Guidelines for training in adult cardiovascular medicine. Core Cardiology Training Symposium (COCATS). Task Force 1: training in clinical cardiology.
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Adult↗
Biomedical subjects
B R Chaitman
Publications and source records attributed to B R Chaitman.
ECG phenomenon called the J wave. History, pathophysiology, and clinical significance.
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Animals↗
Asymptomatic cardiac ischemia pilot (ACIP).
This pilot study demonstrated that (1) patients with CAD and asymptomatic cardiac ischemia can be randomized to medical or revascularization strategies using a complex and demanding protocol, (2) asymptomatic cardiac ischemia can be suppressed in 40-50% of patients with clinically advanced coronary disease with relatively low to moderate doses of medication titrated over a period of 12 weeks (3). Revascularization was the most effective of the treatment strategies studied in reducing ischemia. Any type of therapy, whether it be drugs or revascularization requiring repetitive monitoring with ambulatory ECG or other methods to detect ischemia over a long period of time, will escalate the cost of quality medical care for our patients. Thus, the health care costs implications and treatment of asymptomatic ischemia are enormous. But the apparent cost advantage of treating only symptoms, that is ignoring all ischemia, could disappear if treatment of ischemia reduces the risk of adverse events. The clinical question to be addressed in the future is what is necessary to reduce the cardiac-event rates of death and myocardial infarction in this group of patients? Will more aggressive drug therapy eliminate more ischemia and will therapy directed at the elimination of all detectable ischemia improved clinical outcome better than therapy directed to control angina only? These questions can only be answered by a large clinical trial. The results of such a trial will provide the basis and rationale for safe and effective therapy for patients with coronary disease and evidence of cardiac ischemia. Whatever the answer to this important medical and scientific question is, it will have tremendous economic implications.(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗
Preoperative clinical assessment and dipyridamole thallium-201 scintigraphy for prediction and prevention of cardiac events in patients having major noncardiovascular surgery and known or suspected coronary artery disease.
The aim of this study was to assess the relative prognostic use of clinical risk stratification and intravenous dipyridamole thallium-201 scintigraphy in patients with an intermediate to high prevalence of coronary artery disease (CAD) who have undergone major noncardiovascular surgery, and to assess the effects of medical therapy or coronary revascularization based on the result of this clinical scintigraphic screening on perioperative cardiac morbidity and mortality. Patients (n = 161) with an intermediate to high likelihood of CAD had clinical assessment and intravenous dipyridamole planar thallium-201 testing which was analyzed semiquantitatively. Cardiac events were cardiac death (n = 9), nonfatal myocardial infarction (n = 6), acute pulmonary edema (n = 6), and unstable angina (n = 4). Multiple (> or = 2) clinical risk variables predicted any cardiac event (p = 0.04). Presence of multiple (> or = 2) abnormal thallium-201 segments was the only independent predictor of cardiac death or nonfatal myocardial infarction (p < 0.001), and was the most powerful multivariate predictor of any cardiac event (p < 0.002). Patients with an abnormal dipyridamole thallium-201 scan had a higher risk of perioperative cardiac death, myocardial infarction (18% vs 2%; p < 0.001), or any perioperative cardiac event (27% vs 6%; p < 0.001) when compared with those with a normal scan. Preoperative changes in anti-ischemic therapy or coronary revascularization in 36 of 72 patients with abnormal dipyridamole thallium-201 studies reduced perioperative death or myocardial infarction from 31% to 6% (p < 0.01), and all cardiac events from 47% to 8% (p < 0.001) compared with those in patients without intervention.(ABSTRACT TRUNCATED AT 250 WORDS)
Chi-Square Distribution↗
Gender differences in the noninvasive evaluation and management of patients with suspected coronary artery disease.
OBJECTIVE: To determine if gender-based differences exist in the post-test management and clinical outcome of patients with clinically suspected coronary artery disease who have stress electrocardiographic or myocardial perfusion imaging evaluation. DESIGN: Retrospective cohort study. SETTING: University medical center. PATIENTS: From a cohort of 3975 middle-aged patients referred for outpatient stress testing, 840 (47% women) were evaluated noninvasively for clinically suspected coronary artery disease. MEASUREMENTS: The rates of subsequent diagnostic procedures and the incidence of subsequent coronary revascularization, myocardial infarction, or cardiac death were determined for women and men. RESULTS: Pretest cardiac risk profiles were similar, except hypertension and hypercholesterolemia were more frequent in women. Atypical angina was more common in women than in men (57.5% compared with 44.5%, respectively; P < 0.001). Rates of initial test positivity (defined as exercise-induced horizontal or downsloping ST-segment depression > or = 1.0 mm or > or = 1 reversible thallium-201 defect) were similar in women and men. Compared with men, most women with an initial positive test result had no additional coronary artery disease evaluation (62.3% compared with 38.0%; P = 0.002). Coronary revascularization procedures were done more frequently in men (4.9% [22 of 449] compared with 2.0% [8 of 391]; P = 0.03). Cardiac death or myocardial infarction occurred more often in women during 2 years of follow-up (6.9% [27 of 391] compared with 2.4% [11 of 449]; P = 0.002). CONCLUSIONS: Women with suspected coronary artery disease have fewer additional diagnostic tests than men after an initial abnormal noninvasive stress test result, even though the incidence of typical angina, cardiac risk factors, and initial diagnostic test positivity rates are similar.
Adult↗
The Asymptomatic Cardiac Ischemia Pilot (ACIP) study: design of a randomized clinical trial, baseline data and implications for a long-term outcome trial.
OBJECTIVES: The primary objectives of the Asymptomatic Cardiac Ischemia Pilot were 1) to compare the 12-week efficacy of three treatment strategies to suppress cardiac ischemia, and 2) to assess the feasibility of a prognosis trial in patients with asymptomatic cardiac ischemia. BACKGROUND: Cardiac ischemia has been associated with increased morbidity and mortality. However, most cardiac ischemia is asymptomatic, and although therapeutic strategies ranging from no medication to revascularization are being used to treat ischemia, no prospective study evaluating different treatment strategies has been reported. METHODS: Patients with angiographically documented coronary artery disease and ischemia on exercise and ambulatory electrocardiogram (ECG) in 11 clinical units were randomized to receive angina-guided medical therapy, angina-guided plus ambulatory ECG ischemia-guided medical therapy or revascularization (coronary angioplasty or bypass surgery). Patients were also randomized to receive either diltiazem plus isosorbide dinitrate or atenolol plus nifedipine when possible. After anti-ischemic medication adjustment to control angina, blinded medication was adjusted in the medical therapy groups to eliminate ischemia in the ischemia-guided group. The primary outcome was the absence of ischemia at 12 weeks. Follow-up was scheduled for 1 year. RESULTS: A total of 1,959 patients were screened by ambulatory ECG monitoring; 982 (49%) had asymptomatic ischemia, and 618 (65%) were enrolled in the study. Most patients were men, were > 60 years old and had two or more ischemic episodes, early positive exercise tests and multivessel disease. CONCLUSIONS: Design and baseline data for a pilot study of ischemia treatment strategies are described.
Aged↗
Effects of treatment strategies to suppress ischemia in patients with coronary artery disease: 12-week results of the Asymptomatic Cardiac Ischemia Pilot (ACIP) study.
OBJECTIVES: The Asymptomatic Cardiac Ischemia Pilot (ACIP) study was initiated to determine the feasibility of a large trial in evaluating the effects of treatment of ischemia on outcome (mortality and myocardial infarction). The study was designed to examine the effects of medical treatment to control angina compared with treatment strategies guided by ambulatory electrocardiographic (ECG) ischemia or coronary anatomy. BACKGROUND: Treatments to suppress ischemia (asymptomatic and symptomatic) have not been evaluated in a large prospective, randomized trial. Before undertaking such a trial, issues about recruitment and treatment strategies must be addressed. METHODS: The 618 enrolled patients had coronary artery disease suitable for revascularization, ischemia on stress test and asymptomatic ischemia on ambulatory ECG. Patients were assigned randomly to one of three treatment strategies: 1) angina-guided medical strategy with titration of anti-ischemic medication to relieve angina (angina-guided strategy); 2) angina-guided plus ambulatory ECG ischemia-guided medical strategy with titration of anti-ischemic medication to eliminate both angina and ambulatory ECG ischemia (ischemia-guided strategy); and 3) revascularization by angioplasty or bypass surgery (revascularization strategy). RESULTS: Ambulatory ECG ischemia was no longer present at the week 12 visit in 39% of patients assigned to the angina-guided strategy, 41% of patients assigned to the ischemia-guided strategy and 55% of patients assigned to the revascularization strategy. All strategies reduced the median number of episodes and total duration of ST segment depression during follow-up ambulatory ECG monitoring. Revascularization was the most effective strategy. Treadmill test results were concordant with those of ambulatory ECG monitoring. For most patients in the two medical strategies, angina was controlled with low to moderate doses of anti-ischemic medication, and the majority of patients (65%) in the revascularization strategy did not require medication for angina. CONCLUSIONS: This pilot study demonstrated that cardiac ischemia can be suppressed in 40% to 55% of patients with either low or moderate doses of medication or revascularization and that a large trial is feasible.
Aged↗
Exercise technetium-99m sestamibi tomography for cardiac risk stratification of patients with stable chest pain.
BACKGROUND: This study was designed to evaluate the prognostic value of symptom-limited maximal exercise treadmill testing with tomographic technetium-99m sestamibi (MIBI) myocardial imaging in patients referred for evaluation of stable angina. Exercise stress thallium-201 myocardial imaging provides prognostic information in coronary artery disease subsets including patients with stable chest pain. The prognostic value of exercise technetium-99m MIBI myocardial tomography has not been established. METHODS AND RESULTS: Of 548 consecutive patients with stable angina pectoris who underwent maximal exercise treadmill stress testing in combination with a same-day "rest-stress" tomographic technetium-99m MIBI myocardial imaging protocol, 521 patients were followed for 13 +/- 5 months to determine the univariate and multivariate variables associated with cardiac events and to define their cardiac event-free survival. Ten patients were lost to follow-up (98% complete), and 17 who had coronary revascularization within 6 months of testing were excluded. Major cardiac events occurred in 24 patients (9%)--nonfatal myocardial infarction in 11 and cardiac death in 13. Univariate Cox survival analysis demonstrated significant relative risk (RR) and 95% confidence intervals (CI) for exercise ST segment depression (RR = 2.3; 95% CI, 1.0 to 5.3), an abnormal MIBI scan (RR = 13.8; 95% CI, 1.9 to 102.3), and a reversible MIBI perfusion defect (RR = 3.2; 95% CI, 1.4 to 7.5). Multivariate models demonstrated that both exercise MIBI perfusion abnormalities (RR = 11.9; 95% CI, 1.6 to 89.4) and reversible MIBI perfusion defects (RR = 2.9; 95% CI, 1.2 to 7.0) had independent predictive value. During 1 year of follow-up, cardiac events occurred in only 0.5% of patients with normal MIBI scans compared with 7% of those with abnormal MIBI scans (P < .001). One-year, cardiac event-free survival was 92% in patients with reversible MIBI perfusion defects (P < .01 versus normal), 96% in patients with fixed defects (P < .01), and 93% in patients with combined reversible and fixed MIBI myocardial perfusion abnormalities (P < .02). CONCLUSIONS: As with exercise thallium-201 myocardial imaging, exercise stress technetium-99m MIBI myocardial tomography provides significant independent information concerning the subsequent risk of serious cardiac events (death, myocardial infarction) in patients with stable angina pectoris. The identification of MIBI perfusion abnormalities, in particular, the presence of reversible MIBI defects, was associated with reduced 1-year, event-free survival. The recognized imaging and radiotracer biokinetic differences between thallium-201 and MIBI do not appear to modulate the prognostic value associated with scintigraphic evidence of ischemic myocardial jeopardy in the stable angina population.
Chest Pain↗
Correlation of pharmacological 99mTc-sestamibi myocardial perfusion imaging with poststenotic coronary flow reserve in patients with angiographically intermediate coronary artery stenoses.
BACKGROUND: The physiological assessment of angiographically intermediate-severity stenoses remains problematic. Functional measurements of poststenotic intracoronary Doppler coronary flow reserve can be performed in humans but have not been correlated with hyperemic myocardial perfusion imaging or angiographic data in this patient population. METHODS AND RESULTS: Thirty-three patients undergoing diagnostic quantitative coronary angiography (QCA) for assessment of intermediate-severity coronary artery disease (mean QCA percent diameter stenosis, 56 +/- 14%) were studied. Proximal and distal poststenotic Doppler coronary flow velocities were measured (left anterior descending coronary artery, 16; right coronary artery, 10; left circumflex artery, 7 patients) before and during peak maximal hyperemia with intracoronary adenosine (8 to 12 micrograms). Intravenous pharmacological stress (adenosine, 20 patients; dipyridamole, 13 patients) 99mTc-sestamibi tomographic perfusion imaging was performed within 1 week of coronary flow-velocity studies. kappa statistics were calculated to measure the strength of correlation among coronary flow velocities, perfusion imaging data, and QCA results. QCA stenosis severity (abnormal, > or = 50% diameter stenosis) and poststenotic Doppler coronary flow reserve (ratio of abnormal distal hyperemic to basal flow, < or = 2.0) were correctly correlated in 20 of 27 patients (74%; kappa = .48). QCA stenosis severity and 99mTc-sestamibi imaging (abnormal if one or more reversible myocardial segments were present in the poststenotic zone) were correlated in 28 of 33 patients (85%; kappa = .63). 99mTc-sestamibi imaging results agreed with the basal (nonhyperemic) proximal-to-distal velocity ratio (normal, < 1.7) in 15 of 31 patients (48%; kappa = .17). The strongest correlation occurred between hyperemic distal flow-velocity ratio measurements and 99mTc-sestamibi perfusion imaging results in 24 of 27 patients (89%; kappa = .78). All 14 patients with abnormal distal hyperemic flow-velocity values had corresponding reversible 99mTc-sestamibi tomographic defects. More reversibly hypoperfused segments were present in patients with abnormal poststenotic hyperemic flow-velocity ratios (abnormal, 2.4 +/- 0.7 segments; normal, 0.6 +/- 1.0 segments; P < .05). The number of poststenotic myocardial 99mTc-sestamibi perfusion defects was correlated with the QCA percent cross-sectional area reduction (P < .02) and with minimal luminal diameter (P < .05) of intermediate-severity coronary artery stenoses. CONCLUSIONS: Two technologically diverse functional measures of stenosis severity--Doppler-derived poststenotic hyperemic intracoronary flow reserve and vasodilator stress 99mTc-sestamibi myocardial perfusion imaging--are highly (89%) correlated. The physiological assessment of coronary stenoses of angiographically intermediate severity may be improved by the use of these techniques.
Adenosine↗
Impact of age on clinical outcome and postlytic management strategies in patients treated with intravenous thrombolytic therapy. Results from the TIMI II Study. TIMI II Investigators.
BACKGROUND: Few thrombolytic studies have assessed whether patient age is an indication for routine postlytic cardiac catheterization and revascularization or evaluated the impact of age on 1-year outcome differences after acute myocardial infarction. METHODS AND RESULTS: A secondary analysis of 3339 patients enrolled in the TIMI II trial was performed to identify differences in clinical and coronary angiographic findings and 1-year cardiac event rates among 841 patients < 50 years old, 1639 patients 50 to 64 years old, and 859 patients 65 to 75 years old. Differences in 1-year clinical outcome were assessed among patients randomly assigned to an invasive or a conservative postlytic strategy within each age group. The percentages of patients with a prior history of myocardial infarction, angina, congestive heart failure, hypertension, or diabetes mellitus or an infarction complicated at the time of study entry by shock, pulmonary edema, hypotension, rales more than one third of lung fields, or atrial fibrillation as well as the percentage of female patients (all P < .001) increased with age. Fewer older patients (65 to 75 years) received early (ie, < or = within 2 hours after symptom onset) treatment with recombinant tissue-type plasminogen activator (rTPA), and fewer were eligible for random assignment to immediate or deferred beta-blocker therapy (P = .01). The location of the infarct-related artery and the percentage of patients with patent (ie, TIMI flow grade 2 or 3) or "complete" (ie, TIMI flow grade 3) infarct-related artery flow did not vary with age. The percentage of patients with multivessel disease was greatest in the older patients (P = .001). Cumulative 1-year mortality was low in the youngest patients (2.8%; 99% confidence interval [CI], 1.6% to 4.7%) regardless of whether the infarct location was anterior (3.7%) or nonanterior (1.6%). The highest 1-year mortality occurred in the older patients (13.6%; 99% CI, 10.9% to 16.9%), particularly when the infarct location was anterior (18%). The 42-day rates of reinfarction (P = .85), death (P = .95), or death or reinfarction (P = .99) were similar in patients assigned to the invasive or conservative postlytic treatment strategy, regardless of age group. CONCLUSIONS: Among patients with acute myocardial infarction treated with intravenous rTPA, heparin, and aspirin, there were age-related differences in time to treatment with thrombolytic therapy, use of beta-blockers, extent of coronary artery disease, and 1-year cardiac event rates. Routine use of cardiac catheterization and coronary revascularization does not improve immediate or 1-year outcome in terms of mortality or reinfarction compared with a more conservative strategy in young, middle-aged, or elderly patients similar to those enrolled in TIMI II.
Adult↗
Long-term survival of medically treated patients in the Coronary Artery Surgery Study (CASS) Registry.
BACKGROUND: This study describes the impact of clinical, angiographic, and demographic characteristics on the long-term survival of Coronary Artery Surgery Study (CASS) patients while they were under medical treatment. Revascularization rates for the population are also provided. METHODS AND RESULTS: All CASS patients who had not received heart surgery before enrollment (23,467 patients) were included in this survival analysis while they were under medical treatment or surveillance. Follow-up time ranged from 0 to 17 years (median, 12 years). Long-term vital status is known for 95.8% of these patients. Log-rank tests, Kaplan-Meier survival curves, and Cox proportional-hazards regression are used to describe and assess the impact of patient characteristics on survival. Characteristics that had a significant impact on survival, in order of observed explanatory power, are age, number of diseased vessels, congestive heart failure score, smoking history, ejection fraction, sex, presence of left main coronary artery disease, presence of diabetes, left ventricular wall motion score, presence of other illnesses, history of myocardial infarction, and presence of left main equivalent disease. Overall, 12-year survival for patients with zero-, one-, two- and three-vessel disease is 88%, 74%, 59%, and 40%, respectively. Twelve-year survival for patients with at least one diseased vessel and ejection fractions in the ranges of 50% to 100%, 35% to 49%, and 0% to 34% is 73%, 54%, and 21%, respectively. High myocardial jeopardy, high anginal class, and two or three proximal diseased vessels characterize the profile of patients most likely to have received surgical treatment during follow-up. CONCLUSIONS: These results contribute to the understanding of the natural history of coronary artery disease and are also of historical interest. The poor survival of patients with three-vessel disease and low ejection fractions continues to emphasize the importance of considering revascularization for these patients.
Angioplasty, Balloon, Coronary↗
Comparison of the Asymptomatic Cardiac Ischemia Pilot and modified Asymptomatic Cardiac Ischemia Pilot versus Bruce and Cornell exercise protocols.
The Asymptomatic Cardiac Ischemia Pilot (ACIP) and modified ACIP treadmill exercise protocols were developed to test patients with coronary artery disease and to linearly increase work load between stages. The physiologic changes that occurred with ACIP and modified ACIP were compared to those with the Bruce and Cornell protocols in 28 normal subjects and 16 men with coronary artery disease. The exercise protocols were randomly assigned over 2 days, and gas exchange data were obtained continuously with each test. In normal subjects, the peak heart rate, systolic blood pressure, peak oxygen consumption rate (VO2) and minute ventilation were similar for the 4 protocols tested, with exercise time shortest for the Bruce protocol in comparison with the ACIP, modified ACIP and Cornell protocols (10.2 +/- 3.1 vs 13.4 +/- 4.9, 13.9 +/- 4.5, and 15.0 +/- 4.2 minutes, respectively; p < 0.001). The difference between predicted and observed VO2 was smallest for the ACIP protocol (37.0 +/- 11.0 vs 35.8 +/- 13.5 ml/kg/min) and greatest for the Bruce protocol (41.1 +/- 11.8 vs 36.7 +/- 15.0 ml/kg/min) in normal subjects, as well as in patients with coronary artery disease (ACIP protocol 26.9 +/- 7.1 vs 22.5 +/- 6.7, and Bruce protocol 29.1 +/- 7 vs 22.6 +/- 5.7 ml/kg/min, respectively). The ratio of VO2 to work rate, expressed as a slope, was similar in normal subjects for the 4 protocols tested. However, in patients with coronary artery disease, the slope was 0.84 and 0.83 for the ACIP and modified ACIP protocols, respectively, versus 0.61 and 0.71 for the Bruce and Cornell protocols, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Adult↗
Impact of treatment strategy on predischarge exercise test in the Thrombolysis in Myocardial Infarction (TIMI) II Trial.
Predischarge supine bicycle ergometry was used to assess persistent myocardial ischemia in postinfarction patients who received thrombolytic therapy and were randomized to an invasive versus conservative strategy in the Thrombolysis in Myocardial Infarction (TIMI) II trial. The frequency of ischemic responses in both strategies, and the 1-year prognostic importance of the different exercise test outcomes were examined. At 14 days, the percentage of patients with any adverse outcome (including death, presence of exercise-induced ST-segment depression, or inability to perform the exercise test) was 33.7% of 1,681 randomly assigned to the invasive strategy compared with 34.6% of 1,658 randomly assigned to the conservative strategy (p = 0.57). The 1-year mortality was greater in patients who did not perform the predischarge exercise test (7.7%) than in those who did (1.8%) (p < 0.001); the former were older, and a greater proportion were women, had a more frequent history of myocardial infarction, and more extensive coronary artery disease (p < 0.01 for each comparison). The 1-year mortality in patients with exercise-induced ST-segment depression or chest pain was only 1.4% (3 of 22) among those randomly assigned to the conservative strategy where coronary angiography and revascularization were recommended if the test result was abnormal (relative risk compared with those without ST-segment depression or chest pain 0.6; 99% confidence interval 0.1 to 2.9).(ABSTRACT TRUNCATED AT 250 WORDS)
Angioplasty, Balloon, Coronary↗
Newer concepts in the medical management of patients with congestive heart failure.
Congestive heart failure (CHF) remains a major cause of morbidity and mortality in the United States, especially among the elderly. Although an underlying disturbance in cardiac function can be identified in most patients, manifestations of the disease are greatly influenced by other factors, particularly neurohumoral and peripheral adaptive responses which occur secondary to impaired cardiac function. The renin-angiotensin system (RAS) is integrally involved in the pathophysiology of CHF. Originally considered a humoral system, the RAS is now known to exist and operate within cardiac and vascular tissues. The importance of tissue-specific renin-angiotensin systems in CHF is presently under investigation. Most patients with symptomatic CHF benefit from the administration of an ACE inhibitor. Certain asymptomatic patients, such as those with severe left ventricular (LV) dysfunction and those who are at high risk for LV remodeling after anterior wall myocardial infarction, may also benefit from ACE inhibitor therapy. Diuretics and nitrates improve symptoms and often cardiac output in many patients with CHF. Although many new inotropic agents have been tested in CHF patients, none appear clinically superior to digitalis glycosides. The efficacy of digitalis glycosides in CHF may in part result from sympathoinhibitory properties such as the activation of baroreceptor mechanisms. Despite the fact that many CHF patients die from arrhythmias, treatment of asymptomatic ventricular arrhythmias in these patients is not recommended. Patients with symptomatic or sustained ventricular arrhythmias are best treated by a physician experienced in cardiac electrophysiology. Therapy with beta-blocking drugs for CHF patients is controversial. Anticoagulants are recommended for selected patients with CHF. Finally, exercise therapy may improve functional capacity in some patients with CHF through its effects on peripheral blood vessels and skeletal muscle tissues.
Angiotensin-Converting Enzyme Inhibitors↗
Comparative prognostic value of clinical risk indexes, resting two-dimensional echocardiography, and dipyridamole stress thallium-201 myocardial imaging for perioperative cardiac events in major nonvascular surgery patients.
The relative prognostic value of widely accessible resting two-dimensional echocardiographic ventricular function data has not been compared with recognized clinical and scintigraphic risk markers in patients who are unable to exercise before major nonvascular surgery. To this end, 53 consecutive patients aged 67 +/- 13 years undergoing preoperative evaluation (intraabdominal, 23%; orthopedic, 30%; thoracic, 9%; other, 38%) for known or suspected coronary artery disease were followed up to evaluate the prognostic value of these studies for the perioperative cardiac events (cardiac death [n = 4], myocardial infarction [n = 2], unstable angina [n = 3], and pulmonary edema [n = 8]) that occurred in 13 of the 53 patients (25%). Dipyridamole thallium-201 myocardial redistribution defects occurred in 15 (28%) patients. Resting echocardiographic left ventricular dysfunction was present in 21 (40%) patients. Multivariate analysis of clinical, echocardiographic, and scintigraphic risk predictors revealed that cardiac events were not predicted by clinical variables, including Goldman class or score. Cardiac events were independently predicted only by the presence of significant left ventricular dysfunction on resting two-dimensional echocardiography (p < 0.042) and dipyridamole thallium-201 defect redistribution (p < 0.026). A dipyridamole-induced reversible thallium-201 perfusion defect was predictive of subsequent cardiac death or myocardial infarction (p < 0.02), whereas left ventricular dysfunction on resting echocardiography was predictive of perioperative pulmonary edema (p < 0.023). We conclude that stress thallium-201 perfusion imaging and resting two-dimensional echocardiography provide independent prognostic information in patients undergoing major nonvascular surgery who are at significant risk for ischemic cardiac events and who are unable to perform standard exercise stress tests.(ABSTRACT TRUNCATED AT 250 WORDS)
Aged↗
Five-year angiographic follow-up of factors associated with progression of coronary artery disease in the Coronary Artery Surgery Study (CASS). CASS Participating Investigators and Staff.
OBJECTIVES: The Coronary Artery Surgery Study (CASS) required participants to undergo follow-up angiography at 5 years to identify clinical and angiographic features associated with progression of coronary artery disease. BACKGROUND: The CASS randomized 780 patients at 11 participating clinical centers between an initial strategy of medical therapy versus bypass surgery. Five clinical sites accomplished follow-up angiography in > 50% of their randomized subjects within a 42- to 66-month period after the entry arteriogram (n = 314). METHODS: Qualified clinical site angiographers, using side by side film review, evaluated an average of 13 segments/patient on both arteriograms for initial stenosis severity, morphologic features, lesion location and occurrence of disease progression or occlusion. Progression was defined as further definite narrowing by > or = 15% and occlusion as lesion progression to > or = 98%. Lesions were subcategorized as to whether they were univariate and had or had not been treated with bypass surgery. Multivariate logistic regression analyses were performed. RESULTS: For nonbypassed segments, right coronary artery and left anterior descending artery proximal and midlocations were associated with disease progression. For stenosis-containing segments, the initial severity, a non-left anterior descending artery location and increased treadmill duration predicted progression. Segment occlusion was associated with initial lesion severity, right coronary artery location and subsequent interval myocardial infarction. There were few predictors of progression or occlusion in bypassed arteries, other than initial lesion severity. CONCLUSIONS: Univariate and multivariate associations with lesion progression and occlusion included diabetes, lesion location, elevated cholesterol level, interval infarction and lesion morphology. These angiographic results, collected in a prospective trial, are consistent with known risk factors.
Coronary Angiography↗
Effects of carbon monoxide exposure in patients with documented cardiac arrhythmias.
OBJECTIVE: This study was designed to determine whether carbon monoxide has proarrhythmic effects at rest and during upright exercise in patients with myocardial ischemia and moderate baseline ectopic activity. BACKGROUND: Exposure of patients with documented myocardial ischemia to low levels of carboxyhemoglobin (COHb) alters the myocardial response to exercise. Anecdotal reports from patients with myocardial ischemia have noted the development of arrhythmias related to carbon monoxide exposure. Increased frequency of arrhythmias related to carbon monoxide exposure in patients performing supine bicycle exercise has been recently reported. METHODS: Twenty-eight nonsmoking men and five nonsmoking women with documented coronary artery disease and a minimum of 30 ventricular ectopic beats/h over a 20-h period were studied. Subjects were exposed in a randomized double-blind fashion to either room air or sufficient carbon monoxide to elevate their COHb concentration to 3% or 5% in 1 h, followed by a maintenance exposure to carbon monoxide. The subjects then left the laboratory and resumed their normal daily activity to determine changes in ventricular ectopic beats after carbon monoxide exposure. RESULTS: There was no significant change in the frequency of single ventricular ectopic beats at rest from 115 +/- 28 (in room air) to 121 +/- 31 at 3% COHb to 94 +/- 23 at 5% COHb. Exercise itself increased the frequency of ventricular ectopic beats, but there was no additional effect of carbon monoxide exposure on the exercise-induced increase in isolated ectopic beats or complex ectopic waveforms. Analysis of the data based on grouping of the subjects by the severity of disease (ventricular ectopic beat frequency, ejection fraction, presence of exercise-induced ischemia) indicated no proarrhythmic effect of carbon monoxide. CONCLUSIONS: In patients with frequent ventricular ectopic activity (> or = 30 ectopic beats/h), exposure to carbon monoxide producing either 3% or 5% COHb does not increase arrhythmia frequency of single or multiple beats during rest or exercise.
Aged↗
Race and prognosis after myocardial infarction. Results of the thrombolysis in myocardial infarction (TIMI) phase II trial.
BACKGROUND: To better understand the role of race/ethnicity in survival after acute myocardial infarction, we compared clinical and laboratory data, response to thrombolytic therapy, and clinical outcome in 2885 patients participating in the Thrombolysis in Myocardial Infarction Phase II (TIMI II) Trial among three groups of patients (2564 whites, 174 blacks, and 147 Hispanics). METHODS AND RESULTS: Differences were found in baseline characteristics among the three groups including (1) age (mean age for whites, 57.2 years; blacks, 54.8 years; Hispanics, 52.8 years; P < .001), (2) sex (percentage of women for whites, 17.6; blacks, 28.7; Hispanics, 14.3; P < .001), and (3) risk factor prevalence: current smoking (percent for whites, 49.4; blacks, 62.1; Hispanics, 55.1; P < .003), history of hypertension (percent for whites, 36.6; blacks, 55.7; Hispanics, 39.5; P < .001), and diabetes mellitus (percent for whites, 11.9; blacks, 22.4; Hispanics, 19.7; P < .001). Changes in hemostatic factors 5 hours after infusion of recombinant tissue plasminogen activator (rt-PA) revealed a more profound fall in fibrinogen levels in black patients compared with the response seen in Hispanic or white patients (mean change in fibrinogen +/- SD, mg/dL: 151.3 +/- 107.4, 112.2 +/- 97.0, 109.4 +/- 98.6; P < .001, respectively) without more frequent infarct-related artery patency or hemorrhagic complications. Mortality was similar in the white, black, and Hispanic patients through the first year after adjustment for baseline variables. CONCLUSIONS: TIMI II data yield evidence that (1) corroborates published reports of a high prevalence of classic cardiovascular risk factors among minority patients with acute myocardial infarction, (2) there is a greater decrease in fibrinogen levels 5 hours after the start of rt-PA infusion among black patients than in white and Hispanic patients without evidence of more frequent infarct-related artery patency or hemorrhagic complications, and (3) thrombolytic therapy with appropriate supplemental measures is associated with comparable 1-year mortality in white, black, and Hispanic patients.
Black or African American↗