More Aggressive Treatment of Ruptured AAA in United States Reduces In-Hospital Mortality vs England

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Patients with ruptured abdominal aortic aneurysms (AAAs) have substantially lower in-hospital mortality in the United States compared with England, according to an observational study published in the March 15, 2014, issue of The Lancet. The difference stems from the fact that US patients are far more likely to receive intervention, especially endovascular aneurysm repair (EVAR), researchers say.

Peter J. Holt, PhD, of St. George’s, University of London (London, United Kingdom), and colleagues extracted data on patients admitted to the hospital with ruptured AAAs between 2005 and 2010 from England’s Hospital Episode Statistics (n = 11,799) and the United States’ Nationwide Inpatient Sample (n = 23,838).

US patients were more likely to undergo intervention, specifically EVAR, than their English counterparts. They had lower in-hospital mortality, though as a whole, post-intervention mortality rates were similar. Patients treated in the United States also were more likely to be discharged to another healthcare provider (vs their usual place of residence). Despite the fact that both countries have a similar prevalence of teaching hospitals, patients with ruptured AAAs were almost twice as likely to be treated at such a facility in the United States vs England (table 1).

Table 1. Outcomes After Ruptured AAA by Country

 

England
(n = 11,799)

United States
(n = 23,838)

P Value

Prevalence of Intervention
Overall
EVAR

 
58.45%
8.54%

 
80.43%
20.88%

 
< 0.0001
< 0.0001

In-Hospital Mortality

65.90%

53.05%

< 0.0001

Post-Intervention Mortality
Overall
EVAR
Open Repair

 
41.77%
31.58%
42.72%

 
41.65%
26.84%
45.57%

 
0.88
0.0176
0.0001

Discharge to Home

79.99%

33.70%

< 0.0001

Treatment at Teaching Hospital

29.29%

51.53%

< 0.0001


Teaching hospitals and facilities with the highest bed capacities had lower rates of mortality and non-corrective treatment in both countries. Teaching hospitals also used EVAR more often.

After multivariable adjustment for age, sex, comorbidity, year, and hospital size or caseload, there were overlapping predictors of mortality in both countries (table 2).

Table 2. Independent Predictors of Mortality

 

OR (95% CI)

P Value

Admission on a weekend vs weekday
England
United States

 
1.144 (1.038-1.263)
1.156 (1.005-1.337)

 
0.0072
0.0432

Treatment outside a teaching institution
England
United States

 
1.462 (1.310-1.631)
1.272 (1.037-1.560)

 
< 0.0001
0.0238

Interhospital transfer vs treatment at presenting hospital
England

 
 0.646 (0.563-0.739)

 
 < 0.0001


Adjusted odds of non-corrective treatment were higher in England for patients admitted on a weekend or treated at a non-teaching institution, and they were lower in both countries for non-transferred patients.

Findings Can Guide Quality Improvement

“The large mortality difference is concerning,” Dr. Holt said in a press release. “Our data suggest that failure to deliver proven lifesaving surgery is a key reason why in-hospital survival for patients with [ruptured] AAA is lower in England. In particular, increased use of [EVAR] could save more lives and help to close the mortality gap.”

Additionally, the various predictors of mortality “might all be regarded as interrelated surrogate markers for the immediacy with which each patient with [ruptured] AAA had access to the full range of technology and care by a specialist multidisciplinary team,” the researchers say. “The results from our study [also] suggest that service configuration should focus on ensuring that patients with [ruptured] AAA are treated in a teaching hospital with a high aortic workload, offering both conventional and endovascular repair.”

The missing data on 30-day mortality and the proportion of patients who died after discharge from the primary facility are limitations of the study, the paper notes. Additionally, endovascular outcomes could not be adjusted for aortic morphology or hemodynamic status.

In an accompanying editorial, Martin Björck, MD, PhD, and Kevin Mani, MD, both of Uppsala University (Uppsala, Sweden), comment, “This international benchmarking of results of [ruptured] AAA repair serves as an excellent basis for improving quality of care of these patients.”

However, the absence of long-term outcomes is problematic, they write, noting, “With modern intensive care, many patients with [ruptured] AAA do survive the early postoperative period, but fail to recover fully.”

Though discussions on how to optimize treatment of ruptured AAA are important, as are national and international audits such as this study, Drs. Björck and Mani say, “As for most diseases, prevention is the key to success.

“Prevention will prolong the lives of many more patients with AAA in the future than efforts to improve treatment of ruptured AAA,” they conclude. “In the meantime, however, while awaiting the full effect of the AAA screening programs, work is to be done to improve survival of patients who have [ruptured] AAA.”

Study Details

In England, mean patient age was 78.2 years and 73.7% were men, while in the United States the figures were 76.6 years and 71.4%, respectively.

 


Sources:
1. Karthikesalingam A, Holt PJ, Vidal-Diez A, et al. Mortality from ruptured abdominal aortic aneurysms: clinical lessons from a comparison of outcomes in England and the USA. Lancet. 2014;383:963-969.

2. Björck M, Mani K. Improving outcomes for ruptured abdominal aortic aneurysm. Lancet. 2014;383.933-934.


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Disclosures
  • Drs. Holt, Björck, and Mani report no relevant conflicts of interest.

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