Risk Of Reocclusion Research Articles

High-grade infarct-related stenosis after successful thrombolysis: Strong predictor of reocclusion, but not of clinical reinfarction

Background After successful thrombolysis, a high-grade stenosis at 24-hour angiography is strongly predictive of reocclusion and is often believed to result in high reinfarction rates. However, routine angioplasty did not reduce death or reinfarction in past trials. Systematic angiographic follow-up shows that reocclusion often occurs without clinical reinfarction. This study investigates whether the increased risk for reocclusion associated with a high-grade lesion translates into impaired clinical outcome. Methods In the ischemia-guided Antithrombotics in the Prevention of Reocclusion in COronary Thrombolysis (APRICOT-1) trial, 240 patients with ST-elevation MI who had an open infarct artery 24 hours after thrombolysis had 3-month repeat angiography to assess reocclusion, with clinical follow-up at 3 months and 3 years. Results On the basis of the optimal discriminative stenosis severity, the reocclusion rate was 40% (47/118) in patients with a high-grade residual stenosis and 16% (20/122) in patients with a low-medium-grade lesion (risk ratio [RR], 2.43; 95% CI, 1.54–3.84; P <.01). Three-month death and reinfarction rates did not differ: 6% (7/118) versus 9% (11/122; RR, 0.66; 95% CI, 0.26–1.64; P = not significant). Systematic angiographic follow-up revealed that reocclusion of a high-grade lesion occurred in the absence of clinical reinfarction in 85% (40/47) of patients, as compared with 45% (9/20) in patients with a low-medium-grade stenosis (RR, 1.89; 95% CI, 1.15–3.12; P <.01). Despite an independent association with reocclusion, a high-grade stenosis was not predictive of either short- or long-term death and reinfarction. Conclusions After successful thrombolysis and adopting an ischemia-guided revascularization strategy, patients with a high-grade stenosis experience death/reinfarction rates similar to that of patients with a low-medium-grade lesion. This is true despite a 2- to 3-fold higher risk for reocclusion. The finding that reocclusion of a high-grade lesion often occurs without clinical reinfarction explains the absence of a relationship between a severe stenosis and death/reinfarction. Appreciation of these observations may contribute to an optimal design of a future randomized trial to re-evaluate the impact of a routine invasive strategy.

Coronary and myocardial angiography: angiographic assessment of both epicardial and myocardial perfusion.

Angiographic assessment of epicardial coronary artery blood flow has played a pivotal role in our understanding of the “time-dependent open artery hypothesis” and in the evaluation of reperfusion strategies over the past 2 decades.1–8 It has become increasingly apparent, however, that clinical outcomes are not only associated with angiographic flow in the epicardial artery, but also with angiographic flow in the myocardium.9–13 To this end, the goal of reperfusion therapies has shifted to include reperfusion downstream at the level of capillary bed, and it might be more appropriate that the hypothesis now be termed “the time dependent open artery and open microvascular hypothesis.” The goal of this article is to review angiographic methods used to evaluate myocardial ischemia and infarction and to discuss the insights into the pathophysiology of acute coronary syndromes provided by these angiographic indexes of coronary artery blood flow and myocardial perfusion. For nearly 2 decades now, the Thrombolysis In Myocardial Infarction (TIMI) flow grade classification scheme has been successfully used to assess coronary blood flow in acute coronary syndromes1 (Table). It has been a valuable tool to compare angiographic outcomes following reperfusion, and the association of the TFGs with clinical outcomes (including mortality) has been well documented.2–8 The relationship between TFG and mortality does satisfy what some consider to be 3 criteria required to validate a surrogate end point for mortality, as follows: (1) There is an association between TIMI grade 3 flow and mortality, (2) an agent such as recombinant tissue plasminogen activator improves TIMI grade 3 flow by 22% over another agent such as streptokinase, and (3) the agent tissue plasminogen activator improves mortality 1.1% over streptokinase. View this table: Definitions of the TFG and the TMPG Systems On the basis of this relationship between TIMI flow and mortality observed in the GUSTO …

Determinants of target vessel failure in chronic total coronary occlusions after stent implantation: The influence of collateral function and coronary hemodynamics

ObjectivesThe goal of this study was to assess the influence of collateral function, coronary hemodynamics, and the angiographic result on the risk of target vessel failure (TVF) after recanalization of a chronic total coronary occlusion (CTO). BackgroundCollaterals may have an adverse effect on TVF. MethodsIn 111 consecutive patients, a CTO (duration >2 weeks) was successfully recanalized with stent implantation. Collateral function was assessed by intracoronary Doppler flow velocity and pressure recordings distal to the occlusion. Baseline collateral function was determined before the first balloon inflation, and recruitable collateral function after stenting during a balloon reocclusion. Finally, the coronary flow velocity reserve (CFVR) and the fractional flow reserve (FFR) were measured. ResultsAngiographic follow-up after 5 ± 1.4 months in 106 patients showed a reocclusion in 17% and a restenosis in 36%. The major determinants of TVF were the stent length (p < 0.01) and number of implanted stents (p < 0.01). No difference was observed in baseline or recruitable collateral function between patients with and without TVF; 52% of patients had a CFVR ≥2.0, and only 18% a CFVR ≥2.5 after percutaneous transluminal coronary angioplasty, but neither cutoff-value predicted TVF. A low FFR discriminated patients with reocclusion (0.81 ± 0.07 vs. 0.86 ± 0.08, p < 0.05) but not with restenosis (0.87 ± 0.06). ConclusionsThis study showed that there is no relation between a well-developed collateral supply and the risk of TVF in recanalized CTOs. This was rather determined by the stented segment length. There was also no adverse effect of the frequently observed impaired CFVR on TVF, whereas a low FFR was associated with a higher risk of reocclusion.

Do good collaterals increase the risk of reocclusion after recanalization of a chronic coronary occlusion?

Do good collaterals increase the risk of reocclusion after recanalization of a chronic coronary occlusion?

Emerging concepts in the management of acute myocardial infarction in patients with diabetes mellitus

Although fibrinolysis has improved survival of patients after myocardial infarction (MI), such therapy is less likely to be administered to patients with diabetes. Furthermore, these patients present later (15 min) than nondiabetics. Moreover, even with the use of early potent fibrinolytic agents, patients with diabetes continued to suffer excessive morbidity and mortality. This finding is not related to the ability of fibrinolytic agents to restore complete reperfusion or increased risk of reocclusion of the infarct-related artery. Instead, the impaired ventricular performance at the noninfarct areas and metabolic derangements during the acute phase of MI may account for the adverse outcome. The efficacy of percutaneous coronary revascularization procedures for treatment of acute MI requires further evaluation. Therapeutic approaches should consider correcting these abnormalities to afford greater survival benefit for this subset of high-risk patients.

Complex stenosis morphology predicts late reocclusion during follow-up after myocardial infarction in patients with patent infarct–related coronary arteries

Background Whether angiographic morphology of infarct-related residual stenoses continues to affect prognosis after discharge is not known. Methods We studied 175 patients after their myocardial infarction who required nonurgent coronary angioplasty for residual myocardial ischemia. The findings at diagnostic coronary angiography were compared with those before angioplasty (mean of 7 months later). Infarct-related stenoses were classified as complex or smooth. Stenosis progression was defined as >0.5 mm diameter reduction. Results One hundred twenty-one (69%) infarct-related stenoses were complex. At restudy, total occlusion was found in 41 (35%) of the infarct-related complex stenoses compared with 7 (13%) smooth stenoses ( P = .001). Reocclusion occurred in 16 (55%) of 29 complex infarct-related stenoses with thrombus, compared with 25 (28%) of 88 without thrombus ( P = .01). During follow-up, 46 patients (26%) had cardiac events. Of these, 70% had complex lesions at study entry compared with 30% smooth ( P < .05). Conclusions Residual angiographically complex stenoses after an uncomplicated myocardial infarction are associated with a greater risk of reocclusion and may predispose to coronary events at follow-up. (Am Heart J 1998;136:877-83.)

Plasma resistance to activated protein C regulates the activation of coagulation induced by thrombolysis in patients with ischaemic heart disease.

OBJECTIVE: To determine whether there was a relation between plasma resistance to activated protein C and the coagulation activation induced during thrombolysis with 100 mg alteplase in 25 patients with...

Variable Platelet Response to Low-dose ASA and the Risk of Limb Deterioration in Patients Submitted to Peripheral Arterial Angioplasty

A group of 100 patients with intermittent claudication (70 male, 30 female), treated with I00 mg ASA per day, were followed over 18 months after elective percutaneous balloon angioplasty. Platelet function was monitored over a period of 12 months by corrected whole blood aggregometry (CWBA). Upon stimulation by arachidonic acid (AA), adenosine diphosphate (ADP) and collagen, CWBA-results were obtained by an electronic acquisition and evaluation system correcting for hematocrit and platelet count of the blood sample. All patients showed a completely inhibited platelet response to AA stimulation. Comparison of the CWBA-results with clinical parameters revealed that reocclusions at the site of angioplasty occurred exclusively in male patients for which CWBA failed to prove an inhibition of aggregation upon both agonists, ADP and collagen, and for these patients the risk of complication is at least 87% higher (p = 0.0093). Only 40% of male patients show the expected effect of ASA on in vitro platelet aggregation at any given point in time and CWBA is capable of predicting those male patients which are at an elevated risk of reocclusion following peripheral angioplasty.

Evidence for a pivotal role of platelets in vascular reocclusion and restenosis

Reocclusion and restenosis continue to be the major clinical complications following emergency and elective coronary interventions. Reocclusion ultimately occurs in more than 25% of patients after successful thrombolysis for acute myocardial infarction [l] and may have major adverse consequences, ranging from mortality to compromised cardiac function. After percutaneous transluminal coronary angioplasty (PTCA), the risk associated with acute occlusion leading to myocardial infarction, emergency repeat PTCA, or coronary bypass surgery, may occur in up to 8% of patients [2]. Even more frequent and to date resistant to therapy is the possibility of restenosis, which occurs in 30-40% of patients after PTCA and requires an additional percutaneous intervention or bypass operation within the following year. Substantial evidence directly implicates platelets in reocclusion and restenosis. In fact, current clinical data suggest that platelets represent the most beneficial therapeutic target to reduce the risk of reocclusion and restenosis. In line with this “controversy series” thrombin is being considered the alternative to platelets in the pathogenesis of vascular reocclusion and restenosis. By virtue of its capacity to mediate fibrin formation, platelet activation and cellular migration and proliferation, thrombin undoubtedly is an important player in reocclusion and restenosis. Nevertheless, thrombin inhibitors have yet to match the dramatic effects of platelet antagonists in patients.

Effect on collagen metabolism of thrombolytic therapy with tissue‐plasminogen activator. A randomized, placebo‐controlled study

This paper assesses alterations in collagen metabolism following thrombolytic therapy of acute myocardial infarction with tissue-plasminogen activator. Sequential serum measurements of the amino-terminal propeptide of type III procollagen (S-PIIINP) and the carboxyterminal propeptide of type I collagen (S-PICP) in patients suspected of acute myocardial infarction randomized to tissue-plasminogen activator or placebo were used. S-PIIINP increased at 3 h in patients with acute myocardial infarction treated with tissue-plasminogen activator (P < 0.05). S-PIIINP was higher in patients treated with tissue-plasminogen activator compared with placebo-treated patients at 3 and 6 h (P < 0.05). S-PICP decreased independently of therapy and diagnosis. Tissue-plasminogen activator, therefore, induces breakdown of collagen, some of which is located in the wall of atheromatous arteries. Vascular patency following thrombolytic therapy may partly be mediated by breakdown of thrombogenic collagen in the vessel wall. The findings may suggest a role for S-PIIINP as a non-invasive indicator of the risk of reocclusion.

Early angiography cannot predict postthrombolytic coronary reocclusion: Observations from the GUSTO angiographic study

Objectives. The purpose of this study was to determine whether early qualitative or quantitative angiographic features can predict reocclusion after initially successful coronary thrombolysis.Background. Although both the benefits of early reperfusion and the consequences of subsequent reocclusion after thrombolysis for acute myocardial infarction have been well described, efforts to describe angiographic markers of lesions at high risk for reocclusion have produced conflicting results. The Global Utilization of Streplokinase and t-PA for Occluded Coronary Arteries (GUSTO) angiographic trial provides the opportunity to examine these relations in the largest single, prospective patient cohort studied to date.Methods. We studied 559 patients undergoing follow-up angiography at 90 min and 5 to 7 days after thrombolysis in the GUSTO trial. Patients received one of four thrombolytic regimens: 1) streptokinase with intravenous heparin; 2) streptokinase with subcutaneous heparin; 3) accelerated-dose recombinant tissuetype plasminogen activator (rt-PA) with intravenous heparin; or 4) a combination of streptokinase and conventionally dosed rt-PA with intravenous heparin. Qualitative variables examined at 90-min angiography included Thrombolysis in Myocardial Infarction (TIMI) flow grade, visible thrombus and lesion morphology. Quantitative variables included percent diameter stenosis, percent area stenosis minimal lumen diameter and lesion length. The study contained a power > 0.85 to detect clinically important differences in percent diameter stenosis, percent area stenosis and minimal lumen diameter between the groups with subsequent reocclusion and sustained patency at the p = 0.05 level.Results. At follow-up, 33 patients (5.9%) had reocclusion. The reocclusion rate for patients with early TIMI grade 2 flow was 6.3% versus 5.6% for TIMI grade 3 flow (p = NS). When the group with reocclusion was compared with the group with continued patency, there were no differences in presence of early visible thrombus, complex lesion morphology, percent diameter stenosis, percent area stenosis, minimal lumen diameter or lesion length.Conclusions. Our findings demonstrate that neither qualitative nor quantitative angiographic variables at 90 min after initiation of thrombolytic therapy can be used to predict subsequent coronary reocclusion.

Subintimal angioplasty of femoropopliteal artery occlusions: The long-term results

The technique of subintimal angioplasty has been attempted on 200 consecutive femoropopliteal artery occlusions of median (range) length 11 (2-37) cm. The principle of the technique is to traverse the occlusion in the subintimal plane and recanalise by inflating the angioplasty balloon within the subintimal space. The technical success rate was 159/200 (80%) and was not significantly different for occlusions < 10 cm (81%, n = 73), 11-20 cm (83%, n = 63) or > 20 cm (68%, n = 23), p = 0.20. There were no deaths nor limb loss resulting from the procedure. The median (range) ankle-brachial pressure index increased from 0.61 (0.21-1.0) preangioplasty to 0.90 (0.26-1.50) postangioplasty. The actuarial haemodynamic patencies of technically successful procedures at 12 and 36 months were 71% and 58% respectively, the symptomatic patencies were 73% and 61%. A multiple regression analysis showed that smoking multiplied the risk of reocclusion by 2.70 (p < 0.001), each additional run-off vessel reduced the risk by 0.54 (p < 0.001) and the risk increased by 1.73 (p = 0.020) for every 10 cm of occlusion length. In conclusion, the technical success rate (80%) of subintimal angioplasty for femoropopliteal occlusions is unrelated to occlusion length and for all procedures, including technical failures, cumulative symptomatic and haemodynamic patencies of 46 and 48% can be achieved at 3 years. The factors influencing long-term patency were smoking, the number of calf run-off vessels and occlusion length.

Fibrinogen, arterial risk factor, in clinical practice

Easil y measured in lar ge series of sam p les , fibrinogen has been extensively studied in the epidemiology of cardiovascular risk factors. Ten large stu­ dies have concluded that fibrinogen is a risk factor of equal or higher value than total cholesterol. In coronary diseases, fibrinogen is an independent risk factor and has a pro­ gnostic value. After stroke, high fibrinogen level is an index of severity. In peripheral arterial disease, it indicates the risk of reocclusion after surgery. The role of fibrinogen in arterial occlusion is multiple: composition of the atheroma plaque, thrombi formation, endothelial injury, hyperviscosity. Many parameters increase fibrinogen: inflammation, ageing, smoking. Genetic control of fibrinogen is a promising field for future research in epi­ demiology. Many drugs decrease fibrinogen: fibrates, platelet inhibitor ticlopidin and should be used for this purpose. Lastly, physical exercise, if sustained enough, effectively reduces fibrinogen.

Culprit lesion morphology and stenosis severity in the prediction of reocclusion after coronary thrombolysis: Angiographic results of the APRICOT study

Objectives. In the APRICOT study (Antithrombotics in the Prevention of Reocclusion In Coronary Thrombolysis), we sought to determine whether angiographic characteristics of the culprit lesion could predict reocclusion after successful thrombolysis and to analyze the influence of three antithrombotic treatment regimens.Background. After successful thrombolysis, reocclusion is a major problem. Prediction of reocclusion by angiographic data and choice of antithrombotic treatment would be important for clinical management.Methods. After thrombolysis, patients were treated with intravenous heparin until initial angiography was performed within 48 h. Patients with a patent infarct-related artery were eligible. Three hundred patients were randomly selected for treatment with coumadin, aspirin (300 mg once daily) or placebo. Patency on a second angiographic study after 3 months was the primary end point of the study.Results. Reocclusion rate was 25% with aspirin, 30% with coumadin and 32% with placebo (p = NS). Lesions with >90% stenosis reoccluded more frequently (42%) than did those with <90% stenosis (23%) (p < 0.01). Reocclussion rate of smooth lesions was higher (34%) than that of complex lesions (23%) (p < 0.05). In lesions with <90% stenosis, the reocclusion rate was lower with aspirin (17%) than with coumadin (25%) or placebo (30%) (p < 0.01). In complex lesions, the reocclusion rate was lower with aspirin (14%) than with coumadin (32%) or placebo (25%) (p < 0.02). Multivariate analysis showed only stenosis severity >90% to be an independent predictor of reocclusion (odds ratio 2.31, 95% confidence interval 1.28 to 4.18, p = 0.006).Conclusions. Angiographic features of the culprit lesion after successful coronary thrombolysis significantly predict the risk of reocclusion: high grade (>90%) stenoses reoccluded more frequently. Aspirin was effective only in complex and less severe lesions (<90% stenosis). These findings should prompt investigation of the effects of an aggressive approach to patients with sever residual stenosis.

Post thrombolysis management.

Strategies for the evaluation of the post infarction patient need revision in the light of recent findings from thrombolytic trials, and the availability of more effective methods for detecting myocardial viability. A strategy based on determining the risk of re-occlusion from vessel anatomy at coronary angiography and determining the area of myocardium at risk based on sequential analysis of ST segment elevation is discussed.

Aspirin versus coumadin in the prevention of reocclusion and recurrent ischemia after successful thrombolysis: a prospective placebo-controlled angiographic study. Results of the APRICOT Study.

Successful coronary thrombolysis involves a risk for reocclusion that cannot be prevented by invasive strategies. Therefore, we studied the effects of three antithrombotic regimens on the angiographic and clinical courses after successful thrombolysis. Patients treated with intravenous thrombolytic therapy followed by intravenous heparin were eligible when a patent infarct-related artery was demonstrated at angiography < 48 hours. Three hundred patients were randomized to either 325 mg aspirin daily or placebo with discontinuation of heparin or to Coumadin with continuation of heparin until oral anticoagulation was established (international normalized ratio, 2.8-4.0). After 3 months, in which conservative treatment was intended, vessel patency and ventricular function were reassessed in 248 patients. Reocclusion rates were not significantly different: 25% (23 of 93) with aspirin, 30% (24 of 81) with Coumadin, and 32% (24 of 74) with placebo. Reinfarction was seen in 3% of patients on aspirin, in 8% on Coumadin, and in 11% on placebo (aspirin versus placebo, p < 0.025; other comparison, p = NS). Revascularization rate was 6% with aspirin, 13% with Coumadin, and 16% with placebo (aspirin versus placebo, p < 0.05; other comparisons, p = NS). Mortality was 2% and did not differ between groups. An event-free clinical course was seen in 93% with aspirin, in 82% with Coumadin, and in 76% with placebo (aspirin versus placebo, p < 0.001; aspirin versus Coumadin, p < 0.05). An event-free course without reocclusion was observed in 73% with aspirin, in 63% with Coumadin, and in 59% with placebo (p = NS). An increase of left ventricular ejection fraction was only found in the aspirin group (4.6%, p < 0.001). At 3 months after successful thrombolysis, reocclusion occurred in about 30% of patients, regardless of the use of antithrombotics. Compared with placebo, aspirin significantly reduces reinfarction rate and revascularization rate, improves event-free survival, and better preserves left ventricular function. The efficacy of Coumadin on these end points appears less than that of aspirin. The still-high reocclusion rate emphasizes the need for better antithrombotic therapy in these patients.

Microalbuminuria is no risk factor for restenosis following percutaneous transluminal coronary angioplasty.

Microalbuminuria is known to be associated with an increased risk for cardiovascular disease. It is detectable in acute myocardial infarction and could therefore also be a risk factor for reocclusion after percutaneous transluminal coronary angioplasty (PTCA). In our study follow-up coronary angiography was performed in 50 consecutive patients with a mean age of 56 years (38-70) on average 14 months after successful PTCA. Restenosis was defined as a decrease in diameter of 25% or more of the original result and one of at least 50% in vessel diameter. In the restenosis group there were 23 patients, and 27 showed no restenosis. The family history and anamnestic risk profile, results of the initially performed coronary angiography, and laboratory risk factors were comparable in the two groups. Median microalbumin was 11.2 mg/g creatinine in those with restenosis and 9.8 mg/g creatinine in those without. Using a cut-off of 10.0 mg/g creatinine, 12 of 23 patients with restenosis (52%) and 10 of 27 patients without (37%) were positive for microalbuminuria (NS). The incidence of microalbuminuria was higher in both groups compared to historical controls. Thus, in the restenosis group the incidence of microalbuminuria tended to be higher than in the nonrestenosis group, but since this difference did not reach statistical significance, it cannot be used to predict the risk of reocclusion after PTCA.

Emergency coronary angioplasty for acute myocardial infarction--factors affecting acute restenosis in catheterization laboratory and reocclusion during hospitalization.

A total of 107 consecutive patients with acute myocardial infarction underwent emergency coronary angioplasty (PTCA). Restoration of blood flow with TIMI grade III was established by emergency PTCA in 101 patients (94.4%). "Acute restenosis" was defined as a lesion that, when dilated to less than 50%, narrowed again to more than 75% luminar reduction 5 min after the balloon inflation. Acute restenosis occurred in 39 patients (39%). Multivariate analysis selected 3 factors associated significantly with an increased rate of acute restenosis: (1) dissection, (2) small balloon/artery diameter ratio and (3) low systolic blood pressure during PTCA. Reocclusion, which was defined as a total reobstruction of the lesion during hospitalization following emergency PTCA, was examined by predischarge coronary angiography. Acute restenosis correlated significantly with an increase in reocclusion rate. The incidence of documented reocclusion was 12%. Residual stenosis, multivessel disease and irregular dilation correlated significantly with an increased rate of reocclusion. The in-hospital and postdischarge mortalities were 5.6% and 2.1%, respectively. In summary, emergency PTCA produced a high angiographic success rate. Use of adequate balloon size and sufficient dilation correlated significantly with angiographic outcome in emergency PTCA. Patients with acute restenosis, high residual stenosis, irregular dilation, and multivessel disease would have a relatively high risk of reocclusion.

Submaximal exercise thallium-201 SPECT for assessment of interventional therapy in patients with acute myocardial infarction

Submaximal thallium-201 stress testing has been shown to provide important diagnostic and prognostic information in patients with acute myocardial infarction. The purpose of this investigation was to evaluate the diagnostic value of early submaximal stress testing and thallium-201 single photon emission computed tomography (SPECT) after interventional therapy. Scintigraphic results from 56 patients with infarctions, who underwent acute thrombolytic therapy, angioplasty, or both, were compared with late (6 weeks) functional outcome as assessed by radionuclide ventriculography and with results of discharge coronary angiography. A linear correlation was found between the extent of thallium-201 SPECT perfusion defect and late ventricular function ( r = 0.74, p < 0.01). Forty-two percent of patients with large SPECT perfusion defects had normal left ventricular ejection fractions, suggesting an overestimation of infarct size by early imaging. Sensitivity and specificity of thallium-201 SPECT for detection of coronary artery stenosis in noninfarct territories was 57% and 46%, respectively, indicating limited diagnostic definition of extent of underlying coronary artery disease. Results of follow-up coronary angiography showed a significant relationship between the size of the initial perfusion defect and early restenosis or reocclusion of the infarct artery. Thus the extent of early thallium-201 perfusion defects correlates with late functional outcome but appears to overestimate the degree of injury. Submaximal thallium-201 stress testing allows only limited characterization of underlying coronary artery disease. Early assessment of infarct size may identify a patient population at high risk for reocclusion of the infarct artery.

The use of intraaortic balloon pumping as an adjunct to reperfusion therapy in acute myocardial infarction

To assess the risk and possible benefits of use of the percutaneous IABP in patients given thrombolytic therapy as treatment for acute myocardial infarction, we prospectively evaluated 810 consecutive patients entered into the TAMI trials. During hospitalization the 85 patients treated with the IABP had more cardiac risk factors, were slightly older (58 vs 56 years), and more often had anterior infarction (62% vs 38%). At acute cardiac catheterization, patients treated with the IABP also had more multivessel coronary disease (67% vs 43%), more frequent TIMI grade 0 or 1 flow (44% vs 28%), lower global ejection fraction (40% vs 52%), and worse regional infarct (−3.2 vs −2.5 SD/chord) and noninfarct (−0.67 vs + 0.36 SD/chord) zone function. Although mortality rates (32% vs 4%) and in-hospital complications were greater in patients treated with the IABP, a greater improvement in global (delta ejection fraction: + 1.9% vs +0.7%) and noninfarct zone (delta SD/chord: +0.11 vs −0.09) left ventricular function was observed in patients treated with the IABP at 1-week follow-up angiography. In addition, no reinfarction or reocclusion of the infarct-related artery occurred while patients were being treated with the IABP. These results suggest that the IABP may have a specific role after thrombolytic therapy in treating patients at high risk for reocclusion or at high risk for hemodynamic deterioration because of large infarction or critical stenoses in coronary vessels supplying the noninfarct zone.