Race and Socioeconomic Disparities in Proximal Aortic Surgery

BACKGROUND

Substantial socioeconomics-based disparities exist in cardiac surgery. Although there are robust data for revascularization and valve procedures, the effect of race and socioeconomic status on proximal aortic surgery is not well studied. This study analyzed the impact of race and socioeconomic status on in-hospital outcomes after proximal aortic surgery.

METHODS

All adult patients who underwent proximal aortic surgery for aortic dissection or thoracic aneurysm from the 2016 to 2018 National Inpatient Sample were included. Primary outcomes included in-hospital mortality and in-hospital composite morbidity (stroke, pulmonary embolus, major bleeding, acute kidney injury, or permanent pacemaker insertion). Adjusted outcomes were assessed with multivariable analysis.

RESULTS

A weighted total of 32,895 patients were included; 25,461 (77.4%) classified as White, 3224 (9.8%) Black, 2039 (6.2%) Hispanic, and 2171 (6.6%) other. Black and Hispanic patients had significantly lower median household income, higher proportion of self-pay insurance status, younger age, higher comorbidity burden, and a higher proportion of urgent or emergency procedures compared with White patients. There was no significant difference in observed in-hospital mortality by patient race, but non-White patients had significantly higher composite morbidity. On adjusted analysis, there was no difference in in-hospital mortality, but non-White race was an independent predictor of in-hospital morbidity (adjusted odds ratio, 1.6; 95% CI, 1.4-1.8; P < .001).

CONCLUSIONS

Patients of non-White race who undergo proximal aortic surgery have less insurance coverage, more urgent procedures, and a higher comorbidity burden than White patients, disparities that translate to significantly higher morbidity in non-White. A greater focus on nonfatal outcome differentials and improving access to care likely will improve aortic surgery disparities.

The Impact of Frailty on Outcomes of Proximal Aortic Aneurysm Surgery: A Nationwide Analysis

(1) Background: This study examines frailty's impact on proximal aortic surgery outcomes. (2) Methods: All patients with a thoracic aortic aneurysm who underwent aortic root, ascending aorta, or arch surgery from the 2016-2017 National Inpatient Sample were included. Frailty was defined by the Adjusted Clinical Groups Frailty Indicator. Outcomes of interest included in-hospital mortality and a composite of death, stroke, acute kidney injury (AKI), and major bleeding (MACE). (3) Results: Among 5745 patients, 405 (7.0%) met frailty criteria. Frail patients were older, with higher rates of chronic pulmonary disease, diabetes, and chronic kidney disease. There was no difference in in-hospital death (4.9% vs. 2.4%, p = 0.169); however, the frail group exhibited higher rates of stroke and AKI. Frail patients had a longer length of stay (17 vs. 8 days), and higher rates of non-home discharge (74.1% vs. 54.3%) than non-frail patients (both p < 0.001). Sensitivity analysis confirmed increased morbidity and mortality in frail individuals. After adjusting for patient comorbidities and hospital characteristics, frailty independently predicted MACE (OR 4.29 [1.88-9.78], p = 0.001), while age alone did not (OR 1.00 [0.99-1.02], p = 0.568). Urban teaching center status predicted a lower risk of MACE (OR 0.27 [0.08-0.94], p = 0.039). (4) Conclusions: Frailty is associated with increased morbidity in proximal aortic surgery and is a more significant predictor of mortality than age. Coordinated treatment in urban institutions may enhance outcomes for this high-risk group.

Bicuspid Aortopathy does NOT Require Earlier Surgical Intervention

OBJECTIVES

Guidelines for surgical correction of ascending thoracic aortic aneurysm (ATAA) in bicuspid aortic valve (BAV) patients have oscillated back and forth over the years. In this study, we outline the natural history of the ascending aorta in BAV and TAV (trileaflet aortic valve) ATAA patients followed over time, to ascertain if their behavior differs, and to determine if a different threshold for intervention is required.

METHODS

Aortic diameters and long-term complications (adverse aortic events; AAE) of 2428 patients (554 BAV and 1874 TAV) with ATAA prior to operative repair were reviewed. Growth rates, yearly complication rates, event-free survival (Kaplan-Meier), and risk of complications as a function of aortic size (regression analyses) were calculated. Long-term follow-up and precise cause of death granularity was achieved via a comprehensive six-pronged approach.

RESULTS

Aortic growth rate in BAV- vs. TAV-ATAA patients was 0.20 and 0.17 cm/year, respectively (p=0.009), with the rate increasing with increasing aortic size. Yearly AAE rates increased with ATAA size and were lower for BAV patients. The relative risk of AAE exhibited an exponential increase with aortic diameter. BAV patients had a lower all-cause and ascending aorta specific AAE hazard. Age-adjusted 10-year event free survival was significantly better for BAV patients, and BAV emerged as a protective factor against type A dissection, rupture, and ascending aortic death.

CONCLUSION

The threshold for surgical repair of ascending aneurysm with BAV should not differ from that of TAV. Prophylactic surgery should be considered at 5.0cm for TAV (and BAV) patients at expert centers.

Bovine Aortic Arch: A Result of Chance or Mandate of Inheritance?

Previous studies have shown that bovine arch incidence is higher in patients with thoracic aortic aneurysms than in patients without an aneurysm. Although thoracic aortic aneurysm disease is known to be familial in some cases, it remains unknown if bovine arch results from a genetic mutation, thus allowing it to be inherited. Our objective was to determine the heritability of bovine arch from phenotypic pedigrees. We identified 24 probands from an institutional database of 202 living patients with bovine arch who had previously been diagnosed with thoracic aortic aneurysm and who had family members with previous chest computed tomography or magnetic resonance imaging scans. Aortic arch configuration of all first-degree and second-degree relatives was determined from available scans. Heritability of bovine arch was estimated using maximum-likelihood-based variance decomposition methodology implemented by way of the SOLAR package (University of Maryland, Catonsville, Maryland). 43 relatives of 24 probands with bovine arch had preexisting imaging available for review. The prevalence of bovine arch in relatives with chest imaging was 53% (n = 23) and did not differ significantly by gender (male: 64.3%, female: 55.6%, p = 1). The bovine arch was shown to be highly heritable with a heritability estimate (h²) of 0.71 (p = 0.048). In conclusion, the high heritability of bovine arch in our sample population suggests a genetic basis.

Association Between Cardiac Surgeons' Number of Years in Practice and Surgical Outcomes in New York Cardiac Centers

IMPORTANCE

More than half of US cardiothoracic surgeons are older than 55 years, and the association between surgeon number of years in practice and surgical outcomes remains unclear.

OBJECTIVE

To assess the association between cardiac surgeons' time in practice and operative outcomes for coronary artery bypass grafting (CABG) and valve surgery.

DESIGN, SETTING, AND PARTICIPANTS

Cross-sectional analysis performed of surgeon-level outcomes data from the 2014-2016 New York State Cardiac Data Reporting System across the 38 New York cardiac surgery centers. Years in practice were characterized as early career (<10 years) and late career (≥10 years). Participants were 120 cardiothoracic surgeons who performed CABG and 112 cardiothoracic surgeons who performed valve procedures between 2014 and 2016. Data were analyzed in April 2020. Surgeons who trained outside of the United States or had unclear training history were excluded.

MAIN OUTCOMES AND MEASURES

Risk-adjusted operative mortality rate (RAMR). Mortality was defined as all-cause death within 30 days of surgery or within the index hospitalization, whichever was longer. Risk adjustment was performed by a multivariable risk model developed by the New York State Department of Public Health. Restricted cubic spline curve identified the association between risk-adjusted mortality rate and surgeon number of years in practice. Linear regression models adjusted for surgeons' annual case volumes.

RESULTS

A total of 112 CABG surgeons and 120 valve surgeons performed 39 436 CABG and 18 596 valve procedures between 2014 and 2016. The median number of surgeon years in practice was 20.0 (interquartile range [IQR], 12.0-28.5) years. The median surgeon annual case volume was 160.0 (IQR, 92.5-245.0) for CABG procedures and 104.0 (IQR, 43.0-210.0) for valve procedures. The median RAMR was 1.3% (IQR, 0.2%-2.2%) for CABG procedures and 3.1% (IQR, 1.7%-5.1%) for valve procedures. Surgeons with less than 10 years of practice had higher RAMR for valve procedures compared with surgeons with more than 10 years of practice (4.0 [IQR, 1.5-7.7] vs 2.9 [IQR, 1.7-4.7]; P = .20), but the finding was not statistically signficant. The RAMR for surgeons with less than 10 years of practice was similar compared with surgeons with more than 10 years of practice for CABG procedures (1.3 [IQR, 0.3-2.1] vs 1.3 [IQR, 0.0-2.2]; P = .73). A lower number of years in practice was significantly associated with higher RAMR for valve procedures (RAMR estimates for linear term: -1.144; 95% CI, -1.955 to -0.332; P = .006; quadratic term: 0.059; 95% CI, 0.015 to 1.102; P = .008; and cubic term: -0.001; 95% CI, -0.002 to 0.000; P = .01). This association was not observed for CABG.

CONCLUSIONS AND RELEVANCE

In this cross-sectional study, compared with late-career cardiac surgeons, early-career cardiac surgeons were associated with worse risk-adjusted outcomes for valve operations but not for CABG. This finding suggests certain competence deficiency for valve surgery early after finishing training in cardiac surgery.

Genes Associated with Thoracic Aortic Aneurysm and Dissection: 2019 Update and Clinical Implications

Thoracic aortic aneurysm is a typically silent disease characterized by a lethal natural history. Since the discovery of the familial nature of thoracic aortic aneurysm and dissection (TAAD) almost 2 decades ago, our understanding of the genetics of this disorder has undergone a transformative amplification. To date, at least 37 TAAD-causing genes have been identified and an estimated 30% of the patients with familial nonsyndromic TAAD harbor a pathogenic mutation in one of these genes. In this review, we present our yearly update summarizing the genes associated with TAAD and the ensuing clinical implications for surgical intervention. Molecular genetics will continue to bolster this burgeoning catalog of culprit genes, enabling the provision of personalized aortic care.

Left Atrial to Femoral Artery Full Cardiopulmonary Bypass: A Novel Technique for Descending and Thoracoabdominal Aortic Surgery

Left atrial-femoral artery (LA-FA) bypass with a centrifugal pump and no oxygenator is commonly used for descending and thoracoabdominal aortic (DTAA) operations, mitigating the deleterious effects of cross-clamping. We present our initial experience performing DTAA replacement under LA-FA (left-to-left) cardiopulmonary bypass (CPB) with an oxygenator. DTAA replacement under LA-FA bypass with an oxygenator was performed in 14 consecutive patients (CPB group). The pulmonary vein and femoral artery (or distal aorta) were cannulated and the full CPB machine were used, including oxygenator, roller pump, pump suckers, and kinetically enhanced drainage. The CPB group was compared with 50 consecutive patients who underwent DTAA replacement utilizing traditional LA-FA bypass without an oxygenator (LA-FA group). Perioperative data were collected and statistical analyses were performed. All CPB patients maintained superb cardiopulmonary stability. The pump sucker permitted immediate salvage and return of shed blood. Superb oxygenation was maintained at all times. High-dose full CPB heparin was reversed without difficulty. The CPB group required markedly fewer blood transfusions than the LA-FA group (2.21 vs. 5.88 units, p  < 0.004). The 30-day mortality rate was 7.1% ( n  = 1) and there were no paraplegia cases in the CPB group versus 7 (14%) deaths and 3 (6%) paraplegia cases in the LA-FA group. Traditional LA-FA bypass without an oxygenator avoids high-dose heparin. In the present era, heparin reversal is more secure. Our experience finds that the novel application of LA-FA CPB with an oxygenator is safe and suggests improved hemodynamics (immediate return of shed blood) and a hemostatic advantage (avoidance of loss of coagulation factors in the cell saver).

Natural history of descending thoracic and thoracoabdominal aortic aneurysms

OBJECTIVES

Elucidating critical aortic diameters at which natural complications (rupture, dissection, and death) occur is of paramount importance to guide timely surgical intervention. Natural history knowledge for descending thoracic and thoracoabdominal aortic aneurysms is sparse. Our small early studies recommended repairing descending thoracic and thoracoabdominal aortic aneurysms before a critical diameter of 7.0 cm. We focus exclusively on a large number of descending thoracic and thoracoabdominal aortic aneurysms followed over time, enabling a more detailed analysis with greater granularity across aortic sizes.

METHODS

Aortic diameters and long-term complications of 907 patients with descending thoracic and thoracoabdominal aortic aneurysms were reviewed. Growth rates (instrumental variables approach), yearly complication rates, 5-year event-free survival (Kaplan-Meier), and risk of complications as a function of aortic height index (aortic diameter [centimeters]/height [meters]) (competing-risks regression) were calculated.

RESULTS

Estimated mean growth rate of descending thoracic and thoracoabdominal aortic aneurysms was 0.19 cm/year, increasing with increasing aortic size. Median size at acute type B dissection was 4.1 cm. Some 80% of dissections occurred below 5 cm, whereas 93% of ruptures occurred above 5 cm. Descending thoracic and thoracoabdominal aortic aneurysm diameter 6 cm or greater was associated with a 19% yearly rate of rupture, dissection, or death. Five-year complication-free survival progressively decreased with increasing aortic height index. Hazard of complications showed a 6-fold increase at an aortic height index of 4.2 or greater compared with an aortic height index of 3.0 to 3.5 (P < .05). The probability of fatal complications (aortic rupture or death) increased sharply at 2 hinge points: 6.0 and 6.5 cm.

CONCLUSIONS

Acute type B dissections occur frequently at small aortic sizes; thus, prophylactic size-based surgery may not afford a means for dissection protection. However, fatal complications increase dramatically at 6.0 cm, suggesting that preemptive intervention before that criterion can save lives.

Nonsyndromic Thoracic Aortic Aneurysms and Dissections-Is Screening Possible?

Nonsyndromic thoracic aortic aneurysm and dissection (TAAD) account for 95% of all TAAD cases and comprise a subset in which the lack of obvious clinical signs makes diagnosis a challenge. Despite the potentially fatal natural history, timely diagnosis and prophylactic surgical intervention allow restoration of near-normal life expectancy in TAAD patients, underlining the critical importance of screening tests. To date, more than 30 TAAD disease-causing genes have been identified, and over 30% of nonsyndromic TAAD patients have a genetic mutation in 1 or more of these genes. Whole exome sequencing allows routine genetic testing in a clinical setting by screening for all TAAD-related genes, thus facilitating personalized aortic care. Additionally, increased vigilance upon diagnosis of certain TAAD-related diseases ("guilty associates") and the emergence of modern radiologic and novel serologic screening tests will further bolster efforts to detect undiagnosed asymptomatic nonsyndromic TAAD.