Combined cardiac marker approach with adjunct two-dimensional echocardiography to diagnose acute myocardial infarction in the emergency department.

STUDY OBJECTIVE: To evaluate a combined cardiac marker approach with adjunct two-dimensional echocardiography in diagnosing acute myocardial infarction (AMI) in the emergency department. METHODS: This prospective, cohort study enrolled 190 patients aged 18 years and older who presented to the ED of a county teaching hospital and were admitted with chest pain suggestive of AMI. A standardized history and physical examination were performed. Serum sampling for myoglobin and creatine kinase-MB (CK-MB) was done at the time of presentation (time 0) and 3 hours later (time 3 hours). An echocardiographic study was obtained, and a left ventricular wall motion score was derived. RESULTS: Using World Health Organization criteria, 21 patients (11.2%) with AMI were identified. The serum markers were found to be clinically and statistically different between AMI and non-AMI groups at both time 0 and time 3 hours. Receiver operator characteristic curves were used to determine a "positive" myoglobin level at 88.7 ng/mL or higher at either time point, and a "positive" CK-MB level at 11.9 ng/mL or higher; these were used as the optimal cutoff values to predict AMI in the ED. Serum myoglobin was a more sensitive marker (90.5%) than CK-MB (81.0%). However, CK-MB was more specific (99.4%) than myoglobin (88.4%). A combination of both tests, which was rated positive if either test was positive, was a superior predictor overall, with a 100% capture rate of AMI patients and a 91.2% specificity. No significant difference in echocardiographic scores was appreciated in the AMI group compared with the non-AMI group (16.9 +/- 1.5 versus 15.3 +/- .5, respectively; P = .3252). CONCLUSION: Serum myoglobin shows greater sensitivity but is less specific than CK-MB in the early detection of AMI. Use of a combination of both rapid assays during a 3-hour time period in the ED appears to be superior to use of either enzyme assay alone. Two-dimensional echocardiography does not appear to be helpful in diagnosing AMI in the ED.

Cocaine-associated chest pain: one-year follow-up.

OBJECTIVE: To determine the one-year mortality and incidence of myocardial infarction (MI) post-hospital discharge or ED release for patients with cocaine-associated chest pain. METHODS: A prospective, observational study of an inception cohort of consecutive patients who presented to one of four municipal hospital EDs with cocaine-associated chest pain. Patients were followed for one year from the end of the enrollment period. Main outcome parameters were the one-year actuarial survival and the frequency of nonfatal MI. RESULTS: Mortality data were available for all 203 patients at a mean of 408 days. Additional clinical information was available for 185 patients (91%). There were six deaths (one-year actuarial survival 98%; 95% CI, 95-100%); none from MI. Nonfatal MI occurred in two patients (1%; 95% CI, 0-2%). Continued cocaine use was common (60%; 95% CI, 52-68%) and was associated with recurrent chest pain (75% vs 31%, p < 0.0001). No MI or death was reported for patients who claimed to have ceased cocaine use. CONCLUSIONS: Patients who presented with cocaine-associated chest pain commonly continued to use cocaine after discharge. Urgent evaluation of coronary anatomy or cardiac stress tests may not be necessary for patients for whom MI is ruled out and who do not have recurrent potentially ischemic pain. The subsequent risk for MI and death in this group appears to be low. Intervention strategies should emphasize cessation of cocaine use.

Prospective multicenter evaluation of cocaine-associated chest pain. Cocaine Associated Chest Pain (COCHPA) Study Group.

OBJECTIVE: To describe a large cohort of patients who had chest pain following cocaine use, and to determine the incidence of and clinical characteristics predictive for myocardial infarction in this group of patients. METHODS: A prospective observational cohort study of consecutive patients with cocaine-associated chest pain was conducted in six municipal hospital emergency departments (EDs). Demographic variables, drug abuse patterns, medical histories, chest pain characteristics, ECG results, and laboratory data were recorded. Myocardial infarction was the primary endpoint. RESULTS: Fourteen of 246 patients (5.7%; 95% confidence interval [CI], 2.7-8.7%) had myocardial infarction, as diagnosed by elevated CK-MB isoenzyme levels. There were two deaths (0.8%). The patients had a median age of 33 years. The majority were male (71.5%), non-white (83.3%), cigarette smokers (83.3%) who used cocaine regularly. Chest pain began a median of 60 minutes after cocaine use and persisted for a median of 120 minutes. Chest pain was most frequently described as substernal (71.3%) and pressure-like (46.7%). Shortness of breath (59.3%) and diaphoresis (38.6%) were common. There was no clinical difference between patients who had myocardial infarctions and those who did not. Twelve patients had arrhythmias and four had congestive heart failure. All cases requiring intervention were evident upon presentation. An ECG revealing ischemia or infarction had a sensitivity of 35.7% for predicting a myocardial infarction. The specificity, positive predictive value, and negative predictive value of the ECGs were 89.9%, 17.9%, and 95.8%, respectively. CONCLUSIONS: Myocardial infarction in patients who have cocaine-associated chest pain is not uncommon. No clinical parameter available to the physician can adequately identify patients at very low risk for myocardial infarction. Therefore, all patients with cocaine-associated chest pain should be evaluated for myocardial infarction.

Nitroglycerin in the treatment of cocaine associated chest pain--clinical safety and efficacy.

The optimal medical regimen for the treatment of cocaine associated myocardial ischemia has not been defined. While animal and human data demonstrate the risks of beta-adrenergic blockade, studies in the cardiac catheterization laboratory suggest a beneficial role of nitroglycerin. We performed a prospective multicenter observational study to evaluate the clinical safety and efficacy of nitroglycerin in the treatment of cocaine associated chest pain at six municipal hospital centers. Of 246 patients presenting with cocaine associated chest pain, 83 patients were treated with nitroglycerin at the discretion of the treating physician. Relief of chest pain and/or adverse hemodynamic outcome were the primary endpoints. Baseline comparisons of patients treated with nitroglycerin to those not treated with nitroglycerin found that the treated patients were at higher risk of ischemic heart disease. They were older (36 years vs 32 years, p = 0.0008), more likely to have an ischemic electrocardiogram (27% vs 4%, p < 0.0001), to be admitted (94% vs 40%, p < 0.0001), and to have a discharge diagnosis of ischemic heart disease (41% vs 9%, p < 0.0001). Nitroglycerin was beneficial in 41 patients (49%; 95% CI, 38-60%): 37 patients (45%) had relief or reduction in the severity of chest pain and 4 patients (5%) had other beneficial effects. Only one patient had an adverse outcome (transient hypotension in the setting of a right ventricular infarct). Nitroglycerin is safe and possibly effective in the treatment of cocaine associated chest pain.