Prophylactic Coronary Angiography in Medium- to High-Risk Patients Undergoing Major Vascular Surgery - Prophylactic Coronary Angiography in Medium- to High-Risk Patients Undergoing Major Vascular Surgery

Description:

Two recent trials, CARP and DECREASE-V, noted that routine coronary artery revascularization before vascular surgery is not associated with improved outcomes. Accordingly, current American College of Cardiology/American Heart Association guidelines recommend noninvasive testing for patients undergoing vascular surgery, only if two or more risk factors, as assessed by Lee’s revised cardiac risk index (RCRI), are present.

Given that vascular surgery patients continue to have a high rate of perioperative cardiovascular complications, the current trial sought to evaluate the role of routine coronary angiography and revascularization if needed in patients undergoing major vascular surgery, with an RCRI ≥2.

Hypothesis:

Selective angiography in patients with a positive stress test prior to planned vascular surgery would be associated with better outcomes than routine angiography in all patients.

Study Design

Study Design:

Patients Screened: 672
Patients Enrolled: 208
NYHA Class: NYHA class III/IV: 44.4%
Mean Follow Up: 58 months
Mean Patient Age: 74 years
Female: 20

Patient Populations:

  • Elective major vascular surgery, aorto-iliac obstructive disease, AAA repair
  • RCRI ≥2

Primary Endpoints:

  • MACE (myocardial infarction, cerebrovascular accident, congestive heart failure, need for new revascularization) at 3 years

Secondary Endpoints:

  • MACE between screening and 30 days post-procedure

Drug/Procedures Used:

Patients were randomized to a "selective strategy," in which coronary angiography was done only in the setting of a positive stress test, or routine angiography ("systematic strategy") in which coronary angiography was performed in all patients, without stress testing. Peripheral angiography was performed in all patients as part of a routine diagnostic workup before major vascular surgery to confirm vascular preoperative noninvasive testing and/or to gain additional anatomical information (e.g., location of aneurysmal neck in abdominal aortic aneurysm [AAA] patients).

In all patients for whom coronary angiography was indicated, coronary and peripheral vascular angiography were performed at the same time and by the same team. A patient was considered eligible for a myocardial revascularization procedure if one or more major coronary vessels, suitable for revascularization, showed a significant stenosis. A staged approach (myocardial revascularization followed by vascular surgery) was typically performed. Combined procedures (i.e., repair of AAA immediately after myocardial revascularization procedure in the same surgical session) were reserved only for patients with large aortic aneurysms (≥6 cm) and/or signs of impending rupture.

Concomitant Medications:

All patients were administered statins, beta-blockers, and low molecular weight heparin 1 week before admission, discontinuing antiplatelet therapy. Patients undergoing percutaneous coronary intervention were discharged on a dual antiplatelet therapy, consisting of 75 mg/day clopidogrel or 250 mg/day ticlopidine, plus 100 mg/day aspirin, and were scheduled for vascular surgery within 30-60 days.

Principal Findings:

A total of 208 patients were randomized, 103 to the selective strategy arm, and 105 to a systematic strategy. Baseline characteristics were fairly similar between the two arms. About 38% had diabetes; prior myocardial infarction was noted in 32% of the patients, with prior coronary artery bypass grafting in 16.5%. Prior vascular surgery was noted in 13% of the patients; all patients were undergoing aortic surgery—either open AAA repair (39.5%), or bypass for aorto-iliac disease (60.5%). About 23.5% of the patients had Canadian Cardiovascular Society class III/IV angina, and 44.4% had New York Heart Association class III/IV shortness of breath.

The incidence of coronary artery disease (CAD) was high in the study population—44.7% in the selective strategy group, and 61.9% in the systematic strategy group (combined 53.4%), of which around 11% had left main disease, 21.4% had left anterior descending disease, and the vast majority (73%) had multivessel disease, including 41.7% (20.7% of the total study population) with three-vessel disease. Complete revascularization was achieved in 91.3% of patients with CAD in the selective strategy group, and 93.8% in the systematic strategy arms, respectively.

At 30 days, there was no difference in major adverse cardiac events (MACE) between the selective versus systematic strategy arms (4.8% vs. 2.8%, respectively; p = 0.7), or MACE and cardiovascular death (11.7% vs. 4.8%, p = 0.1), although length of stay was lower in the systematic strategy arm (7.5 vs. 6.8 days, p = 0.03). Over a mean follow-up of 58 months, long-term survival was significantly lower in the selective strategy arm, as compared with the systematic strategy arm (p = 0.01). The 4-year freedom from cardiac endpoints, including mortality, was significantly lower in the selective strategy arm as well (69.6% vs. 86.6%, p = 0.04).

Interpretation:

The results of this trial indicate that a strategy of routine angiography in patients undergoing medium- to high-risk vascular surgery (aortic) is associated with a reduction in MACE, including cardiac mortality, at 4 years, as compared with a selective angiography strategy, which is performed only in patients with a positive preoperative stress test.

These findings are very interesting, and add to a growing debate on preoperative risk stratification in patients undergoing vascular surgery. Two earlier trials, CARP and DECREASE-V, showed no benefit with routine revascularization in patients undergoing vascular surgery.

Several reasons may account for these contradictory findings. One reason may be the inclusion of patients with significant left main stenosis in this cohort, which were excluded from CARP. DECREASE-V aimed to include a cohort of patients with extensive CAD, and had a similar incidence of CAD, including left main disease, as compared with the current study. All patients in the current study were scheduled to undergo aortic surgery, either AAA repair or aorto-iliac bypass. Both CARP and DECREASE-V included patients undergoing distal bypasses as well, which can be considered as a lower risk procedure, as compared with aortic surgery.

Although this trial throws open the field of preoperative risk stratification prior to major vascular surgery, a few points to consider are:

1) Of 672 patients who were screened for this trial, only 31% had an RCRI ≥2. Thus, every patient going for vascular surgery may still not warrant preoperative angiography.

2) The trial included about 25% patients with symptomatic Canadian Cardiovascular Society class III/IV angina, and at least some of these patients had a high pretest likelihood of significant CAD, who would thus likely benefit from coronary angiography, irrespective of their need for vascular surgery. Further trials on this topic are warranted.

References:

Monaco M, Stassano P, Tomasso LD, 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;54:989-96.

Clinical Topics: Anticoagulation Management, Cardiac Surgery, Heart Failure and Cardiomyopathies, Invasive Cardiovascular Angiography and Intervention, Noninvasive Imaging, Vascular Medicine, Aortic Surgery, Cardiac Surgery and Heart Failure, Interventions and Coronary Artery Disease, Interventions and Imaging, Interventions and Vascular Medicine, Angiography, Nuclear Imaging

Keywords: Coronary Artery Disease, Myocardial Infarction, Follow-Up Studies, Heparin, Low-Molecular-Weight, Ticlopidine, Risk Factors, Constriction, Pathologic, Dyspnea, Percutaneous Coronary Intervention, Length of Stay, Coronary Angiography, Myocardial Revascularization, Coronary Artery Bypass, Aortic Aneurysm, Abdominal, Diabetes Mellitus, Exercise Test


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