No Benefit from Late Invasive Therapy for Occluded Arteries

A third of patients hospitalized with an acute myocardial infarction (MI) have persistent occlusion of the infarct related artery at 72 hours, despite the availability of several effective reperfusion strategies. This has led to interest as to whether some of the benefits seen with early opening of the artery could be achieved with later opening, the so called ‘Open Artery Hypothesis’. It is thought that late opening of occluded infarct related arteries after acute MI may improve survival (through lower risks of heart failure and sudden death from cardiac causes), ventricular function (revascularization of hibernating myocardium and improved remodeling) and quality of life. In order to assess this hypothesis, the Occluded Artery Trial (OAT) compared PCI with medical therapy alone in 2166 patients who had an occluded infarct related artery 3-28 days after a MI, finding no evidence of benefit from late arterial opening. This paper reports the quality of life and economic outcomes associated with the use of such a strategy.

951 patients (44% of those eligible) underwent quality of life assessment using a panel of tests including 2 principal outcome measures, the Duke Activity Status Index (DASI) for cardiac physical function (higher scores indicating better function) and the Medical Outcomes Study 36 item Short Form Health Inventory 5 which measures psychological well-being. Structured interviews were performed at baseline, 4, 12 and 24 months. Costs of treatments were assessed for 458/469 patients in the United States (98%) and 2 year cost effectiveness estimated.

At 4 months the medical therapy group, when compared to the PCI group, had a clinically marginal decrease of 3.4 points in the DASI score (p=0.007). At 1 and 2 years the differences were smaller. No significant differences in psychological well-being were observed. For the 469 patients in the United States, cumulative 2 year costs were approximately $7000 higher in the PCI group (p<0.001) and the quality adjusted survival was marginally longer in the medical therapy group. When combined with previously reported lack of advantage of PCI with respect to the primary end point of the OAT trial, these data do not support the practice of routine PCI in patients with stable condition and an occluded infarct related artery after myocardial infarction. The analysis of lifetime cost effectiveness in the COURAGE trial had similar results with an estimated cost / additional QALY with PCI OF $168,000. However it should be remembered that there was a significant cross-over from the medical therapy arm subsequently requiring intervention.

  • Mark DB, Pan W, Clapp-Channing NE et al. Quality of Life after Late Invasive Therapy for Occluded Arteries. N Engl J Med 2009;360:774-83

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