At the Society for Vascular Surgery (SVS) annual meeting, held in Chicago in June, Joseph H Rapp and colleagues from the San Francisco DVA Medical Centre presented on the Coronary Artery Revascularisation Prophylaxis (CARP) Trial in his presentation titled ‘Outcomes for Patients Undergoing Revascularisation for Threatened Limb Loss and Claudication’.
The study’s objective was to investigate post-vascular surgical outcomes of patients with threatened limb loss (TLL) compared to those with claudication (CL) within a larger cohort selected for advanced coronary artery disease (CAD).
Rapp said the results from the study showed that patients with advanced CAD and either TLL or CL can undergo major vascular operations with low mortality and morbidity. These results were not improved by a strategy of preoperative coronary artery revascularisation. Furthermore, when selected for the presence of CAD, there was no difference in either perioperative or long term survival between patients with TLL and CL. Finally, the better than predicted outcomes for these high-risk patients may be due to aggressive preoperative care and intense medical management with beta blockers, statins, ACE inhibitors and ASA.
“We believe that the excellent outcomes achieved in this trial were due to the majority of patients being treated with beta-blockers which reduced demand ischemia,” Rapp told Vascular News following his presentation.
“Furthermore, coronary revascularisation may not have been beneficial in some patients because there were areas of the heart that could not be revascularised either because the appropriate coronary artery was occluded, too small or too diseased to be treated. This may be more common among patients with diffuse atherosclerosis, ie, both coronary and peripheral lesions.”
The prospective, randomised, CARP trial was held over 18 centres sponsored by the Cooperative Studies Program of the Department of Veterans Affairs.
Of the 510 preoperative vascular patients enrolled in the CARP Trial and randomised to coronary revascularisation or no revascularisation prior to PVD surgery, the indication for revascularisation was TLL in 152 and CL in 189 patients. The extent of CAD was determined by cardiac catheterisation. Eligible patients had to have at least one treatable coronary lesion of 70% or greater. Significant left main disease, EF <20% and aortic stenosis were excluded. After randomisation to CAD revascularisation or no revascularisation, patients were followed for mortality and morbidity perioperatively and followed for 2.7 years. Medical treatment of CAD was pursued aggressively. Results from the study found that patients with CL had a longer time from randomisation to vascular surgery, more abdominal operations and longer hospital stays. There were more urgent operations, re-operations, and limb loss among patients with TLL. The CL group had more perioperative MI’s although perioperative mortality was similar (TLL 3.5%, CL 1.8%, p=NS). In follow up the CL group also had numerically more MI’s (TLL 24, CL 41, p=0.057) but mortality was not different (TLL 26.3%, CL 21.6%, p=NS). Randomisation to CAD revascularisation prior to vascular surgery did not lower perioperative or long-term survival in either group. Rapp concluded by stating that in a patient cohort with severe CAD, perioperative and long-term mortality is similar between those with claudication and those with threatened limb loss. In spite of the multiple co-morbidities in the TLL patients, cardiac disease appeared to be the dominant factor in determining mortality, he said. Threatened limb loss and claudication patients with severe CAD can undergo vascular reconstruction with low mortality and morbidity and perioperative outcomes are not affected by cardiac revascularisation in either patients with threatened limb loss or claudication. He said the excellent mortality and morbidity outcomes could be due to the high number of study participants on beta-blockers and other cardioprotective drugs. However, Rapp did say “complete revascularisation of the heart is a bit of a myth” because there will often be small diseased vessels that cannot be bypassed.