Abnormal Q waves on the admission electrocardiogram of patients with first acute myocardial infarction: prognostic implications

BACKGROUND

Q waves developed in the subacute and persisting into the chronic phase of myocardial infarction (MI) usually signify myocardial necrosis. However, the mechanism and significance of Q waves that appear very early in the course of acute MI (< 6 h from onset of symptoms), especially if accompanied by ST elevation, are probably different.

HYPOTHESIS

This study assesses the prognostic implications of abnormal Q waves on admission in 2,370 patients with first acute MI treated with thrombolytic therapy < 6 h of onset of symptoms.

RESULTS

Patients with abnormal Q waves in > or = 2 leads with ST-segment elevation (n = 923) were older than patients without early Q waves (n = 1,447) (60.6 +/- 11.9 vs. 58.8 +/- 11.9 years, respectively; p = 0.0003), and had a greater incidence of hypertension (34.3 vs. 30.5%; p = 0.05) and anterior MI (60.6 vs. 41.1%; p < 0.0001). Time from onset of symptoms to therapy was longer in patients with Q waves upon admission (208 +/- 196 vs. 183 +/- 230 min; p = 0.01). Peak serum creatine kinase (2235 +/- 1544 vs. 1622 +/- 1536 IU; p < 0.0001), prevalence of heart failure during hospitalization (13.8 vs. 7.0%, p < 0.0002), hospital mortality (8.0 vs. 4.6%; p = 0.02), and cardiac mortality (6.6 vs. 4.5%, p = 0.11) were higher in patients with anterior MI and with abnormal Q waves than in those without abnormal Q waves upon admission. There was no difference in peak creatine kinase, prevalence of heart failure, in-hospital mortality, and cardiac mortality between patients with and without abnormal Q waves in inferior MI. Multivariate regression analysis confirmed that mortality is independently associated with presence of Q waves on admission (odds ratio 1.61; 95% CI 1.04-2.49; p = 0.04 for all patients; odds ratio 1.65; 95% CI 0.97-2.83; p = 0.09 for anterior wall MI.

CONCLUSION

Abnormal Q waves on the admission electrocardiogram (ECG) are associated with higher peak creatine kinase, higher prevalence of heart failure, and increased mortality in patients with anterior MI. Abnormal Q waves on the admission ECG of patients with inferior MI are not associated with adverse prognosis.

Comparison of primary coronary angioplasty versus thrombolysis in patients with ST-segment elevation acute myocardial infarction and grade II and grade III myocardial ischemia on the enrollment electrocardiogram

We investigated the impact of primary angioplasty compared with thrombolysis in 894 patients with ST elevation acute myocardial infarction and electrocardiographic grades II and III ischemia on enrollment. Patients were divided into 2 groups based on the enrollment electrocardiogram-grade III: (1) absence of an S wave below the isoelectric baseline in leads that usually have a terminal S configuration (leads V(1) to V(3)), or (2) ST J-point amplitude > or =50% of the R-wave amplitude in all other leads. To be included in the grade III group, grade III criteria in > or =2 adjacent leads were required. Patients with ST elevation but without grade III criteria were classified as having grade II. In-hospital mortality was 3.2% and 6.8% in the grade II (n = 616) and grade III (n = 278) groups, respectively (p = 0.016). In the grade II group, in-hospital mortality was similar in the thrombolysis and angioplasty subgroups (3.2% and 3.3%, p = 0.941). In patients with grade III, in-hospital mortality was 6.4% and 7.3%, respectively (p = 0.762). The odds ratio for the grade III group for death with thrombolysis was 2.06 (95% confidence intervals [CI] 0.82 to 5.19; p = 0.125); the odds ratio for primary angioplasty was 2.30 (95% CI 0.93 to 5.66; p = 0.07). In the thrombolysis group, reinfarction occurred in 3.3% and 6.5% of the grade II and grade III subgroups (p = 0.137). In the angioplasty group, reinfarction occurred in 1.3% and 4.4%, respectively (p = 0.239). Grade III ischemia on admission was associated with higher in-hospital and 30-day mortality and a higher rate of reinfarction. There was no difference in mortality between primary angioplasty and thrombolysis in the grade II and grade III ischemia patients.

Early reinfarction after fibrinolysis: experience from the global utilization of streptokinase and tissue plasminogen activator (alteplase) for occluded coronary arteries (GUSTO I) and global use of strategies to open occluded coronary arteries (GUSTO III) trials

BACKGROUND

Trials report a 2% to 6% incidence of reinfarction after fibrinolysis for acute myocardial infarction (MI). We combined the Global Utilization of Streptokinase and Tissue plasminogen activator (alteplase) for Occluded coronary arteries (GUSTO I) and Global Use of Strategies To Open occluded coronary arteries (GUSTO III) populations to better define frequency, timing, and clinical predictors of in-hospital reinfarction.

METHODS AND RESULTS

In 55 911 patients with ST-segment elevation myocardial infarction (MI) who were receiving fibrinolysis, we compared baseline characteristics and mortality rate by reinfarction incidence and developed multivariable logistic regression models to predict in-hospital reinfarction and composite of death or reinfarction. Reinfarction occurred in 2258 patients (4.3%) a median of 3.8 days after fibrinolysis; rates did not differ between GUSTO I (4.0%) and GUSTO III (4.2%) or by fibrinolytic assignment (streptokinase, 4.1%; alteplase, 4.3%; reteplase, 4.5%; combined streptokinase and alteplase, 4.4%; P=0.55). Advanced age, shorter time to fibrinolysis, non-US enrollment, nonsmoking status, prior MI or angina, female sex, anterior MI, and lower systolic blood pressure were associated significantly with reinfarction. Patients with reinfarction had higher mortality at 30 days (11.3% versus 3.5% without reinfarction; odds ratio, 3.5; P<0.001) and from 30 days to 1 year (4.7% versus 3.2%; hazard ratio, 1.5; P<0.001). Significant multivariate predictors of in-hospital death or reinfarction included age, Killip class, systolic and diastolic blood pressures, heart rate, anterior MI, smoking status, prior MI, sex, and country of enrollment (all P<0.001).

CONCLUSIONS

Reinfarction occurs infrequently after fibrinolysis but confers increased risk of 30-day and 1-year mortality. Some predictors of reinfarction differ from known predictors of death after MI. Improved treatment and prevention strategies for reinfarction deserve study.

Prediction of the extent and severity of left ventricular dysfunction in anterior acute myocardial infarction by the admission electrocardiogram

BACKGROUND

The grade of ischemia, as detected by the relation between the QRS complex and ST segment on the admission electrocardiogram, is associated with larger infarct size and increased mortality rates in acute myocardial infarction.

METHODS

We assessed the correlation between left ventricular function and the admission electrocardiogram in 151 patients with first anterior acute myocardial infarction who received thrombolytic therapy and underwent cardiac catheterization at 90 minutes and before hospital discharge. The number of leads with ST elevation, sum of ST elevation, maximal Selvester score, and the presence of severe (grade 3) ischemia were determined in each electrocardiogram. Left ventricular ejection fraction, the number of chords with wall motion abnormalities, and the severity of dysfunction (SD/chord) were determined.

RESULTS

At 90 minutes, the 39 ischemia grade 3 patients had lower ejection fraction than the 112 grade 2 patients. Both at 90 minutes and at hospital discharge, the grade 3 group had more chords with wall motion abnormalities and more severe regional dysfunction (SD/chord). However, the number of leads with ST elevation, sum of ST elevation, and maximal Selvester score had no correlation with ejection fraction at 90 minutes and only mild correlation with the extent of dysfunction (number of chords) at 90 minutes. There was no correlation between either the number of leads with ST elevation or the sum of ST elevation and the severity of regional dysfunction.

CONCLUSIONS

The number of leads with ST elevation, sum of ST elevation, and maximal Selvester score had only mild correlation with the extent of myocardial dysfunction but not with the severity of dysfunction. Grade 3 ischemia is predictive of more extensive myocardial involvement and greater severity of regional dysfunction.

Treatment of reinfarction after thrombolytic therapy for acute myocardial infarction: an analysis of outcome and treatment choices in the global utilization of streptokinase and tissue plasminogen activator for occluded coronary arteries (gusto I) and assessment of the safety of a new thrombolytic (assent 2) studies

BACKGROUND

Early reinfarction after thrombolytic therapy is associated with adverse outcomes and increased mortality. Among patients with reinfarction in the 1992 Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO I) and the 1998 Assessment of the Safety of a New Thrombolytic (ASSENT 2) trials, we investigated temporal and regional differences in the use of repeat thrombolysis, revascularization (angioplasty and/or bypass surgery), or conservative measures and the outcomes of each management strategy.

METHODS AND RESULTS

Data from the 4% of patients (n=2301) who experienced reinfarction after thrombolytic therapy were studied. Baseline characteristics, 30-day mortality, and incidence of total and hemorrhagic strokes were compared among the 3 treatment groups. The 30-day mortality did not differ between the repeat thrombolysis and revascularization groups (P=0.72), and it was significantly lower among patients treated by these 2 strategies than in those treated conservatively (11% and 11% versus 28%, respectively; P<0.001). Stroke rates did not differ significantly between the 3 treatment strategies (P=0.49). From 1992 to 1998, the percentage of reinfarction patients treated with repeat thrombolysis decreased from 29.3% to 18.5% in US centers and from 51.4% to 41.9% in all other centers (P<0.001). In contrast, use of revascularization procedures increased from 33.5% to 47.9% in US centers and from 8.1% to 23.0% in all other centers (P<0.001).

CONCLUSIONS

Repeat thrombolysis and revascularization are associated with significantly lower mortality among reinfarction patients. Randomized trials are necessary to assess the exact risks and benefits of rethrombolysis versus interventional revascularization in this subset of high-risk patients presenting with reinfarction after thrombolytic therapy.

Clinical and electrocardiographic variables associated with increased risk of ventricular septal defect in acute anterior myocardial infarction

It is unknown whether the risk factors associated with the development of ventricular septal defect (VSD) after acute myocardial infarction (MI) remain the same when thrombolytic therapy is used, nor have specific electrocardiographic patterns of acute MI associated with the development of VSD been identified. Our study population included patients with an anterior MI enrolled in the GUSTO-I study. Baseline clinical data were collected prospectively for all patients. Patients in whom VSD was suspected by the local investigators at each site were evaluated retrospectively. Baseline clinical and electrocardiographic variables were compared between 2 groups: 10,847 patients without VSD (99.6%) and 48 patients with confirmed VSD (0.4%). Multivariate analysis showed the following clinical variables to be independent predictors of VSD: age (odds ratio [OR] 2.19, 95% confidence intervals [CI] 1.62 to 2.98; p <0.001), female gender (OR 5.07, 95% CI 2.70 to 9.98; p <0.001), and lack of previous angina (OR 2.11, 95% CI 1.12 to 4.29; p = 0.021). Two electrocardiographic variables predicted acute VSD: the magnitude of ST deviation in lead III (OR 1.55, 95% CI 1.12 to 2.21; p = 0.007) and in lead V(2) (p <0.001). However, the relation between the ST amplitude in lead V(2) and the risk for VSD was nonlinear. In patients with anterior MI who underwent thrombolysis, the risk factors for VSD were age, female gender, and lack of previous angina. Previous infarction was not a risk factor. Less ST-segment depression in lead III was a predictor of VSD.

The prognostic implications of negative T waves in the leads with ST segment elevation on admission in acute myocardial infarction

We assessed the prognostic significance of negative T waves on admission in leads with ST elevation in 2,853 patients with acute myocardial infarction treated with thrombolysis. Patients were classified into 2 groups based on the presence of negative (T-) or positive (T+) T waves in the leads with ST elevation on admission. T+ and T- waves on admission were detected in 2,601 (91%) and 252 (9%) patients, respectively. T- waves were observed in 6.7 and 9.6% of patients admitted </=2 and 2-6 h after onset of infarction, respectively. There was a difference in prognosis between patients admitted </=2 and >2 h after symptom onset. T- patients admitted </=2 h after onset had no hospital mortality (0/52 patients), as compared to a 5.0% mortality rate in T+ patients (36/726 patients; p = 0.19). T- patients treated >2 h after onset suffered higher mortality (20/196 patients; 10.2%) than T+ patients (100/1,836 patients; 5.4%; p = 0.01). Multivariate analysis of the data on patients treated >2 h after onset demonstrated T- waves to be associated with mortality (OR 1.86; 95% CI 1.07-3.25; p = 0.017). T- waves in leads with ST elevation upon admission are associated with adverse prognosis in patients presenting >2 h after symptom onset, whereas in patients presenting </=2 h after first symptoms, T- waves may be associated with better prognosis.

Neurosurgical evacuation of intracranial hemorrhage after thrombolytic therapy for acute myocardial infarction: experience from the GUSTO-I trial. Global Utilization of Streptokinase and tissue-plasminogen activator (tPA) for Occluded Coronary Arteries

BACKGROUND

Intracranial hemorrhage is an uncommon but very dangerous complication in patients receiving thrombolytic therapy for acute myocardial infarction. Neurosurgical evacuation is often an available treatment option. However, the association between neurosurgical evacuation and clinical outcomes in these patients has yet to be determined.

METHODS

The GUSTO-I trial randomly assigned 41,021 patients with acute myocardial infarction to 1 of 4 thrombolytic strategies in 1081 hospitals in 15 countries. A total of 268 patients (0.65%) had an intracranial hemorrhage. We assessed differences in clinical characteristics, neuroimaging features, Glasgow coma scale scores, functional status (disabled: moderate or severe deficit; not disabled: no or minor deficit) and 30-day mortality rate between the 46 patients who underwent neurosurgical evacuation and the 222 patients who did not.

RESULTS

Mortality rate at 30 days for all patients with intracranial hemorrhage was 60%; an additional 27% were disabled. Evacuation was associated with significantly higher 30-day survival (65% versus 35%, P <.001) and a trend toward improved functional status (nondisabling stroke: 20% versus 12%, P =.15).

CONCLUSIONS

Although intracranial hemorrhage is uncommon after thrombolysis for acute myocardial infarction, 87% of patients die or have disabling stroke. Although not definitive, these data indicate that neurosurgical evacuation may be associated with improved clinical outcomes. Physicians treating such patients should consider early neurosurgical consultation and intervention in these patients.

Correlation of angiographic findings and right (V1 to V3) versus left (V4 to V6) precordial ST-segment depression in inferior wall acute myocardial infarction

This study assessed whether differences in the underlying mechanisms for various patterns of precordial ST-segment depression with inferior acute myocardial infarction (AMI) are associated with poorer prognoses. We studied 1,155 patients with inferior AMI who underwent thrombolysis in the Global Utilization of Streptokinase and TPA for Occluded arteries (GUSTO-I) angiographic substudy: those without precordial ST depression (n = 412; 35.7%), those with maximum ST depression in leads V1 to V3 (n = 547; 47.4%), and those with maximum ST depression in leads V4 to V6 (n = 196; 17.0%) on admission electrocardiogram. We compared the infarct-related artery, presence of left anterior descending or multivessel coronary artery disease, and left ventricular function among groups. Patients with maximum ST depression in leads V4 to V6 more often had 3-vessel disease (26.0%) than those without precordial ST depression (13.5%) or those with ST depression in leads V1 to V3 (15.7%; p = 0.002), and they had a lower ejection fraction (median 54% vs 60% and 55%, respectively; p <0.001). Patients with maximum ST depression in leads V1 to V3 less often had AMIs due to proximal right coronary artery obstruction (23.9%) than patients without precordial ST depression (35.2%) or those with ST depression in leads V4 to V6 (40.0%; p = 0.001) and had larger AMIs as estimated by peak creatine kinase. Different patterns of precordial ST depression are associated with distinctive coronary anatomy. ST depression in leads V4 to V6, but not V1 to V3, confers a greater likelihood of multivessel coronary artery disease.

Admission clinical and electrocardiographic characteristics predicting an increased risk for early reinfarction after thrombolytic therapy

BACKGROUND

This study assessed the ability of clinical and electrocardiographic variables routinely obtained on admission to identify patients with acute myocardial infarction treated with thrombolytic therapy at risk of early reinfarction.

METHODS AND RESULTS

The study included 2602 patients who received thrombolytic therapy for acute myocardial infarction. Baseline demographic variables and admission clinical and electrocardiographic variables were compared between patients with and without reinfarction. Multivariable logistic regression technique was used and included recurrent infarction as the dependent variable, and baseline demographic, clinical, and electrocardiographic variables as independent variables. History of hypertension (odds ratio [OR] 1.52, 95% confidence interval [CI] 1.00 to 2.31) and diabetes mellitus (OR 1.59, 95% CI 1.00 to 2.53) were associated with a higher risk, and current smoking was associated with a lower risk (OR [no versus yes] 1.64, 95% CI 1.05 to 2.58) of early hospital reinfarction. Distortion of the terminal portion of the QRS complex (OR 1.86, 95% CI 1.20 to 2.87) and absence of abnormal Q waves on admission (OR 1.54, 95% CI 0.98 to 2.43) were associated with increased risk of early reinfarction.

CONCLUSIONS

A simple electrocardiographic sign is a reliable predictor of early reinfarction among patients who receive thrombolytic therapy for acute myocardial infarction.

Risk factors for in-hospital nonhemorrhagic stroke in patients with acute myocardial infarction treated with thrombolysis: results from GUSTO-I

BACKGROUND

Nonhemorrhagic stroke occurs in 0.1% to 1.3% of patients with acute myocardial infarction who are treated with thrombolysis, with substantial associated mortality and morbidity. Little is known about the risk factors for its occurrence.

METHODS AND RESULTS

We studied the 247 patients with nonhemorrhagic stroke who were randomly assigned to one of four thrombolytic regimens within 6 hours of symptom onset in the GUSTO-I trial. We assessed the univariable and multivariable baseline risk factors for nonhemorrhagic stroke and created a scoring nomogram from the baseline multivariable modeling. We used time-dependent Cox modeling to determine multivariable in-hospital predictors of nonhemorrhagic stroke. Baseline and in-hospital predictors were then combined to determine the overall predictors of nonhemorrhagic stroke. Of the 247 patients, 42 (17%) died and another 98 (40%) were disabled by 30-day follow-up. Older age was the most important baseline clinical predictor of nonhemorrhagic stroke, followed by higher heart rate, history of stroke or transient ischemic attack, diabetes, previous angina, and history of hypertension. These factors remained statistically significant predictors in the combined model, along with worse Killip class, coronary angiography, bypass surgery, and atrial fibrillation/flutter.

CONCLUSIONS

Nonhemorrhagic stroke is a serious event in patients with acute myocardial infarction who are treated with thrombolytic, antithrombin, and antiplatelet therapy. We developed a simple nomogram that can predict the risk of nonhemorrhagic stroke on the basis of baseline clinical characteristics. Prophylactic anticoagulation may be an important treatment strategy for patients with high probability for nonhemorrhagic stroke, but further study is needed.

Diabetic retinopathy should not be a contraindication to thrombolytic therapy for acute myocardial infarction: review of ocular hemorrhage incidence and location in the GUSTO-I trial. Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries

OBJECTIVES

This study sought to evaluate the incidence of ocular hemorrhage in patients with and without diabetes after thrombolytic therapy for acute myocardial infarction.

BACKGROUND

Ocular hemorrhage after thrombolysis has been reported rarely. However, there is concern that the risk is increased in patients with diabetes. In fact, diabetic hemorrhagic retinopathy has been identified as a contraindication to thrombolytic therapy without clear evidence that these patients have an increased risk for ocular hemorrhage.

METHODS

We identified all suspected ocular hemorrhages from bleeding complications reported in patients enrolled in the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO)-I trial. Additional information was collected on a one-page data form. We compared the incidence and location of ocular hemorrhages in patients with and without diabetes.

RESULTS

There were 40,899 patients (99.7%) with information about diabetic history and ocular bleeding. Twelve patients (0.03%) had an ocular hemorrhage. Intraocular hemorrhage was confirmed in only one patient. There were 6,011 patients (15%) with diabetes, of whom only 1 had an ocular hemorrhage (eyelid hematoma after a documented fall). The upper 95% confidence intervals for the incidence of intraocular hemorrhage in patients with and without diabetes were 0.05% and 0.006%, respectively.

CONCLUSIONS

Ocular hemorrhage and, more important, intraocular hemorrhage after thrombolytic therapy for acute myocardial infarction is extremely uncommon. The calculated upper 95% confidence interval for the incidence of intraocular hemorrhage in patients with diabetes was only 0.05%. We conclude that diabetic retinopathy should not be considered a contraindication to thrombolysis in patients with an acute myocardial infarction.

Admission clinical and electrocardiographic characteristics predicting in-hospital development of high-degree atrioventricular block in inferior wall acute myocardial infarction

This study assessed the ability of simple clinical and electrocardiographic variables routinely obtained on admission to identify patients who are at high risk of developing high-degree atrioventricular (AV) block during hospitalization in 1,336 patients with inferior wall acute myocardial infarction (AMI). Patients were classified into 2 initial electrocardiographic patterns based on the J-point to R-wave amplitude ratio: pattern 1: those with J point/R wave <0.5 and pattern 2: patients with J point/R wave > or =0.5 in > or =2 leads of the inferior leads II, III, and aVF. High-degree AV block was found in 6.7% of patients (41 of 615) with pattern 1 versus 11.8% of the patients (85 of 721) with pattern 2 on admission electrocardiogram (p = 0.0008). Multivariate logistic regression analysis revealed that the only variables found to be independently associated with high-degree AV block were female gender (odds ratio [OR] 1.48; 95% confidence interval [CI] 0.98 to 2.23; p = 0.06); Killip class on admission > or =2 (OR 2.24; CI 1.43 to 3.51; p = 0.0004); initial electrocardiographic pattern 2 versus pattern 1 (OR 1.82; CI 1.22 to 2.21; p = 0.003); and absence of abnormal Q waves on admission (OR yes vs no 0.68; CI 0.44 to 1.05; p = 0.08). A simple electrocardiographic sign (J point/R wave > or =0.5 in > or =2 leads) is a reliable predictor of the development of advanced AV block among patients receiving thrombolytic therapy for inferior wall AMI.

Selection of thrombolytic therapy for individual patients: development of a clinical model. GUSTO-I Investigators

We developed a logistic regression model with data from the GUSTO-I trial to predict mortality rate differences in individual patients who received accelerated tissue plasminogen activator (TPA) versus streptokinase treatment for acute myocardial infarction. A nomogram was developed from a reduced version of this model that approximated the underlying risk of patients treated with streptokinase, and thus the benefit of TPA. The 30-day mortality rate with accelerated TPA was 0.063 versus 0.073 with streptokinase and subcutaneously administered heparin and 0.074 with streptokinase and intravenously administered heparin. No baseline patient characteristics were significantly associated with a different relative effect of TPA. Older patients and those with anterior infarction, higher Killip classification (except Killip class IV), lower blood pressure, and increased heart rate had the greatest absolute benefit with accelerated TPA. Patients with acute myocardial infarction who had more high-risk characteristics derived a greater absolute benefit from treatment with accelerated TPA versus streptokinase.

Age and outcome with contemporary thrombolytic therapy. Results from the GUSTO-I trial. Global Utilization of Streptokinase and TPA for Occluded coronary arteries trial

BACKGROUND

Elderly patients with acute myocardial infarction have much to gain from reperfusion with thrombolytic therapy but are also at increased risk of adverse events. We examined outcomes according to age of patients receiving thrombolysis in an international trial.

METHODS AND RESULTS

Patients were randomized to streptokinase plus subcutaneous heparin, streptokinase plus intravenous heparin, accelerated tissue plasminogen activator (TPA) plus intravenous heparin, or streptokinase and TPA plus intravenous heparin. Clinical outcomes at 30 days (death, stroke, and nonfatal, disabling stroke) and 1-year mortality were summarized descriptively for patients aged < 65 (n = 24,708), 65 to 74 (n = 11,201), 75 to 85 (n = 4625), and > 85 years (n = 412) and assessed as continuous functions of age. Older patients had a higher-risk profile with regard to baseline clinical and angiographic characteristics. Mortality at 30 days increased markedly with age (3.0%, 9.5%, 19.6%, and 30.3% in the four groups, respectively), as did stroke, cardiogenic shock, bleeding, and reinfarction. Combined death or disabling stroke occurred less often with accelerated TPA in all but the oldest patients, who showed a weak trend toward a lower incidence with streptokinase plus subcutaneous heparin: odds ratio 1.13; 95% confidence interval 0.6, 2.1. Similarly, accelerated TPA treatment resulted in lower 1-year mortality in all but the oldest patients (47% TPA versus 40.3% streptokinase).

CONCLUSIONS

Lower mortality and greater net clinical benefit were seen with accelerated TPA in patients aged < or = 85 years. Because data are limited for patients aged > 85 years, the relative superiority of a given thrombolytic regimen cannot be determined. The interactions of stroke and mortality with newer thrombolytic strategies must be examined explicitly in older patients.

Prognostic significance of precordial ST segment depression on admission electrocardiogram in patients with inferior wall myocardial infarction

OBJECTIVES

This study assessed retrospectively the correlation between the pattern of precordial ST segment depression on the admission electrocardiogram (ECG) and hospital mortality in patients with an inferior myocardial infarction treated with intravenous thrombolytic therapy.

BACKGROUND

Previous studies have shown that in acute inferior myocardial infarction, ST segment depression in the precordial leads is associated with increased hospital mortality. However, the significance of the different patterns of precordial ST segment depression has been evaluated in only two previous studies.

METHODS

The study included 1,321 patients (1,020 men) who enrolled in the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO-I) trial in Israel and received intravenous thrombolytic therapy. Patients with an ST segment elevation > or = 0.1 mV in at least two of the inferior leads were included. Patients were classified into four groups on the basis of their admission ECG: group I = patients with no precordial ST segment depression (n = 346); group II = those for whom the sum of ST segment depression in leads V1 to V3 was greater than that in leads V4 to V6 (n = 700); group III = those for whom the sum of ST depression in leads V1 to V3 was equal to that in leads V4 to V6 (n = 162); group IV = those with maximal ST depression in leads V4 to V6 (n = 113).

RESULTS

The overall hospital mortality rate was 3.6% (48 patients): for groups I, II, III and IV it was 2.9%, 2.8%, 4.3% and 9.7%, respectively. Multivariable logistic regression analysis confirmed that hospital mortality was independently associated with the pattern of precordial ST segment depression. The odd ratios in group IV relative to group I was 2.78 (95% confidence interval 1.26 to 6.13, p = 0.007).

CONCLUSIONS

The risk of mortality is higher in patients with an inferior myocardial infarction and maximal ST segment depression in precordial leads V4 to V6 versus precordial leads V1 to V3 on the admission ECG.

Prognostic significance of the admission electrocardiogram in acute myocardial infarction

OBJECTIONS

We sought to access the ST segment and the terminal portion of the QRS complex in the initial electrocardiogram (ECG) as tools to predict outcome in patients with acute myocardial infarction given thrombolytic therapy.

BACKGROUND

Previous studies assessing early risk stratification of patients with acute myocardial infarction by ECG criteria have focused on the number of leads with ST segment elevation or the absolute magnitude of ST deviation. A new classification independent of the absolute values of ST deviation was pursued.

METHODS

Patients with ST elevation and positive T waves in at least two adjacent leads who received thrombolytic therapy were classified into two groups based on the absence (1,232 patients) or presence (1,371 patients) of distortion of the terminal portion of the QRS complex on the admission ECG.

RESULTS

There were no differences between groups in the prevalence of previous angina, hypertension, current smoking, anterior infarction, time from onset of symptoms to therapy of type of thrombolytic regimen. Patients with QRS distortion were less likely to have had a previous infarction (12.0% vs. 18.4%, p = 0.02) or diabetes mellitus (16.9% vs. 21.4%, p = 0.003). They had higher peak creatine kinase levels (1,617 +/- 1,670 vs. 1,080 +/- 1,343 IU, p = 0.00001). Hospital mortality for those with and without QRS distortion was 6.8% and 3.8%, respectively (p = 0.0008). Multivariable logistic regression analysis confirmed that hospital mortality was independently associated with distortion of terminal portion of the QRS complex (odds ratio 1.78, 95% confidence interval 1.19 to 2.68, p = 0.004).

CONCLUSIONS

Distortion of the terminal portion of the QRS complex on the admission ECG is independently associated with a higher hospital mortality rate in patients with acute myocardial infarction given thrombolytic therapy.

Comparisons of characteristics and outcomes among women and men with acute myocardial infarction treated with thrombolytic therapy. GUSTO-I investigators

OBJECTIVE

To compare baseline characteristics, complications, and treatment-specific outcomes of women and men with acute myocardial infarction treated with thrombolytic therapy.

DESIGN

Randomized controlled trial.

PATIENTS AND SETTING

A total of 10315 women and 30706 men with acute myocardial infarction treated in 1081 hospitals in 15 countries as part of the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I).

INTERVENTION

One of four thrombolytic regimens: (1) streptokinase with subcutaneous heparin; (2) streptokinase with intravenous heparin; (3) streptokinase plus alteplase (tissue-type plasminogen activator) with intravenous heparin; or (4) accelerated alteplase with intravenous heparin.

MAIN OUTCOME MEASURES

Mortality, stroke, and nonfatal complications during 30-day follow-up.

RESULTS

Women were on average 7 years older than men and delayed 18 minutes (median) longer after symptom onset before presenting to the hospital. After adjustment for age, women more often had a history of diabetes, hypertension, and smoking than men. Time to treatment was significantly longer in women (1.2 vs 1.0 hours; P<.001). Women had more nonfatal complications after treatment, including shock (9% vs 5%; P<.001), congestive heart failure (22% vs 14%; P<.001), serious bleeding (15% vs 7%; P<.001), and reinfarction (5.1% vs 3.6%; P<.001). Women had twice as many total strokes as men (2.1% vs 1.2%; P<.001), secondary to their older age at presentation. The unadjusted mortality rate was twice as high in women as men (11.3% vs 5.5%; P<.001); the relative risk (RR) of death was greater among women than men after adjustment for differences in baseline characteristics (RR=1.15; 95% confidence interval, 1.0 to 1.31). Although women and men underwent angiography at similar rates, there were small but significant differences in their rates of revascularization procedures (angioplasty: 35% of women and 32% of men; bypass surgery: 7% of women and 9% of men; P<.001 for both). The higher rate of stroke in women after treatment with alteplase (2.0% vs 1.9% with streptokinase and intravenous heparin) was offset by a greater relative reduction in mortality (10.3% vs 11.1%).

CONCLUSION

Women who received thrombolytic therapy for treatment of acute myocardial infarction were at greater risk for both fatal and nonfatal complications than men.

Stroke after thrombolysis. Mortality and functional outcomes in the GUSTO-I trial. Global Use of Strategies to Open Occluded Coronary Arteries

BACKGROUND

Stroke is the most feared complication of thrombolysis for acute myocardial infarction because of the resulting mortality and disability. We analyzed the incidence, timing, and outcomes of stroke in an international trial.

METHODS AND RESULTS

Patients were randomly assigned to one of four thrombolytic strategies. Neurological events were confirmed clinically and anatomically and were adjudicated by a blinded committee. Stroke survivors, categorized by residual deficit and disability, assessed their quality of life with a time trade-off technique. Multivariable regression identified patient characteristics associated with intracranial hemorrhage. Over-all, 1.4% of the patients had a stroke (93% anatomic documentation). The risk ranged from 1.19% with streptokinase/subcutaneous heparin therapy to 1.64% with combination thrombolytic therapy (P = .007). Primary intracranial hemorrhage rates ranged from 0.46% with streptokinase/subcutaneous heparin to 0.88% with combination therapy (P < .001). Of all strokes, 41% were fatal, 31% were disabling, and 24% were nondisabling, with no significant treatment-related differences. Stroke subtype affected prognosis: 60% of patients with primary intracranial hemorrhage died and 25% were disabled versus 17% dead and 40% disabled with nonhemorrhagic infarctions. Patients with moderate or severe residual deficits showed significantly decreased quality of life. Advanced age, lower weight, prior cerebrovascular disease or hypertension, systolic and diastolic blood pressures, randomization to tissue plasminogen activator, and an interaction between age and hypertension were significant predictors of intracranial hemorrhage.

CONCLUSIONS

Stroke remains a rare but catastrophic complication of thrombolysis. Additional studies should assess the net clinical benefit of thrombolysis in high-risk subgroups, particularly the elderly and patients with prior cerebrovascular events.

Evaluation of paradoxic beneficial effects of smoking in patients receiving thrombolytic therapy for acute myocardial infarction: mechanism of the "smoker's paradox" from the GUSTO-I trial, with angiographic insights. Global Utilization of Streptokinase and Tissue-Plasminogen Activator for Occluded Coronary Arteries

OBJECTIVES

Our purpose was to evaluate the relation between smoking and the outcomes of patients receiving thrombolysis for acute myocardial infarction.

BACKGROUND

A paradoxic beneficial effect has been observed in smokers with a myocardial infarction. We analyzed outcomes and baseline characteristics of 11,975 nonsmokers, 11,117 ex-smokers and 17,507 current smokers in a multinational trial of thrombolysis for acute myocardial infarction.

METHODS

Patients were randomized to one of four thrombolytic protocols. An angiographic substudy in 2,431 patients evaluated reperfusion, reocclusion and ventricular function. Effects of smoking were evaluated by logistic regression analysis after adjustment for age and gender. A mortality model evaluated the simultaneous effect of baseline characteristics on the prognostic importance of smoking. These processes were performed with data from both the main trial and the angiographic substudy; then angiographic factors (coronary anatomy, patency and ejection fraction) were added to the model.

RESULTS

Smokers were significantly younger by a mean of 11 years) and had less comorbidity or severe coronary artery disease than nonsmokers. Nonsmokers had significantly higher hospital and 30-day mortality rates (9.9% and 10.3%, respectively) than smokers (3.7% vs. 4%, respectively, both p < 0.001) and more in-hospital complications. The unadjusted odds ratio for 30-day mortality in nonsmokers was 3.36 (95% confidence interval [CI] 2.08 to 5.41), 1.21 (95% CI 0.71 to 2.08) after adjustment for age and gender and 1.08 (95% CI 0.59 to 1.96) after adjustment for all clinical baseline characteristics.

CONCLUSIONS

Smokers receiving thrombolysis for acute myocardial infarction presented 11 years earlier than nonsmokers, which generally accounted for their better outcome. When other differences in clinical and angiographic baseline factors and therapeutic responses were evaluated, no significant difference in mortality was seen between smokers and nonsmokers.

Variations in patient management and outcomes for acute myocardial infarction in the United States and other countries. Results from the GUSTO trial. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries

OBJECTIVE

To examine differences in outcomes and patient management between patients in the United States and outside the United States undergoing thrombolysis for acute myocardial infarction.

DESIGN, SETTING, AND PATIENTS

Patients in the United States (n = 23,105) and 14 other countries (n = 17,916) were randomized to receive streptokinase plus either subcutaneous or intravenous (IV) heparin, accelerated recombinant tissue-type plasminogen activator (rt-PA) plus IV heparin, or combined streptokinase and rt-PA plus IV heparin.

OUTCOME MEASURES

Differences in 30-day mortality and patient management were compared among treatments and between US and non-US patients. Treatment-by-country interactions were assessed by logistic regression analyses. Expected mortality of US and non-US patients was estimated using a predictive model and was compared with observed mortality.

RESULTS

Mortality reduction with accelerated rt-PA vs streptokinase was greater in the United States (1.2% absolute decrease vs 0.7% elsewhere), but the test for treatment-by-country interaction against streptokinase was not significant (P = .30). Benefits of accelerated rt-PA over combination therapy were observed in the United States, but not in other countries (P = .02). Despite differences in base-line characteristics and patient management, 30-day mortality was not significantly different: 6.8% in the United States vs 7.2% elsewhere (P = .09). After adjustment for baseline differences, observed vs predicted outcomes were slightly better in the United States (6.8% vs 7.0%) than elsewhere (7.2% vs 7.0%), indicating that enrollment in the United States was a marginally significant predictor of better survival (P = .047).

CONCLUSIONS

No significant evidence for a differentially greater benefit of accelerated rt-PA over streptokinase was found in US vs non-US patients. However, increased procedure and treatment use in the United States was associated with only a small decrease in short-term mortality. Long-term follow-up is required to clarify the relationship between survival and the more intensive US management approach.

Acute myocardial infarction in the young--the role of smoking. The Investigators of the International Tissue Plasminogen Activator/Streptokinase Mortality Trial

Patients who received thrombolytic therapy for acute myocardial infarction in a large international trial were divided into two groups on the basis of age; those < or = 40 years (n = 269) and those > 40 years (n = 7787). The younger group included more men (89.9% vs 75.9%, P = 0.009) and fewer patients had a history of coronary artery disease, hypertension, and diabetes mellitus. A family history of cardiovascular disease was significantly more prevalent among the young patients (53.4% vs 41.9%, P = 0.0002). Significantly more younger patients than older patients were smokers at the time of infarction (76.2% vs 42.9%, P < 0.0001) and the average number of cigarettes smoked per day was also significantly higher in young patients (27.8 +/- 14.3 vs 19.9 +/- 12.9, P < 0.01). Younger patients had a better outcome, with lower rates of cardiogenic shock (1.1% vs 7.0%, P = 0.0002), stroke (0.0% vs 1.9%, P = 0.02) and haemorrhage (1.9% vs 5.9%, P = 0.006), as well as a better Killip class at discharge (Killip > 1 in 4.5% vs 8.0%, P < 0.001), and lower hospital and 6-month mortality (0.7% and 3.1% vs 8.3% and 12%, P < 0.001, respectively). The better outcome of younger patients with acute myocardial infarction is related to their better baseline characteristics. Young patients with acute myocardial infarction have a strong family history of cardiovascular disease and a high prevalence of smoking. Smoking is the most important modifiable risk factor in these patients.

Improved survival of hospitalized patients with acute myocardial infarction from 1981-1983 to 1992 in Israel. The SPRINT Study Group and The Israeli Thrombolytic Survey Group. Secondary Prevention Israeli Nifedipine Trial

BACKGROUND

This study compares in-hospital and 1-year mortality rates in two large cohorts of patients with acute myocardial infarction (AMI) who were admitted to coronary care units in Israel in 1981-1983 and in 1992. Since the late 1960s and early 1970s there has been a remarkable decline in mortality from cardiovascular causes in most Western countries; the reason for this decline is not completely understood. Although several studies have shown a significant decrease in in-hospital mortality from AMI between the 1960s and the 1980s, studies comparing survival after AMI between the 1980s and 1990s are relatively scarce. Over the past decade important medical treatments and procedures for the management of AMI were introduced.

METHODS

Between August 1981 and July 1983, 5839 consecutive patients were admitted to 13 coronary care units in Israel with a confirmed diagnosis of AMI. Demographic and medical data from hospital charts were recorded. Mortality follow-up was complete for 99% of hospital survivors for a mean period of 10 years. A second cohort of 623 consecutive patients with AMI hospitalized during January and February of 1992 in the same 13 coronary care units were followed up for 1 year after discharge.

RESULTS

Sex distribution and mean age were very similar in the two cohorts. Unadjusted in-hospital mortality was 18% in 1981-1983 versus 11% in 1992 (P < 0.001). After multiple regression analysis, the in-hospital mortality odds (adjusted for age, sex and history of previous infarction) declined from 1981-1983 to 1992 by 22-67%. The reduction in in-hospital mortality rates from 1981-1983 to 1992 was more pronounced among patients aged over 65 years. One-year survival was 91% and 92% in patients discharged in 1981-1983 and 1992, respectively; however, 1-year after discharge, the survival rate for patients older than 65 years was 85% in 1981-1983 versus 89% in 1992. None of the 5839 patients hospitalized in 1981-1983 received thrombolytic treatment or mechanical revascularization, whereas 46% and 9% of patients received these respective treatments in 1992.

CONCLUSIONS

This study suggests that, over the past decade, changes in medical treatment, thrombolytic therapy and mechanical revascularization have significantly contributed to the improvement of the immediate prognosis of patients hospitalized as a result of AMI.

Outcome of thrombolytic therapy in relation to hospital size and invasive cardiac services. The Investigators of the International Tissue Plasminogen Activator/Streptokinase Mortality Trial

OBJECTIVE

The outcome of patients with acute myocardial infarction who received thrombolytic therapy was assessed in relation to the size and comprehensiveness of cardiovascular services in the admitting hospitals.

METHODS

Two characteristics were obtained for each of the 438 hospitals: number of beds and in-house availability of cardiovascular services (coronary catheterization laboratory and coronary angioplasty or bypass surgery). Hospitals were grouped into four categories on the basis of size (< or = 300 vs > 300 beds) and availability of cardiovascular services. Baseline and outcome variables were compared by chi 2 analysis and logistic regression. Patients were followed up for 6 months.

RESULTS

Baseline variables were comparable among hospital categories except for significant differences in the distribution of antecedent angina and time to treatment. Significantly more coronary angioplasties and bypass surgeries were performed in patients first treated in hospitals with coronary revascularization services (4.1% and 4.2% vs 1.0% and 1.9%, P < .0001). Rates of strokes (1.9% vs 1.3% and 1.6%, P = .54), hospital mortality (11.9% vs 8.5%, (P = .11), and 6-month mortality (17.0% vs 11.8% and 12.3%, P = .03) were highest among patients treated in small hospitals that had coronary revascularization facilities. The rate of invasive procedures was higher in the smaller hospitals (odds ratio [OR], 1.44; 95% confidence limits [CL], 1.11 and 1.87; P = .006) and in hospitals with coronary revascularization services (OR, 4.05; 95% CL, 3.14 and 5.22; P < .0001); hemorrhage was more frequent in centers with coronary revascularization facilities (OR, 1.39; 95% CL, 1.13 and 1.71; P = .002). Rates of hospital mortality and 6-month mortality were similar.

CONCLUSIONS

Patients with acute myocardial infarction treated with thrombolytic therapy have the same mortality in small centers without in-house coronary revascularization services as in larger centers with such services.

After correcting for worse baseline characteristics, women treated with thrombolytic therapy for acute myocardial infarction have the same mortality and morbidity as men except for a higher incidence of hemorrhagic stroke. The Investigators of the International Tissue Plasminogen Activator/Streptokinase Mortality Study

BACKGROUND

In the prethrombolytic era, women with myocardial infarction were reported to have a worse outcome than men. This analysis evaluates the association of sex with morbidity and mortality after thrombolytic therapy.

METHODS AND RESULTS

Data were analyzed from 8261 of the 8387 randomized patients with acute myocardial infarction who received thrombolytic therapy in the International Tissue Plasminogen Activator/Streptokinase Mortality Study (baseline data were missing for 126 patients) and were followed for 6 months. Women made up 23% (n = 1944) of the study population. Baseline characteristics were worse in women: they were 6 years older, were more likely to have a history of previous infarction (P < .01), antecedent angina (P < .01), hypertension (P < .0001), or diabetes (P < .0001); were in a higher Killip class on admission (P < .0002); and received thrombolytic therapy 18 minutes later than men (P < .0001). Fewer women were smokers (P < .0001). Women had a higher hospital (12.1% versus 7.2%, P < .0001) and 6-month mortality (16.6% versus 10.4%, P < .0001) and were more likely to develop cardiogenic shock (9.1% versus 6.3%, P < .0001), bleeding (7.2% versus 5.3%, P < .01), and hemorrhagic (1% versus 0.3%, P < .001) or total stroke (2.2% versus 1.1%, P < .0001) during hospitalization. Reinfarction rates and requirement for angioplasty or surgery did not differ. After correction for worse baseline characteristics, women had similar morbidity and mortality apart from a significantly higher incidence of hemorrhagic stroke, which remained significant even after accounting for weight and treatment allocation (odds ratio, 2.90; P < .01).

CONCLUSIONS

After thrombolytic therapy for acute myocardial infarction, women have similar morbidity and mortality to men but suffer from a higher incidence of hemorrhagic stroke.

Significance of diabetes mellitus in patients with acute myocardial infarction receiving thrombolytic therapy. Investigators of the International Tissue Plasminogen Activator/Streptokinase Mortality Trial

OBJECTIVES

The purpose of this study was to evaluate the risks and benefits associated with thrombolytic therapy in patients with diabetes presenting with acute myocardial infarction.

BACKGROUND

Diabetes mellitus is associated with adverse risk factors and a hypercoagulable state that may adversely affect the outcome of thrombolytic therapy.

METHODS

Data were analyzed from 8,055 of the 8,239 patients with acute myocardial infarction who received thrombolytic therapy in the International Tissue Plasminogen Activator/Streptokinase Mortality trial (diabetes history was missing for 184 patients).

RESULTS

There were 883 patients with and 8,272 patients without diabetes. Among the diabetic patients, 160 were receiving insulin therapy. Baseline risk factors were significantly worse in diabetic patients, who were older and had a higher rate of previous infarction and antecedent angina and a higher Killip grade at admission. Bleeding and hemorrhagic and ischemic stroke rates were similar among diabetic and nondiabetic patients. Hospital and 6-month mortality rates were highest among diabetic patients receiving insulin therapy (16.9% and 23.1%, respectively), followed by diabetic patients not receiving insulin therapy (11.8% and 17.8%), and lowest in nondiabetic patients (7.5% and 10.7%, p < 0.0001). Whereas diabetes of 5 years' duration was associated with a mortality rate similar to that of nondiabetic patients, a > 5-year duration was associated with a relative mortality risk of 1.38 (95% confidence interval [CI] 0.88 to 2.15) and a > 10-year duration with a relative mortality risk of 1.99 (95% CI 1.40 to 2.81). The independent relative risk for incremental mortality from discharge to 6 months was 1.74 (95% CI 1.21 to 2.50). Mortality rate among diabetic patients was lowest in patients who received both streptokinase and heparin (9.8% vs. 16.1% in patients who received streptokinase but no heparin, p < 0.05).

CONCLUSIONS

The relative mortality of diabetic versus nondiabetic patients was similar to that observed in previous studies of patients with myocardial infarction not receiving thrombolytic therapy, indicating that mortality in diabetic patients receiving thrombolytic therapy is reduced to the same extent as in nondiabetic patients. In addition, risk of bleeding and stroke was not increased, indicating that diabetic patients can safely receive thrombolytic therapy for the same indications as nondiabetic patients.

Comparative case fatality analysis of the International Tissue Plasminogen Activator/Streptokinase Mortality Trial: variation by country beyond predictive profile. The Investigators of the International Tissue Plasminogen Activator/Streptokinase Mortality Trial

OBJECTIVES

This study was designed to examine the variation in mortality rates among countries participating in the International Tissue Plasminogen Activator/Streptokinase Mortality Trial.

BACKGROUND

Despite uniform inclusion and exclusion criteria and protocol in this trial, 30-day mortality rates (irrespective of treatment allocation) ranged from 4.2% to 14.8% among the participating countries.

METHODS

With use of the risk factors identified by a multi-variate logistic model, the total study group was classified into deciles on the basis of each patient's risk profile and individual probability of dying within 30 days. Expected mortality rates were then calculated and compared with actual mortality for each decile of the total study group, as well as for patients from each country.

RESULTS

Independent risk factors for mortality were older age (odds ratio 1.97 for each 10-year increment), systolic hypotension (blood pressure < 95 mm Hg) at entry (odds ratio 3.7), Killip class > 1 at entry (odds ratio 3.5), history of antecedent angina (odds ratio 1.23 to 1.49), history of diabetes mellitus (odds ratio 1.64), previous infarction (odds ratio 1.23) and history of never smoking (odds ratio 1.37). The overall mortality rate among the 1,612 patients in risk deciles 9 and 10 was 26%; for the 1,606 patients in deciles 1 and 2 it was 1.2%, with a sensitivity of 58.6% and a specificity of 83.7%. The logistic model closely predicted and explained the different mortality rates for most countries (the differences between expected and actual mortality were nonsignificant). However, in the total study group, the difference between the expected and actual mortality was significant (p < 0.001). This difference was mainly ascribed to the two countries with the highest and lowest mortality rates. When the patients from these two countries were excluded from the analysis, the overall difference became nonsignificant.

CONCLUSIONS

These findings suggest that the recognized risk factors associated with increased case fatality in acute myocardial infarction account only in part for mortality differences across or within populations.

Significance of smoking in patients receiving thrombolytic therapy for acute myocardial infarction. Experience gleaned from the International Tissue Plasminogen Activator/Streptokinase Mortality Trial

BACKGROUND

Despite the fact that smoking is a well-established risk factor for the development of coronary artery disease, some investigators have noted that hospital mortality after acute myocardial infarction is lower in patients who smoke than in nonsmoking patients. To evaluate the association of smoking with mortality during hospitalization after thrombolytic therapy and 6 months afterward, we analyzed the results of the International Tissue Plasminogen Activator/Streptokinase Mortality Trial.

METHODS AND RESULTS

Patients were divided into three groups: nonsmokers (those who never smoked), ex-smokers, and active smokers. Multivariate and univariate comparisons were made with respect to baseline characteristics and clinical outcome. There were 2,366 nonsmokers, 2,244 ex-smokers, and 3,649 active smokers. The baseline characteristics of nonsmoking patients differed significantly from the ex-smokers and active smokers. The nonsmoking group included more women than the ex-smokers or active smokers (45% versus 10.6% and 17.6%, respectively), was older (67 +/- 10 years versus 64 +/- 10 years and 58 +/- 11 years), had a higher rate of diabetes mellitus (16.3% versus 11.1% and 7.5%), and had a worse Killip class at admission. Nonsmoking patients and ex-smokers experienced more in-hospital reinfarction than active smokers (4.7% and 5% versus 2.7%, p < 0.0001, respectively). Nonsmokers experienced more in-hospital shock than the ex-smokers or active smokers (9.2% versus 6.4% and 5.8%, p < 0.0001), stroke (1.9% versus 1.8% and 0.8%, p < 0.0001), and bleeding (7.2% versus 6.5% and 4.4%, p < 0.0001). They also experienced a higher in-hospital and 6-month mortality (12.8% and 17.6%) than ex-smokers (8.2% and 12.1%) or active smokers (5.4% and 7.8%) (p < 0.0001). A multivariate analysis accounting for all baseline characteristics demonstrated a significant association between nonsmoking and increased hospital mortality, with an odds ratio of 1.42 (confidence limits, 1.15-1.72). Among active smokers, there was a nonsignificant trend for mortality rates to decrease with increasing numbers of cigarettes smoked per day.

CONCLUSIONS

This retrospective analysis indicates that smokers receiving thrombolytic therapy after acute myocardial infarction have significantly better hospital and 6-month outcome than nonsmokers or ex-smokers. However, smokers sustained their infarction at a significantly earlier age than nonsmokers, and strenuous efforts should continue to be made to decrease the incidence of new and continued smoking.

Rapid resolution of new right bundle branch block in acute anterior myocardial infarction patients after thrombolytic therapy

The objectives of this retrospective study are to describe the effect of thrombolytic treatment on the clinical course of patients with acute anterior myocardial infarction complicated by acute right bundle branch block. Patients admitted to the intensive cardiac care unit within < 4 hours from onset of symptoms, and demonstrating an acute right bundle branch block with, or without left axis deviation, on the qualifying ECG were included. All were given intravenous thrombolytic treatment consisting of: streptokinase (1,500,000 IU/40 min) or recombinant tissue type plasminogen activator (120 mg/6 hours). Following admission, patients were continuously monitored and a 12-lead ECG was recorded during each of the first 3 hours and then every 3 hours over the next 21 hours. Eight patients were included (8/211 = 3.8%). Their mean age was 62 +/- 7 years and time elapse from onset to treatment was 122 +/- 26 minutes. Complete resolution of the right bundle branch block occurred within < 3 hours in all and left axis deviation normalized in two patients. Mean peak creatine kinase was 1214 +/- 604 IU and global left ventricular ejection fraction, measured by isotope ventriculography within 24 hours from admission, was 39% +/- 15%. Only one patient was prophylactically paced. In the others, rapid normalization of the conduction block with reperfusion exceeded the logistics required for the transvenous pacemaker implantation procedure. Coronary angiography performed in six patients during 72 hours from admission revealed high grade stenoses in the proximal portion of the left anterior descending coronary artery in five patients and complete occlusion in one.(ABSTRACT TRUNCATED AT 250 WORDS)

Antecedent angina pectoris predicts worse outcome after myocardial infarction in patients receiving thrombolytic therapy: experience gleaned from the International Tissue Plasminogen Activator/Streptokinase Mortality Trial

The significance of antecedent angina in predicting clinical outcome was assessed in 8,329 patients with acute myocardial infarction who received thrombolytic therapy with either recombinant tissue-type plasminogen activator or streptokinase. There were 2,370 patients with antecedent angina for greater than 1 month, 1,512 patients with antecedent angina for less than or equal to 1 month and 4,447 patients with no antecedent angina. The longer the duration of angina, the worse the baseline characteristics in the three groups: the mean patient age was 65 versus 62 versus 61 years, respectively (p less than 0.0001); the rate of previous myocardial infarction was 37% versus 18% versus 10% (p less than 0.0001); and the rate of hypertension was 40% versus 31% versus 27% (p less than 0.0001). Antecedent angina was associated with a longer hospital stay (11.3 and 11.7 days vs. 10.8 days, p less than 0.0001), a higher incidence of bypass surgery (2.2% vs. 1.2% vs. 0.7%, p = 0.0001), a worse Killip class at discharge (10.6% of patients in class greater than 1 vs. 8.7% vs. 6.4%, p = 0.0001), and a higher hospital and 6-month mortality (12.1% and 18% vs. 8.9% and 11.6% vs. 6.6% and 9.2%, respectively, p less than 0.0001). A multivariate analysis taking into account all baseline characteristics confirmed the independent association of antecedent angina with mortality, with a relative risk of 1.4 to 1.47 (p less than 0.001). Antecedent angina predicts a worse clinical outcome and a more intense use of medical resources in patients with acute myocardial infarction receiving thrombolytic therapy.

Incidence of left ventricular thrombi formation after thrombolytic therapy with recombinant tissue plasminogen activator, heparin, and aspirin in patients with acute myocardial infarction

To evaluate the prevalence of left ventricular thrombi after thrombolytic therapy, 144 consecutive patients with acute myocardial infarction (AMI) were prospectively studied with two-dimensional echocardiography 1 and 8 days after admission. Patients were treated 2.1 +/- 0.8 hours after the onset of symptoms. Thrombolytic protocol included 120 mg of recombinant tissue plasminogen activator (rt-PA), 5000 IU of heparin, followed by a continuous infusion of 25,000 IU/24 hours for at least 5 days, and 250 mg of aspirin a day. Seventy-six patients had AMI of the anterior wall; of these, seven (9.2%) developed left ventricular thrombi. The remaining 68 patients had infarctions of the inferior wall; of these, two (2.9%) developed left ventricular thrombi. Since anterior wall infarction not treated with thrombolytic therapy is associated with a 25% to 40% rate of left ventricular thrombi, we conclude that early thrombolytic therapy with rt-PA, heparin, and aspirin reduces the formation of left ventricular thrombus in AMI of the anterior wall. Apical left ventricular thrombi developed more frequently in patients with previous infarctions compared with those without (4 of 17 versus 4 of 127, p = 0.01). During the 12-month follow-up period, no patient in the study had manifestations of peripheral emboli.

Prognostic importance of delayed Q-wave evolution 3 to 24 hours after initiation of thrombolytic therapy for acute myocardial infarction

The timing of Q-wave evolution and its prognostic significance was studied in 201 patients who received thrombolytic therapy for a first acute myocardial infarction (AMI). One hundred forty-one patients (70%) had evidence of a Q-wave AMI within 3 hours of the initiation of thrombolytic therapy, 31 (16%) developed Q waves after 3 hours but before hospital discharge, and 29 (14%) were discharged with a non-Q-wave AMI. Laboratory indicators of myocardial damage and in-hospital morbidity and mortality were greater among patients with Q-wave AMIs than with non-Q-wave AMIs. When these indexes were examined with respect to the timing of Q-wave evolution, the prognosis of patients with delayed Q-wave development was similar to that of patients with non-Q-wave AMIs. Thus, compared to patients with early (less than or equal to 3 hours) Q-wave evolution, patients with delayed Q-wave evolution or with a non-Q-wave AMI had a smaller creatine kinase peak (mean 661 to 1,081 vs 1,251 to 1,541 IU; p = 0.005), better preservation of left ventricular function as measured by radionuclide ventriculography before discharge (mean +/- standard deviation 54 +/- 11% vs 47 +/- 13%; p less than 0.01), and a lower incidence of congestive heart failure at discharge (3 vs 15%; p = 0.02). In-hospital mortality was lower among patients with delayed Q-wave evolution or with a non-Q-wave AMI (5 of 141 vs 0 of 60; difference not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Repeat infusion of recombinant tissue-type plasminogen activator in patients with acute myocardial infarction and early recurrent myocardial ischemia

When conventional treatment of patients with early clinical reinfarction after thrombolytic therapy fails, mechanical revascularization may be attempted. An alternative strategy, repeat thrombolytic infusions, is reported. Fifty-two patients with acute myocardial infarction were treated with one or two additional thrombolytic infusions of recombinant tissue-type plasminogen activator (rt-PA) because of nonsustained ischemia after initial treatment with rt-PA or streptokinase. Thirty-five patients received the second infusion within 1 h of the first; 13 patients received the second infusion 1 to 72 h after the first and 4 patients received it later during their hospitalization. Bleeding complications occurred in 10 patients (19%); however, most of these were minor (no intracranial bleeding) and only 2 patients required blood transfusion. In 14 patients in whom the decrease in fibrinogen and plasminogen levels was measured after the first and second infusions, this decrease was only 25% and 63%, respectively--only slightly higher than the 22% and 53% decreases measured in 63 patients who had only one rt-PA infusion. In 44 patients (85%), the acute ischemia resolved completely within 1 h after initiation of the second infusion. In 23 patients (44%), pain and ST segment elevation did not recur and invasive coronary intervention was avoided. Thus, repeat rt-PA infusions can stabilize a substantial number of patients with acute reinfarction and, even when relief is temporary, repeat rt-PA infusions can minimize myocardial damage while patients await mechanical revascularization.

Rapid resolution of ST elevation and prediction of clinical outcome in patients undergoing thrombolysis with alteplase (recombinant tissue-type plasminogen activator): results of the Israeli Study of Early Intervention in Myocardial Infarction

Alteplase (recombinant tissue-type plasminogen activator (rt-PA)) was infused within four hours of onset of symptoms in 286 patients with acute myocardial infarction. Delayed coronary angiography was performed 72 hours after admission with coronary angioplasty if indicated. Electrocardiographic monitoring was continuous during the first hour of treatment. The sum of the ST segment elevations (sigma ST) was calculated on electrocardiograms recorded at entry and an hour later. ST elevations resolved rapidly within one hour of treatment in 189 patients and persisted in 97 patients. Rapid resolution of ST elevation correlated with angiographic coronary patency as determined by coronary angiography 72 hours after admission. The patients with rapid resolution of sigma ST had significantly smaller infarcts and a better clinical outcome than the patients with persistent ST elevation. sigma ST values at entry and one hour after treatment had no additional independent predictive value. Rapid resolution of ST elevations in patients undergoing thrombolysis with alteplase was associated with a significantly smaller release of creatine kinase, better preservation of left ventricular function, lower morbidity, and less short and long term mortality. Rapid resolution of sigma ST elevation is an efficient indicator of clinical outcome in groups of patients with acute myocardial infarction undergoing thrombolysis with alteplase.

Randomized controlled trial of late in-hospital angiography and angioplasty versus conservative management after treatment with recombinant tissue-type plasminogen activator in acute myocardial infarction

Although both the European Cooperative Study Group and the Thrombolysis in Myocardial Infarction IIB trial indicated that angiography and angioplasty as routine measures after thrombolytic treatment do not improve clinical outcome in patients with acute myocardial infarction, the potential benefit of angioplasty may have been negated by the fact that the procedure was performed too soon (less than 32 hours) after admission. A similar study was designed in which delayed invasive treatment was compared with conservative treatment in 201 patients with acute myocardial infarction given recombinant tissue-type plasminogen activator. The 97 patients randomized to the invasive group underwent routine coronary angiography and angioplasty 5 +/- 2 days after thrombolytic therapy, whereas the 104 patients randomized to the conservative group underwent angiography only for recurrent postinfarction angina or exercise-induced ischemia. Baseline characteristics of both groups were similar. In the invasive group, 92 patients underwent angiography, 49 angioplasty and 11 coronary artery bypass surgery. In the conservative group, 40 patients experienced early ischemia, 39 underwent angiography, 20 angioplasty and 4 coronary artery bypass surgery. Reinfarction rate and preservation of left ventricular function at discharge or 8 weeks after discharge did not differ in the 2 groups. Total mortality after a mean follow-up of 10 months was 8 of 97 in the invasive and 4 of 104 in the conservative groups (p = 0.15). However, if only patients who died after the timing of the scheduled protocol catheterization in the invasive arm were included, mortality was 5 of 94 and 0 of 100 in the invasive and conservative treatment groups, respectively (p = 0.02). (ABSTRACT TRUNCATED AT 250 WORDS)

Improved survival but not left ventricular function with early and prehospital treatment with tissue plasminogen activator in acute myocardial infarction

One hundred ninety patients with acute myocardial infarction (AMI) were treated with recombinant tissue-type plasminogen activator (rt-PA) 2.0 +/- 0.8 hours after the onset of symptoms. Eighty-seven patients were enrolled via mobile intensive care units and 103 through the emergency ward. Patients who were enrolled via the mobile intensive care units were randomized to immediate, prehospital treatment initiation, or to delayed, in-hospital treatment initiation. All 190 patients except 2 underwent delayed coronary angiography and, when indicated, angioplasty at 72 hours after enrollment. Patients treated within 2 hours and those treated 2 to 4 hours after symptom onset had similar preservation of left ventricular function, and similar prevalence of congestive heart failure at discharge. Patients treated within 2 hours of symptom onset had significantly lower short- (0.0 vs 6.3%, p = 0.01) and long-term (1.0 vs 9.5%, p = 0.03) mortality. Prehospital initiation of rt-PA appeared to be safe and feasible and resulted in a 40-minute decrease in the time from symptom onset to treatment initiation.

Importance of reciprocal ST segment depression in leads V5 and V6 as an indicator of disease of the left anterior descending coronary artery in acute inferior wall myocardial infarction

The purpose of this study was to determine the coronary angiographic correlations (specifically disease of the left anterior descending coronary artery) of reciprocal ST segment depression appearing during inferior acute myocardial infarction. Forty six patients (41 men and five women; mean age 56 years) were allocated into two groups based on the extent of precordial ST segment depression: widespread (V1-V6) ST depression v localised (V1-V4) ST depression. Patients with no reciprocal ST depression or patients with ST depression in V1-V4 but with ST elevation in V5 and V6 (inferolateral acute myocardial infarction) were excluded. All patients were catheterised during hospital admission for infarction. Twenty four of the 28 patients with ST depression in V1-V6 had significant lesions in the left anterior descending coronary artery whereas 16 of the 18 patients with ST depression in V1-V4 had insignificant or no lesions in the left anterior descending artery. The sensitivity, specificity, and positive and negative predictive values of widespread ST depression in predicting disease in the left anterior descending coronary artery were 92%, 80%, and 86% and 89% respectively. In patients with inferior acute myocardial infarction and precordial ST depression, the extent of ST depression is of clinical significance. Widespread (V1-V6) ST depression suggests disease of the left anterior descending coronary artery, whereas localised ST depression (V1-V4) indicates its absence.

Should thrombolytic therapy be administered in the mobile intensive care unit in patients with evolving myocardial infarction? A pilot study

The growing recognition of the importance of early thrombolysis in evolving myocardial infarction was the basis for the present study, which evaluated the effectiveness, feasibility and safety of prehospital thrombolytic therapy. In a relatively small study, 118 patients were allocated to receive either prehospital treatment with recombinant tissue-type plasminogen activator (rt-PA) in the mobile intensive care unit (group A, 74 patients) or hospital treatment (group B, 44 patients). A total of 120 mg of rt-PA was infused over a period of 6 h. All patients were fully heparinized and underwent radionuclide left ventriculography and coronary angiography during hospitalization. Although group A was treated significantly earlier than group B after onset of symptoms (94 +/- 36 versus 137 +/- 45 min, respectively; p less than 0.001), no significant differences were observed between the groups in 1) extent of myocardial necrosis, 2) global left ventricular ejection fraction at discharge, 3) patency of infarct-related artery, 4) length of hospital stay, and 5) mortality at 60 days. However, a trend to a lower incidence of congestive heart failure at hospital discharge was observed in the prehospital-treated compared with the hospital-treated group (7% versus 16%, respectively; p = NS). No major complications occurred during transportation. It is concluded that myocardial infarction can be accurately diagnosed and thrombolytic therapy initiated relatively safely during the prehospital phase by the mobile intensive care team, thus instituting a beneficial clinical trend in favor of prehospital thrombolysis.

Early thrombolytic therapy does not enhance the recovery of the right ventricle in patients with acute inferior myocardial infarction and predominant right ventricular involvement

In this study we report the effects of early thrombolytic therapy on the recovery of the right ventricle after an acute myocardial infarction. Sixty-five patients presenting with their first inferior myocardial infarction and predominant right ventricular involvement were consecutively treated as follows: group A (20 patients) conservatively (without thrombolytic therapy), group B (19 patients) with streptokinase and group C (26 patients) with recombinant tissue type plasminogen activator. Coronary angiography was performed within 72 h after admission in 52 patients (10 of group A, 18 of group B and in 24 patients of group C) followed by transluminal coronary angioplasty in 26. All groups had similar characteristics except for a higher mean age in group A. Within 3 months, a remarkable improvement in right ventricular function and a major increase in ejection fraction was observed for all three patient groups. Improvement of right ventricular function was more prominent in patients with residual flow through the infarct-related artery. The beneficial course was comparable in all the groups, unaffected by the type of medical treatment applied, or by the performance of coronary angioplasty. No further significant change occurred beyond this period. Thus, early thrombolytic therapy does not augment the generally favorable course of recovery of the right ventricle from acute infarction.

Comparison of three inducement techniques to improve compliance in a health survey conducted by telephone

The use of telephone interviews for epidemiologic and public health studies has increased in recent years. Since telephone surveys are susceptible to lower response rates than personal interviews, several attempts have been reported to increase respondents' compliance using various precontact procedures. This investigation evaluates the comparative effectiveness of three techniques to enhance compliance with a relatively long telephone interview on epidemiologic topics. The theoretical and practical applications in the domain of telephone surveys of two techniques, the foot-in-the-door and the low ball, commonly considered nonpressure techniques, are discussed. A newly suggested, combined compliance procedure is also introduced and tested. Results show that compliance was greater for the new method when compared with each of the other two methods. Moreover, each of the three methods outperformed a control condition. The theoretical models developed to devise and explain the new techniques received empirical support in a public health survey employing 335 adult residents of Tel Aviv, Israel, in May 1988.

Continuous rt-PA infusion as a salvage strategy to maintain patency of the infarct artery; safety of high cumulative dose and subsequent emergency coronary artery angioplasty and bypass surgery

Acute re-occlusion of an infarct artery reperfusion attained by thrombolytic therapy may be treated by emergency coronary angioplasty or bypass surgery. Repeated infusion of a thrombolytic agent is an additional treatment strategy. Three patients with reinfarctions that occurred very early after successful reperfusion were treated with continuous infusion of recombinant tissue-type plasminogen activator (rt-PA). These patients received a rt-PA dose of 300-360 mg while they awaited emergency mechanical revascularization procedures. Two patients had coronary angioplasty immediately after receiving repeated infusions of rt-PA and one underwent coronary bypass surgery while receiving a third rt-PA infusion. There were no bleeding complications in the 2 patients who underwent coronary angioplasty, and no excessive bleeding in the patient who received coronary bypass surgery. Thus, repeated continuous rt-PA infusions can be used to maintain the patency of recurrently occluding infarct arteries until definitive mechanical revascularization can be performed.

Correlation of baseline plasminogen activator inhibitor activity with patency of the infarct artery after thrombolytic therapy in acute myocardial infarction

Increased levels of plasminogen activator inhibitor (PAI) have recently been described in patients with acute myocardial infarction (AMI). To correlate PAI levels to patency of infarct arteries after thrombolytic therapy with recombinant tissue-type plasminogen activator (rt-PA), 125 consecutive patients with AMI were examined. Blood levels of fibrinogen, plasminogen, tissue plasminogen activator (t-PA) and PAI were measured before treatment initiation, 10 minutes after completion of rt-PA infusion and 24 and 48 hours after treatment. Coronary angiography, performed in all patients 72 hours after beginning rt-PA infusion, revealed patent infarct arteries in 97 patients and occluded infarct arteries in 28 patients. Pretreatment levels of PAI were significantly higher in patients with occluded infarct arteries (18.0 +/- 11.5 vs 10.5 +/- 9.3 IU/ml, p less than 0.01). Conceivably, higher levels of PAI may interfere with the natural thrombolytic process and make pharmacologic thrombolytic intervention less effective.

Management control of aeromedical evacuation systems

Aeromedical evacuation has been extensively used by military forces for evacuation of wartime casualties, but has also proven useful in civilian disaster response. In contrast to the broad coverage of the clinical aspects of the aeromedical evacuation, the operational and management control issues have rarely been addressed. The sophisticated battlefield of the 1980s has had an impact also in air evacuation, adding to the factors to be considered before launching an evacuation mission. The professional control of aeromedical evacuation is, therefore, crucial to the efficient and smooth operation of this high-cost resource. In an attempt to shed light on some of the operational perspectives of military air evacuation, the Israeli experience in the management control of such systems is discussed.

Need for better severity indexes of acute myocardial infarction under diagnosis-related groups

Clinical, demographic and administrative data, including length of stay and institutional charges, were examined for 219 patients hospitalized for acute myocardial infarction (AMI). Neither length of stay nor charges differed among AMI patients with or without cardiovascular complications as defined by Medicare's diagnosis-related group (DRG) categories (DRG 121 and 122, respectively) for patients who are discharged alive. Myocardial enzyme peak levels are the best predictors of hospital resource consumption for patients with AMI when considered alone or in combination with other factors. The "cardiovascular complications" designated by discharge diagnoses did not reflect resource consumption in our patient population. Sixteen percent of the patients studied underwent cardiac catheterization during hospitalization. These patients stayed in the hospital longer and incurred 70% higher charges; nevertheless, they were grouped with the remaining AMI patients in the current DRG formulation. Clinical evaluations such as cardiovascular complications are subject to interpretation, and are therefore less credible than enzyme measurements for recognizing the severity of a patient's AMI. Reimbursement based on objective measurements may avoid payment inequities.

Coronary angioplasty under the prospective payment system: the need for a severity-adjusted payment scheme

To evaluate the adequacy of Diagnosis Related Group prospective payment for percutaneous transluminal coronary angioplasty, the clinical characteristics, length of stay and hospital charges of all patients undergoing this procedure at Boston's Beth Israel Hospital during a 100 day period were examined. Of 113 such patients, the 61 patients in whom nonelective dilation was performed for unstable or postinfarction angina had a significantly greater length of stay and total hospital charge (10 +/- 6 days and $14,700 +/- $7,400, respectively) than did the 52 patients in whom elective dilation was performed (6 +/- 5 days and $8,500 +/- $7,700, respectively, p less than 0.0001). Under the current prospective payment system, however, these two groups of patients would have been placed in the same Diagnosis Related Group, and would have thus commanded equal institutional reimbursement. One potential revision of the payment system is presented to help to deal with this disparity.