Performance of current claims-based approaches to identify aortic dissection hospitalizations

Using Administrative Data to Better Treat Chronic Limb Threatening Ischemia

Chronic limb threatening ischemia (CLTI) is the most severe manifestation of peripheral arterial disease and represents a particularly high-risk subgroup of patients. As such, efforts to better understand this complex patient population through well-designed clinical research studies are critical to improving CLTI care. Prospective randomized clinical trials (RCTs) remain the gold standard in clinical research, but these trials are resource-intensive and have highly selective patient populations, which limit their feasibility and generalizability. Alternatively, retrospective studies are less expensive than RCTs, have a larger sample size, and are more generalizable owing to a broader patient population. Health care administrative data provide rich sources of information that may be used for research purposes and are increasingly being used for the study of vascular surgery conditions, including CLTI. Although administrative data are collected for billing purposes, they may be leveraged to study a broad range of topics in vascular surgery including those related to health care delivery, epidemiology, health disparities, and outcomes. This review provides an overview of administrative data available for CLTI research, the strengths and limitations of these data sources, current areas of investigation, and future opportunities for further study with the goal of improving outcomes in this high-risk population.

Neighborhood Socioeconomic Status and Readmission in Acute Type A Aortic Dissection Repair

INTRODUCTION

We examined the association of socioeconomic status as defined by median household income quartile (MHIQ) with mortality and readmission patterns following open repair of acute type A aortic dissection (ATAAD) in a nationally representative registry.

METHODS

Adults who underwent open repair of ATAAD were selected using the US Nationwide Readmissions Database and stratified by MHIQ. Patients were selected based on diagnostic and procedural codes. The primary endpoint was 30-d readmission.

RESULTS

Between 2016 and 2019, 10,288 individuals (65% male) underwent open repair for ATAAD. Individuals in the lowest income quartile were younger (median: 60 versus 64, P < 0.05) but had greater Elixhauser comorbidity burden (5.9 versus 5.7, P < 0.05). Across all groups, in-hospital mortality was approximately 15% (P = 0.35). On multivariable analysis adjusting for baseline comorbidity burden, low socioeconomic status was associated with increased readmission at 90 d, but not at 30 d. Concomitant renal disease (odds ratio [OR], 1.68; P < 0.001), pulmonary disease (OR, 1.26; P < 0.001), liver failure (OR 1.2, P = 0.04), and heart failure (OR, 1.17; P < 0.001) were all associated with readmission at 90 d. The primary indication for readmission was most commonly cardiac (33%), infectious (16.5%), and respiratory (9%).

CONCLUSIONS

In patients who undergo surgery for ATAAD, lower MHIQ was associated with higher odds of readmission following open repair. While early readmission for individuals living in the lowest income communities is likely attributable to greater baseline comorbidity burden, we observed that 90-d readmission rates are associated with lower MHIQ regardless of comorbidity burden. Further investigation is required to determine which patient-level and system-level interventions are needed to reduce readmissions in the immediate postoperative period for resource poor areas.

Nationwide database analysis of one-year readmission rates after open surgical or thoracic endovascular repair of Stanford Type B aortic dissection

OBJECTIVE

We examined readmissions and resource use during the first postoperative year in patients who underwent thoracic endovascular aortic repair or open surgical repair of Stanford type B aortic dissection.

METHODS

The Nationwide Readmissions Database (2016-2018) was queried for patients with type B aortic dissection who underwent thoracic endovascular aortic repair or open surgical repair. The primary outcome was readmission during the first postoperative year. Secondary outcomes included 30-day and 90-day readmission rates, in-hospital mortality, length of stay, and cost. A Cox proportional hazards model was used to determine risk factors for readmission.

RESULTS

During the study period, type B aortic dissection repair was performed in 6456 patients, of whom 3517 (54.5%) underwent thoracic endovascular aortic repair and 2939 (45.5%) underwent open surgical repair. Patients undergoing thoracic endovascular aortic repair were older (63 vs 59 years; P < .001) with fewer comorbidities (Elixhauser score of 11 vs 17; P < .001) than patients undergoing open surgical repair. Thoracic endovascular aortic repair was performed electively more often than open surgical repair (29% vs 20%; P < .001). In-hospital mortality was 9% overall and lower in the thoracic endovascular aortic repair cohort than in the open surgical repair cohort (5% vs 13%; P < .001). However, the 90-day readmission rate was comparable between the thoracic endovascular aortic repair and open surgical repair cohorts (28% vs 27%; P = .7). Freedom from readmission for up to 1 year was also similar between cohorts (P = .6). Independent predictors of 1-year readmission included length of stay more than 10 days (P = .005) and Elixhauser comorbidity risk index greater than 4 (P = .033).

CONCLUSIONS

Approximately one-third of all patients with type B aortic dissection were readmitted within 90 days after aortic intervention. Surprisingly, readmission during the first postoperative year was similar in the open surgical repair and thoracic endovascular aortic repair cohorts, despite marked differences in preoperative patient characteristics and interventions.

Trends and Outcomes of Elective Thoracic Aortic Repair and Acute Thoracic Aortic Syndromes in the United States

BACKGROUND

There is a paucity of data on the contemporary outcomes and trends of elective thoracic aortic aneurysm repair and aneurysm-associated acute aortic syndrome.

METHODS

We queried the National Inpatient Sample (NIS) database years 2012-2016 to identify hospitalizations for elective thoracic aortic aneurysm repair and aneurysm-associated acute aortic syndrome. The main study outcome was in-hospital mortality.

RESULTS

The analysis yielded 24,295 hospitalizations for elective thoracic aortic aneurysm repair and 8875 hospitalizations for aneurysm-associated acute aortic syndrome. The number of hospitalizations for elective aortic repair significantly increased from 4375 in 2012 to 5450 in 2016 (P_trend = .01). The number of hospitalizations for acute aortic syndrome numerically increased from 1545 in 2012 to 2340 in 2016 (P_trend = .10). Overall in-hospital mortality for elective aortic repair was 2.4% with no change over time. In-hospital mortality for acute aortic rupture was 39.4% and for acute aortic dissection was 6.2% with no change over time. Hospitalizations for elective aortic repair had lower incidence of complications compared with those for aneurysm-associated acute aortic syndrome, including cardiogenic shock, cardiac arrest, acute stroke, and shorter length of stay. Factors associated with higher mortality among admissions undergoing elective aortic repair included older age, heart failure, valvular disease, and chronic kidney disease. Older age, coagulopathy, and fluid/ electrolytes disorders were associated with increased mortality among those with acute aortic syndrome.

CONCLUSION

Contemporary elective thoracic aortic aneurysm repair is associated with lower in-hospital mortality and morbidity when compared with a clinical presentation for an aneurysm-associated acute aortic syndrome. This should be taken into account when deciding the timing of elective aortic aneurysm repair and balancing the risks and benefits.

Epidemiology of aortic dissection

Aortic dissection remains a highly morbid diagnosis. The treatment of aortic dissection has undergone several paradigm shifts since it was first understood. However, despite the robust research in treatment, the epidemiology of aortic dissection is limited. In this review, we discuss the historical perspectives of aortic dissection with a review of risk factors and presentation. We review the trends in incidence during the past 40 years, with consideration for sex, race, and ethnicity in admission. We further focus our discussion of the classically described Type B aortic dissection treatment. Lastly, we review the impact of long-term events, readmissions, cost assessments, and quality of life studies of patients with aortic dissection. Care for those with aortic dissection remains a long-term challenge for providers and a multispecialty approach is needed for complete patient management.

Association of Fluoroquinolones With the Risk of Aortic Aneurysm or Aortic Dissection

IMPORTANCE

Previous observational studies have suggested that fluoroquinolones are associated with aortic aneurysm or dissection, but these studies may be subject to confounding by indication or surveillance bias.

OBJECTIVE

To assess the association of fluoroquinolones with risk of aortic aneurysm or aortic dissection (AA/AD) while accounting for potential confounding by fluoroquinolone indication and bias owing to differential surveillance.

DESIGN, SETTING, AND PARTICIPANTS

In an observational cohort study using a US commercial claims database, 2 pairwise 1:1 propensity score-matched cohorts were identified: patients aged 50 years or older with a diagnosis of pneumonia 3 days or less before initiating treatment with a fluoroquinolone or azithromycin and patients aged 50 years or older with a urinary tract infection (UTI) diagnosis 3 days or less before initiating a fluoroquinolone or combined trimethoprim and sulfamethoxazole. Hazard ratios (HRs) and 95% CIs were estimated controlling for 85 baseline confounders. In a secondary analysis, patients receiving fluoroquinolones were compared with those receiving amoxicillin, both with and without considering baseline aortic imaging, to address differences in detection of AA/AD before antibiotic use. Data on patients within the database from January 1, 2003, through September 30, 2015, were analyzed. Data analysis was conducted from July 23, 2019, to July 6, 2020.

MAIN OUTCOMES AND MEASURES

Hospitalization for AA/AD occurring within 60 days following treatment initiation.

RESULTS

After propensity score matching, patient characteristics were well balanced, with 279 554 patients (mean [SD] age, 63.66 [10.93] years; 149 976 women [53.6%]) in the pneumonia cohort and 948 364 patients (mean [SD] age, 62.06 [10.33] years; 823 667 women [86.9%]) in the UTI cohort. Initiators of fluoroquinolones (n = 139 772 pairs in the pneumonia cohort and n = 474 182 pairs in the UTI cohort) had an increased rate of AA/AD compared with initiators of azithromycin (HR, 2.57; 95% CI, 1.36-4.86; incidence, 0.03% for fluoroquinolones vs 0.01% for azithromycin) but no increased rate compared with initiators of combined trimethoprim and sulfamethoxazole (HR, 0.99; 95% CI, 0.62-1.57; incidence, <0.01% in both UTI groups). Secondary analysis using amoxicillin as a comparator (n = 3 976 162 pairs) produced results consistent with those from earlier studies (HR, 1.54; 95% CI, 1.33-1.79; incidence, <0.01% in both groups). Requiring baseline imaging in this cohort (n = 542 649 pairs) to address surveillance bias attenuated the increased rate (HR, 1.13; 95% CI, 0.96-1.33; incidence, 0.06% for fluoroquinolones vs 0.05% for amoxicillin).

CONCLUSIONS AND RELEVANCE

The findings of this nationwide cohort study of adults with pneumonia or UTI suggest an increased relative rate of AA/AD associated with fluoroquinolones within the pneumonia cohort but not within the UTI cohort. In both cohorts, the absolute rate of AA/AD appeared to be low (<0.1%). The increased relative rate observed in the pneumonia cohort may be due to residual confounding or surveillance bias.

Burden and causes of readmissions following initial discharge after aortic syndromes

BACKGROUND

Aortic syndromes, including aortic dissection (AD), intramural hematoma (IMH), and penetrating aortic ulcer (PAU), carry significant morbidity and mortality; few data exist regarding burden and causes of related rehospitalizations following initial discharge.

METHODS

The study was conducted using the Rochester Epidemiology Project. All adult residents (age ≥18 years) with an incident diagnosis of AD, IMH, and PAU (1995-2015) were identified from the Rochester Epidemiology Project using the International Classification of Diseases, Ninth Revision and Tenth Revision codes and Hospital Adaptation of the International Classification of Diseases, second edition, codes. Assessment of any-cause (aortic and cardiovascular), aorta-related, or cardiovascular-related readmissions was determined following date of hospital discharge or diagnosis date (ie, the index event).

RESULTS

A total of 117 patients of 130 cases of AD, IMH, and PAU included in the initial study population survived the index event and were evaluated. The median age of diagnosis was 74 years, and 70 (60%) were male. A total of 79 patients (68%) experienced at least one readmission. The median time to first any-cause, cardiovascular, and aortic readmission was 143, 861, and 171 days, respectively. The cumulative incidence of any-cause readmissions at 2, 4, and 10 years was 45%, 55%, and 69%, respectively. The cumulative incidence of cardiovascular readmissions at 2, 4, and 10 years was 15%, 20%, and 28%, respectively. The cumulative incidence of aortic readmissions at 2, 4, and 10 years was 38%, 46%, and 59%, respectively. Overall survival for the entire cohort at 2, 4, and 10 years was 84%, 75%, and 50%, respectively.

CONCLUSIONS

Readmissions following initial discharge after diagnosis of aortic syndrome are common and not different across specific disease types. Whereas aorta-related rehospitalizations occur in more than half of patients but tend to be earlier, cardiovascular-related rehospitalizations tend to happen later in about one-third of patients. This may suggest the need for early follow-up focused on aortic complications, whereas later follow-up should address cardiovascular events.

Impact of patient factors and procedure on readmission after aortic dissection admission in the states of Florida and New York

BACKGROUND

Readmissions after aortic dissection (AD) admission are not well described. Using state-based administrative claims data, we sought to define readmission rates after AD and to identify factors associated with them.

METHODS

State Inpatient Databases for Florida (2007-2012) and New York (2008-2012) were queried for AD index admissions. Admissions were stratified by initial treatment strategy: type A open surgery repair (TAOR), type B open surgery repair (TBOR), thoracic endovascular aortic repair (TEVAR), or medical management (MM). All-cause readmission rates were calculated at 30 days, 90 days, and 2 years. Logistic regression was used to identify factors associated with readmission at each time point for all type A admissions (TAOR) or type B admissions (TBOR, TEVAR, MM).

RESULTS

We identified 4670 patients with an AD index admission. Treatment was with TAOR in 1031 (22%), TBOR in 761 (16%), TEVAR in 412 (9%), and MM in 2466 (53%). Patients were predominantly male (59.4%) and white (61.9%), with a median age of 66 years. Overall mortality during AD index admission was 14.8% (TAOR, 15.8%; TBOR, 17.1%; TEVAR, 9.0%; MM, 14.7%; P = .002 across all groups). All-cause readmission rates were similar across treatment groups at 30 days (9.6%-11%; P = .56), 90 days (15.2%-20%; P = .26), and 2 years (49.2%-54.4%; P = .15). Higher income quartile (vs lowest) was associated with lower odds of early readmission (at 30 days and 90 days) after type B admissions but not after type A admissions. At 2 years, self-pay (vs Medicare) was associated with lower odds of readmission in both type A and type B admissions, whereas higher comorbidity count and black race (vs white) were associated with higher odds of readmission. TEVAR (vs MM) was also associated with higher odds of readmission. Cardiovascular disease was the most common cause for readmission at all time points. Emergency department readmission counts were highest after MM admissions, and ambulatory surgical admissions were highest after TBOR. Both TEVAR and MM initial costs were lower than TAOR and TBOR costs, but at 2 years, costs remained significantly lower only for MM.

CONCLUSIONS

In-state 30-day, 90-day, and 2-year readmission rates after AD were not associated with initial treatment type. Two-year readmissions are common. Strategies to target socioeconomic, race, and geographic factors may reduce variations in readmission patterns after AD admission.