Amputation-Free Survival With Endovascular Therapy vs Bypass Surgery in Critical Limb Ischemia

Endovascular revascularization was shown to result in similar rates of amputation-free survival compared to surgical revascularization in patients with critical limb ischemia (CLI), according to a study published in JACC Cardiovascular Interventions.

As the best treatment strategy for these patients is still under debate, researchers at various cardiovascular clinics in Germany sought to compare both approaches to revascularization. They pointed out that there is only 1 published randomized controlled trial comparing endovascular therapy and bypass surgery.

In the CRITISCH trial (Registry of First-Line Treatments in Patients With Critical Limb Ischemia; ClinicalTrials.gov identifier: NCT01877252), 1200 patients from 27 tertiary vascular centers with CLI defined by rest pain or tissue loss lasting more than 2 weeks (Fontaine stages III-IV or Rutherford classes 4-6) and/or ankle-brachial index < 0.40 were prospectively enrolled. The selection of specific treatment was left to the discretion of each treating physician. The primary end point was amputation-free survival (ie, time to major amputation and/or death from any cause). Time until death, time until amputation at index limb, time until major amputation, and/or any reintervention at the index limb were designated as secondary end points.

A pre-specified interim analysis aimed at demonstrating noninferiority of endovascular therapy vs bypass surgery as to the hazard ratio (HR) of amputation-free survival (noninferiority bound = 1.33; interim α  = 0.0058).

More than half of the patients (53%) were treated with endovascular therapy while 24% were treated using bypass surgery. Both groups were followed up for a median of 1 year, and the rate of amputation-free survival was 75% in the endovascular group and 72% in the bypass group.

At 1 year, the event-free survival rate was 65% in the endovascular group and 62% in the bypass group; the total number of events for each group were 212 (33%) and 98 (35%), respectively.

The multivariate Cox regression model delivered an HR of amputation-free survival of 0.91 with an estimated 2-sided 95% CI of 0.70-1.19, after adjustment for several confounders. This model was also used to create the 1-sided CI of the HR. Noninferiority of endovascular therapy vs bypass surgery for amputation-free survival was confirmed (HR: 0.91; upper bound of 1-sided [1 – 0.0058]; CI, 1.29; P =.003).

The group treated with endovascular therapy had a median in-hospital stay length of 7 days while those treated with bypass surgery stayed a median of 15 days (P <.001) In-hospital mortality was 1% for those treated with endovascular therapy vs 3% for those treated with bypass surgery (P =.085); the major amputation rate was 3% in the endovascular group and 4% in the bypass group (P =.841).

The researchers noted that chronic kidney disease in particular contributed to in-hospital mortality. As such, they recommended further investigation in this patient cohort to determine the best treatment.

“This study highlights that when physicians are free to individualize therapy for their CLI patients, they achieved encouraging outcomes with both therapies,” the researchers concluded.

Study Limitations

• Selection criteria for each patient was not reported; these can only be extrapolated by comparing baseline characteristics between groups.
• Lack of specifics regarding endovascular products/manufacturers, previous interventions, primary or secondary patency of treated lesions or implanted bypass grafts, time to wound healing, and precise reason of death.
• A cost analysis was not conducted.

Reference

Bisdas T, Borowski M, Stavroulakis K, et al; for the CRITISCH collaborators. Endovascular therapy vs bypass surgery as first-line treatment strategies for critical limb ischemia. Results of the interim analysis of the CRITISCH Registry. JACC Cardiovasc Interv. 2016;9(24):2557-2565. doi:10.1016/j.jcin.2016.09.039.