Several small studies examined the question of whether or not to perform routine preoperative angiography in patients undergoing noncardiac vascular surgery.

For example, a study by Dr Ambrosio, Mario Monaco, MD, from Istituto Clinico Pineta Grande, in Castel Volturno, Italy, and colleagues evaluated the outcomes of 208 medium-risk to high-risk patients undergoing major vascular surgery who received preoperative angiography and, if needed, revascularization of obstructive lesions.5 Approximately one-half of patients were selected to undergo angiography based on positive stress test results (the “selective strategy” group) and the rest underwent angiography without any prior noninvasive testing (the “systematic strategy” group).


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Coronary revascularization was performed more often in the systematic strategy group (58.1%) than in the selective strategy group (40.1%; P =.01). While rates of in-hospital major adverse cardiovascular events were similar in both groups, overall and cardiovascular event-free survival were significantly higher in patients in the systematic strategy group over 7 years.5

Another study compared systematic angiography vs no angiography before carotid endarterectomy in 426 patients without evidence of CAD.4 Approximately one-third of patients in the angiography group underwent revascularization via percutaneous coronary intervention (PCI) prior to surgery. Postoperative mortality and stroke rates were similar in both groups. No myocardial events occurred in the angiography group, while 9 events, including 1 fatal MI, occurred in the no-angiography group (P =.01).4 Follow-up at 3.5 years revealed patients in the angiography group to be significantly less likely to have an MI than patients who did not undergo preoperative angiography (1.4% vs 15.7%; hazard ratio, 0.78; 95% CI, 0.024-0.256; P <.001).6

Dr Ambrosio suggested that requiring surgery for vascular disease may be an indication for performing routine angiography without prior noninvasive testing. “One may argue that since atherosclerosis is a systemic disease, it is quite likely that patients with carotid artery disease, or peripheral artery disease, or disease of the aorta — who also tend to have multiple cardiovascular risk factors — may also have coronary involvement,” Dr Ambrosio said. “Thus, one may reasonably decide to skip ‘intermediate’ noninvasive testing and opt for a direct angiography strategy, regardless of the inherent risks of surgery itself.”

Evidence Against Angiography Before Noncardiac Surgery

However, Dr McFalls argues that choosing to revascularize obstructive coronary lesions before noncardiac surgery does not improve outcomes. “The evidence does not support that decision,” he said.

Dr McFalls and colleagues examined the utility of coronary revascularization prior to noncardiac surgery in the Coronary Artery Revascularization Prophylaxis (CARP) trial.7 The study compared preoperative coronary revascularization vs no revascularization in 510 patients with at least 70% stenosis in 1 or more coronary arteries undergoing vascular surgery. Participants had undergone angiography based on clinical assessment for cardiac risk. Revascularization procedures included PCI and coronary artery bypass grafting (CABG). No differences were found between the groups in rates of postoperative MI within 30 days or in mortality rates at 2.7 years.7

A subgroup analysis of 462 patients from the CARP study plus 586 patients who had undergone screening but were not included in CARP revealed a survival benefit with revascularization in patients with left main coronary artery stenosis (P <.01). However, no survival benefit was demonstrated in patients with 2-vessel or 3-vessel disease undergoing preoperative revascularization.8

While revascularization improved survival in patients with left

main coronary artery stenosis, Dr McFalls noted that these patients represented only about 5% of the study population. “I don’t think that the evidence is there that we should treat a lot of people to look for a small subset that may benefit,” he said.

The CARP trial also showed that preoperative revascularization doubled the risk of delaying or cancelling surgery, Dr McFalls noted. “Fewer people will get the needed operation, and those who do get the operation have to wait at least 3 times longer,” he said. “It’s not budget neutral.”

However, Dr McFalls indicated that revascularization based on preoperative angiography findings should be considered in patients with urgent clinical problems, such as unstable angina. “Patients in these scenarios should be considered primarily because of the clinical uncertainty of the cardiovascular condition,” he said.

The Takeaway

According to Dr Ambrosio, there is “relatively little firm evidence” regarding the utility of preoperative angiography and revascularization before noncardiac surgery; the data are conflicting and suffer from limitations. The studies supporting angiography before noncardiac surgery have been criticized for lack of blinding and small size, while the CARP study mostly included patients with 1-vessel or 2-vessel disease, which may have diluted any observed benefit in higher-risk patients.2,7

Dr Ambrosio noted that the lack of large randomized trials may be due to several factors: heterogeneity in the types of noncardiac surgery, heterogeneity in patient risk profiles, and lack of clinical equipoise when selecting patients for participation in a trial that randomly assigns patients to angiography or no angiography regardless of risk factors.

“Many unanswered questions regarding the role of preoperative angiography remain,” he said.

Dr McFalls also acknowledged that opinions differ with regard to preoperative angiography. However, he advocates for angiography and revascularization primarily based on the clinical scenario. “I suggest adhering to the clinical compelling reasons to get somebody into the cath lab, not the need to define anatomical characteristics,” he said.

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References

  1. Devereaux PJ, Goldman L, Cook DJ, Gilbert K, Leslie K, Guyatt GH. Perioperative cardiac events in patients undergoing noncardiac surgery: a review of the magnitude of the problem, the pathophysiology of the events and methods to estimate and communicate risk. CMAJ. 2005;173(6):627-634. doi:10.1503/cmaj.050011
  2. Schulman-Marcus J, Pashun RA, Feldman DN, Swaminathan RV. Coronary angiography and revascularization prior to noncardiac surgery. Curr Treat Options Cardiovasc Med. 2016;18(1):3. doi:10.1007/s11936-015-0427-5
  3. 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. doi:10.1016/j.jacc.2014.07.944
  4. Illuminati G, Ricco JB, Greco C, et al. Systematic preoperative coronary angiography and stenting improves postoperative results of carotid endarterectomy in patients with asymptomatic coronary artery disease: a randomised controlled trial. Eur J Vasc Endovasc Surg. 2010;39(2):139-145. doi:10.1016/j.ejvs.2009.11.015
  5. Monaco M, Stassano P, Di Tommaso L, et al. Systematic strategy of prophylactic coronary angiography improves long-term outcome after major vascular surgery in medium- to high-risk patients: a prospective, randomized study. J Am Coll Cardiol. 2009;54(11):989-996. doi:10.1016/j.jacc.2009.05.041
  6. Illuminati G, Schneider F, Greco C, et al. Long-term results of a randomized controlled trial analyzing the role of systematic pre-operative coronary angiography before elective carotid endarterectomy in patients with asymptomatic coronary artery disease. Eur J Vasc Endovasc Surg. 2015;49(4):366-374. doi:10.1016/j.ejvs.2014.12.030
  7. McFalls EO, Ward HB, Moritz TE, et al. Coronary-artery revascularization before elective major vascular surgery. N Engl J Med. 2004;351(27):2795-2804. doi:10.1056/NEJMoa041905
  8. Garcia S, Moritz TE, Ward HB, et al. Usefulness of revascularization of patients with multivessel coronary artery disease before elective vascular surgery for abdominal aortic and peripheral occlusive disease. Am J Cardiol. 2008;102(7):809-813. doi:10.1016/j.amjcard.2008.05.022