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In the treatment of acute myocardial infarction, delayed reperfusion therapy is associated with increased mortality. Predictors of delay have been described for fibrinolysis but not for primary percutaneous transluminal coronary angioplasty (pPTCA). Therefore, we studied 40,017 consecutive patients with acute myocardial infarction who underwent pPTCA in the National Registry of Myocardial Infarction between June 1994 and April 2000. Median door-to-balloon times were calculated, and factors independently associated with a delay of >120 minutes were determined by logistic regression. The median door-to-balloon time among all patients was 111 minutes (interquartile range 84 to 152). The proportion of patients with a delay of >2 hours was greater among those aged ≥65 years (49% vs 41%), women (50% vs 42%), patients with contraindications to fibrinolysis (60% vs 41%), and those without chest pain on admission (61% vs 43%, all p <0.0001). Delay was also more common with transfer from another hospital (87% vs 38%), with presentation outside the hours of 8 a.m. to 4 p.m. (51% vs 38%), and in hospitals performing <49 pPTCAs/year (47% vs 41%, all p <0.0001). The strongest independent predictor of delay was hospital transfer, along with non-daytime presentation and low-volume centers. Older age, female sex, and non-white race were weaker predictors. Both patient and hospital factors are associated with delay in pPTCA after presentation. These findings may help design treatment algorithms to minimize delay, thus improving the survival benefit of pPTCA. These results may also help design trials of combination reperfusion strategies. [Copyright &y& Elsevier]

The results of the ASsessment of Safety and Efficacy of a New Thrombolytic agent (ASSENT-2) trial revealed that tenecteplase (TNK) is equivalent to tissue plasminogen activator (t-PA) for treating myocardial infarction. Because careful consideration of safety is important with all agents, including the newer bolus therapies, and across a range of doses, this study evaluated the safety of TNK compared with t-PA across a range of weight and dose categories. The 5 doses of TNK ranged from 30 to 50 mg and were adjusted for estimated weight. Rates of death and intracranial hemorrhage were determined among patients receiving TNK and t-PA in ASSENT-2, stratified by categories of estimated weight corresponding to each TNK dose. Respective rates of death with TNK versus t-PA were not significantly different in any estimated weight category: <60 kg (12.54% vs 11.46%), 60 to 69 kg (8.22% vs. 8.97%), 70 to 79 kg (5.57% vs 5.48%), 80 to 89 kg (4.66% vs 5.36%), and > or =90 kg (4.91% vs. 3.96%, all p > or =0.26). Respective rates of intracranial hemorrhage were also not significantly different: <60 kg (2.20% vs. 2.29%), 60 to 69 kg (0.97% vs. 1.33%), 70 to 79 kg (1.15% vs. 1.10%), 80 to 89 kg (0.73% vs 0.49%), and > or =90 kg (0.47% vs 0.47%, all p > or =0.33). Adjustment for small baseline differences in this randomized sample did not change the results. Thus, across the range of estimated weight categories corresponding to each TNK dose, TNK is as safe and effective as t-PA. [ABSTRACT FROM AUTHOR]

In a retrospective cohort of patients treated in community hospitals, tissue plasminogen activator (t-PA) was associated with decreased odds of in-hospital death or nonfatal stroke. However, the relative benefit was less evident in older patients and women, and some older subgroups did not benefit from treatment. [ABSTRACT FROM AUTHOR]

Since the introduction of reperfusion therapy in the early 1980s, cardiologists have largely focused on coronary artery flow and diameter, with the goal being to restore normal epicardial artery perfusion and large lumens. For many years, epicardial coronary flow has been simply assessed by the TIMI (thrombolysis in myocardial infarction) flow grade. This semiquantitative coronary angiographic tool places a patient's coronary flow into one of four different categories and has been shown to be associated with mortality. The corrected TIMI frame count provides a more objective quantitative index of coronary flow and has been shown to segregate even TIMI grade 3 flow into lower and higher risk subgroups.