Outcomes of Primary Percutaneous Coronary Intervention in ST-Segment Elevation Myocardial Infarction Patients With Previous Coronary Bypass Surgery

Selected in JACC Cardiovascular Interventions by A. Al-Riyami

References

Authors

LP. Kohl, RF. Garberich, H. Yang, SW. Sharkey, MN. Burke, DL. Lips, DA. Hildebrandt, DM. Larson, TD. Henry

Reference

J Am Coll Cardiol Intv. 2014;7(9):981-987

Published

September 2014

Link

Access the Abstract

My Comment

What we know

Previous studies showed that previous CABG to be an independent risk factor for adverse clinical outcomes in patients presenting with STEMI. However, these studies and analyses were done in the fibrinolysis era. The authors of this study sought to determine the outcome of patients with previous CABG who presented with STEMI and treated with primary PCI and contemporary therapies.

Major Findings

  • Using a prospective database from The Minneapolis Heart Institute of 3,542 consecutive patients treated as part an MI regional STEMI program from March 4, 2003 through April 22, 2012 were analysed.
  • Patients with previous CABG were stratified to 3 groups by culprit lesion based on ECG and angiographic findings: 1st SVG culprit - 2nd native vessel culprit  or 3rd no clear culprit.
  • 249 (7%) out of the 3,542 patients had a history of previous CABG.
  • There were significant differences between the group with previous CABG compared to those without in several aspects including older age, prevalence of more cardiac risk factors and history of MI. On the other hand, those with previous CABG had less anterior MI because of the presence of an IMA graft to the LAD.
  • Patients with previous CABG had less primary PCI treatment compared to those without, (67.5% vs 79.8%, p < 0.001) respectively.
  • There was no significant difference in median length of stay or in-hospital death. MACE at 30 days (including stroke, recurrent infarction, recurrent ischemia, or death). The rates of hospital readmission at 30 days for cardiac causes were equivalent in the 2 groups.
  • There was no difference in mortality at 1 year, but there was higher mortality in the CABG group at 5 years (24.9% vs. 14.2%, p < 0.001).
  • In the CABG group the culprit lesion was an SVG 34% of the time, native vessel 42% of the time, no clear culprit in 24% of the time and 1% had both native and SVG co-culprit lesions.
  • LIMA was not identified as the culprit in any case.
  • SVG occlusion compared to native vessel occlusion resulted in more presentation with pre-PCI shock (14.3% vs. 4.8%, p 0.038), lower TIMI grade flow pre- and post-PCI (TIMI 2/3 43.4% vs. 52.0% and 92.8% vs. 98.0% respectively).
  • There was no difference in in-hospital mortality: 8.3% vs. 3.9%, p 0.19; 1-year mortality: 14.3% vs. 9.6%, p 0.35) between SVG or native culprit. There were no differences in length of stay, readmission for cardiac causes or MACE at 30 days.

My comments

It goes without saying that patients who have had CABG are a higher risk group to start with; that is why they got CABG in the first place. For these patients to have worse outcomes compared to those without CABG would be expected. However, this large prospective database shows that despite that fact the in-hospital mortality and 1-year mortality is similar in these two groups. This is likely due to the timely primary PCI that these patients get and the intensive medical therapy they are subjected to. The interesting thing in this study as well is the fact that the LIMA was not identified as a culprit in any patient, attesting to the fact that IMA is such a good bypass graft and should always be used.

1 comment

  • Afsaneh Mohamadi 21 Nov 2014

    Hi , the study results were surprising,especially similar 1year outcome despite lower TIMI flow. I would like to know more about intervention details in bypass group.