Transcatheter tricuspid valve replacement in dehisced flexible ring.

Transcatheter tricuspid valve-in-surgical annuloplasty ring is an appealing concept in light of the high mortality associated with reoperation on the tricuspid valve. The clinical necessity of this procedure is derived from a considerable failure rate of tricuspid repairs over time. The presented case demonstrates that transcatheter valve-in-ring is a feasible option for patients with flexible tricuspid ring even in the context of significant ring dehiscence. Meticulous procedural planning, preemptively addressing a potential paravalvular leak, and clear understanding of the intricate three-dimensional anatomy are imperative for procedural success.

Conscious Sedation Versus General Anesthesia for Transcatheter Aortic Valve Replacement: Insights from the National Cardiovascular Data Registry Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry.

BACKGROUND: Conscious sedation is used during transcatheter aortic valve replacement (TAVR) with limited evidence as to the safety and efficacy of this practice. METHODS: The National Cardiovascular Data Registry Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry was used to characterize the anesthesia choice and clinical outcomes of all US patients undergoing elective percutaneous transfemoral TAVR between April 1, 2014, and June 30, 2015. Raw and inverse probability of treatment-weighted analyses were performed to compare patients undergoing TAVR with general anesthesia with patients undergoing TAVR with conscious sedation on an intention-to-treat basis for the primary outcome of in-hospital mortality, and secondary outcomes including 30-day mortality, in-hospital and 30-day death/stroke, procedural success, intensive care unit and hospital length-of-stay, and rates of discharge to home. Post hoc falsification end point analyses were performed to evaluate for residual confounding. RESULTS: Conscious sedation was used in 1737/10 997 (15.8%) cases with a significant trend of increasing usage over the time period studied (P for trend<0.001). In raw analyses, intraprocedural success with conscious sedation and general anesthesia was similar (98.2% versus 98.5%, P=0.31). The conscious sedation group was less likely to experience in-hospital (1.6% versus 2.5%, P=0.03) and 30-day death (2.9% versus 4.1%, P=0.03). Conversion from conscious sedation to general anesthesia was noted in 102 of 1737 (5.9%) of conscious sedation cases. After inverse probability of treatment-weighted adjustment for 51 covariates, conscious sedation was associated with lower procedural success (97.9% versus 98.6%, P<0.001) and a reduced rate of mortality at the in-hospital (1.5% versus 2.4%, P<0.001) and 30-day (2.3% versus 4.0%, P<0.001) time points. Conscious sedation was associated with reductions in procedural inotrope requirement, intensive care unit and hospital length of stay (6.0 versus 6.5 days, P<0.001), and combined 30-day death/stroke rates (4.8% versus 6.4%, P<0.001). Falsification end point analyses of vascular complications, bleeding, and new pacemaker/defibrillator implantation demonstrated no significant differences between groups after adjustment. CONCLUSIONS: In US practice, conscious sedation is associated with briefer length of stay and lower in-hospital and 30-day mortality in comparison with TAVR with general anesthesia in both unadjusted and adjusted analyses. These results suggest the safety of conscious sedation in this population, although comparative effectiveness analyses using observational data cannot definitively establish the superiority of one technique over another.

Veno-Venous Extracorporeal Life Support in Hemodynamically Unstable Patients With ARDS.

When clinicians consider extracorporeal life support (ECLS) for acute respiratory distress syndrome (ARDS) patients with hemodynamic instability, both veno-arterial (VA) and veno-venous (VV) ECLS are therapeutic possibilities. We analyzed 17 patients with ARDS on inotropic or vasopressor support requiring ECLS for refractory hypoxemia. After implementing VV ECLS, pressor requirements (based on norepinephrine equivalents) were significantly lower in all patients (P = .0001 for overall comparison across time points). None of the 17 patients required conversion from VV ECLS to VA ECLS (95% confidence interval 0%-20.0%). In this sample of 17 patients with substantial baseline vasopressor support and hypoxemic respiratory failure, initiation of VV ECLS was associated with reduced pressor requirements. Such a strategy may help avoid complications of VA ECLS in patients with both respiratory and hemodynamic failure.

Natural Infections With Pigeon Paramyxovirus Serotype 1: Pathologic Changes in Eurasian Collared-Doves ( Streptopelia decaocto) and Rock Pigeons ( Columba livia) in the United States.

Pigeon paramyxovirus serotype 1 (PPMV-1) is a globally distributed, virulent member of the avian paramyxovirus serotype 1 serogroup that causes mortality in columbiformes and poultry. Following introduction into the United States in the mid-1980s, PPMV-1 rapidly spread causing numerous mortality events in Eurasian collared-doves ( Streptopelia decaocto) (ECDOs) and rock pigeons ( Columba livia) (ROPIs). The investigators reviewed pathological findings of 70 naturally infected, free-ranging columbiforms from 25 different mortality events in the United States. Immunohistochemistry targeting PPMV-1 nucleoprotein was used to determine the tissue distribution of the virus in a subset of 17 birds from 10 of the studied outbreaks. ECDOs (61 birds) and ROPIs (9 birds) were the only species in which PPMV-1-associated disease was confirmed by viral isolation and presence of histologic lesions. Acute to subacute tubulointerstitial nephritis and necrotizing pancreatitis were the most frequent histologic lesions, with immunolabeling of viral antigen in renal tubular epithelial cells and pancreatic acinar epithelium. Lymphoid depletion of bursa of Fabricius and spleen was common, but the presence of viral antigen in these organs was inconsistent among infected birds. Hepatocellular necrosis was occasionally present with immunolabeling of hypertrophic Kupffer cells, and immunopositive eosinophilic intracytoplasmic inclusion bodies were present in hepatocytes of 1 ECDO. Immunopositive lymphocytic choroiditis was present in 1 ECDO, while lymphocytic meningoencephalitis was frequent in ROPIs in absence of immunolabeling. This study demonstrates widespread presence of PPMV-1 antigen in association with histologic lesions, confirming the lethal potential of this virus in these particular bird species.

Variation in use of echocardiography among veterans who use the Veterans Health Administration vs Medicare.

BACKGROUND: Rapid growth in the provision of cardiac imaging tests has led to concerns about overuse. Little is known about the degree to which health care delivery system characteristics influence use and variation in echocardiography. METHODS: We analyzed administrative claims of veterans with heart failure older than 65 years from 2007 to 2010 across 34 metropolitan service areas (MSAs). We compared overall rates and geographic variation in use of transthoracic echocardiography (TTE) between veterans who used the Veterans Health Administration (VA) and propensity-matched veterans who used Medicare. "Dual users" were excluded. RESULTS: There were no significant differences in clinical characteristics or mortality between the propensity-matched cohorts (overall n = 30,404 veterans, mean age 76 years, mortality rate 52%). The Medicare cohort had a significantly higher overall rate of TTE use compared with the VA cohort (1.25 vs 0.38 TTEs per person-year, incidence rate ratio 2.89 [95% CI 2.80-3.00], both P < .001), but a similar coefficient of variation across MSAs (0.36 [95% CI 0.27-0.45] vs 0.48 [95% CI 0.37-0.59]). There was a moderate to strong correlation in variation at the MSA level between cohorts (Spearman r = 0.58, P < .001). CONCLUSION: Overall rates of TTE use were significantly higher in a Medicare cohort compared with a propensity score-matched VA cohort of veterans with heart failure living in urban areas, with similar relative degrees of geographic variation and moderate to strong regional correlation. Rates of TTE use may be strongly influenced by health care system characteristics, but local practice styles influence echocardiography rates irrespective of health system.

Efficacy of chemotherapy after progression during or following PARPi exposure in ovarian cancer.

BACKGROUND: Poly(ADP-ribose) polymerase inhibitors (PARPis) improved advanced ovarian cancer treatment. Most patients progress during or following PARPi exposure, however, with concerns about sensitivity of subsequent chemotherapy. PATIENTS AND METHODS: In this international cohort study, we evaluated the efficacy of a subsequent chemotherapy following PARPi exposure in high-grade ovarian carcinoma patients. Endpoints included progression-free survival (PFS), overall survival and a multivariable Cox model was built to identify factors influencing PFS. RESULTS: We included 291 patients from four international centers treated between January 2002 and December 2021. The median number of previous chemotherapy was 1 (1.0-7.0), the median duration of PARPi exposure was 6.5 months (0.2-54.3 months). PARPi was used in first line in 14.1% patients. Most progressions occurred under PARPi exposure (89.1%). A BRCA pathogenic variant was identified in 130 patients (44.7%), absent in 157 patients (54.0%), and undocumented in 4 patients (1.4%). Platinum-based CT (PBC) and non-PBC were administered as subsequent treatments in, respectively, 182 patients (62.5%) and 109 patients (37.5%). Multivariable analyses showed that platinum-free interval (PFI) >6 months [adjusted hazards ratio (HR), 0.52; 95% confidence interval (CI) 0.39-0.70] and type of initial surgery (adjusted HR, 1.41; 95% CI 1.07-1.87; interval or closing surgery versus primary surgery) were associated with PFS, independent of BRCA status or line of therapy (≥2 versus 1). In patients with a PFI >6 months, PBC was numerically associated with the best PFS (adjusted HR, 0.68; 95% CI 0.46-1.01). CONCLUSION: This is the largest real-world study assessing the efficacy of subsequent chemotherapy in patients progressing during PARPi exposure. The patients have poor outcomes. PBC is the best option in patients progressing on PARPi and eligible for PBC rechallenge (PFI >6 months).

Plasma and rectal mucosal oxylipin levels during aspirin and eicosapentaenoic acid treatment in the seAFOod polyp prevention trial.

BACKGROUND: Aspirin and eicosapentaenoic acid (EPA) have colorectal polyp prevention activity, alone and in combination. This study measured levels of plasma and rectal mucosal oxylipins in participants of the seAFOod 2 × 2 factorial, randomised, placebo-controlled trial, who received aspirin 300 mg daily and EPA 2000 mg free fatty acid, alone and in combination, for 12 months. METHODS: Resolvin (Rv) E1, 15-epi-lipoxin (LX) A4 and respective precursors 18-HEPE and 15-HETE (with chiral separation) were measured by ultra-high performance liquid chromatography-tandem mass spectrometry in plasma taken at baseline, 6 months and 12 months, as well as rectal mucosa obtained at trial exit colonoscopy at 12 months, in 401 trial participants. RESULTS: Despite detection of S- and R- enantiomers of 18-HEPE and 15-HETE in ng/ml concentrations, RvE1 or 15­epi-LXA4 were not detected above a limit of detection of 20 pg/ml in plasma or rectal mucosa, even in individuals randomised to both aspirin and EPA. We have confirmed in a large clinical trial cohort that prolonged (12 months) treatment with EPA is associated with increased plasma 18-HEPE concentrations (median [inter-quartile range] total 18-HEPE 0.51 [0.21-1.95] ng/ml at baseline versus 0.95 [0.46-4.06] ng/ml at 6 months [P<0.0001] in those randomised to EPA alone), which correlate strongly with respective rectal mucosal 18-HEPE levels (r = 0.82; P<0.001), but which do not predict polyp prevention efficacy by EPA or aspirin. CONCLUSION: Analysis of seAFOod trial plasma and rectal mucosal samples has not provided evidence of synthesis of the EPA-derived specialised pro-resolving mediator RvE1 or aspirin-trigged lipoxin 15­epi-LXA4. We cannot rule out degradation of individual oxylipins during sample collection and storage but readily measurable precursor oxylipins argues against widespread degradation.

Valve-sparing root reimplantation with a Valsalva graft for a trileaflet aortic valve.

Valve-sparing root reimplantation has become an attractive alternative to conventional aortic root replacement in young patients as a means to avoid the anticoagulation required for mechanical roots while improving the durability compared to bioprosthetic valved conduits. In this video tutorial, we present our step-by-step process for performing a valve-sparing root reimplantation with a Valsalva graft for a patient with an aortic root aneurysm and a trileaflet aortic valve.

Neighborhood socioeconomic status is associated with differences in operative management and long-term survival after coronary artery bypass grafting.

OBJECTIVE: We sought to characterize differences in operative management and surgical outcomes after coronary artery bypass grafting associated with the socioeconomic context in which a patient lives. METHODS: We used a validated index of 17 variables derived from the US Census Bureau to assign socioeconomic status at the block group level to patients who underwent isolated coronary artery bypass grafting at a single institution over a 16-year period. Operative mortality, stroke, renal failure, prolonged ventilation, sternal wound infection, reoperation, composite morbidity or mortality, long-term survival, and use of arterial conduits were the outcomes assessed. RESULTS: This study was composed of 6751 patients. Lower socioeconomic status was significantly associated with increased rates of stroke, renal failure, prolonged ventilation, and composite morbidity or mortality in a multivariable analysis. Low socioeconomic status was significantly associated with poorer long-term adjusted survival (hazard ratio, 1.26; 95% confidence interval, 1.03-1.55). Finally, lower socioeconomic status was significantly associated with decreased use of more than 1 arterial conduits in a multivariable analysis. CONCLUSIONS: The socioeconomic context in which a patient lives is significantly associated with short- and long-term outcomes after coronary artery bypass grafting. There may also be variation in operative management, demonstrated by decreased use of arterial conduits. Lower rates of arterial revascularization among socioeconomically disadvantaged patients who undergo coronary artery revascularization may provide a target for intervention.

Self-Expanding Valve System for Treatment of Native Aortic Regurgitation by Transcatheter Aortic Valve Implantation (from the STS/ACC TVT Registry).

Transcatheter aortic valve implantation (TAVI) is approved for treatment of symptomatic aortic stenosis in patients at increased risk for surgical valve replacement, but outcomes data in patients with severe native aortic regurgitation (AR) treated with TAVI remain limited. The objective of this analysis was to evaluate outcomes among patients identified in the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapies Registry who underwent TAVI for native AR with a commercially available self-expanding valve system. From January 2014 to December 2017, 230 patients in the TVT Registry underwent TAVI for primary severe native AR using a commercially available self-expanding valve (n = 81, CoreValve; n = 149, Evolut R). For inclusion, AR was either pure or mixed with predominantly moderate/severe AR and mean aortic valve gradient ≤20 mm Hg. Thirty-day outcomes were evaluated using time-to-event methods. Device success was reported in 81.7% of patients (CoreValve, 72.2%; Evolut R, 86.9%; p = 0.0.01). Thirty-day all-cause mortality was 13.3%. All patients presented with moderate/severe AR at baseline; at 30 days, 9.1% of implanted patients with data continued to have moderate and 1.4% severe AR. There was a significant reduction in residual moderate/severe AR from the CoreValve to Evolut R device (19.1% vs 6.3%, p = 0.02). Multivariable analysis revealed factors associated with 30-day all-cause mortality include number of valves used (hazard ratio [HR] 2.361, 1.643 to 3.391, p <0.001), albumin < 3.3 mg/dL (HR 3.358, 1.551 to 7.273, p=0.002), and left ventricular ejection fraction (HR 0.978, 0.957 to 1.000, p = 0.047). Despite higher 30-day all-cause mortality, self-expanding TAVI may be an option in selected patients with AR who have no surgical options.

Geographically Derived Socioeconomic Factors to Improve Risk Prediction in Patients Having Aortic Valve Replacement.

Socioeconomic status (SES) has been associated with adverse outcomes after cardiac surgery, but is not included in commonly applied risk adjustment models. This study evaluates whether inclusion of SES improves aortic valve replacement (AVR) risk prediction models, as this is the most common elective operation performed at our institution during the study period. All patients who underwent AVR at a single institution from 2005 to 2015 were evaluated. SES measures included unemployment, poverty, household income, home value, educational attainment, housing density, and a validated SES index score. The risk scores for mortality, complications, and increased length of stay were generated using models published by the Society for Thoracic Surgeons. Univariate models were fitted for each SES covariate and multivariable models for mortality, any complication, and prolonged length of stay (PLOS). A total of 1,386 patients underwent AVR with a 2.7% mortality, 15.1% complication rate, and 9.7% PLOS. In univariate models, higher education was associated with decreased mortality (odds ratio [OR] 0.96, p = 0.04) and complications (OR 0.97, p <0.01). Poverty was associated with increased length of stay (OR 1.02, p = 0.02). In the multivariable models, the inclusion of SES covariates increased the area under the curve for mortality (0.735 to 0.750, p = 0.14), for any complications (0.663 to 0.680, p <0.01), and for PLOS (0.749 to 0.751, p = 0.12). The inclusion of census-tract-level socioeconomic factors into the the Society of Thoracic Surgeons risk predication models is new and shows potential to improve risk prediction for outcomes after cardiac surgery. With the possibility of reimbursement and institutional ranking based on these outcomes, this study represents an improvement in risk prediction model.

Association of Tricuspid Regurgitation With Transcatheter Aortic Valve Replacement Outcomes: A Report From The Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry.

BACKGROUND: The purpose of this study is to evaluate the association of tricuspid regurgitation (TR) severity with outcomes after transcatheter aortic valve replacement (TAVR). METHODS: We analyzed data from 34,576 patients who underwent TAVR at 365 US hospitals from November 2011 through March 2015 submitted to The Society of Thoracic Surgeon/American College of Cardiology Transcatheter Valve Therapy Registry. We examined unadjusted mortality and heart failure readmission stratified by degree of preoperative TR and used multivariable models for 1-year mortality and heart failure readmission. RESULTS: Tricuspid regurgitation was present in 80% (n = 27,804) of TAVR patients, with mild TR in 56% (n = 19,393), moderate TR in 19% (n = 6687), and severe TR in 5% (n = 1,724). Increasing TR severity was associated with a number of comorbidities and The Society of Thoracic Surgeons predicted risk of mortality increased (p < 0.001): no TR (7.3 ± 5.4); mild TR (8.0 ± 5.7); moderate TR (9.6 ± 6.8); and severe TR (10.7 ± 7.4). In unadjusted analysis, moderate and severe TR were associated with increased use of cardiopulmonary bypass, longer intensive care unit and hospital stays, new dialysis, inhospital major adverse cardiac event, inhospital mortality, observed-to-expected inhospital mortality ratio, long-term heart failure readmission, and mortality (p < 0.001). Adjusted mortality at 1 year was significantly worse for patients with severe TR when left ventricular ejection fraction greater than 30% (hazard ratio 1.29, 95% confidence interval: 1.11 to 1.50) as was heart failure readmission (hazard ratio 1.27, 95% confidence interval: 1.04 to 1.54). CONCLUSIONS: Tricuspid regurgitation was common among patients undergoing TAVR. Increasing TR severity was associated with higher risk patients and increased mortality and readmission-particularly for patients with severe TR and left ventricular ejection fraction greater than 30%. The effectiveness of TAVR alone in patients with aortic stenosis and concomitant severe TR may warrant further consideration, particularly for lower risk patients.

Outcomes, readmissions, and costs in transfemoral and alterative access transcatheter aortic valve replacement in the US Medicare population.

OBJECTIVE: To comprehensively evaluate and compare utilization, outcomes, and especially costs of transfemoral (TF), transapical (TA), and transaortic (TAO) transcatheter aortic valve replacement (TAVR). METHODS: All Medicare fee-for-service patients undergoing TF (n = 4065), TA (n = 691), or TAO (n = 274) TAVR between January 1, 2011, and November 30, 2012, were identified using Health Care Procedure Classification Codes present on Medicare claims. Hospital charges from Medicare claims were converted to costs using hospital-specific Medicare cost-to-charge ratios. RESULTS: TA and TAO patients were similar in age, race, and common comorbidities. Compared with TF patients, TA and TAO patients were more likely to be female and to have peripheral vascular disease, chronic lung disease, and renal failure. Thirty-day mortality rates were higher among TA and TAO patients than among TF patients (TA, 9.6%; TAO, 8.0%; TF, 5.0%; P < .001). Adjusted mortality beyond 1 year did not differ by access. TA patients were more likely to require cardiopulmonary bypass (CPB). Increased adjusted mortality was associated with CPB (hazard ratio, 2.13; P < .01) and increased 30-day cost ($62,000 [interquartile range (IQR)], $45,100-$86,400 versus $48,800 [IQR, $38,100-$62,900]; P < .01). Cost at 30 days was lowest for TF ($48,600) compared with TA ($49,800; P < .01) and TAO ($53,200; P = .03). CONCLUSIONS: For patients ineligible to receive TF TAVR, TAO and TA approaches offer similar clinical outcomes at similar cost with acceptable operative and 1-year survival, except for higher rates of CPB use in TA patients. CPB was associated with worse survival and increased costs.

Cost and contribution margin of transcatheter versus surgical aortic valve replacement.

OBJECTIVE: To compare the cost of and payments for transcatheter aortic valve replacement (TAVR), a novel and expensive technology, and surgical aortic valve replacement (SAVR). METHODS: Medicare claims provided hospital charges, payments, and outcomes between January and December 2012. Hospital costs and charges were estimated using hospital-specific cost-to-charge ratios. Costs and payments were examined in propensity score- matched TAVR and SAVR patients. RESULTS: Medicare spent $215,770,200 nationally on 4083 patients who underwent TAVR in 2012. Hospital costs were higher for TAVR patients (median, $50,200; interquartile range [IQR], $39,800-$64,300) than for propensity-matched SAVR patients ($45,500; IQR, $34,500-$63,300; P < .01), owing largely to higher estimated medical supply costs, including the implanted valve prosthesis. Postprocedure hospital length of stay (LOS) length was shorter for TAVR patients (median, 5 days [IQR, 4-8 days] vs 7 days [IQR, 5-9 days]; P < .01), as was total intensive care unit (ICU) LOS (median, 2 days [IQR, 0-5 days] vs 3 days [IQR, 1-6 days]; P < .01). Medicare payments were lower for TAVR hospitalizations (median, $49,500; IQR, $36,900-$64,600) than for SAVR (median, $50,400; IQR, $37,400-$65,800; P < .01). The median of the differences between payments and costs (contribution margin) was -$3380 for TAVR hospitalizations and $2390 for SAVR hospitalizations (P < .01). CONCLUSIONS: TAVR accounted for $215 million in Medicare payments in its first year of clinical use. Among SAVR Medicare patients at a similar risk level, TAVR was associated with higher hospital costs despite shorter ICU LOS and hospital LOS. Overall and/or medical device cost reductions are needed for TAVR to have a net neutral financial impact on hospitals.

Association of Liability Concerns with Decisions to Order Echocardiography and Cardiac Stress Tests with Imaging.

BACKGROUND: Professional societies have made efforts to curb overuse of cardiac imaging and decrease practice variation by publishing appropriate use criteria. However, little is known about the impact of physician-level determinants such as liability concerns and risk aversion on decisions to order testing. METHODS: A web-based survey was administered to cardiologists and general practice physicians affiliated with two academic institutions. The survey consisted of four clinical scenarios in which appropriate use criteria rated echocardiography or stress testing as "may be appropriate." Respondents' degree of liability concerns and risk aversion were measured using validated tools. The primary outcome variable was tendency to order imaging, calculated as the average likelihood to order an imaging test across the clinical scenarios (1 = very unlikely, 6 = very likely). Linear regression models were used to evaluate the association between tendency to order imaging and physician characteristics. RESULTS: From 420 physicians invited to participate, 108 complete responses were obtained (26% response rate, 54% cardiologists). There was no difference in tendency to order imaging between cardiologists and general practice physicians (3.46 [95% CI, 3.12-3.81] vs 3.15 [95% CI, 2.79-3.51], P = .22). On multivariate analysis, a higher degree of liability concerns was the only significant predictor of decisions to order imaging (mean difference in tendency to order imaging, 0.36; 95% CI, 0.09-0.62; P = .01). CONCLUSION: In clinical situations in which performance of cardiac imaging is rated as "may be appropriate" by appropriate use criteria, physicians with higher liability concerns ordered significantly more testing than physicians with lower concerns.

Unconventional Volume-Outcome Associations in Adult Extracorporeal Membrane Oxygenation in the United States.

BACKGROUND: The aim of this study was to evaluate institutional volume-outcome relationships in extracorporeal membrane oxygenation (ECMO) with subanalyses of ECMO in patients with a primary diagnosis of respiratory failure. METHODS: All institutions with adult ECMO discharges in the Nationwide Inpatient Sample from 2002 to 2011 were evaluated. International Classification of Diseases (ninth revision) codes were used to identify ECMO-treated patients, indications, and concurrent procedures. Patients who were treated with ECMO after cardiotomy were excluded. Annual institutional and national volume of ECMO hospitalizations varied widely, hence the number of ECMO cases performed at an institution was calculated for each year independently. Institutions were grouped into high-, medium-, and low-volume terciles by year. Statistical analysis included hierarchical, multivariable logistic regression. RESULTS: The in-hospital mortality rates for ECMO admissions at low-, medium-, and high-volume ECMO centers were 48% (n = 467), 60% (n = 285), and 57% (n = 445), respectively (p = 0.001). In post hoc pairwise comparisons, patients in low-volume hospitals were more likely to survive to discharge compared with patients in medium-volume (p = 0.001) and high-volume (p = 0.005) hospitals. There was no significant difference in survival between medium-volume and high-volume hospitals (p = 0.81). In a subanalysis of patients with respiratory failure, low-volume ECMO centers maintained the lowest rates of in-hospital mortality (47%), versus 61% in medium-volume institutions (p = 0.045) and 56% in high-volume institutions (p = 0.15). Multivariable logistical regression produced similar results in the entire study sample and in patients with respiratory failure. CONCLUSIONS: ECMO outcomes in the Nationwide Inpatient Sample do not follow a traditional volume-outcome relationship, and these results suggest that, in properly selected patients, ECMO can be performed with acceptable results in U.S. centers that do not perform a high volume of ECMO.

Cardiac Stress Test Trends Among US Patients Younger Than 65 Years, 2005-2012.

IMPORTANCE: After a period of rapid growth, use of cardiac stress testing has recently decreased among Medicare beneficiaries and in a large integrated health system. However, it is not known whether declines in cardiac stress testing are universal or are confined to certain populations. OBJECTIVE: To determine trends in rates of cardiac stress testing among a large and diverse cohort of commercially insured patients. DESIGN, SETTING, AND PARTICIPANTS: A serial cross-sectional study with time trends was conducted using administrative claims from all members aged 25 to 64 years belonging to a large, national managed care company from January 1, 2005, to December 31, 2012. Linear trends in rates were determined using negative binomial regression models with procedure count as the dependent variable, calendar quarter as the key independent variable, and the size of the population as a logged offset term. Data analysis was performed from January 1, 2005, to December 31, 2012. MAIN OUTCOMES AND MEASURES: Age- and sex-adjusted rates of cardiac stress tests per calendar quarter (reported as number of tests per 100 000 person-years). RESULTS: A total of 2 085 591 cardiac stress tests were performed among 32 921 838 persons (mean [SD] age, 43.2 [10.9] years; 16 625 528 women [50.5%] and 16 296 310 [49.5%] men; 7 604 945 nonwhite [23.1%]). There was a 3.0% increase in rates of cardiac stress testing from 2005 (3486 tests; 95% CI, 3458-3514) to 2012 (3589 tests; 95% CI, 3559-3619; P = .01 for linear trend). Use of nuclear single-photon emission computed tomography decreased by 14.9% from 2005 (1907 tests; 95% CI, 1888-1926) to 2012 (1623 tests; 95% CI, 1603-1643; P = .03). Use of stress echocardiography increased by 27.8% from 2005 (709 tests; 95% CI, 697-721) to 2012 (906 tests; 95% CI, 894 to 920; P < .001). Use of exercise electrocardiography increased by 12.5% from 2005 (861 tests; 95% CI, 847-873) to 2012 (969 tests; 95% CI, 953-985; P < .001). Use of other stress testing modalities increased 65.5% from 2006 (55 tests; 95% CI, 51-59) to 2012 (91 tests; 95% CI, 87-95; P < .001). For individuals aged 25 to 34 years, rates of cardiac stress testing increased 59.1% from 2005 (543 tests; 95% CI, 532-554) to 2012 (864 tests; 95% CI, 852-876; P < .001). For individuals aged 55 to 64 years, rates of cardiac stress testing decreased by 12.3% from 2005 (7894 tests; 95% CI, 7820-7968) to 2012 (6923 tests; 95% CI, 6853-6993; P < .001). CONCLUSIONS AND RELEVANCE: In contrast to declines in the use of cardiac stress testing in some health care systems, we observed a small increase in its use among a nationally representative cohort of commercially insured patients. Our findings suggest that observed trends in the use of cardiac stress testing may have been driven more by unique characteristics of populations and health systems than national efforts to reduce the overuse of testing.