Coronary Angiography in Patients With Perioperative Myocardial Injury After Non-Cardiac Surgery

Abstract: Each year, more than 300 million patients worldwide undergo non-cardiac surgery. Perioperative myocardial infarction (MI) is a common cardiovascular complication of surgery; thus, we sought to determine coronary artery anatomy in patients referred for coronary angiography for the evaluation of perioperative MI after non-cardiac surgery.

J INVASIVE CARDIOL 2018;30(9):E90-E92.

Key words: complications, non-cardiac surgery, research letter

Each year, more than 300 million patients worldwide undergo non-cardiac surgery.¹ Perioperative myocardial infarction (MI) is a common cardiovascular complication of surgery that can occur in up to 5.0% of patients with increased baseline cardiovascular risk.^2,3 Perioperative MI is strongly associated with in-hospital and long-term mortality.^4,5 Although mechanisms of perioperative MI have not been fully characterized, MI can be attributed to either unstable coronary artery disease (CAD) (type 1 MI) or to a mismatch in myocardial oxygen supply and demand in the setting of stable CAD (type 2 MI). In order to determine the optimal treatment of perioperative MI, data on the prevalence of CAD in these patients are necessary. Thus, we sought to determine coronary artery anatomy in patients referred for coronary angiography for the evaluation of perioperative MI after non-cardiac surgery.

Methods

Patients with perioperative MI or myocardial injury after non-cardiac surgery who were referred for coronary angiography after non-cardiac surgery at NYU Langone Medical Center from January 1, 2013 to December 31, 2015 were retrospectively identified. MI was defined according to the Third Universal Definition of MI, based on a rise and fall in cardiac troponin I above the 99% upper reference limit of the assay in conjunction with evidence of ischemia, including symptoms, electrocardiographic changes, or imaging evidence of a new wall-motion abnormality.⁶Myocardial injury was defined as a rise and fall in troponin without clinical evidence of ischemia. Demographic, clinical, and angiographic characteristics were obtained via medical record review. Obstructive CAD was defined as any major epicardial vessel with any ≥70% angiographic diameter stenosis. Continuous variables were compared with the independent samples Student’s T-test or the Mann-Whitney U-tests and categorical variables were compared with Chi-square or Fisher’s exact tests. A P-value <.05 was considered significant for all tests. All analyses were performed using SPSS 20 (IBM Corporation).

Results

A total of 31 patients with perioperative MI (n = 28) or myocardial injury (MINS; n = 3) after non-cardiac surgery were referred for invasive coronary angiography. The mean age was 70 ± 10 years, 52% were male, and 87% were white, and cardiovascular risk factors were common. Full demographic and clinical characteristics are shown in Table 1. Orthopedic (39%) and vascular surgeries (26%) were the most common non-cardiac surgical procedures provoking the cardiovascular event. At the time of coronary angiography, obstructive CAD was identified in 24 patients (77.4%) and 15 patients (48.4%) underwent percutaneous coronary intervention. Chronic total occlusion of a major epicardial vessel was identified in 11 patients with obstructive CAD. Among patients without obstructive CAD, angiography revealed mild CAD (stenosis <40% in major epicardial coronary vessels) in the majority of cases (71.4%). Angiographically normal coronary arteries were present in 1 case. Severe aortic stenosis was identified in 2 cases (28.6%) without obstructive CAD. In comparison to patients with obstructive CAD, patients with non-obstructive CAD at angiography were less likely to have a history of hypertension and had lower left ventricular ejection fraction by echocardiography in the perioperative period (Table 1). 

Discussion

In this retrospective study of patients undergoing coronary angiography for perioperative MI or MINS complicating non-cardiac surgery, obstructive CAD was present in the majority of cases, with chronic total occlusions in nearly one-half of these patients. Percutaneous coronary intervention was performed in 48% of cases. Nearly one-quarter of patients did not have obstructive coronary disease; the mechanism of perioperative events in this population is unknown. Possible etiologies of MINS or MI with non-obstructive CAD may include transient coronary vasospasm, microvascular dysfunction or small vessel disease, Takotsubo cardiomyopathy, or occult myocarditis.⁷ Still, given the predominance of CAD in this cohort, the present study reaffirms the wisdom of empiric guideline-directed medical therapy for atherosclerotic cardiovascular disease in these patients, despite limited evidence from clinical trials in this population.^8,9

Study limitations. There are a few limitations of the present analysis. First, only patients referred for invasive angiography were included in the present analysis and a selection bias favors inclusion of patients with the greatest likelihood of obstructive CAD. In comparison to a larger retrospective study of perioperative MI,¹⁰ non-obstructive disease was less common in the present cohort (22.6% vs 53.9%), perhaps due to differences in coronary angiography referral patterns after perioperative MI and MINS. Ultimately, larger studies examining the prevalence of obstructive CAD in patients with perioperative cardiovascular events as well as efforts to identify novel markers of increased perioperative cardiovascular risk are warranted. 

References

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2.    Smilowitz NR, Gupta N, Ramakrishna H, Guo Y, Berger JS, Bangalore S. Perioperative major adverse cardiovascular and cerebrovascular events associated with non-cardiac surgery. JAMA Cardiol. 2017;2:181-187.

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4.    Smilowitz NR, Gupta N, Guo Y, Berger JS, Bangalore S. Perioperative acute myocardial infarction associated with non-cardiac surgery. Eur Heart J. 2017;38:2409-2417.

5.    Botto F, Alonso-Coello P, Chan MT, et al. Myocardial injury after noncardiac surgery: a large, international, prospective cohort study establishing diagnostic criteria, characteristics, predictors, and 30-day outcomes. Anesthesiology. 2014;120:564-578.

6.    Thygesen K, Alpert JS, Jaffe AS, et al. Third universal definition of myocardial infarction. J Am Coll Cardiol. 2012;60:1581-1598.

7.    Agewall S, Beltrame JF, Reynolds HR, et al. ESC working group position paper on myocardial infarction with non-obstructive coronary arteries. Eur Heart J. 2017;38:143-153.

8.    Amsterdam EA, Wenger NK, Brindis RG, et al. 2014 AHA/ACC guideline for the management of patients with non-ST-elevation acute coronary syndromes: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2014;64:e139-e228.

9.    Fleisher LA, Fleischmann KE, Auerbach AD, et al. 2014 ACC/AHA guideline on perioperative cardiovascular evaluation and management of patients undergoing noncardiac surgery: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines. J Am Coll Cardiol. 2014;64:e77-e137.

10.    Parashar A, Agarwal S, Krishnaswamy A, et al. Percutaneous intervention for myocardial infarction after noncardiac surgery: patient characteristics and outcomes. J Am Coll Cardiol. 2016;68:329-338.

From the ¹Department of Medicine, Columbia University Division of Cardiology, Mount Sinai Medical Center, Miami Beach, Florida; and ²Department of Medicine, Division of Cardiology, New York University School of Medicine, New York, New York.

Disclosure: The authors have completed and returned the ICMJE Form for Disclosure of Potential Conflicts of Interest. The authors report no conflicts of interest regarding the content herein.

Manuscript accepted July 24, 2018.

Address for correspondence: Nathaniel Smilowitz, MD, Leon H. Charney Division of Cardiology, New York University School of Medicine, 530 First Avenue, HCC-14, New York, NY 10016. Email: Nathaniel.Smilowitz@nyumc.org