Bryan C. Donohue

Long-term outcome after primary angioplasty: report from the Primary Angioplasty in Myocardial Infarction (PAMI-I) trial

OBJECTIVES This study sought to compare the two-year outcome after primary percutaneous coronary angioplasty or thrombolytic therapy for acute myocardial infarction. BACKGROUND Primary angioplasty, that is, angioplasty without antecedent thrombolytic therapy, has been shown to be an effective reperfusion modality for patients suffering an acute myocardial infarction. This report reviews the two-year clinical outcome of patients randomized in the Primary Angioplasty in Myocardial Infarction trial. METHODS At 12 clinical centers, 395 patients who presented within 12 h of the onset of myocardial infarction were randomized to undergo primary angioplasty (195 patients) or to receive tissue-type plasminogen activator (t-PA) (200 patients) followed by conservative care. Patients were followed by physician visits, phone call, letter and review of hospital records for any hospital admission at one month, six months, one year and two years. RESULTS At two years, patients undergoing primary angioplasty had less recurrent ischemia (36.4% vs. 48% for t-PA, p = 0.026), lower reintervention rates (27.2% vs. 46.5% for t-PA, p < 0.0001) and reduced hospital readmission rates (58.5% vs. 69.0% for t-PA, p = 0.035). The combined end point of death or reinfarction was 14.9% for angioplasty versus 23% for t-PA, p = 0.034. Multivariate analysis found angioplasty to be independently predictive of a reduction in death, reinfarction or target vessel revascularization (p = 0.0001). CONCLUSIONS The initial benefit of primary angioplasty performed by experienced operators is maintained over a two-year follow-up period with improved infarct-free survival and reduced rate of reintervention.

Usefulness of Serum Lipoprotein (a) as a Predictor of Restenosis After Percutaneous Transluminal Coronary Angioplasty

Serum lipoprotein (a) (Lp[a]) has been associated with coronary artery atherosclerosis. Its association with restenosis after percutaneous transluminal coronary angioplasty (PTCA) has not been previously studied. Serum levels of Lp(a), in addition to other lipoproteins, and their components using standard assays, were determined in subjects undergoing cardiac catheterization within 10 months after PTCA. Clinical (e.g., sex, diabetes, angina class) and angiographic (e.g., PTCA percent diameter reduction) factors were not different between the group without (diameter reduction less than 50%; group A) and the group with (diameter reduction greater than or equal to 50%; Group B) restenosis. Total cholesterol, triglycerides, high- and low-density lipoprotein cholesterol, apolipoprotein A-I, apolipoprotein B and Lp(a) were compared. Univariate predictors of restenosis were serum triglycerides (2.50 +/- 1.07 mmol/liter for group A vs 1.72 +/- 0.79 +/- mmol/litre for group B, p = 0.008), and Lp(a) (median: 7.0 mg/dl [range 0 to 44] for group A vs 19 mg/dl [range 1 to 120] for group B; p = 0.006). Stepwise logistic regression revealed the only significant independent predictor of restenosis to be serum Lp(a) (p = 0.018). Each quintile of Lp(a) was associated with a progressively higher risk of restenosis, with the highest quintile (40 to 120 mg/dl) having an odds ratio of 11 (95% confidence interval 9 to 13) compared with the lowest quintile (0 to 3.9 mg/dl) (p = 0.033). A serum Lp(a) of greater than 19 mg/dl was associated with an odds ratio of 5.9 (95% confidence interval 4.6 to 7.2) (restenosis rates of 58% in the group with 0 to 19 mg/dl and 89% in the group with 19 to 120 mg/dl; p = 0.006).(ABSTRACT TRUNCATED AT 250 WORDS)

901-1 A Prospective, Randomized Trial Evaluating Early Discharge (Day 3) without Non-invasive Risk Stratification in Low Risk Patients with Acute Myocardial Infarction: PAMI-2

Few data exist regarding the need for noninvasive testing after reperfusion therapy in myocardial patients at low clinical risk. Moreover, after thrombolysis, recurrent ischemia occurs frequently and unpredictably and has resulted in physician reluctance to shorten the length of hospitalization in these patients. Alternatively, emergency catheterization with primary PTCA may provide acute determination of risk status, a stable method of reperfusion and the potential for early discharge. The objective of this multicenter study was to prospectively test the hypothesis that early discharge (day 3) without noninvasive risk stratification in low risk MI patients treated with primary angioplasty is safe, feasible, and cost effective. Patients with acute myocardial infarction 0–12 hrs who had an emergency catheterization and immediate PTCA of the infarct related artery were stratified into a low risk group if age ≤70 yrs, 1 or 2 vessel disease, EF g 45%, successful infarct vessel PTCA and no malignant arrhythmias persisted after the PTCA. Low risk patients were randomized to admission to either the intensive care unit (with hospitalization a minimum of 5 days and predischarge exercise testing) or admission to a non-intensive care PTCA unit with no non-invasive testing and discharge on day 3. To date, 340 of the anticipated 400 patients have been enrolled. The mean age was 56 ± 9, estimated ejection fraction 56 ± 9 and 74% had single vessel disease. As expected, in-hospital complications occurred infrequently; death 1.1%, recurrent MI 1.7%; stroke 0.6%; heart failure 4.6%. At 1 week follow-up, no complications attributed to early discharge have occurred. Thus, acute catheterization does allow identification of low risk MI patients who can be safely admitted to an elective PTCA unit and discharged in 3 days without additional testing. Complete data on the 400 patient cohort including cost and 6 week follow-up will be available by March 1995.