Association of beta-blocker therapy
 at discharge with clinical outcomes 
in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

Selected in JACC Cardiovascular Interventions by A. Al-Riyami

References

Authors

Jeong Hoon Yang, Joo-Yong Hahn, Young Bin Song,
 Seung-Hyuk Choi, Jin-Ho Choi, Sang Hoon Lee, Joo Han Kim, Young-Keun Ahn, Myung-Ho Jeong, Dong-Joo Choi, 
Jong Seon Park, Young Jo Kim, Hun Sik Park, Kyoo-Rok Han, Seung Woon Rha, Hyeon-Cheol Gwon

Reference

JACC Cardiovasc Interv. 2014 Jun;7(6):592-601

Published

June 2014

Link

Access the article

My Comment

What we know

The evidence behind the long-term use of beta blockers in patients with myocardial infarction stem largely from trials prior to reperfusion therapy and some with fibrinolytic therapy. Whether the same benefit of beta blocker (BB) therapy is seen with primary PCI, especially in patients with preserved LV function (EF > 40%) is not very clear.

Major Findings

  • 8,510 consecutive patients with ST elevation MI or new LBBB who underwent PCI, out of 20,344 patients enrolled in two large Korean registries of Myocardial Infarctions (KAMIR & KorMI).
  • Subjects were divided by use of beta-blockers at discharge into the beta-blocker (BB, n=6,873) group and no–beta-blocker (no-BB, n=1,637) group.
  • Propensity scores were estimated using multiple logistic-regression analysis that included multiple clinical risk factors and angiographic and procedural characteristics.
  • The no-BB patients were sicker than those discharged on BB; they were older, had prior MI, lower EF, renal dysfunction and post-procedural TIMI 0-1 flow.
  • 1,325 propensity-score-matched triplets of patients (2:1 BB vs no-BB) were created.
  • During 1-year follow up (367 days) the all cause mortality and cardiac mortality in the overall population were higher in the no-BB group compared with BB group; 3.6% vs 2.1% and 2.4% vs 1.1% respectively. There was no difference in myocardial infarction or coronary revascularisation.
  • Similar effects were seen in the propensity matched groups, with BB group having less adverse events than the no-BB group.
  • The protective effects of BB were also seen in all subgroups studied including those with LVEF > 40% and those with single vessel disease.

My Comments

Although widely practiced, the use of beta-blockers post primary PCI has very little contemporary evidence. However, the theoretical advantages of their use in this situation compel us to use it as part of optimal medical therapy (OMT).

The current study from Korea draws its strength from the large sample size and the fact that the data is collected prospectively.

It is worth noting, however, the fact that patients not prescribed beta-blockers were sicker to start which might explain their worse outcome. The propensity matching tries to correct this and the result favors the use of beta-blockers in post STEMI patients treated with primary PCI. How well can propensity matching correct for possible confounders is subject to contention, but until a randomized controlled trial is carried out to answer this particular question (I doubt it will ever be done), this is the best evidence we have.

Bottom line: all MI patients should receive beta-blockers, if possible.

2 comments

  • roberto larghi 02 Aug 2014

    How long should receive beta-blocker therapy post myocardial infarction

  • Amador Mena 05 Aug 2014

    I think that paper, support my management in tris Patient's group. Is Difficult to decide Whats the Better: ARA II /IECA VS BB, in some patients, when the blood presión is'not good. Due medications is the Better. Dr.. Eduardo Amador Mexico, D. F. Hospital Angeles del Pedregal.