Long-term outcomes of aortic root operations in the United States among Medicare beneficiaries

OBJECTIVE

The best method of aortic root repair in older patients remains unknown given a lack of comparative effectiveness of long-term outcomes data. The objective of this study was to compare long-term outcomes of different surgical approaches for aortic root repair in Medicare patients using The Society of Thoracic Surgeons Adult Cardiac Surgery Database-Centers for Medicare & Medicaid Services-linked data.

METHODS

A retrospective cohort study was performed by querying the Society of Thoracic Surgeons Adult Cardiac Surgery Database for patients aged 65 years or more who underwent elective aortic root repair with or without aortic valve replacement. Primary long-term end points were mortality, any stroke, and aortic valve reintervention. Short-term outcomes and long-term survival were compared among each root repair strategy. Additional risk factors for mortality after aortic root repair were assessed with a multivariable Cox proportional hazards model.

RESULTS

A total of 4173 patients aged 65 years or more underwent elective aortic root repair. Patients were stratified by operative strategy: mechanical Bentall, stented bioprosthetic Bentall, stentless bioprosthetic Bentall, or valve-sparing root replacement. Mean follow-up was 5.0 (±4.6) years. Relative to mechanical Bentall, stented bioprosthetic Bentall (adjusted hazard ratio, 0.80; confidence interval, 0.66-0.97) and stentless bioprosthetic Bentall (adjusted hazard ratio, 0.70; confidence interval, 0.59-0.84) were associated with better long-term survival. In addition, stentless bioprosthetic Bentall (adjusted hazard ratio, 0.64; confidence interval, 0.47-0.80) and valve-sparing root replacement (adjusted hazard ratio, 0.51; confidence interval, 0.29-0.90) were associated with lower long-term risk of stroke. Aortic valve reintervention risk was 2-fold higher after valve-sparing root replacement compared with other operative strategies.

CONCLUSIONS

In the Medicare population, there was poorer late survival and greater late stroke risk for patients undergoing mechanical Bentall and a higher rate of reintervention for valve-sparing root replacement. Bioprosthetic Bentall may be the procedure of choice in older patients undergoing aortic root repair, particularly in the era of transcatheter aortic valve replacement.

Midterm Outcomes of Endovascular Repair of Aortic Arch Aneurysms with the Gore Thoracic Branch Endoprosthesis

OBJECTIVE

Aortic aneurysms involving aortic arch vessels are anatomically unsuitable for standard thoracic endovascular repair (TEVAR) without cervical debranching of the arch vessels. Three year outcomes of a single branched thoracic endograft following previous publication of peri-operative and one year outcomes are reported.

METHODS

This was a multicentre feasibility trial of the GORE TAG Thoracic Branch Endoprosthesis (TBE), a thoracic endovascular graft incorporating a single retrograde branch for aortic arch vessel perfusion. The first study arm enrolled patients with an intact descending thoracic aortic aneurysm extending to the distal arch with left subclavian artery (LSA) incorporation (zone 2). The second arm enrolled patients with arch aneurysms requiring incorporation of the left carotid or innominate artery (zone 0/1) and extra-anatomic surgical revascularisation of the remaining aortic arch vessels. Outcomes at three years are reported.

RESULTS

The cohort comprised 40 patients (31 zone 2, nine zone 0/1). The majority were male (52%). Mean follow up was 1 408 ± 552 days in the zone 2 and 1 187 ± 766 days in the zone 0/1 cohort. During three year follow up there was no device migration, fracture, or aortic rupture in either arm. In the zone 2 arm, freedom from re-intervention was 97% at one and three years but there were two side branch occlusions. Two patients had aneurysm enlargement > 5 mm without documented endoleak or re-intervention. Freedom from death at one and three years was 90% and 84%. In the zone 0/1 arm there were no re-interventions, loss of branch patency, or aneurysm enlargement at three years. Cerebrovascular events occurred in three patients during follow up: two unrelated to the device or procedure, and one of unknown relationship. Two patients in this arm died during the follow up period, both unrelated to the procedure or the aneurysm.

CONCLUSION

Initial three year results of the TBE device for endovascular repair of arch aneurysms show favourable patency and durability with low rates of graft related complications.

The Penn Classification System For Malperfusion In Acute Type A Dissection: A 25 Year Experience

BACKGROUND

The University of Pennsylvania classification system (Penn class) of acute type A aortic dissection (aTAAD) is used to evaluate the impact of malperfusion on surgical outcomes. The purpose of this analysis was to determine the validity of Penn class in a larger and more contemporary cohort and to compare its performance with other classification systems.

METHODS

This was a retrospective study of patients who underwent aTAAD repair at our institution from 1993 to 2020. Patients were assigned to Penn class on the basis of burden of preoperative malperfusion syndrome. The association of Penn class and 30-day mortality was evaluated by multivariable regression. The discriminatory ability of Penn class for mortality was determined by a bootstrapped C statistic.

RESULTS

There were 1192 patients, of whom 50% were assigned to Penn class A (no ischemia), 21% (253/1192) to class B (local ischemia), 14% (171/1192) to class C (generalized ischemia), and 14% (167/1192) to class B-C (combined ischemia). The incidence of mortality rose significantly with increasing Penn class from 5% (31/601) in class A to 35% (59/167) in class B-C (P < .001). After adjustment, 30-day mortality increased significantly with class B (odds ratio [OR], 2.43; 95% CI, 1.38-4.27), class C (OR, 3.39; 95% CI, 1.90-6.03), and class B-C (OR, 13.08; 95% CI, 7.90-22.15) compared with class A. The C statistic was 0.77 (95% CI, 0.72-0.80) and was significantly higher than for models featuring alternative classification systems (P < .05).

CONCLUSIONS

Penn class provides excellent discrimination for 30-day mortality after repair of aTAAD.

National Adherence to Medical Management of Aortic Aneurysms

OBJECTIVES

The purpose of this study was to describe levels of adherence to guideline-based medical management in patients with aortic aneurysms, using an analogous population with coronary artery disease as a comparator. Adherence among those with aortic aneurysms has never been studied.

METHODS

Adult patients with an aortic aneurysm or coronary artery disease diagnosed between 2004 and 2018 in the Optum Clinformatics deidentified Datamart were queried. Aneurysms were subclassified as thoracic, abdominal, or both. Receipt of an antihypertensive or antihyperlipidemic was determined through pharmacy claims. Adherence was determined as receipt of the indicated pharmacologic(s) after a diagnosis of aneurysm or coronary artery disease. Adherence was compared between those with aneurysms and coronary disease using univariable logistic regression.

RESULTS

After exclusions, 194,144 patients with an aortic aneurysm and 3,946,782 with coronary artery disease were identified. Overall adherence was low (45.0%) and differed significantly by aneurysm subtype: highest in isolated thoracic (45.9%) and lowest in isolated abdominal aneurysms (42.6%). Adherence levels declined significantly after 1 year by about 15% in each aneurysm subtype. All subtypes of aneurysm had a significantly lower odds of adherence compared to those with coronary disease with odds ranging from 0.61 in those with isolated abdominal aneurysms to 0.80 with isolated thoracic aneurysms.

CONCLUSIONS

Adherence among those with aortic aneurysms is very low, differs by subtype, and declines with time. Levels of adherence in those with aortic aneurysms is significantly lower compared to those with coronary artery disease. This should prove a reasonable target for implementation initiatives.

PROSE: Prospective Randomized Trial of the On-X Mechanical Prosthesis and the St Jude Medical Mechanical Prosthesis Evaluation: Part 2: Study results-prostheses, positions, and economic development

Objectives

The Prospective Randomized On-X Mechanical Prosthesis Versus St Jude Medical Mechanical Prosthesis Evaluation (PROSE) trial purpose was to investigate whether a current-generation mechanical prosthesis (On-X; On-X Life Technologies/Artivion Inc) reduced the incidence of thromboembolic-related complications compared with a previous-generation mechanical prosthesis (St Jude Medical Mechanical Prosthesis; Abbott/St Jude Medical). This second report documents the valve-related complications by individual prostheses and by Western and Developing populations.

Methods

The PROSE trial study was conducted in 28 worldwide centers and incorporated 855 subjects randomized between 2003 and 2016. The study enrollment was discontinued on August 31, 2016. The study protocol, and analyses of 10 demographic variables and 24 risk factors were published in detail in 2021.

Results

The total patient population (N = 855) included patients receiving an On-X valve (n = 462) and a St Jude Medical valve (n = 393). The overall freedom evaluation showed no differences at 5 years between the prostheses for thromboembolism or for valve thrombosis. There were also no differences in mortality. There were several differences between Developing and Western populations. The freedom relations at 5 years for mortality favored Western over Developing populations. Valve thrombosis was differentiated by position and site: aortic < mitral (P = .007) and Western < Developing (P = .005). In the mitral position there were no cases in Western populations, whereas there were 8 in Developing populations (P = .217).

Conclusions

The On-X valve and St Jude Medical valve performed equally well in the study with no differences found. The only differentiation occurred with valve thrombosis in the mitral position more than the aortic position and occurring in Developing more than Western populations. The occurrence of valve thrombosis was also related to a younger population possibly due to anticoagulation compliance based on record review.

Valve-sparing Root Reimplantation In Patients With Left Ventricular Dilation

OBJECTIVES

The purpose of this study was to evaluate the association between left ventricular (LV) dilation and outcomes following valve-sparing root reimplantation.

METHODS

Patients with an indexed left ventricular internal diameter during systole (iLVIDS) of ≥ 2.0 cm/m2 were categorized as having LV dilation. Outcomes were post-operative aortic insufficiency (AI), re-intervention, and all-cause mortality. The cumulative incidence of each outcome was computed using the Kaplan-Meier estimator. Adjusted comparisons between strata were performed for each outcome using a Cox proportional-hazards model. Where possible, the competing risk of death was accounted for. Multilevel mixed-effects ordered logistic regression was performed for AI grade at follow-up.

RESULTS

There were 295 patients of whom 52 had LV dilation. Operative outcomes were excellent; there were no significant differences between groups. Patients with LV dilation demonstrated significant improvement in iLVIDS overtime. There was no association between LV dilation and post-operative AI grade >2 (HR 0.88, 95% CI 0.21 to 3.67, p = 0.89) or odds of increased AI grade overtime (OR = 0.76, 95% CI 0.30 to 1.93, p = 0.57). There were no re-interventions among those with LV dilation. Adjusted mortality was significantly higher among those with LV dilation (HR 5.56, 95% CI 1.56 to 19.9), however, deaths were unrelated to aortic valve dilation.

CONCLUSIONS

Left ventricular dilation is not associated with poorer operative outcomes, post-operative AI, or re-intervention. It is associated with increased risk of mortality, though not from valvular dysfunction. LV dilation should not deter VSRR when otherwise indicated.

The Impact of Local vs. General Anesthesia in Patients Undergoing Thoracic Endovascular Aortic Surgery

OBJECTIVE

General anesthesia is associated with inherent risks that can be avoided by the use of lesser invasive anesthetic strategies. We hypothesize that examine and compare the use of local or regional anesthesia (LRA to general anesthesia (GA) in patients undergoing thoracic endovascular aortic repair (TEVAR).

METHODS

Patients undergoing TEVAR between 2010-2020 in the Vascular Quality Initiative were analyzed. Exclusion criteria included receipt of branched or physician modified endografts and devices extending distally beyond Zone 5. Patients were categorized as receiving LRA or GA. Center volume was reported by quartile according to annualized TEVAR volume and operative outcomes were compared using appropriate frequentists tests. Univariable and multivariable regression models for anesthesia type and operative outcomes were created to compare unadjusted and adjusted rates of each outcome. Long-term survival was estimated using a Kaplan-Meier survival estimator, while adjusted survival analysis was performed using a Cox proportional-hazards model.

RESULTS

Of the 17,099 patients who underwent TEVAR, 7,299 met the inclusion and exclusion criteria. Of these, 3.8% received LRA. There were no significant differences in the annual proportion of patients who received LRA from 2011 to 2020 (p = 0.49, Chi-square test for trend). Only 18.8% of patients who received LRA were treated at the highest quartile volume centers. Patients who received LRA were older and more comorbid compared to those who received GA. There were no differences in in-hospital mortality (OR = 0.79, 95% CI 0.42 to 1.38, p = 0.44) or composite of any complication (OR = 0.79, 95% CI 0.54 to 1.14, p = 0.22) between patients who received LRA compared to GA. This also applied to patients presenting with rupture. Receipt of LRA was associated with lower odds of post-operative congestive heart failure (OR = 0.19, 95% CI 0.01 to 0.89, p = 0.01) as well as decreased length of ICU (OR = 0.54, 95% CI 0.40 to 0.72, p < 0.01) and hospital length of stay (OR = 0.64, 95% CI 0.46 to 0.84, p < 0.01). LRA was not associated with decreased long-term survival compared to GA (HR 0.95, 95% CI 0.72 to 1.25, p = 0.72).

CONCLUSION

Despite a greater number of baseline comorbidities, patients undergoing TEVAR with LRA experienced shorter ICU and post-operative lengths of stay, with similar operative outcomes and long-term survival compared to patients who received GA.. Similar findings were found amongst the rupture cohort. LRA should be considered more frequently in select patients undergoing TEVAR.

Practice Patterns and Outcomes of Transcatheter Aortic Valve Replacement in the United States and Japan: A Report From Joint Data Harmonization Initiative of STS/ACC TVT and J-TVT

Background

The practice pattern and outcome of medical devices following their regulatory approval may differ by country. The aim of this study is to compare postapproval national clinical registry data on transcatheter aortic valve replacement between the United States and Japan on patient characteristics, periprocedural outcomes, and the variability of outcomes as a part of a partnership program (Harmonization‐by‐Doing) between the 2 countries.

Methods and Results

The patient‐level data were extracted from the US Society of Thoracic Surgeons /American College of Cardiology Transcatheter Valve Therapy (STS/ACC TVT) and the J‐TVT (Japanese Transcatheter Valvular Therapy) registry, respectively, to analyze transcatheter aortic valve replacement outcomes between 2013 and 2019. Data entry for these registries was mandated by the federal regulators, and the majority of variable definitions were harmonized to allow direct data comparison. A total of 244 722 transcatheter aortic valve replacements from 646 institutions in the United States and 26 673 transcatheter aortic valve replacements from 171 institutions in Japan were analyzed. Median volume per site was 65 (interquartile range, 45–97) in the United States and 28 (interquartile range, 19–41) in Japan. Overall, patients in J‐TVT were older (United States: mean‐age, 80.1±8.7 versus Japan: 84.4±5.2; P<0.001), were more frequently women (45.9% versus 68.1%; P<0.001), and had higher median Society of Thoracic Surgeons Predicted Risk of Mortality (5.27% versus 6.20%; P<0.001) than patients in the United States. Japan had lower unadjusted 30‐day mortality (1.3% versus 3.2%; P<0.001) and composite outcomes of death, stroke, and bleeding (17.5 versus 22.5%; P<0.001) but had higher conversion to open surgery (0.94% versus 0.56%; P<0.001).

Conclusions

This collaborative analysis between the United States and Japan demonstrated the feasibility of international comparison using the national registries coded under mutual variable definitions. Both countries obtained excellent outcomes, although the Japanese had lower 30‐day mortality and major morbidity. Harmonization‐by‐Doing is one of the key steps needed to build global‐level learning to improve patient outcomes.

Association of Volume and Outcomes in 234,556 Patients Undergoing Surgical Aortic Valve Replacement

BACKGROUND

The relationship between institutional volume and operative mortality following SAVR remains unclear.

METHODS

From 1/2013 to 6/2018, 234,556 patients underwent isolated SAVR (n=144,177) or SAVR+CABG (n=90,379) within the STS ACSD. The association between annualized SAVR volume [Group 1 (1-25 SAVR), Group 2 (26-50 SAVR), Group 3 (51-100 SAVR), and Group 4 (>100 SAVR)] and operative mortality and composite major morbidity/mortality was assessed. Random effects models were used to evaluate whether historic (2013-2015) SAVR volume or risk-adjusted outcomes explained future (2016-2018) risk-adjusted outcomes.

RESULTS

The annualized median number of SAVRs per site was 35 [IQR: 22-59, isolated AVR: 20, AVR+CABG: 13]. Among isolated SAVR cases, the mean operative mortality and composite morbidity/mortality were 1.5% and 9.7%, respectively, at the highest volume sites (Group 4); with significantly higher rates among progressively lower volume groups (p-trend<0.001). After adjustment, lower volume centers experienced increased odds of operative mortality [Group 1 vs. 4 (Ref): AOR (SAVR), 2.24 (1.91-2.64); AOR (SAVR+CABG), 1.96 (1.67-2.30)] and major morbidity/mortality [AOR (SAVR), 1.53 (1.39-1.69); AOR (SAVR+CABG), 1.46 (1.32-1.61)] compared to the highest volume institutions. Substantial variation in outcomes was observed across hospitals within each volume category and prior outcomes explained a greater proportion of hospital operative outcomes than prior volume.

CONCLUSIONS

Operative outcomes following SAVR±CABG is inversely associated with institutional procedure volumes; however, prior outcomes are more predictive than prior volume of future outcomes. Given excellent outcomes observed at many lower volume hospitals, procedural outcomes may be preferable to procedural volumes as a quality metric.

PROSE: Prospective Randomized Trial of the On-X Mechanical Prosthesis and the St Jude Medical Mechanical Prosthesis Evaluation : Part 1(Patient Dynamics): Preoperative demographics and preoperative and operative risk factors

OBJECTIVES

The PROSE trial purpose is to investigate whether the incidence of thromboembolic-related complications is reduced with a current generation mechanical prosthesis (On-X Life Technologies/CryoLife Inc.-On-X) compared with a previous generation mechanical prosthesis (St Jude Medical-SJM). The primary purpose of the initial report is to document the preoperative demographics, and the preoperative and operative risk factors by individual prosthesis and by Western and Developing populations.

METHODS

The PROSE study was conducted in 28 worldwide centres and incorporated 855 subjects randomized between 2003 and 2016. The study enrollment was discontinued on August 31, 2016. The preoperative demographics incorporated age, gender, functional class, etiology, prosthetic degeneration, primary rhythm, primary valve lesion, weight, height, BSA and BMI. The preoperative and operative evaluation incorporated 24 risk factors.

RESULTS

The total patient population (855) incorporated On-X population (462) and the St Jude Medical population (393). There was no significant difference of any of the preoperative demographics between the On-X and SJM groups. The preoperative and operative risk factors evaluation showed there was no significant difference between the On-X and St Jude Medical populations. The preoperative and operative risk factors by valve position (aortic and mitral) also documented no differentiation. The dominant preoperative demographics of the Western world population were older age, male gender, sinus rhythm, aortic stenosis, congenital aortic lesion, and mitral regurgitation. The dominant demographics of the Developing world population were rheumatic etiology, atrial fibrillation, aortic regurgitation, mixed aortic lesions, mitral stenosis and mixed mitral lesions. The Developing world group had only one significant risk factor, congestive heart failure. The majority of the preoperative and operative risk factors were significant in the Western world population.

CONCLUSIONS

The preoperative demographics do not differentiate the prostheses but do differentiate the Western and Developing world populations. The preoperative and operative risk factors do not differentiate the prostheses BUT do differentiate the Western and Developing world populations.

Socioeconomic and Geographic Characteristics of Hospitals Establishing Transcatheter Aortic Valve Replacement Programs, 2012-2018

BACKGROUND

Despite the benefits of novel therapeutics, inequitable diffusion of new technologies may generate disparities. We examined the growth of transcatheter aortic valve replacement (TAVR) in the United States to understand the characteristics of hospitals that developed TAVR programs and the socioeconomic status of patients these hospitals served.

METHODS

We identified fee-for-service Medicare beneficiaries aged 66 years or older who underwent TAVR between January 1, 2012, and December 31, 2018, and hospitals that developed TAVR programs (defined as performing ≥10 TAVRs over the study period). We used linear regression models to compare socioeconomic characteristics of patients treated at hospitals that did and did not establish TAVR programs and described the association between core-based statistical area level markers of socioeconomic status and TAVR rates.

RESULTS

Between 2012 and 2018, 583 hospitals developed new TAVR programs, including 572 (98.1%) in metropolitan areas, and 293 (50.3%) in metropolitan areas with preexisting TAVR programs. Compared with hospitals that did not start TAVR programs, hospitals that did start TAVR programs treated fewer patients with dual eligibility for Medicaid (difference of -2.83% [95% CI, -3.78% to -1.89%], P≤0.01), higher median household incomes (difference $2447 [95% CI, $1348-$3547], P=0.03), and from areas with lower distressed communities index scores (difference -4.02 units [95% CI, -5.43 to -2.61], P≤0.01). After adjusting for the age, clinical comorbidities, race and ethnicity and socioeconomic status, areas with TAVR programs had higher rates of TAVR and TAVR rates per 100 000 Medicare beneficiaries were higher in core-based statistical areas with fewer dual eligible patients, higher median income, and lower distressed communities index scores.

CONCLUSIONS

During the initial growth phase of TAVR programs in the United States, hospitals serving wealthier patients were more likely to start programs. This pattern of growth has led to inequities in the dispersion of TAVR, with lower rates in poorer communities.

National Outcomes of Elective Hybrid Arch Debranching with Endograft Exclusion versus Total Arch Replacement Procedures: Analysis of the Society of Thoracic Surgeons Adult Cardiac Surgery Database

OBJECTIVE

 Hybrid arch procedures (arch vessel debranching with thoracic endovascular aneurysm repair [TEVAR] coverage of arch pathology) have been presented as an alternative to total arch replacement (TAR). But multicenter-based analyses of these two procedures are needed to benchmark the field and establish areas of improvement.

METHODS

 The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database from July 2014 to December 2015 was queried for elective TAR and hybrid arch procedures. Demographics and operative characteristics were compared and stepwise variable selection was used to create a risk-set used for adjustment of all multivariable models.

RESULTS

 A total of 1,011 patients met inclusion criteria, 884 underwent TAR, and 127 had hybrid arch procedures. TAR patients were younger (mean age: 62.7 ± 13.3 vs. 66.7 ± 11.9 years; p = 0.001) and had less peripheral vascular disease (34.0 vs. 49.6%; p < 0.001) and preoperative dialysis (1.7 vs. 4.7%; p = 0.026), but similar history of stroke (p = 0.91)/cerebrovascular disease (p = 0.52). TAR patients had more concomitant procedures (60 vs. 34.6%; p < 0.0001). TAR patients had lower mortality (6.7 vs. 12.6%; p = 0.02), stroke (6.9 vs. 15%; p = 0.002), paralysis (1.8 vs. 7.1%; p = 0.002), renal failure (4.6 vs. 8.7%; p = 0.045), and STS morbidity (34.2 vs. 42.5%; p = 0.067). Composite mortality, stroke, and paralysis were significantly lower with TAR (11.5 vs. 25.2%; p = 0.0001). After risk adjustment, analysis showed hybrid arch procedures imparted an increased odds of mortality (odds ratio [OR] = 1.91, p = 0.046), stroke (OR = 2.3, p = 0.005), and composite endpoint of stroke or mortality (OR = 2.31, p = 0.0002).

CONCLUSION

 TAR remains the gold standard for elective aortic arch pathologies. Despite risk adjustment, hybrid arch procedures were associated with increased risk of mortality and stroke, advocating for careful adoption of these strategies.

Dynamic Volumetric Assessment of the Aortic Root: The Influence of Bicuspid Aortic Valve Competence

BACKGROUND

Aortic root evaluation is conventionally based on 2-dimensional measurements at a single phase of the cardiac cycle. This work presents an image analysis method for assessing dynamic 3-dimensional changes in the aortic root of minimally calcified bicuspid aortic valves (BAVs) with and without moderate to severe aortic regurgitation.

METHODS

The aortic root was segmented over the full cardiac cycle in 3-dimensional transesophageal echocardiographic images acquired from 19 patients with minimally calcified BAVs and from 16 patients with physiologically normal tricuspid aortic valves (TAVs). The size and dynamics of the aortic root were assessed using the following image-derived measurements: absolute mean root volume and mean area at the level of the ventriculoaortic junction, sinuses of Valsalva, and sinotubular junction, as well as normalized root volume change and normalized area change of the ventriculoaortic junction, sinuses of Valsalva, and sinotubular junction over the cardiac cycle.

RESULTS

Normalized volume change over the cardiac cycle was significantly greater in BAV roots with moderate to severe regurgitation than in normal TAV roots and in BAV roots with no or mild regurgitation. Aortic root dynamics were most significantly different at the mid-level of the sinuses of Valsalva in BAVs with moderate to severe regurgitation than in competent TAVs and BAVs.

CONCLUSIONS

Echocardiographic reconstruction of the aortic root demonstrates significant differences in dynamics of BAV roots with moderate to severe regurgitation relative to physiologically normal TAVs and competent BAVs. This finding may have implications for risk of future dilatation, dissection, or rupture, which warrant further investigation.

The impact of surgeon and hospital procedural volume on outcomes after aortic root replacement in the United States

OBJECTIVE

Surgeon procedural volume for complex cardiac procedures have become important quality metrics. The objective is to determine the association of surgeon and hospital case volume on patient outcomes after an aortic root replacement for aortic root aneurysms.

METHODS

From 2009 to 2014, 4629 Medicare patients underwent an aortic root replacement for a root aneurysm. Procedures were performed by 1276 surgeons at 718 hospitals. Patients with endocarditis, aortic rupture, or Type-A dissection were excluded. Procedural volume was defined as mean number of cases performed each year during the study period. The impact of hospital and surgeon volume on adjusted 30-day mortality was analyzed as a continuous variable using adjusted logistic regression with cubic splines.

RESULTS

After an aortic root replacement, we observed a nonlinear reduction in the adjusted odds ratio for 30-day mortality as surgeon and hospital volume increased. Surgeons that performed approximately five cases/year and hospitals that completed approximately five cases/year had the greatest reduction in the odds of perioperative death. Patients treated at high-volume hospitals (≥4.5 cases/year) had a lower risk for 30-day postoperative stroke (hazard ratio [HR] = 0.51, p = .008), myocardial infarction (HR = 0.49, p = .016), hemodialysis (HR = 0.44, p = .005), and reoperation (HR = 0.48, p = .003). Additionally, patients treated with high-volume surgeons (≥9 cases/year) had lower risk for stroke (HR = 0.65, p = .005), hemodialysis (HR = 0.65, p = .03), sepsis (HR = 0.62, p = .03), and reoperation (HR = 0.67, p = .004).

CONCLUSION

Among Medicare patients undergoing an aortic root replacement, there is a strong inverse relationship between annualized surgeon and hospital case volume and postoperative outcomes. Procedural volume is an important quality metric for this high-risk procedure.

Effect of Aortic Valve Type on Patients Who Undergo Type A Aortic Dissection Repair

Aortic valve replacement (AVR) is common in the setting of type A aortic dissection (TAAD) repair. Here, we evaluated the association between prosthesis choice and patient outcomes in an international patient cohort. We reviewed data from the International Registry of Acute Aortic Dissection (IRAD) interventional cohort to examine the relationship between valve choice and short- and mid-term patient outcomes. Between January 1996 and March 2016, 1290 surgically treated patients with TAAD were entered into the IRAD interventional cohort. Of those, 364 patients undergoing TAAD repair underwent aortic valve replacement (AVR; mean age, 57 years). The mechanical valve cohort consisted of 189 patients, of which 151 (79.9%) had a root replacement. The nonmechanical valve cohort consisted of 5 patients who received homografts and 160 patients who received a biologic AVR, with a total of 118 (71.5%) patients who underwent root replacements. The mean follow-up time was 2.92 ± 1.75 years overall (2.46 ± 1.69 years for the mechanical valve cohort and 3.48 ± 1.8 years for the nonmechanical valve cohort). After propensity matching, Kaplan-Meier estimates of 4-year survival rates after surgery were 64.8% in the mechanical valve group compared with 74.7% in the nonmechanical valve group (p = 0.921). A stratified Cox model for 4-year mortality showed no difference in hazard between valve types after adjusting for the propensity score (p = 0.854). A biologic valve is a reasonable option in patients with TAAD who require AVR. Although this option avoids the potential risks of anticoagulation, long-term follow up is necessary to assess the effect of reoperations or transcatheter interventions for structural valve degeneration.

Composite Metric for Benchmarking Site Performance in Transcatheter Aortic Valve Replacement: Results From the STS/ACC TVT Registry

BACKGROUND

Transcatheter aortic valve replacement (TAVR) is a transformative therapy for aortic stenosis. Despite rapid improvements in technology and techniques, serious complications remain relatively common and are not well described by single outcome measures. The purpose of this study was to determine whether there is site-level variation in TAVR outcomes in the United States using a novel 30-day composite measure.

METHODS

We performed a retrospective cohort study using data from the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapies Registry to develop a novel ranked composite performance measure that incorporates mortality and serious complications. The selection and rank order of the complications for the composite was determined by their adjusted association with 1-year outcomes. Sites with risk-adjusted outcomes significantly more or less frequent than the national average based on a 95% probability interval were classified as performing worse or better than expected.

RESULTS

The development cohort consisted of 52 561 patients who underwent TAVR between January 1, 2015, and December 31, 2017. Based on associations with 1-year risk-adjusted mortality and health status, we identified 4 periprocedural complications to include in the composite risk model in addition to mortality. Ranked empirically according to severity, these included stroke, major, life-threatening or disabling bleeding, stage III acute kidney injury, and moderate or severe perivalvular regurgitation. Based on these ranked outcomes, we found that there was significant site-level variation in quality of care in TAVR in the United States. Overall, better than expected site performance was observed in 25/301 (8%) sites, performance as expected was observed in 242/301 sites (80%), and worse than expected performance was observed in 34/301 (11%) sites. Thirty-day mortality; stroke; major, life-threatening, or disabling bleeding; and moderate or severe perivalvular leak were each substantially more common in sites with worse than expected performance as compared with other sites. There was good aggregate reliability of the model.

CONCLUSIONS

There are substantial variations in the quality of TAVR care received in the United States and 11% of sites were identified as providing care below the average level of performance. Further study is necessary to determine structural, process-related, and technical factors associated with high- and low-performing sites.

Evaluation of the Gore TAG thoracic branch endoprosthesis in the treatment of proximal descending thoracic aortic aneurysms

BACKGROUND

Thoracic endovascular aortic repair has radically transformed the treatment of descending thoracic aortic aneurysms. However, when aneurysms involve the aortic arch in the region of the left subclavian artery, branch vessel preservation must be considered. Branched aortic endografts have provided a new option to maintain branch patency.

METHODS

Six investigative sites enrolled 31 patients in a nonrandomized, prospective investigational device exemption feasibility trial of a single branched aortic endograft for the management of aneurysms that include the distal aortic arch. The Gore TAG thoracic branch endoprosthesis (W. L. Gore & Associates, Inc, Flagstaff, Ariz), an investigational device, allows for graft placement proximal to the left subclavian artery and incorporates a single side branch for left subclavian perfusion.

RESULTS

All 31 patients (100%) had undergone successful implantation of the investigational device in landing zone 2. Men slightly outnumbered women (51.6%). Their average age was 74.1 ± 10.4 years. The aneurysm morphology was fusiform in 12 and saccular in 19 patients, with a mean maximum aortic diameter of 54.8 ± 10.9 mm. The mean follow-up period for the cohort was 25.2 ± 11.1 months. We have reported the patient outcomes at 1 month and 1 year. At 1 month, the side branch patency was 100% and the freedom from core laboratory-reported device-related endoleak (types I and III) was 96.7%, without 30-day death or permanent paraplegia. One patient experienced a procedure-related stroke. Through 1 year, five patients had died; none of the deaths were related to the device or procedure (clinical endpoint committee adjudicated). One thoracic reintervention was required. No conversions were required, and no aneurysm growth (core laboratory) was reported. One case of the loss of side branch patency was diagnosed in the left subclavian artery in an asymptomatic individual from computed tomography at 6 months, with no reported subsequent adverse events due to loss of patency. Endoleaks were reported by the core laboratory in five patients at 12 months (two, type II; and three, indeterminate).

CONCLUSIONS

The present investigational device exemption feasibility study has reported the preliminary results of the use of a single side branch endograft to treat patients with proximal descending thoracic aortic aneurysms.