Survival and cardiac event rates in the first year after emergency coronary angioplasty for acute myocardial infarction

Two-year outcome after angiographically documented myocardial reperfusion for acute coronary occlusion. Thrombolysis and Angioplasty Study Group

Reperfusion therapy has been clearly shown to decrease the early mortality after acute myocardial infarction, but the impact of this therapy on long-term survival has been less extensively evaluated. This study reports the extended follow-up of a large cohort of 810 patients treated with intravenous thrombolytic therapy combined, when considered necessary to maintain or augment infarct vessel patency, with mechanical reperfusion therapies. Each patient underwent coronary angiography within 2 hours of the initiation of the thrombolytic infusion. Coronary angioplasty was performed in 62% of the patients before hospital discharge and 21% underwent coronary artery bypass graft surgery. Follow-up was obtained in 96% to a mean of 18.8 months (range, 1.5 to 48 months). All-cause mortality over this period was 3.3%; 2.1% died from cardiac causes. Nonfatal reinfarction occurred in 5.1%. Although the low event rate limits the validity of statistical comparisons, the patients who survived the follow-up period tended to be younger (56 +/- 10 vs 65 +/- 7 years), to have better predischarge left ventricular function (left ventricular ejection fraction, 52 +/- 11 vs 46 +/- 13%) and to have a lower prevalence of multivessel coronary artery disease (45 vs 67%). This excellent long-term survival may, in part, reflect the exclusion of high-risk patients from enrollment in the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) studies. It may also be attributable, however, to the frequent use of combined thrombolysis and mechanical revascularization in this population.

Multivessel coronary angioplasty early after acute myocardial infarction

Coronary angioplasty has been applied in patients with recent myocardial infarction, but results of angioplasty of multiple vessels early after myocardial infarction in patients with severe multivessel disease have not been reported. Coronary angioplasty of multiple vessels was performed in 105 patients 0 to 15 days (mean 5 +/- 4) after recent myocardial infarction. There were 77 men (73%) and 28 women (27%), with a mean age of 57 years. All patients had severe multivessel disease, 68% with two vessel and 32% with three vessel disease. Twenty-eight patients (27%) had successful thrombolysis before angioplasty and 70 (67%) had postinfarction angina. Mean left ventricular ejection fraction was 58 +/- 10% and was less than 45% in 13 patients (12%). Angioplasty was attempted in 319 lesions (mean 3 lesions per patient, range 2 to 9) and 252 vessels (mean 2.4 vessels per patient, range 2 to 4), with success in 302 lesions (95%) and 237 vessels (94%); angioplasty was done in two stages in 59 patients (56%). Clinical success was achieved in 102 patients (97%). Complications included myocardial infarction in six patients (5.7%) (one Q wave, five non-Q wave), urgent bypass surgery in two (1.9%) and death in one (0.9%); overall, seven patients (7%) had a major complication. All patients had a follow-up duration greater than 1 year (mean 31 months, range 12 to 73). Clinical recurrence developed in 24 patients (23%), of whom 21 had repeat angioplasty, 1 had bypass surgery and 2 were managed medically. Ten patients (9.8%) had a late infarction and 5 (4.9%) died of cardiac death during the follow-up period.(ABSTRACT TRUNCATED AT 250 WORDS)

Update on mechanical intervention in acute myocardial infarction

The role of pharmacologic interventions in acute myocardial infarction (i.e., a combination of intravenous nitroglycerin, intravenous beta-blocker, oral aspirin, and intravenous thrombolysis), has become more standardized, whereas the role of mechanical intervention remains to be defined. Mechanical intervention includes percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting. The number of carefully controlled, randomized trials is limited, particularly with surgery. Nevertheless, in optimal circumstances, when performed within the first few hours of myocardial infarction, surgery can be beneficial in reducing mortality, especially with anterior location of infarct. Surgery may not prevent reinfarction. However, the results of nonrandomized surgical trials done 10 years ago are difficult to compare with modern-day treatment of myocardial infarction with the availability of new agents and PTCA. Angioplasty can be performed safely in the acute phase of myocardial infarction but may not be the ideal choice for all patients. The results may be more optimal if performed when the patient is stable. Clinical factors associated with favorable and unfavorable outcomes have been identified. Mortality is not significantly affected by early versus late PTCA. Certain selected patients benefit from PTCA, particularly those in cardiogenic shock, in whom PTCA has made a dramatic improvement in outcome. To achieve maximal benefit, intervention should be performed early, within the first hours of symptoms. Further well-designed studies may help clarify the role mechanical techniques will play in future combinations of interventional therapy.

Brachial approach to emergency cardiac catheterization during thrombolytic therapy for acute myocardial infarction. TAMI Study Group

The use of the brachial approach to acute coronary intervention has not been previously studied. In the course of the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) trials, we used the transbrachial approach to cardiac catheterization with or without angioplasty in 202 of 704 (28.6%) patients. The baseline characteristics of age, sex, risk factors, medical history, time from symptom onset to therapy, and left ventricular function were similar for the 2 different approaches. Time from therapy to coronary angiography was not delayed by the brachial approach compared with the femoral approach: 97.1 +/- 26 min vs. 99.9 +/- 133.8 min, respectively. Chemical patency was established in 78 vs. 73% of patients and technical success with acute PTCA with the brachial approach was 89% vs. 78% with the femoral approach. Clinical outcomes were quite similar with respect to death (6 vs. 6%), reocclusion (10 vs. 14%), and emergency coronary bypass surgery (5 vs. 6%). Baseline hematocrit was 43.9 +/- 4.4 and 43.5 +/- 4.8, respectively with a nadir of 32.9 +/- 5.6 vs. 33.0 +/- 5.4. The need for vascular repair occurred in 1% vs. 3% of patients and retroperitoneal hemorrhage was documented in 1% vs. 1% of patients. This study indicates that in the hands of experienced operators the transbrachial approach to acute coronary intervention in the acute phase of treatment with thrombolytic therapy can be used with equal risks and efficacy as the femoral approach.

PTCA following myocardial infarction: use of bailout fibrinolysis to improve results

The results of percutaneous transluminal coronary angioplasty (PTCA) in 307 lesions in 235 patients within 60 days of myocardial infarction (MI) were compared with the PTCA results in 591 lesions in 489 patients without recent MI, and the effect of fibrinolysis to treat recurring occlusive clot during angioplasty was studied. In 210 lesions in patients with MI who did not receive fibrinolysis during the MI (group A), 58 lesions were categorized as primary failures; bailout fibrinolysis brought the final failure incidence to 42 lesions (20%). In 97 lesions in patients with MI who received fibrinolysis during the acute MI (group B), 22 lesions were categorized as primary failures; bailout fibrinolysis resulted in final failures of 16 lesions (16.5%). In 591 lesions in patients without a recent MI (group C), there were 85 primary failures and 81 final failures after bailout fibrinolysis. Analysis of the PTCA results in each group with respect to whether the lesions were totally or partially occluded showed that more of the lesions attempted in the groups with MI (groups A and B) were totally occluded (TO) and that with use of bailout fibrinolysis the success rate of PTCA in TO lesions was the same in all groups. Similarly, with use of fibinolytic bailout during PTCA the success rate in partially occlusive lesions was not different between the groups. We conclude that bailout thrombolysis during PTCA is usually effective, especially in those who have recently had an MI, and that with availability of bailout fibrinolysis, PTCA in those with recent MI is not any less sucessful than in those without recent MI.(ABSTRACT TRUNCATED AT 250 WORDS)

Thrombolytic therapy for acute myocardial infarction: evaluation of a selective approach to invasive diagnosis and therapy in a community hospital

To investigate the effectiveness of selective catheterization and revascularization after thrombolytic therapy for myocardial infarction, we studied the early and late clinical course of 100 consecutive patients treated with streptokinase and an intensive medical regimen. Catheterization was performed because of recurrent angina or evidence for reperfusion and myocardial salvage. Fifty-six patients were catheterized, and 37 underwent revascularization. Hospital mortality was 8%. Among the 92 hospital survivors, after 1 year follow-up there was no significant difference between the revascularized and nonrevascularized groups in total survival (97% and 100%, respectively) or in infarct-free survival (97% and 95%, respectively). During total follow-up of 34 (+/- 13) months, late clinical events (death, reinfarction, late revascularization, and severe angina) occurred in 16% of 37 revascularized patients and in 27% of 55 patients not revascularized (p = 0.31). Cumulative hospital and late survival for the entire group was 91% at 1 year and 86% at final evaluation. Excellent long-term survival and a low incidence of recurrent infarction may be achieved after thrombolytic therapy, using selective catheterization and revascularization based on widely available clinical estimates of further ischemic risk.

Value of immediate angioplasty after intravenous streptokinase in acute myocardial infarction

To improve reperfusion, immediate percutaneous transluminal coronary angioplasty (PTCA) was considered after intravenous streptokinase (0.75 to 1.5 million U) was administered to 98 patients with acute myocardial infarction less than 4 hours after the onset of chest pain. Thirty-four culprit arteries were occluded (group A); 42 arteries were patent with residual stenosis of more than 70% (group B). Twenty-two patients had residual stenosis of less than 70% (group C); eight of these had severe disease of the remaining vessels. Group C patients were either treated conservatively or underwent bypass surgery. Immediate PTCA was attempted in 74 patients (32 in group A, 42 in group B) and was successful in 68 (92%). Emergency bypass surgery for acute occlusion after PTCA was required in two patients. Follow-up averaged 23 months (range, 16 to 47 months). Asymptomatic occlusion recurred in three patients. Restenosis occurred in five patients: four had early restenosis (one in group A, three in group B) and one had late restenosis (group B). These arteries were successfully redilated. Late reinfarction occurred in two patients. They were treated with intravenous urokinase and repeat PTCA. Elective bypass surgery was performed in three patients because of recurrent angina. They had severe three-vessel disease as revealed by control angiography. The mortality rate was 2.7% (two patients; one in group B had early reinfarction, and one patient in group A died suddenly after 17 months). Eighty-five percent of patients treated with PTCA alone remain free of symptoms. This approach has a high success rate and low morbidity and mortality rates. Long-term results are superior to thrombolysis alone.

Reperfusion in acute myocardial infarction

During the past decade, the general acceptance of the primary role of thrombosis in acute myocardial infarction (AMI) has led to intense interest in the potential efficacy of reperfusion therapy, particularly thrombolytic therapy, in AMI. Accumulating evidence indicates that systemic thrombolytic therapy administered early after the onset of symptoms of AMI can restore infarct-related artery patency, salvage myocardium, and reduce mortality. Recommendations about the proper use of thrombolytic therapy, contraindications, and concomitant therapies (such as aspirin, heparin, nitrates, beta-adrenergic blocking agents, and calcium channel blockers) are reviewed. Although percutaneous transluminal coronary angioplasty (PTCA) is useful for subsets of patients with AMI (for example, patients with anterior infarctions with persistent occlusion of the infarct-related artery after thrombolytic therapy and those with cardiogenic shock), a conservative strategy, including angiography and PTCA only for postinfarction ischemia, is indicated for most patients with AMI in whom initial thrombolytic therapy is apparently successful. The use of PTCA after failed thrombolysis or as direct therapy for AMI seems promising, although further comparisons of PTCA and intravenous thrombolytic therapy are needed. Ongoing studies should help further define the risk-to-benefit ratio of various reperfusion strategies in different subsets of patients, define time limitations for reperfusion therapy, and provide data on therapeutic modalities that will limit reperfusion injury and therefore enhance salvage of myocardium.

One-year outcome after therapy with tissue plasminogen activator: report from the Thrombolysis and Angioplasty in Myocardial Infarction trial

To evaluate the long-term effects of reperfusion with tissue plasminogen activator (t-PA) and an aggressive strategy of revascularization with angioplasty and coronary artery bypass grafting, we obtained 1-year follow-up results from 386 consecutive patients enrolled in the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI I) trial. All patients were treated with 100 to 150 mg of t-PA intravenously over 6 to 8 hours, and coronary angiography was performed within 90 minutes of initiation of therapy. In 197 patients with suitable anatomic characteristics, angioplasty was either performed immediately or was deferred for 7 to 10 days on a randomized basis. The remainder of the patients were treated as considered clinically appropriate. The in-hospital mortality rate was 7%, and only 1.9% of patients died in the first year after discharge from the hospital; three patients died of cardiac events and four died of noncardiac causes. Ninety-four percent of patients discharged alive from the hospital remained alive and had no myocardial infarctions during the first 12 posthospital months. Revascularization procedures after discharge from the hospital included angioplasty in 8% of patients and coronary artery bypass grafting in 5%. The high survival rates were evident in high-risk groups defined by age, ejection fraction, and extent of coronary artery disease. At 1-year follow-up 64% of patients less than 65 years of age were employed and only 10% reported that they were disabled; 94% of patients were in Canadian Heart Association class I or II. These low rates of follow-up events suggest a change in the "natural history" of the first year after acute myocardial infarction.

The Thrombolysis in Myocardial Infarction (TIMI) Trial phase II: additional information and perspectives

Given the many thrombolytic agents and the number of ways in which they can be combined with mechanical revascularization, the treatment of acute myocardial infarction has been the subject of active study and lively debate, which are likely to continue for some time. Several studies, including TIMI IIA (2,3,10,22), have suggested that immediate catheterization and angioplasty offer no clinical benefit and have a greater complication rate than a more delayed invasive strategy, but TIMI II (1) and SWIFT (16) trials have suggested that an even more conservative strategy of reserving catheterization and coronary angioplasty after thrombolytic therapy for patients with recurrent spontaneous or exercise-induced ischemia may be the most desirable approach for the majority of patients similar to those entered into these trials.

Reperfusion therapy in acute myocardial infarction: present status and controversy

Coronary thrombolysis revolutionized the treatment of acute myocardial infarction. Most of the experience was obtained with intravenous use of streptokinase and tissue-type plasminogen activator, the latter being superior to streptokinase in regard to coronary recanalization. Numerous other promising thrombolytic agents are being investigated. Both streptokinase and tissue-type plasminogen activator decreased mortality in large trials; comparison studies in terms of efficacy are presently being performed (GISSI 2). Aspirin is an important adjunct to thrombolytic therapy; it decreased mortality by itself (ISIS 2). Heparin is conventionally used together with thrombolysis. Its efficacy is under study (GISSI 2). Intracranial hemorrhage is the most devastating complication of thrombolysis. With the present dosage regimens, the incidence is approximately 0.5%. Percutaneous transluminal coronary angioplasty in conjunction with thrombolysis accomplished frequent and persistent recanalization of the infarct artery with low mortality, including high risk patients. The TIMI IIB study demonstrated that the results of a "conservative strategy" with aggressive management of recurrent ischemic events were comparable to those of an "invasive strategy." Subgroup analysis should, however, be awaited. High risk patients with low ejection fraction or with shock benefit by early mechanical coronary recanalization. The role of thrombolysis in the "late" stage of transmural myocardial infarction or in the acute ischemic syndrome (unstable angina/non-Q-wave myocardial infarction) is unclear and presently under investigation.

Direct coronary angioplasty in acute myocardial infarction: outcome in patients with single vessel disease

Percutaneous transluminal coronary angioplasty was performed as primary therapy in 215 consecutive patients (aged 56 +/- 11 years, 75% male) with acute myocardial infarction and single vessel coronary artery disease. Wide patency of the infarct-related artery was restored in 212 patients (99%). Complications consisted of one urgent coronary bypass operation (0.5%); there were no procedural deaths. A recurrent ischemic event before discharge occurred in eight patients (4%). The in-hospital mortality rate was 1%; five of six patients presenting with cardiogenic shock were alive at discharge. In 126 patients in whom predischarge angiography was performed, the ejection fraction improved from 55 +/- 12% to 61 +/- 12% (p less than 0.005) and increased by greater than or equal to 5% units in 66 patients (52%). Regional wall motion improved in 60 patients (48%). By multivariate analysis, a depressed initial ejection fraction, a limited increase in serum creatine kinase, young age and sustained patency of the infarct-related artery were found to be independent predictors of improvement in left ventricular function. Follow-up data were available in 214 patients (99.5%) at a mean interval of 35 months. The actuarial 3 year cardiac survival rate was 92%. By multivariate analysis, only the baseline ejection fraction correlated with long-term cardiac survival. Nine patients (4%) sustained a late nonfatal myocardial infarction, and 11 patients (5%) underwent subsequent coronary bypass surgery. At late follow-up study, 149 (77%) of 194 patients alive were free of angina. In summary, in patients with acute myocardial infarction and single vessel disease, coronary angioplasty without prior thrombolytic therapy can be performed with a high success rate and few procedural complications. After direct angioplasty, regional wall motion and global ejection fraction improve in 50% of patients, especially in those with depressed initial left ventricular function. This approach results in an excellent early and late event-free survival.

Tissue plasminogen activator followed by percutaneous transluminal coronary angioplasty: one-year TIMI phase II pilot results. TIMI Investigators

The TIMI phase II pilot study enrolled 288 patients with acute myocardial infarction who were treated with recombinant tissue plasminogen activator (rt-PA) within 4 hours of symptom onset and who were assigned to coronary angioplasty of the infarct-related vessel 18 to 48 hours after rt-PA treatment. The patients were followed to ascertain (1) vital status; (2) whether they suffered a recurrent myocardial infarction; (3) whether they received coronary angioplasty or bypass grafting; and (4) whether they were rehospitalized for a cardiac event. Risk factors for these events or combination of these events were identified and reported. The estimated 6-week, 6-month, and 1-year cumulative event rate of death or myocardial infarction was 9.1 +/- 1.7%, 12.9 +/- 2.0%, and 13.6 +/- 2.0%, respectively. With the exception of repeat hospital admissions, most of the above cardiac events occurred early during the patients' follow-up course. Cox proportional hazard analyses revealed that continuing chest pain after rt-PA administration, history of congestive heart failure, low systolic blood pressure at the time of initial evaluation, and history of hypertension increased the risk of death or recurrent myocardial infarction, while a history of chest discomfort at baseline evaluation and older age was predictive of future hospitalization or a revascularization procedure.

Early and late results of coronary angioplasty without antecedent thrombolytic therapy for acute myocardial infarction

Direct coronary angioplasty without antecedent thrombolytic therapy was performed in 500 consecutive patients with acute myocardial infarction. Anterior and inferior infarctions were noted in 217 and 283 patients, respectively. Two hundred fifteen patients (43%) had 1-vessel disease, 85 patients (17%) were greater than 70 years of age and 39 (8%) presented in cardiogenic shock. Successful angioplasty of the infarct vessel was achieved in 94% of patients. The overall in-hospital mortality was 7.2%. Cardiogenic shock, 3-vessel disease and failed angioplasty were the 3 strongest multivariate correlates of early mortality. Reocclusion of the infarct-vessel was noted in 47 (15%) of the 307 patients with angiographic follow-up before hospital discharge. Significant bleeding complications occurred in only 3% of patients; stroke or myocardial rupture was not seen. The global ejection fraction increased from 53% on the preangioplasty ventriculograms to 59% at 1 week (p less than 0.001). Significant regional wall motion improvement in the infarct segments was noted in 53% of patients. Global ejection fraction improved most dramatically in patients presenting with baseline ejection fractions less than or equal to 45% (increasing from 36 to 50%). The 1- and 5-year survival rates after hospital discharge were 95 and 84%, respectively. The 1-year reinfarction rate was 3%. Thus, direct coronary angioplasty was highly effective in reestablishing infarct-vessel patency and salvaging ischemic myocardium, resulting in low in-hospital and long-term mortality.

Long-term follow-up of patients treated with coronary angioplasty for acute myocardial infarction

Long-term follow-up data for patients treated with coronary angioplasty (PTCA) for acute myocardial infarction are limited. Therefore the long-term outcome of 336 consecutive patients treated with PTCA at a median of 4.5 hours (range 0.5 to 48 hours) from symptom onset was evaluated. The in-hospital mortality was 11.1% (37 patients). Follow-up is complete for 293 of 299 (98%) hospital survivors at a median of 24 months. Of patients discharged, the mean age was 55 +/- 11 years, 49% received intravenous thrombolytic therapy, 53% had multivessel coronary artery disease, and the mean ejection fraction was 48 +/- 10%. Post-discharge survival was 96.1% at 1 year and 93.6% at 2 years by life table analysis. Post-discharge survival was independently predicted by no prior myocardial infarction (96.9% versus 87.3% 2-year survival, p less than 0.001 by log rank analysis) and infarct artery patency at hospital discharge (which had its major impact on survival early after hospital discharge: [97.4% versus 93.4% 1-year survival but 94.2% versus 93.4% 2-year survival; overall p = 0.02]). For patients with analyzable ventriculograms at hospital discharge, ejection fraction greater than or equal to 40% was also a significant independent predictor of survival (98.1% versus 85.8% 2-year survival, p = 0.01). For patients with a successful PTCA, time from symptom onset to catheterization and angioplasty less than or equal to 4 hours versus greater than 4 hours was also an independent predictor of outcome (97.1% versus 91.4% 2-year survival; p = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)

When should angiography follow myocardial infarction?

Both emergency and elective angiography are discussed, with emphasis on their association with the closely linked interventions intravenous thrombolysis and percutaneous transluminal angioplasty.

Comparison of invasive and conservative strategies after treatment with intravenous tissue plasminogen activator in acute myocardial infarction. Results of the thrombolysis in myocardial infarction (TIMI) phase II trial

We treated 3262 patients with intravenous recombinant tissue plasminogen activator (rt-PA) within four hours of the onset of chest pain thought to be caused by myocardial infarction. Of these patients, 1636 were then randomly assigned to treatment according to an invasive strategy consisting of coronary arteriography 18 to 48 hours after the administration of rt-PA, followed by prophylactic percutaneous transluminal coronary angioplasty (PTCA) if arteriography demonstrated suitable anatomy; 1626 patients were randomly assigned to treatment according to a conservative strategy, as part of which arteriography and PTCA were to be performed only in patients with spontaneous or exercise-induced ischemia. In the group assigned to the invasive strategy, PTCA was attempted in 928 of the 1636 patients (56.7 percent); the procedure was anatomically successful in 93.3 percent. In the group assigned to the conservative strategy, 216 patients (13.3 percent) underwent clinically indicated PTCA within 14 days of the onset of symptoms. Reinfarction or death within 42 days, the primary end point, occurred in 10.9 percent of the group assigned to the invasive strategy and in 9.7 percent of those assigned to the conservative strategy (P not significant). There were no significant differences between the two groups in the ejection fraction at rest or during exercise, either at hospital discharge or six weeks after randomization. Eleven of 582 patients (1.9 percent) who received 150 mg of rt-PA and 15 of 2952 patients (0.5 percent) who received 100 mg of rt-PA had intracranial hemorrhage. A subgroup of 1390 patients who were eligible for short-term intravenous beta-blockade were randomly assigned to receive 15 mg of intravenous metoprolol immediately, followed by oral metoprolol, or oral metoprolol begun on day 6. The ejection fraction and the incidence of death in the two groups were similar during the hospital period. Total mortality within the first 6 days and at 42 days was also similar. However, in the group that received intravenous metoprolol, 16 patients had nonfatal reinfarctions and 107 patients had recurrent ischemic episodes by six days after entry into the study, as compared with 31 and 147 patients, respectively, among those randomly assigned to deferred oral beta-blockade (P = 0.02 and P = 0.005, respectively); the latter comparison was considered statistically significant according to the study criteria.(ABSTRACT TRUNCATED AT 400 WORDS)

Emergency percutaneous transluminal coronary angioplasty during acute myocardial infarction for patients more than 70 years of age

Thirty-five patients greater than 70 years of age with acute myocardial infarction (AMI) were treated with emergency percutaneous transluminal coronary angioplasty (PTCA). Seventeen (49%) patients received previous thrombolytic therapy: streptokinase (10 patients), tissue plasminogen activator (6) and combined tissue plasminogen activator and urokinase (1). Infarct-related artery patency was achieved in 26 patients (74%) after PTCA. Total in-hospital mortality was 34%. Univariate analysis showed a higher in-hospital mortality in patients with an occluded vessel after PTCA (78%) than in those patients with a patient infarct-related artery (19%) (p = 0.003). Symptomatic coronary reocclusion occurred in 3 patients (15%) during the hospital stay. Compared with emergency PTCA in 200 consecutively treated patients less than 70 years of age, the in-hospital mortality was increased (34 vs 6%, p less than 0.001), and the primary success rate was reduced (66 vs 90%, p less than 0.001). At a mean follow-up of 28 months, there has been a 13% out-of-hospital mortality rate in the elderly patients (3 patients died). Of the 20 surviving patients, 14 are asymptomatic and 6 have class II angina. In conclusion, emergency PTCA for AMI in elderly patients is associated with a decreased success rate and a higher mortality rate. However, the in-hospital mortality rate is not dissimilar to that in elderly AMI patients treated with conventional therapy or thrombolytic therapy alone, and the postdischarge mortality rates are low.

Administration of thrombolytic therapy in the community hospital: established principles and unresolved issues

In patients with acute myocardial infarction presenting to community hospitals, thrombolytic therapy should be initiated as rapidly as possible under the supervision of a physician. Paramedic or nurse-initiated pre-hospital therapy is currently investigational. Each hospital must have a detailed evaluation and treatment protocol for acute myocardial infarction that specifies the timetable for patient evaluation, who should or should not receive thrombolytic therapy and the proper dose and mode of administration of the agent or agents to be used. Monitoring after the administration of thrombolytic therapy should focus on arrhythmias, hemodynamic problems, recurrent ischemia and bleeding. The role of early cardiac catheterization to detect patients who have unsuccessful thrombolysis or who require mechanical revascularization procedures is under active investigation. The design of the Thrombolysis and Angioplasty in Acute Myocardial Infarction (TAMI) 5 study, which addresses the role of acute interventional catheterization in the treatment of patients with acute myocardial infarction, is described.

Characteristics and outcome of patients in whom reperfusion with intravenous tissue-type plasminogen activator fails: results of the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) I trial

To examine the outcome of patients with persistent coronary artery occlusion despite treatment with intravenous tissue-type plasminogen activator (t-PA), the clinical course of 96 patients with persistent occlusion after 90 min of therapy was evaluated. All patients underwent cardiac catheterization 90 min after initiation of intravenous t-PA. Immediate coronary angioplasty (PTCA) was attempted when the infarct-related artery failed to reperfuse unless the vessel was technically unsuitable or the infarct was thought to be small. No baseline differences could be found between these 96 patients and 288 patients who achieved perfusion with the same protocol. Although patients with and without successful perfusion after t-PA had similar clinical courses before cardiac catheterization, those without perfusion had more complications (ventricular fibrillation, severe bradycardia, hypotension) during catheterization. PTCA achieved reperfusion with less than 50% residual stenosis in 73% of the 86 patients in whom it was attempted, while 16% were left with a high-grade (greater than 50%) residual stenosis and PTCA failed in 11%. Mortality was highest in the nine patients with complete PTCA failure (44%), compared with a 6% mortality in the 63 patients with an insignificant residual stenosis after PTCA and a 14% mortality in the 14 patients with reperfusion, but a greater than 50% residual stenosis after PTCA. In 10 patients with small infarcts (six), unsuitable anatomy (two), or "spontaneous" drug induced (but later) opening before contemplated PTCA (two), PTCA was not attempted and no mortality occurred. The in-hospital reocclusion rate after successful PTCA was 29%, despite the use of heparin and antiplatelet agents.(ABSTRACT TRUNCATED AT 250 WORDS)