treatment strategies: angina-guided medical therapy, ischemia-guided medical therapy and coronary revascularization. BACKGROUND: No prospective randomized clinical trials in patients with exercise electrocardiographic (ECG) abnormalities and asymptomatic cardiac ischemia on ambulatory ECG monitoring have compared the impact of different treatment strategies, including coronary revascularization, in terms of reducing myocardial ischemia. METHODS: The ACIP exercise protocol was used. Exercise variables measured included final exercise stage; presence of exercise-induced angina or ischemia; time to angina; time to 1-mm ST segment depression; number of exercise ECG leads with abnormalities; maximal depth of ST segment depression in any lead; sum of ST segment depression; ST/HR index; and rate-pressure product at time to angina, at time to 1-mm ST segment depression and at peak exertion. RESULTS: Peak exercise time was increased by 0.5, 0.7 and 1.6 min in patients assigned to the angina-guided, ischemia-guided and coronary revascularization strategies, respectively, from the qualifying visit to the 12-week visit (p < 0.001). At the qualifying visit, the sum of exercise-induced ST segment depression was 9.4 +/- 5.0 (mean +/- SD), 9.6 +/- 4.7 and 9.9 +/- 5.5 mm (p = NS) in the three treatment strategies, respectively. At the 12-week visit, the sum of exercise-induced ST segment depression was 7.4 +/- 5.7, 6.8 +/- 5.3 and 5.6 +/- 5.6 mm (p = 0.02) in the three treatment strategies, respectively. Each treatment strategy resulted in a significant reduction in all exercise-induced variables of myocardial ischemia measured at 12 weeks. CONCLUSIONS: Coronary revascularization significantly reduced the extent and frequency of exercise-induced myocardial ischemia compared with either medical strategy. The prognostic impact of these observations should be evaluated in a large-scale multicenter clinical trial.

Analysis of Variance↗
PubMed1995

Asymptomatic Cardiac Ischemia Pilot (ACIP) study: outcome at 1 year for patients with asymptomatic cardiac ischemia randomized to medical therapy or revascularization. The ACIP Investigators.

OBJECTIVES: This report discusses the outcome at 1 year in patients in the Asymptomatic Cardiac Ischemia Pilot (ACIP) study. BACKGROUND: Comparative efficacy of medical therapy versus revascularization in treatment of asymptomatic ischemia is unknown. The ACIP study assessed the ability of three treatment strategies to suppress ambulatory electrocardiographic (ECG) ischemia to determine whether a large-scale trial studying the impact of these strategies on clinical outcomes was feasible. METHODS: Five hundred fifty-eight patients with coronary anatomy amenable to revascularization, at least one episode of asymptomatic ischemia on the 48-h ambulatory ECG and ischemia on treadmill exercise testing were randomized to one of three treatment strategies: 1) medication to suppress angina (angina-guided strategy, n = 183); 2) medication to suppress both angina and ambulatory ECG ischemia (ischemia-guided strategy, n = 183); or 3) revascularization strategy (angioplasty or bypass surgery, n = 192). Medication was titrated atenolol-nifedipine or diltiazem-isosorbide dinitrate. RESULTS: The revascularization group received less medication and had less ischemia on serial ambulatory ECG recordings and exercise testing than those assigned to the medical strategies. The ischemia-guided group received more medication but had suppression of ischemia similar to the angina-guided group. At 1 year, the mortality rate was 4.4% in the angina-guided group (8 of 183), 1.6% in the ischemia-guided group (3 of 183) and 0% in the revascularization group (overall, p = 0.004; angina-guided vs. revascularization, p = 0.003; other pairwise comparisons, p = NS). Frequency of myocardial infarction, unstable angina, stroke and congestive heart failure was not significantly different among the three strategies. The revascularization group had significantly fewer hospital admissions and nonprotocol revascularizations at 1 year. The incidence of death, myocardial infarction, nonprotocol revascularization or hospital admissions at 1 year was 32% with the angina-guided medical strategy, 31% with the ischemia-guided medical strategy and 18% with the revascularization strategy (p = 0.003). CONCLUSIONS: After 1 year, revascularization was superior to both angina-guided and ischemia-guided medical strategies in suppressing asymptomatic ischemia and was associated with better outcome. These findings require confirmation by a larger scale trial.

Aged↗