Early clinical outcomes and routine management of patients with non-ST-segment elevation myocardial infarction: a nationwide perspective

BACKGROUND: Myocardial infarction (MI) in the absence of electrocardiographic ST-segment elevation or new bundle branch block is the cause of hospitalization for a large and steadily increasing proportion of patients with acute ischemic chest pain. Despite its prevalence, the common demographic features, current hospital-based management, and short-term clinical outcome among patients with non-ST-segment elevation MI remain poorly defined. METHODS: A total of 183 113 patients with non-ST-segment elevation MI were identified in the National Registry of Myocardial Infarction database. Using a validated model, 43 928 patients (24.0%) were retrospectively placed in major, 34 917 (19.1%) in intermediate, and 104 268 (56.9%) in minor severity clinical event categories that included hospital death, recurrent myocardial ischemia, and nonfatal recurrent MI. RESULTS: The administration of widely available and universally recommended pharmacologic therapies, including aspirin and beta-adrenergic blocking agents, was suboptimal, particularly among patients with major severity clinical events. In contrast, coronary angiography and mechanical revascularization procedures were commonplace (\u3e60% of all patients) and most frequently performed in patients within the minor (compared with the major) severity clinical event category (58.2% and 42.7%, respectively). CONCLUSIONS: Patients with non-ST-segment elevation MI are a heterogeneous population, with readily identifiable demographic characteristics and clinical features associated with important early outcomes, including death. Nationwide efforts directed toward maximizing pharmacologic therapy utilization and the performance of invasive procedures according to established guidelines must continue

Prevalence, clinical characteristics, and mortality among patients with myocardial infarction presenting without chest pain

CONTEXT: Although chest pain is widely considered a key symptom in the diagnosis of myocardial infarction (MI), not all patients with MI present with chest pain. The extent to which this phenomenon occurs is largely unknown. OBJECTIVES: To determine the frequency with which patients with MI present without chest pain and to examine their subsequent management and outcome. DESIGN: Prospective observational study. SETTING AND PATIENTS: A total of 434,877 patients with confirmed MI enrolled June 1994 to March 1998 in the National Registry of Myocardial Infarction 2, which includes 1674 hospitals in the United States. MAIN OUTCOME MEASURES: Prevalence of presentation without chest pain; clinical characteristics, treatment, and mortality among MI patients without chest pain vs those with chest pain. RESULTS: Of all patients diagnosed as having MI, 142,445 (33%) did not have chest pain on presentation to the hospital. This group of MI patients was, on average, 7 years older than those with chest pain (74.2 vs 66.9 years), with a higher proportion of women (49.0% vs 38.0%) and patients with diabetes mellitus (32.6% vs 25. 4%) or prior heart failure (26.4% vs 12.3%). Also, MI patients without chest pain had a longer delay before hospital presentation (mean, 7.9 vs 5.3 hours), were less likely to be diagnosed as having confirmed MI at the time of admission (22.2% vs 50.3%), and were less likely to receive thrombolysis or primary angioplasty (25.3% vs 74.0%), aspirin (60.4% vs 84.5%), beta-blockers (28.0% vs 48.0%), or heparin (53.4% vs 83.2%). Myocardial infarction patients without chest pain had a 23.3% in-hospital mortality rate compared with 9.3% among patients with chest pain (adjusted odds ratio for mortality, 2. 21 [95% confidence interval, 2.17-2.26]). CONCLUSIONS: Our results suggest that patients without chest pain on presentation represent a large segment of the MI population and are at increased risk for delays in seeking medical attention, less aggressive treatments, and in-hospital mortality. JAMA. 2000;283:3223-322

National Heart Attack Alert Program position paper: chest pain centers and programs for the evaluation of acute cardiac ischemia

The National Heart Attack Alert Program (NHAAP), which is coordinated by the National Heart, Lung, and Blood Institute (NHLBI), promotes the early detection and optimal treatment of patients with acute myocardial infarction and other acute coronary ischemic syndromes. The NHAAP, having observed the development and growth of chest pain centers in emergency departments with special interest, created a task force to evaluate such centers and make recommendations pertaining to the management of patients with acute cardiac ischemia. This position paper offers recommendations to assist emergency physicians in EDs, including those with chest pain centers, in providing comprehensive care for patients with acute cardiac ischemia

Use of emergency medical services in acute myocardial infarction and subsequent quality of care: observations from the National Registry of Myocardial Infarction 2

BACKGROUND: National practice guidelines strongly recommend activation of the 9-1-1 Emergency Medical Systems (EMS) by patients with symptoms consistent with an acute myocardial infarction (MI). We examined use of the EMS in the United States and ascertained the factors that may influence its use by patients with acute MI. METHODS AND RESULTS: From June 1994 to March 1998, the National Registry of Myocardial Infarction 2 enrolled 772 586 patients hospitalized with MI. We excluded those who transferred in, arrived at the hospital \u3e6 hours from symptom onset, or who were in cardiogenic shock. We compared baseline characteristics and initial management for patients who arrived by ambulance versus self-transport. EMS was used in 53.4% of patients with MI, a proportion that did not vary significantly over the 4-year study period. Nonusers of the EMS were on average younger, male, and at relatively lower risk on presentation. In addition, payer status was significantly associated with EMS use. Use of EMS was independently associated with slightly wider use of acute reperfusion therapies and faster time intervals from door to fibrinolytic therapy (12.1 minutes faster, P\u3c0.001) or to urgent PTCA (31.2 minutes faster, P\u3c0.001). CONCLUSIONS: Only half of patients with MI were transported to the hospital by ambulance, and these patients had greater and significantly faster receipt of initial reperfusion therapies. Wider use of EMS by patients with suspected MI may offer considerable opportunity for improvement in public health