Search

Objective: Reducing time to reperfusion therapy is one of the goals in the management of acute myocardial infarction (AMI). We assessed the association between timing of aspirin administration and outcome of patients with AMI. Patients: We studied 922 consecutive AMI patients with ST-segment elevation in Killip class I–III on admission. Patients were divided into two groups based upon the timing of emergency aspirin administration: before (early aspirin users) or after (late aspirin users) hospital admission. Results: Early aspirin users (n = 338; 37%) were younger, less likely to be women, and more likely to smoke (p < 0.006) than late users (n = 584; 63%). Other baseline and clinical characteristics were similar. Early aspirin users were more likely to be treated with thrombolysis or primary percutaneous transluminal coronary angioplasty. Compared with late users, early aspirin users had significantly lower in-hospital complications and lower mortality rates at 7 (2.4 vs. 7.3%, p = 0.002) and 30 days (4.9 vs. 11.1%, p = 0.001). By multivariate adjustment, pre-hospital aspirin was an independent determinant of survival at 7 (odds ratio 0.43; 95% confidence interval 0.18–0.92) and at 30 days (odds ratio, 0.60; 95% confidence interval 0.32–1.08). Survival benefit associated with aspirin persisted for subgroups treated or not with reperfusion therapy. Conclusions: Outcome of AMI patients treated with aspirin is improved by pre-hospital administration.Our findings suggest that emergency pre-hospital aspirin might facilitate early reperfusion.

This report describes the effect of age and gender on the results of balloon angioplasty using current technique and indications. A consecutive group of 2,067 patients who underwent angioplasty at a single institution after 1990 is described. Angioplastic success was 92.2% and similar among men and women and the various age groups. Sixteen patients (0.8%) died, and mortality among women was significantly higher (1.4 vs. 0.6%, p0.001). There were no age or gender differences in the rate of Q-wave myocardial infarction and the need for coronary artery bypass. Minor complications such as groin complications (10.5% women, 5.0% men; p0.001) and infections (6.4% women, 3.7% men; p0.05) were more common in women, and as a result the duration of hospitalization after angioplasty was longer. The length of hospitalization after angioplasty was longer with advanced age, mainly as a result of higher groin complications (p0.001), infections (p0.01) and renal failure (p0.05). We conclude that using current indications and technique, angioplasty can be performed safely with a high success rate. Mortality is higher among women. The length of hospitalization after angioplasty is longer in women and, at advanced age, due to higher rate of minor complications.

Coronary restenosis after balloon angioplasty is a slow process that develops over a few months. In some patients, with an initially successful angioplasty, an artery that originally had only moderate stenosis becomes totally occluded as a result of restenosis. This report describes 16 such patients out of 415 dilated lesions with late angiographic follow-up. Ten patients presented with stable angina pectoris, 5 had unstable angina and only one was admitted with a small myocardial infarction. Visible collaterals were present in 15 patients. Except for the patient who sustained myocardial infarction, none of the late angiograms showed the typical morphological features of acute lesion. We conclude that total coronary occlusion late after successful angioplasty of an artery that was moderately narrowed is rare. The 'restenotic' occlusion is a slow process that stimulates collateral formation and thus the risk of myocardial infarction is small.

A 36-year-old patient with normal-appearing coronary arteries suffered an acute Q-wave myocardial infarction during acute alcohol withdrawal and delirium tremens. Sympathetic hyperactivity with coronary spasm and increased platelet reactivity are probably the underlying mechanisms.

We administered 750,000 units of intravenous streptokinase to 121 consecutive patients experiencing their first acute myocardial infarction within 4 h of pain onset. The following information was collected: hours between pain onset and streptokinase administration (TS), hours of pain after streptokinase administration (DP), initial and peak creatine phosphokinase levels (ICK and PCK), time to peak creatine phosphokinase, time to electrocardiographic ST segment resolution. Six days after the infarction, catheterization was performed to calculate ejection fraction, infarct-related regional ejection fraction, and dysfunction index. Data was analyzed using stepwise multiple regression. In patients experiencing anterior infarctions, the following equation was obtained predicting the ejection fraction (EF) with a correlation coefficient of 0.86: EF = 69 - 0.0050(PCK) - 3.7(TS) - 1.8(DP). In anterior infarctions the infarct-related ejection fraction and dysfunction index were similarly predictable. We were slightly less accurate in forecasting the outcome of inferior infarctions. The outcome of intravenous streptokinase therapy can be predicted early in the evolution of acute myocardial infarction using routinely available information.

We compared the effects of verapamil to high dose procainamide on the rate of inducible and spontaneously occurring ventricular tachycardia (VT) in 10 patients. Verapamil induced a significant increase in the rate of tachycardia (R-R interval decreased from 278 +/- 54 to 233 +/- 32 ms, mean +/- SD; p less than 0.025 by paired t test) while procainamide slowed the tachycardia (mean R-R interval was 328 +/- 72 ms, p less than 0.02). Verapamil prevented the induction of sustained VT and was effective as chronic oral antiarrhythmic therapy in 2 patients. The accelerated VT culminated in ventricular fibrillation in 1 patient. It is assumed that verapamil may have either increased conduction velocity or shortened the reentrant cycle. This may be related either to a primary effect of the drug or secondary to increased catecholamine stimulation due to a vasodilatory effect.

Temporal changes in residual stenosis in the infarct-related coronary artery and ventricular function were studied in 30 consecutive patients with an acute myocardial infarction who received rapid, high dose intravenous infusions of streptokinase within 4 h of pain onset. Patients were studied 6 days and 3.9 +/- 1.3 months after the acute episode. Inferior infarction, early thrombolysis (less than 1.5 h after pain onset) and adequate reperfusion (less than 75% residual stenosis in the infarct-related coronary artery) were associated with smaller left ventricular infarcts, smaller ventricular volumes and better ventricular function. Residual stenosis tended to increase with time and in 6 patients the artery closed completely (1 with an overt clinical episode). Ventricular function and volumes improved progressively in patients with good initial function and less residual stenosis in the infarct-related coronary artery.