Primary angioplasty for acute myocardial infarction in 1,000 consecutive patients. Results in an unselected population and high-risk subgroups

Current State of ST-Segment Myocardial Infarction: Evidence-based Therapies and Optimal Patient Outcomes in Advanced Systems of Care

Advances in reperfusion therapy for ST-segment elevation myocardial infarction (STEMI) provide optimal patient outcomes. Reperfusion therapies, including contemporary primary percutaneous coronary intervention, represent decades of clinical evidence development in large clinical trials and national databases. However, rapid identification of STEMI and guideline-directed management of patients across broad populations have been best achieved in advanced systems of care. Current outcomes in STEMI reflect the evolution of both clinical data and idealized health care delivery networks.

Current state of ST-segment myocardial infarction: evidence-based therapies and optimal patient outcomes in advanced systems of care

Advances in reperfusion therapy for ST-segment elevation myocardial infarction (STEMI) provide optimal patient outcomes. Reperfusion therapies, including contemporary primary percutaneous coronary intervention, represent decades of clinical evidence development in large clinical trials and national databases. However, rapid identification of STEMI and guideline-directed management of patients across broad populations have been best achieved in advanced systems of care. Current outcomes in STEMI reflect the evolution of both clinical data and idealized health care delivery networks.

Acute multivessel coronary artery occlusion: a case report

Background

In terms of clinical and angiographic findings, multiple simultaneous coronary occlusions in acute myocardial infarction are infrequent, and the mechanism of the occlusions is unclear.

Case presentation

We herein report a rare case of two simultaneously occluded coronary arteries, one of which subsequently underwent spontaneous lysis. An 88-year-old man had a 3-hour attack of acute crushing retrosternal chest pain. His first electrocardiogram showed ST-segment elevation in the inferior (II, III, and aVF) and anterior (V3–V6) leads. His second electrocardiogram in the cardiac care unit showed ST-segment elevation in the inferior leads but ST-segment depression in the anterior leads. Emergency coronary angiography revealed that the right coronary artery was acutely and totally occluded at the midportion and that the proximal and midportion of the left anterior descending coronary artery had an acute thrombus. According to his electrocardiogram and coronary angiography findings, we inferred that the right coronary artery and left anterior descending coronary artery first totally occluded simultaneously, and then the thrombus in the left anterior descending coronary artery spontaneously underwent partial lysis. Therefore, intervention of the right coronary artery was performed followed by injection of glycoprotein IIB-IIIA inhibitor into the left anterior descending coronary artery. He had an uneventful hospital course and was discharged home 10 days later.

Conclusion

Because patients with multivessel coronary artery occlusion are often in serious condition, abnormal electrocardiographic results must be identified and affected vessel should be opened timely and efficiently to save the myocardium and reduce complications such as congestive heart failure.

Assessing the appropriateness of coronary revascularization: the University of Maryland Revascularization Appropriateness Score (RAS) and its comparison to RAND expert panel ratings and American College of Cardiology/American Heart Association guidelines with regard to assigned appropriateness rating and ability to predict outcome

BACKGROUND

Significant regional variation in procedural frequencies has led to the development of the RAND and American College of Cardiology/American Heart Association (ACC/AHA) guidelines; however, they may be difficult to apply in clinical practice. The University of Maryland Revascularization Appropriateness Score (RAS) was created to address the need for a simplified point scoring system.

HYPOTHESIS

The study was undertaken to compare revascularization appropriateness ratings yielded by the RAND Expert Panel Ratings, ACC/AHA guidelines, and the University of Maryland RAS.

METHODS

We applied these three revascularization appropriateness scoring systems to 153 catheterization laboratory patients with a variety of cardiac diagnoses and treatments. For each patient, appropriateness scores assigned by each of the three systems were compared with each other and with the actual treatment delivered. Concordance of care with appropriateness score was then correlated with outcome.

RESULTS

There were significant differences among all three scoring systems in their ratings and in the concordance of treatment with appropriateness rating. When treatment provided was concordant with RAND ratings, there was a lower occurrence of subsequent coronary artery bypass grafting (CABG), the composite end point of either CABG or percutaneous transluminal coronary angioplasty (PTCA), and the composite end point of death, myocardial infarction (MI), or revascularization. When treatment was concordant with the ACC/AHA guidelines, there was lower occurrence of all-cause mortality, PTCA, the composite end point of either CABG or PTCA, and the composite end point of death, MI, or revascularization. When treatment provided was concordant with the RAS, there was lower occurrence of cardiac death, all-cause death, CABG, the composite end point of either CABG or PTCA, and the composite end point of death, MI, or revascularization.

CONCLUSIONS

The RAS is a simple scoring system to assess revascularization appropriateness. When the RAND, ACC/AHA, and RAS systems are compared in a catheterization laboratory population, they rate the same patient differently and vary in their correlation of appropriateness rating with outcome.

Early management of ST-segment elevation myocardial infarction

Improvements in the management of ST-segment elevation myocardial infarction(STEMI) have led to a reduction in the acute and long-term mortality rates. The first important decision in the care of patients who have STEMI is the method of reperfusion. Whether percutaneous intervention (PCI) or fibrinolytic therapy is chosen depends on a number of factors. This article reviews the data on PCI and fibrinolytics in the context of consensus guidelines, outlines adjunctive medical therapies important in the first 24 hours, and discusses a strategy for making the decisions and a hypothetical construct for evaluating new drugs and procedures in the future.

Impact of stents and abciximab on survival from cardiogenic shock treated with percutaneous coronary intervention

This retrospective observational review compares patient characteristics and in-hospital and long-term outcomes of cohorts of patients undergoing percutaneous coronary intervention (PCI) for cardiogenic shock complicating acute myocardial infarction (MI) prior to the use of stents (as well as glycoprotein IIb/IIIa inhibitor and dual-antiplatelet therapy) with PCI in the stent era. Cardiogenic shock remains the leading cause of hospital mortality from acute MI. This is a report of consecutive patients with cardiogenic shock complicating acute MI, without mechanical complication, referred for emergency catheterization to a single operator at two consecutive Veterans Affairs medical centers over a 15-year period (1988 to August 2003). PCI was attempted in all 93 cases: 44 consecutive patients in the present era and 49 consecutive patients in the stent era. Patients with comparable extent of coronary disease, more ST elevation myocardial infarction, multiple areas of infarction, and greater comorbidity underwent PCI in the stent era. Nevertheless, PCI in the stent era was associated with higher rates of acute success and improved in-hospital survival. Kaplan-Meier curves and log-rank testing showed highly significant improvement in overall survival (P < 0.0001). Logistic regression of in-hospital survival demonstrated that stent use (colinear with glycoprotein IIb/IIIa use and dual-antiplatelet therapy) was significantly associated with survival in a model adjusting for extent of coronary disease and comorbidities (P = 0.007). Stents and abciximab have been associated with improved acute angiographic and procedural success of PCI for cardiogenic shock, leading to improved survival.

Relation of mortality of primary angioplasty during acute myocardial infarction to door-to-Thrombolysis In Myocardial Infarction (TIMI) time

For primary angioplasty of acute myocardial infarction (AMI), the relation of treatment benefit and time has been debated. The present study aimed to evaluate, in a single-center cohort of patients with ST-segment elevation AMI, which time intervals were carefully and consistently measured, and the relations among ischemic time, in-hospital delays, and in-hospital survival. We included 499 patients (mean age 59 years; 80% men) who underwent successful primary percutaneous transluminal coronary angioplasty (PTCA) for AMI admitted < or =6 hours after symptom onset. The population was divided into tertiles with respect to time between onset of symptoms and admission, onset of symptoms to Thrombolysis In Myocardial Infarction (TIMI) grade 3 flow, and time from admission to TIMI grade 3 flow. Univariate analysis followed by multiple logistic regression was performed using the variables linked to mortality in the univariate analysis to assess the relation between predictor variables and in-hospital mortality. The in-hospital mortality rate was 3.2%. There was no significant relation between the various tertiles of time intervals and in-hospital mortality. After linear logistic regression, only age (odds ratio [OR] 1.79 per 10 years), female gender (OR 3.56), and door-to-TIMI 3 time (OR 1.27 per 15 minutes) were independently correlated with in-hospital mortality.

Reperfusion in acute myocardial infarction: current concepts

Myocardial reperfusion is the treatment of choice in acute myocardial infarction. Pharmacological thrombolysis restores coronary artery patency in about two thirds of patients with acute myocardial infarction. However, mechanical reperfusion with primary angioplasty and stenting achieves higher patency rates with less complications, especially in high-risk patients. Adjunctive pharmacotherapy and new device technology may improve the outcome of primary angioplasty. Facilitated angioplasty using a combination of half-dose thrombolysis, platelet glycoprotein IIb/IIIa antagonists, and early intervention, appears to be a promising strategy for the treatment of acute myocardial infarction in the modern era. The efficacy and safety of this approach are currently evaluated in several ongoing trials.

In-hospital and one-year outcomes for patients undergoing percutaneous coronary intervention for acute myocardial infarction

Previous studies have identified risk factors for short- and long-term outcomes for patients undergoing percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI). However, it remains unknown whether they can be generalized to current PCI practice for a broader cohort of patients. We analyzed the follow-up information (mortality and revascularization procedures) obtained from a nationwide Japanese registry during 1997 of a total of 2,211 patients with AMI who underwent PCI at 143 facilities. Demographic, clinical, angiographic, and procedural variables were submitted to statistical analysis to detect the risk factors of adverse outcomes. In-hospital and 1-year mortality rates were 7.1% and 10.9%, respectively. The most important risk factor for in-hospital death was attempted PCI of the left main (LM) coronary artery. Further independent risk factors for death were left ventricular (LV) dysfunction (ejection fraction </=40%), LM disease, older age, multivessel disease, cerebrovascular disease, and diabetes. The receiver-operating characteristics curve for the predicted probability of death was 0.88, indicating a good ability to discriminate high-risk patients. Independent risk factors for 1-year postdischarge mortality were LV dysfunction, older age, renal failure, multivessel disease, and diabetes. The incidence of the need for repeat PCI or bypass surgery was significantly higher in patients with multivessel and LM disease. PCI is a valuable treatment strategy for a broad spectrum of patients with AMI. However, the mortality for patients with LM disease and poor LV function is still high even using current practice standards.

Efficacy of heparin-coated stent in early setting of acute myocardial infarction

Primary stenting has been reported to be superior to balloon percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction (AMI) for recurrent ischemia, target lesion revascularization, and restenosis. However, concerns about early reocclusion or thrombosis after stenting in the very thrombotic environment of acute myocardial infarction still remain. Therefore, postprocedural short-term heparin or GpII(b)/III(a) receptor blockades has been used. The aim of our study was to evaluate the safety, feasibility, and long-term efficacy of heparin-coated stent in the early setting of AMI without postprocedural heparin or GpII(b)/III(a) receptor blockade infusion. We studied 102 consecutive patients presenting to cardiac catheterization laboratory < or = 6 hr from the onset of chest pain. No patients who were implanted with heparin-coated stents received heparin or GpII(b)/III(a) receptor blockade infusion after the procedures, not even patients who showed an angiographically large thrombus burden before stenting. Patients were evaluated for clinical endpoints at 30 days and 6 months. Coronary angiography was required for all patients at 2 weeks and 6 months after the procedure. Angiographic and procedural successes were 100% and 98%, respectively. Two patients (2%) died of heart failure without evidence of reocclusion of stented vessel during the hospitalization and 4 (4%) additional patients died of refractory heart failure within the first 6 months. Major bleeding complication occurred in one patient (1%). Recurrent myocardial infarction developed in one patient at 4 months. Early angiographic follow up at 2 weeks was performed in 88% of all patients, none of whom showed thrombotic stent occlusion. Six-month angiographic follow-up was completed in 71%(64/91) of eligible patients and binary restenosis was present in 17.2% of stented vessels. Eight(8%) patients underwent repeat PTCA. Cardiac event-free survival rate at 6 months was 86.3%. This study demonstrates that heparin-coated stents are safe in the early setting of acute myocardial infarction and no additional heparin infusion after stenting is necessary, which may reduce bleeding complications. Angiographic restenosis rate compares favorably to the binary restenosis rate from other studies with uncoated stents.

Outcome of acute ST-segment elevation myocardial infarction in patients with prior coronary artery bypass surgery receiving thrombolytic therapy

BACKGROUND

Patients with prior coronary bypass surgery with acute ST-segment elevation myocardial infarction (MI) pose an increasingly common clinical problem. We assessed the characteristics and outcomes of such patients undergoing thrombolysis for acute MI.

METHODS AND RESULTS

We compared the characteristics and outcomes of patients in the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries trial (GUSTO-I) who had had prior bypass (n = 1784, 4% of the population) with those without prior coronary artery bypass grafting (CABG), all of whom were randomized to receive one of four thrombolytic strategies. Patients with prior bypass were older with significantly more prior MI and angina. Overall, 30-day mortality was significantly higher in patients with prior bypass (10.7% vs 6.7% for no prior bypass, P <.001); these patients also had significantly more pulmonary edema, sustained hypotension, or cardiogenic shock. Patients with prior bypass showed a 12.5% relative reduction (95% confidence interval, 0% to 41.9%) in 30-day mortality with accelerated alteplase over the streptokinase monotherapies. In the 62% of patients with prior CABG who underwent coronary angiography, the infarct-related vessel was a native coronary artery in 61.9% and a bypass graft in 38.1% of cases. The Thrombolysis in Myocardial Infarction (TIMI) 3 flow rate was 30.5% for culprit native coronary arteries and 31.7% for culprit bypass grafts. Patients with prior bypass had more severe infarct-vessel stenoses (99% [90%, 100%] vs 90% [80%, 99%], P <.001).

CONCLUSIONS

The 30-day mortality in patients with prior CABG was significantly higher than that for patients without prior CABG. As in the overall trial, these patients derived an incremental survival benefit from treatment with accelerated alteplase, but mortality remained high (16.7%) at 1 year. These results are at least partially explained by the higher baseline risk of these patients and by the lower rate of patency of the infarct-related artery.

Myocardial ischemia-reperfusion damage impacts occurrence of ventricular fibrillation in dogs

To define the relationship between ischemia-reperfusion-induced myocardial damage (IRD) and the occurrence of ventricular tachycardia (VT) and fibrillation (VF), we studied 23 dogs with a three-dimensional activation mapping system. Left anterior descending (LAD) coronary artery occlusion and reperfusion were performed while recording electrograms during VF and atrial pacing. Prior nonischemic sites showing IRD, defined as at least 10% loss of electrogram voltage after reperfusion, had the longest ventricular effective refractory periods (ERPs). IRD sites also occurred more frequently in dogs with reperfusion VF (44 +/- 2 sites, P < 0.01) compared with dogs with VT (18 +/- 5 sites) and no VT (16 +/- 3 sites). In dogs (n = 3) with 3 h of reperfusion, 95% of IRD sites still had lower voltage than those recorded during occlusion. Activation mapping of the first eight complexes of VF had Purkinje or endocardial focal origin in 57%, and complexes originated from IRD sites in 28%. In contrast, dogs with only reperfusion VT also had Purkinje or endocardial focal origin in 79%, but only 5% (P < 0.01 vs. VF dogs) of the sites of origin had IRD. Therefore, dogs with reperfusion VF had more IRD sites where the ERP was longest, and more focal ventricular complexes originated from IRD sites, indicating that IRD may be one important factor in the occurrence of VF during reperfusion.

Interventional procedures in acute myocardial infarction

BACKGROUND

Acute myocardial infarction (MI) remains a leading cause of death in the United States. There is evidence that primary (direct) percutaneous intervention (PCI) may improve survival and reduce morbidity in patients with acute MI.

METHODS

We present a concise, comprehensive, evidence-based literature review of modern techniques of primary PCI in patients with acute MI. A comparison to thrombolytic therapy, especially in selected patient subgroups is made. Rescue angioplasty is also addressed. Adjunctive pharmacology, economic implications, and feasibility of implementation are discussed. A brief discussion of experimental therapies is included.

RESULTS

Primary PCI is an acceptable alternative to thrombolytic therapy in patients with acute MI and may result in superior outcomes in select patient populations, especially the elderly, patients with prior coronary artery bypass surgery, those with congestive heart failure, and those in cardiogenic shock.

CONCLUSIONS

Clinical trials support the use of primary PCI as first-line therapy for acute myocardial infarction. Patients in whom thrombolytic therapy is contraindicated or known to have reduced efficacy are also excellent candidates for this therapy. Ongoing advancements in equipment and adjunctive therapies continue to enhance delivery of this treatment as well as improve patient outcome.

Short- and long-term mortality for patients undergoing primary angioplasty for acute myocardial infarction

OBJECTIVES

The goal of this study was to learn more about the risk factors and short- and long-term outcomes for primary angioplasty.

BACKGROUND

Primary angioplasty (direct angioplasty without antecedent thrombolytic therapy) has been an effective alternative to thrombolytic therapy for patients with acute myocardial infarction (AMI). However, most reported studies have been compromised by small sample sizes and short observation times.

METHODS

New York's coronary angioplasty registry was used to identify New York patients undergoing angioplasty within 6 h of AMI between January 1, 1993 and December 31, 1996. Statistical models were used to identify significant risk factors for in-patient and long-term survival and to estimate long-term survival for all patients as well as various subsets of patients undergoing primary angioplasty.

RESULTS

The in-hospital mortality rate for all primary angioplasty patients was 5.81%. When patients in preprocedural shock (who had a mortality rate of 45%) were excluded, the in-hospital mortality rate dropped to 2.60%. Mortality rates for all primary angioplasty patients at one year, two years and three years were 9.3%, 11.3% and 12.6%, respectively. Patients treated with stent placement did not have significantly lower risk-adjusted in-patient or two-year mortality rates.

CONCLUSIONS

Primary angioplasty is a highly effective option for AMI.

Stent placement for non-STRESS/BENESTENT lesions: a critical review

Stenting lesions with favorable characteristics as required for inclusion in the STRESS/BENESTENT trials have yielded superior results to that of PTCA alone. Results for less favorable lesions such as in small vessels, diffuse disease, ostial disease, and saphenous vein grafts are less well established. This review seeks to analyze available data for stent placement in this subset of non-STRESS/BENESTENT lesions.

[Coronary angioplasty in the acute myocardial infarction: in which patients is it less likely to obtain an adequate coronary reperfusion?]

INTRODUCTION

In patients with acute myocardial infarction treated with primary angioplasty, the inability to achieve successful coronary reperfusion is associated with higher mortality. The objective of the study was to identify which characteristics may predict a lower angiographic success rate in patients with acute myocardial infarction treated with coronary angioplasty.

PATIENTS AND METHODS

The study population is constituted by the 790 patients with acute myocardial infarction that were treated with angioplasty within the 12 hours after the onset of symptoms from 1991 to 1999 at our institution. A successful angiographic result was considered in presence of a residual stenosis < 50% and a TIMI flow 2 or 3 after the procedure.

RESULTS

A successful angiographic result and a final TIMI 3 flow were achieved in 736 (93.2%) and 652 (82.5%) patients, respectively. In-hospital mortality was higher in patients with angiographic failure than in those with angiographic successful result (48 vs. 10%; p < 0.01). Age under 65 (91 vs. 95%; p = 0.02), non smoking (90 vs. 96%; p < 0,01), previous infarction (87 vs. 94%; p < 0.01), angioplasty after failed thrombolysis (83 vs. 94%; p = 0. 02), cardiogenic shock (80 vs. 95%; p < 0.01), undetermined location (67 vs. 93%; p < 0.01), non-inferior location (92 vs. 96%; p = 0.04), left bundle branch block (64 vs. 94%; p < 0.01), multivessel disease (91 vs. 95%; p = 0.02), left ventricular ejection fraction < 0.40 (89 vs. 97%; p < 0.01), no utilization of coronary stenting (90 vs. 96%; p < 0.01), and use of intraaortic balloon counterpulsation pump (82 vs. 95%; p < 0.01) were associated with a lower angiographic success rate. In the multivariable analysis, the following were independent predictors for angiographic failure: left bundle branch block (odds ratio [OR], 12.95; CI 95%, 3.00-53.90), cardiogenic shock (OR, 4.20; CI 95%, 1.95-8.75), no utilization of coronary stent (OR, 3.44; CI 95%, 1.71-7.37), and previous infarction (OR, 2.82; CI 95%, 1.29-5.90).

CONCLUSIONS

Coronary angioplasty allows a successful coronary recanalization in most patients with acute myocardial infarction. Some basic characteristics, however, may identify some subsets in which a successful angiographic result may be more difficult to obtain.

[One-year clinical and angiographic follow-up after primary stenting]

INTRODUCTION AND OBJECTIVES

The late reocclusion or restenosis rate of the infarct related artery is frequent after primary angioplasty. An implanted stent may be able to improve the coronary angioplasty results and long-term outcome of these patients. We present the clinical and angiographic outcome of a cohort of patients treated with primary stenting.

PATIENTS AND METHODS

A group of 74 consecutive patients with acute myocardial infarction treated with primary angioplasty and stenting were followed for one year. An angiographic control was performed at the 6th month of follow-up in 91% of patients to assess the restenosis and reocclusion rates of the infarct-related artery.

RESULTS

There were eight in-hospital deaths and three during follow-up (mortality rate 14.8%) and one non-fatal reinfarction (1.5%). The cumulative rate of recurrent ischemia was 6% at 3 months and 15% at 6 months, without any further increment at one-year follow-up. A new angioplasty was performed in 7 patients and three patients underwent surgical revascularization. Thus 80% of patients after discharge were free of events. The angiographic control showed only one reocclusion of the infarct related artery and a restenosis rate of 27%.

CONCLUSIONS

These results show that primary stenting is an effective procedure in treating non-selected patients with acute myocardial infarction with a low long-term incidence of adverse events and a low restenosis rate.

Synergy between intracoronary stenting and abciximab in improving angiographic and clinical outcomes of primary angioplasty in acute myocardial infarction

This study examined 650 consecutive patients who presented with an acute myocardial infarction and were treated with primary angioplasty within 12 hours of symptom onset between August 1995 and December 1998. Patients were placed into 4 treatment groups depending on the adjunctive therapy they received: group 1, percutaneous transluminal coronary angioplasty (PTCA) ("balloon PTCA alone"; n = 220); group 2, PTCA plus intracoronary stent placement ("stent"; n = 128); group 3, PTCA plus abciximab therapy ("abciximab"; n = 104); and group 4, PTCA plus intracoronary stent placement plus abciximab therapy ("stent/abciximab"; n = 198). The patients' clinical characteristics, severity of disease, and total ischemia time on presentation were similar. At baseline, abciximab and stent/abciximab groups had a higher incidence of thrombus on coronary angiography. Postprocedural quantitative coronary analysis showed a significantly larger minimum luminal diameter in the stent and stent/abciximab groups than PTCA alone. Overall, stents were most efficacious in reducing target vessel revascularization rate, whereas abciximab was associated with a higher postprocedural Thrombolysis In Myocardial Infarction-3 trial flow and less "no reflow." The best angiographic result was achieved in the stent/abciximab group. Similarly, the primary combined end point of death, myocardial infarction, and target vessel revascularization at 30 days was the lowest (6.1%) in the stent/abciximab group. The combination of abciximab and stenting in primary angioplasty for acute myocardial infarction is thus synergistic and is associated with improved angiographic and clinical results at 30-day follow-up.

Role of cardiac surgery in the hospital phase management of patients treated with primary angioplasty for acute myocardial infarction

Although cardiac surgery is performed in approximately 10% of acute myocardial infarction (AMI) patients undergoing a primary percutaneous transluminal coronary angioplasty (PTCA) reperfusion strategy before discharge, the indications for and timing of operative revascularization, and the short- and long-term outcomes after surgery have not been characterized. In the prospective, controlled Primary Angioplasty in Myocardial Infarction-2 trial, cardiac catheterization was performed in 1,100 patients within 12 hours of onset of AMI at 34 centers, followed by primary PTCA when appropriate. Cardiac surgery was performed before hospital discharge in 120 patients (10.9%), electively in 42.6%, and on an urgent or emergent basis in 57.4%. Surgery was performed in 6.1% of 982 patients after primary PTCA (although emergently for failed PTCA in only 4 cases [0.4%]), and in 53 of 118 patients (44.9%) not undergoing primary PTCA. Patients requiring surgery were older, and more frequently had diabetes and 3-vessel disease than those managed nonoperatively. Internal mammary artery grafts were placed in only 31% of patients. In-hospital mortality was 6.4% in patients undergoing urgent/emergent surgery, 2.0% after elective surgery, and 2.6% in patients not undergoing surgery (p = NS). After multivariate correction for baseline risk factors, early and late survival free of reinfarction were similar in patients undergoing versus not undergoing in-hospital cardiac surgery. Thus, the appropriate use of coronary artery bypass graft surgery in the peri-infarction period is an integral component of the primary PTCA approach, and is frequently used to optimize the prognosis of a high-risk AMI cohort with unfavorable baseline features. The implications for the performance of primary PTCA in AMI at centers without on-site surgical facilities are discussed.

Primary angioplasty for acute myocardial infarction in the elderly

Elderly patients with acute myocardial infarction present a formidable therapeutic challenge. Although there appears to be a survival benefit from thrombolytic therapy for the eligible elderly patient, persistent concerns regarding the risk of intracranial hemorrhage impedes utilization in this age group. Primary or direct angioplasty of the infarct artery has been proven to be an effective modality for reperfusion. Randomized comparisons suggest an advantage over thrombolysis in terms of achieving superior patency and mitigating recurrent ischemic events. Primary angioplasty expands the reperfusion population by including many patients ineligible for thrombolysis and is more effective for treating patients at high risk, such as those with cardiogenic shock. Acute angiography accumulates important prognostic and decision-facilitating information. The benefits of primary angioplasty are more impressive for the aging patient. The survival gain and reduction in intracranial hemorrhage may combine to magnify the advantages of performing angioplasty on patients in this group. Emerging evidence concerning the aging population validates continued examination of this invasive reperfusion approach.

Percutaneous transluminal coronary angioplasty performed 24-48 hours after the onset of acute myocardial infarction improves chronic-phase left ventricular regional wall motion

The authors investigated the capacity of percutaneous transluminal coronary angioplasty (PTCA) performed 24-48 hours after the onset of acute myocardial infarction (AMI) to improve regional left ventricular wall motion. Twenty-four patients were divided into two groups: a PTCA group who received successful PTCA (14 cases) and a non-PTCA group (10 cases) who did not receive PTCA. Left ventricular end-diastolic volume (LVEDV) increased significantly (p<0.01) from 57+/-14 mL/m2 during the acute phase to 83+/-16 mL/m2 during the chronic phase in the non-PTCA group, whereas no significant change in LVEDV was seen in the PTCA group (69+/-26 vs. 76+/-16 mL/m2). In addition, in patients with 99% stenosis/thrombolysis in myocardial infarction (TIMI) grade 3 flow, increases in regional left ventricular wall motion (delta(sd)/chord) at the infarcted site between the acute and chronic phases were significantly greater in the PTCA group than in the non-PTCA group (2.49+/-1.05 vs. 0.67+/-0.65, p<0.01). PTCA performed 24-48 hours after the onset of AMI improved wall motion at the infarcted site.

Clinical and angiographic outcomes in patients with previous coronary artery bypass graft surgery treated with primary balloon angioplasty for acute myocardial infarction. Second Primary Angioplasty in Myocardial Infarction Trial (PAMI-2) Investigators

OBJECTIVES

We sought to characterize the presenting characteristics of patients with previous coronary artery bypass graft surgery (CABG) and acute myocardial infarction (AMI) and to determine the angiographic success rate and clinical outcomes of a primary percutaneous transluminal coronary angioplasty (PTCA) strategy.

BACKGROUND

Patients who have had previous CABG and AMI comprise a high risk group with decreased reperfusion success and increased mortality after thrombolytic therapy. Little is known about the efficacy of primary PTCA in AMI.

METHODS

Early cardiac catheterization was performed in 1,100 patients within 12 h of onset of AMI at 34 centers in the prospective, controlled Second Primary Angioplasty in Myocardial Infarction trial (PAMI-2), followed by primary PTCA when appropriate. Data were collected by independent study monitors, end points were adjudicated and films were read at an independent core laboratory.

RESULTS

Of 1,100 patients with AMI, 58 (5.3%) had undergone previous CABG. The infarct-related vessel in these patients was a bypass graft in 32 patients (55%) and a native coronary artery in 26 patients. Compared with patients without previous CABG, patients with previous CABG were older and more frequently had a previous myocardial infarction and triple-vessel disease. Coronary angioplasty was less likely to be performed when the infarct-related vessel was a bypass graft rather than a native coronary artery (71.9% vs. 89.8%, p = 0.001); Thrombolysis in Myocardial Infarction trial (TIMI) flow grade 3 was less frequently achieved (70.2% vs. 94.3%, p < 0.0001); and in-hospital mortality was increased (9.4% vs. 2.6%, p = 0.02). As a result, mortality at six months was 14.3% versus 4.1% in patients with versus without previous CABG (p = 0.001). By multivariate analysis, independent determinants of late mortality in the entire study group were advanced age, triple-vessel disease, Killip class and post-PTCA TIMI flow grade <3.

CONCLUSIONS

Reperfusion success of a primary PTCA strategy in patients with previous CABG, although favorable with respect to historic control studies, is reduced as compared with that in patients without previous CABG. New approaches are required to treat patients with previous CABG and AMI, especially when the infarct-related vessel is a diseased saphenous vein graft.

Prevention of left ventricular remodeling by percutaneous transluminal coronary angioplasty performed 24 hours after the onset of acute myocardial infarction

It remains controversial whether percutaneous transluminal coronary angioplasty (PTCA) performed 24 hours after the onset of acute myocardial infarction (AMI) in coronary arteries with 99% stenosis is useful in preserving left ventricular function. We investigated the effectiveness of PTCA in preventing left ventricular remodeling when it was performed 24 hours after the onset of AMI in infarct-related coronary arteries (IRCAs) having 99% stenosis and thrombolysis in myocardial infarction (TIMI) grade 3 flow. The subjects were 19 patients with AMI (anterior wall, 9 patients; inferior wall, 7 patients; and non-Q, 3 patients) who, within 24 hours of the onset of AMI, underwent coronary angiography and left ventriculography during the acute and/ or chronic phases. The patients were divided into a PTCA group, comprised of patients in whom PTCA was successfully performed 24 hours after the onset of AMI (n = 10), and a non-PTCA group (n = 9). The non-PCTA group included patients who were successfully reperfused by thrombolysis and did not include patients who had spontaneous reperfusion or reperfusion after PTCA. In the non-PTCA group, the left ventricular end-diastolic volume (mean +/- SD) was significantly increased in the chronic phase (86 +/- 23 mL/m(2)) as compared with the acute phase (67 +/- 13 mL/m(2)), whereas in the PTCA group no significant difference was observed between end-diastolic volumes in the acute and chronic phases (67 +/- 26 and 68 +/- 13 mL/m(2), respectively). Left ventricular remodeling is prevented by PTCA when it is performed 24 hours after the onset of AMI in IRCAs with 99% stenosis and TIMI grade 3 flow.

Primary stent implantation is superior to balloon angioplasty in acute myocardial infarction: final results of the primary angioplasty versus stent implantation in acute myocardial infarction (PASTA) trial. PASTA Trial Investigators

Several studies have shown that stent implantations in acute myocardial infarction (AMI) result in better short- and long-term outcomes than primary balloon angioplasty. These results, however, have not been ascertained in randomized trials. We randomized 136 patients out of 208 patients with AMI within 12 hr from onset into two groups: 69 patients with primary balloon angioplasty (POBA group) and 67 patients with primary stent implantation (STENT group). We compared the incidences of major cardiac events (repeat MI, target lesion revascularization, and cardiac death) and angiographic parameters during hospitalization and follow-up periods up to 12 months in these two groups. There was no significant difference in the reperfusion success rates. The incidences of major cardiac events were lower in the STENT group than in the POBA group during hospitalization, the first 6 months and 12 months (6% vs. 19%, P = 0.023; 21% vs. 46%, P < 0.0001; 22% vs. 49%, P = 0.0011). Minimum lumen diameters were significantly bigger in the STENT group than the POBA group at predischarge angiogram and 6-month follow-up (2.85 +/- 0.62 vs. 2.08 +/- 0.82 mm, P < 0.0001; 2.24 +/- 0.64 vs. 1.72 +/- 0.76, P = 0.002). Restenosis rates at 6-month follow-up were significantly lower in the STENT group than in the POBA group (17% vs. 37.5%, P = 0.02). In selected patients with AMI, primary stent implantation results in a lower incidence of major cardiac events during the first 12 months, postprocedure, and less frequent 6-month restenosis than primary balloon angioplasty.

The role of coronary angioplasty and stenting in acute myocardial infarction

Despite the improvements in the pharmacological treatment of acute myocardial infarction, it is recognised that thrombolysis fails to reproduce reperfusion in a significant proportion of patients. Coronary interventional techniques have been shown to offer an alternative reperfusion strategy. There is increasing evidence that mechanical reperfusion may offer significant advantages over established thrombolytic therapy.

Results of coronary stenting after delayed angioplasty of the culprit vessel in patients with recent myocardial infarction

Little information is available concerning the effect of late coronary stenting in patients with recent myocardial infarction, especially long-term results. We retrospectively reviewed our results of 57 stent placements in 52 consecutive patients who received stents at an infarct-related lesion 24 hr to 30 days after an acute myocardial infarctions (median, 14 days). The average age was 67 years; 90% were male. Two patients who suffered from acute stent thrombosis received revascularization again and two early deaths were due to refractory cardiogenic shock before discharge. Mean patient clinical follow-up was 18.3 +/- 6.5 months. There were 1 subacute stent thrombosis, 1 cardiogenic death, and 10 patients (20.8%) in total suffering from angina class II to IV. Angiographic follow-up was performed in 36 patients (80%) at a mean of 7.5 +/- 3.1 months. Of these 36 patients, only 1 (3% of the total population undergoing follow-up angiography) had reocclusion at follow-up, but restenosis existed in 18 patients (50%). We conclude that there is still relatively high incidence of angiographic recurrence that is often silent in long-term follow-up, though the long-term result of late stenting in recent MI is low incidence of reocclusion.

Primary angioplasty for acute myocardial infarction resulting from the simultaneous occlusion of two major coronary arteries

Primary angioplasty for acute myocardial infarction is frequently performed. Not uncommonly, more than one occluded artery may be present. Usually only one is an acute event, the others being chronic occlusions. We encountered a patient who presented with two simultaneous occlusions; both were successfully recanalized. We discuss some observations that assisted us in devising our treatment strategy.

Primary percutaneous transluminal coronary angioplasty for acute myocardial infarction in patients not included in randomized studies. Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) Study Group

Patients with acute myocardial infarction included in randomized trials comparing primary percutaneous transluminal coronary angioplasty (pPTCA) with thrombolysis represent a special subgroup of patients with a low event rate. Patients excluded from these trials represent a variety of different subgroups, with different patient characteristics and possibly different clinical event rates. Primary PTCA was performed in 491 consecutive patients with acute myocardial infarction in the prospective multicenter observational Maximal Individual Therapy in Acute Myocardial Infarction trial. They were divided into the following groups: group I, patients fulfilling the inclusion criteria of the randomized trials (284 of 491, 58%); group II, patients not included in these trials (207 of 491, 42%). Of group II the following subgroups were defined: group IIa, patients in cardiogenic shock (20 of 491, 4.1%); group IIb, patients with a left bundle branch block (12 of 491, 2,4%); group IIc, patients with contraindications for thrombolysis (42 of 491, 8.6%); group IId, patients with a nondiagnostic first electrocardiogram (95 of 491, 19.3%); group IIe, patients with a prehospital delay of > 12 hours (72 of 491, 14.7%); group IIf, patients with an unknown prehospital delay (30 of 491, 6.1%). A comparison of groups I and II showed similar baseline characteristics but a higher clinical event rate during hospitalization was seen in group II: combined end point of death, reinfarction, heart failure equal to or greater than NYHA class III, any stroke or postinfarction angina, 26.6% versus 18%; p = 0.022. Hospital deaths were nearly twice as high in these patients, without reaching statistical significance (10.6% vs 6%; p = 0.06). The subgroups of group II showed quite different rates of clinical events. In-hospital death rates were: IIa, 40% (8 of 20); IIb, 8% (1 of 12); IIc, 12% (5 of 42); IId, 5% (5 of 95); IIe, 6% (4 of 72); and IIf, 13% (4 of 30). The incidence of the combined end point was 60% (12 of 20) in IIa, 33% (4 of 12) in IIb, 29% (12 of 42) in IIc, 16% (15 of 95) in IId, 26% (19 of 72) in IIe, and 33% (10 of 30) in IIf. Thus, in clinical practice, about half of the patients treated with pPTCA would not have been included in randomized trials comparing pPTCA with thrombolysis. These patients represent a population at higher risk for in hospital clinical events. However, they do represent very different nonhomogenous subgroups with different clinical event rates.

Update on mechanical revascularization in acute myocardial infarction: which role and when?

Mechanical revascularization in the acute myocardial infarction by primary angioplasty has several advantages over thrombolytic therapy. The short-term patency rates of the infarct-related artery range from 95 to 99% and a normal flow is achieved in more than 90% of the cases. This prompt and effective reperfusion is probably responsible for the improved prognosis with primary angioplasty. The better outcome after primary angioplasty is observed both in low- and in high-risk patients, in all ages and in patients presenting late (>6 h) after the chest pain. Pooled analysis of randomized studies, show that primary angioplasty as compared to thrombolysis, has a lower incidence of death, stroke and reinfarction. Additional advantages of primary PTCA include the possibility of reperfusion in patients in whom lysis is contraindicated or less effective (e.g. patients in cardiogenic shock, or with prior coronary artery bypass surgery) and the ability to provide prognostic information helpful in the patient triage. Thus, primary PTCA results in better outcome than thrombolysis when performed in centers with success rates comparable to those achieved in the randomized trials. Further studies are still needed to assess its long-term efficacy. Several randomized trials are underway to assess the role of stents and the use of more potent antiplatelet drugs, as the GPIIb/IIIa receptor blockers, in adjunct to balloon angioplasty in the treatment of acute myocardial infarction.

Differences in patients with acute myocardial infarction treated with primary angioplasty or thrombolytic therapy. Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) Study Group

BACKGROUND

Little is known about the differences in patients with acute myocardial infarction (AMI) treated with primary angioplasty or intravenous thrombolysis in clinical practice.

METHODS

In all, 5,906 patients with AMI were registered by the Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) study. Of these, 491 (8.3%) patients were treated with primary angioplasty and 2,817 (47.7%) with intravenous thrombolysis.

RESULTS

There were only minor differences in baseline characteristics between the two groups. Prehospital delay time (median) was longer in the angioplasty group than in the thrombolysis group (161 vs. 120, p = 0.001), as was door-to-treatment time (88 vs. 30 min; p = 0.001). Patients treated with primary angioplasty more often had contraindications for thrombolytic therapy (12.9 vs. 6%, p = 0.001) and received beta blockers (65 vs. 58.1%, p = 0.004), heparin (98.2 vs. 91.6%, p = 0.001), angiotensin-converting enzyme (ACE) inhibitors (64.8 vs. 50%, p = 0.001) and "optimal" concomitant medication (56.4 vs. 42.9%, p = 0.001) more often. Univariate analysis showed a significant lower incidence of heart failure (5.3 vs. 16.5%, p = 0.001), postinfarct angina (7.3 vs. 16.4%, p = 0.001), in-hospital death (7.9 vs. 11.7%, p = 0.015) and the combined end point (21.6 vs. 40.3%, p = 0.001) in these patients. Stepwise logistic regression analysis revealed optimal concomitant medication [odds ratio (OR) = 0.94, 95% confidence interval (CI): 0.89-0.98) and the type of revascularization (OR = 0.65, 95% CI: 0.58-0.73) to be associated with a significant reduction in the incidence of the combined end point. Similar results were obtained in all predefined subgroups.

CONCLUSIONS

In clinical practice, patients treated with primary angioplasty are more often treated with beta blockers and ACE inhibitors than patients treated with intravenous thrombolysis. Thus, the selection of patients and the type of revascularization contributes to the reduction in mortality, overt heart failure, and postinfarct angina in these patients.

Comparison of primary angioplasty with conservative therapy in patients with acute myocardial infarction and contraindications for thrombolytic therapy. Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) Study Group

The benefit of primary angioplasty in patients with acute myocardial infarction (AMI) and contraindications for thrombolysis compared to a conservative regimen is still unclear. Out of 5,869 patients with AMI registered by the MITRA trial, 337 (5.7%) patients had at least one strong contraindication for thrombolytic therapy. Out of these 337 patients 46 (13.6%) were treated with primary angioplasty and 276 (86.4%) were treated conservatively. Patients treated conservatively were older (70 years vs. 60 years; P=0.001), had a higher rate of a history with chronic heart failure (14.8% vs. 4.4%; P=0.053), a higher heart rate at admission (86 beats/min vs. 74 beats/min; P=0.001), and a higher prevalence of diabetes mellitus (27.1% vs. 12.8%; P=0.056). Patients treated with primary angioplasty received more often aspirin (91.3% vs. 74.6%; P=0.012), beta-blockers (60.9% vs. 46.1%; P = 0.062), angiotensin converting enzyme (ACE) inhibitors (71.7% vs. 44%; P=0.001), and the so-called optimal adjunctive medication (54.4% vs. 32.3%; P=0.004). Hospital mortality was significantly lower in patients who received primary angioplasty (univariate: 2.2% vs. 24.7%; P=0.001; multivariate: OR=0.46; P=0.0230). In patients with AMI and contraindications for thrombolytic therapy, primary angioplasty was associated with a significantly lower mortality compared to conservative treatment. Therefore, hospitals without the facilities to perform primary angioplasty should try to refer such patients to centers with the facilities for such a service, if this is possible in an acceptable time.

Incidence, consequences, and risk factors of early reocclusion after primary and/or rescue percutaneous transluminal coronary angioplasty for acute myocardial infarction

Percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction (AMI) achieves high patency rates. Conversely, it has been shown that after thrombolysis, early reocclusion of the infarct-related artery (IRA) is associated with substantial morbidity and mortality. The aim of this retrospective study was to study the incidence, prognostic implications, and clinical risk factors for in-hospital reocclusion of the IRA after successful emergency PTCA for AMI. We studied 399 consecutive patients (aged 59+/-14 years, 52% with anterior wall infarction) admitted <6 hours after AMI onset, of whom 374 (94%) were successfully treated with primary (n = 297) or rescue (n = 77) PTCA, with a stenting rate of 8%. Predischarge angiography was performed in 306 (82%). Early reocclusion of the IRA occurred in 28 patients (9%) and was silent in 6 (2%). The reocclusion rate was 10% for primary PTCA and 8% for rescue PTCA (p = NS). Twenty-two of 28 patients (6%) underwent repeat emergency coronary angiography because of early recurrent ischemia and most (n = 18) were treated with emergency PTCA. Early recurrent ischemia occurred mostly (86%) within 5 days of AMI onset. There was a higher prevalence of on-site hemorrhage (18% vs 5%, p = 0.007), blood transfusion (11% vs 2%, p = 0.01), pulmonary edema (21% vs 4%, p <0.01), and in-hospital death (21% vs 1%, p = 0.0001) in patients with predischarge reocclusion. On multivariate analysis, cardiogenic shock on admission and absence of dyslipidemia were strong and independent predictors (p = 0.01) of IRA reocclusion. In conclusion, early reocclusion after emergency PTCA occurred in 9% of the patients and was associated with substantial morbidity and mortality. This warrants attempts to decrease its incidence, e.g., with more frequent use of stents.

Primary coronary angioplasty in acute myocardial infarction: clinical correlates of the 'no reflow' phenomenon

The purpose of this study was to assess clinical correlates of the 'no reflow' phenomenon in 21 consecutive patients with acute myocardial infarction and complete occlusion of the infarct related artery (TIMI 0 flow) that underwent successful direct PTCA. After successful recanalization, 11 patients (group I) maintained TIMI 3 flow and ten patients presented with the 'no reflow' phenomenon (Group II). New Q wave on the surface ECG appeared in six patients in group I and in nine patients in group II (P=NS), clinical and radiologic signs of cardiac failure were detected in two patients in group I and in seven patients in group II (P<0.03). Early recurrence of ischemia was reported in three patients of group II but not in group I (P=NS). We conclude that the 'no reflow' phenomenon occurs in about half the cases of direct PTCA for complete occlusion and predicts adverse clinical events.

Dangers of delay of initiation of either thrombolysis or primary angioplasty in acute myocardial infarction with increasing use of primary angioplasty

We observed treatment delays and suboptimal outcomes when beginning to treat patients with acute myocardial infarction (AMI) with primary angioplasty. Of the 37 patients treated during a 12-month period, 12 (32%) required either emergency bypass surgery or died. Delayed time intervals to balloon reperfusion (mean 134 minutes) probably contributed to these adverse outcomes, with hemodynamic instability requiring pressors or intra-aortic balloon pumping in 15 patients, 12 (75%) before the first balloon inflation. Eleven of the 12 patients with significant adverse outcomes required such intervention. As angioplasty use increased, time intervals to thrombolysis in those not treated with angioplasty increased from an average of 29 minutes (53% treated less than the national standard of 30 minutes) to 39 minutes (32% treated <30 minutes, p <0.001). During the last 2 months of the study period, the time intervals had increased to 48 minutes (14% treated <30 minutes, p <0.0001). There was no change in thrombolytic time intervals at a local community hospital that did not offer primary angioplasty. Emergency Department physician confusion about the best therapy (angioplasty or thrombolysis) was documented in the medical records in 42% of cases (53 of 127). Confusion regarding therapy of AMI led to unacceptable delays in the administration of thrombolytic agents and probably contributed to the adverse outcomes in patients receiving primary angioplasty.

Comparison of primary coronary stenting to primary balloon angioplasty with stent bailout for the treatment of patients with acute myocardial infarction

This study compares the immediate and long-term outcomes of a primary coronary stenting strategy with primary balloon angioplasty with stent bailout in the treatment of patients with acute myocardial infarction (AMI). One hundred forty-seven consecutive patients who underwent primary balloon angioplasty with stent bailout (n = 94) or primary stenting (n = 53) for AMI were clinically followed for 8.1 +/- 5.7 and 8.5 +/- 4.5 months, respectively. Immediate results, as well as in-hospital and long-term ischemic events (death, reinfarction, and repeat revascularization) were compared between both groups. Angiographic success was 91.5% in the balloon angioplasty group and 94% in the stent group. In-hospital and late follow-up combined ischemic events were 22 of 94 (23%) versus 0 of 53 (0%); p < 0.001 and 33 of 78 (42%) versus 13 of 53 (25%), p = 0.04 for the balloon angioplasty and stent groups, respectively. At 6 months, the cumulative probability of repeat target lesion revascularization was higher in the balloon angioplasty group (47% vs 18%, p = 0.0006) as was the probability of late target revascularization (36% vs 18%, p = 0.046); the cumulative event-free survival after 6 months was significantly lower in the balloon angioplasty group (44% vs 80%, p = 0.0001). This study demonstrates that a primary stent placement strategy in patients with AMI is safe, feasible, and superior to primary balloon angioplasty with stent bailout. Primary stenting results in a larger postprocedural minimal luminal diameter, a lower early and late recurrent ischemic event rate, and a lower incidence of target lesion revascularization at follow-up.

Percutaneous transluminal coronary angioplasty (PTCA) without on-site surgical facilities

BACKGROUND

Numerous publications from European and Canadian centres have documented the feasibility of performing percutaneous transluminal coronary angioplasty (PTCA) without on-site surgical facilities. The absolute need for surgical standby has been changing especially with the introduction of coronary stent for bailout situations. This practice may be applicable in Australian centres especially in the environment of long waiting lists and cost containment.

AIM

To review the safety of performing PTCA by experienced operators in two Melbourne hospitals without on-site surgical facilities.

METHODS

We reviewed data of all patients who had PTCA electively (with low and moderate risks) between July 1996 and January 1997 and in the setting of acute myocardial infarction (AMI) from January 1996 to January 1997. Surgical standby was available as 'next available room' basis in nearby centres. Immediate outcome before discharge was documented and follow up from three to six months in 80% of all surviving patients.

RESULTS

There were 46 elective PTCA and 41 PTCA for AMI. PTCA was successful in 82 (94%) patients. Among the elective cases, seven patients were already inpatients with unstable or postinfarct angina. Thirteen patients had stents deployed with three for acute closure. Abciximab (Reopro) was given to eight patients. Two patients had acute closure in the laboratory which could not be reopened, but did not require emergency coronary artery bypass grafting (CABG). There were four inhospital deaths (three related to AMI and one died of a noncoronary cause).

CONCLUSION

PTCA can be performed electively in a selected group of patients with coronary artery disease and as a primary procedure for AMI without on-site surgical standby.