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RESEARCH PRODUCT

Reperfusion Treatment in an Acute Myocardial Infarction in Patients Older Than 75 Years. Do We Need a Randomized Controlled Trial?

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Fibrinolytic therapy in ST-segment elevation acute myocardial infarction (AMI) constitutes one of the most important advances in cardiology in the last 25 years and has influenced the management and evolution of patients as much as the first coronary care units did. The most important limitations of fibrinolytics are the presence of absolute or relative contraindications to their administration in ≤25% of patients, their limited capacity to restore adequate coronary flow and the risk of inducing cerebral hemorrhage. They are at their most efficient in the first 2 hours’ evolution of AMI but lose their efficacy thereafter. 1 Consequently, treatment must be initiated as early as possible and always within 30 minutes of indication. In contrast, primary percutaneous coronary intervention (PCI) has few contraindications, greater capacity to restore adequate coronary flow and is less time-dependent. The meta-analysis of 23 trials comparing PCI with thrombolysis shows that, if patients in cardiogenic shock are excluded, primary PCI reduces 1-month mortality from 7% to 5% (odds ratio [OR]=0.70; 95% confidence interval [CI], 0.58-0.85) and the combined outcome of mortality, reinfarction or stroke from 14% to 8% (OR=0.53; 95% CI, 0.450.63). 2 Consequently, PCI is currently the reperfusion treatment of choice for most patients with AMI. However, these results pertain to centers with a great deal of experience of PCI and volume of patients has been shown to be inversely proportionate to mortality. So, PCI is only recommended in centers that perform many such interventions per year. Moreover, although the timing of interventions may not be crucial, as it is with thrombolysis, it is still important: it is estimated that mortality increases by 8% for every 30 minutes’ delay in intervention following the onset of symptoms. Consequently, PCI cannot be expected to be preferred to thrombolysis in the first 2 hours’ evolution, in patients with small infarctions, when anticipated time-to-procedure may be >60 min greater than for thrombolysis (door-to-dilatation time >90 min) or in centers that perform few interventions per year. Clinical practice guideline recommendations clearly specify that PCI is the therapeutic option of choice when it can be performed in <90 min by an experienced team.