Endovascular Therapy Promising for Critical Limb Ischemia

In patients with critical limb ischemia (CLI), endovascular therapy results in a high rate of limb salvage and improvement in quality of life (QOL), according to results from a prospective Japanese registry. However, about one-third of patients require reintervention within 1 year.

The results, published online January 29, 2013, ahead of print in Circulation: Cardiovascular Interventions, were first presented in November 2012 at the American Heart Association Scientific Sessions in Los Angeles, CA.

Researchers led by Masato Nakamura, MD, PhD, of Toho University Ohashi Medical Center (Tokyo, Japan), studied 312 patients with CLI who underwent endovascular therapy at 19 centers in Japan from December 2009 to July 2011 and were enrolled in the OLIVE registry.

High Limb Salvage Success

Following revascularization of culprit lesions, straight-line flow to the foot was obtained in 93%. Complications occurred in 4% of patients, including 5 vascular perforations, 4 hemorrhages at the puncture site, 2 vascular dissections, and 1 vascular rupture.

At 12 months, amputation-free survival, the primary endpoint, was seen in 74% of patients. On multivariate analysis, body mass index (BMI) < 18.5, heart failure, and wound infection were associated with a poor prognosis with amputation-free survival decreasing from 85% with no risk factors, to 48% with 2 or 3 such factors (P < 0.001). The major adverse limb event-free rate was 88%, with hemodialysis, heart failure, and Rutherford class 6 predicting a worse prognosis for such events (table 1).

Table 1. Factors Associated with Poor Prognosis at 1 Year

 

Additionally, the estimated major adverse cardiovascular event and major adverse event rates at 1 year were 17% and 27%, respectively.

The rate of healing for ischemic ulcers after revascularization was 25% at 42 days, 50% at 98 days, and 75% at 195 days. The median time required for complete healing was 97 days. Overall, 34% of patients underwent a repeat intervention to achieve freedom from ischemic symptoms.

Quality of life, as measured by standardized EuroQOL scores, improved over time, increasing from 0.63 ± 0.10 at baseline to 0.76 ± 0.12 at 1 year (P < 0.001).

Endovascular therapy consisted of either provisional nitinol stenting or balloon angioplasty alone, at the discretion of the operator.

Results Seen as Encouraging

According to the authors, the outcomes were “unexpectedly favorable” considering that just over half of patients had end-stage renal disease (ESRD) requiring dialysis.

“A number of conditions often connected to [ESRD], such as anemia, malnutrition, depressed immunity, and insufficient collagen in granulation tissue, also were independent predictors of limb salvage and mortality in the present study,” they add. Although the majority of patients also had diabetes, the disease was not an independent factor associated with wound healing and limb salvage, they note.

“The downside to this is that it is not a huge, multicenter study with randomization [to bypass surgery], but it does provide additional information that is needed about endovascular therapy,” said Michael R. Jaff, DO, of Massachusetts General Hospital (Boston, MA), in a telephone interview with TCTMD. “Our literature [on treating patients with CLI] is relatively thin,” he added. “The most important thing that this study demonstrates is that catheter-based treatment for CLI really does what it’s supposed to do, which is to prevent limb loss. This shows impressive limb salvage at follow-up.”

Dearth of Comparison Data Frustrating

The only prospective, randomized trial to compare endovascular therapy with surgical bypass was the European BASIL (BypAss verSus Angioplasty in severe Ischemia of the Leg) trial, which suggested that there is probably room for both therapies, Dr. Jaff said. For example, patients in good general health with a usable piece of saphenous vein and a life expectancy of at least 2 years tend to do well with bypass, while those with serious major comorbidities who do not have good saphenous veins or are not likely to survive 2 years do better with endovascular therapy, he explained.

However, in addition to lacking comparison data, there is a dearth of information on long-term follow-up of CLI patients who undergo endovascular therapy, Dr. Jaff continued.

“These approaches are relatively new, largely because the technologies have just started to permeate medical practice. The longest published follow-up we have is from the endovascular arm of the BASIL trial,” he said. “But the only endovascular strategy that was used was angioplasty. Now that we have atherectomy, drug-coated balloons and the emergence of potentially bioabsorbable devices, endovascular strategies for CLI are becoming more advanced and we need follow-up data on those as well.”

In terms of US data, the recently published XCELL (Xpert nitinol stenting for Critically ischEmic Lower Limbs) trial (Rocha-Singh K, Catheter Cardiovasc Interv. 2012;Epub ahead of print) showed a high rate of amputation-free survival (78%) at 1 year with infrapopliteal nitinol stenting, but also a high rate of restenosis.

Because of the need for repeat interventions with endovascular therapy, Dr. Jaff said it will become important moving forward to look at cost effectiveness and QOL.

“The real question is going to be ‘where does the value start to fade?’ depending on how often you have to reintervene,” he concluded.

Study Details

Patients’age was 73 ± 10 years. The most prevalent comorbid conditions were diabetes (71%), ESRD (52%), and coronary artery disease (46%). Approximately half (48%) of the cohort presented with history of intermittent claudication, and tissue loss was observed in 88%.

 

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Source:
Iida O, Nakamura M, Yamauchi Y, et al. Endovascular treatment for infrainguinal vessels in patients with critical limb ischemia: OLIVE registry, a prospective, multicenter study in Japan with 12-month follow-up. Circ Cardiovasc Interv. 2013;Epub ahead of print.

 

 

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