A shifting approach to management of the thoracic aorta in bicuspid aortic valve

Abstract

Objectives: The scientific understanding of aortic dilation associated with bicuspid aortic valve (BAV) has evolved during the past 2 decades, along with improvements in diagnostic technology and surgical management. We aimed to evaluate secular trends and predictors of thoracic aortic surgery among patients with BAV in the United States.

Methods: We used the 1998-2009 Nationwide Inpatient Sample, an administrative dataset representative of US hospital admissions, to identify hospitalizations for adults aged 18 years or more with BAV and aortic valve or thoracic aortic surgery. Covariates included age, gender, year, aortic dissection, endocarditis, thoracic aortic aneurysm, number of comorbidities, hospital teaching status and region, primary insurance, and concomitant coronary artery bypass surgery.

Results: Between 1998 and 2009, 48,736 ± 3555 patients with BAV underwent aortic valve repair or replacement and 1679 ± 120 patients with BAV underwent isolated thoracic aortic surgery. The overall number of surgeries increased more than 3-fold, from 4556 ± 571 in 1998/1999 to 14,960 ± 2107 in 2008/2009 (P < .0001). The proportion of aortic valve repair or replacement including concomitant thoracic aortic surgery increased from 12.8% ± 1.4% in 1998/1999 to 28.5% ± 1.6% in 2008/2009, which mirrored an increasing proportion of patients with a diagnosis of thoracic aortic aneurysm. Mortality was equivalent for patients undergoing aortic valve repair or replacement with thoracic aortic surgery and those undergoing isolated aortic valve repair or replacement (1.8% ± 0.3% vs 1.5% ± 0.2%; multivariable odds ratio, 1.02; 95% confidence interval, 0.67-1.57), with decreasing mortality over the study period (from 2.5% ± 0.6% in 1998/1999 to 1.5% ± 0.2% in 2008/2009; multivariable odds ratio per 2-year increment, 0.89; 95% confidence interval, 0.81-0.99; P = .03). Total charges for BAV surgical hospitalizations increased more than 7.5-fold from approximately $156 million in 1998 to $1.2 billion in 2009 (inflation-adjusted 2009 dollars).

Conclusions: There was a marked increase in the use of thoracic aortic surgery among patients with BAV.

Keywords: 20.2; 26.1; ACC; AHA; AVR; American College of Cardiology; American Heart Association; BAV; CI; OR; TAA; TAS; aortic valve repair or replacement; bicuspid aortic valve; confidence interval; odds ratio; thoracic aortic aneurysm; thoracic aortic surgery.

FIGURE 1

The number of surgical procedures performed in patients with BAV in the United States from 1998 to 2009, stratified by procedure type. There was an increase in the overall number of AVR and TAS among patients with BAV in the United States over time. This increase was most marked for patients undergoing AVR and concomitant TAS. AVR, Aortic valve repair or replacement; TAS, thoracic aortic surgery; BAV, bicuspid aortic valve.

FIGURE 2

Temporal trend in the proportion of hospitalizations in which patients with BAV receiving AVR underwent concomitant TAS (% ± standard error %), 1998-2009. The increase in aortic surgery was closely paralleled by an increase in diagnosis of TAA (dotted line). SE, Standard error.

FIGURE 3

Subgroup analysis of the proportion of patients undergoing AVR that included concomitant TAS for each time epoch. A, Patients aged less than 50 years or 50 or more years. A greater proportion of younger patients underwent aortic surgery, at an increasing frequency of the study duration. B, Gender. Men more frequently underwent aortic surgery, at an increasing frequency of the study duration. C, Type of hospital. Concomitant aortic surgery was performed more frequently at teaching hospitals, at an increasing frequency of the study duration. Nonteaching hospitals did not show a similar trend to perform concomitant aortic surgery over the study duration. There seemed to be a more consistent and prominent trend to a greater proportion of aortic surgeries in teaching hospitals.

FIGURE 4

In-hospital mortality, by 2-year time period, for patients undergoing isolated AVR and patients undergoing concomitant TAS. There was a trend toward lower mortality over time for all groups. Data for isolated TAS are not shown because of the smaller number of cases/deaths, as well as distinct patient characteristics (ie, higher dissection and coarctation frequency). Error bars represent standard error %. AVR, Aortic valve replacement or repair; TAS, thoracic aortic surgery.