The Acute Myocardial Infarction STudy of ADenosine (AMISTAD) trial was designed to test the hypothesis that adenosine as an adjunct to thrombolysis would reduce myocardial infarct size.
Reperfusion ...therapy for acute myocardial infarction (MI) has been shown to reduce mortality, but reperfusion itself also may have deleterious effects.
The AMISTAD trial was a prospective, open-label trial of thrombolysis with randomization to adenosine or placebo in 236 patients within 6 h of infarction onset. The primary end point was infarct size as determined by Tc-99 m sestamibi single-photon emission computed tomography (SPECT) imaging 6+/-1 days after enrollment based on multivariable regression modeling to adjust for covariates. Secondary end points were myocardial salvage index and a composite of in-hospital clinical outcomes (death, reinfarction, shock, congestive heart failure or stroke).
In all, 236 patients were enrolled. Final infarct size was assessed in 197 (83%) patients. There was a 33% relative reduction in infarct size (p = 0.03) with adenosine. There was a 67% relative reduction in infarct size in patients with anterior infarction (15% in the adenosine group vs. 45.5% in the placebo group) but no reduction in patients with infarcts located elsewhere (11.5% for both groups). Patients randomized to adenosine tended to reach the composite clinical end point more often than those assigned to placebo (22% vs. 16%; odds ratio, 1.43; 95% confidence interval, 0.71 to 2.89).
Many agents thought to attenuate reperfusion injury have been unsuccessful in clinical investigation. In this study, adenosine resulted in a significant reduction in infarct size. These data support the need for a large clinical outcome trial.
The acute decompensated heart failure (ADHF) is not as well characterized as the chronic phase, particularly in Latin American countries. Thus, the aim of this overview was to describe the clinical ...profile, treatment, and inhospital course of ADHF during the last decade in Argentina.
Results obtained from 5 Argentinean prospective and multicenter registries, involving 2974 patients admitted for ADHF, were assessed. These registries were performed and published between 1992 and 2004.
The mean age was 65 to 70 years, and nearly 40% were female. Coronary artery disease was the main etiology in nearly 30% of the patients. Between 1992 and 2004, the use of angiotensin-converting enzyme inhibitors increased from 29.9% to 53.4% before admission and from 48.5% to 69.3% before discharge; the use of β-blockers rose from 4.2% to 33.2% at admission and from 2.5% to 42.4% at predischarge (all
P < .0001). Inhospital mortality rates in the first to the fifth registries were 12.1%, 4.6%, 10.5%, 8.9%, and 4.7% (
P trend = .006). However, there were 98 (7.7%) deaths among 1272 patients before 2002, compared with 129 (7.6%) among 1702 since 2002 (
P = .9).
The clinical profile of this largest sample of ADHF reported from a Latin American country is different from that observed in clinical trials and comparable to registries worldwide. Although an improvement in the use of recommended drugs was observed in the last decade, the average mortality has not changed. These findings might have implications in the design of multinational clinical trials.
The outcome of patients who fail to reperfuse with thrombolytic therapy or percutaneous coronary intervention (PCI) for ST-elevation acute myocardial infarction (STEMI) may be improved with ...additional pharmacologic and mechanical interventions such as rescue PCI or intravenous glycoprotein IIb/IIIa infusion. The standard 12-lead ECG is the most commonly available and suitable tool for routine bedside evaluation of the success of reperfusion therapy for STEMI. This article reviews and discusses the current data on the four ECG markers for prediction of the perfusion status of the ischemic myocardium: ST-segment deviation, T-wave configuration, QRS changes, and reperfusion arrhythmias.
ST-segment depression (ST-D) on the admission electrocardiogram of patients with non-ST-elevation acute coronary syndromes (NSTEACSs) is associated with higher mortality. However, few studies have ...evaluated the effect of location of ST-D and T-wave polarity on long-term prognosis of patients with NSTEACS. Electrocardiographic (ECG) and clinical data from 6,770 patients with NSTEACS randomly assigned in the Global Use of Strategies to Open Occluded Coronary Arteries (GUSTO) IIB trial were analyzed retrospectively. One-year mortality was correlated with location of ST-D (leads I and aVL; II, III, and aVF; V1 to V3; or V4 to V6) and T-wave polarity. ST-D in any of the ECG locations was associated with higher mortality compared with patients without ST-D. Patients with ST-D and T-wave inversion in leads V4 to V6 had the highest 1-year mortality rate of all groups (16.2%), significantly higher compared with patients with ST-D without T-wave inversion in those leads (9.0%, p=0.001). Logistic regression analysis showed that age, hyperlipidemia, Killip class>I, history of myocardial infarction, history of heart failure, history of angina pectoris, systolic blood pressure, heart rate, sum of ST-D (odds ratio 1.061, 95% confidence interval 1.035 to 1.087, p<0.001), and ST-D with T-wave inversion in leads V4 to V6 (odds ratio 1.374, 95% CI 1.023 to 1.844, p=0.035) were independent predictors of 1-year mortality. Conversely, ST-D without T-wave inversion in leads V4 to V6 or other ECG presentations were not independent predictors of high 1-year mortality. In conclusion, ST-D with T-wave inversion in leads V4 to V6 on the admission electrocardiogram in patients with NSTEACS identifies those with higher 1-year mortality than for patients with any other ECG presentation.
Arrhythmias play a significant role in the mortality and morbidity as well as hospitalizations of patients who carry a diagnosis of congestive heart failure. With improving survival in a world of ...novel medications and devices, an understanding of the pathophysiology and management of these arrhythmias is crucial. Majority of the basic heart failure medications such as beta- -blockers, angiotensin converting enzyme inhibitors/aldosterone receptor blockers and aldosterone antagonists play a pivotal role in prevention of sudden cardiac deaths which can be a direct/indirect result of these arrhythmias. Anti-arrhythmic drugs and implantable cardioverter-defibrillators were also beneficial in selected patients. Innovative electrophysiological techniques need to be considered in special situations.
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