The CARP Trial
The Coronary Artery Revascularization Prophylaxis (CARP) trial was a landmark randomized controlled trial that definitively demonstrated prophylactic coronary revascularization before elective vascular surgery does not improve perioperative or long-term outcomes in patients with stable coronary artery disease. 1
Study Design and Population
The CARP trial screened 5,859 patients at 18 US Veterans Affairs hospitals who were scheduled for major vascular surgery (either abdominal aortic aneurysm repair or lower extremity revascularization). 1 Of these screened patients, 510 were ultimately randomized to either:
- Coronary revascularization group (n=258): Underwent either CABG (41%) or PCI with bare-metal stents (59%) before vascular surgery 1
- No revascularization group (n=252): Proceeded directly to vascular surgery with optimal medical therapy 1
Key inclusion criteria: Patients had to have ≥70% stenosis in one or more coronary arteries suitable for revascularization, identified on coronary angiography. 1, 2
Key exclusion criteria: Patients requiring urgent/emergent surgery, those with unstable coronary syndromes, ≥50% left main stenosis, LVEF <20%, or severe aortic stenosis were excluded from randomization. 1
Primary Findings
Short-Term Outcomes (30 days post-vascular surgery)
The trial found no difference in perioperative mortality or myocardial infarction rates:
- Death: 3.1% (revascularization) vs. 3.4% (no revascularization), P=0.87 1
- Postoperative MI: 12% (revascularization) vs. 14% (no revascularization), P=0.37 1
Long-Term Outcomes (2.7 years follow-up)
Mortality at 2.7 years was virtually identical between groups:
- 22% in revascularization group vs. 23% in no-revascularization group (RR 0.98,95% CI 0.70-1.37, P=0.92) 1
Clinical Implications
This trial fundamentally changed perioperative cardiac management by establishing that routine prophylactic revascularization is not indicated in stable patients. 1 The results led to the following guideline recommendations:
- Prophylactic myocardial revascularization before low- and intermediate-risk surgery in patients with proven ischemic heart disease is NOT recommended (Class III recommendation) 1
- Revascularization should only be performed according to standard indications for stable coronary artery disease, independent of the planned noncardiac surgery 1
Important Caveats
Left main disease exception: A retrospective analysis of patients with unprotected left main CAD (who comprised 4.6% of those assessed by angiography but were excluded from randomization) suggested improved survival with revascularization, though this was not part of the randomized comparison. 1
Timing considerations: In the revascularization group, vascular surgery occurred a median of 48 days after CABG and 41 days after PCI. 1 Notably, 10 of 33 patients who underwent coronary revascularization died before proceeding to vascular surgery, highlighting the procedural risks of prophylactic revascularization itself. 1
Patient selection: The trial enrolled predominantly stable patients—74% had three or more Eagle clinical risk criteria or moderate-to-large reversible defects on stress imaging, but all were clinically stable enough to undergo elective surgery. 1