Study Explores Predictors of Nonhealing in CLI Patients After Endovascular Therapy

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After successful endovascular therapy in patients with critical limb ischemia (CLI), the only factors to independently predict nonhealing are insulin use, need for hemodialysis, and major tissue loss. The observational findings were published online August 22, 2014, ahead of print in Catheterization and Cardiovascular Interventions

While none of those risk factors comes as a surprise, Michael R. Jaff, DO, of Massachusetts General Hospital (Boston, MA) told TCTMD in an email, the study does carry another message for clinical practice—that “considering earlier intervention for CLI with minor loss before it becomes major tissue loss” may be worthwhile.

Methods
Norihiro Kobayashi, MD, of Saiseikai Yokohama City Eastern Hospital (Yokohama, Japan), and colleagues retrospectively assessed 182 CLI patients (n = 220 limbs) with tissue loss who were treated at their center between April 2007 and October 2012. Average follow-up was 23 ± 18 months.

Treatment was successful—defined as visible blood flow achieved via revascularization—for 164 out of 243 individual wounds (67.5%) in 130 patients (n = 149 limbs). Complete wound healing was seen in 40.2% of successfully treated wounds at 3 months, 57.3% at 6 months, 62.2% at 9 months, and 70.7% at 12 months. 

Many Differences but Few Independent Predictors

Age, sex, and non-ambulatory status were similar between patients whose wounds healed and those whose did not. Patients in the healing group had higher mean BMI and serum albumin level as well as lower prevalence of hemodialysis, less prior CAD, and lower mean C-reactive protein. They also were more likely to have received cilostazol.

Characteristics of wounds that healed also differed from those that did not. Toe wounds were more likely to heal than those located in other regions of the foot, while dorsal wounds were less likely to heal. Infected wounds and those with gangrene also were less apt to heal over follow-up. No differences were seen related to target lesion site. 

On multivariate Cox proportional hazards analysis, there were 3 factors that independently predicted nonhealing (table 1).

Table 1. Independent Predictors of Healing vs Nonhealing

 

Adjusted HR

95% CI

P Value

Insulin Use

0.541

0.329-0.890

.016

Hemodialysis

0.429

0.272-0.678

< .001

Major Tissue Loss

0.460

0.294-0.720

.001

 

Likelihood of nonhealing and the rate of repeat target limb revascularization increased progressively alongside the number of risk factors possessed by each patient. Limb salvage rates at 3 years were lower in patients with at least 2 predictors (78.3%) compared with those with 1 predictor (97.0%; log-rank P = .001) or none of the predictors (94.4%; log-rank P = .036). 

During the course of follow-up, minor amputation was required for 25.6% of wounds and major amputation for 9.4%; 37.7% of patients died. 

Risk of Nonhealing May Tip Balance Toward Surgery

Even when visible blood flow is reestablished to the wound, the aforementioned factors predict nonhealing, the researchers stress.

Endovascular therapy can match the wound healing levels produced by bypass surgery in patients with none or 1 of the predictors, they explain. “For high-risk patients with CLI, however, the wound healing and freedom from repeat target limb revascularization rates were low. Surgery may be appropriate if these high-risk patients with CLI have adequate inflow and outflow vessels as well as an adequate venous conduit, and acceptable surgical risk.”

Suitable candidates for surgery are rare among CLI patients, Dr. Kobayashi and colleagues acknowledge, thus “leaving [endovascular therapy] as the modality of choice for most of the ‘real-world’ subset of complex CLI patients.”

According to Dr. Jaff, the decision of whether to pursue endovascular therapy in patients at high-risk of nonhealing is “actually a societal question. Can we afford to perform multiple revascularizations on a patient with frank gangrene of the great toe, who is using insulin and is on hemodialysis?” 

Prevention can encourage better healing, he said. Not only do patients need to wear appropriately fitting shoes, they also should be seeing a podiatrist regularly for foot and nail care as well as regular inspection of the feet and toes for early skin lesions.

 


Source: 
Kobayashi N, Hirano K, Nakano M, et al. Predictors of nonhealing in patients with critical limb ischemia and tissue loss following successful endovascular therapy. Catheter Cardiovasc Interv. 2014;Epub ahead of print.

 

Disclosures:

 

  • Dr. Kobayashi reports no relevant conflicts of interest.
  • Dr. Jaff reports serving as a noncompensated advisor to Abbott Vascular, Boston Scientific, Cordis, Covidien, and Medtronic Vascular as well as a compensated advisor to Cardinal Health and board member of VIVA Physicians, a 501(c)3 not-for-profit education and research organization.

 

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