Applications of monitoring platelet glycoprotein IIb/IIIa antagonism and low molecular weight heparins in cardiovascular medicine

With the addition of more potent antiplatelet and antithrombin therapies to the armamentarium of the treatment of acute coronary syndromes and percutaneous coronary interventions, monitoring these therapies has become an important interest. Current and evolving technologies to monitor the extent of inhibition of platelet aggregation and activity of factor Xa caused by IIb/IIIa antagonists and low-molecular-weight heparin, respectively, will be covered in this overview. An underlying question to be considered is whether the results generated from monitoring will effect a change that will improve the efficacy (prevent thrombotic events) or reduce adverse events (bleeding) from these potent therapies.

A critical appraisal of platelet glycoprotein IIb/IIIa inhibition

Despite the success of abciximab in preventing ischemic events after percutaneous coronary interventions, attempts to develop intravenous, small-molecule glycoprotein IIb/IIIa antagonists and diversify the clinical indications for these agents have produced varied results. The 30-day ischemic event reduction in the percutaneous coronary intervention trials has ranged by over three-fold (16% to 56%) and is greater among the acute coronary syndrome trials. The phase III trials exploring the role of oral glycoprotein IIb/IIIa inhibition have been consistently disappointing, with evolving evidence of increased mortality. Mechanisms contributing to these heterogeneous results may include normal variation in platelet or receptor number, differences in receptor activity, interpatient variation in pharmacological dose-response and the possibility of prothrombotic or nonglycoprotein IIb/IIIa effects. Plausibility of "suboptimal" effect is suggested by several recent studies. Trials investigating the role of intravenous small-molecule IIb/IIIa antagonists highlight the importance of effective dosing. The increase in bleeding and mortality observed in the oral glycoprotein IIb/IIIa studies indicate the consequences of suboptimal dosing on safety on one hand, while raising the possibility of important prothrombotic, counterregulatory or other sudden cardiac events. This article will undertake a review of the relevant platelet biology, discuss the mechanisms that may contribute to suboptimal antiplatelet efficacy with these agents and examine insights from the clinical trials supporting these concepts.

Facilitation of early percutaneous coronary intervention after reteplase with or without abciximab in acute myocardial infarction: results from the SPEED (GUSTO-4 Pilot) Trial

OBJECTIVES

We examined the utility of early percutaneous coronary intervention (PCI) in a trial that encouraged its use after thrombolysis and glycoprotein IIb/IIIa inhibition for acute myocardial infarction (MI).

BACKGROUND

Early PCI has shown no benefit when performed early after thrombolysis alone.

METHODS

We studied 323 patients (61%) who underwent PCI with planned initial angiography, at a median 63 min after reperfusion therapy began. A blinded core laboratory reviewed cineangiograms. Ischemic events, bleeding, angiographic results, and clinical outcomes were compared between early PCI and no-PCI patients (n = 162), between patients with Thrombolysis in Myocardial Infarction (TIMI) flow grade 0 or 1 before PCI versus flow grade 2 or 3, and among three treatment regimens.

RESULTS

Early PCI patients showed a procedural success (<50% residual stenosis and TIMI flow grade 3) rate of 88% and a 30-day composite incidence of death, reinfarction, or urgent revascularization of 5.6%. These patients had fewer ischemic events and bleeding complications (15%) than did patients not undergoing early PCI (30%, p = 0.001). Early PCI was used more often in patients with initial TIMI flow grade 0 or 1 versus flow grade 2 or 3 (83% vs. 60%, p < 0.0001). Patients receiving abciximab with reduced-dose reteplase (5 U double bolus) showed an 86% incidence of TIMI grade 3 flow at approximately 90 min and a trend toward improved outcomes.

CONCLUSIONS

In this analysis, early PCI facilitated by a combination of abciximab and reduced-dose reteplase was safe and effective. This approach has several advantages for acute MI patients, which should be confirmed in a dedicated, randomized trial.

Influence of diabetes mellitus on clinical outcomes across the spectrum of acute coronary syndromes. Findings from the GUSTO-IIb study. GUSTO IIb Investigators

AIMS

We examined the characteristics, outcomes, and effects of hirudin vs heparin treatment of diabetic patients across the spectrum of acute coronary syndromes.

METHODS AND RESULTS

We studied the 12,142 patients enrolled in the randomized GUSTO-IIb study. Diabetic patients (n=2175) were older, more often female, more often had prior cardiovascular disease, hypertension, and hyperlipidaemia, and less often were current smokers. Diabetic patients had a higher overall incidence of death or (re)infarction at 30 days (13.1% vs 8.5%, P=0.0001), whether they presented with ST-segment elevation (13.9% vs 9.9%, P=0.0017) or not (12.8% vs 7.8%, P=0.0001), and at 6 months (18.8% vs 11.4%, P=0.0001). Among diabetic patients, hirudin was associated with a tendency toward a lower risk of death or (re)infarction at 30 days (12.2% vs 13.9% with heparin) and 6 months (17.8% vs 20.2%). Diabetic patients had more major bleeding, stroke, heart failure, shock, atrioventricular block, and atrial arrhythmias, but no increased risk for ocular bleeding.

CONCLUSIONS

Diabetic patients with acute coronary syndromes had worse 30-day and 6-month outcomes, particularly those without ST-segment elevation. The statistically non-significant trend toward improved outcomes with hirudin was similar among patients with and without diabetes, with a greater point estimate for the absolute difference in patients with diabetes.

A direct comparison of tirofiban and abciximab during percutaneous coronary revascularization and stent placement: rationale and design of the TARGET study

BACKGROUND

Trials testing intravenous platelet glycoprotein IIb/IIIa antagonists in the setting of percutaneous coronary revascularization and empirically during acute coronary syndromes have consistently demonstrated a reduction in ischemic events. These trials, however, have varied regarding patient population, type, duration and timing of IIb/IIIa therapy, adjunct therapies, and methods for collection and adjudication of end points. All trials were placebo-controlled, and none involved a direct comparison of IIb/IIIa inhibitors. Whether these agents produce a similar clinical outcome in the contemporary practice of coronary interventions is uncertain.

METHODS AND RESULTS

To evaluate the efficacy of tirofiban in patients undergoing percutaneous revascularization with stent placement, a randomized, multicenter, double-blind, double-dummy, abciximab-controlled study is currently underway. All patients will receive preprocedural clopidogrel, weight-adjusted heparin, and aspirin. In 18 countries, 4750 patients undergoing nonemergency percutaneous coronary revascularization will be studied. The primary end point will be the composite 30-day occurrence of death, myocardial infarction, or urgent target vessel revascularization. Secondary end points will include 6-month death, myocardial infarction, or any myocardial revascularization and 1-year death.

CONCLUSION

This is the first large-scale, head-to-head comparison of 2 established IIb/IIIa inhibitors in interventional cardiology. Enrollment is expected to be complete by mid-2000.

Unexpected mortality reduction with abciximab for in-stent restenosis

Treatment of in-stent restenosis is generally considered low risk, and it is not clear if adjunctive use of abciximab is beneficial in this low-risk population. We determined the effect of adjunctive abciximab during percutaneous coronary intervention (PCI) for treatment of in-stent restenosis. Two hundred and ninety-three patients with in-stent restenosis underwent PCI at the Cleveland Clinic between January 1996 and December 1998. Patients undergoing directional atherectomy, laser treatment and brachytherapy were excluded (9 patients). Of the remaining 284, seventy-nine patients received abciximab during PCI and 205 were treated without abciximab. The groups were similar with respect to age, gender, left ventricular function, number of vessels involved, history of prior coronary artery bypass grafting and unstable symptoms at presentation. There were more diabetics, hypertensives, and patients with elevated cholesterol in the abciximab-treated group. At 1-year follow-up, there was a significantly lower incidence of myocardial infarction (2.5% versus 5.3%; p < 0.05) and lower mortality (1.2% versus 5.8%; p < 0.01) in the abciximab-treated group. There was no difference in the incidence of revascularization. The findings of a lowered mortality and myocardial infarction rate with abciximab warrants further prospective study in patients with in-stent restenosis.

Survival outcomes 1 year after reperfusion therapy with either alteplase or reteplase for acute myocardial infarction: results from the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO) III Trial

BACKGROUND

New recombinant plasminogen activators have been developed to simulate the fibrinolytic action of the physiological serine protease tissue plasminogen activator (alteplase, t-PA), and have prolonged half-life features permitting bolus administration. One such activator, reteplase (r-PA), was compared with t-PA in the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO)-III Trial.

METHODS AND RESULTS

At 1-year follow-up, survival status was ascertained in 97.4% of the 15 059 patients enrolled in the GUSTO-III trial. At 1 year, the mortality rate for the t-PA-assigned group was 11.06%, and for r-PA it was 11.20% (P:=0. 77). The absolute mortality difference of 0.14% has 95% CIs of -1. 21% to 0.93%. There were no significant differences in outcome by intention-to-treat for the 2 different plasminogen activators in the prespecified groups (age, infarct location, time-to-treatment). The absolute difference in mortality rates between t-PA and r-PA progressively narrowed over the predetermined observation times after random assignment; it was 0.31% at 24 hours, 0.26% at 7 days, 0.23% at 30 days, and 0.14% at 1 year. Of note, mortality rate in the trial between 30 days and 1 year in 13 883 patients was 4.02% and did not differ between the treatment groups. However, this mortality rate was substantially greater than in GUSTO-I, in which mortality rate for t-PA versus streptokinase between 30 days and 1-year was 2.97% (heart rate 1.36, 95% CI 1.23, 1.50, P:<0.001).

CONCLUSIONS

The r-PA and t-PA strategies yielded similar survival outcomes after 30 days in this trial. The increase in mortality rate during extended follow-up compared with previous trials may reflect higher-risk patients and highlights the need for improved secondary prevention strategies.

Pronounced benefit of coronary stenting and adjunctive platelet glycoprotein IIb/IIIa inhibition in complex atherosclerotic lesions

BACKGROUND

Previous trials testing stents compared with balloon angioplasty excluded patients with complex lesions and did not assess the effect of adjunctive platelet IIb/IIIa inhibition. This analysis sought to assess the effect of stenting and abciximab specifically for patients with complex lesions.

METHODS AND RESULTS

Patients with complex lesions (long, tandem, severely calcified, restenotic, thrombotic, or ostial; total occlusions; bifurcations; saphenous vein grafts; and multivessel interventions) from the Evaluation of PTCA to Improve Long-Term Outcome by c7E3 GP IIb/IIIa Receptor Blockade (EPILOG) and the Evaluation of Platelet IIb/IIIa Inhibitor for Stenting (EPISTENT) trials were included in the analysis. The 1-year combined death or myocardial infarction rates in the 4 treatment groups were as follows: balloon angioplasty/placebo, 14.2%; stent/placebo, 15.8%; balloon angioplasty/abciximab, 7.6%; and stent/abciximab, 8.0% (P<0.001). Death rates were 3.2%, 3.1%, 2.1%, and 0.5%, respectively (P=0.03). The incidence of target vessel revascularization at 1 year was 30.5%, 18.0%, 24.4%, and 19.7% in the 4 groups, respectively (P<0.001). After adjustment for baseline differences, multivariate analysis demonstrated that the rate of death or myocardial infarction was independently reduced by balloon angioplasty/abciximab (hazard ratio, 0.51; P<0.001) and stent/abciximab (hazard ratio, 0.60; P=0.02) but was not affected by the use of stents alone. Conversely, target vessel revascularization was reduced by stent/placebo (hazard ratio, 0.53; P<0.001), stent/abciximab (hazard ratio, 0.58; P<0.001), and balloon angioplasty/abciximab (hazard ratio, 0.74; P=0.006) compared with balloon angioplasty/placebo, respectively.

CONCLUSIONS

The combination of stenting and abciximab during percutaneous coronary interventions for patients with angiographically complex lesions confers additive long-term benefit with respect to death, myocardial infarction, and target vessel revascularization.

Achieving tissue-level perfusion in the setting of acute myocardial infarction

Treatment for ST-elevation myocardial infarction (MI) has advanced rapidly in the last few years with improvements in early fibrinolytic therapy, primary percutaneous revascularization, and use of potent platelet glycoprotein IIb/IIIa inhibitors. It is now obvious that establishing epicardial patency after myocardial infarction is not synonymous with tissue-level perfusion. Techniques and therapies are now available that measure true tissue-level perfusion and that may improve tissue-level perfusion after myocardial infarction.

Patient-specific dosing of IIb/IIIa antagonists during acute coronary syndromes: rationale and design of the PARAGON B study. The PARAGON B International Steering Committee

BACKGROUND

Acute coronary syndromes, the leading cause of hospitalizations among adults, are frequently the sequelae of atherothrombotic events associated with coronary arterial plaque rupture. Beyond the usual antithrombotic therapies (aspirin and heparin), potent antiplatelet agents, glycoprotein IIb/IIIa receptor antagonists, have been shown to improve patient outcome. Lamifiban is a short-acting, renally excreted IIb/IIIa antagonist that was found in post hoc analyses of the Platelet IIb/IIIa Antagonism for the Reduction of Acute Coronary Syndrome Events in a Global Organization Network (PARAGON A) study to reduce the 30-day incidence of death or myocardial infarction by 40% when plasma concentrations of 18 to 42 ng/mL were achieved.

METHODS AND RESULTS

To determine if lamifiban, dosed according to creatinine clearance, could decrease the rates of death, myocardial infarction, or refractory ischemia, a randomized, double-blind, placebo-controlled trial was undertaken. In 26 countries, 5228 patients seen within 12 hours of symptom onset of a non-ST-elevation acute coronary syndrome were randomly assigned to placebo or lamifiban bolus and infusion.

CONCLUSION

The plasma concentration of small-molecule IIb/IIIa inhibitors is strongly influenced by renal function, and renal-specific dosing of these agents may improve outcome among patients with acute coronary syndromes. The PARAGON B trial is testing this hypothesis.

Predictors of death and reinfarction at 30 days after primary angioplasty: the GUSTO IIb and RAPPORT trials

BACKGROUND

Thirty-day death among recipients of fibrinolytic therapy for acute myocardial infarction (MI) is tightly correlated with easily obtainable key demographic and clinical parameters such as age, blood pressure, heart rate, and infarct location. Similar data for primary angioplasty are not available.

METHODS AND RESULTS

Data from 2 large, contemporary, primary angioplasty trials were formally combined and analyzed with respect to death and death/repeat MI at 30 days through the use of multivariate logistic regression models. The 1048 patients had a median age of 62 years, and 26% were women. Thirty-eight percent had an anterior infarction. The patients underwent angioplasty at a median delay from symptom onset of 3.8 hours. Death was independently predicted by increasing age (adjusted odds ratio [OR] per decade 2.32, 95% confidence interval [CI] 1.60 to 3.42), whereas a history of smoking (OR 0.29, CI 0.13 to 0.64), Thrombolysis in Myocardial Infarction (TIMI) flow grade 3 after angioplasty (OR vs TIMI <3 0.21, CI 0.10 to 0.45) and higher systolic blood pressure (OR per 10 mm Hg 0.73, CI 0.62 to 0. 87) were associated with lower mortality rates. Death or repeat MI was independently associated with increasing age (OR per decade 1.40, CI 1.13 to 1.76) and anterior location of the index MI (OR 1.89, CI 1.12 to 3.20). TIMI grade 3 flow (OR vs TIMI <3 0.40, CI 0.23 to 0. 68) and higher systolic blood pressure (OR per 10 mm Hg 0.79, CI 0. 71 to 0.89) were associated with a lower incidence of death/repeat MI. Time to angioplasty, heart rate, extent of coronary artery disease, participation in 1 of the 2 trials, and all common coronary risk factors did not significantly predict outcome.

CONCLUSIONS

Death and reinfarction after primary angioplasty are predominantly predicted by age, hemodynamic instability, and the attainment of TIMI 3 flow in the infarct artery.

Platelet glycoprotein IIb/IIIa receptor antagonists and their use in elderly patients

With increasing age of the general population, cardiovascular diseases are becoming a greater health burden. Coronary artery disease remains a major cause of morbidity and mortality worldwide. Among the various pathophysiological processes, platelets play a pre-eminent role. With the identification of the glycoprotein (GP) IIb/IIIa receptor as the final common pathway for platelet aggregation, potent antiplatelet agents have been developed. These GP IIb/IIIa antagonists have been shown to be effective in improving outcomes among patients undergoing percutaneous coronary interventions and for the treatment of acute coronary syndromes. By pooling the results of several large-scale trials, these benefits have been found to extend to the elderly population. Among 7860 patients undergoing percutaneous coronary intervention, the occurrence of death or myocardial infarction at 30 days was reduced from 10.0 to 5.9% (odds ratio 0.56; 95% confidence level, 0.37 to 0.83) with abciximab compared with placebo, in those >70 years of age. Importantly, this benefit was achieved without an increase in major bleeding complications. Similarly favourable trends were also observed among elderly patients treated with tirofiban or eptifibatide for acute coronary syndromes. As such, GP IIb/IIIa antagonists are effective in preventing ischaemic complications and can be safely administered to elderly patients.

Platelet glycoprotein IIb/IIIa receptor antagonists

The molecular understanding of platelet function, together with an appreciation of the role of platelet thrombus in the pathogenesis of acute coronary syndromes (ACS) and abrupt vessel closure following coronary intervention, lead to the development of the class of agents now referred to as platelet glycoprotein IIb/IIIa (GP IIb/IIIa) inhibitors. Currently three parenteral GP IIb/IIIa inhibitors are licensed for use in patients undergoing coronary intervention or as empirical therapy in non-ST elevation ACS (unstable angina and non-Q wave myocardial infarction). Clinical trials using these agents in patients undergoing coronary interventions have demonstrated a consistent reduction in ischaemic end points at 30 days that is sustained during long-term follow-up. Similar benefits have been found in patients with ACS who are managed medically or who proceed to revacularization. Studies using prolonged platelet inhibition using oral GP IIb/IIIa inhibitors in patients following coronary intervention or with ACS have produced disappointing results. Further investigation with existing and newer oral agents are ongoing. The use of GP IIb/IIIa inhibitors in combination with fibrinolytic agents for optimal reperfusion in patients with acute ST-elevation myocardial infarction (MI) is an active area of interest. Angiographic outcomes with this approach have been encouraging and clinical outcome data are awaited. Beyond efficacy, GP IIb/IIIa inhibitors have proven to be safe for clinical use. Haemorrhagic complications and thrombocytopenia are the most common adverse events, though infrequent. Unresolved issues regarding drug dosing, monitoring of effect, duration of therapy, head-to-head comparisons of agents, and use of adjunctive therapies are the subject of ongoing studies.

Insights into the pathophysiology of atherosclerosis and prognosis of black Americans with acute coronary syndromes

BACKGROUND

Disparities in prognosis for black and white patients with coronary heart disease have been widely reported. For several reasons it is unclear to what extent biologic factors contribute to these differences.

METHODS

The current medical literature regarding the pathophysiologic characteristics of cardiovascular disease is reviewed with emphasis on how racially mediated biologic differences may affect the manifestation, treatment, and prognosis of patients with coronary heart disease, particularly patients with acute coronary syndromes.

RESULTS

Black patients with coronary heart disease have a higher prevalence of ischemic heart disease risk factors, including hypertension, left ventricular hypertrophy, diabetes, and tobacco use. Other factors related to atherosclerosis, vascular reactivity, and thrombolysis that quantitatively and functionally differ among racial groups are identified. Prospective, randomized trials comparing outcomes among patients with acute coronary syndromes have included only a fraction of the available black population, although they reveal a similar short-term mortality rate for black and white patients. Several factors, including enhanced fibrinolysis among black patients with acute myocardial infarction, may in part counterbalance better understood and more prevalent comorbidities to equalize short-term (30-day) survival. All-cause, long-term (1-year) mortality appears worse for black patients compared with white patients with similar cardiovascular risk profiles.

CONCLUSION

As racially mediated biologic differences between black and white patients become better understood, targeted interventions to prevent coronary heart disease and treat acute coronary syndromes in black patients can be developed.

Racial differences in the management of unstable angina: results from the multicenter GUARANTEE registry

BACKGROUND

Prior studies, usually conducted with the use of insurance databases, have shown differences in the use of cardiac procedures between black patients and white patients hospitalized with various types of coronary artery disease. However, few data are available in prospectively collected cohorts of patients with unstable angina or on the use of appropriate medications or interventions.

METHODS AND RESULTS

We evaluated 2948 consecutive patients with unstable angina admitted to 35 hospitals across the United States in 1996, comparing nonwhite and white patients. Seventy-seven percent of patients were white, 14% were black, 4% were Hispanic, 1% were Asian, and 3% were other or unknown race. Differences were seen in coronary risk profile, with a higher incidence of hypertension and diabetes mellitus in nonwhites. Cardiac catheterization was performed less often in nonwhites compared with whites (36% vs 53%, P =.001). Even in patients meeting the criteria for appropriate catheterization in the Agency for Health Care Policy Research unstable angina guidelines, fewer nonwhites underwent catheterization (44% vs 61%, P =.001), but among these, fewer nonwhites had significant coronary stenosis (72% vs 90%, P =.001). However, among patients catheterized who had indications for revascularization, angioplasty and coronary artery bypass grafting were performed equally often in nonwhites and whites.

CONCLUSIONS

Current guidelines would recommend more aggressive use of cardiac catheterization for nonwhite patients. However, our findings suggest that racial differences may need to be included in the diagnostic and interventional algorithms.

Differences between men and women in the management of unstable angina pectoris (The GUARANTEE Registry). The GUARANTEE Investigators

Few data are available in prospectively collected cohorts of patients with unstable angina pectoris or on the use of appropriate medications or interventions. Accordingly, we evaluated 2,948 consecutive patients with unstable angina admitted to 35 hospitals in the United States in 1996, and comparing men and women (39% of the patients were women). Differences were seen in coronary risk profiles with a higher incidence of systemic hypertension, diabetes mellitus, and a family history of coronary disease in women. Women were less likely to receive Agency for Health Care Policy Research (AHCPR) recommended pharmacologic treatment than men. Cardiac catheterization, coronary angioplasty, and bypass was performed less often in women compared with men (44% vs. 53%, p = 0.002; 12% vs. 18%, p = 0.02; 7% vs. 10%, p = 0.001, respectively). At catheterization, women were more likely to have no significant coronary artery disease (25% vs. 14%, p = 0.001). Although fewer women than men fulfilled the AHCPR criteria for cardiac catheterization (54% vs. 64%, p = 0.001), a similar rate of men and women with positive criteria underwent catheterization and angioplasty. However, fewer women with positive criteria underwent bypass surgery (36% vs. 46%, p = 0.03). More men "ruled-in" for a myocardial infarction at admission (13% vs. 8%, p = 0.001), but there was no difference in recurrent angina, in-hospital myocardial infarction, or death. Despite different epidemiologic profiles and less evidence of coronary artery disease by noninvasive and invasive tests, women and men had similar outcomes.

Attainment and maintenance of platelet inhibition through standard dosing of abciximab in diabetic and nondiabetic patients undergoing percutaneous coronary intervention

BACKGROUND

Although the effectiveness of abciximab (c7E3 Fab; ReoPro) in large populations of patients undergoing a percutaneous coronary intervention has been consistently proved in clinical trials, it is unknown whether all patients achieve and maintain target inhibition during treatment. Diabetic patients in particular are a subgroup of patients with known underlying platelet abnormalities whose long-term response to abciximab has been shown to vary from that of nondiabetic patients.

METHODS AND RESULTS

Forty-nine diabetic and 51 nondiabetic patients who received adjunctive abciximab therapy during percutaneous coronary interventions were evaluated prospectively. The degree of platelet function inhibition was determined immediately after the abciximab bolus, 8 hours after the bolus (during the 12-hour abciximab infusion), and the next morning (13 to 26 hours after the bolus) with the use of a rapid platelet function assay (Accumetrics). After the abciximab bolus, platelet function was inhibited by 95+/-4% (mean+/-SD). By 8 hours, the average percent inhibition had decreased to 88+/-9%, with 13% of patients with <80% inhibition. The next morning (mean 19 hours after the bolus), mean inhibition was 71+/-14%. A difference was not found between diabetics and nondiabetics, nor was any physiological parameter found to be predictive of the response to abciximab.

CONCLUSIONS

Although the majority of patients achieve and maintain >/= 80% platelet inhibition during the 12-hour infusion with standard-dose abciximab, there is substantial variability among patients. Diabetic status does not appear to influence this variability.

Aspirin, ticlopidine, and clopidogrel in acute coronary syndromes: underused treatments could save thousands of lives

Aspirin is the cornerstone of therapy for unstable angina and acute myocardial infarction and the foundation on which other therapies are added, both in the short term and the long term. Yet, despite clear data, aspirin is woefully underused or is often used late. Prompt administration of aspirin could save thousands of lives each year. Ticlopidine and clopidogrel have a synergistic effect when used with aspirin, and can also have a role in treating patients who are aspirin-resistant or have diffuse atherosclerosis.

Platelet glycoprotein IIb/IIIa inhibition in acute coronary syndromes

Acute coronary syndromes are a leading cause of hospitalization in industrialized countries. Current antithrombotic therapy focuses on relatively weak antiplatelet agents and heparin. The advent of inhibitors of the platelet glycoprotein IIb/IIIa receptor, the final common pathway for aggregation, provides a new therapeutic modality. Clinical trials with a total of more than 18,000 patients have clearly shown the benefits of intravenous IIb/IIIa blockade. Overall, at 30 days, 13 fewer deaths or myocardial infarctions occurred for every 1000 patients treated in these trials. This favorable outcome was extended to 6 months, resulting in 16 fewer such events per 1000 patients treated. Importantly, these benefits were not accompanied by an excessive occurrence in bleeding complications or thrombocytopenia. To further improve outcomes in this high-risk group of patients, strategies pertaining to prolonged periods of vessel passivation with oral formulations and early or delayed invasive approaches are being studied.

Complementary clinical benefits of coronary-artery stenting and blockade of platelet glycoprotein IIb/IIIa receptors. Evaluation of Platelet IIb/IIIa Inhibition in Stenting Investigators

BACKGROUND

Inhibition of the platelet glycoprotein IIb/IIIa receptor with the monoclonal-antibody fragment abciximab reduces the acute ischemic complications associated with percutaneous coronary revascularization, whereas coronary-stent implantation reduces restenosis. We conducted a trial to determine the efficacy of abciximab and stent implantation in improving long-term outcome.

METHODS

A total of 2399 patients were randomly assigned to stent implantation and placebo, stent implantation and abciximab, or balloon angioplasty and abciximab. The patients were followed for six months.

RESULTS

At six months, the incidence of the composite end point of death or myocardial infarction was 11.4 percent in the group that received a stent and placebo, as compared with 5.6 percent in the group that received a stent and abciximab (hazard ratio, 0.47; 95 percent confidence interval, 0.33 to 0.68; P<0.001) and 7.8 percent in the group assigned to balloon angioplasty and abciximab (hazard ratio, 0.67; 95 percent confidence interval, 0.49 to 0.92; P=0.01). The hazard ratio for stenting plus abciximab as compared with angioplasty plus abciximab was 0.70 (95 percent confidence interval, 0.48 to 1.04; P=0.07). The rate of repeated revascularization of the target vessel was 10.6 percent in the stent-plus-placebo group, as compared with 8.7 percent in the stent-plus-abciximab group (hazard ratio, 0.82; 95 percent confidence interval, 0.59 to 1.13; P=0.22) and 15.4 percent in the angioplasty-plus-abciximab group (hazard ratio, 1.49; 95 percent confidence interval, 1.13 to 1.97; P=0.005). The hazard ratio for stenting plus abciximab as compared with angioplasty plus abciximab was 0.55 (95 percent confidence interval, 0.41 to 0.74; P<0.001). Among patients with diabetes, the combination of abciximab and stenting was associated with a lower rate of repeated target-vessel revascularization (8.1 percent) than was stenting and placebo (16.6 percent, P=0.02) or angioplasty and abciximab (18.4 percent, P=0.008).

CONCLUSIONS

For coronary revascularization, abciximab and stent implantation confer complementary long-term clinical benefits.

Invasive vs conservative management of non-Q-wave myocardial infarction

In the Veterans Affairs Non-Q-Wave Infarction Strategies in Hospital (VANQWISH) trial, most patients with non-Q-wave myocardial infarction (MI) fared no better with early invasive management (i.e., diagnostic angiography within 2 to 3 days, followed by revascularization if indicated) than with a more conservative approach (i.e., radionuclide ventriculography and thallium stress testing as initial diagnostic tests). These results should not be construed to diminish the value of early diagnostic angiography, which in patients with non-Q-wave MI provides essential information for determining the need, timing, and method of revascularization. Until more information is available that incorporates contemporary practices and outcomes in patients with non-Q-wave MI, early coronary angiography should remain an acceptable method of risk stratification and should be followed by appropriate medical therapy or revascularization.

Clinical outcomes of therapeutic agents that block the platelet glycoprotein IIb/IIIa integrin in ischemic heart disease

BACKGROUND

Several platelet glycoprotein (GP) IIb/IIIa receptor antagonists have been evaluated in clinical trials. We conducted a systematic overview (meta-analysis) to assess the effect of these compounds on death, myocardial infarction (MI), and revascularization.

METHODS AND RESULTS

ORs were calculated for 16 randomized, controlled trials of GP IIb/IIIa inhibitors. An empirical Bayesian random-effects model combined the outcomes of 32 135 patients. There was a significant mortality reduction by GP IIb/IIIa inhibitors at 48 to 96 hours, with an OR of 0.70 (95% CI, 0. 51 to 0.96; P<0.03), equivalent to a reduction of 1 death per 1000 patients treated. Mortality benefits at 30 days (OR, 0.87; 95% CI, 0. 74 to 1.02; P=0.08) and 6 months (OR, 0.97; 95% CI, 0.86 to 1.10; P=0.67) were not statistically significant. For the combined end point of death or MI, there was a highly significant (P<0.001) benefit for GP IIb/IIIa inhibitors at each time point. The 30-day OR was 0.76 (95% CI, 0.66 to 0.87), or 20 fewer events per 1000 patients treated. For the composite end point of death, MI, or revascularization, there was also a highly significant (P<0.001) benefit for GP IIb/IIIa inhibitors. At 30 days, the OR was 0.77 (95% CI, 0.68 to 0.86), or 30 fewer events per 1000 patients treated. The risk differences for death, death or MI, and composite outcomes were similar at 6 months, indicating a sustained absolute improvement. Similar benefit was seen when trials were subgrouped by therapeutic indication (percutaneous intervention versus acute coronary syndromes).

CONCLUSIONS

Application of this new therapeutic class to clinical practice promises substantial benefit for both indications.

The duration of pretreatment with ticlopidine prior to stenting is associated with the risk of procedure-related non-Q-wave myocardial infarctions

OBJECTIVES

This study sought to determine whether the duration of pretreatment with the adenosine diphosphate receptor antagonist ticlopidine prior to intracoronary stenting is associated with the incidence of procedure-related non-Q-wave myocardial infarctions (MIs).

BACKGROUND

Dual antiplatelet therapy with ticlopidine and aspirin is routinely used with stenting, although ticlopidine is commonly not begun until the day of the procedure. Periprocedural MIs are at least partially platelet-dependent events. As the maximal platelet inhibitory effects of this drug take 2 to 3 days to be realized, we hypothesized that longer treatment prior to stenting would be associated with lower rates of procedure-related MIs.

METHODS

We reviewed outcomes in 175 consecutive patients treated with ticlopidine prior to stenting at the Cleveland Clinic Foundation. Those patients with an elevation in creatine kinase above our laboratory normal (>210 IU/L) with > or =4% MB fraction on routine evaluation were defined as having a non-Q-wave MI. RESULTS. There were 28 patients (16%) who had a non-Q-wave MI. Longer duration of ticlopidine pretreatment was strongly associated with a lower incidence of procedure-related non-Q-wave MIs (duration of pretreatment <1 day, 29% had MI; 1 to 2 days, 14%; > or =3 days, 5%; chi-square for trend=9.6; p=0.002). Ticlopidine pretreatment of > or =3 days was associated with a significant reduction in the risk of non-Q-wave MI (unadjusted odds ratio 0.18, 95% confidence interval=0.04 to 0.78, p=0.01) compared with pretreatment of <3 days.

CONCLUSIONS

Among patients undergoing intracoronary stenting, beginning ticlopidine therapy several days prior to the procedure is associated with a reduced risk of procedural non-Q-wave MIs.

Randomized, placebo-controlled trial of platelet glycoprotein IIb/IIIa blockade with primary angioplasty for acute myocardial infarction. ReoPro and Primary PTCA Organization and Randomized Trial (RAPPORT) Investigators

BACKGROUND

The benefit of catheter-based reperfusion for acute myocardial infarction (MI) is limited by a 5% to 15% incidence of in-hospital major ischemic events, usually caused by infarct artery reocclusion, and a 20% to 40% need for repeat percutaneous or surgical revascularization. Platelets play a key role in the process of early infarct artery reocclusion, but inhibition of aggregation via the glycoprotein IIb/IIIa receptor has not been prospectively evaluated in the setting of acute MI.

METHODS AND RESULTS

Patients with acute MI of <12 hours' duration were randomized, on a double-blind basis, to placebo or abciximab if they were deemed candidates for primary PTCA. The primary efficacy end point was death, reinfarction, or any (urgent or elective) target vessel revascularization (TVR) at 6 months by intention-to-treat (ITT) analysis. Other key prespecified end points were early (7 and 30 days) death, reinfarction, or urgent TVR. The baseline clinical and angiographic variables of the 483 (242 placebo and 241 abciximab) patients were balanced. There was no difference in the incidence of the primary 6-month end point (ITT analysis) in the 2 groups (28.1% and 28.2%, P=0.97, of the placebo and abciximab patients, respectively). However, abciximab significantly reduced the incidence of death, reinfarction, or urgent TVR at all time points assessed (9.9% versus 3.3%, P=0.003, at 7 days; 11.2% versus 5.8%, P=0.03, at 30 days; and 17.8% versus 11.6%, P=0.05, at 6 months). Analysis by actual treatment with PTCA and study drug demonstrated a considerable effect of abciximab with respect to death or reinfarction: 4.7% versus 1.4%, P=0.047, at 7 days; 5.8% versus 3.2%, P=0.20, at 30 days; and 12.0% versus 6.9%, P=0.07, at 6 months. The need for unplanned, "bail-out" stenting was reduced by 42% in the abciximab group (20.4% versus 11.9%, P=0.008). Major bleeding occurred significantly more frequently in the abciximab group (16.6% versus 9.5%, P=0.02), mostly at the arterial access site. There was no intracranial hemorrhage in either group.

CONCLUSIONS

Aggressive platelet inhibition with abciximab during primary PTCA for acute MI yielded a substantial reduction in the acute (30-day) phase for death, reinfarction, and urgent target vessel revascularization. However, the bleeding rates were excessive, and the 6-month primary end point, which included elective revascularization, was not favorably affected.

Influence of insurance type on the use of procedures, medications and hospital outcome in patients with unstable angina: results from the GUARANTEE Registry. Global Unstable Angina Registry and Treatment Evaluation

OBJECTIVES

The purpose of this study was to investigate whether or not there is an association between managed care insurance and the delivery and outcome of care in patients presenting with unstable angina.

BACKGROUND

The proportion of U.S. patients with managed care health insurance is increasing. This may be associated with recent improvements in the control of health care costs. It is unknown whether or not there is a difference in process of care in angina patients presenting with managed care versus fee-for-service health insurance.

METHODS

We compared baseline characteristics, process and outcome of care in 636 patients with managed care insurance (MC) and 1,404 patients with fee-for-service (FFS) insurance who presented with unstable angina to 35 hospitals participating in the global Unstable Angina Registry and Treatment Evaluation (GUARANTEE) Registry.

RESULTS

Although, there was little difference in baseline characteristics and hospital treatments between cohorts, MC patients were more likely to be discharged on guideline-recommended medications (aspirin and beta-adrenergic blocking agents). In addition, FFS patients were more likely to undergo cardiac catheterization (odds ratio = 1.25 95% confidence interval = 1.1 to 1.5), but not revascularization during the hospitalization. There was no difference in hospital mortality (0.9% versus 1.2% in MC versus FFS; p = 0.60).

CONCLUSIONS

In patients admitted with suspected unstable angina, MC patients are less likely to undergo coronary angiography, but are more likely to be discharged on indicated medications.

Glycoprotein IIb/IIIa receptor antagonists for the treatment of unstable angina

Unstable angina and non-Q-wave myocardial infarction, part of the acute coronary syndromes, are characterized by coronary arterial plaque rupture and endovascular thrombus formation. Plaque rupture leads to exposure of subendothelial components such as collagen and fibronectin, and these substances are known to cause platelet activation, aggregation, and initiation of the coagulation cascade. Aspirin and heparin have been used as therapeutic mainstays for acute coronary syndromes, acting as antiplatelet and antithrombin agents, respectively. Despite treatment with this conventional anticoagulant strategy and antianginal drugs, substantial morbidity and mortality continue to be associated with unstable angina and non-Q-wave myocardial infarction. Specific antagonists of the platelet glycoprotein IIb/IIIa inhibitor have proved effective in substantially reducing ischemic events following percutaneous coronary revascularization, and several trials using these agents in acute coronary syndromes are now completed. Compared to patients receiving standard therapy (aspirin and heparin), platelet IIb/IIIa antagonists have further reduced the incidence of major ischemic events. Ongoing studies are addressing the optimal extent and duration of platelet inhibition in patients with acute coronary syndromes.

Basilar artery rethrombosis: successful treatment with platelet glycoprotein IIB/IIIA receptor inhibitor

We describe the use of abciximab to prevent rethrombosis of the basilar artery after transluminal angioplasty. A 60-year-old patient with vertebral basilar insufficiency and acute occlusion of the basilar artery underwent revascularization with urokinase and angioplasty. Despite the repeated use of urokinase and angioplasty under anticoagulation with heparin, the basilar artery immediately rethrombosed. In a final attempt to prevent rethrombosis, abciximab was administered before the final angioplasty, resulting in a widely patent basilar artery and no rethrombosis.

Influence of diabetes mellitus on clinical outcome in the thrombolytic era of acute myocardial infarction. GUSTO-I Investigators. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries

OBJECTIVES

This study was undertaken to define and better understand the characteristics and outcomes of patients with diabetes treated for acute myocardial infarction with contemporary thrombolysis.

BACKGROUND

Although thrombolysis has substantially improved survival of patients with myocardial infarction, diabetes mellitus remains an independent predictor for a poor prognosis.

METHODS

We characterized the contemporary relation between diabetes and outcome after myocardial infarction treated with thrombolytic agents from a large international cohort. Of 41,021 patients randomized to receive accelerated tissue-type plasminogen activator (t-PA), streptokinase or a combination of both agents in the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries study, there were 5,944 patients with diabetes and 34,888 patients without diabetes.

RESULTS

Patients with diabetes were older and more likely to be female, to present with anterior wall infarction, to receive thrombolysis later and to have triple-vessel coronary artery disease. Mortality at 30 days was highest among diabetic patients treated with insulin (12.5%) compared with non-insulin-treated diabetic (9.7%) and nondiabetic (6.2%) patients (p < 0.001). Mortality was lowest among those with diabetes receiving accelerated t-PA, which is consistent with the results of the overall patient cohort. Although stroke occurred more frequently among diabetic (1.9%) than nondiabetic patients (1.4%, p < 0.001), there was no significant difference in the rates of intracranial hemorrhage. Cardiac failure, shock, atrioventricular block and atrial flutter/ fibrillation were more common among diabetic patients. The proportion of patients undergoing revascularization was similar between patients with and without diabetes, although diabetic patients were more likely to undergo coronary artery bypass graft surgery (10.4% vs. 8.3%). Diabetes remained an independent predictor for mortality at 1-year follow-up (14.5% vs. 8.9%, p < 0.001).

CONCLUSIONS

Diabetes, alone and in association with its comorbidities, portends a substantially worse 30-day and 1-year prognosis for patients with myocardial infarction.

First chronic platelet glycoprotein IIb/IIIa integrin blockade. A randomized, placebo-controlled pilot study of xemilofiban in unstable angina with percutaneous coronary interventions

BACKGROUND

Clinical studies have demonstrated the efficacy of intravenous administration of agents that block platelet glycoprotein IIb/IIIa receptors in the setting of percutaneous coronary revascularization. Although the optimal duration of treatment has not been determined, more prolonged receptor blockade has been associated with increased efficacy. Orally active glycoprotein IIb/IIIa receptor antagonists may be advantageous and required for chronic therapy.

METHODS AND RESULTS

Thirty patients with unstable angina who were undergoing percutaneous coronary interventions were randomized to placebo or Xemilofiban 35 mg orally before and 20 to 25 mg TID for 30 days after angioplasty. Bleeding events, platelet aggregation, and pharmacokinetic and hematologic parameters were assessed during hospitalization and at 2 and 4 weeks after drug initiation. Xemilofiban produced a rapid, sustained, marked inhibition of platelet aggregation. ADP-induced platelet aggregation at 2 hours after the initial dose at 2 and 4 weeks was 15%, 8%, and 11% in the Xemilofiban group compared with 80%, 68%, and 69% in the placebo group. Among 20 patients randomized to Xemilofiban there was 1 death after emergency coronary bypass surgery complicated by severe bleeding diathesis, and 3 patients had major bleeding events. Patients on Xemilofiban for 30 days reported episodes of mild mucocutaneous bleeding.

CONCLUSIONS

Xemilofiban, an orally active glycoprotein IIb/ IIIa receptor inhibitor, produced rapid, sustained, extensive inhibition of platelet aggregation for a period of up to 30 days. At the dose initially tested, however, acute major bleeding and mucocutaneous bleeding during chronic administration were encountered.

Restenosis--an open file

The main procedural drawback to percutaneous coronary angioplasty is restenosis of the treated site within 6 months. Despite advances in equipment, technique, and adjunctive therapies, restenosis has occurred in approximately one-third to one-half of all patients. The biology of restenosis can be divided into plaque persistence and recoil, thrombus formation and transformation, and cellular proliferation and vascular remodeling. Animal models of restenosis have helped to elucidate these mechanisms of restenosis and provide a means to test pharmacologic and mechanical strategies to reduce stenosis recurrence. While numerous agents have been tested in animal models, until recently none has translated into benefit in large-scale clinical trials. Two therapeutic "hopefuls" which have recently emerged in clinical practice are the potent platelet inhibitors, glycoprotein IIb/IIIa receptor antagonists, and intracoronary metallic stents. The IIb/IIIa receptor antagonists target thrombus formation at the angioplasty site, thereby minimizing abrupt vessel closure acutely and neointimal growth chronically, while intracoronary stents safely produce a large coronary arterial lumen acutely and prevent vessel recoil. Separately, these therapeutic strategies have been shown to reduce clinical restenosis 20-30% at 6-month follow-up. With these encouraging results, the future will certainly provide more pharmacologic and mechanical therapies targeting restenosis. With increased understanding of the restenotic process and continued refinement of effective treatments, it may be possible one day to prevent stenosis recurrence.

Subacute stent thrombosis: evolving issues and current concepts

During percutaneous coronary revascularization, intracoronary stents are effective in the treatment of abrupt vessel closure and improvement of suboptimal angioplasty results, and compared to balloon angioplasty, they reduce stenosis recurrence. Opposing these benefits, subacute thrombosis of stents is associated with a substantial increase in periprocedural morbidity and mortality. To review factors associated with stent thrombosis and to study the impact of evolving procedural techniques on the incidence of stent thrombosis, we reviewed all English articles from MEDLINE (1988 to 1995) with key words "stent" and "thrombosis." Stent registry data and recent abstracts from scientific meetings were also reviewed. Factors related to the clinical setting, the lesion, the stent and the procedural technique that affect the risk of stent thrombosis were identified. Sixty clinical studies were reviewed and include 7,914 patients receiving intracoronary stents. Studies were separated into those reporting stents placed emergently or electively without adjunct high-pressure balloon inflations, stents placed in saphenous vein graft conduits, and stents placed with high-pressure balloon inflations but without subsequent oral anticoagulants. Overall, subacute thrombosis was substantially higher in stents placed emergently (10.1%) compared to those placed electively (4.3%). Among contemporary trials employing high-pressure balloon inflations, the rate of stent thrombosis appears markedly lower (1.3%) despite reduced postprocedural anticoagulation. Taken together, these studies suggest factors associated with a heightened risk of stent thrombosis, many of which can be avoided with proper case selection and contemporary techniques.

No association between plasma lipoprotein(a) concentrations and the presence or absence of coronary atherosclerosis in African-Americans

Elevated plasma concentrations of lipoprotein(a) [Lp(a)] are associated with coronary atherosclerosis in Caucasians. Although African-Americans have a higher median plasma Lp(a) concentration than Caucasians, they do not have a greater incidence of coronary atherosclerosis. This study was performed to determine whether the plasma concentration of Lp(a) is associated with coronary atherosclerosis in African-Americans. The fasting plasma concentrations of Lp(a) and lipoproteins were measured in 140 African-American subjects (62 men, 78 women, aged 31 to 80 years) 18 +/- 16 months (mean +/- SD) after they underwent coronary angiography: 72 had angiographically normal coronary arteries and 68 had > 70% luminal diameter narrowing of one or more major epicardial coronary arteries. The groups were similar in age, sex, and other risk factors for atherosclerosis. The subjects with coronary artery disease had higher plasma concentrations of total cholesterol, triglycerides, and VLDL and LDL cholesterol (P = .04) and lower concentrations of HDL cholesterol (P = .0001) than subjects without coronary artery disease, but there was no significant difference in the plasma concentration of Lp(a). The distribution of apolipoprotein(a) alleles by size was also not significantly different between the two groups. These results suggest that the plasma concentration of Lp(a) is not an independent risk factor for coronary artery disease in African-Americans.

Coronary intravascular ultrasound: diagnostic and interventional applications

Recent advances in microelectronic and piezoelectric technology have permitted development of miniaturized ultrasound devices capable of real-time tomographic intravascular imaging. Initial studies have successfully employed intravascular ultrasound to augment angiography in both diagnostic and therapeutic catheterization. The cross-sectional perspective of intravascular ultrasound appears to be ideally suited for precision measurements of luminal diameter and cross-sectional area. In addition, ultrasound improves assessment of problem lesions such as ostial stenoses or disease at bifurcations. Intravascular imaging provides unique, detailed cross-sectional images of the arterial wall not previously obtainable in vivo by any other technique and is more sensitive than angiography in detecting atherosclerosis. Intravascular ultrasound images of atherosclerotic wall abnormalities have the potential to augment greatly the understanding of the anatomy and pathophysiology of coronary disease. For interventional applications, ultrasound analysis of lesion characteristics offers many potential advantages. Evaluation of the normal reference segment used for device sizing constitutes an important emerging application for intravascular imaging. After the procedure, intravascular ultrasound often yields smaller luminal size measurements than angiography and greater of stenosis. These differences probably reflect augmentation of the apparent angiographic diameter by extraluminal contrast within cracks, fissures or dissection planes. New ultrasound instruments under development combine an imaging transducer with an interventional device, permitting on-line guidance during the procedure. Although the clinical value of routine ultrasound imaging before or after mechanical revascularization has not been tested by randomized trials, it seems likely that this new imaging modality will provide valuable insights into diverse phenomena such as abrupt occlusion and restenosis. Accordingly, we anticipate a continuing role for this modality in cardiovascular interventional therapy.

Effect of platelet glycoprotein IIb/IIIa integrin blockade on activated clotting time during percutaneous transluminal coronary angioplasty or directional atherectomy (the EPIC trial). Evaluation of c7E3 Fab in the Prevention of Ischemic Complications trial

The activated clotting time (ACT) has been used during percutaneous transluminal coronary angioplasty (PTCA) to monitor the extent of thrombin inhibition and anti-coagulation from heparin in an attempt to minimize untoward thrombotic events and hemorrhagic complications. With the introduction of potent platelet inhibitors, such as the chimeric monoclonal antibody c7E3, to interventional cardiology, the utility of measuring and regulating procedural ACT has not been examined. To investigate the possible influence of platelet IIb/IIIa antagonism on procedural ACT, we reviewed data from the Evaluation of c7E3 Fab in the Prevention of Ischemic Complications (EPIC) trial. In the EPIC trial, 2,099 patients undergoing PTCA with a high risk of abrupt vessel closure were randomized to receive placebo (n = 696) or the IIb/IIIa platelet receptor antagonist c7E3 Fab (n = 1,403). Despite receiving less procedural heparin, and fewer patients receiving very high heparin doses (> 14,000 U) than the placebo group, those receiving c7E3 had a higher mean (401 vs 367 seconds, p < 0.001) ACT when corrected for body weight. The ACT is increased approximately 35 seconds by the platelet IIb/IIIa receptor antagonist c7E3 Fab. This has important implications for dosing conjunctive heparin therapy and performing PTCA or directional coronary atherectomy in the setting of IIb/IIIa-directed therapy.

Randomized trials of myocardial revascularization

Over the past two decades there has been considerable refinement in randomized cardiovascular clinical trials. The common aim of randomized clinical trials of myocardial revascularization has been to understand the relative benefits of each technique on survival and nonfatal end points. The bypass surgery versus medicine trials that began in the 1970s provided evidence that the patients with advanced ischemic heart disease--three-vessel disease and/or substantially impaired LV function--have the most to gain from aggressive therapy (i.e., bypass surgery). In these cases, surgical revascularization provides survival benefit and has emerged as the reference standard for providing the most definitive revascularization. In long-term follow-up, however, surgery does not reduce the occurrence of myocardial infarction or angina compared with medical therapy. For patients with less extensive atherosclerosis and/or preserved ventricular function, trials comparing medical therapy, percutaneous coronary interventions, and bypass surgery have shown similar medium-term rates of death and infarction. In general, patients undergoing bypass surgery require the fewest subsequent antianginal medications, whereas patients undergoing PTCA require a moderate amount of antianginal medications, and patients treated solely with medical therapy require the most antianginal medications. Regardless, during long-term follow-up a similarly high number of patients are angina-free, although patients in the PTCA group require reintervention more often. Among patients treated percutaneously, techniques such as balloon angioplasty, directional atherectomy, stenting, rotablation, and laser may be considered. Compared with balloon angioplasty, greater acute gains in angiographic lumen have been obtained after directional atherectomy and stenting, but at the expense of increased periprocedural infarction after atherectomy, increased peripheral vascular complications after stenting, and increased late loss of lumen after both. Elective stenting has been associated with improved clinical outcome, whereas laser and rotational atherectomy have not, in comparison to balloon angioplasty. Restenosis remains the major limitation of all percutaneous approaches. Guidance for the individual patient is often less straightforward. Although general conclusions can be derived from patients cohorts in randomized trials, only a "gestalt" can be provided for the individual patient. For example, we have poor predictive capacity for restenosis, especially when this is recurrent despite repeated intervention. Only the demographic criteria of severe unstable angina and insulin-dependent diabetes mellitus are helpful in categorizing patients as "restenosis-prone." A substantial number of patients do not fit into the criteria adopted for entry into the revascularization trials--a point that is all too frequently forgotten.(ABSTRACT TRUNCATED AT 400 WORDS)