Amadeo Betriu

Management of acute myocardial infarction in patients presenting with ST-segment elevation

Summary: initial diagnosis of acute myocar-dial infarction •History of chest pain/discomfort.•ST-segment elevations or (presumed) new leftbundle-branch block on admission ECG. RepeatedECG recordings often needed.•Elevated markers of myocardial necrosis (CK-MB,troponins). One should not wait for the results toinitiate reperfusion treatment!•2D echocardiography and perfusion scintigraphyhelpful to rule out acute myocardial infarction. Relief of pain, breathlessness and anxiety Relief of pain is of paramount importance, not onlyfor humane reasons but because the pain is associ-ated with sympathetic activation which causesvasoconstriction and increases the workload of theheart. Intravenous opioids—morphine or, whereavailable, diamorphine—are the analgesics mostcommonly used in this context (e.g. 4 to 8 mgmorphine with additional doses of 2 mg at intervalsof 5 min until the pain is relieved); intramuscularinjections should be avoided. Repeated dosesmay be necessary. Side effects include nausea andvomiting, hypotension with bradycardia, andrespiratory depression. Antiemetics may be admin-istered concurrently with opioids. The hypotensionand bradycardia will usually respond to atropine,and respiratory depression to naloxone, whichshould always be available. If opioids fail to relievethe pain after repeated administration, intra-venous beta-blockers or nitrates are sometimeseffective. Oxygen (2– 4l.min

Predictors of 30-Day Mortality in the Era of Reperfusion for Acute Myocardial Infarction Results From an International Trial of 41 021 Patients

BACKGROUND Despite remarkable advances in the treatment of acute myocardial infarction, substantial early patient mortality remains. Appropriate choices among alternative therapies and the use of clinical resources depend on an estimate of the patients risk. Individual patients reflect a combination of clinical features that influence prognosis, and these factors must be appropriately weighted to produce an accurate assessment of risk. Prior studies to define prognosis either were performed before widespread use of thrombolysis or were limited in sample size or spectrum of data. Using the large population of the GUSTO-I trial, we performed a comprehensive analysis of relations between baseline clinical data and 30-day mortality and developed a multivariable statistical model for risk assessment in candidates for thrombolytic therapy. METHODS AND RESULTS For the 41,021 patients enrolled in GUSTO-I, a randomized trial of four thrombolytic strategies, relations between clinical descriptors routinely collected at initial presentation, and death within 30 days (which occurred in 7% of the population) were examined with both univariable and multivariable analyses. Variables studied included demographics, history and risk factors, presenting characteristics, and treatment assignment. Risk modeling was performed with logistic multiple regression and validated with bootstrapping techniques. Multivariable analysis identified age as the most significant factor influencing 30-day mortality, with rates of 1.1% in the youngest decile (< 45 years) and 20.5% in patients > 75 (adjusted chi 2 = 717, P < .0001). Other factors most significantly associated with increased mortality were lower systolic blood pressure (chi 2 = 550, P < .0001), higher Killip class (chi 2 = 350, P < .0001), elevated heart rate (chi 2 = 275, P < .0001), and anterior infarction (chi 2 = 143, P < .0001). Together, these five characteristics contained 90% of the prognostic information in the baseline clinical data. Other significant though less important factors included previous myocardial infarction, height, time to treatment, diabetes, weight, smoking status, type of thrombolytic, previous bypass surgery, hypertension, and prior cerebrovascular disease. Combining prognostic variables through logistic regression, we produced a validated model that stratified patient risk and accurately estimated the likelihood of death. CONCLUSIONS The clinical determinants of mortality in patients treated with thrombolytic therapy within 6 hours of symptom onset are multifactorial and the relations complex. Although a few variables contain most of the prognostic information, many others contribute additional independent prognostic information. Through consideration of multiple characteristics, including age, medical history, physiological significance of the infarction, and medical treatment, the prognosis of an individual patient can be accurately estimated.

Facilitated PCI in Patients with ST-Elevation Myocardial Infarction

BACKGROUND We hypothesized that percutaneous coronary intervention (PCI) preceded by early treatment with abciximab plus half-dose reteplase (combination-facilitated PCI) or with abciximab alone (abciximab-facilitated PCI) would improve outcomes in patients with acute ST-segment elevation myocardial infarction, as compared with abciximab administered immediately before the procedure (primary PCI). METHODS In this international, double-blind, placebo-controlled study, we randomly assigned patients with ST-segment elevation myocardial infarction who presented 6 hours or less after the onset of symptoms to receive combination-facilitated PCI, abciximab-facilitated PCI, or primary PCI. All patients received unfractionated heparin or enoxaparin before PCI and a 12-hour infusion of abciximab after PCI. The primary end point was the composite of death from all causes, ventricular fibrillation occurring more than 48 hours after randomization, cardiogenic shock, and congestive heart failure during the first 90 days after randomization. RESULTS A total of 2452 patients were randomly assigned to a treatment group. Significantly more patients had early ST-segment resolution with combination-facilitated PCI (43.9%) than with abciximab-facilitated PCI (33.1%) or primary PCI (31.0%; P=0.01 and P=0.003, respectively). The primary end point occurred in 9.8%, 10.5%, and 10.7% of the patients in the combination-facilitated PCI group, abciximab-facilitated PCI group, and primary-PCI group, respectively (P=0.55); 90-day mortality rates were 5.2%, 5.5%, and 4.5%, respectively (P=0.49). CONCLUSIONS Neither facilitation of PCI with reteplase plus abciximab nor facilitation with abciximab alone significantly improved the clinical outcomes, as compared with abciximab given at the time of PCI, in patients with ST-segment elevation myocardial infarction. (ClinicalTrials.gov number, NCT00046228 [ClinicalTrials.gov].)

Relationship Between Delay in Performing Direct Coronary Angioplasty and Early Clinical Outcome in Patients With Acute Myocardial Infarction Results From the Global Use of Strategies to Open Occluded Arteries in Acute Coronary Syndromes (GUSTO-IIb) Trial

BACKGROUND Time to treatment with thrombolytic therapy is a critical determinant of mortality in acute myocardial infarction. Little is known about the relationship between the time to treatment with direct coronary angioplasty and clinical outcome. The objectives of this study were to determine both the time required to perform direct coronary angioplasty in the Global Use of Strategies to Open Occluded Arteries in Acute Coronary Syndromes (GUSTO-IIb) trial and its relationship to clinical outcome. METHODS AND RESULTS Patients randomized to direct coronary angioplasty (n=565) were divided into groups based on the time between study enrollment and first balloon inflation. Patients randomized to angioplasty who did not undergo the procedure were also analyzed. The median time from study enrollment to first balloon inflation was 76 minutes; 19% of patients assigned to angioplasty did not undergo an angioplasty procedure. The 30-day mortality rate of patients who underwent balloon inflation </=60 minutes after study enrollment was 1.0%; 61 to 75 minutes after enrollment, 3.7%; 76 to 90 minutes after enrollment, 4.0%; and >/=91 minutes after enrollment, 6.4%. The mortality rate of patients assigned to angioplasty who never underwent the procedure was 14.1% (P=0.001). Logistic regression analysis revealed that the time from enrollment to first balloon inflation was a significant predictor of mortality within 30 days; after adjustment for differences in baseline characteristics, the odds of death increased 1.6 times (P=0.008) for a movement from each time interval to the next. CONCLUSIONS The time to treatment with direct PTCA, as with thrombolytic therapy, is a critical determinant of mortality.

Determinants of prognosis in survivors of myocardial infarction: a prospective clinical angiographic study.

To identify predictors of late mortality, 259 consecutive men (less than or equal to 60 years old) who survived acute myocardial infarctions were catheterized one month after admission and were then followed for a mean of 34 months. Nineteen patients (7 per cent) died during the observation period. Of 79 base-line descriptors, 17 proved to be univariate predictors of survival. Cox regression analysis demonstrated that the ejection fraction (P less than 0.001), the number of diseased vessels (P less than 0.005), and the occurrence of congestive heart failure in the coronary unit (P less than 0.01) were the only independent predictors of survival. Risk stratification showed that the probability of survival at four years was highest in patients with normal ejection fractions (96 to 100 per cent, depending on the number of diseased vessels) and lowest in those with ejection fractions below 20 per cent (3o to 75 per cent). The prognosis in patients with ejection fractions between 21 and 49 per cent was significantly worse (78 per cent) than in those with normal ejection fractions only in the group with three-vessel involvement (P less than 0.01). Since most survivors of myocardial infarction who are likely to have their lives prolonged by coronary-artery bypass surgery are in this group, it is reasonable to limit routine coronary angiography to the 56 per cent of survivors who have ejection fractions between 21 and 49 per cent.

Link Between the Angiographic Substudy and Mortality Outcomes in a Large Randomized Trial of Myocardial Reperfusion Importance of Early and Complete Infarct Artery Reperfusion

BACKGROUND The Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries (GUSTO-I) trial was designed to test whether thrombolytic strategies achieving more complete, early, sustained coronary artery patency would lead to further reductions in mortality in patients with acute myocardial infarction. An angiographic substudy within GUSTO-I provided a unique opportunity to examine the relation between mortality and degrees of patency among the regimens. METHODS AND RESULTS Four thrombolytic strategies were compared in 41,021 patients in GUSTO-I: streptokinase with subcutaneous or intravenous heparin, accelerated tissue plasminogen activator (TPA) with intravenous heparin, and combination streptokinase plus TPA with intravenous heparin. Accelerated TPA was associated with lower 30-day mortality (6.3%) than the other strategies (7.2%, 7.4%, and 7.0%, respectively). Among the 1210 patients in the angiographic substudy randomized to angiography 90 minutes after starting treatment, there was improved patency, particularly Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow, with accelerated TPA over the other regimens (P < .0001). Coronary artery perfusion (TIMI grade 3) at 90 minutes was also a significant predictor of 30-day survival (P < .01). To determine whether differences in mortality among the four strategies matched differences in 90-minute patency, a model was developed for predicting mortality differences in the main trial from the angiographic substudy. The model assumed that any differences in treatment effects on 30-day mortality were mediated through differences in 90-minute patency for the four treatments. The predicted rates were then compared with observed mortality rates of the remaining patients in the main trial for each treatment group. The predicted and observed 30-day mortality rates of the four treatments were streptokinase with subcutaneous heparin, 7.46% versus 7.28%; streptokinase with intravenous heparin, 7.26% versus 7.39%; accelerated TPA, 6.31% versus 6.37%; and streptokinase plus TPA, 6.98% versus 6.96%. The correlation between predicted and observed results was .97, and the proportion of squared error explained (R2) was .92. CONCLUSIONS The close relation between the predicted and observed 30-day mortality rates supports the concept that an important mechanism for improved survival with thrombolytic therapy is achievement of early, complete perfusion. The close match provides a strong biological explanation for the mortality differences seen in GUSTO-I and a sound rationale for the additional survival advantage of the accelerated TPA regimen. Irrespective of which treatment is used, early and complete restoration of infarct artery perfusion represents an essential goal of myocardial reperfusion therapy.

Reperfusion therapy for ST elevation acute myocardial infarction in Europe: description of the current situation in 30 countries

Aims Patient access to reperfusion therapy and the use of primary percutaneous coronary intervention (p-PCI) or thrombolysis (TL) varies considerably between European countries. The aim of this study was to obtain a realistic contemporary picture of how patients with ST elevation myocardial infarction (STEMI) are treated in different European countries. Methods and results The chairpersons of the national working groups/societies of interventional cardiology in European countries and selected experts known to be involved in the national registries joined the writing group upon invitation. Data were collected about the country and any existing national STEMI or PCI registries, about STEMI epidemiology, and treatment in each given country and about PCI and p-PCI centres and procedures in each country. Results from the national and/or regional registries in 30 countries were included in this analysis. The annual incidence of hospital admission for any acute myocardial infarction (AMI) varied between 90–312/100 thousand/year, the incidence of STEMI alone ranging from 44 to 142. Primary PCI was the dominant reperfusion strategy in 16 countries and TL in 8 countries. The use of a p-PCI strategy varied between 5 and 92% (of all STEMI patients) and the use of TL between 0 and 55%. Any reperfusion treatment (p-PCI or TL) was used in 37–93% of STEMI patients. Significantly less reperfusion therapy was used in those countries where TL was the dominant strategy. The number of p-PCI procedures per million per year varied among countries between 20 and 970. The mean population served by a single p-PCI centre varied between 0.3 and 7.4 million inhabitants. In those countries offering p-PCI services to the majority of their STEMI patients, this population varied between 0.3 and 1.1 million per centre. In-hospital mortality of all consecutive STEMI patients varied between 4.2 and 13.5%, for patients treated by TL between 3.5 and 14% and for patients treated by p-PCI between 2.7 and 8%. The time reported from symptom onset to the first medical contact (FMC) varied between 60 and 210 min, FMC-needle time for TL between 30 and 110 min, and FMC-balloon time for p-PCI between 60 and 177 min. Conclusion Most North, West, and Central European countries used p-PCI for the majority of their STEMI patients. The lack of organized p-PCI networks was associated with fewer patients overall receiving some form of reperfusion therapy.

Activated Partial Thromboplastin Time and Outcome After Thrombolytic Therapy for Acute Myocardial Infarction: Results From the Gusto-i Trial

BACKGROUND Although intravenous heparin is commonly used after thrombolytic therapy, few reports have addressed the relationship between the degree of anticoagulation and clinical outcomes. We examined the activated partial thromboplastin time (aPTT) in 29,656 patients in the Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO-I) trial and analyzed the relationship between the aPTT and both baseline patient characteristics and clinical outcomes. METHODS AND RESULTS Intravenous heparin was administered as a 5000-U bolus followed by an initial infusion of 1000 U/h, with dose adjustment to achieve a target aPTT of 60 to 85 seconds. aPTTs were collected 6, 12, and 24 hours after thrombolytic administration. Higher aPTT at 24 hours was strongly related to lower patient weight (P < .00001) as well as older age, female sex, and lack of cigarette smoking (all PT< .0001). At 12 hours, the aPTT associated with the lowest 30-day mortality, stroke, and bleeding rates was 50 to 70 seconds. There was an unexpected direct relationship between the aPTT and the risk of subsequent reinfarction. There was a clustering of reinfarction in the first 10 hours after discontinuation of intravenous heparin. CONCLUSIONS Although the relationship between aPTT and clinical outcome was confounded to some degree by the influence of baseline prognostic characteristics, aPTTs higher than 70 seconds were found to be associated with higher likelihood of mortality, stroke, bleeding, and reinfarction. These findings suggest that until proven otherwise, we should consider the aPTT range of 50 to 70 seconds as optimal with intravenous heparin after thrombolytic therapy.

Acute Coronary Syndromes in the GUSTO-IIb Trial Prognostic Insights and Impact of Recurrent Ischemia

Background—Recurrent ischemia after an acute coronary syndrome portends an unfavorable outcome and has major resource-use implications. This issue has not been studied systematically among the spectrum of patients with acute coronary presentations, encompassing those with and without ST-segment elevation. Methods and Results—We assessed the 1-year prognosis of the 12 142 patients enrolled in the GUSTO-IIb trial by the presence (n54125) or absence (n58001) of ST-segment elevation. This latter group was further categorized into those with baseline myocardial infarction (n53513) or unstable angina (n54488). We also assessed the incidence of recurrent ischemia and its impact on outcomes. Recurrent ischemia was significantly rarer in those with ST-segment elevation (23%) than in those without (35%; P,0.001). Mortality at 30 days was greater among patients with ST-segment elevation (6.1% versus 3.8%; P,0.001) but less so at 6 months; by 1 year, mortality did not differ significantly (9.6% versus 8.8%). Patients with non‐ST-segment-elevation infarction had higher rates of reinfarction at 6 months (9.8% versus 6.2%) and higher 6-month (8.8% versus 5.0%) and 1-year mortality rates (11.1% versus 7.0%) than such patients who had unstable angina. Conclusions—Refractory ischemia was associated with an approximate doubling of mortality among patients with ST-segment elevation and a near tripling of risk among those without ST elevation. This study highlights not only the substantial increase in late mortality and reinfarction with non‐ST-segment-elevation infarction but also the opportunities for better triage and application of therapeutic strategies for patients with recurrent ischemia. (Circulation. 1998;98:1860-1868.)

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.