A case-cohort study of postoperative myocardial infarction: impact of anemia and cardioprotective medications.

Abstract

OBJECTIVE:

Postoperative myocardial infarction (poMI) is a serious and costly complication. Multiple risk factors for poMI are known, but the effect of anemia and cardioprotective medications have not been defined in real-world surgical practice.

METHODS:

Patients undergoing inpatient elective surgery were assessed at 17 hospitals from 2008 to 2011 for the occurrence of poMI (American Heart Association definition). Non-MI control patients were chosen randomly on the basis of case type. Descriptive, univariable, and multivariable statistical analysis were performed for primary outcomes of poMI and death at 30 days.

RESULTS:

Compared with controls (N = 304), patients with poMI (N = 222) were older (72 ± 11 vs 60 ± 17 years, P < .0001), had a lesser preoperative hematocrit (37 ± 6 vs 39 ± 5, P < .0001), more often were smokers, had a preoperative T-wave abnormality (21% vs 9%, P < .0001), and had a preoperative stress test with a fixed deficit (26% vs 3%; P < .001). Preoperative factors associated with poMI included peripheral vascular disease (odds ratio 2.6; 95% confidence interval 1.3-5.3), tobacco use (1.7; 1.01-2.9), history of percutaneous coronary angioplasty (2.8; 1.6-5.0), and age (1.05; 1.03-1.07), whereas hematocrit >35 (0.51; 0.32-0.82) and preoperative acetylsalicylic acid, ie, aspirin (0.59; 0.4-0.97) were protective. Preoperative β-blockade, statin, and use of angiotensin-converting enzyme inhibitors were not associated with lesser rates of poMI. Non-MI complication rates were 23-fold greater in the poMI group compared with the control group (P < .0001). Mortality with poMI within 30 days was 11% compared with 0.3% in non-MI control patients (P < .0001). In patients with poMI, factors independently associated with death included use of epidurals (3.5; 1.07-11.4) and bleeding (4.2; 1.1-16), whereas preoperative use of aspirin (0.29; 0.1-0.88), and postoperative β-blockade (0.18; 0.05-0.63) were protective. Cardiac catheterization, percutaneous coronary intervention, or coronary artery bypass grafting after poMI was performed in 34% of those alive and 20% of those who died (P = .16).

CONCLUSION:

In the current era, poMI patients have a markedly increased risk of death. This risk is decreased with preoperative use of acetylsalicylic acid and post MI β-blockade. Further study is warranted to explore the role of anemia and cardiac interventions after poMI.

• Authors: Peter K Henke, Grettel Zamora-Berridi, Michael J Englesbe, Shijie Cai, Linda Brooks, Ellen McKeown, Laurel Phillips, Wei Lau, Darrell C Campbell
• Journal: Surgery (Surgery) Vol. 156 Issue 4 Pg. 1018-26, 1029 (Oct 2014) ISSN: 1532-7361 [Electronic] United States
• PMID: 25239363 (Publication Type: Evaluation Study, Journal Article, Multicenter Study)
• Copyright: Copyright © 2014 Elsevier Inc. All rights reserved.

Chemical References

• Adrenergic beta-Antagonists
• Cardiotonic Agents
• Aspirin

Topics

• Adrenergic beta-Antagonists (therapeutic use)
• Adult
• Aged
• Aged, 80 and over
• Anemia (complications)
• Aspirin (therapeutic use)
• Cardiotonic Agents (therapeutic use)
• Case-Control Studies
• Female
• Humans
• Logistic Models
• Male
• Middle Aged
• Multivariate Analysis
• Myocardial Infarction (etiology, mortality, prevention & control)
• Postoperative Care (methods)
• Postoperative Complications (etiology, mortality, prevention & control)
• Preoperative Care (methods)
• Retrospective Studies
• Risk Factors