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.

Incidence, Management, and Associated Clinical Outcomes of New-Onset Atrial Fibrillation Following Transcatheter Aortic Valve Replacement: An Analysis From the STS/ACC TVT Registry.

OBJECTIVES: The aim of this study was to evaluate incidence, care patterns, and clinical outcomes in patients developing new-onset atrial fibrillation (AF) following transcatheter aortic valve replacement (TAVR). BACKGROUND: Pre-procedural AF has been associated with adverse outcomes in patients undergoing TAVR, but the incidence of new-onset AF, associated anticoagulant management, and subsequent clinical outcomes are unclear. METHODS: Using the Society of Thoracic Surgeons/American College of Cardiology TVT (Transcatheter Valve Therapy) Registry linked with Medicare claims, patients undergoing TAVR from 2011 to 2015 who developed post-procedural AF were evaluated. Patients with known AF prior to TAVR were excluded. Outcomes of interest included in-hospital mortality and stroke and all-cause mortality, stroke, and bleeding at 12 months. Multivariate adjustment was then performed to determine differences in 1-year outcomes among those with and without new post-procedural AF, stratified by anticoagulation status. RESULTS: We identified 1,138 of 13,556 patients (8.4%) who developed new onset AF (4.4% of transfemoral [TF]-access patients, 16.5% of non-TF-access patients). Patients developing AF were older, more likely female, had higher Society of Thoracic Surgeons risk scores, and were often treated using non-TF access. Despite having a median CHA2DS2-VASc score of 5 (25th and 75th percentile: 5 to 6), only 28.9% of patients with new AF were discharged on oral anticoagulation. In-hospital mortality (7.8% vs. 3.4%; p < 0.01) and stroke (4.7% vs. 2.0%; p < 0.01) were higher among patients who developed post-procedural AF compared with those who did not. At 1 year, rates of death (adjusted hazard ratio [HR]: 1.37; 95% confidence interval [CI]: 1.19 to 1.59), stroke (adjusted HR: 1.50; 95% CI: 1.14 to 1.98), and bleeding (adjusted HR: 1.24; 95% CI: 1.10 to 1.40) were higher among patients with new-onset AF. One-year mortality rates were highest among patients who developed new-onset AF but were not discharged on anticoagulation. CONCLUSIONS: Post-TAVR AF occurred in 8.4% of patients (4.4% with TF access, 16.5% with non-TF access), with fewer than one-third of patients receiving anticoagulation at discharge, and was associated with increased risk for in-hospital and 1-year mortality and stroke. Given the clinical significance of post-TAVR AF, additional studies are necessary to delineate the optimal management strategy in this high-risk population.

Stroke and Cardiovascular Outcomes in Patients With Carotid Disease Undergoing Transcatheter Aortic Valve Replacement.

BACKGROUND: Stroke is a serious complication of both transcatheter aortic valve replacement (TAVR) and carotid artery disease (CD). The implications of CD in patients undergoing TAVR are unclear. METHODS AND RESULTS: The Society of Thoracic Surgeons and American College of Cardiology Transcatheter Valve Therapies Registry, consisting of data from consecutive US TAVR cases during the years 2013 to 2015, was linked to Medicare claims data to ascertain 30-day and 1-year cumulative incidence rates of stroke and all-cause mortality. We compared 30-day and 1-year stroke and mortality outcomes between patients with no-CD and patients with moderate, severe, and occlusive CD and adjusted for baseline covariates using proportional hazards models. Among 29 143 patients undergoing TAVR across 390 US sites, 22% had CD. Patients with CD had higher rates of prior hypertension, diabetes mellitus, stroke, and myocardial infarction. Observed in-hospital stroke rates were 2.0% among no-CD, 2.5% among moderate CD, 3.0% among severe CD, and 2.6% among occlusive CD. There was no association between the presence of CD and 30-day stroke (adjusted hazard ratio, 1.16; 95% confidence interval, 0.94-1.43) or mortality (adjusted hazard ratio, 1.10; 95% confidence interval, 0.95-1.28). There was no association between CD and 1-year stroke (adjusted hazard ratio, 1.03; 95% confidence interval, 0.86-1.24) or mortality (adjusted hazard ratio, 1.02; 95% confidence interval, 0.93-1.12). Furthermore, there was no significant risk-adjusted association between severity of CD and 30-day or 1-year stroke or mortality. CONCLUSIONS: CD is common among TAVR patients, present in 1 of 5. CD was not associated with an increased risk of stroke or mortality at 30 day or 1 year. Post-TAVR stroke seems to be because of mechanisms other than CD.

Assessment of single-bolus contrast administration technique using hybrid dual-source ECG-gated thoracic and dual-source non-ECG-gated high-pitch abdominopelvic CT acquisitions for procedural planning before transcatheter aortic valve replacement.

PURPOSE: This study aimed to assess vascular contrast opacification and homogeneity using single-bolus contrast administration with hybrid thoracic and abdominopelvic computed tomographic angiography in patients with severe aortic valve stenosis. MATERIALS AND METHODS: Combination electrocardiogram-gated thoracic and dual-source, high-pitch abdominopelvic computed tomographic angiography examinations of 50 patients with severe aortic stenosis between December 2013 and March 2014 were reviewed. Contrast administration was individualized to patient-specific physiology. Image analysis of vascular opacification was obtained and interdependencies of vascular contrast and homogeneity of contrast distribution were assessed. RESULTS: The mean volume of contrast administered was 106 ± 11.7 mL. Mean attenuation was 371 ± 90.7 Hounsfield units (HU) in the thoracic aorta and 388 ± 95.9 HU in the abdominal aorta. Homogeneous opacification was obtained throughout with coefficient of variation of 11%. CONCLUSIONS: Procedural planning for transcatheter aortic valve replacement can be achieved using a single-injection bolus contrast protocol in combination with a 2-part multidetector computed tomographic image acquisition technique with optimal opacification of major arterial structures.

Insurance status predicts acuity of thoracic aortic operations.

OBJECTIVE: Nonelective case status is the strongest predictor of mortality for thoracic aortic operations. We hypothesized that underinsured patients were more likely to require nonelective thoracic aortic surgery because of reduced access to preventative cardiovascular care and elective surgical services. METHODS: Between June 2005 and August 2011, 826 patients were admitted to a single aortic referral center and underwent 1 or more thoracic aortic operations. Patients with private insurance or Medicare (insured group, n=736; 89%) were compared with those with Medicaid or no insurance (underinsured group, n=90; 11%). RESULTS: The proportion of patients requiring nonelective surgery was higher for underinsured than insured patients (56% vs 26%, P<.0001). Multivariable analysis revealed underinsurance to be the strongest independent predictor of nonelective case status (odds ratio [OR], 2.67; P<.0001). Preoperative use of lipid-lowering medications (OR, 0.63; P<.009) or a history of aortic surgery (OR, 0.48; P<.001) was associated with a decreased risk of nonelective operation. However, after adjustment for differences in preoperative characteristics and case status, underinsurance did not confer an increased risk of procedural morbidity or mortality (adjusted OR, 0.94; P=.83) or late death (adjusted hazard ratio, 0.83, P=.58) when compared with insured patients. CONCLUSIONS: Underinsured patients were at the greatest risk of requiring nonelective thoracic aortic operation, possibly because of decreased use of lipid-lowering therapies and aortic surveillance. These data imply that greater access to preventative cardiovascular care may reduce the need for nonelective thoracic aortic surgery and lead to improved survival from thoracic aortic disease.

Insurance status is associated with acuity of presentation and outcomes for thoracic aortic operations.

BACKGROUND: Nonelective procedure status is the greatest risk factor for postoperative morbidity and mortality in patients undergoing thoracic aortic operations. We hypothesized that uninsured patients were more likely to require nonelective thoracic aortic operation due to decreased access to preventative care and elective surgical services. METHODS AND RESULTS: An observational study of the Society of Thoracic Surgeons Database identified 51 282 patients who underwent thoracic aortic surgery between 2007 and 2011 at 940 North American centers. Patients were stratified by insurance status (private insurance, Medicare, Medicaid, other insurance, or uninsured) as well as age <65 or ≥65 years to account for differences in Medicare eligibility. The need for nonelective thoracic aortic operation was highest for uninsured patients (71.7%) and lowest for privately insured patients (36.6%). The adjusted risks of nonelective operation were increased for uninsured patients (adjusted risk ratio, 1.77; 95% confidence interval, 1.70-1.83 for age <65 years; adjusted risk ratio, 1.46; 95% confidence interval, 1.29-1.62 for age ≥65 years) as well as Medicaid patients aged <65 years (adjusted risk ratio, 1.18; 95% confidence interval, 1.10-1.26) when compared with patients with private insurance. The adjusted risks of major morbidity or mortality were further increased for all patients aged <65 years without private insurance (adjusted risk ratios between 1.13 and 1.27). CONCLUSIONS: Insurance status was associated with acuity of presentation and major morbidity and mortality for thoracic aortic operations. Efforts to reduce insurance-based disparities in the care of patients with thoracic aortic disease seem warranted and may reduce the incidence of aortic emergencies and improve outcomes after thoracic aortic surgery.

Effects of institutional volumes on operative outcomes for aortic root replacement in North America.

OBJECTIVES: Hospital procedure volume has been strongly associated with postoperative mortality for a number of complex cardiovascular procedures. Although not yet described, a similar relationship might be expected for surgical procedures involving the aortic root and/or ascending aorta. The present study sought to evaluate the relationship between the volume of aortic root replacement procedures and the operative results for centers in North America. METHODS: Patient-level data for 13,358 elective aortic root and aortic valve-ascending aortic procedures performed from 2004 through 2007 were obtained from 741 North American hospitals participating in the Society of Thoracic Surgeons Adult Cardiac Surgery Database. Marginal logistic regression modeling was used for risk adjustment. The hospital procedure volume was the primary predictor variable. Patient demographics, comorbid conditions, and operative characteristics were included as the predictor variables for risk adjustment. The primary outcome measures included unadjusted operative mortality and adjusted odds ratio for mortality. RESULTS: The preoperative patient risk profiles were similar at all center volume levels, and the overall unadjusted operative mortality was 4.5%. The unadjusted operative mortality increased with decreasing case volume, from 3.4% in the highest volume centers to 5.8% in the lowest volume centers. Whether hospital volume was assessed as a categorical or continuous variable, its relationship with the adjusted odds ratio for mortality was nonlinear. A negative association was seen between the hospital procedural volume and adjusted odds ratio for mortality (P < .001) that was most pronounced among hospitals performing fewer than 30 to 40 procedures annually. CONCLUSIONS: Patients undergoing elective aortic root or combined aortic valve-ascending aortic surgery at North American hospitals that performed fewer than 30 to 40 of such procedures annually have greater risk-adjusted mortality than those undergoing surgery in higher volume hospitals. Causative factors for this inverse association between hospital volume and mortality deserve additional analysis.

Risk-adjusted survival after tissue versus mechanical aortic valve replacement: a 23-year assessment.

BACKGROUND AND AIM OF THE STUDY: Detailed analyses of risk-adjusted outcomes after mitral valve surgery have documented significant survival decrements with tissue valves at any age. Several recent studies of prosthetic aortic valve replacement (AVR) also have suggested a poorer performance of tissue valves, although analyses have been limited to small matched series. The study aim was to test the hypothesis that AVR with tissue valves is associated with a lower risk-adjusted survival, as compared to mechanical valves. METHODS: Between 1986 and 2009, primary isolated AVR, with or without coronary artery bypass grafting (CABG), was performed with currently available valve types in 2148 patients (1108 tissue valves, 1040 mechanical). Patients were selected for tissue valves to be used primarily in the elderly. Baseline and operative characteristics were documented prospectively with a consistent variable set over the entire 23-year period. Follow up was obtained with mailed questionnaires, supplemented by National Death Index searches. The average time to death or follow up was seven years, and follow up for survival was 96.2% complete. Risk-adjusted survival characteristics for the two groups were evaluated using a Cox proportional hazards model with stepwise selection of candidate variables. RESULTS: Differences in baseline characteristics between groups were (tissue versus mechanical): median age 73 versus 61 years; non-elective surgery 32% versus 28%; CABG 45% versus 35%; median ejection fraction 55% versus 55%; renal failure 6% versus 1%; diabetes 18% versus 7% (p<0.01). Unadjusted Kaplan-Meier survival was significantly lower with tissue than mechanical valves; however, after risk adjustment for the adverse profiles of tissue valve patients, no significant difference was observed in survival after tissue or mechanical AVR. Thus, the hypothesis did not hold, and risk-adjusted survival was equivalent, of course qualified by the fact that selection bias was evident. CONCLUSION: With selection criteria that employed tissue AVR more frequently in elderly patients, tissue and mechanical valves achieved similar survival characteristics across the spectrum of patient risk. Further studies of the relative outcomes of mechanical versus tissue valves across the spectrum of patient age seem indicated.

Intraoperative use of low-dose recombinant activated factor VII during thoracic aortic operations.

BACKGROUND: Numerous studies have supported the effectiveness of recombinant activated factor VII (rFVIIa) for the control of bleeding after cardiac procedures; however safety concerns persist. Here we report the novel use of intraoperative low-dose rFVIIa in thoracic aortic operations, a strategy intended to improve safety by minimizing rFVIIa exposure. METHODS: Between July 2005 and December 2010, 425 consecutive patients at a single referral center underwent thoracic aortic operations with cardiopulmonary bypass (CPB); 77 of these patients received intraoperative low-dose rFVIIa (≤60 µg/kg) for severe coagulopathy after CPB. Propensity matching produced a cohort of 88 patients (44 received intraoperative low-dose rFVIIa and 44 controls) for comparison. RESULTS: Matched patients receiving intraoperative low-dose rFVIIa got an initial median dose of 32 µg/kg (interquartile range [IQR], 16-43 µg/kg) rFVIIa given 51 minutes (42-67 minutes) after separation from CPB. Patients receiving intraoperative low-dose rFVIIa demonstrated improved postoperative coagulation measurements (partial thromboplastin time 28.6 versus 31.5 seconds; p=0.05; international normalized ratio, 0.8 versus 1.2; p<0.0001) and received 50% fewer postoperative blood product transfusions (2.5 versus 5.0 units; p=0.05) compared with control patients. No patient receiving intraoperative low-dose rFVIIa required postoperative rFVIIa administration or reexploration for bleeding. Rates of stroke, thromboembolism, myocardial infarction, and other adverse events were equivalent between groups. CONCLUSIONS: Intraoperative low-dose rFVIIa led to improved postoperative hemostasis with no apparent increase in adverse events. Intraoperative rFVIIa administration in appropriately selected patients may correct coagulopathy early in the course of refractory blood loss and lead to improved safety through the use of smaller rFVIIa doses. Appropriately powered randomized studies are necessary to confirm the safety and efficacy of this approach.

Outcomes for endocarditis surgery in North America: a simplified risk scoring system.

OBJECTIVE: Operation for infective endocarditis is associated with the highest mortality of any valve disease, with overall rates of in-hospital mortality exceeding 20%. The Society of Thoracic Surgeons Adult Cardiac Surgery Database was examined to develop a simple risk scoring system and identify areas for quality improvement. METHODS: From 2002 through 2008, 19,543 operations were performed for infective endocarditis. Logistic regression analysis related baseline characteristics to both operative mortality and a composite of mortality and major morbidity within 30 days. Points were assigned to each risk factor, and estimated risk was obtained by averaging events for all patients having the same number of points. RESULTS: Overall unadjusted mortality was 8.2%, and complications occurred in 53%. Significant preoperative risk factors for mortality (associated points) were as follows: emergency, salvage status, or cardiogenic shock (17), preoperative hemodialysis, renal failure, or creatinine level less than 2.0 (12), preoperative inotropic or balloon pump support (10), active (vs treated) endocarditis (10), multiple valve involvement (9), insulin-dependent diabetes (8), arrhythmia (8), previous cardiac surgery (7), urgent status without cardiogenic shock (6), non-insulin-dependent diabetes (6), hypertension (5), and chronic lung disease (5), with a C statistic of 0.7578 (all P < .001). Risk-adjusted mortality and major morbidity were unchanged over the course of the study. In the entire data set, mortality was better if "any valve" was repaired (odds ratio = 0.76; P = .0023). CONCLUSIONS: Operative mortality for surgically treated infective endocarditis is substantially lower than reported in-hospital mortality rates for infective endocarditis. The described risk scoring system will inform clinical decision-making in these complex patients.