Angioplasty For Myocardial Infarction Research Articles

Primary angioplasty in myocardial infarction.

Primary angioplasty in myocardial infarction.

778-6 Timing, Mode and Predictors of Death After Direct Angioplasty for Acute Myocardial Infarction

The timing and mechanisms of early (30 day) mortality in 330 consecutive patients (pts) treated with direct angioplasty less than 12 hours after onset of myocardial infarction (MI) without antecedent thrombolysis were studied. There were 38 deaths (11,5% of pts). with a majority being due to cardiogenic shock (76%). Other causes included acute closure (11%). death after emergency bypass surgery (5%), ventricular arrhythmias (5%), and respiratory failure (3%1. Therefore 37 of 38 deaths (97%) were cardiac. No deaths from stroke or cardiac rupture were seen, in contrast to trials of thrombolytic agents, Most deaths were seen early, with 47% occurring within 1 day, 35% from days 2–7, and 18% from days 8–30, Deaths from cardiogenic shock was the most common cause of death throughout this period: 83% of deaths in days 0–3, 88% of deaths in days 4–6, and 43% of deaths in days 8–30. The pts who died were significantly older (69 ± 11 vs. 61 ± 11 years, p < 0,0001), had more frequent direct angioplasty failure 124% vs 7%, P < 0.05), reduced ejection fraction (31 ± 17% vs 44 ± 14%, P < 0.0001), more multivessel disease (74% vs 54%, p < 0.05), and more anterior infarcts (74% vs 42%, p < 0.0005) than survivors, Gender, prior MI, and prior bypass surgery did not effect mortality. Cardiogenic shock is the most common cause of early death after direct angioplasty for MI. Pts with one or more risk factors for early death may benefit from additional myocardial salvage or revascularization efforts in the early post-infarct period. Causes of death after direct angioplasty appear to be different than those described after lytic therapy for MI. Specifically, myocardial rupture and intracranial hemorrhage were not causes of death in this study population.

Predictors of in-hospital and 6-month outcome after acute myocardial infarction in the reperfusion era: The primary angioplasty in myocardial infarction (PAMI) trial

Objectives. This study examined the predictors of in-hospital and 6-month outcome after different reperfusion strategies in acute myocardial infarction.Background. Thrombolytic therapy and primary angioplasty are both widely applied as reperfusion modalities in patients with myocardial infarction. Although it is accepted that restoration of early patency of the infarct-related artery can reduce mortality and salvage myocardium, the optimal reperfusion strategy remains controversial, and the predictors of outcome in the reperfusion era have been incompletely characterized.Methods. At 12 centers, 395 patients presenting within 12 h of onset of acute transmural myocardial infarction were prospectively randomized to receive tissue-type plasminogen activator (t-PA) or undergo primary angioplasty without antecedent thrombolysis. Sixteen clinical variables were examined with univariate and multiple logistic regression analysis to identify the predictors of clinical outcome.Results. By univariate analysis, in-hospital mortality was increased in the elderly, women, patients with diabetes and in patients treated with t-PA as opposed to angioplasty. Only advanced age and treatment by t-PA versus angioplasty independently correlated with increased in-hospital mortality (6.5% vs. 2.6%, respectively, p = 0.039 by multiple logistic regression analysis). Similarly, the only variables independently related to in-hospital death or nonfatal reinfarction were advanced age and treatment by t-PA versus angioplasty (12.0% vs. 5.1%, p = 0.02). The reduction in in-hospital death or reinfarction with angioplasty versus t-PA was particularly marked in patients ≥65 years of age (8.6% vs. 20.0%, p = 0.048). Furthermore, primary management with angioplasty versus t-PA was the most powerful multivariate correlate of freedom from recurrent ischemic events (10.3% vs. 28.0%, p = 0.0001). The independent beneficial effect of angioplasty on freedom from death or reinfarction was maintained at 6-month follow-up (8.2% vs. 17.0%, p = 0.02).Conclusions. In the reperfusion era, the two most powerful determinants of freedom from death, reinfarction and recurrent ischemia after myocardial infarction are young age and treatment by primary angioplasty.

Clinical importance of thrombocytopenia occurring in the hospital phase after administration of thrombolytic therapy for acute myocardial infarction

Objectives. The purpose of this study was to examine the incidence and clinical implications of thrombocytopenia that occurs in hospital after administration of thrombolytic therapy for acute myocardial infarction.Background. The use of thrombolytic therapy in patients with acute myocardial infarction has improved mortality rates, but hemorrhage remains a major complication. Because thrombocytopenia may be associated with hemorrhage after thrombolytic therapy, we examined the incidence and clinical implications of thrombocytopenia after administration of thrombolytic therapy for acute myocardial infarction.Methods. The patient population comprised 1,001 patients enrolled in Phases 2,3 and 5 of the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) trial and the urokinase trial. Patients received recombinant tissue-type plasminogen activator, urokinase or combination therapy in various dosing schemes. All patients received heparin, aspirin and a calcium-channel blocking agent. Thrombocytopenia occurring anytime after thrombolytic therapy was defined as a nadir platelet count either <100,000/μl or < 1/2 baseline. Blood loss was quantified by a bleeding index. Multiple logistic regression was used to evaluate the independent contribution of thrombocytopenia in a model predicting inhospital mortality.Results. Thrombocytopenia occurred in 16.4% of patients, with no difference among the thrombolytic regimens. Patients with thrombocytopenia had a lower median acute ejection fraction and a higher likelihood of three-vessel coronary artery disease than patients without thrombocytopenia. Patients with thrombocytopenia had more hemorrhage, a higher in-hospital mortality rate and a more complicated hospital course than patients without thrombocytopenia, even after consideration of other important variables, including age, acute ejection fraction, number of diseased vessels, bypass surgery and use of intraaortic balloon counterpulsation.Conclusions. Thrombocytopenia after thrombolytic therapy is a common event and is associated with excess hemorrhage and mortality. Platelet counts should be monitored daily after administration of thrombolytic therapy because the appearance of thrombocytopenia identifies a subset of patients at increased risk for hemorrhage and death.

Thrombolytic therapy for women with myocardial infarction: Is there a gender gap?

Objective. The goal of this study was to investigate whether femele gender portends an adverse prognosis independent of the severity of the underlying disease after acute myocardial infarction treated by thrombolysis. A total of 348 women were compared with 1,271 men enrolled in the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) trials.Background. The reasons for gender differences in the management and prognosis of acute coronary artery syndromes remain poorly defined. The extent to which gender itself explains observed differences in outcome and use of diagnostic procedures remains unclear because confounding factors have not been specified.Methods. Patients <76 years of age presenting within 6 h of onset of ischemic symptoms with electrocardiographic ST segment elevation and without contraindications to thrombolysis, previous infarction in the same distribution or cardiogenic shock were prospectively enrolled in Phases 1 to 3, 5 and 7 of the TAMI trials. All patients received recombinant tissue-type plasminogen activator, urokinase or a combination of both agents. Protocolmandated cardiac catheterization was performed during the hospital period, Rescue coronary angioplasty was carried out for reperfusion failure at angiography 90 min after initiation of thrombolytic therapy. Coronary artery bypass grafting or coronary angioplasty was performed for clinical indications.Results. Women were older than men (61.0 ± 9.7 vs. 55.8 ± 10.1 years, mean ± SD) and had a higher incidence of many risk factors for adverse outcome after myocardial Infarction, There were no differences in baseline hemodynamic variables or time to thrombolytic treatment. Rates of acute and predischarge infarctrelated artery patency and global and regionl left ventricular function were similar in the two groups. Rates of in-hospital coronary angioplasty (52.6% and 54.1%) and bypass graft surgery (10.4% and 22.0%) were comprable in women and men, respectively, Women had higher unadjusted rates of mortality (9.2% vs. 5.4%, p = 0.014), reinfarction (6.4% vs. 2.6%, p = 0.005) and hemorrhagic stroke (2.0% vs. 0.55%, p = 0.017) than did men during the hospital period. When adjusted for clinical and angiographic variables, differences in mortality and hemorrhagic stroke did not reach statistical significance, and the risk of reinfarction was only marginally associated with gender.Conclusions. In selected patients undergoing thrombolytic therapy and cardiac catheterization for acute myocardial infarction, adjusted mortality rates and utilization of postlysis revascularization are similar in women and men. However, women may be at increased risk for reinfarction.

Minimizing the risk of inappropriately administering thrombolytic therapy (Thrombolysis and Angioplasty in Myocardial Infarction [TAMI] study group)

Despite the proven benefits of thrombolytic therapy in acute myocardial infarction, concern for its complications, especially in patients misdiagnosed with myocardial infarction, has led to hesitancy in its use. Historical, clinical and electrocardiographic criteria were developed for enrolling patients with suspected acute myocardial infarction into thrombolytic trials by noncardiovascular specialists. The incidence of misdiagnosis of myocardial infarction and the clinical outcomes when these criteria were used were evaluated for 1,387 consecutive patients given thrombolytic therapy. Twenty-five community hospitals and 7 interventional centers were the sites of enrollment. Most patients (63%) were enrolled from community hospitals. Criteria for thrombolytic therapy included: symptoms of acute myocardial infarction <6 hours but >20 minutes, and not relieved by nitroglycerin; and ST-segment elevation ≥1 mm in 2 contiguous leads or ST-segment depression of posterior myocardial infarction. Exclusion criteria reflecting increased risk of bleeding were used. A final diagnosis of myocardial infarction was based on creatinine kinase-MB, electrocardiographic and ventriculographic evaluation. Acute myocardial infarction was misdiagnosed in 20 patients (1.4%; 95% confidence interval 0.8–2.0%). These patients were demographically similar to those with acute myocardial infarction. All misdiagnosed patients survived; no significant adverse events occurred. Thus, in several clinical settings, a simple algorithm with specific criteria was used for diagnosing acute myocardial infarction and administering thrombolytic therapy. The inclusion criteria used in this study led to a low rate of misdiagnosis.

What data support our current thrombolytic management of patients with acute myocardial infarction?

T HE DECADE of the eighties is characterized by major advances in the management of patients with evolving myocardial infarction. Large-scale, placebo-controlled studies have shown that intravenous thrombolytic therapy with streptokinase (SK), anisoylated plasminogen-streptokinase activator complex (APSAC), or the relatively fibrin-specific agent recombinant-tissue type plasminogen activator (rtPA), reduces short-term mortality in selected populations by 18% to 50%.le4 This difference is maintained for at least 15 months.@ The most recently reported trials, Gruppo Italian0 per lo Studio della Streptochinasi nell’ Infarto Miocardio (GISSI)-2 and International Study of Infarct Survival (ISIS)-3, failed to show statistically significant differences in 30 to 35 day mortality when comparing SK, APSAC, and rtPA.‘s8 Skepticism has surrounded these results because of dissent over the adequacy of the heparinization regimen. However, they surprised many who had speculated that treatment with rtPA, which in the Thrombolysis in Myocardial Infarction (TIMI)-I trial appeared to lyse coronary thrombi faster than streptokinase,9 would translate into improved survival rates. The numerous reperfusion, patency, and mortality trials conducted to date have firmly established thrombolysis as the cornerstone therapy for evolving myocardial infarction in eligible patients. They have provided a wealth of information on the pathophysiology of acute coronary occlusion, the thrombus/vessel wall interactions, and the advantages and disadvantages of relative fibrin specificity. They also gave new insights into clinical prognostic factors. The observation that coronary patency may be a better prognostic indicator of shortand longterm outcome than residual left ventricular (LV) function as assessed by ejection fraction,1°-13 led to the formulation of the “open artery” hypothesis. This generated a flurry of clinical research activity, as exemplified by the TIM1 and Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) study groups, focusing on pharmacological and/or mechanical means of reestablishing or maintaining patency of the culprit coronary artery. With thrombolytic therapy for acute myocardial infarction (AMI) now widely accepted, physicians are constantly confronted with the fundamental guideline: “Primum non nocere.” While lytic therapy has reduced in-hospital mortality to 10% or less, compared with 12% to 15% in the prethrombolytic era, intracerebral hemorrhage has made its inroad in the clinical picture, with a reported incidence of 0.5% to 1.5%, depending on the agent used and the aggressiveness of the infusion regimen. As discussed by Top01 elsewhere in this symposium,14 the decision to administer thrombolysis, the choice of the thrombolytic agent, and the choice of any adjunctive mechanical or pharmacological treatment must be based on the expected net clinical benefit to the patient. Large studies

Thrombolysis in postinfarction angina

Postinfarction angina carries a poor prognosis, with a 20–70% incidence of recurrent myocardial infarction (MI) or death within the subsequent 3–6 months. The pathophysiologic mechanisms causing postinfarction angina may include thrombus, complex coronary arterial lesions that form a nidus for thrombus formation, inadequate collateral supply following acute MI, or intimal endothelial dysfunction. The role of thrombus has been established in the pathophysiology of Q-wave MI, and thrombolytic treatment of patients presenting with acute transmural MI has been shown to salvage left ventricular function and to reduce mortality. However, thrombolytic therapy for the acute MI does not reduce the incidence of recurrent ischemia or infarction, as is evident from the 18–26% incidence of recurrent ischemia reported in the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) and Thrombolysis in Myocardial Infarction (TIMI) trials. In the Gruppo Itaiiano per lo Studio della Streptochinasi nell Infarto Miocardico (GISSI) study the incidence of reinfarction was documented as 4% in the streptokinase group, which was actually significantly greater than in the placebo group (2%). In a randomized placebo-controlled study of thrombolysis for postinfarction angina, 29 patients were randomized to placebo (P group, n = 17) or to thrombolytic therapy (T group, n = 12). Patient groups were similar with respect to age, location of MI, ejection fraction, severity of coronary artery disease, and antianginal therapy. Patients underwent coronary angtography 6 ± 1 days postinfarction. Filling defects consistent with intracoronary thrombus was seen in 11 of 12 T group patients and in 11 of 17 P group patients prior to treatment. Lysis occurred in 7 of 11 T patients and 1 of 11P (p < 0.02). Holter-detected silent ischemia was compared pre- and posttherapy. Of patients with pretherapy Holter studies, silent ischemia occurred in 8 of 15 P patients (1.7 ± 0.33 episodes/24 hr, lasting 27.9 ± 12.1 min/24 hr) and in 2 of 9 T patients (0.6 ± 0.4 episodes/24 hr lasting 9.4 ± 3.1 min/24 hr). There was no significant change in the amount of silent ischemia following therapy in either group. Clinical ischemic events occurred in 3 of 12 T patients and in 5 of 17 P patients (no difference between the 2 groups). This study showed that thrombus was commonly seen in patients with postinfarction angina, and thrombolytic therapy could successfully lyse the clot 6 days postinfarction. However, despite achieving successful thrombolysis, in patients who were already receiving an intensive antianginal regimen for postinfarction angina, thrombolytic therapy did not result in an improvement in Holter-detected or clinical ischemia.

Thrombolytic therapy plus an aggressive angiographic strategy were more effective than monotherapy for reducing complications after myocardial infarction

Source Citation Califf RM, Topol EJ, Stack RS, et al. Evaluation of combination thrombolytic therapy and timing of cardiac catheterization in acute myocardial infarction. Results of thrombolysis and angioplasty in myocardial infarction—Phase 5 randomized trial. Circulation. 1991 May;83:1543-56.

Evaluation of combination thrombolytic therapy and timing of cardiac catheterization in acute myocardial infarction. Results of thrombolysis and angioplasty in myocardial infarction--phase 5 randomized trial. TAMI Study Group.

Recent trials of myocardial reperfusion using single-agent thrombolytic therapy and sequential cardiac catheterization have supported a conservative approach to the patient with acute myocardial infarction. To evaluate combination thrombolytic therapy and the role of a previously untested strategy for the aggressive use of cardiac catheterization, we performed a multicenter clinical trial with a 3 x 2 factorial design in which 575 patients were randomly allocated to one of three drug regimens--tissue-type plasminogen activator (t-PA) (n = 191), urokinase (n = 190), or both (n = 194) - and one of two catheterization strategies--immediate catheterization with angioplasty for failed thrombolysis (n = 287) or deferred predischarge catheterization on days 5-10 (n = 288). Patients with contraindications to thrombolytic therapy, cardiogenic shock, or age of more than 75 years were excluded. Global left ventricular ejection fraction was well preserved and almost identical at predischarge catheterization (54%), regardless of the catheterization or thrombolytic strategy used (p = 0.98). Combination thrombolytic therapy was associated with a less complicated clinical course, most clearly documented by a lower rate of reocclusion (2%) compared with urokinase (7%) and t-PA (12%) (p = 0.04) and a lower rate of recurrent ischemia (25%) compared with urokinase (35%) and t-PA (31%). When a composite clinical end point (e.g., death, stroke, reinfarction, reocclusion, heart failure, or recurrent ischemia) was examined, combination thrombolytic therapy was associated with greater freedom from any adverse event (68%) compared with either single agent (urokinase, 55%; t-PA, 60%) (p = 0.04) and with a less complicated clinical course when the composite clinical end points were ranked according to clinical severity (p = 0.024). Early patency rates were greater with combination therapy, although predischarge patency rates after considering interventions to maintain patency were similar among drug regimens. No difference in bleeding complication rates was observed with any thrombolytic regimen. The aggressive catheterization strategy led to an overall early patency rate of 96% and a predischarge patency rate of 94% compared with a 90% predischarge patency in the conservative strategy (p = 0.065). The aggressive strategy improved regional wall motion in the infarct region (-2.16 SDs/chord) compared with deferred catheterization (-2.49 SDs/chord) (p = 0.004). More patients treated with the aggressive strategy were free from adverse outcomes (67% versus 55% in the conservative strategy, p = 0.004), and the clinical course was less complicated when the adverse outcomes were ranked according to severity (p = 0.016). No significant increase in use of blood products resulted from the aggressive strategy.(ABSTRACT TRUNCATED AT 400 WORDS)

Relation between flow grade after thrombolytic therapy and the effect of angioplasty on left ventricular function: A prospective randomized trial

Recent intervention trials during myocardial infarction demonstrated no benefit from emergency angioplasty after thrombolytic therapy when compared with either delayed percutaneous transluminal coronary angioplasty (PTCA) or a conservative strategy. However, it is possible that subgroups of patients may benefit from early intervention with angioplasty. We performed a prospective randomized trial in patients with a patent infarct-related artery after thrombolytic therapy to determine whether initial flow grade is related to infarct-zone function and whether patients with ineffective reperfusion (>90% stenosis or Thrombolysis in Myocardial Infarction [TIMI] flow ≤2) might benefit from immediate PTCA. Thrombolytic therapy was administered to 170 patients at a mean of 2.1 ± 0.5 hours after onset of myocardial infarction. A patent infarct-related artery that was suitable for angioplasty was present in 89 patients who comprised the study group; after randomization, 47 of 50 patients with a patent infarct-related artery had successful emergency PTCA 3.8 ± 1.5 hours after onset of symptoms, and 39 were scheduled for delayed (18 to 48-hour) PTCA. Reocclusion occurred before the scheduled (delayed) procedure in eight patients (20.5%), and was symptomatic in six. Infarct-region function (by the centerline method) measured initially, before discharge, and at 4 months was similar in both groups; improvement was significant (p < 0.001) at discharge when compared with initial values with no further change at 4 months. However, patients with ineffective reperfusion had greater hypokinesia initially (p < 0.05) compared with those with effective reperfusion (≤90% stenosis plus TIMI flow 3). Moreover, independent of the timing of PTCA, improvement was greater before discharge in patients with ineffective reperfusion (p < 0.05) with a trend also evident at 4 months. Importantly, 42 of 51 patients (82%) with a residual lumen <0.4 mm after thrombolysis had some improvement in function at discharge; this compares with a previous study in which patients with a similar degree of stenosis (without PTCA) had no improvement. Moreover, reocclusion occurred before scheduled (delayed) PTCA in 37% of patients with >90% stenosis compared with only 5% in those with ≤90% stenosis (p = 0.02). Thus flow grade is an important determinant of myocardial function in patients with a patent artery after thrombolytic therapy and is predictive both of improvement in wall motion after PTCA and early reocclusion. Data from this and the recently presented Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) 5 study suggest that immediate angiography during myocardial infarction can be used to select patients who may benefit from early intervention.

Primary angioplasty in myocardial infarction: Assessment of improved myocardial perfusion with technetium-99m isonitrile

Technetium-99m-hexakis-2-methoxy-2-isobutyl-isonitrile (technetium-99m isonitrile) is a new radiopharmaceutical compound that reflects myocardial perfusion. Its kinetics, especially its lack of redistribution after intravenous administration, permits the assessment of changes in myocardial perfusion without delay of therapy. Tomographic images at rest were obtained immediately and 6 to 10 days later in 17 consecutive patients undergoing successful primary angioplasty during their first transmural myocardial infarction. Thirteen patients had anterior infarction. The initial (acute) defect size before angioplasty of 48 +/- 17% of the left ventricle decreased significantly (p less than 0.0001) to 29 +/- 19% on the late scans. There was no correlation between the time to therapy and the reduction in defect size. Twelve of the 17 patients, including 7 of the 11 patients treated after 4 h, demonstrated a definite reduction in the initial defect size. Eight patients with angiographically proved persistent coronary occlusion underwent a similar imaging sequence. The initial defect size in this group remained unchanged on the late scans (24 +/- 16% versus 26 +/- 18%, p = NS). Primary angioplasty is an effective approach toward salvaging myocardium; comparison with thrombolytic drug therapy must await the results of controlled clinical trials.

Racial differences in responses to thrombolytic therapy with recombinant tissue-type plasminogen activator. Increased fibrin(ogen)olysis in blacks. The Thrombolysis and Angioplasty in Myocardial Infarction Study Group.

To determine whether there are differences in responses to thrombolytic therapy in certain populations, the data for the Thrombolysis and Angioplasty in Myocardial Infarction (phase 1) study were analyzed for black and white patients. Baseline variables including risk factors and extent of coronary artery disease were similar in the 352 white and 24 black patients. The time from onset of chest pain to recombinant tissue-type plasminogen activator (rt-PA) therapy and rt-PA dosing regimens were the same in the two groups. The patency rate of the infarct-related artery at 90 minutes was 91% for blacks and was 72% for whites (p = 0.051). Blacks displayed significantly lower nadir fibrinogen levels (0.57 +/- 0.62 versus 1.3 +/- 0.76 g/l, p less than 0.0001), greater delta fibrinogen (baseline-nadir) (2.7 +/- 1.1 versus 1.7 +/- 1.1 g/l, p less than 0.0001), and increased peak levels of fibrin(ogen) degradation products (837 +/- 865 versus 245 +/- 475 micrograms/ml, p less than 0.0001). rt-PA antigen levels tended to be higher in blacks than in whites (2.8 +/- 2.2 versus 2.2 +/- 3.2 micrograms/ml [p = 0.10] at the peak and 1.6 +/- 1.3 versus 0.99 +/- 1.4 micrograms/ml [p = 0.06] at the end of the maintenance infusion). Major clinical outcomes including survival until time of hospital discharge (92% black versus 93% white, p = 0.68) were not significantly different. However, despite undergoing fewer angioplasty procedures (25% versus 46.3%, p = 0.047), blacks received more transfusions (58.8% versus 19.5% were administered greater than or equal to 2 units packed erythrocytes, p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Two-year outcome after angiographically documented myocardial reperfusion for acute coronary occlusion

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.

Fate of patients with acute myocardial infarction with patency of the infarct-related vessel achieved with successful thrombolysis versus rescue angioplasty

Patients with failure of infarct-related artery recanalization after thrombolytic therapy have a poor clinical outcome. These patients have been considered for rescue angioplasty 90 min after thrombolytic therapy at the time of emergency catheterization in the course of five Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) trials. The outcome of 776 patients with patent infarct-related vessels after emergency catheterization was analyzed--607 with thrombolysis-mediated patency of the infarct-related vessel and 169 with patency achieved by angioplasty. Baseline characteristics of the thrombolysis and angioplasty patency groups were similar except for a higher acute left ventricular ejection fraction (51.3% versus 48.2%) in the thrombolysis group (p = 0.003). Seven to 10 day left ventricular ejection fraction was higher (52.3% versus 48.1%), infarct zone functional recovery was greater (0.44 versus 0.21 standard deviation/chord, or 18% versus 7%, p = 0.001) and reocclusion was less (11% versus 21%) in the thrombolysis compared with the angioplasty group. Despite these differences, angioplasty patency was associated with the same low in-hospital mortality rate (5.9% versus 4.6%) and long-term mortality rate (3% versus 2%) as thrombolysis patency. Reocclusion adversely affected the mortality rate and ventricular functional recovery. Technical failure of rescue angioplasty was associated with a much higher mortality rate than was technical success (39.1% versus 5.9%). Thrombolysis patency was preferable to angioplasty patency after thrombolytic therapy in acute myocardial infarction, but both were associated with the same low in-hospital and long-term mortality rates, suggesting that rescue angioplasty is beneficial in some patients with failure of infarct-related artery recanalization after thrombolytic therapy.

Stroke and acute Myocardial Infarction in the Thrombolytic era: Clinical correlates and long-term prognosis

Thirteen (1.8%) of 708 patients with acute myocardial infarction treated with recombinant tissue-type plasminogen activator in the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) I, II and III trials developed a stroke. Four strokes were hemorrhagic and nine were nonhemorrhagic. Of five prespecified risk factors for intracranial hemorrhage (age >65 years, history of hypertension, history of prior cerebrovascular disease, aspirin use and acute hypertension), two patients had two risk factors and one patient had one risk factor. However, 80% of patients without intracranial hemorrhage had at least one risk factor and 31% had two risk factors. No patient with a prior stroke or transient ischemic attack (all >6 months previously) had an intracranial hemorrhage.Of three prespecified risk factors for nonhemorrhagic stroke (atrial fibrillation, prior cerebrovascular disease and large anterior wall infarction), only the occurrence of a large anterior myocardial infarction (with ejection fraction <45%) was a predictor (p = 0.0015).The in-hospital death rate was 25% for patients with hemorrhagic stroke versus 11% for patients with a non-hemorrhagic stroke and 6% for those patients without a stroke. Furthermore, the hospital stay was >50% longer in patients who had a stroke than in those who did not.Thus, intracranial hemorrhage remains an unpredictable risk in patients treated with thrombolytic therapy and cerebral infarction is related to anterior myocardial infarction and poor left ventricular function. Both types of stroke are associated with substantial morbidity and mortality.

Brachial approach to emergency cardiac catheterization during thrombolytic therapy for acute Myocardial Infarction

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.

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.

Recurrent ischemia without warning. Analysis of risk factors for in-hospital ischemic events following successful thrombolysis with intravenous tissue plasminogen activator.

Ischemic events after successful thrombolysis have been reported to occur in 18-32% of patients treated for acute myocardial infarction with thrombolytic therapy, and previous studies in which patients received streptokinase suggest that risk of early recurrent ischemia is closely related to the presence of a high-grade residual stenosis. If these events are predictable after intravenous recombinant tissue-plasminogen activator (rt-PA) thrombolytic therapy, then further intervention after its use could be targeted at selected patients. One-hundred ninety-two patients from the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) I and TAMI III trials had successful rt-PA-mediated thrombolysis without immediate coronary angioplasty (PTCA). One-hundred seventy-four of these patients (92%) had prehospital discharge angiography. The mean age was 56 +/- 11 years; 81% were men; the infarct-related artery was the left anterior descending in 76 (39.8%), the left circumflex in 24 (12.6%), and the right coronary artery in 91 (47.6%). Thrombolysis with rt-PA resulted in a residual 73 +/- 13% diameter and 0.95 +/- 0.51 mm stenosis by quantitative coronary arteriography, and Thrombolysis in Myocardial Infarction (TIMI) flow grade 2 in 59.2% and 3 in 40.8% of stenoses as assessed on angiograms obtained 90 minutes after the initiation of rt-PA therapy. Recurrent ischemic events (ischemia requiring emergency percutaneous transluminal coronary angioplasty or urgent bypass surgery, reocclusion of the infarct-related artery, or cardiac death) occurred in 41 patients (21.3%).(ABSTRACT TRUNCATED AT 250 WORDS)

Favorable early and long-term prognosis following coronary bypass surgery therapy for myocardial infarction: Results of a multicenter trial

Coronary bypass surgery was performed before hospital discharge on 82 (21%) of 386 consecutive patients enrolled in the Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) multicenter trial of intravenous tissue plasminogen activator and coronary angioplasty for acute myocardial infarction. Time from infarct symptom onset to coronary bypass surgery was 7.3 ± 1.9 hours for 24 patients operated upon on an emergency basis and 9.3 ± 5.2 days for 58 patients having late in-hospital surgery. There were no operative deaths and five in-hospital deaths in the surgical group, all of which occurred in patients with preoperative cardiogenic shock. Although patients in the surgical group were older (59.7 ± 10.4 years versus 54.9 ± 10.2 years; p = 0.03), had more extensive coronary artery disease (42% three-vessel disease versus 11%; p = 0.001), and had a higher incidence of anterior wall myocardial infarction (48% versus 39%; p = 0.02), in-hospital mortality for the surgical group (6%) was similar to that in 301 patients not undergoing surgery (7%) in this trial. For patients discharged from the hospital, mortality at 1 year was 2.5% in the surgical group and 1.8% in patients not having coronary bypass surgery before hospital discharge. At a 1 year follow-up, there were no significant differences in the frequency of cardiac or noncardiac-related hospitalizations or in event-free survival between surgical and nonsurgical groups. The majority of patients in both groups considered themselves to be in excellent or good condition. Coronary bypass surgery can be performed with low morbidity and mortality rates in close temporal association to acute myocardial infarction. Despite the presence of high-risk clinical descriptors (age, extent of coronary disease, and anterior myocardial infarction) in surgical patients, a similar hospital and 1-year mortality, event-free survival, angina status, and general health status was observed in both groups of patients