Cardiac bypass surgery in acute myocardial infarction is not associated with higher mortality

Objective: Indication for bypass surgery in acute infarction is considered to be borderline, as mortality seems to be inacceptable high. Studies targeting only on the time interval post infarction showing a 30 day mortality of more than 15% within the first 24h after infarction. On contrast to clinical routine, American College of Cardiology guidelines demand early revascularisation in acute infarction and immediate during cardiogenic shock.

Methods: From January to December 2005 119 pts. out of a total number of 3000 open heart operations were operated in our hospital due to acute myocardial infarction (<24h). Retrospective data analysis was performed.

Results: Overall 30 day mortality was 10%. There was no mortality in patients without preoperative cardiogenic shock (=79), but 30% mortality (n=12) in shock (n=40). Risk analysis showed preoperative cardiogenic shock and very low ejection fraction as significant factor for mortality, but not age, enzymes and time interval after infarction. In addition, immediate implantation of intraaortic ballon pump (IABP) preoperatively in cardiogenic shock significantly reduced perioperative mortality (11 vs. 83%).

Conclusion: As a result of this, revascularisation in acute myocardial infarction has to be as soon as possible to prevent patients developing cardiogenic shock. Patients with evolving or manifest cardiogenic shock necessitate preoperative IABP-support immediately after diagnosis. This reduces perioperative mortality to an elevated, but acceptable range. Postponing cardiac surgery due to acute myocardial infarction seems to be irrational.