Importance of time to reperfusion for 30-day and late survival and recovery of left ventricular function after primary angioplasty for acute myocardial infarction

Predictors and prognosis of suboptimal coronary blood flow after primary coronary angioplasty in patients with acute myocardial infarction

We hypothesized that certain clinical and angiographic characteristics on presentation predict suboptimal infarct artery flow after percutaneous intervention during acute myocardial infarction (AMI). The goal of angioplasty (percutaneous transluminal coronary angioplasty [PTCA]) during AMI is the prompt restoration of normal flow to achieve myocardial reperfusion. However, inadequate epicardial coronary flow is observed in 10% to 20% of patients. From 2 large randomized trials-Global Use of Strategies To open Occluded arteries in Acute Coronary Syndromes-IIb, and Randomized Placebo-Controlled Trial of Platelet glycoprotein IIb/IIIa Blockade With Primary Angioplasty for Acute Myocardial Infarction-patients undergoing primary PTCA during AMI were included in the analysis. A multivariate logistic model was used to identify factors associated with final Thrombolysis In Myocardial Infarction (TIMI) flow grade < or =2. The 891 patients were aged (mean +/- SD) 61 +/- 12 years, 75% were men, and 39% had an anterior wall AMI. Patients underwent PTCA within 4.8 +/- 3.2 hours from the onset of chest pain. The incidence of final TIMI 3 flow was 81%. TIMI flow grade < or =2 was independently associated with increasing age (odds ratio [OR] 1.39 for every 10 years, 95% confidence interval [CI] 1.19 to 1.62), increasing heart rate (OR 1.16 for every 10 beats, 95% CI 1.05 to 1.28), and presence of visible thrombus on baseline angiogram (OR 1.89, 95% CI 1.18 to 3.05). Conversely, baseline TIMI 2 or 3 flow grade (OR 0.46, 95% CI 0.28 to 0.75) and left circumflex intervention (OR 0.42, 95% CI 0.23 to 0.79) correlated with normal postprocedural coronary flow. Mortality was significantly higher in patients with TIMI < or =2 than TIMI 3 flow grade (10.2% vs 1.5%, p <0.001, respectively). Thus, angiographic evidence of thrombus and 2 pivotal clinical characteristics, advanced age and elevated heart rate, predict lack of adequate coronary reperfusion. Conversely, the presence of normal or near-normal coronary flow before intervention correlates with a good angiographic result. Mortality risk is increased in patients with postprocedural suboptimal angiographic coronary flow.

Impact of prehospital delay on mortality in patients with acute myocardial infarction treated with primary angioplasty and intravenous thrombolysis

BACKGROUND

In patients with acute myocardial infarction treated with thrombolysis, longer times to treatment are associated with increasingly worse clinical outcome. This relation may be different for treatment with primary angioplasty.

METHODS

We analyzed the pooled data of the German acute myocardial infarction registries Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) and Myocardial Infarction Registry (MIR) to determine the influence of prehospital delays on hospital mortality rates. Primary angioplasty was performed in 1063 patients and thrombolysis in 7552 patients.

RESULTS

In patients treated with thrombolysis, in-hospital time to treatment was constantly 30 minutes median. In patients treated with primary angioplasty, in-hospital time to treatment increased from 60 minutes median up to 87 minutes median with increasing prehospital delay. Hospital mortality rates slightly decreased with increasing prehospital delays in patients treated with primary angioplasty (P for trend =.02). However, in patients treated with thrombolysis, mortality rate was nonsignificantly increased (P for trend =.11). Logistic regression analysis showed no significant difference in mortality rates between primary angioplasty and thrombolysis for prehospital delays of <3 hours. However, when prehospital delay was >3 hours, thrombolysis was independently associated with a higher mortality rate compared with primary angioplasty.

CONCLUSIONS

Compared with thrombolysis, primary angioplasty is independently associated with a lower mortality rate in prehospital delays of >3 hours. The reason for this may be a time-dependent loss of efficacy to achieve reperfusion for thrombolysis but not for primary angioplasty.

Influence of treatment delay on long-term left ventricular function in patients with acute myocardial infarction successfully treated with primary angioplasty

BACKGROUND

Myocardial salvage has been shown to be dependent on the time elapsed from the onset of acute myocardial infarction (AMI) to reperfusion. The aim of this study was to evaluate the importance of time to reperfusion for left ventricular function recovery after primary angioplasty (percutaneous transluminal coronary angioplasty [PTCA]) for AMI.

METHODS

Ninety-five patients undergoing long-term successful PTCA for AMI were studied. Echocardiography was performed before and 3, 7, 30, 90, and 180 days after PTCA. End-diastolic volume index (EDVI) and end-systolic volume index (ESVI), ejection fraction, and left ventricular wall motion score index (WMSI) were evaluated.

RESULTS

Patients were divided into group A, 23 patients reperfused within 2 hours; group B, 32 patients reperfused between 2 and 4 hours; group C, 22 patients reperfused between 4 and 6 hours; and group D, 18 patients reperfused between 6 and 12 hours. Both EDVI and ESVI were reduced in groups A and B at 90 days. Groups C and D did not show any changes of EDVI and ESVI at any stage throughout the study. Ejection fraction improved only in groups A and B at 30, 90, and 180 days. At study entry, WMSI was similar in all groups. After 7 days, in group A and in group B, WMSI was improved, no changes were observed in group C, and a mild deterioration was observed in group D at 3 and 7 days. Subsequent evaluations showed progressive improvement of WMSI in all groups.

CONCLUSIONS

Myocardial salvage is achieved only in patients revascularized within 4 hours from AMI onset. However, revascularization after 6 hours may be worthwhile by preventing ventricular remodeling.

Effect of audit on door-to-inflation times in primary angioplasty/stenting for acute myocardial infarction

We found that after audit and physician-guided changes in our protocol, the door-to-inflation times for primary angioplasty/stenting were markedly reduced. Because our preaudit mean time was similar to the national average, this may have wide applicability.

Management of acute coronary syndromes in the community hospital without cardiac surgical capability: how can access to interventional therapy be improved?

Early coronary artery intervention is emerging as the treatment of choice for patients with high risk acute coronary syndromes (ACS). However, most patients with ACS are admitted to hospitals which do not have ready access to interventional therapy. Extending the benefits of early intervention to this population is problematic at such community hospitals, since this approach would require either emergency transfer to a tertiary center or the performance of angioplasty on-site at hospitals without cardiac surgical capability. A third solution, pre-hospital ambulance triage to interventional centers, is not currently practised in most countries. A growing body of evidence indicates that hospitals without cardiac surgical capability can establish safe and effective primary angioplasty programs. Patients with acute myocardial infarction (AMI) who are randomized to transfer for primary angioplasty without fibrinolytic treatment have fewer major adverse cardiac events than those treated with fibrinolytics alone or fibrinolytics and transfer. In patients with unstable angina (UA) or non-ST-elevation AMI, an early aggressive approach led to a significant reduction in the composite end-point of death, AMI, or rehospitalization for recurrent UA at 6 months with no increase in cost, compared with conservative management. Ongoing trials in Europe indicate that pre-hospital ambulance triage of patients with large AMI to interventional centers can be remarkably rapid, safe, and effective. In order to improve the access of such patients to early intervention, 3 interdependent solutions are proposed:The development of more interventional programs at those hospitals without cardiac surgical facilities that can meet rigorous standards. The development of protocols to insure the early and more frequent transfer of patients with high-risk ACS to interventional centers for coronary angiography and revascularization. The pre-hospital triage of patients with AMI to established heart attack centers with 24-hour, 365-day emergency interventional capability for immediate primary angioplasty (after the model of trauma centers). Universal triage/transfer of all such patients to interventional centers could, however, quickly flood the capability of all tertiary surgical hospitals. With the aging of the 'baby boomers' in the near future, the need for interventional facilities will increase even further. Thus the second and third solutions above will ultimately depend on the first solution. Improving the delivery of interventional therapy to patients with ACS can provide a substantial healthcare benefit to society.

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.

Debate: Should the elderly receive thrombolytic therapy or primary angioplasty?

Thrombolysis and primary angioplasty are both recommended reperfusion strategies for elderly patients presenting with myocardial infarction (MI). Primary angioplasty is most beneficial in high-risk patients. While the elderly have a high absolute risk of dying or developing complications after MI, they also have an increased risk of intracranial haemorrhage if they are given thrombolytic therapy. It could therefore be reasonably argued that primary angioplasty is the reperfusion strategy of choice in the elderly. However, primary angioplasty has not been shown to have a greater relative benefit than thrombolytic therapy in the elderly. Recent data from the Fibrinolytic Therapy Trialists' (FTT) Collaborative Group show that thrombolytic therapy significantly reduces mortality compared with control treatment in patients over 75 years of age presenting within 12 h of symptom onset, with ST-segment elevation or bundle branch block. Future advances in adjunctive therapies may improve myocyte perfusion and hence the outcomes achieved by both invasive and noninvasive reperfusion strategies. Better thrombolytic regimens incorporating adjunctive agents such as bivalirudin may reduce the risk of intracranial haemorrhage. Few hospitals can provide a 24-h primary angioplasty service with door-to-balloon times consistently less than 90 min, and thrombolytic therapy is therefore a far more practical option in most instances.

Do new devices add to the results of PTCA in acute myocardial infarction?

Several randomized trials have established that timely mechanical reperfusion with the use of balloon angioplasty is superior to thrombolytic therapy in patients with acute myocardial infarction. Furthermore, recent data from prospective randomized trials suggest that primary stent implantation may further improve the results of balloon angioplasty by reducing the need for repeat interventions at follow-up. The role of IIb-IIIa platelet receptor antagonists as adjunctive therapy to catheter-based coronary interventions in acute myocardial infarction is promising, but the incremental benefit that these agents add to stent implantation awaits the results of dedicated randomized trials. Mechanical thrombolysis or thrombectomy devices may have a role in a minority of patients with large thrombus burden.

Interventional Cardiology: Advances in Percutaneous Techniques for the Treatment of Cardiac Disease

The field of interventional cardiology began in the late 1970s and consisted primarily of balloon catheter angio plasty until the early 1990s. Although understanding of the process of coronary angioplasty has evolved signifi cantly, restenosis still remains the Achilles' heel of the interventional cardiologist. This article reviews the cur rent issues involved in interventional cardiology for coronary disease from patient selection, anticoagulant therapy, restenosis, current interventional devices (stent mania), and future devices (intracoronary radiation). Noncoronary interventional procedures, vaivuloplasty, and atrial septal defect closure are also reviewed to provide an overview of cardiac interventional proce dures for the anesthesiologist.

Treatment of acute myocardial infarction by primary coronary angioplasty or intravenous thrombolysis in the "real world": one-year results from a nationwide French survey

BACKGROUND

Recent randomized trials comparing primary coronary angioplasty and intravenous thrombolysis at the acute stage of myocardial infarction have shown a limited but definite advantage for primary angioplasty. The aim of this study was to document 1-year outcome in patients receiving either thrombolysis or primary angioplasty for acute myocardial infarction in the "real world."

METHODS AND RESULTS

We used a nationwide prospective registry of all patients admitted for acute myocardial infarction in French intensive care units in November 1995. Of the 721 patients who received reperfusion therapy, 152 were treated with primary angioplasty and 569 received intravenous thrombolysis. The two groups were remarkably similar with respect to all baseline descriptors, except that a higher proportion of patients in the angioplasty group had a history of cerebrovascular accident (10% versus 2%, P<0.01). In-hospital outcome was not different in the 2 groups. One-year survival was 85.5% in the angioplasty group and 89. 5% in the thrombolysis group (P=0.18). Multivariate analysis showed that older age, anterior location of infarction, female sex, and history of heart failure were related to 1-year mortality. In patients alive on day 5, the use of primary angioplasty and higher Killip class were additional adverse prognostic indicators.

CONCLUSIONS

The results of this large registry of real-world practice indicate no survival benefit for patients treated with primary angioplasty compared with those who received thrombolytic therapy.