Gender and acute myocardial infarction: is there a different response to thrombolysis?

OBJECTIVES

This study sought to 1) determine the effect of gender on early and late infarct-related artery patency and reocclusion after thrombolytic therapy for acute myocardial infarction; 2) examine the effect of gender on left ventricular function in response to injury/reperfusion; and 3) assess the independent contribution of gender to early (30-day) mortality after acute myocardial infarction.

BACKGROUND

Women have a higher mortality rate than men after myocardial infarction. However, the effect of gender on infarct-related coronary artery patency and left ventricular response to injury/reperfusion have not been fully defined in the thrombolytic era.

METHODS

Patency rates and global and regional left ventricular function were determined in patients at 90 min and 5 to 7 days after thrombolytic therapy for acute myocardial infarction. The effect of gender on infarct-related artery patency and left ventricular function was determined. Thirty-day mortality differences between women and men were compared.

RESULTS

Women were significantly older and had more hypertension, diabetes, hypercholesterolemia, heart failure and shock. They were less likely to have had a previous myocardial infarction, history of smoking or previous bypass surgery. Ninety-minute patency rates (Thrombolysis in Myocardial Infarction [TIMI] flow grade 3) in women and men were 39% and 38%, respectively (p = 0.5). Reocclusion rates were 8.7% in women versus 5.1% in men (p = 0.14). Women had more recurrent ischemia than men (21.4% vs. 17.0%, respectively, p = 0.01). Ninety-minute ejection fraction and regional ventricular function were clinically similar in women and men with TIMI 2 or 3 flow (ejection fraction [mean +/- SD]: 63.4 +/- 6% vs. 59.4 +/- 0.7%, p = 0.02; number of chords: 21.4 +/- 0.9 vs. 21.0 +/- 1.9, p = 0.7; SD/chord: -2.4 +/- 08 vs. -2.4 +/- 0.2, p = 0.9, respectively). No clinically significant differences in left ventricular function were noted at 5- to 7-day follow-up. Women had a greater hyperkinetic response than men in the noninfarct zone (SD/chord: 2.4 +/- 0.2 vs. 1.7 +/- 0.1, p = 0.005). The 30-day mortality rate was 13.1% in women versus 4.8% in men (p < or = 0.0001). After adjustment for other clinical and angiographic variables, gender remained an independent determinant of 30-day mortality.

CONCLUSIONS

Women do not differ significantly from men with regard to either early infarct-related artery patency rates or reocclusion after thrombolytic therapy or ventricular functional response to injury/reperfusion. Gender was an independent determinant of 30-day mortality after acute myocardial infarction.

Angiographic findings and outcome in diabetic patients treated with thrombolytic therapy for acute myocardial infarction: the GUSTO-I experience

OBJECTIVES

This study sought to determine whether diabetes mellitus, in the setting of thrombolysis for acute myocardial infarction, affects 1) early infarct-related artery patency and reocclusion rates; and 2) global and regional ventricular function indexes. We also sought to assess whether angiographic or baseline clinical variables, or both, can account for the known excess mortality after myocardial infarction in the diabetic population.

BACKGROUND

Mortality after acute myocardial infarction in patients with diabetes is approximately twice that of nondiabetic patients. It is uncertain whether this difference in mortality is due to a lower rate of successful thrombolysis, increased reocclusion after successful thrombolysis, greater ventricular injury or a more adverse angiographic or clinical profile in diabetic patients.

METHODS

Patency rates and global and regional left ventricular function were determined in patients enrolled in the GUSTO-I Angiographic Trial. Thirty-day mortality differences between those with and without diabetes were compared.

RESULTS

The diabetic cohort had a significantly higher proportion of female and elderly patients, and they were more often hypertensive, came to the hospital later and had more congestive heart failure and a higher number of previous myocardial infarctions and bypass surgery procedures. Ninety-minute patency (Thrombolysis in Myocardial Infarction [TIMI] flow grade 3) rates in patients with and without diabetes were 40.3% and 37.6%, respectively (p = 0.7). Reocclusion rates were 9.2% vs. 5.3% (p = 0.17). Ejection fraction at 90 min after thrombolysis was similar in diabetic and nondiabetic patients ([mean +/- SEM] 6.10 +/- 1.6% vs. 60.1 +/- 0.7%, p = 0.7), as was regional ventricular function (number of abnormal chords: 19.1 +/- 2.0 vs. 17.5 +/- 0.8, p = 0.3; SD/chord: -2.3 +/- 0.2 vs. -2.4 +/- 0.1, p = 0.6). Diabetic patients had less compensatory hyperkinesia in the noninfarct zone (SD/ chord: 1.3 +/- 0.2 vs. 1.7 +/- 0.1, p < or = 0.01). No significant difference in ventricular function was noted at 5- to 7-day follow-up. The 30-day mortality rate was 11.3% in diabetic versus 5.9% in nondiabetic patients (p < or = 0.0001). After adjustment for clinical and angiographic variables, diabetes remained an independent determinant of 30-day mortality (p = 0.02).

CONCLUSIONS

Early (90-min) infarct-related artery patency as well as regional and global ventricular function do not differ between patients with and without diabetes after thrombolytic therapy, except for reduced compensatory hyperkinesia in the noninfarct zone among patients with diabetes. Diabetes remained an independent determinant of 30-day mortality after correction for clinical and angiographic variables.

Evolution of early TIMI 2 flow after thrombolysis for acute myocardial infarction. GUSTO-1 Angiographic Investigators

BACKGROUND

Patients with early Thrombolysis in Myocardial Infarction (TIMI) grade 2 flow after thrombolysis appear to have outcomes similar to thrombolytic failures. To evaluate the origin and evolution of early TIMI 2 flow, we examined early and late angiographic and ventriculographic data from the Global Utilization of Streptokinase and TPA for Occluded Arteries (GUSTO-1) angiographic study.

METHODS AND RESULTS

Of the 914 patients with both 90-minute and 5- to 7-day catheterizations, 278 patients had TIMI grade 2 flow at 90 minutes. At follow-up, 188 (67%) had improved to TIMI grade 3 flow. At 90 minutes, patients with TIMI grade 2 flow had greater infarct vessel narrowing and a significantly greater incidence of thrombus than patients with TIMI grade 3 flow. At the 5- to 7-day follow-up, patients whose flow had improved from TIMI grade 2 at 90 minutes to grade 3 flow at follow-up had larger-caliber vessels (minimum luminal diameter, 0.99 +/- 0.47 versus 0.84 +/- 0.48 mm; P = .03) and a lower incidence of visible thrombus (26% versus 38%, P = .04) than those with persistent TIMI grade 2 flow. These patients also had a higher mean ejection fraction (57.5 +/- 14.1% versus 52.8 +/- 12.9%, P = .02) and better infarct zone wall motion (-2.1 +/- 1.5 versus -2.6 +/- 1.3 SD per chord, P = .01) at the 5- to 7-day follow-up. Patients in whom flow improved from TIMI grade 2 at 90 minutes to TIMI grade 3 by 5 to 7 days had significantly better left ventricular function than patients with persistent TIMI grade 0, 1, or 2 flow and constituted a group whose left ventricular function was intermediate between those who had no reperfusion (TIMI grades 0 and 1) and those whose reperfusion was complete (TIMI grade 3).

CONCLUSIONS

These data suggest that incomplete clot lysis plays a significant role in the pathogenesis of TIMI grade 2 flow. Furthermore, early TIMI grade 2 flow may be sufficient to provide prolonged myocyte viability, which will further recover if flow normalizes.

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.

The role of oak pollen in hay fever consultations in general practice and the factors influencing patients' decisions to consult

BACKGROUND

Patients often consult for hay fever before significant counts of grass pollen are recorded, and this has prompted the question, 'Are symptoms already present or are patients consulting to obtain medication in anticipation?'

AIM

The study is concerned with the relationship between hay fever symptoms and pollens, and also with the impact of the media on patient consulting behaviour.

METHOD

Symptom questionnaires were presented to patients consulting with hay fever for the first time that year in 1994 in four Birmingham practices. The questionnaire concerned the nature and duration of symptoms and the influence of the media on their decision to consult. Incidence data collected over the spring and summer periods (1989-1995) in the Weekly Returns Service (WRS) were examined in relation to pollen counts reported by the Midlands Asthma and Allergy Research Association at Derby. Data are presented for oak, birch and grass pollen, but other pollen data including rape, nettle and other trees were also examined.

RESULTS

Questionnaire data from 1994 were analysed in two periods starting from 4 April: early (day 1-60) and late (day 61-124). Out of the 364 subjects, 38% consulted in the early period and 62% in the late period. Altogether, 41% developed symptoms before the start of the grass pollen season. Overall, 91% of patients first consulting in the early period had already experienced symptoms compared with 99% late period and were not simply collecting prescriptions in anticipation. The influence of the media on consultation behaviour was very small, except in children, 23% of whom (or their parents) were reported to be influenced. The new episode data from the WRS examined over 7 years showed an early peak that was coterminous with oak pollen, and a later and higher peak with grass pollen.

CONCLUSION

The consistency of the relationship between oak pollen and the early peak of hay fever over the years examined suggests that oak pollen is a major cause of hay fever symptoms.

Increased left ventricular dysfunction in elderly patients despite successful thrombolysis: the GUSTO-I angiographic experience

OBJECTIVE

This study sought to determine whether the recovery of regional and global left ventricular function is reduced in elderly patients despite successful thrombolytic therapy for acute myocardial infarction. Comparisons were made between elderly (> or = 75 years old, n = 47) and adult (< 75 years old, n = 434) patients enrolled in the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO) angiographic trial who underwent catheterization at 90 min and 5 to 7 days after thrombolysis and who had an open infarct-related artery with Thrombolysis in Myocardial Infarction (TIMI) grade 2 to 3 flow at both times.

BACKGROUND

The morbidity and mortality of acute myocardial infarction is increased in elderly patients, presumably because of multiple adverse coexistent baseline variables. However, functional recovery after thrombolysis has not been characterized in the elderly.

METHODS

Ejection fraction, end-systolic volume index, infarct and noninfarct zone contractile function (SD/chord) and infarct extent (number of chords) were determined.

RESULTS

At 90 min, elderly patients with an open infarct-related artery had decreased infarct zone contractile function (-2.8 +/- 0.2 vs. -2.3 +/- 0.1 SD/chord in adults, p < or = 0.05) and a greater extent of injury (26.0 +/- 2.6 vs. 20.7 +/- 0.8 chords in adults, p < or = 0.05). At 5- to 7-day follow-up ventriculography, ejection fraction was reduced, and end-systolic volume index was significantly increased in elderly patients compared with adults. The severity of regional wall motion dysfunction in the infarct zone was also greater in the elderly than in adults at 5- to 7-day follow-up (-2.6 +/- 0.2 vs. -1.9 +/- 0.1 SD/chord, respectively, p < or = 0.005). Non-infarct zone contractile function at 90-min ventriculography was similar in both groups. Despite a patent infarct-related artery at 90-min, the 30-day mortality rate in the elderly remained elevated (17.8%) compared with that of adults (4%) (p < or = 0.0001). Elderly patients were predominantly female and had a higher prevalence of hypertension, multivessel coronary disease, previous infarction, anterior infarctions and later time to treatment (between 3 and 6 h) than adults. However, age > or = 75 years remained an independent determinant by multivariable regression analysis of 1-week postinfarction end-systolic volume index, regional left ventricular dysfunction (p = 0.02 and p < or = 0.008, respectively) and 30-day mortality (p < or = 0.0001).

CONCLUSIONS

Elderly patients had increased damage in the infarct zone and had persistently increased mortality despite sustained infarct-related artery patency after successful thrombolysis. Although the causes are probably multifactorial, a more rapid progression of ischemic injury or a blunted postreperfusion recovery appears to contribute to the poorer outcomes in elderly patients.

Non-invasive prediction of reperfusion and coronary artery patency by continuous ST segment monitoring in the GUSTO-I trial

In the GUSTO-I ECG ischaemia monitoring substudy, 1067 patients underwent continuous ST segment monitoring, using vector-derived 12-lead (406 patients), 12-lead (373 patients) and 3-lead Holter (288 patients) ECG recording systems. Simultaneous angiograms at 90 or 180 min following thrombolytic therapy were performed as a part of the prospective study in 302 patients. Infarct vessel patency was established as TIMI perfusion grades 2 or 3 and occlusion as TIMI perfusion grades 0 or 1. Coronary artery patency was predicted from ST trends up to the time of angiography. Predictive values at 90 and 180 min after the start of thrombolysis were 70% and 82% for patency and 58% and 64% for occlusion, respectively. In retrospect, accuracy appeared greatest (79-100%) in patients with extensive ST segment elevation (> or = 400 microV), if both speed of ST recovery and extent of ST segment elevation were taken into account. Although the three recording systems differed considerably in signal processing, no significant difference in accuracy was demonstrated among these systems. We conclude that continuous ECG monitoring may help select high risk patients without apparent reperfusion who may benefit from additional reperfusion therapy. As ST recovery may occur early after the start of thrombolytics and accuracy of the test is related to peak ST levels, the use of on-line ECG monitoring devices on emergency wards and cardiac care units is recommended.

Heart rate variability assessment early after acute myocardial infarction. Pathophysiological and prognostic correlates. GUSTO ECG Substudy Investigators. Global Utilization of Streptokinase and TPA for Occluded Arteries

BACKGROUND

Diminished heart rate variability is associated with less favorable prognosis after myocardial infarction. However, the prognostic value of early (first 48 hours) measurement and the influence of thrombolytic strategies, myocardial infarction location, left ventricular function, ST-segment shift, and infarct-related artery patency on heart rate variability have not been examined comprehensively.

METHODS AND RESULTS

Heart rate variability and ST-segment analysis of 48-hour Holter tapes were performed with the use of a commercial system in 204 patients who were part of an ST-monitoring substudy of the Global Utilization of Streptokinase and TPA for Occluded Arteries (GUSTO-I) trial. Both time-domain measures (SD of the average normal RR interval for all 5-minute segments of a 24-hour ECG recording [SDANN] and percent difference between adjacent normal RR intervals > 50 ms computed over the entire 24-hour ECG recording [pNN50]) and frequency-domain measures (low frequency [LF], high frequency [HF], and LF/HF ratio) were assessed on days 1 and 2 after acute myocardial infarction. Coronary angiography performed within the first 24 hours was also available in 75% of the patients. All heart rate variability measures decreased between day 1 and day 2 (P = .001) except the LF/HF ratio. There was no difference in heart rate variability among groups assigned to one of four different thrombolytic treatment strategies (streptokinase/subcutaneous heparin, streptokinase/intravenous heparin, accelerated tissue plasminogen activator, and combination streptokinase/tissue plasminogen activator). Heart rate variability measures were lower in anterior versus nonanterior infarcts (SDANN, 53 +/- 21 versus 63 +/- 24 ms; P < .005) and increased with TIMI grade 3 flow (LF, 5.3 +/- 1.0 versus 4.8 +/- 1.2 ms2; P < .01) and better ejection fraction (r = .2, P < .03). An inverse correlation between the duration of ST shift and frequency domain measures was observed (LF, r = -.2, P < .009; HF, r = -2, P < .03). Lower LF/HF ratio by 24 hours after myocardial infarction was seen in those who ultimately died at 30 days (1.0 +/- 0.2 versus 1.3 +/- 0.2, P < .001) or at 1 year (1.17 +/- 0.14 versus 1.26 +/- 0.19, P = .05).

CONCLUSIONS

Changes in heart rate variability occurred early after thrombolysis and may be of prognostic value. Heart rate variability measures were improved in patients with better ejection fraction and greater angiographic patency. This suggests a possible mechanism for the enhanced survival observed with TIMI grade 3 flow in the GUSTO angiographic substudy. These data indicate that early heart rate variability assessment after myocardial infarction may be useful in noninvasive risk stratification.

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

BACKGROUND

There are few data comparing clinical outcome and potential indications for routine post-myocardial infarction cardiac catheterization and revascularization of patients who sustain a non-Q-wave versus Q-wave infarct after thrombolytic therapy.

METHODS AND RESULTS

A secondary analysis of 2634 patients enrolled in the TIMI II trial with a first myocardial infarction was performed to determine 6-week and 1-year cardiac event rates and identify clinical and angiographic differences between the 1867 patients (70.9%) who evolved a Q-wave infarct and the 767 patients (29.1%) who sustained a non-Q-wave infarct after treatment with intravenous thrombolytic therapy. Male sex (85.3% versus 75.6%; P < .001) and anterior wall infarcts (53.8% versus 43.7%; P < .001) were more frequent in the Q-wave versus the non-Q-wave group. During recombinant tissue-type plasminogen activator (rTPA) infusion, a greater percentage of non-Q-wave patients (37.3% versus 23.5%; P = .001) had normalization of initial ST-segment elevation. Infarct-related artery patency (TIMI flow grade 2 or 3) (P = .02), complete infarct-related artery reperfusion (TIMI 3 flow grade) (P < .001), and the percentage of patients with a predischarge resting left ventricular ejection fraction > 55% (P < .001) were greater in the non-Q-wave group. New congestive heart failure during hospitalization developed more frequently in Q-wave patients (18.9% versus 11.6%; P < .001). After 42 days, the occurrences of reinfarction (P = .76), death (P = .76), and combined death or reinfarction (P = .43) were similar in patients assigned to the invasive or conservative postlytic management strategy, regardless of infarct type. One-year mortality was 3.4% versus 4.4% for non-Q-wave versus Q-wave infarct type, respectively (P = .25).

CONCLUSIONS

Angiographic and clinical differences were observed between patients who present with initial ST-segment elevation and evolve early non-Q-wave versus Q-wave myocardial infarcts after treatment with rTPA, heparin, and aspirin. Early mortality and adverse clinical cardiac events in these patients are not significantly different after a conservative compared with an invasive treatment strategy, regardless of whether the infarct type is non-Q wave or Q wave.

Doppler guide wire flow-velocity indexes measured distal to coronary stenoses associated with reversible thallium perfusion defects

A Doppler guide wire was used to measure phasic coronary blood flow velocity distal to coronary stenoses in 17 symptomatic patients with corresponding positive exercise or adenosine thallium scintigrams. Distal average peak velocity and diastolic/systolic flow-velocity ratio were obtained in 16 vessels with stenoses (55% to 85% diameter stenosis) and a corresponding reversible thallium defect and in 11 control vessels with no stenosis or thallium defect. Coronary flow-velocity reserve was obtained with intracoronary adenosine. Coronary flow reserve (2.3 +/- 0.4 vs 1.2 +/- 0.3, p < 0.01) and diastolic/systolic flow-velocity ratio (1.95 +/- 0.56 vs 1.44 +/- 0.59, p < 0.04) were significantly different between normal vessels and distal to stenoses, respectively. Excellent concordance between distal coronary flow reserve and diastolic/systolic flow-velocity ratio to thallium scintigraphy was noted. A coronary flow reserve of < 1.8 and a diastolic/systolic flow-velocity ratio of < 1.7 predicted a reversible thallium perfusion scintigram (concordance 96% and 88%, respectively). Distal coronary flow velocity indexes may provide an alternative means of physiologic assessment of lesion severity during coronary angiography.

Coronary artery bypass graft surgery after thrombolytic therapy in the Thrombolysis in Myocardial Infarction Trial, Phase II (TIMI II)

OBJECTIVES

We examined the results of coronary artery bypass graft surgery after thrombolytic therapy in the Thrombolysis in Myocardial Infarction trial, Phase II (TIMI II) with particular emphasis on patient characteristics, the impact of antecedent percutaneous transluminal coronary angioplasty and morbidity and mortality in certain subgroups.

BACKGROUND

Coronary bypass surgery is frequently used after thrombolytic therapy, but there is relatively little information with regard to early and late outcomes.

METHODS

We analyzed 3,339 patients enrolled in the TIMI II trial. Bypass surgery was performed in 390 patients (11.7%): 54 (14%) within 24 h after entry into the trial or within 24 h of coronary angioplasty and 336 (86%) between 24 h and 42 days after entry.

RESULTS

Perioperative mortality rates were, respectively, 16.7% and 3.9% (p < 0.001); perioperative myocardial infarction rates were 5.6% and 6.2%, respectively; and major hemorrhagic events occurred in 74% and 50.9%, respectively (p = 0.002). On multivariate analysis, the only independent predictor of perioperative mortality was bypass surgery within 24 h after entry or after coronary angioplasty. Among patients undergoing bypass surgery within 24 h of entry or after coronary angioplasty, the prevalence of multivessel disease (59.1% vs. 77.8%) and use of the internal thoracic artery (18.5% vs. 62.5%) were lower than in the remaining surgical patients. Among the 322 perioperative survivors, the 1-year mortality rate after discharge was only 2.2% and 1.9%, respectively, in the two groups. Only one patient had a documented recurrent myocardial infarction during the first year.

CONCLUSIONS

The increased mortality rate with bypass surgery after thrombolytic therapy, particularly in patients undergoing operation within 24 h of coronary angioplasty or during the involving phase of infarction, must be balanced against the excellent 1-year prognosis and perioperative survivors, who are in general a group at higher risk of death or recurrent infarction. These data provide a basis for comparison for future studies.

Mortality within 24 hours of thrombolysis for myocardial infarction. The importance of early reperfusion. The GUSTO Investigators, Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries

BACKGROUND

A paradoxical increased risk of death has been reported during the first 24 hours after thrombolysis for myocardial infarction. The mechanism of this phenomenon is not known, nor is its relation to the success or failure of reperfusion. The present study was a prospectively designed analysis of deaths occurring within the first 24 hours in the GUSTO trial.

METHODS AND RESULTS

There were 41,021 patients enrolled in GUSTO, a randomized comparison of streptokinase with intravenous or subcutaneous heparin, accelerated tissue-type plasminogen activator (TPA), and combination of streptokinase and TPA. An angiographic mechanistic substudy examined reperfusion (using the TIMI flow grading criteria) 90 minutes after the assigned thrombolytic regimen was begun in 1567 patients. There were 1125 deaths (2.8%) within 24 hours ("early deaths") and 1726 additional deaths (4.2%) after 24 hours but within 30 days ("later deaths"). At the time of presentation, the most potent predictors of early death were hypotension and sinus tachycardia. In a multiple logistic regression model, lower systolic blood pressure, shorter height, higher heart rate, and the absence of prior smoking distinguished early death from later death. Reinfarction occurred in 26 patients (2.4%), shock in 572 patients (52%), atrioventricular block in 308 patients (28%), and tamponade in 106 patients (10%) dying early compared with 262 (15%), 788 (46%), 396 (23%), and 74 (4%) respective patients dying later. There were no differences in early mortality among the thrombolytic regimens for the first 6 hours after randomization. By 24 hours, however, mortality was 2.89% for streptokinase recipients, 2.84% for combination therapy recipients, and 2.36% for accelerated TPA recipients (P = .005). There was little difference among patients with differing flow grades in the infarct artery during the first 4 hours, although mortality was 2.35% for patients with flow grade 0 or 1, 2.92% for patients with flow grade 2, and 0.89% for patients with flow grade 3.

CONCLUSIONS

Even with aggressive management regimens, mortality within the first 24 hours accounted for a large proportion of postthrombolytic deaths. Patients dying early were more likely to present with pump failure than were those dying later and were more likely to diet of events related to left ventricular dysfunction, although cardiac tamponade also accounted for a significant minority of these deaths. Thus, the severity of the clinical presentation rather than the underlying risk factors predicts early mortality. Based on the angiographic substudy data, it appears that rather than hastening early mortality, successful restoration of complete antegrade flow in the infarct-related artery protects against early death.

Bedside monitoring of heparin therapy: comparison of activated clotting time to activated partial thromboplastin time

Heparin anticoagulation is utilized during and after interventional cardiac catheterization procedures to reduce the risk of acute thrombotic coronary artery occlusion. The short half-life of heparin, the importance of maintaining therapeutic anticoagulation, and the time delay inherent in the processing and retrieval of the activated partial thromboplastin time (aPTT) by the hospital laboratory has generated interest in point-of-care heparin monitoring. The activated clotting time (ACT), the aPTT as assessed by both a new portable device, as well as the hospital laboratory, and heparin levels (H) were obtained from the same sample of blood in 100 patients receiving intravenous heparin. There was an excellent correlation between the aPTT determined at the bedside and by the hospital laboratory (r = .89). The ACT did not correlate well with either the laboratory or bedside aPTT (r = .63, .68 respectively). In the sub-therapeutic and therapeutic range, there was essentially no correlation between ACT and H. Only ACT values > 225 sec were predictive of therapeutic or supra-therapeutic aPTTs. ACT values < 225 sec, however, were not useful in predicting degree of anticoagulation. In situations in which the maintenance of therapeutic anticoagulation is critical as well as those in which the determination of lack of anticoagulation is required, the bedside determination of aPTT appears to be a useful tool.

Incidence of allergic rhinitis in general practice, 1981-92

OBJECTIVES

To determine the epidemiology of hay fever and to consider the role of pollution.

DESIGN

Examination of data on weekly incidence of allergic rhinitis and hay fever by age, sex, region, and location.

SETTING

Royal College of General Practitioners Weekly Returns Service. Practice data were based on registered populations of 220,000 in 1981, rising to 700,000 in 1992 from England and Wales.

MAIN OUTCOME MEASURES

Numbers of new cases of hay fever and allergic rhinitis. Data on pollen counts for Darlington, Derby, and London.

RESULTS

The incidence of allergic rhinitis fluctuated greatly from year to year but showed no trend. Peaks in hay fever coincided with peak pollen counts. No important differences were found between urban and rural locations or different parts of the country with respect to both size and timing of the peaks. Incidence was highest in children (5-14 years).

CONCLUSIONS

The similarity of the results throughout England and Wales does not support an important role for local pollutants in hay fever. However, the possibility that levels of pollutants are high enough to act as an adjuvant in hay fever across the whole study area has not been excluded.

Ventricular free wall and septal rupture (double rupture): a "pseudocomplication" during post-infarction laser angioplasty

We report the rare occurrence of double rupture of the myocardium occurring immediately following successful laser recanalization of an occluded right coronary artery in a 72-year-old woman 5 days following infero-posterior myocardial infarction.

Anistreplase versus alteplase in acute myocardial infarction: comparative effects on left ventricular function, morbidity and 1-day coronary artery patency. The TEAM-3 Investigators

OBJECTIVES

This double-blind, randomized, multicenter trial was designed to compare the effects of treatment with anistreplase (APSAC) and alteplase (rt-PA) on convalescent left ventricular function, morbidity and coronary artery patency at 1 day in patients with acute myocardial infarction.

BACKGROUND

Anistreplase (APSAC) is a new, easily administered thrombolytic agent recently approved for treatment of acute myocardial infarction. Alteplase (rt-PA) is a rapidly acting, relatively fibrin-specific thrombolytic agent that is currently the most widely used agent in the United States.

METHODS

Study entry requirements were age less than or equal to 75 years, symptom duration less than or equal to 4 h, ST segment elevation and no contraindications. The two study drugs, APSAC, 30 U/2 to 5 min, and rt-PA, 100 mg/3 h, were each given with aspirin (160 mg/day) and intravenous heparin. Prespecified end points were convalescent left ventricular function (rest/exercise), clinical morbidity and coronary artery patency at 1 day. A total of 325 patients were entered, stratified into groups with anterior (37%) or inferior or other (63%) acute myocardial infarction, randomized to receive APSAC or rt-PA and followed up for 1 month.

RESULTS

At entry, patient characteristics in the two groups were balanced. Convalescent ejection fraction at the predischarge study averaged 51.3% in the APSAC group and 54.2% in the rt-PA group (p less than 0.05); at 1 month, ejection fraction averaged 50.2% versus 54.8%, respectively (p less than 0.01). In contrast, ejection fraction showed similar augmentation with exercise at 1 month after APSAC (+4.3% points) and rt-PA (+4.6% points), and exercise times were comparable. Coronary artery patency at 1 day was high and similar in both groups (APSAC 89%, rt-PA 86%). Mortality (APSAC 6.2%, rt-PA 7.9%) and the incidence of other serious clinical events, including stroke, ventricular tachycardia, ventricular fibrillation, heart failure within 1 month, recurrent ischemia and reinfarction were comparable in the two groups; and mechanical interventions were applied with equal frequency. A combined clinical morbidity index was determined and showed a comparable overall outcome for the two treatments.

CONCLUSIONS

Convalescent rest ejection fraction was high after both therapies but higher after rt-PA; other clinical outcomes, including exercise function, morbidity index, and 1-day coronary artery patency, were favorable and comparable after APSAC and rt-PA.

Heparin-induced prolongation of partial thromboplastin time after thrombolysis: relation to coronary artery patency. HART Investigators

Having previously shown in the Heparin Aspirin Reperfusion Trial that the empiric use of early intravenous heparin after recombinant tissue-type plasminogen activator (rt-PA) is an important component in the overall treatment strategy, we examine in this report the specific relation between the degree of prolongation of activated partial thromboplastin time and coronary artery patency. To evaluate the hypothesis that arterial patency after administration of rt-PA for acute myocardial infarction is sustained by effective anticoagulation, activated partial thromboplastin time of heparin recipients was determined 8 and 12 h after the start of thrombolysis. Mean activated partial thromboplastin time was higher among patients with an open infarct-related artery than in those with a closed artery (81 +/- 4 vs. 54 +/- 9 s, p less than 0.02). Only 45% of patients with values less than 45 s at both 8 and 12 h had Thrombolysis in Myocardial Infarction (TIMI) flow grade 2 or 3 in the infarct-related artery at 18 h. In contrast, 88% of patients with activated partial thromboplastin time greater than 45 s and 95% of those with values greater than 60 s had an open infarct-related artery at 18 h (p = 0.003 and 0.0006, respectively). Among patients with an initially patent infarct-related artery who underwent repeat angiography at 7 days, activated partial thromboplastin time was similar in those with a persistently patent artery and those with late reocclusion. Excessive anticoagulation did not appear to increase hemorrhagic risk except that access site-related hemorrhage was more common in patients with activated partial thromboplastin time greater than 100 s at 8 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Prognosticators of outcome after major head injury in the elderly

In 195 elderly head-injured patients, Glasgow Coma Scale (GCS) scores (admission and 72 hours) and intracranial pressure (ICP) 0-12 days after injury were compared to 6 month Glasgow Outcome Scores. All patients remaining comatose at least 72 hours after injury died within 6 months. The mortality rate among patients with ICP greater than 20 mm Hg was higher both at 72 hours and at 6 months after injury. The 6 month mortality rate was 75% overall and 90% among patients with elevated ICP. This increased mortality in elderly patients with initially elevated ICP indicates that nurses and other health professionals should consider ICP as well as level of consciousness when counseling patients and families regarding the likely outcome after major head injuries.

Importance of myocardial infarct artery patency on the prevalence of ventricular arrhythmia and late potentials after thrombolysis in acute myocardial infarction

Sustained infarct artery patency is an important determinant of survival in patients with acute myocardial infarction. We studied 61 patients with acute myocardial infarction who received intravenous recombinant tissue-type plasminogen activator, aspirin or heparin within 6 hours of symptom onset, to determine if infarct artery patency after intravenous thrombolytic therapy influences myocardial electrical stability as measured by the prevalence of spontaneous ventricular ectopy or late potential activity. Infarct artery patency was determined by angiographic evaluation 2.5 +/- 3 days after infarction. Forty-eight patients (79%) had a patent infarct-related artery and 13 (21%) patients had an occluded vessel. The mean number of ventricular premature complexes (VPCs)/hour (p less than 0.01) and the prevalence of late potentials (54 vs 19%; p less than 0.03) were significantly higher in patients with an occluded versus patent-infarct related vessel. Although VPC frequency and late potentials were not influenced by the time to thrombolytic treatment, patients with a patent infarct-related artery had a lower prevalence of late potentials regardless of whether treatment was initiated less than or equal to 2 hours (25% patent vs 50% occluded; p = not significant) or 2 to 6 hours (16% patent vs 55% occluded; p greater than 0.03) after symptom onset. Thus, successful thrombolysis decreases the frequency of ventricular ectopic activity and late potentials in the early postinfarction phase. The reduction in both markers of electrical instability may help explain why the prognosis after successful thrombolysis is improved after acute myocardial infarction.

Cardiac myocytes and dendritic cells harbor human immunodeficiency virus in infected patients with and without cardiac dysfunction: detection by multiplex, nested, polymerase chain reaction in individually microdissected cells from right ventricular endomyocardial biopsy tissue

Two hundred fifteen patients infected with human immunodeficiency virus (HIV) participated in a prospective longitudinal study of HIV-related heart disease. Evaluation included signal-averaged electrocardiography and echocardiography. Fifteen patients underwent endomyocardial biopsy, 5 had cardiovascular symptoms and 10 did not. Cardiac myocytes or dendritic cells were prepared by individual cell microdissection to sort them from other cell types such as interstitial cells or circulating blood elements. HIV proviral sequences were amplified in samples of 15 to 20 cells of each type by multiplex, nested, polymerase chain reaction and hybridized to 32P-labeled probes specific for regions within the gag and pol genes of HIV-1. The results showed the presence of HIV sequences in myocytes of 2 of 5 patients with cardiac symptoms and in 6 of 10 without. Thus, symptomatic HIV cardiomyopathy did not appear to be a direct consequence of the virus on myocardial cells. In dendritic cells, HIV sequences were detected in 5 of 5 patients with cardiac symptoms and in 8 of 10 with apparently normal ventricular function. Furthermore, dendritic cells were somewhat more numerous in the myocardium of symptomatic than asymptomatic patients. Our studies are the first to directly detect the HIV genome in purified cardiac myocytes from patients with and without cardiac dysfunction. Our findings do not support a direct role of the virus in myocardial dysfunction. However, the results do suggest that the interstitial dendritic cells may be involved in some manner in the development of cardiac dysfunction observed in HIV-infected patients.

The role of coronary angioplasty in the management of unstable angina pectoris

Using percutaneous transluminal coronary angioplasty (PTCA) as primary therapy for unstable angina is quite common. Unstable angina appears to be the indication for the procedure in approximately one third of all PTCA attempts. Considering the unstable nature of the plaque in this type of angina, and the increased risk of abrupt occlusion due to frequent intraluminal thrombus, the generally reported rate of success, approximately 85%, is highly respectable. The evidence supporting a period of pretreatment with aspirin and heparin is strong. Less certain is the value of concomitantly administering plasminogen activators. Pending data should produce important further guidelines for effective therapy. Major trials, some using fibrinolytics as well as taking an overall aggressive, interventional approach (like that taken by UNSA, TIMI-III, and others), are reaching the recruitment-completion and promulgation stages.