Initial Thrombolysis Found to Be the Most Costly Strategy for Acute Limb Ischemia

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In a real-world setting, the downstream demands on healthcare resources entailed by first-line use of catheter-directed thrombolysis in nonembolic acute limb ischemia (ALI) make it a less cost-effective strategy than surgical or endovascular intervention. The findings, published online August 23, 2014, ahead of print in the Journal of Vascular Surgery, show that the largest contributor to overall cost is not treatment but the length of hospital stay, which is driven by the need for reintervention and readmission.

Methods
Fedor Lurie, MD, PhD, and colleagues from the University of Toledo (Toledo, OH), analyzed data on 205 patients with nonembolic ALI who underwent invasive treatment at 4 Ohio community hospitals between 2009 and 2012. The cohort was divided into 5 groups based on their initial treatment:
  • Catheter-directed thrombolysis (n = 68)
  • Catheter-directed thrombolysis plus angioplasty within 24 hours (n = 16)
  • Open surgery (n = 60)
  • Endovascular procedures (including atherectomy, balloon angioplasty, thrombectomy with AngioJet [Medrad; Warrrendale, PA], stenting, or a combination; n = 33)
  • Combination of open and endovascular techniques (n = 28)
 
Patients with probable or obvious embolism, which would be more likely to be treated with modalities other than thrombolysis, were excluded to ensure a more appropriate comparison among all initial treatments. Costs were calculated in 2012 US dollars.

 

The cause of ALI was an occluded native vessel in 115 patients (56.1%) and an occluded bypass graft in the remainder. Occlusion was located proximal to the popliteal artery in 81 patients and in or beyond the popliteal artery in 124 patients. At admission, most patients (88.8%) had class IIa ischemia.

Overall, multivariate analysis showed no association between initial treatment selection, patient characteristics, occlusion location, or ischemic class, individually or in combination. However, patients with bypass graft occlusions were more likely to initially receive catheter-directed thrombolysis (with or without angioplasty), while those with occlusion of a native vessel were more likely to be treated with open surgery, endovascular therapy, or a hybrid procedure (adjusted OR 3.9; 95% CI 2.2-7.0).

Reintervention in About One-Third

For two-thirds of patients (67.3%), initial treatment resulted in overall primary success with no further intervention required during hospitalization; 29.7% required a second intervention and 5.4% a third. In addition, 5 patients underwent amputation and 2 died. The proportion of reinterventions was highest in the thrombolysis group (62%). The time from initial treatment to reintervention was 2.1 ± 1.8 days. Complication rates did not differ among the treatment arms. Amputation-free survival at discharge was highest in the endovascular and hybrid groups (100%) and lowest in the thrombolysis/angioplasty group (87.5%).

Within 30 days of discharge, 24 patients were readmitted to the hospital for reasons related to their limb ischemia, with 2 undergoing amputation. Readmission was most frequent in the thrombolysis and thrombolysis/angioplasty groups; multivariate analysis confirmed a relationship between higher rates of readmission and initial treatment independent of other risk factors (OR 3.4; 95% CI 1.5-7.4).

 Major contributors to the total cost of hospitalization were:

  • Hospital length of stay (including ICU time): 43%
  • Procedures: 23%
  • Supplies (eg, catheters, stents) excluding medications: 13%

Hospital Stays at Root of Differences

Hospital and ICU stays accounted for 67% and 43% of the cost variability, respectively, with each additional day costing $2,825 and $4,414, respectively. Although the relative contribution of hospital stay excluding ICU was similar among groups, ICU stay and related costs were highest in the thrombolysis and thrombolysis/angioplasty groups and lowest in the endovascular group.

Initial treatment cost was lowest for open surgery. The relative contribution of treatment to total initial hospitalization cost was similar among the groups except for endovascular, for which it was higher (P < .0001 for trend).

The relative contribution of treatment-associated costs to overall costs was similar regardless of the number of reinterventions, due primarily to differences in length of stay. Inclusion of readmission costs did not change the relationship, with the thrombolysis and thrombolysis/angioplasty groups remaining the most expensive (table 1).

Table 1. Hospital Costs by Initial Treatment

 

Initial Hospitalizationa

Total Cost Including Readmissionb

Catheter-Directed Thrombolysis

$31,606 ± $28,750

$34,800 ± $31,299

Catheter-Directed Thrombolysis Plus Angioplasty

 

$26,499 ± $17,411

 

$35,576 ± $32,785

Open Surgery

$17,207 ± $9,432

$18,015 ± $10,677

Endovascular Procedures

$20,645 ± $27,459

$21,788 ± $27,389

Hybrid Procedures

$21,274 ± $11,975

$21,732 ± $12,102

a P for trend = .004.
bP for trend = .001.

Patients in whom target-vessel patency was achieved showed greater overall cost-effectiveness. Hospital and ICU stays were shorter than for other patients (6.2 vs 10.5 days and 2.3 vs 5.3, respectively; both P < .0001), and the total cost of hospitalization, including readmission, was lower ($20,212 vs $38,039; P < .0001).

Real-World Differences in Practice, Not Patients

The authors say the study cohort is representative of the general population of nonembolic ALI patients and similar to those who have been enrolled in randomized controlled trials in terms of demographics, prevalence of major comorbidities, lesion location, and distribution of native artery and graft occlusions. Thus, the investigators say, “the differences in outcomes are likely to reflect differences in practice patterns, physician choices, and hospital logistics rather than the differences in patient populations.”

Although clinical outcomes were similar among the treatment groups and comparable to published data, Dr. Lurie and colleagues note, from a cost perspective the key findings are that most reinterventions and all multiple reinterventions were performed in the thrombolysis group, and the highest readmission rates were in the thrombolysis and thrombolysis/angioplasty groups. And in addition to their direct costs, reinterventions—especially if delayed—prolonged hospitalizations, which were a decisive contributor to overall cost.

Long ICU stays, a key factor in the high cost of thrombolytic therapies, could potentially be reduced with use of a safer and more effective lytic agent, the authors suggest, adding that cost-saving might also be achieved by decreasing the volume or cost of tPA.

Similarly, lowering the use or cost of supplies would reduce costs for endovascular strategies, they say. However, they see little opportunity for cutting hospital costs of open surgery, for which the procedure itself is the big-ticket item.  

 


Source:
Lurie F, Vaidya V, Comerota AJ. Clinical outcomes and cost-effectiveness of initial treatment strategies for nonembolic acute limb ischemia in real-life clinical settings. J Vasc Surg. 2014;Epub ahead of print.

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Initial Thrombolysis Found to Be the Most Costly Strategy for Acute Limb Ischemia

Disclosures
  • Drs. Lurie and Ramee report no relevant conflicts of interest.

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