Improvement in long-term prognosis of elderly patients with acute myocardial infarction after the introduction of intravenous thrombolytic therapy

Survival rate from a "thrombolytic" period of 351 patients above 66 years of age with acute myocardial infarction (AMI) was compared with that of 289 patients from a "prethrombolytic" period. The two groups were comparable regarding sex, age, previous AMI, cerebrovascular events, morbidity and mortality during admission. Survival rates after four years were 45.0% in the "thrombolytic" group and 38.4% in the "prethrombolytic" group (p = 0.047, log rank test). Using the Cox proportional hazard analysis, thrombolytic therapy was shown to be an independent prognostic predictor in "the thrombolytic population" with a relative risk of death from day 30 to end of follow-up of 0.4 (95% confidence interval 0.2-0.8). No interaction was found between age and thrombolysis. Although only one-fifth of the patients with AMI were eligible for thrombolysis, this treatment may have contributed to the improved long-term survival.     

Does PTCA in acute myocardial infarction affect mortality and reinfarction rates? A quantitative overview (meta-analysis) of the randomized clinical trials

BACKGROUND: Percutaneous transluminal coronary angioplasty (PTCA) is often performed after acute myocardial infarction (AMI) either as an adjuvant to thrombolytic therapy or instead of thrombolysis. The effect of PTCA in AMI on mortality and reinfarction has remained unclear, with the available randomized trials indicating inconsistent results. METHODS AND RESULTS: A systematic overview (meta-analysis) of the randomized trials was conducted to assess the effect of PTCA in AMI on mortality and reinfarction rates. Data from 7 trials in which primary PTCA was evaluated and 16 trials in which PTCA after thrombolysis was studied were included in this overview, comprising a total of 8496 patient. The trials represented different approaches to the timing of PTCA after AMI. The trials of PTCA after thrombolytic therapy were also categorized according to the different protocols with respect to the routine or elective character of PTCA in the invasive group. A reduction in short-term (6 week) mortality (odds ratio, 0.56; 95% CI, 0.33, 0.94) and in the combined outcome of short-term mortality and nonfatal reinfarction (odds ratio, 0.53; 95% CI, 0.35, 0.80) was observed in the trials comparing primary PTCA with thrombolytic therapy. In contrast, in trials in which an approach of thrombolysis and PTCA was compared with thrombolytic therapy alone, there was no important difference in early mortality, with an apparent reduction in mortality between 6 and 52 weeks. The lower mortality between 6 and 52 weeks among 6-week survivors seemed to be restricted to the subgroup of trials in which PTCA was used as a routine strategy (odds ratio, 0.58; 95% CI, 0.39, 0.87). CONCLUSIONS: Although the analyses of the various categories of trials suggest that primary PTCA may be more beneficial than thrombolytic therapy in AMI, these data should be interpreted cautiously unless confirmed by larger studies. In contrast, the addition of various other strategies of PTCA to thrombolytic therapy does not convincingly indicate a clinically different outcome than if a more conservative strategy is followed, in which PTCA is used only if clinically indicated. Some specific strategies, however, such as rescue PTCA in high-risk patients with occluded arteries, may be of benefit.     

Thrombolytic therapy in acute occlusion of the intracranial internal carotid artery bifurcation

PURPOSE: To evaluate efficacy and clinical benefit of early thrombolytic therapy in intracranial internal carotid artery occlusion. METHODS: Thirty-two patients (mean age, 56 years) with acute intracranial internal carotid artery occlusion were studied clinically and with CT and angiography before and after thrombolytic therapy with intravenous alteplase (n = 16), superselective intraarterial alteplase (n = 8), and superselective intraarterial urokinase (n = 8). RESULTS: Initial CT showed a large parenchymal hypodensity in 11 (34%) patients, a small hypodensity in 15 (47%) patients, and no hypodensity in 6 (19%) patients. Recanalization after thrombolytic therapy was observed in 4 patients (12.5% in each treatment group). Follow-up CT showed six hemorrhagic infarcts and four parenchymal hematomas unrelated to recanalization, alteplase, or urokinase administration, but commonly associated with intraarterial treatment. Clinical outcome was fatal in 53%, poor in 31%, and moderate or good in 16% of the patients. Outcome was equal in different treatment groups and closely linked to both the quality of leptomeningeal collaterals and the extent of parenchymal hypodensity on the first CT. CONCLUSION: Because intravenous or intraarterial treatment with alteplase or urokinase fails to recanalize the vascular obstruction, it does not improve the prognosis of intracranial internal carotid artery occlusion over that of the natural course. Improved results may be possible with novel recanalization techniques.     

Pharmacologic profile of survivors of acute myocardial infarction at United States academic hospitals

Optimal drug therapy for patients with acute myocardial infarction (AMI) is well described in the medical literature. However, data on the actual pharmacologic management of patients surviving AMI at academic hospitals is unavailable. The purpose of this study was to document treatment profiles in 500 patients surviving AMI at 12 academic hospitals in the United States. These profiles were compared with established guidelines and were evaluated for trends. Overall, thrombolytics (streptokinase > or = tissue-type plasminogen activator) were administered in 29% of the patients, with a greater proportion of patients receiving beta-blockers than calcium channel antagonists in the initial 72 hours (61% vs 40%; p < 0.005) and at discharge (51% vs 35%; p < 0.005). Further, women were less likely than men to receive thrombolytic therapy (odds ratio [OR] = 0.61; confidence interval [CI], 0.54 to 0.69) or beta-blocker therapy within the first 72 hours (OR = 0.61; CI, 0.55 to 0.67) or at hospital discharge (OR = 0.53; CI, 0.48 to 0.58). Overall, improvements could still be made in the number of patients who receive thrombolytic and acute and chronic beta-blocker therapies after AMI, particularly in women. Changes in treatment profiles may be a reflection of the publication of large clinical trials.     

Thrombolytic therapy compared with mechanical recanalization in non-acute peripheral arterial occlusions: a randomized trial

PURPOSE: To evaluate whether thrombolytic therapy followed by angioplasty has any added benefit compared with angioplasty alone for the treatment of chronic peripheral arterial occlusions. PATIENTS AND METHODS: Twenty patients with claudication or limb-threatening ischemia of at least 3 weeks duration due to iliac or femoropopliteal artery occlusions were randomized either to thrombolytic therapy with recombinant tissue-type plasminogen activator for up to 4 hours (n = 11) followed by angioplasty or to angioplasty alone (n = 9). Clinical follow-up was obtained for 1 year. RESULTS: Life-table analysis revealed a significant improvement in the cumulative primary patency rate for patients with claudication treated initially with thrombolysis followed by angioplasty (n = 7; 86% at 6 months; 51% at 1 year) compared with angioplasty alone (n = 9; 11% at 6 months and 1 year) (P < .02). All four patients with limb-threatening ischemia were randomized to thrombolytic therapy, and none exhibited continued patency at 1 year. The most common complication in the thrombolysis group was peripheral embolization; three of these four patients were among those who had limb-threatening ischemia as the indication for entry into this study. There was no increased incidence of bleeding with thrombolytic therapy. CONCLUSIONS: A short course of thrombolytic therapy prior to angioplasty appears to improve the 1-year patency rate for claudication due to iliac or femoropopliteal occlusions. However, patients with limb-threatening ischemia have a high prevalence of peripheral embolization and dismal patency rates with this form of therapy. A larger scale study is necessary to confirm these findings.     

Danish multicenter randomized study of invasive versus conservative treatment in patients with inducible ischemia after thrombolysis in acute myocardial infarction (DANAMI). DANish trial in Acute Myocardial Infarction

BACKGROUND: The aim of the DANish trial in Acute Myocardial Infarction (DANAMI) study was to compare an invasive strategy of percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG) with a conservative strategy in patients with inducible myocardial ischemia who received thrombolytic treatment for a first acute myocardial infarction (AMI). METHODS AND RESULTS: Of the 503 patients randomized to an invasive strategy, PTCA was performed in 266 (52.9%) and CABG in 147 (29.2%) from 2 to 10 weeks after the AMI. Of the 505 patients in the conservative treatment group, only 8 (1.6%) had been revascularized 2 months after the AMI. The patients were followed up from 1 to 4.5 years. The primary end points were mortality, reinfarction, and admission with unstable angina. At 2.4 years' follow-up (median), mortality was 3.6% in the invasive treatment group and 4.4% in the conservative treatment group (not significant). Invasive treatment was associated with a lower incidence of AMI (5.6% versus 10.5%; P=.0038) and a lower incidence of admission for unstable angina (17.9% versus 29.5%; P<.00001). The percentages of patients with a primary end point were 15.4% and 29.5% at 1 year, 23.5% and 36.6% at 2 years, and 31.7% versus 44.0% at 4 years (P=<.00001) in the invasive and conservative treatment groups, respectively. At 12 months, stable angina pectoris was present in 21% of patients in the invasive treatment group and 43% in the conservative treatment group. CONCLUSIONS: Invasive treatment in post-AMI patients with inducible ischemia results in a reduction in the incidence of reinfarction, fewer admissions due to unstable angina, and lower prevalence of stable angina. We conclude that patients with inducible ischemia before discharge who have received treatment with thrombolytic drugs for their first AMI should be referred to coronary arteriography and revascularized accordingly.     

Thrombolysis in myocardial infarction-outcome optimization methods

Early reperfusion in acute myocardial infarction (AMI) has been shown to reduce the extent of myocardial necrosis and to improve short and long term prognosis. Gender, smoking, age and site of infarct location may be regarded as prognostic factors for the outcome of AMI and of thrombolytic therapy with streptokinase (STK). The aim of this study was to identify factors, which are related to the results of thrombolytic therapy by STK in AMI. 156 patients (122 males and 34 females) treated with STK were retrospectively analyzed: they were subdivided into 3 groups according to the presumed success of thrombolytic therapy based on the accepted clinical and angiographic TIMI flow criteria. Group 1 = successful (88 patients), group 2 = probably successful (20 patients) and group 3 = failed thrombolysis (48 patients). Multiple regression analysis showed that Killip class (p = 0.0005), time from pain onset to thrombolysis initiation (p = 0.02) and the time of the day in which thrombolysis began (p = 0.037) are independent major predictive factors for successful thrombolytic therapy by STK in AMI. Gender, age, smoking and some risk factors are not of similar predictive power. These results may guide us in the optimization of thrombolytic therapy by STK in AMI, different dose regimens for different times of day and probably preference for primary PTCA in the early morning hours.     

The challenge and importance of defining critical limb ischemia

Thrombolytic therapy (TT) modifies the natural history of acute myocardial infarction (AMI) diminishing morbi-mortality rate. In recent studies, modification of infusion velocity, decreased the mortality 10 percentage points. OBJECTIVE: Test if rt PA administration over an hour is safe and practical. MATERIAL AND METHODS: A prospective, cooperative trial during 3 years, included patients with AMI with less than 6 hours of the onset of symptoms that received rt-PA therapy. Initially 10 mg bolus and then 90 mg over 60 minutes period. Together with the administration of rt-PA, 5000 units of heparin was given, followed by 1000 units per hour adjusted to keep PTT at 1.5 to 2 times normal. All patients received aspirin and according of the evolution adjuvant therapy. We defined bleeding complications and/or cerebrovascular accident related to thrombolytic therapy. RESULTS: We included 225 patients who received rt-PA. Average age was 57.1 +/- 22.2 years, 78.7% males and 21.3% females. Arrival time at hospital was 2.93 +/- 1.7 hours. 82.2% were in class I-II by NYHA. 59.2% had anterior wall location and 32.4% posterior-inferior wall 80% had reperfusion criteria. Only 7.1% required transfusion and 0.4% presented CNS bleeding. The survival rate was 95.2%. The mortality had no relation with bleeding. CONCLUSION: Fast infusion is an effective and safe method. Transfusion requirements are no greater, and CNS bleeding was noted in 0.4% of the cases.     

Hospital course of acute myocardial infarction: significance of the therapeutic procedures of early reperfusion

Reperfusion therapy has contributed to decreased morbidity and mortality in patients with acute myocardial infarction (AMI). Implementation of thrombolytic therapy; primary angioplasty and emergency coronary artery by-pass surgery have proved to be effective in well designed controlled clinical trials. There is little information, however, about the impact of reperfusion therapy in the general clinical population that is usually seen in the coronary care unit. In this paper we have compared the clinical course, morbidity and mortality of patients attended for a first AMI in 2 different periods. Group I comprised 431 patients seen during the period 1981-1986 and group II bad 113 patients seen during the period 1992-1993. Age, gender distribution and AMI location were similar in both groups. Patients in group I had a significantly higher incidence of tobacco use and previous angina pectoris. In group I, 4% of patients received streptokinase, 0.9% of patients had emergency by-pass surgery and none had primary angioplasty, whereas in group II, 29% of patients received trombolytics, 6.5% had primary angioplasty and 6.5% had by-pass surgery. Heart failure Killip class II-III occurred in 35% of patients in group I and in 13% of patients in group II (p < 0.05). Intrahospital mortality was 19.6% in group I and 11.5% in Group II (p < 0.045). There were no differences in the incidence of cardiogenic shock in both groups. Multivariate analysis showed that age and heart failure were significant independent predictors of mortality in both periods. Thus, there has been a significant change in the therapeutic approach to AMI patients in recent years. Widespread utilization of reperfusion therapy appears to be associated with decrease in morbidity and mortality in a general population of patients with a first AMI.     

Thrombolytic therapy does not change the release ratios of enzymatic and non-enzymatic myocardial marker proteins

Measurements of cardiac marker proteins in plasma from patients with acute myocardial infarction (AMI) have become important in the evaluation of recanalization therapy. The validity of this approach has however been questioned, because it was claimed that coronary reperfusion may increase the recovery in plasma of cardiac enzymes, such as creatine kinase (CK). In the present study, possible effects of thrombolytic therapy on the release of enzymatic and nonenzymatic marker proteins were investigated. Activities of CK and lactate dehydrogenase (LDH), and concentrations of myoglobin (Mb) and fatty acid-binding protein (FABP) were determined in serial plasma samples obtained from 50 patients with confirmed AMI, of whom 36 received thrombolytic therapy, and 14 did not. Treatment delay was 2.8+/-1.6 (mean+/-SD) h, and hospital delay in untreated patients was 2.7+/-1.8 h. Average infarct size, expressed in gram-equivalents of heart muscle per litre of plasma (g-eq/l), varied between 5.5 and 7.2 g-eq/l for the four marker proteins in patients treated with thrombolytic therapy, and between 4.6 and 6.4 g-eq/l in untreated patients, with a tendency to larger infarct sizes for Mb and FABP than for CK and LDH. Thrombolytic therapy, although significantly accelerating protein release rates, did not influence the release ratios. These results indicate that thrombolytic therapy has no significant effects on the recovery of cardiac marker proteins in plasma.     

Usefulness of ST-segment depression in non-infarct-related electrocardiographic leads in predicting prognosis after thrombolytic therapy for acute myocardial infarction

This study investigated both the in-hospital and long-term prognostic significance of ST-segment depression in non-infarct-related leads in patients who received thrombolytic therapy after acute myocardial infarction (AMI). We evaluated 221 consecutive patients who were admitted with their first AMI and underwent thrombolysis. Patients were followed for an average of 31 months and were classified into 3 groups: group 1 included 51 patients with persistent ST-segment depression, group 2 had 97 patients with transient ST-segment depression, and group 3 consisted of 73 patients without ST-segment depression (absent). Group 1 had significantly worse long-term survival during follow up by Kaplan-Meier analysis (55%) versus group 2 (81%) and group 3 (94%) (p = 0.0004) and higher event rates. This prognostic significance seemed to be maintained in both the anterior and inferior wall AMI groups. Multivariate analysis, using the Cox model, showed that Killip class, in-hospital left ventricular ejection fraction, and the persistence of ST-segment depression on the predischarge electrocardiogram (group 1) were independent predictors of survival. ST-segment depression in non-infarct-related leads on the predischarge electrocardiogram is an independent risk factor for worse long-term survival after anterior as well as inferior AMI treated with thrombolytic therapy.     

Adjuvant therapy in patients with acute myocardial infarct

Besides the thrombolytic therapy several adjuvant therapeutic measures were identified which significantly improve the prognosis of patients with acute myocardial infarction (AMI). These measures include the treatment by means of acetylsalicylic acid (ASA), beta-blockers and ACE inhibitors. Early administration of ASA and beta-blockers are indicated in all patients with AMI who have no contraindications for this therapy. They are especially the patients with manifest heart failure or asymptomatic left ventricular dysfunction who benefit from ACE inhibitors. The effectivity of routine administration of other medicaments such as anticoagulants, nitrates, calcium channel blockers and magnesium, have not been convincingly proved. However, some selected patients with AMI can benefit from these medicaments. Intravenous administration of heparin is unambiguously justified only in thrombolysis with t-PA. Thrombolyses with streptokinase, urokinase, and anistreplase are justified only at high risk of thromboembolic complications. Their prevention and therapy include also the necessity to restrict the administration of pelentan. The use of nitrates is indicated in patients with AMI in case of sustaining stenocardia, arterial hypertension and manifest heart left ventricular failure. Until the definitive standpoint is gained regarding the effect of magnesium in patients with AIM, its administration remains especially indicated in cases of arterial hypertension, tachycardiac disturbances of the heart rhythm and states of assumed or proved hypomagnesiemia. In AMI cases when magnesium is used in order to protect the patient from reperfusion lesion, it must be administered prior to the reperfusion therapy. An intensive research in the field of therapeutical measures in patients with AMI still continues. It is certain that it will soon bring further knowledge which will in turn improve the prognosis and quality of life of patients with AMI. (Tab. 4, Ref. 133.)     

Streptokinase-induced activation of the kallikrein-kinin system and of the contact phase in patients with acute myocardial infarction

Thrombolytic therapy in acute myocardial infarction (AMI) is hampered by a considerable reocclusion rate. Thrombin activity is enhanced, and contact-system activation via plasminemia might be possible. Prospectively we examined the contact phase and the kallikrein-kinin system and additional molecular markers of hemostasis and fibrinolysis in AMI. In 22 patients with AMI, blood sampling was performed at admission and < or =10 days afterward. Eleven patients received 1.5 Mio U streptokinase (group A) and were compared with 11 AMI patients without thrombolytic therapy (group B). All patients had systemic heparinization (5,000 IU bolus, i.v.; 1,000 IU/h, i.v.). In group A (vs. group B), the kallikrein-factor XII system was significantly activated (3 h after start of therapy): kallikrein activity 140 +/- 41 (vs. 43 +/- 8) U/L (p < 0.05); kallikrein inhibition 87 +/- 9 (vs. 113 +/- 7%; p < 0.05), and factor XII 70 +/- 14 (vs. 94 +/- 6%). C1 inhibitor and factor XII inhibition were decreased. High-molecular-weight kininogen consumption indicating bradykinin generation was enhanced (p < 0.01). In group A, thrombin activity (TAT) was increased, and a hypercoagulative state with increased fibrin degradation products (d-dimer) was found. Plasmin activation in group A was reflected by decreased plasminogen and antiplasmin levels (p < 0.01). The findings indicate that streptokinase induces activation of the contact phase-kinin system in vivo associated with a consecutive increase of thrombin and bradykinin generation. Activation of this pathway might substantially contribute to reocclusion after initially successful thrombolytic therapy and to hypotensive reactions observed after streptokinase.     

Prehospital management of acute myocardial infarction: Electrocardiogram acquisition and interpretation, and thrombolysis by prehospital care providers

OBJECTIVE: To review prehospital management of patients with suspected ST elevation acute myocardial infarction (AMI) based on the acquisition and interpretation of electrocardiograms (ECGs), and the effects of thrombolytic therapy initiated by prehospital care providers. DESIGN: MEDLINE was searched by combining the search phrases 'thrombolysis,' 'paramedics' and 'myocardial infarction' to identify all pertinent articles. The bibliographies were reviewed to search for other relevant articles. RESULTS: The earlier that treatment is initiated in AMI, the better the prognosis. Multiple randomized and nonrandomized trials indicate that prehospital care providers (including paramedics, nurses and doctors) are able to acquire prehospital ECGs with negligible increases in on-scene time, ranging from 30 s to 7 mins. With minimal training, they are capable of accurately interpreting ECGs and diagnosing ST elevation AMI, with results comparable with control ECGs obtained by physicians. Numerous studies have investigated the role of specially trained prehospital personnel in initiating thrombolysis. Trials outside of North America have predominantly used physicians, whereas North American studies employed paramedics. Thrombolysis has been shown to be safe and effective when started outside the hospital by physicians or paramedics, with a reduction in time to treatment and no increase in complications. The further a patient with ST elevation AMI is from hospital, the greater the potential benefit of prehospital thrombolysis. The European Myocardial Infarction Project (EMIP), the largest randomized trial of prehospital thrombolysis, demonstrated a trend towards reduced mortality but was underpowered to detect significant mortality differences. The Grampian Region Early Anistreplase Trial (GREAT), a rural study, is the only randomized trial to demonstrate a statistically significant mortality difference in patients receiving prehospital thrombolysis. Despite trends in favour of prehospital diagnosis and treatment of AMI, no urban study has been sufficiently powered to demonstrate mortality benefits. CONCLUSION: Prehospital treatment of patients with chest pain using ECGs and thrombolysis is safe. Though rural patients have significant reductions in total mortality when treated with thrombolysis in a prehospital setting, this has not been documented with an urban population. Prehospital identification of thrombolysis-eligible patients with ST elevation AMI via acquisition and interpretation of ECGs followed by triage to a hospital 'lytic team' has the potential to improve patient outcome and requires further investigation. A prehospital paramedic program for identifying and treating thrombolysis-eligible patients requires intensive planning, retrospective feasibility work, implementation and monitoring to establish effectiveness.     

Percutaneous transluminal coronary angioplasty (PTCA) as primary therapy in acute myocardial infarct

BASIC PROBLEM AND OBJECTIVE: Percutaneous transluminal coronary angioplasty (PTCA) is being increasingly considered as an alternative to thrombolytic treatment of acute myocardial infarction. Studies performed so far, some on selected groups of patients, have produced high initial results of success. This prospective study was undertaken to determined primary success, complications and recurrence after primary PTCA in acute myocardial infarction (AMI). PATIENTS AND METHODS: Primary treatment in the form of immediate PTCA of the infarct vessel was undertaken in 111 patients (84 men, 27 women; mean age 58.6 +/- 10.3 years) with AMI. PTCA was judged successful if the infarct vessel had been reopened to perfusion grade 3 and restenosis was < 50%. No thrombolytic treatment was given, but heparin infusions were given during and for 24-48 hours after the procedure. 13 patients (11.7%) were in cardiogenic shock or required cardiopulmonary resuscitation for infarct-related arrhythmias. RESULTS: The primary success rate of PTCA for the whole group was 91% (101 of 111 patients), but only 77% (ten of 13) among patients in cardiogenic shock and (or) after resuscitation. Acute re-occlusion (0-6 days after PTCA) occurred in seven patients. Eight patients (7.2%) died during the hospital phase (0-4 weeks), seven of whom had been in shock or required resuscitation (death rate 54%). The overall complication rate of the intervention was 6.3%. No emergency aortocoronary bypass was necessary. Repeat coronary angiography was performed in 71 of the 101 successfully treated patients 6 or 12 weeks after the PTCA. Re-occlusion was demonstrated in four (5.6%), a restenosis of more than 50% in 25% of patients. Mean left ventricular ejection fraction, obtained by planimetry from the levocardiogram was 58.6 +/- 9.3%. CONCLUSION: PTCA, performed immediately after acute myocardial infarction is an effective therapeutic measure with a high primary success rate.     

Comparison of mortality from acute myocardial infarction between 1979 and 1992 in a geographically defined stable population

This study documents mortality from acute myocardial infarction (AMI), in hospital and at 1 year, for each of 3 selected 1-year periods in a stable community over a 13-year period beginning in 1979 and continuing into the thrombolytic era, to detect any changes occurring in conjunction with the introduction of new therapies. Every patient with AMI occurring in a geographically defined stable community (Hamilton, Ontario, Canada) in 3 1-year periods (1979 to 1980 [n = 816], 1986 to 1987 [n = 816], and 1991 to 1992 [n = 831]) was identified and clinically characterized by standardized criteria. Subsequent in-hospital and 1-year survival were ascertained prospectively. The 3 cohorts were similar in prognostic factors. Mean age was progressively greater over the study period from 63 years in 1979 to 1980, to 67 years in 1991 to 1992 (p = 0.02). There was no change in in-hospital mortality rates from 1979 to 1980 (17%) and 1986 to 1987 (16%). However, from 1986 to 1987 and 1991 to 1992, in-hospital mortality decreased from 16% to 9% (p < 0.001) and 1-year mortality decreased from 26% to 19% (p < 0.001). For patients who survived the hospital phase of AMI, 1-year mortality did not change and was between 11% and 12% in each of the 3 study periods. From 1986 to 1987 and 1991 to 1992, there was an increase in the use of thrombolytic therapy from 5% to 44% of patients. The acute use of aspirin increased from 30% to 88% and the acute use of beta blockers increased from 19% to 48% of patients. The observed increase in use of these agents could account for half of the actual mortality reduction observed. This prospective population-based survey demonstrates improved in-hospital survival after AMI associated with increased use of established effective therapies between 1987 and 1992. The 1-year mortality of hospital survivors of AMI was unchanged throughout the period of study, remaining at 11% to 12%.     

Randomized trial of direct coronary angioplasty versus intravenous streptokinase in acute myocardial infarction

OBJECTIVES: The objective of this study was to obtain preliminary data on the relative clinical utility of direct coronary angioplasty compared with that of intravenous thrombolytic therapy for patients with acute myocardial infarction. BACKGROUND: The relative merits of intravenous thrombolytic therapy and direct coronary angioplasty as treatment for acute myocardial infarction are incompletely understood, and randomized trials of these treatments have been extremely limited. METHODS: One hundred patients with ST segment elevation presenting to a single high volume interventional center within 6 h of the onset of chest pain were randomized to receive either streptokinase (1.2 million U intravenously over 1 h) or immediate catheterization and direct coronary angioplasty. Patients were excluded for age > or = 75 years, prior bypass surgery, Q wave infarction in the region of ischemia or excessive risk of bleeding. All patients were then treated with aspirin (325 mg orally/day) and heparin (1,000 U intravenously/h) for 48 h until catheterization was performed to determine the primary study end point, namely, infarct-related artery patency at 48 h. Secondary end points were in-hospital death, left ventricular ejection fraction at 48 h and time to treatment. RESULTS: There was no difference in the baseline characteristics of the two treatment groups. Overall patient age was 56 +/- 10 years, 83% of patients were male, 11% had prior infarction, 40% had anterior infarction and 97% were in Killip class I or II. Although time to treatment was delayed in the angioplasty group (238 +/- 112 vs. 179 +/- 98 min, p = 0.005), there was no difference in 48-h infarct-related artery patency or left ventricular ejection fraction (patency 74% vs. 80%; ejection fraction 59 +/- 13% vs. 57 +/- 13%; angioplasty vs. streptokinase, p = NS for both). There were no major bleeding events, and the mortality rate with angioplasty (6%) and streptokinase (2%) did not differ (p = NS). CONCLUSIONS: These results suggest that intravenous thrombolytic therapy might be preferred over coronary angioplasty for most patients because of the often shorter time to treatment.