Initial results, predictors of success, and long-term outcome of primary coronary angioplasty for acute myocardial infarction in a community hospital

Abstract

W favorable results with primary coronary angioplasty (PCA) in patients with acute myocardial infarction (AMI) can be achieved in a community hospital has not been well established. In our community hospital, we have been using PCA as the exclusive reperfusion modality for AMI since 1994. This retrospective study was conducted to analyze our results, including the factors predictive of success and the impact of a successful PCA on hospital stay and on long-term outcome. • • • We retrospectively analyzed 153 consecutive patients who underwent PCA for AMI at our hospital from April 1, 1997 to June 30, 1998. All patients presented to our emergency department within 12 hours of symptom onset with $1 mm of ST-segment elevation in $2 contiguous leads on the initial electrocardiogram. Patients received a chewable adult aspirin (325 mg), weight-adjusted heparin bolus, and b blockers and/or nitrates as determined by their physicians. All patients with persistent angina or elevated ST segments despite initial medical treatment were taken directly to the cardiac catheterization laboratory and constitute the study population. PCA was performed via the percutaneous femoral approach using the standard technique. One of 10 cardiologists with credentials in acute PCA performed the procedure. Glycoprotein IIb/IIIa inhibitors were used at the discretion of the physician, primarily when intracoronary thrombus was identified by angiography. Stents were used at the discretion of the operator. Additional lesions were not treated during the initial procedure. Activated clotting time was maintained at $300 seconds, except when glycoproteins IIb/IIIa inhibitors were administered where it was maintained at $200 seconds using a heparin dosage of 70 U/kg.1 The study protocol was approved by the institutional review board of Lutheran General Hospital. Hospital information was obtained by review of the patient’s medical records. Follow-up information was obtained by telephone contact with a standard questionnaire. Cine angiograms were reviewed by an independent observer blinded to the clinical outcome of the patients and quantitative coronary angiography was done by digital calipers. Procedural success was defined as ,50% residual diameter stenosis and Thrombolysis In Myocardial Infarction (TIMI) 3 flow in the infarct-related artery at the end of the procedure.2 Adverse events were defined as death, reinfarction, and the need for revascularization. Reinfarction was defined as recurrent chest pain with ST/T changes on the electrocardiogram and/or creatine kinase elevation $2 times more than normal with elevated creatine kinase-MB fraction. Categorical variables were compared using the Fisher’s exact or chi-square tests. Continuous variables were analyzed using Student’s 2-tailed t test. Multivariate stepwise logistic regression analysis was used to evaluate the factors affecting procedural success, length of hospital stay, and long-term outcome. Statistical significance was defined as a p value #0.05. Baseline characteristics of the patients are listed in Table 1. Two thirds of the patients were men (mean age 64 years). The median time from onset of chest pain to the first balloon inflation was 265 6 176 minutes. This was significantly shorter in the group with successful than failed PCA (240 6 168 vs 494 6 212 minutes, p ,0.01). At least half of the patients had multivessel disease and most had less than TIMI 3 flow before PCA. Glycoprotein IIb/IIIa inhibitors were given to 59% of patients (90 of 153) and were given to groups with successful and failed PCA with similar frequency (59% vs 64%, p 5 NS). Stents were used in 56% of patients (86 of 153) and were used more frequently in the successful than the failed PCA group (59% vs 28%, p 5 0.02). Stents were not used if angiography revealed vessel diameter ,2.75 mm, in-lesion side branch $2 mm, persistent filling deFrom the Lutheran General Hospital, Park Ridge, Illinois. Dr. Sabri’s address is: Division of Cardiology, Lutheran General Hospital, 1775 Dempster Street, Park Ridge, Illinois 60068. E-mail: nagui.sabri@ advocatehealth.com. Manuscript received July 19, 2000; revised manuscript received and accepted November 21, 2000. TABLE 1 Baseline Characteristics (n 5 153)