Implications for patient triage from survival and left ventricular functional recovery analyses in 500 patients treated with coronary angioplasty for acute myocardial infarction

The in-hospital course of 500 consecutive patients treated with coronary angioplasty for acute myocardial infarction was reviewed in relation to their clinical and angiographic presentation and angioplasty outcome to determine which patients benefit most from successful angioplasty in this setting. Patient age was 56 +/- 11 years (mean +/- SD) and 78% were men; 46% had anterior myocardial infarction, 49% received concomitant intravenous thrombolytic therapy, left ventricular ejection fraction was 47 +/- 11% and median time to angioplasty was 4.7 h (range 1 to 24). Angioplasty was successful in 78% of patients and partially successful in 7% of patients; the overall in-hospital mortality rate was 10.2%. Multivariate analysis found six independent correlates (p less than 0.05) of in-hospital mortality: left ventricular ejection fraction less than or equal to 30%, lack of postangioplasty infarct artery patency, age greater than 65 years, recurrent ischemia after successful angioplasty, emergency bypass surgery and arterial pressure on admission to the catheterization laboratory less than 100 mm Hg. After consideration of these predictors of survival in multivariate analyses, angioplasty success still was independently correlated with improved in-hospital survival for patients with cardiogenic shock (p = 0.002) and anterior myocardial infarction (p = 0.007). A trend toward an independent beneficial effect of successful angioplasty on survival was also noted in patients with inferior wall infarction and precordial ST segment depression (p = 0.063) and for all patients who were hypotensive on admission to the catheterization laboratory, regardless of the infarct site (p = 0.057).(ABSTRACT TRUNCATED AT 250 WORDS)     

Multicenter registry of angioplasty therapy of cardiogenic shock: initial and long-term survival

This retrospective multicenter study reviews the role of acute percutaneous transluminal coronary angioplasty in the treatment of cardiogenic shock complicating acute myocardial infarction to determine whether early reperfusion affects in-hospital and long-term survival. From 1982 to 1985, 69 patients were treated with emergency angioplasty to attempt reperfusion of the infarct-related artery. Balloon angioplasty was unsuccessful in 20 patients (group 1) and successful in 49 patients (group 2). Initial clinical and angiographic findings in the groups with unsuccessful and successful angioplasty were similar with respect to age (60.5 +/- 2.3 versus 57 +/- 1.8 years), infarct location (65% versus 65% anterior) and gender (65% versus 67% male). Hemodynamic variables in the two groups, including systolic blood pressure (68 +/- 4.3 versus 73 +/- 1.6 mm Hg), left ventricular end-diastolic pressure (24.4 +/- 2.4 versus 27 +/- 1.0 mm Hg) and initial ejection fraction (28.5 +/- 4% versus 32 +/- 2%), were also similar. Twenty-nine patients received thrombolytic therapy with streptokinase; the overall rate of reperfusion was 34%. Group 1 patients had a short-term survival rate of 20%, compared with 69% in group 2 patients (p less than 0.0005). Thirty-eight patients survived the hospital period and were followed up for 24 to 54 months (mean 32.5 +/- 2.4). Five patients (all in group 2) died during follow-up. The long-term incidence rate of congestive heart failure was 19%, arrhythmia 21%, need for repeat angioplasty 17% and coronary artery bypass grafting 26%. Twenty-four month survival was significantly better in group 2 patients (54%) versus group 1 patients (11%, p = 0.003).(ABSTRACT TRUNCATED AT 250 WORDS)     

Possible survival benefit from concomitant beta-but not calcium-antagonist therapy during reperfusion for acute myocardial infarction

To test the hypothesis that long-term beta- or calcium-antagonist therapy begun before the time of myocardial infarction and coronary reperfusion might improve patient in-hospital survival compared with reperfusion alone, 424 consecutive patients successfully reperfused with coronary angioplasty within 12 hours of infarct symptom onset were carefully and retrospectively characterized. Forty-seven patients (11%) were taking beta antagonists and 74 patients (17%) were taking calcium antagonists at the time of infarction. Patients receiving beta antagonists had a more frequent history of hypertension (p less than or equal to 0.001) and prior infarction (p less than or equal to 0.01) than those not so treated and patients receiving calcium antagonists had a more frequent history of prior infarction, prior angina, hypertension and diabetes (all p less than or equal to 0.001) than their nontreated counterparts. Stepwise logistic regression analysis found significant independent correlations between in-hospital death and the following variables: recurrent ischemia (p less than or equal to 0.001); proximal left anterior descending coronary infarct (p less than or equal to 0.001); 3-vessel disease (p = 0.002); patient age (p = 0.004); and initial total occlusion of the infarct artery (p = 0.022). After adjustment for these factors, beta antagonist use (mortality = 0 vs 8% without treatment) was still significantly correlated with improved survival (p = 0.048), whereas calcium-antagonist therapy made no difference in survival. Heart rate and left ventricular end-diastolic pressure upon presentation were significantly lower in patients treated with beta antagonists. Thus, beta-antagonists therapy, but probably not calcium-antagonist therapy, taken before reperfusion for acute myocardial infarction, may improve early survival compared to reperfusion alone. Larger studies will be required to confirm or refute these observations.     

Myocardial infarction with minimal coronary atherosclerosis in the era of thrombolytic reperfusion. The Thrombolysis and Angioplasty in Myocardial Infarction (TAMI) Study Group

The incidence of minimal residual atherosclerotic coronary obstruction after successful intravenous thrombolytic therapy was evaluated in 799 patients with acute myocardial infarction. Minimal residual coronary obstruction (less than or equal to 50%) was observed on selective coronary angiography performed 90 min after initiation of thrombolytic therapy in 43 patients (5.5%). In 42 other patients (5.4%), a greater than 50% but less than 100% residual stenosis noted at 90 min demonstrated further resolution of obstruction to less than 50% at an angiographic follow-up study 7 to 10 days later. Patients with minimal residual coronary obstruction were significantly younger (52 +/- 10.7 versus 56.7 +/- 10 years; p = 0.002) and had less multivessel coronary disease (p less than 0.001), better initial left ventricular ejection fraction (54 +/- 12% versus 50.2 +/- 11.4%; p = 0.006) and a lower in-hospital mortality rate (1% versus 7%; p = 0.04) than did patients who had a significant (greater than 50%) residual coronary obstruction after intravenous thrombolysis. Long-term follow-up study of patients with a minimal coronary lesion (average 1.5 +/- 0.6 years) and those with significant residual stenosis (average 1.6 +/- 0.7 years) demonstrated that the incidence of death (2.4% in patients with minimal stenosis versus 3.5% in those with significant stenosis) and recurrent myocardial infarction (5% each) were similar in both groups. New strategies are needed to prevent coronary rethrombosis in patients with minimal atherosclerosis after thrombolytic therapy for acute myocardial infarction.     

Hyperoxemic perfusion of the left anterior descending coronary artery after primary angioplasty in anterior ST-elevation myocardial infarction.

OBJECTIVES: To assess left ventricle function recovery, ST-segment changes, and enzyme kinetic in ST-elevation myocardial infarction patients treated with intracoronary hyperoxemic perfusion (IHP) after primary percutaneous coronary intervention and compare them with the results obtained in control patients. BACKGROUND: IHP has been shown to attenuate microvascular reperfusion injury, which may result in poor LV function recovery despite successful primary percutaneous coronary intervention. METHODS: Twenty seven anterior ST-elevation myocardial infarction patients treated < or = 12 hr after symptom onset by primary percutaneous coronary intervention were subjected to selective IHP into the left anterior descending coronary artery for 90 min. They were compared with 24 anterior ST-elevation myocardial infarction control patients matched in clinical and angiographic characteristics and treated with conventional primary percutaneous coronary intervention. Left ventricular function recovery was evaluated by serial 2D contrast echocardiography. RESULTS: Left anterior descending coronary artery recanalization was successful in all patients. After IHP (100% successful, duration 90 +/- 5.4 min), patients showed a 4.8 +/- 2.2 hr shorter time-to-peak creatine kinase release (P = 0.001), a shorter creatine kinase half-life period (23.4 +/- 8.9 hr vs. 30.5 +/- 5.8 hr, P = 0.006), and a higher rate of complete ST-segment resolution (78% vs. 42%, P = 0.01). A significant improvement of mean left ventricular ejection fraction (from (44 +/- 9)% to (55 +/- 11)%, P < 0.001) and wall motion score index (from 1.77 +/- 0.2 to 1.39 +/- 0.4, P < 0.001) was observed at 3 months in IHP patients only. CONCLUSION: After successful primary coronary intervention, IHP is associated with significant left ventricular function recovery when compared to conventional treatment. Enzyme kinetic and ST-segment changes suggest faster and more complete microvascular reperfusion and may explain the salutary effects of this new therapy on left ventricular function.     

Primary angioplasty of unprotected left main coronary artery for acute anterolateral myocardial infarction

BACKGROUND: Mortality of acute unprotected left main coronary artery (LMCA) occlusion is very high. The objectives of this analysis were to determine the effect of primary angioplasty and the impact of cardiogenic shock on unprotected LMCA occlusion-induced acute anterolateral myocardial infarction (AAMI). METHODS: Of 1,736 consecutive patients with acute myocardial infarction (AMI), 38 (2.2%) had LMCA occlusion-induced AAMI with Thrombolysis in Myocardial Infarction (TIMI) flow less than or equal to 2. All were given primary angioplasty. RESULTS: Of these 38 patients, 17 (45%) were discharged, and 21 (55%) died in-hospital. Cardiogenic shock was overt in 28 patients; 47.1% of the survival group and 95.2% of the mortality group (p=0.0008). On arrival, the survival-group had higher pH (7.40+/-0.10 vs. 7.30+/-0.14; p=0.013) and base excess (-4.5+/-3.9 vs. -10.4+/-6.0 mEq/L; p=0.0013). In the survival group reperfusion was successful in 100% of patients, as opposed to 57.1% in the mortality group (p=0.0020), and the incident of stenting was not different between the two groups (64.7% vs. 71.4%, p=0.66). Shock patients had lower successful angioplasty rate (67.9% vs. 100%, p=0.040), higher in-hospital mortality (71.4% vs. 10.0%, p=0.0008), and higher 1-year mortality rates (p=0.0064), than stable patients. All shock patients with failed angioplasty died, but the mortality rate was 57.9% (p=0.021) when angioplasty was successful. CONCLUSIONS: Patients presenting with AAMI, LMCA occlusion, and cardiogenic shock have poor survival regardless of primary angioplasty in conjunction with coronary stents. Nevertheless, primary angioplasty is a feasible and effective procedure, and it may save lives in this clinical setting.     

Relationship between tissue reperfusion and postinfarction left ventricular remodelling in patients with anterior wall myocardial infarction treated with primary coronary angioplasty

INTRODUCTION: Pathological left ventricular remodelling is considered the main cause of heart failure in patients after myocardial infarction. AIM: The purpose of this study was to evaluate correlations between the degree of coronary microvascular reperfusion assessed by means of the angiographic myocardial blush grade (MBG) scale and adverse left ventricular remodelling in patients with acute myocardial infarction treated with primary coronary angioplasty. METHODS: This study involved 92 consecutive patients, hospitalised because of their first anterior wall myocardial infarction, who underwent successful (TIMI-3 grade flow) primary coronary angioplasty. Angiographic myocardial reperfusion parameters (MBG, corrected TIMI Frame Count) were assessed. Three days and 6 months after the index PCI all patients underwent an echocardiographic examination and such parameters as end-diastolic volume (EDV), left ventricular ejection fraction (EF) and contractility index (WMSI) were calculated. RESULTS: The patients were divided into two groups: group 1 with impaired myocardial reperfusion (MBG 0-1) (n=32) and group 2 with adequate tissue reperfusion (MBG 2-3) (n=60). Negative left ventricular remodelling was observed more frequently in group 1 than in group 2 (28.1% vs 10%, p=0.029). More patients in group 1 presented heart failure symptoms (56.3% vs 25%, p=0.013). CONCLUSIONS: Failure of tissue reperfusion assessed by means of angiographic indices (MBG 0-1) in patients with myocardial infarction treated with primary coronary angioplasty is associated with a higher rate of adverse myocardial remodelling and heart failure at 6 months after myocardial infarction.     

Clinical course and long-term prognosis in patients with recurrent myocardial infarction

Retrospective study was based on analysis of 881 patients treated in our ward in 1992-1996. Their fate was estimated through 2-6 years after the past myocardial infarction (MI). There were among of them 147 (16.7%) with second and 20 (2.3%) with third or next MI. Then we compared in-hospital course and long-term prognosis in patients with recurrent MI (group I, n = 167) to patients with the first MI (group II, n = 714). We have also evaluated influence of the time-period between the both episodes of myocardial infarctions on the prognosis. The chi-square test was applied to identify the significance of the difference between both groups. Using the Kaplan-Meier method, figures of survival curves were created. Patients in group I were about 4.9 year-older than in group II/(median age was 64.8 +/- 10.7 vs 59.9 +/- +/- 11.3 years p < 0.05). More popular were also diabetes (30.5% vs 18.5%, p < 0.001), advanced hypertension (31.7% vs 20.5% p < 0.01) and higher ratio of current smokers (51.5%) among risk factors in patients from group I. Second myocardial infarction had more serious in-hospital course than the first one. It could be the result of anterior location and more often cardiac complications like ventricular arrhythmias including VF, disturbances of intraventricular conductions, cardiogenic shock and pulmonary oedema with especially of first hours of acute myocardial infarction. Mortality rate in the group I was 2.2 times higher to compare with group II (24.0% vs 10.9%, p < 0.001). Significance higher mortality was in the first year of follow-up and among patients with recurrent myocardial infarction within 12 months after the first one. CONCLUSION: Previous myocardial infarction is significant risk factor that elevate in-hospital course and long-term mortality rate. We observed the higher mortality rate when the recurrent myocardial infarction occurred within 12 months after the first one. The longer time-period since the first myocardial infarction the better prognosis was observed in our analysis.     

Myocardial perfusion grade and survival after percutaneous transluminal coronary angioplasty in patients with cardiogenic shock

We sought to evaluate myocardial reperfusion and its prognostic value after percutaneous transluminal coronary angioplasty (PTCA) in patients admitted for cardiogenic shock. Lack of myocardial reperfusion despite restored coronary flow affects the survival of patients with acute myocardial infarction (AMI). Myocardial blush grade (MBG) is an angiographic measure of myocardial perfusion. We assessed MBG in 41 consecutive patients admitted to our department within 12 hours from the onset of AMI and in cardiogenic shock. PTCA was successful in 83% of patients. Thrombolysis In Mycardial Infarction (TIMI) grade 3 flow was demonstrated in 22 patients (53%). MBG 2/3 was found in 14 patients (34%); among them, 12 had TIMI 3 flow. Compared with patients with MBG 2/3, those with MBG 0/1 were older (71 +/- 11 vs 57 +/- 13 years, p = 0.001), had a higher prevalence of diabetes (48% vs 14%, p = 0.04) and hypertension (63% vs 29%, p = 0.04), showed a trend toward longer ischemic time (6.1 +/- 2.4 vs 4.9 +/- 1.1), and had larger enzymatic infarct size (peak creatine kinase 7,690 +/- 3,516 vs 5,500 +/- 2,977 IU/L). Mortality was higher in patients with MBG 0/1 both in the hospital (81% vs 14%, p <0.001) and at follow-up (81% vs 29%, p = 0.001). After adjustment by multivariate analysis, MBG 0/1 (odds ratio 16, p = 0.01) and age (odds ratio 3.8/10 years, p = 0.04) were correlated with in-hospital mortality. MBG 2/3 was achieved in a few patients in cardiogenic shock after AMI who were treated with PTCA; this was a strong predictor of in-hospital survival. Also, risk stratification after mechanical revascularization should include assessment of restoration of myocardial reperfusion.     

Early recovery of left ventricular function after thrombolytic therapy for acute myocardial infarction: an important determinant of survival

Thrombolytic therapy for acute myocardial infarction reduces early mortality, but full recovery of left ventricular function after reperfusion is delayed. Therefore, the relations among reperfusion, survival and the time course of left ventricular functional recovery were examined in 226 patients treated with intracoronary streptokinase; 77% (134 patients) had sustained reperfusion and 31 patients had no reperfusion or had reocclusion by day 3. Wall motion was measured from contrast ventriculograms performed in the acute period and 3 days later in the central and peripheral infarct regions and the noninfarct region by the centerline method in 165 patients. Patients with reperfusion had better survival (p less than 0.05, mean follow-up 4.5 years) and a higher ejection fraction at 3 days (52 +/- 12 versus 46 +/- 10%, p less than 0.02) attributable to a significantly different change in peripheral infarct region function between the acute and 3 day studies (0.1 +/- 1.0 versus -0.3 +/- 0.9 SD, p less than 0.05). These early functional changes were significant in patients with anterior myocardial infarction and showed similar trends in those with inferior myocardial infarction. On Cox regression analysis, function measured at 3 days was more predictive of survival than was function measured acutely (chi square for acute ejection fraction = 11.48 versus 24.59 at 3 days). Although, as previously reported, greater than 45% of total recovery of left ventricular function occurs later, the ejection fraction achieved by day 3 is already predictive of survival. Thus, the mechanism by which successful thrombolytic therapy enhances survival is improvement of regional and global left ventricular function early after acute myocardial infarction.     

Abrupt withdrawal of beta-blockade therapy in patients with myocardial infarction: effects on infarct size, left ventricular function, and hospital course

The effects of abrupt withdrawal or continuation of beta-blockade therapy during acute myocardial infarction were evaluated in 326 patients participating in the Multicenter Investigation of the Limitation of Infarct Size (MILIS). Thirty-nine patients previously receiving a beta-blocker and randomly selected for withdrawal of beta-blockers and placebo treatment during infarction (group 1) were compared with 272 patients previously untreated with beta-blockers who were also randomly assigned to placebo therapy (group 2). There were no significant differences between the two groups in MB creatine kinase isoenzyme (15.8 +/- 10.9 vs 18.2 +/- 14.4 g-eq/m2, respectively) estimates of infarct size, radionuclide-determined left ventricular ejection fractions within 18 hr of infarction (0.44 +/- 0.15 vs 0.47 +/- 0.16) or 10 days later (0.42 +/- 0.14 vs 0.47 +/- 0.16), creatine kinase-determined incidence of infarct extension (13% vs 6%), congestive heart failure (43% vs 37%), nonfatal ventricular fibrillation (5% vs 7%), or in-hospital mortality (13% vs 9%). Patients in group 1 had more recurrent ischemic chest pain (p = .002) within the first 24 hr after infarction, but not thereafter. However, this did not appear to be related to a rebound increase in systolic blood pressure, heart rate, or double product. In a separate analysis, 20 propranolol-eligible group 1 patients randomly selected for withdrawal of beta-blockade (group 3) were compared with 15 patients randomly selected for continuation of prior beta-blockade therapy (group 4). This comparison yielded similar results. These data indicate that the beta-blockade withdrawal phenomenon is not a major clinical problem in patients with acute myocardial infarction. beta-Blockade therapy can be discontinued abruptly during acute myocardial infarction if clinically indicated.     

Determinants of the need for early acute intervention in patients treated conservatively after thrombolytic therapy for acute myocardial infarction. TAMI-5 Study Group

This study sought to determine whether clinical variables can be used to identify patients at high risk of recurrent spontaneous myocardial ischemia or hemodynamic compromise during the 1st 4 days after intravenous thrombolysis for acute myocardial infarction. Of 288 patients randomly assigned to a conservative postthrombolysis strategy, 54 (19%) required urgent cardiac catheterization within 24 h; 75 (26%) underwent urgent cardiac catheterization within 4 days of admission. Of the clinical variables examined by multiple logistic regression analysis, only patient age and anterior wall myocardial infarction correlated with the need for urgent cardiac catheterization (p = 0.0016 and p = 0.017, respectively). Compared with recombinant tissue-type plasminogen activator or urokinase monotherapy, combination therapy with these agents was associated with a lower need for acute intervention during the 1st 24 h after admission, but the difference did not reach statistical significance (14% for combination therapy vs. 21% for each agent alone, p = 0.30). Of the 75 patients undergoing urgent coronary angiography, only 39% had an occluded infarct-related artery. Emergency coronary angioplasty was performed in 49% of the patients and coronary artery bypass graft surgery was performed urgently in 3%. Despite these interventions, the need for urgent cardiac catheterization was associated with an in-hospital mortality rate of 7% (vs. 3% in the group not requiring urgent angiography, p = 0.36); mean left ventricular ejection fraction was 50.5 +/- 11% (vs. 54.3 +/- 10.8%, p = 0.12) and regional infarct zone wall motion was -2.68 +/- 1.07 SD/chord (vs. -2.46 +/- 1.19 SD/chord; p = 0.44).(ABSTRACT TRUNCATED AT 250 WORDS)     

Influence of baseline ejection fraction and success of thrombolysis on mortality and ventricular function after acute myocardial infarction

The efficacy of streptokinase (STK) thrombolytic therapy was prospectively evaluated in 77 consecutive patients presenting within 9 hours of onset of acute myocardial infarction. Serial left ventricular (LV) ejection fraction (EF) was assessed by radionuclide ventriculography, initially (acute) and at 1 month (late). The role of initial LVEF was examined by comparing patients with an acute LVEF greater than or equal to 50% (type I) with those with LVEF less than 50% (type II). Sixty-five patients (84%) had total coronary occlusion and received STK. Initial successful reperfusion was achieved in 34 patients (52%), but repeat angiograms at 10 to 14 days revealed persistent patency in only 27 patients. Within the type I and type II classification, 2 patient subgroups were compared: Group A had successful and persistent thrombolysis and group B had initial failure of thrombolysis or in-hospital reocclusion. There was no significant change in global LVEF in any group from acute to 1 month follow-up: group IA--acute EF = 56 +/- 2% (mean +/- standard error of the mean), late EF = 55 +/- 2% (p = not significant [NS]); group IB--acute EF = 58 +/- 1%, late EF = 55 +/- 2% (NS); group IIA--acute EF = 35 +/- 2%, late EF = 4 +/- 4%, (NS); group II B--acute EF = 36 +/- 2%, late EF = 41 +/- 3% (NS). No patient with an acute EF greater than or equal to 50% died, i.e., group IA patients (n = 7) or group IB patients (n = 13).(ABSTRACT TRUNCATED AT 250 WORDS)     

Early intervention in acute myocardial infarction: significance for myocardial salvage of immediate intravenous streptokinase therapy followed by coronary angioplasty

Sixteen patients with acute myocardial infarction underwent treatment with streptokinase up to 3 hours after the onset of chest pain. Nine patients (group I) received streptokinase within 1 hour of the onset of pain, and seven patients (group II) received it within 2 to 3 hours. All underwent multigated radionuclide ventriculography after streptokinase therapy and 1 week later. Percutaneous transluminal coronary angioplasty of the infarct artery was performed within 24 hours in all patients. An effort-limited treadmill stress test was performed before discharge. There was no mortality or serious complication. Mean peak total creatine kinase was 521 +/- 289 mU/ml in group I, and 1,614 +/- 709 mU/ml in group II (p less than 0.05). The mean initial left ventricular ejection fraction was 47 +/- 11% in group I and 37 +/- 10% in group II. After early angioplasty (within 24 hours) and at 1 week recovery, left ventricular ejection fraction increased to 53 +/- 9% in group I (p less than 0.05) and to 40 +/- 7% in group II (p = NS). Seven of the nine patients in group I had normal radionuclide ventriculograms at discharge compared with none of the seven patients in group II. Thrombolytic therapy administered less than 1 hour after the onset of symptoms of acute myocardial infarction followed by angioplasty of the infarct artery results in preservation of left ventricular function, whereas therapy given after 2 hours has only a limited effect.     

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.     

Significance of a negative exercise thallium test in the presence of a critical residual stenosis after thrombolysis for acute myocardial infarction

BACKGROUND. After thrombolytic therapy for acute myocardial infarction, increasing emphasis is placed on early submaximal exercise testing, with further intervention advocated only for demonstrable ischemia. Although significant residual coronary artery lesions after successful thrombolysis are common, many patients paradoxically have no corresponding provokable ischemia. METHODS AND RESULTS. The relation between significant postthrombolytic residual coronary artery disease and a negative early, submaximal exercise thallium-201 tomogram was studied among 101 consecutive patients with uncomplicated myocardial infarction and at least 70% residual stenosis of the infarct artery. A negative test occurred in 49 (48.5%) patients with a mean 88% residual infarct artery stenosis. Further characteristics of the group were as follows: mean time to treatment was 3.1 hours; mean age was 54 +/- 10 years; 80% were male; 47% had anterior infarction; 39% had multivessel disease; mean left ventricular ejection fraction was 53 +/- 14%; and mean peak creatine kinase level was 3,820 +/- 3,123 IU/ml. A similar group of 52 (51.5%) patients, treated within 3.3 hours from symptom onset, with a mean postthrombolysis stenosis of 90%, had a positive exercise test. Characteristics of this group were as follows: age was 58 +/- 10 years; 92% were male; 56% had anterior infarction; 40% had multivessel disease; and mean left ventricular ejection fraction was 54 +/- 15%. The peak creatine kinase level associated with the infarction, however, was lower: 2,605 +/- 1,805 IU/ml (p = 0.04). There was no difference in performance at exercise testing with respect to peak systolic pressure, peak heart rate, or time tolerated on the treadmill between the two groups. By multivariate logistic regression, only peak creatine kinase level predicted a negative stress result in the presence of a significant residual stenosis (odds ratio, 4.2; 95% confidence interval, 1.1-16.3). CONCLUSIONS. The explanation for the relatively frequent finding of a negative early stress 201Tl tomogram after apparently successful reperfusion appears to be more extensive myocardial necrosis and not delay in therapy or inadequate exercise performance.     

Myocardial viability in patients with Q wave myocardial infarction and no residual ischemia.

BACKGROUND. Coronary revascularization in patients with persistent angina after myocardial infarction reduces the incidence of recurrent angina pectoris and myocardial infarction and improves left ventricular function. The results of revascularization after a Q wave myocardial infarction when there is no residual ischemia may depend on myocardial viability. METHODS AND RESULTS. To determine whether there was viable myocardium in the infarct area in the absence of clinical and scintigraphic evidence of myocardial ischemia, 15 asymptomatic patients with a Q wave myocardial infarction, no redistribution on stress 201Tl test, and single-vessel disease (greater than 70% stenosis) with persistent anterograde blood flow were randomized to percutaneous transluminal coronary artery angioplasty (PTCA) or conservative medical treatment. After 2 months of follow-up, mean coronary blood flow measured by Doppler catheter in the infarct-related artery was higher in the PTCA treatment group (33 +/- 6 ml/min, n = 8) than in the conservative treatment group (16 +/- 4 ml/min, n = 7; p less than 0.05 between groups). The 201Tl pathological-to-normal ratios measured on postexercise images did not change in patients treated conservatively during the follow-up period (delta = +1.1 +/- 2.2%; NS from baseline) but increased significantly in patients treated by PTCA (delta = +8.5 +/- 2.3%; p less than 0.01 from baseline; p less than 0.05 between groups). Segmental wall motion improved on left ventricular angiography 2 months after PTCA (delta = +11.5 +/- 2.2%; p less than 0.001 from baseline) significantly more than in the conservative treatment group (delta = +4.1 +/- 1.4%; p less than 0.05 between both groups). Improvements of 201Tl ratios and segmental wall motion indexes correlated significantly (r = 0.73, p = 0.002). The mild improvement of global left ventricular ejection fraction measured in the PTCA treatment group did not differ significantly from changes in the conservative treatment group. CONCLUSIONS. Successful angioplasty of the stenotic infarct artery in patients with a Q wave myocardial infarction and no residual ischemia improved coronary flow, 201Tl uptake in the infarct area, and regional wall motion. Therefore, myocardial viability may last several weeks, as long as residual blood flow persists in the infarct-related artery. Optimal assessment of viability by imaging techniques should identify patients who are most likely to benefit from revascularization.     

Coronary angioplasty as primary therapy for acute myocardial infarction 6 to 48 hours after symptom onset: report of an initial experience

Recent randomized trials in acute myocardial infarction suggest that infarct size reduction need not be achieved for intravenous streptokinase to improve patient survival. If this is the case, attempts to achieve late revascularization may be justified. To assess the results of late primary coronary angioplasty performed in the setting of acute myocardial infarction, the clinical and angiographic data as well as hospital outcome of 139 consecutive patients treated with coronary angioplasty without prior thrombolytic therapy 6 to 48 h after the onset of chest pain (late group) were compared with those of 117 patients treated with primary angioplasty less than 6 h after the onset of chest pain (early group); time to angioplasty was assessed as a covariate of survival. In the 139 patients treated greater than or equal to 6 h after the onset of chest pain, the mean age (+/- SD) was 57 +/- 12 years and the median time to angioplasty was 15 h; 61% had multivessel disease, 14% were in cardiogenic shock and the mean left ventricular ejection fraction was 44 +/- 12%. Angioplasty was successful (final diameter stenosis less than 70% and Thrombolysis in Myocardial Infarction [TIMI] flow grade greater than or equal to 2) in 78% of patients. Successful angioplasty was associated with a 5.5% in-hospital mortality rate, whereas unsuccessful angioplasty was associated with a 43% hospital mortality rate (p less than 0.001). Multivariate testing in all patients identified four independent predictors of in-hospital death: cardiogenic shock (p less than 0.001), unsuccessful angioplasty (p = 0.001), ejection fraction less than or equal to 30% (p = 0.002) and patient age (p = 0.004).(ABSTRACT TRUNCATED AT 250 WORDS)     

Angiographic predictors of left ventricular ejection fraction after successful angioplasty in acute myocardial infarction: an angiographic risk score for use in the catheterization laboratory.

We investigated the value of angiographic parameters in patients with successful primary angioplasty using a simple angiographic risk score. In 608 consecutive patients, we assessed the infarct-related artery, antegrade flow before treatment, presence of distal embolization, and myocardial blush grade after coronary angioplasty. LAD-related infarction (OR = 8.4; 3 points), TIMI 0-2 flow before angioplasty (OR = 2.2; 1 point), myocardial blush 0 or 1 (OR = 2.5; 1 point), and distal embolization (OR = 2.2; 1 point) were independent predictors of left ventricular ejection fraction (LVEF) < or = 40% after successful angioplasty. Patients with 0 (minimum) or 1 point have LVEF of 49.5% +/- 8.4% and 30-day mortality of 0.8%. Patients with 2-3 points have LVEF of 44.9% +/- 10.3% and 30-day mortality of 2.8%. Patients with 4 points have LVEF of 38.2% +/- 10.8% and 30-day mortality of 2.7%. Patients with 5-6 (maximum) points have LVEF of 32.0% +/- 9.4% and 30-day mortality of 6.9%. A simple angiographic score predicts LVEF and mortality in patients when leaving the catheterization laboratory after successful primary angioplasty for acute myocardial infarction.     

Late effects of intracoronary streptokinase on regional wall motion, ventricular aneurysm and left ventricular thrombus in myocardial infarction: results from the Western Washington Randomized Trial

To determine whether intracoronary streptokinase improves late regional wall motion or reduces left ventricular aneurysm or thrombus formation in patients with acute myocardial infarction, two-dimensional echocardiography was performed at 8 +/- 3 weeks after infarction in 83 patients randomized to streptokinase (n = 45) or standard therapy (n = 38) in the Western Washington Intracoronary Streptokinase Trial. Among the patients treated with streptokinase, the average time to treatment was 4.7 +/- 2.5 hours after the onset of chest pain, and 67% had successful reperfusion. Regional wall motion was assessed in nine left ventricular segments on a scale of 1 to 4 (normal, hypokinetic, akinetic and dyskinetic). Left ventricular thrombus formation was interpreted as positive, equivocal or negative. All patients received anticoagulant therapy in the hospital and 52 received such therapy after hospital discharge. The mean (+/- SD) global (1.5 +/- 0.4 in both groups) and regional wall motion scores in the streptokinase-treated and control groups were not significantly different. The prevalence of aneurysm was 16% in both groups. Left ventricular thrombus was identified in only five patients (positive identification in four, and equivocal in one), all in the streptokinase-treated group (p = NS). There were also no differences between streptokinase and control treatment in any of the echocardiographic variables in subgroups of patients with anterior infarction, inferior infarction, no prior infarction or reperfusion with streptokinase. It is concluded that intracoronary streptokinase given relatively late in the course of acute myocardial infarction does not result in improved global or regional wall motion or a reduction in left ventricular thrombus or aneurysm formation in survivors studied 2 months after myocardial infarction.