Fewer Amputations, Hospital Deaths as Treatment Switches for Patients with Critical Limb Ischemia

The shift to a less invasive method of treating patients who suffer debilitating critical limb ischemia has been accompanied by a drop in major amputations and hospital deaths, according to a study published today in the Journal of the American College of Cardiology.

The study, by Cleveland Clinic authors Shikhar Agarwal, MD, MPH; Karan Sud, MD; and Medhi H. Shishehbor, DO, MPH, PhD; was released ahead of the 65th Scientific Session of the American College of Cardiology, which will take place April 2-4, 2016, in Chicago, where it will be presented.¹

Up to 10 million Americans suffer critical limb ischemia (CLI), an obstruction of the arteries that reduces blood flow to the hands, feet, and legs, causing severe pain and even sores in the worst cases. Historically, these blockages were treated surgically. Starting in the 1980s, methods of endovascular revascularization became more popular; however, as Joshua A. Beckham, MD, MS, found in a 2007 paper in Circulation, through the year 2000 rates of amputation actually increased, suggesting the catheter-based interventions were being used to improve quality of life rather than as a primary means of avoiding loss of limbs.²

Agarwal et al find that between 2003 and 2011 the amputations rates took a positive turn as endovascular revascularization continued to rise. The authors are careful to not ascribe the drop in amputations to the procedure itself, and suggest that overall cardiovascular care may be improving. They highlight stubborn disparities that remain, as the poor and members of minority groups continue to have higher amputation rates.

Still, the overall news is good, and the authors find the shift has been positive for managed care as well. “Despite similar rates of major amputation, endovascular revascularization was associated with reduced in-hospital mortality, mean length of stay and mean cost of hospitalization compared to surgical revascularization,” they write.

Results. The authors evaluated records from the Nationwide Inpatient Sample for patients with CLI from 2003 to 2011, capturing a total of 642,433 admissions, or roughly 150 of every 100,000 people in the United States. The share of patients having surgical revascularization dropped from 13.9% in 2003 to 8.8% in 2011. At the same time, the rate of endovascular revascularization rose from 5.1% to 11.0% over this same period. The data also included patients with sequential revascularization.

Along this shift came a drop in major amputations, even though the share of the population with CLI remained stable. The annual in-hospital mortality rate from CLI fell from 5.4% to 3.4% over the study period, while annual major amputations fell from 16.7% in 2003 to 10.8% in 2011. Also, length of stay fell from a mean of 10.0 days in 2003 to 8.4 days in 2011. While overall hospitalization costs for CLI did not decrease during the study period, mean length of stay was shorter for the endovascular group (8.7 days vs 10.7 days), and the average cost was less ($31,679 vs $32,485), despite similar major amputation rates.

The authors noted CLI patients were frequently admitted to the hospital for other reasons, including complications from diabetes, septicemia, and post-procedure complications. Over the study period, more patients were admitted on an emergent basis, and more had no insurance or were on Medicaid.

Disparities. As expected, older patients with CLI had higher in-hospital mortality and amputation rates and were more likely to have some type of revascularization procedure. Women were more likely to have endovascular procedures. The authors found that blacks and other nonwhites had “significantly higher rates of major amputation and lower rates of revascularization,” than whites. Higher socioeconomic status was associated with lower amputation rates. Urban teaching hospitals had higher rates of amputations than rural hospitals, but these may be due to a more complicated case mix. There were significant disparities by geography as well, with patients in the South most likely to have amputations, and those in the West most likely to have an in-hospital death.

In the past decade, the length of stay associated with CLI dropped significantly. Lower costs associated with endovascular procedures confirm those of other trials, but the authors caution, “Patient-specific variables along with outcomes over a 30-day follow-up period, especially readmission rates, would

Be necessary to understand implications of these observations in a definitive manner. Further exploration of these matters would be vital with the widespread implementation of the Affordable Care Act and as the penalties for 30-day readmissions are invoked universally.”

References

1. Agarwal S, Sud K, Shishehbor MH. Nationwide trends of hospital admission and outcomes among adults with critical limb ischemia from 2003 to 2011 [published online March 21, 2016]. J Am Coll Cardiol. 2016; http://dx.doi.org/10.1016/j.jacc.2016.02.040.

2. Beckham JA. Peripheral endovascular revascularization. Circulation. 2007;115:550-552.