SMILE: One-Stage PCI Superior for Non-STEMI and Multivessel CAD

In patients with multivessel CAD who experience non-STEMI, achieving complete revascularization in one-stage PCI produces better outcomes than does a multi-stage process, according to findings presented at TCT 2014.

For the SMILE trial, researchers led by Gennaro Sardella, MD, of Policlinico Umberto I, University of Rome in Italy, enrolled 500 non-STEMI patients slated to an early invasive strategy who had angiographic evidence of >70% diameter stenosis in multiple vessels. Patients were randomized to single-stage (n=253) or multistage PCI (n=247).

At 12 months, the rate of MACCE (primary outcome; all-cause death, reinfarction, rehospitalization for ACS, repeat revascularization or stroke) was lower in patients treated with one-stage PCI, as were rates of all-cause death, target vessel revascularization and bleeding (see Figure).

Bleeding differences early on

Early in the study period, the only significant difference between the two groups was bleeding, Sardella said. There were seven bleeding events in the multistage group (2.82%) vs. one in the one-stage group (0.39%; P=.01) during hospitalization but no additional bleeding events through 30 days.

All incidences of bleeding were minor to minimal, Sardella said, adding that a hypothesis for the increased bleeding in the multistage group is that the second procedure was more likely to be performed via transfemoral access rather than transradial access.

At 6 months, bleeding rates remained higher in the multistage group compared with the one-stage group (3.22% vs. 0.39%; P=.01), while the multistage group also had higher rates of MACCE (10.93% vs. 5.13%; P=.02) and all-cause death (7.69% vs. 3.16%; P=.02) compared with the one-stage group. 

There were also differences between the groups in levels of myocardial enzymes after PCI. At baseline, patients had similar levels of troponin and myoglobin. Patients in the one-stage group had lower levels of troponin compared with those in the multistage group after their first procedure (0.54 ± 0.96 vs. 0.95 ± 1.28; P<.0001), though myoglobin levels did not differ. The one-stage group had higher levels of myoglobin compared with patients in the multistage group after their second procedure (79.31 ± 129.73 vs. 59.81 ± 34.88; P=.0230) but similar troponin level. CK-MB levels were equivalent between the two strategies both at baseline and after PCI.

Noncardiac death drove results

In SMILE, “the superiority of one-staged complete coronary revascularization in terms of major events is mainly due to the unexplained higher incidence of noncardiac death,” Sardella noted, adding that trial investigators do not yet have a hypothesis to explain the disparity.

Sardella said that he and his colleagues undertook the current study because there is little to no guidance from U.S. and European professional societies on whether patients with non-STEMI and multivessel CAD should have all vessels treated simultaneously, or whether nonculprit lesions should be treated on an ad hoc basis.

Disclosures: 

• Sardella reports receiving consultant fees/honoraria from Alvimedica, AstraZeneca, Biosensors, Boston Scientific and Terumo Medical.