Randomized comparison of enoxaparin, a low-molecular-weight heparin, with unfractionated heparin adjunctive to recombinant tissue plasminogen activator thrombolysis and aspirin: second trial of Heparin and Aspirin Reperfusion Therapy (HART II)

BACKGROUND

Adjunctive unfractionated heparin (UFH) during thrombolytic therapy for acute myocardial infarction (AMI) promotes the speed and magnitude of coronary artery recanalization and reduces reocclusion. Low-molecular-weight heparins offer practical and potential pharmacological advantages over UFH in multiple applications but have not been systematically studied as adjuncts to fibrinolysis in AMI.

METHODS AND RESULTS

Four hundred patients undergoing reperfusion therapy with an accelerated recombinant tissue plasminogen activator regimen and aspirin for AMI were randomly assigned to receive adjunctive therapy for at least 3 days with either enoxaparin or UFH. The study was designed to show noninferiority of enoxaparin versus UFH with regard to infarct-related artery patency. Ninety minutes after starting therapy, patency rates (thrombolysis in myocardial infarction [TIMI] flow grade 2 or 3) were 80.1% and 75.1% in the enoxaparin and UFH groups, respectively. Reocclusion at 5 to 7 days from TIMI grade 2 or 3 to TIMI 0 or 1 flow and TIMI grade 3 to TIMI 0 or 1 flow, respectively, occurred in 5.9% and 3.1% of the enoxaparin group versus 9.8% and 9.1% in the UFH group. Adverse events occurred with similar frequency in both treatment groups.

CONCLUSIONS

Enoxaparin was at least as effective as UFH as an adjunct to thrombolysis, with a trend toward higher recanalization rates and less reocclusion at 5 to 7 days.

A randomized trial confirming the efficacy of reduced dose recombinant tissue plasminogen activator in a Chinese myocardial infarction population and demonstrating superiority to usual dose urokinase: the TUCC trial

BACKGROUND

Reports from Japan suggest effective myocardial infarction (MI) treatment in Asian patients with much lower doses of tissue plasminogen activators (tPA) than used in European and American regimens. Because increasing doses of fibrinolytics lead to increased bleeding complications, identification of patients who respond to reduced doses is of importance. We conducted a trial in the People's Republic of China in which reduced-dose recombinant tPA was compared with the standard local therapy, urokinase.

METHODS

Four hundred patients with acute MI within 12 hours of symptom onset were to be randomized to an 8-mg bolus of recombinant tPA followed by a 42-mg 90-minute infusion or 1.5 million units of urokinase as a 30-minute infusion. Patients received aspirin and heparin and underwent angiography to determine infarct artery patency 90 minutes after the start of therapy.

RESULTS

The Data and Safety Monitoring Board recommended premature termination after 342 patients were recruited. Infarct artery patency (grade 2 or 3) occurred in 79% of patients receiving recombinant tPA and in 53% of patients receiving urokinase (P <.001); Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow was 48% and 28%, respectively (P <.001). The higher-patency-rate recombinant tPA growth had better posttreatment left ventricular ejection fractions, 58.6% versus 54.7%, P <.01. Adverse events were infrequent and not significantly different in the 2 groups.

CONCLUSIONS

This study confirms that a substantially lower dose of recombinant tPA is effective in Asian patients compared with that required in Western patients even after consideration of body weight. Specific dose-response studies should be performed with fibrinolytic regimens to avoid overdosage with its attendant risks of excess bleeding.

Predictors of left ventricular function after acute myocardial infarction: effects of time to treatment, patency, and body mass index: the GUSTO-I angiographic experience

BACKGROUND

Despite the significant survival benefit associated with successful reperfusion therapy for acute myocardial infarction, global indices of outcome left ventricular function, such as ejection fraction, have often demonstrated little or no improvement. Although these measurements are confounded by numerous clinical, physiologic, and angiographic variables, no comprehensive analysis of this issue in a large series of patients is available. We used the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-I) database to better understand this phenomenon by determining independent predictors of left ventricular function and their interplay with regard to outcome ventricular function and improvement in function during the initial postinfarction week.

METHODS

Ninety-minute and 5- to 7-day posttreatment global and regional indices derived from left ventriculograms were analyzed from a population of 676 patients. These observations were combined with clinical data to describe independent determinants of ventricular function outcome.

RESULTS

Clinical factors predictive of global and regional ventricular function as well as improvement in function between 90 minutes and 5 to 7 days included time to treatment, early infarct-related artery flow grade, and body mass index. These same factors contribute significantly to compensatory hyperkinesis of the noninfarct zone, which is critical to maintenance of global ventricular function during this time period.

CONCLUSIONS

The ventricular function benefits of early complete reperfusion after myocardial infarction are readily demonstrable after adjustment for multiple covariables and include (1) maintenance of global ventricular function and (2) prevention or delay in ventricular dilatation.

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.

Health professional students' occupational exposures to blood-borne pathogens: primary and secondary prevention strategies

Health science students, along with the health professionals they hope to become, are at increased risk for certain occupational injuries and illnesses. One of these risks is occupational exposure to blood-borne pathogens, such as human immunodeficiency virus (HIV) and hepatitis, which may result in severe illnesses or even death. Two case studies demonstrate postexposure care of exposed individuals at the University of Texas Medical Branch Student Health Services before and after policy changes and prevention strategies were strengthened in response to exposure incidents.

Presentation with influenza-like illness in general practice: implications for use of neuraminidase inhibitors

General practitioners in the Midlands Research Practice Consortium (MidReC), combined list size 140,000, completed questionnaires about 918 patients in whom they had made working diagnoses of influenza-like illness during an outbreak of influenza A H3N2 from 1 December 1999 to 4 February 2000. Adults, more females than males consulted most, reflecting the age and sex distribution reported to the Royal College of General Practitioners Weekly Returns Service. Illness at presentation was considered severe in 4%, moderately severe in 49%, mild in 45%, and asymptomatic (for example, attended for certificates) in 1% of patients. In seven tenths of patients, the practitioner estimated that the likelihood of influenza was 70% or more and in just over half, 80% or more. Half of patients aged over 75 years were seen at home, but only 7% of those under 55 years. Less than a quarter of patients consulted within two days of having become ill, with the highest consultation frequency on the third and fourth days. Preschool children presented earliest: 75% were seen within two days, compared with only 17% of adults over 75 years. Four fifths of patients were seen on the same day as they contacted the practice, and 12% on the following day. Given the brief time window for effective antiviral treatment, only a small proportion of patients are likely to be prescribed these drugs unless consulting behaviour, especially in elderly people, changes considerably.

Use of whole blood specimens for routine clinical quantitation of hepatitis C virus RNA does not increase assay sensitivity

The measurement of hepatitis C virus (HCV) RNA levels in the blood has, in the last few years, become a critical component in the therapy of patients with HCV infections. Initially, extraction methods for serum and plasma were used, but a newer method that uses Catrimox-14 as the extraction agent for whole blood has been reported. Because the whole blood extraction method may yield higher virus levels if significant levels of virus are present in the white blood cells (WBC), the method was evaluated for use in our clinical diagnostic laboratory despite its higher reagent costs and more time-consuming methodology. RNA was simultaneously extracted from 39 clinical samples by four different methods: Catrimox-14-Trizol extraction from whole blood, Trizol extraction from whole blood, Trizol extraction from serum, and a commercial serum extraction method, the EZNA total RNA kit. In addition, in an effort to quantitate the amount of HCV RNA virus in the WBC, Trizol extraction from isolated WBC was also performed. Quantitative results for samples from which RNA was extracted by all four methods were essentially the same; the Catrimox-14-Trizol method did not yield increased virus levels. Insignificant levels of virus were found in the WBC. The results did not demonstrate a clinical usefulness for the Catrimox-14-Trizol method.

Relationship of infarct artery patency and left ventricular ejection fraction to health-related quality of life after myocardial infarction: the GUSTO-I Angiographic Study experience

BACKGROUND

Post-myocardial infarction global ejection fraction and infarct-related artery patency might be expected to be associated with health-related quality-of-life (HRQOL) outcomes, but this association has not been previously shown. The GUSTO-I Angiographic Study cohort 2-year follow-up afforded an examination of such potential relationships.

METHODS AND RESULTS

A total of 1848 patients (87.7% response rate) who were enrolled in the GUSTO-I Angiographic Study were contacted for a telephone interview regarding their current HRQOL (physical function, psychological well-being, perceived health status, and social function) 2 years after MI. In multivariable models, left ventricular ejection fraction (EF) was significantly related to physical (P:=0.021) and social (P:=0.014) function, psychological well-being (P:=0.042), and perceived health status (P:=0.024). Infarct-related artery patency was not directly related to any HRQOL outcome. A decreasing EF was predictive of poorer outcomes in each HRQOL dimension. Men consistently had better outcomes in all HRQOL dimension with the exception of perceived health status. Increasing age was predictive of poorer outcomes in all dimensions of HRQOL except for psychological well-being where the inverse occurred; younger patients experienced greater depression, anxiety and worry than their older counterparts. The presence of comorbidities increased the likelihood of worse outcomes in all dimensions.

CONCLUSIONS

This is the first study to demonstrate a significant relationship between EF and long-term HRQOL outcomes. This advantage in left ventricular function preservation should be added to the mortality advantage when considering the impact of treatment strategies for myocardial infarction.

Chickenpox increasingly affects preschool children

Between 1983 and 1998, age specific incidences of chickenpox derived from consultations with general practitioners taking part in the Royal College of General Practitioners Weekly Returns Service doubled in children aged 0 to 4 years, halved in children aged 5 to 14 years, and fell by almost a third in adults aged 15 to 44 years. This downward shift in age of contracting chickenpox may be a result of increased social contact between preschool children.

Declining incidence of episodes of asthma: a study of trends in new episodes presenting to general practitioners in the period 1989-98

BACKGROUND

A study was undertaken to determine trends in the incidence of new episodes of asthma presented to general practitioners participating in the Weekly Returns Service of the Royal College of General Practitioners, comprising 92 practices with a registered population of approximately 680 000 persons well distributed throughout England and Wales. These practices monitor the morbidity presented at every consultation, distinguishing between new episodes of illness and ongoing consultations.

METHODS

Age specific weekly rates of new episodes of asthma (and of acute bronchitis) presenting to the general practitioners over the years 1989-98 were examined in four week blocks and analysed by multiple regression, separating secular from seasonal trends.

RESULTS

Quadratic trends in episodes of asthma were evident in each of the age groups with peaks in 1993/4. Corresponding analyses for acute bronchitis disclosed similar trends generally peaking in the winter of 1993/4. Mean weekly incidence data (all ages combined) decreased in all quarters since 1993. Regional analysis (North/Central/South) showed similar decreases.

CONCLUSIONS

There has been a gradual decrease in the incidence of asthma episodes and of acute bronchitis presenting to general practitioners since 1993. The trend of an increase before 1993 followed by a decrease cannot be explained by changes in the patterns of health care usage or diagnostic preference of doctors.

Comparison of the seasonal patterns of asthma identified in general practitioner episodes, hospital admissions, and deaths

BACKGROUND

Seasonal variations in asthma are widely recognised. This study was undertaken to investigate the relative differences in seasonal patterns by age as they impact on episodes of care in general practice, hospital admissions, and deaths.

METHODS

General practice episode data from the Weekly Returns Service of the Royal College of General Practitioners, hospital admissions for asthma in England, and deaths registered as due to asthma in England and Wales over the years 1990-7 were examined. Age specific weekly rates of new episodes of asthma presenting to general practitioners, numbers of hospital admissions and deaths were analysed by the multiplicative decomposition method to separate secular from seasonal trends. The seasonal indices thereby obtained were plotted as three week moving averages.

RESULTS

In children aged 0-4 and 5-14 years general practice episodes and admissions to hospital were strikingly congruent in timing and in magnitude, except in September when particularly high rates of admission (absolute and relative to general practice episodes) occurred. In the 15-44 age group there were marked mid summer peaks of general practice episodes and deaths but admissions to hospital were at about the annual average; in September/October there were peaks of episodes and admissions whereas deaths peaked in November. In the 45-64 age group a peak in general practice episodes of asthma was evident in mid summer when admissions were about average and deaths were at a minimum; all three measures tended to increase gradually with the approach of winter. Finally, in those age over 65 years, general practice episodes of asthma, admissions to hospital, and deaths followed similar 'U' shaped patterns with substantial peaks in mid winter.

CONCLUSIONS

The seasonal pattern of asthma evolves with age. There are important differences in the seasonal pattern of general practice episodes, admissions to hospital, and deaths. Individual seasonal histories are important for the management of asthma. The combined analysis of these three data sets provides a new perspective on the epidemiology of asthma.

A randomized trial comparing primary angioplasty with a strategy of short-acting thrombolysis and immediate planned rescue angioplasty in acute myocardial infarction: the PACT trial. PACT investigators. Plasminogen-activator Angioplasty Compatibility Trial

OBJECTIVES

The study evaluated the efficacy and safety of a short-acting reduced-dose fibrinolytic regimen to promote early infarct-related artery (IRA) patency during the inherent delay experienced by infarct patients referred for angioplasty as the principal recanalization modality.

BACKGROUND

Previous approaches using long-acting, full-dose thrombolytic infusions rarely showed benefit, but they did increase adverse event rates.

METHODS

Following aspirin and heparin, 606 patients were randomized to a 50-mg bolus of recombinant tissue-type plasminogen activator (rt-PA) (alpha half-life 4.5 min) or to placebo followed by immediate angiography with angioplasty if needed. The end points included patency rates on catheterization laboratory (cath lab) arrival, technical results when PTCA (percutaneous transluminal coronary angioplasty) was performed, complication rates, and left ventricular (LV) function by treatment assignment and time to restored patency following angioplasty.

RESULTS

Patency on cath lab arrival was 61% with rt-PA (28% Thrombolysis in Myocardial Infarction trial [TIMI]-2, 33% TIMI-3), and 34% with placebo (19% TIMI-2, 15% TIMI-3) (p = 0.001). Rescue and primary PTCA restored TIMI-3 in closed arteries equally (77%, 79%). No differences were observed in stroke or major bleeding. Left ventricular function was similar in both treatment groups, but convalescent ejection fraction (EF) was highest with a patent IRA (TIMI-3) on cath lab arrival (62.4%) or when produced by angioplasty within an hour of bolus (62.5%). However, in 88% of angioplasties, the delay exceeded 1 h: convalescent EF 57.3%.

CONCLUSIONS

Tailored thrombolytic regimens compatible with subsequent interventions lead to more frequent early recanalization (before cath arrival), which facilitates greater LV function preservation with no augmentation of adverse events.

New plasminogen activators: a clinical review

Rapid restoration of patency of the infarct-related artery is the key to preserving myocardium and improving survival. This understanding has led to the application of genetic engineering to develop new plasminogen activators with specific clinical features. These novel activators may provide faster and more complete reperfusion in a greater number of patients, and do so with less risk of bleeding and intracranial hemorrhage. This article reviews the pharmacologic profiles and clinical performance of several novel plasminogen activators engineered from the human tissue plasminogen activator molecule or developed from animal and bacterial proteins.

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.

Clinical predictors of early infarct-related artery patency following thrombolytic therapy: importance of body weight, smoking history, infarct-related artery and choice of thrombolytic regimen: the GUSTO-I experience. Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries

OBJECTIVES

The purpose of this study was to determine patient characteristics that are a priori predictors of early infarct related artery patency following thrombolytic therapy, and to provide a paradigm which may identify patients who would be most likely to achieve restoration of normal (TIMI 3) coronary flow in response to thrombolytic therapy.

BACKGROUND

Restoration of infarct-related artery perfusion in acute myocardial infarction is necessary for preservation of ventricular function and mortality reduction. Clinical variables that are a priori predictors of early patency with currently available thrombolytic regimens have not been fully characterized.

METHODS

The probability of early infarct-related artery patency (TIMI 3 flow) was determined by multivariable logistic regression. We determined a reduced (parsimonious) model for predicting early (90 min) infarct-related artery patency (TIMI grade 3) based on data from 1,030 patients in the GUSTO-I Angiographic study.

RESULTS

Predictors of 90 min TIMI 3 flow are use of an accelerated t-PA regimen (vs. streptokinase containing regimens) (chi2=39.1; p < or = 0.0001), infarct related artery (RCA/Lcx vs. LAD) (chi2=12.7; p=0.0004), body weight (chi2=10.3; p=0.001) and history of smoking (chi2=7.4; p=0.007). Time from symptom onset to treatment was not significant (p=0.71).

CONCLUSIONS

The efficacy of currently available thrombolytic regimens is chiefly dependent on choice of thrombolytic regimen, body weight, infarct-related coronary artery and smoking history. Clinical variables alone correctly predict a priori TIMI 3 flow in the infarct-related artery 64% of the time. Patients with body weights greater than 85 kg are at a significant disadvantage with regard to achieving successful thrombolysis compared to those with lesser body weights.

Rescue angioplasty after failed thrombolysis: technical and clinical outcomes in a large thrombolysis trial. GUSTO-1 Angiographic Investigators. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries

OBJECTIVES

We sought to assess the angiographic outcome, complication rates and clinical features of percutaneous transluminal coronary angioplasty (PTCA) after failed thrombolysis for acute myocardial infarction.

BACKGROUND

"Rescue angioplasty" refers to mechanical reopening of an occluded infarct-related artery (IRA) after failed intravenous thrombolysis. Although the procedure is commonly performed, data describing its technical and clinical outcome are sparse. Early reports suggested that rescue PTCA is less often successful and produces more complications than primary PTCA. Other reports have described beneficial effects of successful rescue PTCA but adverse outcomes when PTCA is unsuccessful.

METHODS

Using data from the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO-1) angiographic substudy, we compared clinical and angiographic outcomes of 198 patients selected for a rescue PTCA attempt with those of 266 patients with failed thrombolysis but managed conservatively and, for reference, with those of 1,058 patients with successful thrombolysis.

RESULTS

Patients offered rescue PTCA had more impaired left ventricular function than those in whom closed vessels were managed conservatively. Rescue successfully opened 88.4% of closed arteries, with 68% attaining Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow. The interventions did not increase catheterization laboratory or postprocedural complication rates. Multivariate analysis identified severe heart failure to be a determinant of a failed rescue attempt. Successful rescue PTCA resulted in superior left ventricular function and 30-day mortality outcomes, comparable to outcomes in patients with closed IRAs managed conservatively, but less favorable than in patients in whom thrombolytic therapy was initially successful. The mortality rate after a failed rescue attempt was 30.4%; however, five of the seven patients who died after failed rescue PTCA were in cardiogenic shock before the procedure.

CONCLUSIONS

Rescue PTCA tends to be selected for patients with clinical predictors of a poor outcome. It is effective in restoring patency. Patients who die after a failed rescue attempt are often already in extremis before the angioplasty attempt.

Extended mortality benefit of early postinfarction reperfusion. GUSTO-I Angiographic Investigators. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries Trial

BACKGROUND

Reperfusion therapy for myocardial infarction, understood to reduce mortality by preserving left ventricular function, was initially expected to provide increasing benefits over time. Surprisingly, large controlled thrombolysis trials demonstrated maximum benefit at 4 to 6 weeks with no subsequent increased treatment advantage. Such studies, however, compared groups by assigned treatment, not physiological effectiveness.

METHODS AND RESULTS

We calculated 2-year survival differences among 2431 myocardial infarction patients according to early infarct artery patency and outcome left ventricular ejection fraction using Kaplan-Meier curves. Hazard ratios for significant survival determinants were derived from Cox regression models. Two-year vital status (minimum, 688 days) was determined in 2375 patients (97.7%). A substantial mortality advantage for early complete reperfusion (Thrombolysis in Myocardial Infarction [TIMI] grade 3) and for preserved ejection fraction occurred beyond 30 days. The unadjusted hazard ratio for the TIMI 3 group compared with lesser grades at 30 days was 0.57 (95% confidence interval [CI], 0.35 to 0.94) and 30 days to > or = 688 days was 0.39 (95% CI, 0.22 to 0.69). Consequently, early TIMI 3 flow was associated with approximately a 3 patient per 100 mortality reduction the first month with an additional 5 lives per 100 from 30 days to 2 years. For ejection fraction >40% compared with < or = 40%, the unadjusted hazard ratio was 0.25 (95% CI, 0.16 to 0.37) at 30 days and 0.22 (95% CI, 0.15 to 0.33) after 30 days through 2 years (lives saved, approximately 9 and 11 per 100, respectively).

CONCLUSIONS

Successful reperfusion and myocardial salvage produce significant mortality benefits that are amplified beyond the initial 30 days.

Thrombin generation, inhibition and clinical outcomes in patients with acute myocardial infarction treated with thrombolytic therapy and heparin: results from the GUSTO-I Trial. GUSTO-I Hemostasis Substudy Group. Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries

OBJECTIVES

We sought to assess the effects of antithrombotic therapy after thrombolysis for acute myocardial infarction on markers of thrombin generation and activity and to determine the relation of these markers with clinical outcomes.

BACKGROUND

Thrombin activation and generation often occur with thrombolysis for acute myocardial infarction. Antithrombotic regimens have been developed to reduce the resulting thrombotic complications.

METHODS

We sampled plasma markers of thrombin generation and activity after thrombolysis in 292 patients. We assessed the relations of these markers with clinical outcomes at 30 days.

RESULTS

Fibrinopeptide A (FPA), a marker of thrombin activity toward fibrinogen, was elevated at baseline (12.3 ng/ml) and increased to 18.4 ng/ml by 90 min after streptokinase and subcutaneous heparin treatment. With intravenous heparin, this increase was attenuated, but intravenous heparin did not prevent thrombin generation, as measured by prothrombin fragment 1.2 (F1.2). Heparin level, measured by anti-Xa activity, correlated with activated partial thromboplastin time (aPTT, r = 0.62 to 0.67). Thrombin activity, measured by FPA, was as closely related to aPTT as to the heparin level. Baseline levels of F1.2 were significantly related to the risk of death or reinfarction at 30 days (p = 0.008); values 12 h after enrollment also were related to 30-day mortality (p = 0.05).

CONCLUSIONS

Although intravenous heparin partly suppresses the increased thrombin activity associated with thrombolysis, it does not inhibit thrombin generation. The aPTT was as good a measure of suppression of thrombin activity as the heparin level itself. Hematologic markers of thrombin generation were found to be related to the subsequent risk of thrombotic events.

Non-Q-wave versus Q-wave myocardial infarction after thrombolytic therapy: angiographic and prognostic insights from the global utilization of streptokinase and tissue plasminogen activator for occluded coronary arteries-I angiographic substudy. GUSTO-I Angiographic Investigators

BACKGROUND

Although the stratification of patients with myocardial infarction into ECG subsets based on the presence or absence of new Q waves has important clinical and prognostic utility, systematic evaluation of the impact of thrombolytic therapy on the subsequent development and prognosis of non-Q-wave infarction has been limited to date.

METHODS AND RESULTS

We examined 12-lead ECG, coronary anatomy, left ventricular function, and mortality among 2046 patients with ST-segment elevation infarction from the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries angiographic subset to gain further insight into the pathophysiology and prognosis of Q- versus non-Q-wave infarction in the thrombolytic era. Non-Q-wave infarction developed in 409 patients (20%) after thrombolytic therapy. Compared with Q-wave patients, non-Q-wave patients were more likely to present with lesser ST-segment elevation in a nonanterior location. The infarct-related artery in non-Q-wave patients was more likely to be nonanterior (67% versus 58%, P=.012) and distally located (33% versus 39%, P=.021). Early (90-minute, 77% versus 65%, P=.001) and complete (54% versus 44%, P<.001) infarct-related artery patency was greater among the non-Q-wave group. Non-Q-wave patients had better global (ejection fraction, 66% versus 57%; P<.0001) and regional left ventricular function (10 versus 24 abnormal chords, P=.0001). In-hospital, 30-day, 1-year, and 2-year (6.3% versus 10.1%, P=.02) mortality rates were lower among non-Q-wave patients.

CONCLUSIONS

The excellent prognosis among the subgroup of patients who develop non-Q-wave infarction after thrombolysis is related to early, complete, and sustained infarct-related artery patency with resultant limitation of left ventricular infarction and dysfunction.

Benefit of early sustained reperfusion in patients with prior myocardial infarction (the GUSTO-I trial). Global Utilization of Streptokinase and TPA for occluded arteries

The primary objective of this study was to characterize a large cohort of patients receiving thrombolytic therapy for acute myocardial infarction with respect to the group with a prior event. Patients were randomly assigned to 1 of 4 thrombolytic strategies. Baseline characteristics, 30-day outcomes, and 1-year mortality were compared between patients with (n = 6,704) and without (n = 34,143) prior myocardial infarction. Patients with prior myocardial infarction presented to the hospital earlier than those having their first event, but institution of thrombolytic therapy was delayed. Mortality at 30 days (11.7% vs 5.9%, p = 0.001) and 1 year (17.3% vs 8.2%, p < 0.001) was greater among patients with prior infarction, and independent of other demographic variables. Accelerated alteplase was more effective than streptokinase or combination therapy (30-day mortality 10.4% vs 12.2%, p = 0.012; 1-year mortality 15.9% vs 17.8%, p = 0.041). Infarct vessel patency did not differ between those with and without prior myocardial infarction (67.3% vs 67% at 90 minutes, p = 0.92); however, recurrent ischemia was more common in patients with prior myocardial infarction. Patients with healed myocardial infarction should be educated to ensure early hospital admission if they develop symptoms suggestive of acute infarction, and upon hospital arrival should be promptly triaged to receive reperfusion therapy with accelerated alteplase.

End-systolic volume index at 90 to 180 minutes into reperfusion therapy for acute myocardial infarction is a strong predictor of early and late mortality. The Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO)-I Angiographic Investigators

BACKGROUND

Left ventricular remodeling is an important sequela of myocardial infarction (MI). Although remodeling occurs soon after MI, the effect of early left ventricular dilatation on outcome is not established and may be useful for early risk stratification. We assessed whether end-systolic volume index (ESVI) at 90 to 180 minutes into thrombolytic therapy for MI is associated with adverse outcomes.

METHODS AND RESULTS

In the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO)-I study, 41021 patients with evolving MI received one of four thrombolytic regimens. At 90 or 180 minutes into reperfusion therapy, 1300 patients underwent left ventriculography. ESVI was measured and correlated with adverse outcomes: 30-day and 1-year mortality and in-hospital congestive heart failure, shock, and reinfarction. Clinical variables were also tested in a stepwise logistic regression analysis to determine predictors of left ventricular dilatation. ESVI was directly related to all adverse outcomes with univariate analysis. ESVI of > or = 40 mL/m2 was independently associated with mortality (adjusted odds ratio [95% confidence interval]: 30-day, 3.4 [2.0 to 5.9]; 1-year, 4:1 [2.6 to 6.2], both P < .001). Male sex, prior angina or MI, weight of < 70 kg, heart rate of > or = 80 bpm, systolic blood pressure of < 110 mm.Hg, and anterior infarction were independent predictors of an ESVI of > or = 40 mL/m2.

CONCLUSIONS

Left ventricular ESVI early into reperfusion therapy for MI strongly predicts adverse outcomes, including early and late mortality. The study establishes the role of very early left ventricular dilatation on outcome in MI and may be useful in identifying high-risk patients who might benefit from aggressive treatment, including the early use of ACE inhibitors.

Incidence and impact on outcome of streptokinase allergy in the GUSTO-I trial. Global Utilization of Streptokinase and t-PA in Occluded Coronary Arteries

We evaluated allergic reactions in 20,201 patients randomized to the streptokinase arms of The Global Utilization of Streptokinase and t-PA (Tissue Plasminogen Activator) in Occluded Coronary Arteries (GUSTO-I) trial, and tested the hypothesis that patients with streptokinase allergy would exhibit higher mortality. After adjusting for baseline variables and time of death, we found comparable coronary patency, left ventricular function, mortality, and bleeding complications between patients with versus those without streptokinase allergy.

Prevalence of spinal disc disease among interventional cardiologists

A suspected, but undocumented, excess of axial skeletal disease among interventional cardiologists (possibly a consequence of lead apron use) was investigated by comparing questionnaire responses from cardiologists, orthopedic surgeons, and rheumatologists (n = 714). Cardiologists reported more neck and back pain, more subsequent time lost from work, and a higher incidence of cervical disc herniations, as well as multiple level disc disease (all p <0.01): "interventionalist's disc disease" is a confirmed entity.