Prediction of death and myocardial infarction by screening with exercise-thallium testing after coronary-artery-bypass grafting

BACKGROUND: The role of myocardial-perfusion imaging in calculating risk in symptom-free patients who have had coronary-artery-bypass grafting (CABG) is unclear. Practice guidelines have argued against routine screening of these patients. We sought to find out the independent and incremental prognostic value of exercise thallium-201 single-photon-emission computed tomography (SPECT) for prediction of death and non-fatal myocardial infarction (MI) in these patients. METHODS: Analyses were based on 873 symptom-free patients undergoing symptom-limited exercise thallium-201 SPECT between September, 1990, and December, 1993. All had undergone CABG and none had recurrent angina or other major intercurrent coronary events. Exercise and thallium-perfusion variables were analysed to determine their prognostic importance during 3 years of follow-up. FINDINGS: Myocardial-perfusion defects were noted in 508 (58%) patients. There were 57 deaths and 72 patients had major events (death or non-fatal MI). Patients with thallium-perfusion defects were more likely to die (9% vs 3%, p=0.0004) or suffer a major event (11% vs 4%, p=0.0002). Reversible defects were also predictive of death (12% vs 5%, p=0.002) and major events (13% vs 7%, p=0.004). The exercise variable with the strongest predictive power was an impaired (< or = 6 METs [measure of oxygen consumption equal to 3.5 mL/kg/min]) exercise capacity; poor exercise capacity was predictive of death (18% vs 4%, p<0.0001) and death or non-fatal MI (19% vs 5%, p<.00001). After adjusting for baseline clinical variables, surgical variables, time elapsed since CABG, and standard cardiovascular risk factors, thallium-perfusion defects remained predictive of death (adjusted relative risk 2.78, 95% CI 1.44-5.39) and major events (2.63, 1.49-4.66). Similarly, impaired exercise remained strongly predictive of death (4.16, 2.38-7.29) and major events (3.61, 2.22-5.87) after adjusting for confounders. INTERPRETATION: In this group of patients who were symptom-free after CABG, thallium-perfusion defects and impaired exercise capacity were strong and independent predictors of subsequent death or non-fatal MI. Recommendations against routine screening exercise myocardial-perfusion studies in this setting should be reconsidered.     

Dipyridamole stress echocardiography and exercise testing for risk stratification after uncomplicated myocardial infarction

BACKGROUND: Risk stratification for subsequent cardiac events after an acute infarction can be obtained by exercise testing or dipyridamole stress echocardiography. It remains to be determined whether these modalities are equivalent and provide incremental information on top of clinical evaluation. The aim of our study was to compare the prognostic information obtained early after an acute uncomplicated myocardial infarction of high dose dipyridamole coupled with echocardiography (stress echo) or maximal symptom-limited exercise testing. METHODS AND RESULTS: Ninety patients underwent dipyridamole stress echo and exercise testing at a mean +/- SD of 9 +/- 4 days after admission for acute uncomplicated first myocardial infarction. All patients were prospectively followed for 22 +/- 16 months. There were 9 hard events (3 cardiac deaths and 6 acute myocardial infarctions) and 12 soft events due to post MI angina (6 angioplasty and 6 bypass surgery procedures). Univariate predictor of hard events was rest-stress wall motion score index variation (p = 0.009); univariate predictors of all events (hard + soft) were: positive exercise testing (p = 0.001), positive stress echo (p = 0.001), rest-stress wall motion score index variation (p = 0.002), extent of ischemia at echo (p = 0.008). Multivariate analysis by Cox selected a non-Q wave infarction and rest-stress wall motion score index variation as predictors of death or reinfarction (overall chi-square for the model 12.2, p = 0.0022). CONCLUSIONS: Stress echo is superior to ergometric variables for predicting events after uncomplicated myocardial infarction.     

Erwin Payr, Hans von Haberer, Ernst Jeger--a set of 3 stars in the universe of vascular surgery]

BACKGROUND: Previous studies have demonstrated the prognostic value of radionuclide ventriculography at rest and exercise in patients post myocardial infarction (MI). The number of studies in patients treated with modern reperfusion techniques, including thrombolysis or primary angioplasty, however, is limited. HYPOTHESIS: The aim of this study was to evaluate the prognostic significance of predischarge radionuclide ventriculography at rest and exercise in patients with acute MI treated with thrombolysis or primary angioplasty. METHODS: A total of 272 consecutive patients with acute MI who were randomized to thrombolysis or primary coronary angioplasty underwent predischarge resting and exercise radionuclide ventriculography. Left ventricular ejection fraction at rest, decrease in ejection fraction during exercise > 5 units below the resting value, angina pectoris, ST-segment depression, and exercise test ineligibility were related to subsequent cardiac events (cardiac death, nonfatal reinfarction) during follow-up. RESULTS: During a mean follow-up of 30 +/- 10 months, cardiac death occurred in 11 (4%) patients and nonfatal reinfarction in 14 (5%) patients. Resting left ventricular ejection fraction was the major risk factor for cardiac death. In patients with an ejection fraction < 40%, cardiac death occurred in 16% compared with 2% in those with an ejection fraction > or = 40% (p = 0.0004). In addition, cardiac death tended to be higher in patients ineligible than in those eligible for exercise testing (11 vs. 3%, p = 0.08). None of the other exercise variables (decrease in ejection fraction during exercise > 5 units below the resting value, angina pectoris or ST-segment depression) were predictive for cardiac death. When all exercise test variables in each patient were combined and expressed as a risk score, a low risk (n = 185) and a higher risk (n = 87) group of patients could be identified, with cardiac death occurring in 1 and 10%, respectively. As the predictive accuracy of a negative test was high, radionuclide ventriculography was of particular value in identifying patients at low risk for cardiac death. Radionuclide ventriculography was not able to predict recurrent nonfatal MI. CONCLUSION: In patients with MI treated with thrombolysis or primary angioplasty, radionuclide ventriculography may be helpful in identifying patients at low risk for subsequent cardiac death. In this respect, left ventricular ejection fraction at rest was the major determinant. Variables reflecting residual myocardial ischemia were of limited prognostic value. Identification of a large number of patients at low risk allows selective use of medical resources during follow-up in this subgroup and has significant implications for the cost effectiveness of reperfusion therapies.     

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)     

One-year outcomes of diabetic versus nondiabetic patients with non-Q-wave acute myocardial infarction treated with percutaneous transluminal coronary angioplasty

Risk factors and outcomes associated with non-Q-wave myocardial infarction (MI) in diabetics and nondiabetics were analyzed for 376 consecutive patients, 77 with diabetes (20%) and 299 nondiabetics (80%), who had non-Q-wave MI and had percutaneous transluminal coronary angioplasty (PTCA) performed before discharge from hospital during the period from January 1992 to February 1996. Diabetics were slightly older (64 +/- 10 years vs 61 +/- 12 years, p <0.053), had more prior coronary artery bypass grafting (CABG) surgery (27% vs 12%, p <0.001), and hypertension (77% vs 49%, p <0.001). There was no significant difference in unstable angina, saphenous vein graft PTCA, single versus multiple vessel disease, or history of MI. PTCA success rates for diabetics versus nondiabetics were similar (96% vs 97%, p = NS). In-hospital complications such CABG, recurrent MI, repeat PTCA, stroke, and death were not statistically significant between the 2 groups. At 1-year follow-up, survival in diabetics (92%) was similar to nondiabetics (94%, p = NS), although event-free survival (PTCA, CABG, MI, death) was worse in diabetics (55% vs 67% for nondiabetics, p <0.05). Although diabetic patients with non-Q-wave MI represent a cohort with more risk factors for poor outcome, aggressive in-hospital revascularization with PTCA results in an excellent short-term outcome as well as 1-year survival similar to the nondiabetic patients. However, total events at 1-year follow-up are more common in the diabetic patients, suggesting that more aggressive screening and therapy in follow-up may be warranted, and that a diabetic with non-Q-wave MI will require increased utilization of cardiovascular resources in the first year after the event.     

Myocardial revascularisation in elderly patients with refractory or unstable angina and advanced coronary disease

BACKGROUND: Elderly patients with ischaemic heart disease are often treated more conservatively and for longer than younger patients, but this strategy may result in subsequent invasive intervention of more advanced and higher risk coronary disease. METHODS: We performed a retrospective analysis of 109 patients aged > or = 70 years (mean age 74 years, 66% men), who presented with angina refractory to maximal medical treatment or unstable angina over a 2-year period (1988-1990), to compare the relative risks and benefits of myocardial revascularisation [coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA)] in this higher-risk age group. RESULTS: Sixty patients underwent CABG and 49 patients PTCA. There were eight periprocedural deaths in total (six in the CABG group, and two in the PTCA group, P = 0.29). Six patients in the CABG group suffered a cerebrovascular accident (two fatal). Acute Q-wave myocardial infarction occurred in one patient in the CABG group and in two patients in the PTCA group. The length of hospital stay was longer for the CABG group (CABG group 11.4 +/- 5.4 days, range 7-30 days, PTCA group 7.4 +/- 7.6 days, range 1-39 days, P = 0.01). Outcome was assessed using the major cardiac event rate (MACE; i.e. the rate of death, myocardial infarction, repeat CABG or PTCA). The cumulative event-free survival in the CABG group in 1, 2 and 3 years was 87, 85 and 85%, respectively. In contrast, in the PTCA group it was 55, 48 and 48% (P = 0.0001). Age, sex, number of diseased vessels, degree of revascularisation and left ventricular function were not predictive of the recurrence of angina in both groups. Actuarial survival (total mortality, including perioperative mortality) was lower at 1 year in the CABG group due to the higher perioperative mortality, but similar in both groups after the second year (P = 0.62). CONCLUSIONS: Elderly patients with refractory or unstable angina who are revascularised surgically have a better long-term outcome (less frequent event rate of the composite end-point--myocardial infarction, revascularisation procedures and death) compared with those who are revascularised with PTCA. This benefit is been realised after the second year. Total mortality is similar in both groups after the second year. Therefore elderly patients who are fit for surgery should not be denied the benefits of CABG. PTCA may be regarded as a complementary and satisfactory treatment, especially for those whose life expectancy is limited to less than 2 years. The use of stents may improve outcome in the PTCA group and this needs to be evaluated.     

A new clinical classification for hospital prognosis of unstable angina pectoris

Unstable angina represents a heterogeneous spectrum of clinical entities between chronic stable angina and acute myocardial infarction. To facilitate prognostication of in-hospital outcome, we prospectively tested on a priori unstable angina classification scheme based on information available at the time of acute presentation. Prospective database enrollment at the time of emergency room presentation was performed and patients were classified into 1 of the following categories: class IA, acceleration of previous exertional angina without electrocardiographic (ECG) changes; class IB, acceleration of previous exertional angina with ECG changes; class II, new-onset exertional angina; class III, new-onset rest angina; class IV, protracted rest angina with ECG changes. The study consisted of 1,387 consecutive patients with unstable angina. Baseline demographics and aggregate in-hospital major cardiac event rates were recorded (myocardial infarction, refractory angina, and death). There was a significant increasing trend in cardiac events from class I to IV (p < 0.0001). Class IA patients had the lowest aggregate event rate at 2.7% (p = 0.0005). Paired chi-square tests of adjacent categories showed no differences in event rates for class IB and II (p = 0.3). A significantly higher rate of adverse events was seen for class III patients (20.1%, p < 0.0001). Class IV patients demonstrated the highest rate of in-hospital adverse events (42.8%, p < 0.0001). We conclude that this easily deduced, universally applicable categorization of unstable angina is highly prognostic of in-hospital adverse cardiac events and hence could have potential use for triage decisions regarding hospital admission and intensity of therapy.     

Long-term results of RITA-1 trial: clinical and cost comparisons of coronary angioplasty and coronary-artery bypass grafting. Randomised Intervention Treatment of Angina

BACKGROUND: Percutaneous transluminal coronary angioplasty (PTCA) and coronary-artery bypass grafting (CABG) are both effective intervention strategies for patients with coronary heart disease. We report comparative long-term clinical and health-service cost findings for these interventions in the first Randomised Intervention Treatment of Angina (RITA-1) trial. METHODS: 1011 patients with coronary heart disease (45% single-vessel, 55% multivessel) were randomly assigned initial treatment strategies of PTCA or CABG. Information on clinical events, subsequent intervention, symptomatic status, exercise testing, and use of health-care resources is available for a median 6.5 years of follow-up. Analyses were by intention to treat. FINDINGS: The predefined primary endpoint of death or nonfatal myocardial infarction occurred in 87 (17%) PTCA-group patients and 80 (16%) CABG-group patients (p=0.64). Similarly, there was no significant treatment difference in deaths alone (39 PTCA, 45 CABG), of which 46% were cardiac related. In both groups, the risk of cardiac death or myocardial infarction was more than five times higher in the first year than in subsequent years of follow-up. 26% of patients assigned PTCA subsequently also had CABG, and a further 19% required additional nonrandomised PTCA. Most of these reinterventions occurred within a year of randomisation, and from 3 years onwards the reintervention rate averaged 4% per year. In the CABG group the reintervention rate averaged 2% per year. The prevalence of angina was consistently higher in the PTCA group, with an absolute average 10% excess compared with the CABG group (p<0.001). Total health-service costs over 5 years showed no significant difference between initial strategies of PTCA and CABG (mean difference pounds sterling 426 [95% Cl -pounds sterling 383 to pounds sterling 1235]; p=0.30). The clinical and cost comparisons showed similar patterns for patients with single-vessel and multivessel disease. INTERPRETATION: Initial strategies of PTCA and CABG led to similar long-term results in terms of survival and avoidance of myocardial infarction and to similar long-term health-care costs. Choice of approach, therefore, rests on weighing the more invasive nature of CABG against the greater risk of recurrent angina and reintervention over many years after PTCA.     

Long-term follow-up of a high risk cohort after stent implantation in saphenous vein grafts

OBJECTIVES: We sought to provide short- and long-term clinical outcomes of a high risk cohort treated with stents in saphenous vein grafts (SVGs). BACKGROUND: Data on the long-term outcome of SVG stenting in high risk patients are limited. METHODS: Johnson & Johnson stents were implanted in the SVGs of 186 patients (302 stents, 244 lesions). Ninety percent of patients presented with myocardial infarction (MI) or unstable angina (mean +/- SD ejection fraction [EF] 44 +/- 11%, patient age 71 +/- 9 years, graft age 9.4 +/- 5 years). Using a risk score classification, 155 patients (83%) were defined as high risk for repeat surgical repair or angioplasty. RESULTS: The procedural success rate was 97.3%, with 2.7% major complications (death, Q wave MI, coronary artery bypass graft surgery [CABG]). Clinical follow-up was obtained in 177 patients (mean 19.1 +/- 13.5 months, range 7 to 59). Event rates were 10% for death; 9% for MI; 11% for repeat CABG; and 15% for repeat angioplasty (total events 45%). Kaplan-Meier estimated survival and event-free survival at 4 years were 0.79 +/- 0.06 and 0.29 +/- 0.07, respectively. Predictors of death were congestive heart failure (p < 0.01) and EF <44% (p < 0.05). Predictors of combined events of death, MI and CABG were low EF (p < 0.01) and high SVG age (>10 years, p < 0.01). There were 66 revascularization procedures (35% of patients), 24% of which were in nontarget lesions. Fifty-three percent of the cardiac events occurred during the first year of follow-up. Of the 160 survivors, 36% were free of angina, 49% were in Canadian Cardiovascular Society functional class I or II, and 15% were in class III or IV. Sixty-nine percent of patients were in class I or II according to the Specific Activity Scale, and 31% of patients were in class III or IV. CONCLUSIONS: Balloon-expandable stent implantation in the SVGs of high risk patients is associated with a low early complication rate. Expected survival rates are good, as are the anginal and functional classifications, but there is a high rate of recurrent events and need for repeat revascularization. Vein graft stenting is an acceptable palliative option in many high risk patients.     

Modeling the electrophoresis of lysozyme. II. Inclusion of ion relaxation

OBJECTIVES: We sought to determine the prognostic value of the admission electrocardiogram (ECG) in patients with unstable angina and non-Q wave myocardial infarction (MI). BACKGROUND: Although the ECG is the most widely used test for evaluating patients with unstable angina and non-Q wave MI, little prospective information is available on its value in predicting outcome in the current era of aggressive medical and interventional therapy. METHODS: ECGs with the qualifying episode of pain were analyzed in patients enrolled in the Thrombolysis in Myocardial Ischemia (TIMI) III Registry, a prospective study of patients admitted to the hospital with unstable angina or non-Q wave MI. RESULTS: New ST segment deviation > or = 1 mm was present in 14.3% of 1,416 enrolled patients, isolated T wave inversion in 21.9% and left bundle branch block (LBBB) in 9.0%. By 1-year follow-up, death or MI occurred in 11% of patients with > or = 1 mm ST segment deviation compared with 6.8% of patients with new, isolated T wave inversion and 8.2% of those with no ECG changes (p < 0.001 when comparing ST with no ST segment deviation). Two other high risk groups were identified: those with only 0.5-mm ST segment deviation and those with LBBB, whose rates of death or MI by 1 year were 16.3% and 22.9%, respectively. On multivariate analysis, ST segment deviation of either > or = 1 mm or > or = 0.5 mm remained independent predictors of death or MI by 1 year. CONCLUSIONS: The admission ECG is very useful in risk stratifying patients with non-Q wave MI. The new criteria of not only > or = 1-mm ST segment deviation but also > or = 0.5-mm ST segment deviation or LBBB identify high risk patients, whereas T wave inversion does not add to the clinical history in predicting outcome.     

Utility of stress single-photon emission computed tomography (SPECT) perfusion imaging in predicting outcome after coronary artery bypass grafting

Previous studies have examined the predictors of outcome in medically treated patients with coronary artery disease (CAD). There is limited information on predictors of outcome after coronary artery bypass grafting (CABG). This study examined the predictors of outcome of 255 patients with CAD, at a mean time of 5 years after CABG for angina pectoris. The 255 patients underwent coronary angiography and stress single-photon emission computed tomography (SPECT) myocardial perfusion imaging after CABG. During a mean follow-up of 41 +/- 28 months after stress testing, there were 34 hard events (24 cardiac deaths and 10 nonfatal myocardial infarctions). The hemodynamics during stress testing, and age and gender were not predictors of events. The SPECT variables of multivessel perfusion abnormality, perfusion deficit size, and increased lung thallium uptake were predictors of death and total events by uni- and multivariate survival analysis. There were 14 events in 45 patients (31%) with multivessel abnormality and increased lung thallium uptake, 14 events in 101 patients (14%) with either multivessel abnormality or increased lung uptake, and 6 events in 109 patients (6%) with neither of these 2 variables (p = 0.0001). The annual mortality and total event rates were 7.5% and 9.5% with both variables, 3.4% and 4.3% with either variable, and 0.6% and 1.7% with neither of the variables (p = 0.01). Thus, stress SPECT perfusion imaging is useful to stratify patients after CABG into low, intermediate, and high risk groups for future cardiac events.     

Vasoactive intestinal peptide and epidermal growth factor: co-mitogens or inhibitors of keratinocyte proliferation in vitro?

Adenosine myocardial perfusion single-photon emission computed tomography (SPECT) is now increasingly used for risk stratification of patients with known or suspected coronary artery disease. However, the incremental prognostic value of this test over clinical and historical information in a large series of women has not been examined. Thus, we studied 923 consecutive women who underwent adenosine technetium (Tc)-99m sestamibi myocardial perfusion SPECT and were followed-up for a mean period of 26+/-8 months. During the follow-up period, 77 hard events (46 cardiac deaths and 31 nonfatal myocardial infarctions) occurred. The results of the perfusion scan significantly risk stratified the population; patients with normal scans had a low rate of nonfatal myocardial infarction and cardiac death (< 1%/year of follow up). Patients with mildly abnormal scans had low cardiac death rates (0.9%/year of follow up); these rates increased as a function of scan abnormality (4.1% and 7.5% mortality per year of follow up in moderate and severely abnormal scans). Cox proportional hazards analysis demonstrated that after adjusting for prior myocardial infarction and diabetes mellitus (the most predictive individual clinical variables [global chi-square=22.5, p <0.001]), as well as heart rate at rest (the most predictive physiologic variable [chi-square=3.8; p=0.05]), the most predictive nuclear variable (summed stress score [chi-square=48.5; p <0.0001]) added significant incremental prognostic information (global chi-square increased from 22.5 to 56.2 [p <0.0001]). In conclusion, adenosine myocardial perfusion SPECT added significant incremental prognostic information to clinical and physiologic variables in women. Normal scans were associated with an excellent prognosis. In contrast, patients with moderately to severely abnormal scans were at a higher risk for future cardiac events.     

Differences in prediction of mortality and non-fatal complications after acute myocardial infarction: a multivariate analysis

The global prognostic after acute myocardial infarction depends of the left ventricular function and the residual ischemia. However, there is controversy about the capacity of some variables reflecting this prognostic factors to predict futures complications. The main objective of this study is to know the influence of the kind of complications in the prognostic value of the variables more frequently used in the clinical practice. We studied 121 consecutive patients with acute myocardial infarction discharged from hospital. The previous and during acute infarction clinical variables were analyzed. The regional and global left ventricular function was studied by 2D echocardiography. An exercise test symptoms-limited was performed at 3rd week after discharge in 94 patients selected. The patients were followed during selected one year. The first year cardiac mortality rate was 8.6%. In the multivariate, the independent predictors of mortality were: age > 60 years (p = 0.02) and the impossibility to perform exercise test (p = 0.0002). In the univariate analysis the echocardiographic motility score > or = 17, eyection fraction < 35% and Killip class > or = II were also death predictors. Non fatal complications (angina, reinfarction o heart failure) were present in 47 patients (42.3%) of 111 survivors. The ischemic complications were predicted in multivariate analysis only by postinfarction angina (p = 0.0007), and heart failure by eyection fraction < 35% (p = 0.006), previous infarct (p = 0.002) and Killip class (p = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)     

Coronary angioplasty versus repeat coronary artery bypass grafting for patients with previous bypass surgery

OBJECTIVES: We attempted to determine the relative risks and benefits of percutaneous transluminal coronary angioplasty (PTCA) and repeat coronary artery bypass grafting (re-CABG) in patients with previous coronary bypass surgery (CABG). BACKGROUND: Due to an expanding population of patients with surgically treated coronary artery disease and the natural progression of atherosclerosis, an increasing number of patients with previous CABG require repeat revascularization procedures. Although there are randomized comparative data for CABG versus medical therapy and, more recently, versus PTCA, these studies have excluded patients with previous CABG. METHODS: We retrospectively analyzed data from 632 patients with previous CABG who required either elective re-CABG (n = 164) or PTCA (n = 468) at a single center during 1987 through 1988. The PTCA and re-CABG groups were similar with respect to gender (83% vs. 85% male), age > 70 years (21% vs. 23%), mean left ventricular ejection fraction (46% vs. 48%), presence of class III or IV angina (70% vs. 63%) and three-vessel coronary artery disease (77% vs. 74%). RESULTS: Complete revascularization was achieved in 38% of patients with PTCA and 92% of those with re-CABG (p < 0.0001). The in-hospital complication rates were significantly lower in the PTCA group: death (0.3% vs. 7.3%, p < 0.0001) and Q wave myocardial infarction (MI) (0.9% vs. 6.1%, p < 0.0001). Actuarial survival was equivalent at 1 year (PTCA 95% vs. re-CABG 91%) and 6 years (PTCA 74% vs. re-CABG 73%) of follow-up (p = 0.32). Both procedures resulted in equivalent event-free survival (freedom from dealth or Q wave MI) and relief of angina; however, the need for repeat percutaneous or surgical revascularization, or both, by 6 years was significantly higher in the PTCA group (PTCA 64% vs. re-CABG 8%, p < 0.0001). Multivariate analysis identified age > 70 years, left ventricular ejection fraction < 40%, unstable angina, number of diseased vessels and diabetes mellitus as independent correlates of mortality for the entire group. CONCLUSIONS: In this nonrandomized series of patients with previous CABG requiring revascularization, an initial stategy of either PTCA or re-CABG resulted in equivalent overall survival, event-free survival and relief of angina. PTCA offers lower procedural morbidity and mortality risks, although it is associated with less complete revascularization and a greater need for subsequent revascularization procedures.     

The 24-hour Tl-201 image in dual isotope myocardial perfusion scintigraphy: clinical utility and prognostic significance

This study assessed the effect on clinical decision making and the possible prognostic significance of the 24-hour Tl-201 image in patients undergoing Tl-201-MIBI dual-isotope myocardial scintigraphy. The records of all patients who underwent 24-hour Tl-201 imaging as part of their myocardial perfusion study from 1994 to 1996 were reviewed. Follow-up evaluations were obtained from the referring physician or by direct patient contact. Fifty-six patients underwent a total of 57 studies; four patients were lost to follow-up. Of the 53 studies evaluated, 29 showed no change between the standard rest images and the 24-hour images; these patients were reported to have myocardial scar. Of these 29 patients, 25 were treated medically without further evaluation; 24 of these 25 patients remained stable. Four of the 29 patients had further evaluation; 2 patients had coronary artery bypass graft, 1 had a stent placed, and 1 remained stable. Twenty-four patients showed definite improvement or normalization of their study results by 24 hours; they were reported as ischemic. Of these 24 patients, 11 were treated medically without further evaluation; 9 remained stable, whereas 2 had adverse events. The remaining 13 patients required further evaluation; 4 remained stable, whereas 9 had adverse events (4 = increasing angina; 1 = stent; 1 = rotoblator; 2 = percutaneous transluminal coronary angioplasty; 1 = death). Twenty-four-hour imaging contributes to clinical decision making and may identify a subset of patients at risk for subsequent complications.     

Immature megakaryocytes undergo apoptosis in the absence of thrombopoietin

OBJECTIVES: We prospectively performed a two-step risk assessment in patients in the early phase after acute myocardial infarction (MI). BACKGROUND: Noninvasive methods like Holter electrocardiographic monitoring (HM) and determination of the left ventricular ejection fraction (EF) as well as the invasive technique of programmed ventricular stimulation (PVS) have been used to identify patients in the late phase after MI as candidates for prophylactic implantation of a cardioverter/defibrillator. However, it is unclear whether these results can be transferred to patients following acute MI. METHODS: A series of 657 patients with acute MI (< or = 75 years) underwent HM and EF. If one of the two methods yielded abnormal findings (HM > or = 20 ventricular ectopic beats/h/> or =10 ventricular pairs/day/ventricular tachycardia; EF < or = 40%), PVS was done (abnormal PVS: induction of monomorphic ventricular tachycardia, duration >10 s, cycle length > or = 230 ms). RESULTS: Of 657 patients, 304 (46%) had either an abnormal HM or EF. The PVS performed in 146 of 304 patients was abnormal in 22. During a mean follow-up of 37 months, there were 106 (16%) deaths, being sudden in 24 (3.6%), nonsudden cardiac in 45 (6.8%). The incidence of arrhythmic events (sudden cardiac death, symptomatic ventricular tachycardia, cardiac arrest) was 18% (4/22) with an abnormal PVS and only 4% (5/124) with a normal PVS (odds ratio 4.0, p=0.032). CONCLUSIONS: The rate of arrhythmic events is low in post-MI patients in the 1990s. Nevertheless, a two-step risk stratification is helpful in selecting candidates for a defibrillator trial aiming at primary prevention of sudden cardiac death after MI.     

Prognostic value of treadmill exercise testing: a population-based study in Olmsted County, Minnesota

BACKGROUND: The prognostic value of treadmill exercise testing (TMET) has been studied in selected populations. The generalizability of these data to different populations and to women is uncertain. METHODS AND RESULTS: A retrospective, population-based cohort study of all persons (1452 men and 741 women) who underwent TMET in years 1987 to 1989 in Olmsted County, Minnesota, was undertaken. Individuals were followed up for all-cause mortality and cardiac events (cardiac deaths, nonfatal myocardial infarction, or congestive heart failure). Sex-specific analyses were performed to determine whether the predictors of outcome and the magnitude of the associations were similar in both sexes. In men, 77 deaths and 106 cardiac events occurred during 8956 person-years of observation; in women, 46 deaths and 54 cardiac events occurred during 4801 person-years of follow-up. Exercise-induced angina, ECG changes, and workload achieved on the TMET were strongly associated with all-cause mortality and cardiac events in both sexes, and the strength of the association was similar. After adjustment, workload was the only TMET variable associated with outcome. A higher workload was associated with a reduction in the risk of cardiac events and of all-cause mortality; the protective effect of exercise capacity was strong and was similar in both sexes. CONCLUSIONS: In this population-based cohort, exercise capacity was the TMET variable that exhibited the strongest association with all-cause mortality and cardiac events. This protective effect of exercise capacity was observed in both sexes.     

Use of exercise technetium-99m sestamibi SPECT imaging to detect residual ischemia and for risk stratification after acute myocardial infarction

The clinical presentation, electrocardiographic findings, and technetium-99m sestamibi single-photon emission computed tomography (SPECT) imaging results of 134 consecutive patients who underwent nuclear exercise testing within 14 days of an acute myocardial infarction (AMI) were correlated with cardiac events over a 15 +/- 10-month follow-up. Whereas only 23 patients (17%) had chest pain and 31 (23%) had ischemic ST-segment depression during exercise, 94 (70%) had ischemia on SPECT (p < 0.001). On follow-up, 13 patients experienced a cardiac event: 7 were rehospitalized for unstable angina, 3 had recurrent AMI, and 3 died of cardiac causes. Ischemia on the sestamibi images identified 11 of these patients (85%), whereas chest pain identified only 3 (23%, p = 0.006), and electrocardiographic ischemia identified only 4 (31%, p = 0.017). The presence of either ischemia as seen on SPECT or defects in multiple vascular territories identified 12 patients (92%) with an event, including all who had cardiac death. By Cox regression analysis of clinical, stress, and image parameters, the number of ischemic defects on SPECT was the only significant correlate of a future event (chi-square = 4.62, p = 0.03), and patients with > or = 3 reversible sestamibi defects had an event rate of 38%. The extent of ischemia as seen on nuclear imaging remained a strong correlate (p = 0.008) of an event in the 54 patients (40%) who had received thrombolytic therapy. Thus, exercise technetium-99m sestamibi SPECT after AMI frequently reveals residual ischemia, and is better than clinical data, symptoms, and stress electrocardiographic data in identifying patients who will have a subsequent cardiac event.     

Incremental prognostic value of adenosine stress myocardial perfusion single-photon emission computed tomography and impact on subsequent management in patients with or suspected of having myocardial ischemia

We examined 1,159 consecutive patients who underwent adenosine stress dual isotope single-photon emission computed tomography (SPECT) and had follow-up performed at a mean of 27.5 +/- 9.1 months (94% complete) for hard events (cardiac death and myocardial infarction) and referral to cardiac catheterization after nuclear testing. During follow-up, 120 hard events occurred (11.0% hard event rate; 72 cardiac deaths [6.7% cardiac death rate] and 57 myocardial infarctions [5.3% myocardial infarction rate]). Cox proportional hazards analysis revealed that nuclear testing added incremental value after adjusting for clinical and historical variables (global chi-square increased 13 to 98 for cardiac death as the end point, global chi-square increased 19 to 105 for hard events as the end point; p <0.0001 for both). Kaplan-Meier analysis demonstrated that after clinical risk stratification of the patient population, the results of nuclear testing were further able to significantly stratify both low- and intermediate- to high-risk patients. Patients with both normal and mildly abnormal scans were at low risk of cardiac death (<1% cardiac death per year of follow-up) and the risk of events increased significantly with worsening scan result. Multivariable analysis revealed that the only predictor of referral to catheterization was the extent and severity of reversible defect present on the scan. Referral rates to early catheterization were very low in patients with normal scans and increased significantly as a function of worsening scan results. In patients who underwent myocardial perfusion SPECT using adenosine stress, the results of nuclear testing yielded incremental prognostic information and clinically relevant risk stratification. Referring physicians predominantly utilized nuclear information when referring patients to catheterization after nuclear testing and do so at rates comparable with those after exercise SPECT despite the higher risk of events in patients undergoing pharmacologic stress.     

Prognostic value of pharmacological stress echocardiography in women with chest pain and unknown coronary artery disease

OBJECTIVES: In this study we sought to investigate the prognostic value of pharmacological stress echocardiography in women referred for chest pain, having unknown coronary artery disease. BACKGROUND: The noninvasive identification of a high-risk subgroup among women with chest pain and unknown coronary artery disease is an unresolved task to date. METHODS: A total of 456 women (mean [+/-SD] age 63+/-10 years) underwent pharmacological stress echocardiography with either dipyridamole (n = 305) or dobutamine (n = 151) for evaluation of chest pain and were followed-up for 32+/-19 months. None of them had a previous diagnosis of coronary artery disease. RESULTS: No major complication occurred during stress testing. Five tests (1.1%) were prematurely interrupted because of the appearance of side effects. Echocardiographic positivity was identified in 51 patients. During the follow-up, 23 cardiac events occurred: 3 deaths, 10 infarctions and 10 cases of unstable angina; an additional 21 patients underwent coronary revascularization. At Cox analysis, the echocardiographic evidence of ischemia was found as the only independent predictor of hard cardiac events (death, infarction) (odds ratio [OR] = 27.5; 95% confidence interval [CI] = (6.5 to 115.5; p = 0.0000). When spontaneous cardiac events (death, infarction and unstable angina) were considered as endpoints, the positive echocardiographic result (OR = 23.9; 95% CI = 8.6 to 66.8; p = 0.0000) and family history of coronary artery disease (OR = 3.7; 95% CI = 1.5 to 9.1; p = 0.0037) were independently correlated with prognosis. By using an interactive stepwise procedure, the prognostic value of stress echocardiography was found to be incremental to that provided by clinical variables, both considering hard and spontaneous cardiac events as endpoints. The 3-year survival rate for the negative and the positive population was respectively, 99.5% and 69.5% (p = 0.0000) considering hard cardiac events, 99.2% and 50.6% (p = 0.0000) considering spontaneous cardiac events. CONCLUSIONS: Pharmacological stress echocardiography is safe, highly feasible and effective in risk stratification of women with chest pain and unknown coronary artery disease, also when hard endpoints are considered. Its use can have relevant implications in daily clinical practice for selection of patients needing further investigations.