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Background

• Patients with peripheral vascular disease (PVD) have a high prevalence of concomitant coronary artery disease (CAD), which leads to a high incidence of perioperative cardiac complications during vascular surgery.
• This is the first randomized trial to study the effect of coronary artery revascularization before elective vascular surgery
• Previous investigations into the topic have yielded mixed results
  • The cohort study, The Coronary Artery Surgery Study with peripheral vascular disease. followed patients for 3.5 years and showed improved outcomes in the group receiving revascularization as compared to the group receiving conservative therapy.
  • On the other hand, studies using large registries of patients have shown no benefit and potential harm patients by causing complications and delays of the needed vascular surgeries.
• The study was funded by the Cooperative Studies Program of the Department of Veteran Affairs Office of Research and Development.

Methods

• Inclusion criteria- patients scheduled for an elective vascular operation for either an expanded abdominal aortic aneurysm or severe symptoms associated with PVD in the legs.
• Exclusion criteria
  • Need for urgent or emergency surgery
  • Severe coexisting illness
  • Prior revascularization without evidence of recurrent ischemia
  • Left main stenosis 50 percent or greater
  • Left ventricle ejection fraction less than 20 percent
  • Severe aortic stenosis
• Coronary angiography was recommended if the consulting cardiologist deemed the patient at increased risk of perioperative cardiac complications.
  • Risk was determined by a combination of factors including the presence or absence of ischemia in noninvasive stress testing as well as independent risk factors of CAD, such as prior stroke, insulin-dependent diabetes, and renal failure.
• Based on the angiogram, patients received revascularization if the patients had a stenosis of at least 70 percent and could tolerate a revascularization procedure
  • The decision to undergo percutaneos coronary intervention (PCI) versus coronary artery bypass (CABG) was left up to the local investigators
• After randomization, either the cardiac or vascular procedure was expected to be performed within three weeks
  • Patients undergoing a CABG waited three months beore recieving their vascular procedure
  • Patients undergoing PCI waited two weeks for their vascular procedure to be completed due to increase risk of instent thrombosis
• Three days after vascular surgery was performed cardiac enzymes were monitored and ekgs were obtained.  Three months after vascular surgery, LVEF was determined using radionuclide angiography.
• Primary end point: long term mortality
• Secondary end point: myocardial infarction, stroke, limb loss, and dialysis.
• Patients were followed for approximately five years and the study was powered to detect difference in the 3.5 year survival rate of at least 75 percent of the two arms of the study.
• This was an intention to treat analysis

Results

• 5859 patients were initally screened and of these, 510 patients were eventually enrolled
  • Of the 510 patients who underwent randomization, 258 were assigned to a strategy of preoperative coronary artery revascularization and 252 underwent no preoperative revascularization.
• No significant differences in the baseline characteristics.
• Of the 258 in the coronary artery revascularization arm, 240 (93 percent) actually underwent revascularization
  • 41 percent underwent CABG
  • 59 percent underwent PCI
  • Patients undergoing had a higher number of vessels revascularized (3 vs 1.3), higher death rates (2 vs 1.4), and longer stays in the hospital (7 vs 1 day)
  • 87 percent of the patients eventually underwent vascular surgery
    • Vascular surgery occured  a median 48 days after CABG and median 41 days after PCI
• Before vascular surgery, there were more deaths in the coronary-artery revascularization group  than the conservatively managed patients ( 10 deaths vs 1 death)
• There was no mention in the stude regarding the number of perioperative myocardial infarctions during vascular surgery.
• Primary endpt –> at a median of 2.7 years after randomization, mortality was 22 percent in the revascularization grp and 23 percent in the no revascularization grp (relative risk, 0.98; 95 percent CI, 0.70 to 1.37)
• At thirty days, there was not a significant difference in death rates in the two groups (3.1 vs 3.4 percent, p=0.87)
• Secondary endpt –> there was also not a significant difference between the coronary artery revascularization arm versus the conservative management arm in terms of the 
  • the rate of myocardial infarction, either using cardiac enzymes (11.6 vs 14.3 p=0.37) or cardiac enzymes with ECG (8.4 vs 8.4, p=0.99)
  • the rate of stroke (0.4 vs 0.8, p=0.59)
  • the percentage of patients losing of a leg (0.4 vs 0.8, p=0.11)
  • the percentage of patients requirine renal dialysis (0.4 vs 0.4, p=0.97)

Discussion

• The authors of this study conclude that, “Among patients with stable coronary artery disease, coronary artery revascularization before elective major vascular surgery does not improve long term survival”.
• There was no reduction in death, myocardial infarction, or length of stay after vascular surgery in either group.
• This is in line with the current recommendations of the American College of Cardiology, American Heart Association, and American College of Physicians, which only recommend coronary artery revascularization of patients with unstable cardiac symptoms or advances coronary disease that have been proven to have benefit irrespective of future surgery.

THE BOTTOM LINE:  In patients with stable coronary artery disease, preoperative coronary-artery revascularization before non-emergent vascular surgery does not improve the rate of death, decrease the number of postoperative myocardial infarctions or stroke,  decrease the percentage of patients losing a leg, or decrease the need for renal dialysis.