ST. LOUIS – A patient with a nontraumatic vascular emergency is significantly less likely to die today than a decade ago, with few exceptions, according to a new national analysis looking at 10 years of data. Unsurprisingly, endovascular surgery rates climbed over the study period, as did rates of acute limb ischemia, said Todd Vogel, MD, who discussed the study at the annual meeting of the Midwestern Vascular Surgical Society.
With an objective of evaluating trends for management of nontraumatic vascular emergencies in the United States, Dr. Vogel, who is chief of vascular and endovascular surgery at the University of Missouri–Columbia, and his colleagues examined frequencies of vascular emergencies, mortality rates, and how open versus endoscopic procedure technique affected the data.
To do this, the investigators used the U.S. National Inpatient Sample from 2005 to 2014 to identify nontraumatic vascular emergencies.
Using ICD-9 clinical management diagnosis and procedure codes allowed the investigators to capture a wide array of vascular emergencies, Dr. Vogel said. These included ruptured abdominal, thoracic, and thoracoabdominal aortic aneurysms (rAAAs, rTAAs, and rTAAAs, respectively), as well as acute limb ischemia, acute mesenteric ischemia, and ruptured visceral artery aneurysms.
Among the outcomes analyzed in the study were a trend analysis looking at how outcomes changed over time and an analysis of in-hospital mortality. Dr. Vogel and his colleagues also examined hospital resource utilization including length of stay and total hospital cost, inflation adjusted to 2014 costs.
The prevalence of endovascular intervention increased sharply over the study period, as one would expect, Dr. Vogel said. “At the beginning, we had about 24% of patients getting endovascular intervention for vascular emergencies, and currently, it’s 36%.” (P for trend, less than .0001).
Mortality dropped steeply overall, with overall mortality going from 13.80% to 9.14% during the study period (P less than .0001). Much of this decrease could be attributed to mortality for open procedures decreasing by over a third, from 16.5% to 10.7%, over the study period (P less than .0001). Endovascular procedure–related mortality decreased from 8.3% to 7.9% (P = .03).
Ruptured abdominal and thoracic aortic aneurysms were much less likely to be fatal in 2014 than in 2005. The overall mortality rate for rAAA went from 41.4% to 27.6% (P less than .0001) and rates for rTAAs dropped overall from 41.2% to 23.0% (P = .002).
However, endovascular rTAA repair mortality jumped from 14.9% to 27.4% (P = .0003) while mortality for open procedures plummeted from 51.3% to 16.7% (P less than .0001).
In-hospital mortality for some conditions didn’t change much over time: rTAAA mortality, for example, increased, but by a nonsignificant amount (44.7% vs. 47.6%; P = .06). “Mortality rates for rTAAA have remained static, despite the advances in treatment,” Dr. Vogel said.
Discussing these “concerning” results, Dr. Vogel noted that the increase in mortality “suggests an increased use of endovascular repair on higher-risk patients.” The mortality rate for ruptured visceral artery aneurysms did not change significantly either (16.7% vs. 6.7%, P = .09).
Overall, patients were 44% female and 66% white. “Over half of the patients were aged 70 or greater,” he said.
Acute limb ischemia was by far the most common vascular emergency, accounting for 82.4% of the total. Next most common were rAAAs, which made up just 10.79% of the vascular emergencies studied.
Looking at hospitalization trends over time, acute limb ischemia showed a slight trend up over the study period, from an occurrence rate of about 8.2 per 100,000 individuals at the beginning to about 9.0 per 100,000 by 2014.
Acute mesenteric ischemia also trended up, from an occurrence rate of about 4 per 1 million individuals in 2005 to about 6 per 1 million in 2014; rAAAs trended down, from about 13 per 1 million to a little over 9 per 1 million over the study period.
Among the other vascular emergencies incurring hospitalization, rTAAAs and ruptured visceral artery aneurysms were both rare, occurring in fewer than 7 per 10 million individuals, but both showed a slight upward trend over the study period. Slightly more common were rTAAs, which occurred at a rate of about 12 per 10 million individuals at the beginning of the study period and at slightly less than 15 per 10 million by the end.
Looking at hospital resource utilization, length of stay dropped significantly (P less than .004), but costs, unsurprisingly, increased over the study period, from about $25,000 to about $30,000 per occurrence (P less than .0001).
“The overall frequency of vascular emergencies has significantly increased over time,” Dr. Vogel said, “but in subgroup analysis ruptured abdominal [aortic] aneurysms are decreasing.” As endovascular procedures have increased, “The overall mortality has decreased, so we actually are doing better.” Some of this drop “may be due to improved perioperative care” as well as the increase in endovascular utilization, he noted.
In sum, though mortality has generally improved as endovascular procedures have become more common in vascular emergencies, “increased implementation of endovascular repair may not always improve outcomes,” Dr. Vogel said, especially in the context of an increasingly complex and aging patient population.
Dr. Vogel reported no conflicts of interest and no outside sources of funding.