This long-term follow-up of the original OAT trial has evaluated 2201 patients with an occluded infarct related artery (IRA) > 24 hours randomized to optimal medical treatment (MED) or optimal medical treatment and PCI (PCI) at a median follow-up of 6 years (max 9 years). All patients had an ejection fraction <50% and a proximal occlusion of a large vessel. Patients with severe inducible ischemia, angina at rest, class III or IV heart failure or significant left main or 3-vessel disease were excluded. The results confirm the original OAT findings: no difference in the primary endpoint (composite of death, myocardial infarction or class IV heart failure) between MED and PCI groups. These observations were confirmed even after subgroup analyses. The difference in angina rates observed through the first period of follow-up became non significant at 3 and 5 years. There was a trend towards a higher PCI rate in MED patients at 7 years. The authors conclude that there is robust evidence for no reduction of long-term rates of clinical events after routine PCI in stable patients with a totally occluded IRA and without severe inducible ischemia in the subacute phase after a myocardial infarction (MI).
Comment by Jacopo Oreglia:
It is better to have an open or occluded coronary artery? Obviously an open one! Well, this doesn’t look so true when this artery has been occluded for more than one day, as the OAT trial (and now this OAT long term follow-up) has taught to us. But let’s analyse the findings of this report.
First we have to keep in mind that these results apply only to definitely stable patients, identified as those with no post-MI angina, no inducible ischemia, no heart failure, no significant 3-vessel/ LM disease. A recent MI should not deserve PCI if meeting these criteria, according to OAT. Nevertheless, although this trial is elegant and leads to strong results, it has some limits.
Up to 20% of patients did not consent a longer follow-up and were thus lost at follow-up. Furthermore the large majority of PCI patients received bare metal stents (BMS), this may blunt the possible advantage of PCI over MED if drug eluting stents (DES) were used in large-scale. Finally dual antiplatelet therapy (DAPT) was continued for a median of 4 months, and only rarely up to one year as suggested by the 2009 ACC/AHA guidelines. These observation translate into a question: in the era of DES and prolonged DAPT for acute coronary syndromes, may the results of the OAT trial not be the same? Of course there is, at present, no definite answer. For sure the enormous advantages of early PCI in the setting of an acute MI or those of an ischemia driven PCI after subacute MI do not exist in the case of stable post-MI patients. No advantage of PCI over MED in this group of patients has been demonstrated. However a careful evaluation of the patients clinical and angiographic characteristics should always be done to drive the therapeutic strategy. An old fragile patient with a large thrombus burden and complex coronary anatomy is different form a young healthy one with focal occlusion of a proximal vessel, even if both are quite stable, post-MI patients. Common sense must be integrated in evidence based medicine, always.