Hospital delays and problems with thrombolytic administration in patients receiving thrombolytic therapy: a multicenter prospective assessment. Virginia Thrombolytic Study Group.

STUDY OBJECTIVES: To assess the timing of key decisions and clinical events in the treatment of acute myocardial infarction with thrombolytic therapy. DESIGN: Prospective study of emergency department patients. SETTING: EDs in 11 urban and two rural hospitals. TYPES OF PARTICIPANTS: Patients with presumed acute myocardial infarction for whom a decision was made in the ED to administer thrombolytic therapy. MEASUREMENTS AND MAIN RESULTS: Statistical analyses included determination of frequency of response, cross tabulation analysis, and Wilcoxon rank sum tests. In 210 thrombolytic-treated patients (mean age, 57 +/- 14.1 years), a median time of 155 minutes elapsed between pain onset and therapy; 67% of the delay was pre-ED arrival. The median time between ED arrival and the initial ECG was six minutes. The median time required for physicians to make a treatment decision was 20 minutes, followed by another median time of 20 minutes for staff to begin drug infusion. The median total hospital (door-to-needle) time was 50 minutes. Significantly shorter delays occurred in urban, teaching, and high-volume hospitals; when thrombolytics were stocked and/or started in the ED; and when emergency physicians treated without involving private attending physicians. Although 95% of patients received tissue plasminogen activator, six patients treated with anisoylated plasminogen-streptokinase activator complex experienced a significantly faster door-to-needle time (P less than .05). CONCLUSION: Thrombolytics should be stocked and started in the ED. Emergency physicians should generally make the decision to administer thrombolytic therapy with reference to accepted protocols without awaiting an ED consultation from either private attendings or cardiologists.     

Age-Specific Differences in the Use of Thrombolytic Therapy and Hospital Outcomes in Patients with Acute Myocardial Infarction: A Community-Wide Perspective

Background: Relatively limited information is available about recent, and trends over time, use of thrombolytic therapy in patients of different ages hospitalized with acute myocardial infarction and the association between use of thrombolytic therapy and hospital outcomes. Methods: We conducted an observational study of 5601 residents of the Worcester, Massachusetts, metropolitan area (1990 census = 437,000) with confirmed acute myocardial infarction in all local hospitals during 6 one-year periods between 1990 and 1999. Results: Despite relatively stable use of thrombolytic therapy between 1990 and 1995, decreases in the use of thrombolytic therapy in all patients with acute myocardial infarction were observed in 1997 and 1999. There was a 1.6 fold decrease in the use of thrombolytic therapy between 1990 and 1999 in patients <65 years. Patients 65–74 years (33.7% 1990; 11.7% 1999) and those 75 years and older (10.8% 1990; 6.7% 1999) experienced marked decreases in the receipt of thrombolytic therapy over time. Use of thrombolytic therapy was associated with reduced hospital mortality in each of the four age-specific groups under study (<55, 55–64, 65–74, 75) through the degree of benefit on hospital death rates associated with the use of thrombolytic therapy was attenuated after adjustment for additional confounders. Conclusions: Our findings indicate recent declines in the use of thrombolytic therapy in middle-aged and elderly patients with acute myocardial infarction. The impact of thrombolytic therapy on hospital outcomes was observed in each of our age strata under study though the magnitude of absolute and relative benefit varied according to age. Miniabstract. Declines in the use of thrombolytic therapy were observed between 1900 and 1999 in a population-based sample of patients with acute myocardial infarction. Use of thrombolytic therapy was associated with improved hospital survival to varying degrees in each of the age groups under study.     

Delayed thrombolytic treatment of older patients with acute myocardial infarction.

OBJECTIVE: To determine demographic and clinical factors associated with delayed thrombolysis in patients with acute myocardial infarction. DESIGN: A retrospective cohort. SETTING: 37 Minnesota hospitals during the time periods October 1992-July 1993 and July 1995-April 1996. PATIENTS: We reviewed the medical records of 776 older patients aged 65 or older hospitalized with an admission diagnosis of acute myocardial infarction, suspected acute myocardial infarction, or rule-out acute myocardial infarction, who were treated with a thrombolytic agent. MEASUREMENT: We used multivariate logistic regression models to examine the association between selected study characteristics and time between hospital presentation and administration of thrombolytic treatment. Early thrombolysis was defined as less than 60 minutes after hospital presentation and late thrombolysis as 60+ minutes. RESULTS: Of 776 study patients, 57.5% (n = 446) received early thrombolysis. Of the remaining 330 patients receiving late treatment, 12.1% (n = 94) were thrombolyzed more than 2 hours after hospital presentation. After controlling for other factors, the odds of delayed thrombolysis among patients aged 75 or older were 1.48 compared with younger individuals (95% CI, 1.17-1.88). The odds of delayed thrombolysis among patients with severe comorbidity were 1.46 (95% CI, 1.10-1.94) compared with individuals without severe comorbidity. Predictors of early thrombolytic treatment included hospital arrival via emergency transport (ORdelay = 0.46; 95% CI, 0.34-0.63) and chest discomfort at admission (ORdelay = 0.40; 95% CI, 0.18-0.86). CONCLUSIONS: The present study indicates that patients of advanced age and with severe comorbidity are more likely to experience delayed thrombolytic treatment after hospital presentation. These are the patients who suffer the highest morbidity from acute myocardial infarction and for whom expeditious treatment may enhance therapeutic benefit.     

Improved efficiency in acute myocardial infarction care through commitment to emergency department-initiated primary PCI

STUDY OBJECTIVE: Demonstrate improved efficiency of initial and subsequent in-hospital care following emergency department (ED) physician-initiated primary angioplasty (1 PCI). METHODS: An observational study was undertaken in ST-elevation myocardial infarction patients presenting to a community hospital emergency department. Outcomes of patients who received ED physician-directed 1 PCI were compared with patients previously treated by a mix of ED physician and cardiologist co-determined thrombolysis or 1 PCI. A process improvement initiative supported the change to ED-directed 1 PCI. RESULTS: The study included 287 eligible acute reperfusion patients. Median door-to-balloon time (MDBT) improved from 88 minutes (95% CI, 80 96) to 61 minutes (95% CI, 57 70; p < 0.0001). Necessary subsequent in-hospital interventions (NSI) occurred in 70 of 107 (65.4%; 95% CI, 55.6 74.4%) thrombolytic patients, versus 3 of 99 (3.0%; 95% CI, 0.6 8.6%) 1 PCI patients at baseline, and 1 of 81 (1.2%; 95% CI, 0.0 6.7%) 1 PCI patients after process change. Median length of stay (LOS) decreased from 4 days for thrombolytic patients and 3 days for 1 PCI patients at baseline, to 2 days for 1 PCI after adopting the improved process (p < 0.0001). Effectiveness outcomes demonstrating improvement included discharge on beta-blocker (p = 0.0039), angiotensin-converting-enzyme inhibitor (p < 0.0001) and anti-lipid therapy (p = 0.0039), with favorable trends in survival to discharge, and 30-day major adverse cardiac events (MACE). CONCLUSIONS: Conversion to ED physician-initiated 1 PCI for ST-elevation myocardial infarction significantly improved efficiency of care as measured by MDBT, NSI and LOS. Effectiveness measures, including survival to discharge, discharge medications and 30-day MACE, demonstrated improvement or favorable trends.     

Emergency aeromedical transport of patients with acute myocardial infarction

Traditional medical treatment of acute myocardial infarction (AMI) calls for immediate admission and observation in a special care unit and prohibits early interhospital transfer of patients. If persons with AMI are to benefit from emergency thrombolytic therapy, angioplasty, and other interventions, they may require emergency transfer within hours to one of the 10% of hospitals that provide these services. We report our experience with the emergency aeromedical treatment and transfer for acute intervention of 104 consecutive patients with suspected AMI. Between May 1983 and December 1984, 104 patients with suspected acute myocardial infarction were transported by an aeromedical team, including a physician and nurse, for emergency cardiac evaluation. AMI was confirmed in 94 (90%), and emergency intervention was carried out in 75 of 104 (72%). Ninety patients (87%) survived to be discharged from the hospital. There were no deaths during transport. Complications requiring treatment occurred in 13 (12%) of the patients during transport; physician skill or judgment was exercised in 27 of 104 transports (26%) and did not correlate with the Killip classification of physical findings. We conclude that emergency transfer of patients with AMI, traditionally considered hazardous, can be carried out safely using an aeromedical team. Physicians appear to play an important role in safe transport.     

Use of thrombolytic treatment in patients with acute myocardial infarction in Spain. Observations from the PRIAMHO study

INTRODUCTION AND OBJECTIVES: Scarce information is actually available in our country regarding the use of thrombolytic treatment in patients with acute myocardial infarction and how consistently the recommendations of the clinical guidelines are being implemented. METHODS: Cohort study with one year follow-up of patients with acute myocardial infarction admitted in 24 Spanish hospitals in 1995. Differences in clinical characteristics and prognosis from patients treated with or without thrombolysis were compared. RESULTS: 2,191 of the 5,242 patients (42%) admitted with an acute myocardial infarction received thrombolytic therapy (range: 23%-63%). Reasons for exclusion in the rest were the absence of ST segment elevation (35%), contraindications (16%), prehospital delay >12 h (35%), and other causes (15%). Thrombolysis treated patients were at lower risk in general because they had shorter prehospital delays and were younger, more likely to be male, less frequently diabetic, with less prior history of angina or infarction. The average delay in administering therapy was of 3 hours while the average in-hospital delay was 50 minutes and depended only on the hospital where patients where admitted, as it was shorter in small centers. t-PA was administered in 49% of patients, streptoquinase in 46% and other drugs in 5%. Although t-PA was given more often to younger patients, smokers, anterior and Q-wave infarctions, and to patients with shorter prehospital delays, the determinant factor was the admission hospital with a frequency ranging from 9% to 96%. Patients not treated with thrombolytics had more complications during the acute phase, and required more invasive procedures. They also had a higher mortality at 28 days (17% vs. 10%, p < 0.0001) and at one-year follow-up (27% vs. 15%, p < 0.0001). Furthermore, a correlation was observed between mortality and delay of treatment application. In multivariate analysis, thrombolytic treatment was an independent predictor of survival at one year, with an odds ratio for mortality of 0.8 (95% CI: 0.66-0.96). CONCLUSIONS: Thrombolytic therapy in Spain does not yet conform to the recommendations of the actual guidelines for the treatment of patients with acute myocardial infarction because it is underused, especially in high-risk patients, the prehospital and in-hospital delays are too long, and a huge variability exists between hospitals in the frequency and delays of administration and selection of the drug that are not sufficiently explained by the characteristics of the patients. In spite of this, mortality of treated patients was 20% lower in comparison to the non-treated patients, after adjusting for the other clinical factors with demonstrated prognostic value.     

Multicentre randomized trial comparing transport to primary angioplasty vs immediate thrombolysis vs combined strategy for patients with acute myocardial infarction presenting to a community hospital without a catheterization laboratory. The PRAGUE study.

BACKGROUND: Primary coronary angioplasty is an effective reperfusion strategy in acute myocardial infarction. However, its availability is limited, and transporting patients to an angioplasty centre in the acute phase of myocardial infarction has not yet been proved safe. METHODS: The PRAGUE study (PRimary Angioplasty in patients transferred from General community hospitals to specialized PTCA Units with or without Emergency thrombolysis) compared three reperfusion strategies in patients with acute myocardial infarction, presenting within 6 h of symptom onset at community hospitals without a catheterization laboratory: group A - thrombolytic therapy in community hospitals (n=99), group B - thrombolytic therapy during transportation to angioplasty (n=100), group C - immediate transportation for primary angioplasty without pre-treatment with thrombolysis (n=101). RESULTS: No complications occurred during transportation in group C. Two ventricular fibrillations occurred during transportation in group B. Median admission-reperfusion time in transported patients (group B 106 min, group C 96 min) compared favourably with the anticipated >90 min in group A. The combined primary end-point (death/reinfarction/stroke at 30 days) was less frequent in group C (8%) compared to groups B (15%) and A (23%, P<0. 02). The incidence of reinfarction was markedly reduced by transport to primary angioplasty (1% in group C vs 7% in group B vs 10% in group A, P<0.03). CONCLUSIONS: Transferring patients from community hospitals to a tertiary angioplasty centre in the acute phase of myocardial infarction is feasible and safe. This strategy is associated with a significant reduction in the incidence of reinfarction and the combined clinical end-point of death/reinfarction/stroke at 30 days when compared to standard thrombolytic therapy at the community hospital.     

Thrombolysis in the elderly with acute myocardial infarction. The PRIAMHO study

INTRODUCTION: In the elderly with acute myocardial infarction the risks and benefits of thrombolytic therapy are not well defined due mainly to the lack of randomized trials. In the present study we examined the clinical profile of the aged treated with thrombolytic agents and the effects of that therapy on 28 day and 1 year mortality. PATIENTS AND METHODS: We studied 733 patients aged > 75 years (mean: 79.9) admitted to the Coronary Care Unit (CCU) of 24 Spanish hospitals with a confirmed diagnosis of Q-Wave myocardial infarction (MI). On admission, 293 patients were treated with thrombolytics and 440 patients received standard therapy. The difference between the two groups in the clinical profile of MI, treatments administered in CCU, evolutive course and 28 day and 1 year mortality were assessed.RESULTS: The independent predictors related to the use of thrombolytic therapy were age (OR: 0.93; 95% CI: 0.89-0.97), history of arterial hypertension (OR: 0.85; 95% CI: 0.71-1.01), delay time to admission (OR: 0.998; 95% CI: 0.997-0.999), anterior location of infarct (OR: 1.21; 95% CI: 1.01-1.24) and Killip Class III-IV (OR: 0.79; 95% CI: 0.64-0.97). During the evolution thrombolysis therapy was associated with lower rates of Killip III-IV (p < 0.00001), complete AV block (p = 0.037), intraventricular conduction defects (p = 0.046) and a higher incidence of stroke (p < 0.01). The 28-day mortality was also significantly lower in the group receiving thrombolytics (27 vs 31. 3%; p = 0.035). However, this difference disappeared when the analysis was adjusted with other variables such as age, administration of aspirin and Killip Class III-IV (OR: 1.29; 95% IC: 0.87-1.92). CONCLUSIONS: The results of this trial suggest that in the elderly with acute myocardial infarction thrombolysis is associated with a less complicated evolutive course and a lower 28-day mortality. However, these findings could be mediated by other covariables such as age, more frequent use of aspirin and a higher number of patients with Killip Class III-IV excluded from the thrombolytic therapy.     

Akuter Myokardinfarkt in Deutschland im Zeitraum zwischen 1996 und 1998: Therapie und hospitaler Verlauf

The "Myocardial Infarction Registry" in Germany (MIR) is a multicenter and prospective registry of consecutively included, unselected patients with acute myocardial infarction. The purpose of MIR is to document the actual praxis of decision making and prescribing of an optimized infarction therapy in AMI patients. Optimized infarction therapy is defined as the combination of reperfusion therapy and ASS, betablocker, and ACE inhibitor.14,598 patients with acute myocardial infarction were included between 12/96 and 5/98 in 217 hospitals throughout Germany. 68% of the patients were male; mean age was 67 years. The prehospital delay time was 195 minutes in median, the first ECG was diagnostic in 66% of the patients. A reperfusion therapy was applied in 46.1% of the patients (thrombolysis 36.2%, primary PTCA 9.9%). During the acute phase, the following adjunctive therapy was used: ASS in 90.3%, betablockers in 53.8%, and ACE inhibitors in 52.5%. Intrahospital mortality was 15.4%. Compared to hospitals without cardiologists, the hospitals with cardiologist had a lower intrahospital mortality (13.8% versus 16.1%; p < 0.001). Reasons are the more frequent use of a reperfusion therapy by cardiologists (54.3% versus 42.3%; p < 0. 001) and the availability of a catheter laboratory with PTCA facilities.A lower intrahospital mortality was associated with each therapy of the optimized infarction therapy: reperfusion therapy (odds ratio 0.7; 95% CI: 0.5-0.8), ASS (odds ratio 0.6; 95% CI: 0. 5-0.8), betablocker (odds ratio 0.6; 95% CI: 0.5-0.7) and ACE inhibitor (odds ratio: 0.5; 95% CI: 0.4-0.7). However, patients with poor initial prognosis - such as cardiogenic shock, hypotension and/or bradycardia - could not benefit from the orally adjunctive therapy. This fact may have led to an overestimation of the influence on intrahospital mortality.In representative communal German hospitals, a reperfusion therapy in combination with an optimized adjunctive therapy in patients with acute myocardial infarction is associated with a reduction in intrahospital mortality. Compared to previous registries, the application of betablockers and ACE inhibitors was clearly increased. Reasons could be the participation in a quality registry, the obligation to document why a therapy has not been given and repeated and intensified education of the treating physicians.Thus, the mainly communal hospitals in Germany are increasingly following recommendations about the early treatment of acute myocardial infarction. Myocardial infarction registries such as MIR reflect daily prescribing habits in hospitals and describe the implementation of the results of randomized trials into daily routine.     

A randomized trial of the effects of early cardiac serum marker availability on reperfusion therapy in patients with acute myocardial infarction: the serial markers, acute myocardial infarction and rapid treatment trial (SMARTT)

OBJECTIVES: The purpose of this study was to assess whether the immediate availability of serum markers would increase the appropriate use of thrombolytic therapy. BACKGROUND: Serum markers such as myoglobin and creatine kinase, MB fraction (CK-MB) are effective in detecting acute myocardial infarction (AMI) in the emergency setting. Appropriate candidates for thrombolytic therapy are not always identified in the emergency department (ED), as 20% to 30% of eligible patients go untreated, representing 10% to 15% of all patients with AMI. Patients presenting with chest pain consistent with acute coronary syndrome were evaluated in the EDs of 12 hospitals throughout North America. METHODS: In this randomized, controlled clinical trial, physicians received either the immediate myoglobin/CK-MB results at 0 and 1 h after enrollment (stat) or conventional reporting of myoglobin/CK-MB 3 h or more after hospital admission (control). The primary end point was the comparison of the proportion of patients within the stat group versus control group who received appropriate thrombolytic therapy. Secondary end points included the emergent use of any reperfusion treatment in both groups, initial hospital disposition of patients (coronary care unit, monitor or nonmonitor beds) and the proportion of patients appropriately discharged from the ED. RESULTS: Of 6,352 patients enrolled, 814 (12.8%) were diagnosed as having AMI. For patients having AMI, there were no statistically significant differences in the proportion of patients treated with thrombolytic therapy between the stat and control groups (15.1% vs. 17.1%, p = 0.45). When only patients with ST segment elevation on their initial electrocardiogram were compared, there were still no significant differences between the groups. Also, there was no difference in the hospital placement of patients in critical care and non- critical care beds. The availability of early markers was associated with more hospital admissions as compared to the control group, as the number of patients discharged from the ED was decreased in the stat versus control groups (28.4% vs. 31.5%, p = 0.023). CONCLUSIONS: The availability of 0- and 1-h myoglobin and CK-MB results after ED evaluation had no effect on the use of thrombolytic therapy for patients presenting with AMI, and it slightly increased the number of patients admitted to the hospital who had no evidence of acute myocardial necrosis.     

Impact of thrombolytic therapy on short and long-term survival of a cohort of patients with acute myocardial infarction consecutively admitted to all the hospitals of a health care area. GESIR-5 study

AIM: This study aims to assess the application of thrombolysis in patients with acute myocardial infarction admitted to all the hospitals of a health care area in Catalonia (Spain), and to estimate the effect of thrombolysis on short and long-term survival. METHODS: From May 1992 to May 1993, all the patients with myocardial infarction admitted to the hospitals of the Costa de Ponent area in the first 72 hours after the initial symptoms were consecutively included in this prospective study. Information on pre-hospital phase, emergency room management and hospitalization was collected. All the patients discharged alive from hospital were followed up by telephone one and four years after hospital admission. RESULTS: 521 patients aged 74 years or less were included. Thrombolytic therapy was applied in 35.3%. There were no statistically significant differences in the proportion of thrombolysis between hospitals with or without intensive care or coronary units. Ten patients died in the emergency room; in the remaining cases, the 28-day case fatality was 10.0%. The effect of thrombolytic treatment on 28-day case fatality was estimated in a logistic regression model, after controlling for age, gender, Killip, ventricular arrhythmia and location of infarction (OR: 0.36; CI 95%: 0.15-0.88). In 28-day survivors, the 4-year cumulated probability of survival was 88.4%, being significantly higher in the group who had received thrombolytic therapy. CONCLUSIONS: In the population studied, 28-day case mortality of acute myocardial infarction is similar to that reported in other Mediterranean regions. The benefits of thrombolysis in the acute phase are found to persist after 4 years.     

Feasibility of prehospital r-TPA therapy in chest pain patients.

STUDY OBJECTIVE: The purpose of this study was to determine the number of eligible prehospital thrombolytic candidates and to estimate the potential time saved if field thrombolysis had been initiated in a series of prehospital chest pain patients. DESIGN AND SETTING: Prehospital 12-lead ECGs were obtained by paramedics during initial evaluation of chest pain patients and stored in the computerized ECG. Prehospital 12-lead ECGs, prehospital charts, and hospital charts then were reviewed retrospectively for final hospital diagnosis, prehospital and emergency department times, and historical exclusion criteria for prehospital treatment with recombinant tissue-type plasminogen activator (r-TPA). TYPE OF PARTICIPANTS: One hundred fifty-seven stable adult prehospital patients with a chief complaint of nontraumatic chest pain were enrolled. Six patients were excluded. Two had unretrievable 12-lead ECGs, and four refused paramedic transport and thus provided no further data. There were complete data on 151 patients making up the final study population. INTERVENTIONS: Prehospital care was unaltered except for acquisition of 12-lead ECGs. No prehospital thrombolytic therapy was administered during this study. MEASUREMENTS AND MAIN RESULTS: The incidence of r-TPA exclusion criteria was as follows: 45 patients (29%) were 75 years of age or older, 57 (38%) had chest pain for more than six hours, 24 (16%) had hypertension with blood pressure of more than 180/110 mm Hg, and six (4%) had a history of a cerebrovascular accident. The time from paramedic scene arrival to prehospital ECG (8.4 +/- 5.1 minutes) was significantly shorter than the time from ED arrival to ED ECG (24.2 +/- 21.6 minutes, P less than .001). Prehospital ECGs increased paramedic scene time over a retrospective control by 5.2 minutes. Mean time from prehospital ECG to ED ECG (potential time saved) was 50.2 + 22.4 minutes in all patients and 43.4 +/- 7.7 minutes in patients with a final diagnosis of acute myocardial infarction (P = NS). Thirteen of 151 patients (8.6%) had prehospital ECGs diagnostic for acute myocardial infarction; eight of these (5.3% overall) met criteria for prehospital r-TPA therapy. CONCLUSION: Prehospital 12-lead ECGs provide an ECG diagnosis 40 to 50 minutes earlier than ED ECGs. However, with current exclusion criteria, the number of prehospital r-TPA candidates is limited.     

Pharmacological profile of survivors of acute myocardial infarction at Turkish academic hospitals

AIM: The purpose of this study was to document treatment profiles in 850 patients surviving acute myocardial infarction at 17 academic hospitals in Turkey. METHODS AND RESULTS: Pharmacological management data of acute myocardial infarction survivors were collected and divided into three categories: drugs which patients received before hospitalization, during the hospitalization, and at hospital discharge. Data regarding medical history, complications during hospitalization, MI extent (Q wave or non-Q wave), infarct location and diagnostic and revascularization procedures were also recorded. This study is based on the 850 patients who met the diagnostic criteria for initial acute MI in the period examined. Among 850 patients with myocardial infarction enrolled 408 (48%) received thrombolytic therapy. The median time interval from symptom onset to initiation of thrombolytic therapy was 196 min. The most commonly used thrombolytic agent was streptokinase (93%). Thrombolytic recipients were younger, and presented sooner after onset of symptoms. Among patients receiving thrombolytic therapy, concomitant pharmacotherapy included aspirin (95%), intravenous heparin (93%), intravenous nitroglycerin (91%), oral beta-blockers (44%), calcium channel antagonists (13%), and angiotensin converting enzyme inhibitors (41%). The lipid lowering therapy was only used in 4% of all patients, and was given to 18% of patients with hyperlipidemia. CONCLUSION: Current usage rates of thrombolytic therapy in Turkey are lower than expected, but when compared with previous reports it increased. Although adjunctive treatment with intravenous heparin and intravenous nitroglycerin is usually used, beta-blockers appear to be underused and calcium channel blockers appear to be overused. The lipid reducing therapies were infrequently prescribed.     

Recent aspirin use is associated with smaller myocardial infarct size and lower likelihood of Q-wave infarction.

BACKGROUND: Controversy exists about the effect of recent aspirin use on infarct size and the likelihood of Q-wave infarction in patients who sustain myocardial infarction. METHODS: We performed face-to-face interviews and chart reviews on 3665 patients with acute myocardial infarction for the Determinants of Myocardial Infarction Onset Study. For the 2206 patients who did not receive thrombolytic therapy, we assessed aspirin use, peak creatine kinase levels (in 1043 patients), and electrocardiographic interpretations (in 1447 patients). RESULTS: Of the initial 1043 patients, 317 (30. 3%) subjects reported aspirin use in the 4 days before their infarction. The mean +/- SD peak creatine kinase level for aspirin users was 701 +/- 570 IU/mL versus 851 +/- 727 IU/mL for nonusers, an 18% difference (95% confidence interval [CI], 8% to 26%; P <.001). After adjustment for confounding factors, the difference was 12% (95% CI, 2% to 21%; P =.03). Similarly, 38.9% of the aspirin users and 48.7% of the nonusers sustained a Q-wave infarction, an odds ratio of 0.67 (95% CI, 0.54 to 0.83, P <.001). The adjusted odds ratio was 0.77 (95% CI, 0.61 to 0.97, P =.03). CONCLUSIONS: Recent aspirin use was associated with smaller infarct size and fewer Q-wave infarctions among this population of early survivors of acute myocardial infarction who did not receive thrombolytic therapy.     

Can a nurse trained in coronary care expedite emergency department management of patients with acute coronary syndromes?

OBJECTIVE: The goal of this study was to determine the effect of a coronary care-trained nurse (CCTN) on transfer times of patients presenting with acute coronary syndromes (ACS) from the emergency department (ED) to the coronary care unit (CCU) for definitive cardiac treatment (DCT). DESIGN: This was a prospective randomized controlled study. SETTING: The study took place in the ED of a metropolitan public teaching hospital in South Australia. PATIENTS: The study sample was comprised of 893 patients who presented to the ED with a complaint of chest pain. INTERVENTION: An experienced senior CCTN was randomly assigned to work in an ED for 16 randomly selected hours per week; comparable hours over the same period without a CCTN in attendance were used as control data. The major endpoint was time to CCU transfer where DCT was completed for patients with ACS. RESULTS: Out of 893 patients assessed as having possible ACS, 91 (10%) were admitted to the CCU, 47 with a diagnosis of unstable angina pectoris (UAP) and 44 with a diagnosis of acute myocardial infarction. Nineteen patients required thrombolysis and/or percutaneous coronary angioplasty. Mean times (in minutes) to transfer for DCT (95% CI) were 102 (70-134) and 117 (95-139) in the presence and absence of a CCTN, respectively, for all ACS, and 33 (10-55) and 54 (25-82), respectively, for acute myocardial infarction requiring thrombolysis and/or percutaneous coronary angioplasty. CONCLUSIONS: These pilot data show a nonsignificant trend suggesting that DCT is expedited by assignment of senior CCTNs to EDs and provides direction for further study.     

Additional ST segment elevation during the first hour of thrombolytic therapy: an electrocardiographic sign predicting a favorable clinical outcome.

OBJECTIVES. The aim of this study was to investigate the significance of further ST elevation that occurs during the 1st h of thrombolytic therapy before the expected resolution. BACKGROUND. Early resolution of ST segment elevation is commonly accepted as a marker of clinical reperfusion during thrombolytic therapy for acute myocardial infarction. Using frequent electrocardiographic recordings, we observed in some patients further ST elevation that occurred during hour 1 of thrombolysis before the expected resolution. METHODS. To investigate the significance of this pattern, we classified 177 consecutive patients with a first acute myocardial infarction into two groups: Group A, 98 patients with ST elevation > or = 1 mm above the initial ST elevation during the 1st h of thrombolytic therapy, and Group B, 79 patients without this finding. RESULTS. Although the presence or absence of additional ST elevation was not associated with a clinical or prognostic difference in patients with a first inferior or posterior acute myocardial infarction, its presence indicated a more favorable clinical outcome and prognosis in patients with anterior infarction. Among the patients with anterior infarction the 65 patients in Group A had a higher ejection fraction (44 +/- 9% vs. 35 +/- 11%, p < 0.01), less heart failure (15% vs. 35%, p = 0.02) and a lower in-hospital mortality rate (0% vs. 8%, p = 0.04) than did the 37 patients from Group B. CONCLUSIONS. Additional ST elevation early during thrombolytic therapy in patients with anterior infarction suggests a favorable clinical outcome and thus may be indicative of successful reperfusion.     

Gender differences in acute myocardial infarction in the era of reperfusion (the MITRA registry)

There is conflicting information about gender differences in presentation, treatment, and outcome after acute ST elevation myocardial infarction (STEMI) in the era of thrombolytic therapy and primary percutaneous coronary intervention. From June 1994 to January 1997, we enrolled 6,067 consecutive patients with STEMI admitted to 54 hospitals in southwest Germany in the Maximal Individual TheRapy of Acute myocardial infarction (MITRA), a community-based registry. Women were 9 years older than men, more often had hypertension, diabetes mellitus, and congestive heart failure, and had a history of previous myocardial infarction less often. Women had a longer prehospital delay (45 minutes), had anterior wall infarction more often (odds ratio [OR] 1.21; 95% confidence interval [CI] 1.08 to 1.36), and received reperfusion therapy less often (OR 0.83; 95% CI 0.74 to 0.94). The percentage of patients who were eligible for thrombolysis and received no reperfusion was higher in women (OR 1.7; 95% CI 1.56 to 1.89). Women had recurrent angina (OR 1.45; 95% CI 1.23 to 1.71) and congestive heart failure (OR 1.26; 95% CI 1.01 to 1.56) more often. There was a trend toward a higher hospital mortality in women (age-adjusted OR 1.16, 95% CI 0.99 to 1.35; multivariate OR 1.21, 95% CI 0.96 to 1.51), but there was no gender difference in long-term mortality after multivariate analysis (age-adjusted OR 0.95, 95% CI 0.78 to 1.15; multivariate OR 0.93, 95% CI 0.72 to 1.19). Thus, women with STEMI receive reperfusion therapy less often than men. They experience recurrent angina and congestive heart failure more often during their hospital stay. The age-adjusted long-term mortality is not different between men and women, but there is a trend for a higher short-term mortality in women.     

Reperfusion arrhythmia: myth or reality?

Early reports of "reperfusion arrhythmia" after experimental temporary coronary occlusion raised concern that these arrhythmias, particularly ventricular fibrillation and ventricular tachycardia, might occur in association with reperfusion of an occluded coronary vessel during thrombolysis. Such an occurrence could increase the risk of transfer of such patients. To provide a more definitive answer to this question, we reviewed hospital and transfer records for all patients with acute myocardial infarction transferred by our critical care transfer service between January 1, 1985, and November 30, 1987, noting the occurrence of five types of arrhythmia: ventricular fibrillation, ventricular tachycardia, premature ventricular contractions, bradycardia, and atrioventricular block, both before and during transfer. Five hundred patients with acute myocardial infarction less than 48 hours old were transferred during this period. Two hundred twenty-five patients received thrombolytic therapy; 270 did not (five unknown). The type of acute myocardial infarction was known for 471 patients: 192 were anterior, 203 were inferior, and 76 were lateral. There were no deaths during transfer. Overall survival through hospitalization was 91%. The incidence of arrhythmia was 36% before transport and 12% during transport. There was no difference in arrhythmias overall, or with respect to any of the five arrhythmias specified, between patients who received thrombolytic therapy before and during transport and those who did not. Reperfusion arrhythmia does not appear to be a clinically significant entity during the transport of patients who are receiving IV thrombolytic therapy.     

Streptokinase and tissue plasminogen activator in acute myocardial infarction

The use of thrombolytic agents for the treatment of myocardial infarction is increasing. Many community hospitals are infusing SK intravenously and those with cardiac catheterization laboratories often use intracoronary SK and angioplasty. Tissue plasminogen activator is undergoing extensive clinical trials, and reports of this research should add to our knowledge of this new therapy. Recently, benefits from thrombolytic therapy such as increased ejection fraction, improved regional wall motion, and short-term decreases in mortality have been documented. Both the GISSI trial that recruited 11,712 patients in Italy and the Netherlands trial documented significant short-term decreases in mortality after therapy with SK compared with control groups. As this information reaches the medical community, we may see an increase in the use of thrombolytic therapy during acute myocardial infarction. Additionally, community education service organizations should reemphasize the importance of seeking help early after the signs and symptoms of acute myocardial infarction appear to promote early treatment and potential salvage of greater amounts of myocardium. The long-term prognosis of patients who have been successfully reperfused and the best management after thrombolytic therapy is not yet known. Future problems and benefits from this therapy are still to be determined.     

Safety of helicopter transport and out-of-hospital intravenous fibrinolytic therapy in patients with evolving myocardial infarction

Of 150 consecutive patients with acute myocardial infarction transported by helicopter for acute intervention, 55 had intravenous thrombolytic therapy (tissue plasminogen activator in 12, streptokinase in 43) initiated prior to transfer. Patients were transported 55 +/- 10 ground miles in 17 +/- 6 minutes and no patient died or experienced bleeding or hemodynamic instability during transfer. Patients receiving thrombolytic therapy had a higher incidence of arrhythmias during transit compared to the untreated group, ventricular tachycardia in six and third-degree atrioventricular block in one compared to ventricular tachycardia in one patient, respectively (p = 0.005). However, these arrhythmias were transient and did not require cardioversion, temporary pacing, or further antiarrhythmic medical treatment. Chest pain was relieved or decreased more frequently in the patients receiving thrombolytic therapy vs. those untreated; 21 of 55 vs. 21 of 95 respectively (p = 0.04). Immediate coronary angiography confirmed a higher incidence and more complete infarct vessel patency (34/55 vs. 30/95) in the patients receiving tissue plasminogen activator or streptokinase (p less than 0.001). Thus, helicopter transfer of patients with evolving myocardial infarction is safe, and early initiation of thrombolytic therapy is associated with increased infarct vessel patency and benign reperfusion arrhythmias.