Consultation before thrombolytic therapy in acute myocardial infarction. Second National Registry of Myocardial Infarction (NRMI 2) Investigators.

Among 57,398 thrombolytic recipients in the National Registry of Myocardial Infarction 2, consultation with another physician was sought in 64% before initiating lytic therapy, although presenting features were typical, rather than atypical, in most patients. Consultation significantly delayed the administration of lytic therapy and was associated with increased hospital mortality.

Use of reperfusion therapy for acute myocardial infarction in the United States: data from the National Registry of Myocardial Infarction 2.

BACKGROUND: There is clear evidence that reperfusion therapy improves survival in selected patients with an acute myocardial infarction. However, several studies have suggested that many patients with an acute myocardial infarction do not receive this therapy. Whether this underutilization occurs in patients appropriate for such therapy remains unclear. METHODS AND RESULTS: We examined the use of reperfusion therapy in patients with an acute myocardial infarction hospitalized at 1470 hospitals participating in the National Registry of Myocardial Infarction 2. We identified 84 663 patients who were eligible for reperfusion therapy as defined by diagnostic changes on the initial 12-lead ECG, presentation to the hospital within 6 hours from symptom onset, and no contraindications to thrombolytic therapy. Twenty-four percent of these eligible patients did not receive any form of reperfusion therapy (7.5% of all patients). When multivariate analyses were used, left bundle-branch block (odds ratio [OR]=0.22; 95% CI=0.20 to 0.24), lack of chest pain at presentation (OR=0.22; 95% CI=0.21 to 0.24), age >75 years (OR=0.40, 95% CI=0.36 to 0.43), female sex (OR=0.88, 95% CI=0.83 to 0.92), and various preexisting cardiovascular conditions were independent predictors that the patient would not receive reperfusion therapy. CONCLUSIONS: Reperfusion therapy may be underutilized in the United States. Increased use of reperfusion therapy could potentially reduce the unnecessarily high mortality rates observed in women, the elderly, and other patient groups with the highest risk of death from an acute myocardial infarction.

The prehospital electrocardiogram in acute myocardial infarction: is its full potential being realized? National Registry of Myocardial Infarction 2 Investigators.

OBJECTIVES: This study sought to examine the management and subsequent outcomes of patients with a prehospital electrocardiogram (ECG) in a large, voluntary registry of myocardial infarction. BACKGROUND: The prehospital ECG has been proposed as a means of rapidly identifying patients with acute myocardial infarction who might be eligible for reperfusion therapy. METHODS: The characteristics and outcomes of patients with a prehospital ECG were compared with those without a prehospital ECG in the National Registry of Myocardial Infarction 2 data base. Included in the analysis were those patients who presented to the hospital within 12 h of an acute myocardial infarction. Excluded were patients with an in-hospital infarction, transferred-in referrals and self-transported patients. RESULTS: Prehospital ECGs were obtained in 3,768 (5%) of 66,995 National Registry of Myocardial Infarction 2 patients meeting study criteria. Median time from myocardial infarction symptom onset until hospital arrival was longer among those having a prehospital ECG (152 vs. 91 min, p < 0.001). However, once in the hospital, the prehospital ECG group experienced a shorter median time to the initiation of either thrombolysis (30 vs. 40 min, p < 0.001) or primary angioplasty (92 vs. 115 min, p < 0.001). The prehospital ECG group was more likely to receive thrombolytic therapy (43% vs. 37%, p < 0.001) and to undergo primary angioplasty (11% vs. 7%, p < 0.001). Also, the prehospital ECG group was more likely to undergo coronary arteriography (55% vs. 40%, p < 0.001), angioplasty (24% vs. 16%, p < 0.001) or bypass surgery (10% vs. 6%, p < 0.001). The in-hospital mortality rate was 8% in patients with a prehospital ECG and 12% in those without a prehospital ECG (p < 0.001). After adjusting for baseline covariates utilizing multiple logistic regression analysis, this mortality difference remained statistically significant (odds ratio 0.83, 95% confidence interval 0.71 to 0.96, p = 0.01). CONCLUSIONS: The prehospital ECG is infrequently utilized for diagnosing myocardial infarction, and among patients with a prehospital ECG, is associated with a longer time from symptom onset to hospital arrival. Despite these shortcomings, the prehospital ECG is a test that may potentially influence the management of patients with acute myocardial infarction through wider, faster in-hospital utilization of reperfusion strategies and greater usage of invasive procedures, factors that may possibly reduce shortterm mortality. Efforts to implement the prehospital ECG more widely and more rapidly may be indicated.

Factors influencing the time to thrombolysis in acute myocardial infarction. Time to Thrombolysis Substudy of the National Registry of Myocardial Infarction-1.

BACKGROUND: The Time to Thrombolysis Substudy of the National Registry for Myocardial Infarction provided the opportunity to identify factors that delay thrombolytic treatment of patients with ST-segment elevation acute myocardial infarction. PARTICIPANTS: Forty-two participating registry hospitals volunteered for the Time to Thrombolysis Substudy. METHODS: A case report form was developed to collect time points for emergency department arrival (door), recording of the electrocardiogram (ECG) (data), entry of the order to give a thrombolytic drug (decision), and initiation of the thrombolytic infusion (drug) as defined by the National Heart Attack Alert Program. The impact of mode of transportation to the hospital, sex, policy-driven cardiology consultation and/or contact of the primary care physician on door-to-drug time, and each component interval were determined in 1755 patients who were treated with recombinant tissue-type plasminogen activator (A1-teplase). The t test was used for comparison of means and the nonparametric sign test was used for medians. RESULTS: A minority of patients arrived at the hospital by ambulance, although more women (49.6%) arrived by ambulance than men (40.9%). However, women arrived at hospitals significantly later after onset of symptoms than men. It took half as long for patients arriving by ambulance to be seen by the physician than those who transported themselves to the hospital. It took longer for women to have the initial 12-lead ECG recorded than men. The decision to order a thrombolytic agent was delayed by 22 minutes and median door-to-drug time by 21 minutes in those patients who had a cardiac consultation over those in whom the drug was ordered and infusion was initiated by the emergency physician. Although the initial 12-lead ECG showed ST-segment elevation in 86% of patients who received the thrombolytic drugs, with no difference between men and women and no difference in the rate of cardiology consultation between men and women (77%), door-to-decision time and door-to-drug time were substantially longer for women having consultation than men. There was no significant difference in door-to-decision time between men and women when no consultation was performed, but it still took longer for a drug infusion to be initiated in women. Contacting the primary care physician delayed the decision to give a thrombolytic drug by 18 minutes and the administration of the drug by 20 minutes, but there were no differences between men and women. Preparation of the drug in the pharmacy resulted in significant delay compared with mixing it in the emergency department. CONCLUSIONS: Hospital practices and policies, including contacting the primary care physician prior to the initiation of a lytic drug, cardiology consultation, and preparation of the drug in the pharmacy rather than in the emergency department, significantly delay the goal of early treatment of patients with ST segment elevation acute myocardial infarction. Delays in hospital arrival for women are compounded by delays in the decision to treat them with a thrombolytic drug and initiation of the drug therapy in those women who receive consultation compared with men. Other delays in acquiring the first ECG and initiating the drug infusion in women are not explained.

A composite view of cardiac rupture in the United States National Registry of Myocardial Infarction.

OBJECTIVES: This study was done to determine the incidence, timing and prevalence as a cause of death from cardiac rupture in patients with acute myocardial infarction. BACKGROUND: Several clinical trials and overview analyses have suggested that the survival benefit conferred by thrombolytic therapy may be offset by a paradoxic increase in early deaths from cardiac rupture. METHODS: Demographic, procedural and outcome data from patients with acute myocardial infarction were collected at 1,073 United States hospitals collaborating in the United States National Registry of Myocardial Infarction. RESULTS: Among the 350,755 patients enrolled, 122,243 received thrombolytic therapy. In-hospital mortality for the overall patient population, those not treated with thrombolytics (n = 228,512) and those given thrombolytics were 10.4%, 12.9% and 5.9%, respectively (p<0.001). Cardiogenic shock was the most common cause of death in each patient group. Although the incidence of cardiac rupture was low (<1.0%), it was responsible for 7.3%, 6.1% and 12.1%, respectively, of in-hospital deaths (p<0.001). Death from rupture occurred earlier in patients given thrombolytic therapy, with a clustering of events within 24 h of drug administration. Despite the early risk, death rates were comparatively low in thrombolytic-treated patients on each of the first 30 days. By multivariable analysis, thrombolytics, prior myocardial infarction, advancing age, female gender and intravenous beta-blocker use were independently associated with cardiac rupture. CONCLUSIONS: This large registry experience, including over 350,000 patients with myocardial infarction, suggests that thrombolytic therapy accelerates cardiac rupture, typically to within 24 to 48 h of treatment. The possibility that rupture represents an early hemorrhagic complication of thrombolytic therapy should be investigated.

Factors influencing the time to administration of thrombolytic therapy with recombinant tissue plasminogen activator (data from the National Registry of Myocardial Infarction). Participants in the National Registry of Myocardial Infarction.

Very early administration of thrombolytic therapy for acute myocardial infarction (AMI) has significantly reduced mortality in eligible patients. The purpose of this study was to evaluate factors which influenced the time from symptom onset to hospital presentation and the time from hospital presentation to the onset of thrombolytic treatment in a large population of patients with AMI. This study included 212,990 patients from 904 hospitals that participated in the National Registry of Myocardial Infarction. The median time from symptom onset to hospital presentation for those treated was 1.5 hours versus 2.7 hours for those not receiving thrombolytic treatment. Older patients and women had increased delay times, as did those who arrived at the hospital during daytime hours. Of the 59,802 (28%) patients who received thrombolytic treatment, 23% were treated < 30 minutes from admission; 63%, < 60 minutes; and 83%, < 90 minutes. Time to treatment increased with age and was longer for women and for patients arriving between midnight and early morning. The most important factor associated with shorter time to treatment was the initiation of thrombolytic treatment in the emergency department rather than in the coronary care unit (47 vs 73 minutes, p < 0.0001). Hospital treatment times are much too long, given that quick identification and treatment of eligible patients are of primary importance in reducing mortality from AMI. To shorten these times, thrombolytic treatment should be initiated in the emergency department, and the effectiveness of hospital programs aimed at reducing time to treatment should be subject to continuing quality improvement surveillance.

Treatment of myocardial infarction in the United States (1990 to 1993). Observations from the National Registry of Myocardial Infarction.

BACKGROUND: Multiple clinical trials have provided guidelines for the treatment of myocardial infarction, but there is little documentation as to how consistently their recommendations are being implemented in clinical practice. METHODS AND RESULTS: Demographic, procedural, and outcome data from patients with acute myocardial infarction were collected at 1073 US hospitals collaborating in the National Registry of Myocardial Infarction during 1990 through 1993. Registry hospitals composed 14.4% of all US hospitals and were more likely to have a coronary care unit and invasive cardiac facilities than nonregistry US hospitals. Among 240,989 patients with myocardial infarction enrolled, 84,477 (35.1%) received thrombolytic therapy. Thrombolytic recipients were younger, more likely to be male, presented sooner after onset of symptoms, and were more likely to have localizing ECG changes. Among the 60,430 patients treated with recombinant tissue-type plasminogen activator (rTPA), 23.2% received it in the coronary care unit rather than in the emergency department. Elapsed time from hospital presentation to starting rTPA averaged 99 minutes (median, 57 minutes). Among patients receiving thrombolytic therapy, concomitant pharmacotherapy included intravenous heparin (96.9%), aspirin (84.0%), intravenous nitroglycerin (76.0%), oral beta-blockers (36.3%), calcium channel blockers (29.5%), and intravenous beta-blockers (17.4%). Invasive procedures in thrombolytic recipients included coronary arteriography (70.7%), angioplasty (30.3%), and bypass surgery (13.3%). Trend analyses from 1990 to 1993 suggest that the time from hospital evaluation to initiating thrombolytic therapy is shortening, usage of aspirin and beta-blockers is increasing, and usage of calcium channel blockers is decreasing. CONCLUSIONS: This large registry experience suggests that management of myocardial infarction in the United States does not yet conform to many of the recent clinical trial recommendations. Thrombolytic therapy is underused, particularly in the elderly and late presenters. Although emerging trends toward more appropriate treatment are evident, hospital delay time in initiating thrombolytic therapy remains long, aspirin and beta-blockers appear to be underused, and calcium channel blockers and invasive procedures appear to be overused.