The trial, presented today at the European Society of Cardiology Congress 2007, enrolled 600 STEMI patients under 75 years old within 12 hours of symptom onset who had been admitted to hospitals without PCI facilities. They all received half-dose lytic therapy (reteplase), aspirin, heparin, and abciximab bolus plus infusion and were then randomized to two groups: immediate transfer for PCI; or transfer for PCI only if they had persistent ST elevation at 90 minutes (rescue PCI). The median time from reteplase to angiography was 136 minutes in the immediate-transfer group and 212 minutes in those patients sent for rescue PCI (36% of group 2).

Results showed a significantly better outcome in the immediate-transfer group, with a large reduction in the primary outcome of death/MI/refractory ischemia at 30 days.

All components of the primary end point trended toward benefit in the PCI-for-all group, but the main driver of the better outcome was refractory ischemia.

In terms of safety, there was an increase in bleeding rate in the PCI-for-all group, and stroke and transfusions were nonsignificantly increased.

Presenting the data, Dr Carlo Di Mario (Brompton Hospital, London, UK) said this study suggested that facilitated PCI was feasible and that these results may have been better than other trials, as it included a potent antiplatelet agent (abciximab) so that platelets are inactivated at the time of PCI. But he added that the bleeding results may have looked reassuring, as patients over 75 years of age were excluded.

But discussant for the trial at the hotline session, Dr Freek Verheugt (Nijmegen University, the Netherlands), said this trial should not be thought of as a facilitated-PCI study, as there was no direct-PCI comparison arm. Rather, it should be viewed as another study suggesting that in patients given lysis for whatever reason, immediate transfer for PCI was probably beneficial. He explained that until a few years ago, the strategy of immediate PCI after lysis had not been successful, but with the more extensive use of stents, more recent studies (GRACIA, CAPITAL, and SIAM-3) have shown better results with this approach.

On specific issues regarding CARESS, Verheugt pointed out that clopidogrel was not given at the time of lysis in this study (but was given at the time of PCI), and he said he would like to see the results in patients who had reperfused on the lytic therapy, which were not presented. He also said more information was needed as to the optimal time to perform PCI after lysis, noting that this had varied from two to 17 hours in the current four trials suggesting benefit of this approach.

Chair of the hotline session, Dr Christian Hamm (University Hospital Eppendorf, Hamburg, Germany), commented to heartwire that this was a relatively small trial, so the results should be interpreted with caution. He also pointed out that the half-dose reteplase and abciximab regimen had not been shown to be the best treatment for STEMI in other studies evaluating lytic treatment and that CARESS cannot be compared with the larger FINESSE facilitated-PCI trial (presented at the same session today), as CARESS did not have a primary-PCI arm. "This trial is suggesting that in patients who cannot get to PCI within 120 minutes, when a lysis strategy is chosen, immediate transfer to PCI may be warranted. But it did not investigate whether transfer to PCI without lytic would have been preferable, which the FINESSE results actually suggest," he added.

Verheugt also emphasized the difference between CARESS and FINESSE. "FINESSE was a primary-PCI trial looking at whether can we improve upon primary PCI by pretreatment with a drug. CARESS was a lytic-oriented trial—it gave a lytic to all and looked at whether further intervention was beneficial. That's a very different trial," he told heartwire.