Rise in Endovascular Therapy for PAD Parallels Improved Outcomes

Key Points:
Endovascular treatment for PAD has waxed as surgery has waned
Contemporary PAD patients tend to be sicker
Nonetheless, decreases seen in major amputations, mortality

From: TCTMD - The Source for Interventional Cardiovascular News and Education
By Kim Dalton
Wednesday, January 13, 2010


Over the past decade, as angioplasty increasingly displaced surgery for revascularization of peripheral arterial disease (PAD), rates of major amputation as well as mortality and other complications declined. The shift occurred despite patients presenting with more comorbidities, according to a study published online January 4, 2010, ahead of print in the Journal of Vascular Surgery.
To evaluate the shift in treatment of lower-extremity PAD and the impact of this trend on different patient groups, investigators led by Roman Nowygrod, MD, of Columbia University Medical Center (New York, NY), analyzed data from the National Inpatient Sample as well as New York State inpatient and outpatient databases on patients at least 40 years old who underwent either surgical or endovascular lower leg procedures or major amputations from 1998 to 2007.
Comparing 2007 with 1998, hospitalizations for invasive treatment of lower-extremity PAD decreased slightly, from 192 to 183 per 100,000 people aged ≥ 40 years. However, the proportion of open vs. endovascular revascularizations changed substantially, with the former declining 67% while the latter almost doubled. Meanwhile, the per capita volume of major amputations decreased by 38%.
Although most procedures were performed for critical limb ischemia, the overall rate of lower-extremity revascularizations in this group declined by 20%, from 93 per 100,000 in 1998 to 75 per 100,000 in 2007. Likewise, the incidence of interventions (endovascular or open surgical) for other PAD diagnoses decreased slightly, from 78 to 70 per 100,000. On the other hand, after a stable period from 1998 to 2002, interventions for claudication increased by almost 50% from 2003 to 2007.
The rate of procedures for critical limb ischemia declined steeply for octogenarians (from 317 to 240 per 100,000) and more moderately for patients aged 65 to 79 years (199 to 160 per 100,000), while interventions for claudication increased for all age groups (≥ 40 years). Meanwhile, outpatient interventions increased for all PAD diagnoses in all age groups.
Differing Fortunes of Open vs. Endovascular Intervention

While the proportion of open procedures decreased, use of endovascular revascularization increased substantially, quadrupling for critical limb ischemia and doubling for claudication.

Over the same period, rates of major amputations declined from 42% to 30% for critical limb ischemia, from 0.9% to 0.3% for claudication, and from 18% to 14% for other PAD diagnoses. Importantly, the improvement in patients with critical limb ischemia occurred despite the fact that they were twice as likely to have diabetes and 3 times more likely to have renal disease as those with claudication. In fact, comparable reductions in major amputations were seen in both diabetics (27%) and nondiabetics (32%).
Complications Decline for Both Revascularization Strategies
Over the study period, even as the prevalence of comorbidities such as CAD, COPD, renal disease, and (among claudicants) diabetes increased, operative mortality rates decreased for both revascularization procedures, as did postoperative cardiac complications, bleeding, and stroke. In addition, the incidence of infection declined with endovascular revascularization.

The mean length of hospital stay also declined over the decade, from 9.5 days in 1998 to 7.6 days in 2007. In addition, 35% of patients were discharged within 1 to 2 days in 2007, compared to only about 16% in 1998.
“Our analysis of national inpatient and outpatient state data supports the trend toward increasing treatment of PAD by endovascular intervention,” the authors write, predicting that given the safety of the minimally invasive approach, the percentage of outpatient procedures is likely to continue to grow.
The investigators caution that “although the decline in amputation rates seems likely due in large part to the increased use of endovascular interventions, other variables are clearly operative, including improved endovascular technology, better diabetes management and foot care, and improving and more ubiquitous application of medical therapies.”
In addition, the study findings are based on administrative data and thus subject to certain limitations, the authors note. For example, the absence of anatomic characteristics and condition variables precluded a careful analysis of treatment groups. Also, the inability to track patients over time meant they could not distinguish primary from secondary interventions, readmission, or complications.
Endovascular Trend Justified
“This is a very important paper,” William A. Gray, MD, of Columbia University Medical Center (New York, NY), told TCTMD in a telephone interview. “It both validates trends that we have perceived in the [vascular] community and justifies the increased use [of the endovascular approach] that it documents.”
“It’s not surprising that an easier, more accessible procedure is increasing,” Dr. Gray observed. “But that is nicely balanced by the fact that outcomes appear to be improving too—fewer mortalities, morbidities, shorter length of hospital stay. There are also fewer admissions for critical limb ischemia—likely because claudicants are being treated earlier. And treatment of claudicants may be leading to fewer patients with end-stage PAD.”
Though the study only reports hospitalization trends, “it speaks to the improvement in surveillance and care that these patients have been getting over the past decade, which is quite striking. This translates into a lot of saved limbs and lives,” Dr. Gray said, adding that it also reflects changes in the training of vascular surgeons, who are increasingly receiving instruction in endovascular techniques from fellow surgeons, as documented in a recent study in the Journal of Vascular Surgery.

Source:
Egorova NN, Guillerme S, Gelijns A, et al. An analysis of the outcomes of a decade of experience with lower extremity revascularization including limb salvage, lengths of stay, and safety. J Vasc Surg. 2010;Epub ahead of print.

Disclosures:
Drs. Nowygrod and Gray report no relevant conflicts of interest.