Stroke is a serious complication following transcatheter aortic valve replacement (TAVR), yet pre... more Stroke is a serious complication following transcatheter aortic valve replacement (TAVR), yet predictive models are not available. A new risk model for in-hospital stroke following TAVR was developed and used to estimate site-specific performance. We included 97,600 TAVR procedures from 521 sites in the STS/ACC Transcatheter Valve Therapy (TVT) Registry from July 2014 through June 2017. Association between baseline covariates and in-hospital stroke was estimated by logistic regression. Discrimination was evaluated by C statistic. Calibration was tested internally via cross validation. Hierarchical modeling was used to estimate risk-adjusted site-specific performance. Median age was 82 years, 44,926 (46.0%) were female, and 1,839 (1.9%) had in-hospital stroke. Covariates associated with stroke (odds ratio) included transapical access (1.44), access excluding transapical and transfemoral (1.77), prior stroke (1.57), prior TIA (1.50), pre-procedural shock, inotropes or mechanical assist device (1.48), smoking (1.28), porcelain aorta (1.23), peripheral arterial disease (1.21), age per 5 years (1.11), glomerular filtration rate per 5 ml/min (0.97), body surface area per m (0.55 male; 0.43 female), and prior aortic valve (0.78) and non-aortic valvular (0.42) procedures. The C statistic was 0.622. Calibration curves demonstrated agreement between observed and expected stroke rates. Hierarchical modeling showed 10 centers (1.9%) with significantly higher odds ratios for in-hospital stroke than their peers. A risk model for in-hospital stroke following TAVR was developed from the STS/ACC TVT Registry and used to estimate site-specific stroke performance. This model can serve as a valuable resource for quality improvement, clinical decision-making, and patient counseling.
Circulation. Cardiovascular quality and outcomes, 2018
Background Among clinical trial patients at high surgical risk, a model has been developed and ex... more Background Among clinical trial patients at high surgical risk, a model has been developed and externally validated to estimate patient risk for poor outcomes after transcatheter aortic valve replacement (TAVR). How this model performs in lower risk and unselected patients is not known. We sought to examine and optimize the performance of the TAVR poor outcome risk model among patients in the US Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry. Methods and Results Among 13 351 patients who underwent TAVR at 252 US sites between November 9, 2011 and June 30, 2015, the rate of poor outcome at 1 year after TAVR was 38.9%, which was because of death in 20.7% and poor quality of life or quality of life decline in 18.2%. The rate of poor outcome has decreased slightly over time, from 42.0% in 2012 to 37.8% in 2015 ( P for trend=0.076). The original TAVR poor outcome risk model did not calibrate well on this population. We then reestimated th...
The last published version of the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Databa... more The last published version of the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) risk models were developed in 2008 based on patient data from 2002 to 2006 and have been periodically recalibrated. In response to evolving changes in patient characteristics, risk profiles, surgical practice, and outcomes, STS has now developed a set of entirely new risk models for adult cardiac surgery. New models were estimated for isolated coronary artery bypass grafting surgery (CABG, n = 439,092), isolated aortic or mitral valve surgery (n = 150,150), and combined valve + CABG (n = 81,588) procedures. The development set was based on July 2011 to June 2014 STS-ACSD data; validation was performed using July 2014 to December 2016 data. Separate models were developed for operative mortality, stroke, renal failure, prolonged ventilation, reoperation, composite major morbidity or mortality, and prolonged or short postoperative length of stay. Because of its low occurrence rate...
The aim of this study was to develop and validate a risk adjustment model for 30-day mortality af... more The aim of this study was to develop and validate a risk adjustment model for 30-day mortality after transcatheter aortic valve replacement (TAVR) that accounted for both standard clinical factors and pre-procedural health status and frailty. Assessment of risk for TAVR is important both for patient selection and provider comparisons. Prior efforts for risk adjustment have focused on in-hospital mortality, which is easily obtainable but can be biased because of early discharge of ill patients. Using data from patients who underwent TAVR as part of the Society of Thoracic Surgeons/American College of Cardiology TVT (Transcatheter Valve Therapy) Registry (June 2013 to May 2016), a hierarchical logistic regression model to estimate risk for 30-day mortality after TAVR based only on pre-procedural factors and access site was developed and internally validated. The model included factors from the original TVT Registry in-hospital mortality model but added the Kansas City Cardiomyopathy Q...
Journal of the American College of Cardiology, Jan 4, 2017
Transcatheter aortic valve replacement (TAVR) has been introduced into U.S. clinical practice wit... more Transcatheter aortic valve replacement (TAVR) has been introduced into U.S. clinical practice with efforts to optimize outcomes and minimize the learning curve. The goal of this study was to assess the degree to which increasing experience during the introduction of this procedure, separated from other outcome determinants including patient and procedural characteristics, is associated with outcomes. The authors evaluated the association of hospital TAVR volume and patient outcomes for TAVR by using data from 42,988 commercial procedures conducted at 395 hospitals submitting to the Transcatheter Valve Therapy Registry from 2011 through 2015. Outcomes assessed included adjusted and unadjusted in-hospital major adverse events. Increasing site volume was associated with lower in-hospital risk-adjusted outcomes, including mortality (p < 0.02), vascular complications (p < 0.003), and bleeding (p < 0.001) but was not associated with stroke (p = 0.14). From the first case to the 4...
Journal of the American College of Cardiology, Jan 2, 2016
The STS/ACC Transcatheter Valve Therapy (TVT) Registry captures all procedures with Food and Drug... more The STS/ACC Transcatheter Valve Therapy (TVT) Registry captures all procedures with Food and Drug Administration (FDA) approved transcatheter valve devices performed in the United States and is mandated as a condition of reimbursement by a Centers for Medicaid and Medicare Services (CMS) OBJECTIVES: This annual report focuses on patient characteristics, trends, and outcomes of transcatheter aortic and mitral valve catheter-based valve procedures in the United States. Data for all patients receiving commercially approved devices from 2012 through December 31, 2015 are entered in the TVT Registry. The 54,782 TAVR patients demonstrated decreases in expected risk of 30-day operative mortality (STS PROM) 7% to 6% and TAVR PROM (TVT PROM) 4% to 3% (both p<.0001) from 2012 to 2015. Observed in-hospital mortality decreased from 5.7% to 2.9% and one-year mortality decreased from 25.8% to 21.6. However, 30-day post procedure pacemaker insertion increased from 8.8% in 2013 to 12.0% in 2015....
Circulation. Cardiovascular quality and outcomes, Sep 13, 2016
The use of transcatheter aortic valve replacement (TAVR) to treat aortic stenosis in the United S... more The use of transcatheter aortic valve replacement (TAVR) to treat aortic stenosis in the United States is growing, yet little is known about the variation in procedural outcomes in community practice. We developed a TAVR in-hospital mortality risk model and used it to quantify variation in mortality rates across United States (US) TAVR centers. We analyzed data from 22 248 TAVR procedures performed at 318 sites participating in the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry (November 2011 to October 2014). A Bayesian hierarchical model was developed to estimate hospital-specific risk-adjusted mortality rates adjusting for 40 patient baseline factors. A total of 1130 in-hospital deaths (5.1%) were observed. Reliability-adjusted risk-adjusted mortality rate estimates ranged from 3.4% to 7.7% with an interquartile range of 4.8% to 5.4%. A patient's predicted odds of dying was 80% higher if treated by a hospital 1 standard deviat...
The relatively new field of artificial intelligence has spawned a variety of techniques associate... more The relatively new field of artificial intelligence has spawned a variety of techniques associated with computer-assisted diagnosis. These techniques have been applied to the diagnosis of pulmonary lesions, but previous reports have focused on medical rather than surgical populations and the results have been evaluated using only retrospective patient surveys. We used a Bayesian algorithm to develop a diagnostic computer model for prospectively evaluating patients undergoing thoracotomy for suspected pulmonary malignancy. Patients who had a preoperative diagnosis were not included. Preoperative clinical and radiographic parameters for 100 consecutive patients were prospectively entered into the diagnostic model, which then categorized the lesion as benign or malignant. The computer predictions agreed with the final histological diagnosis in 95 of the 100 patients. The sensitivity was 96% and the specificity was 89% for this prospective series. These results indicate that the computer-assisted diagnosis of pulmonary lesions may have a role in this clinical setting.
Stroke is a serious complication following transcatheter aortic valve replacement (TAVR), yet pre... more Stroke is a serious complication following transcatheter aortic valve replacement (TAVR), yet predictive models are not available. A new risk model for in-hospital stroke following TAVR was developed and used to estimate site-specific performance. We included 97,600 TAVR procedures from 521 sites in the STS/ACC Transcatheter Valve Therapy (TVT) Registry from July 2014 through June 2017. Association between baseline covariates and in-hospital stroke was estimated by logistic regression. Discrimination was evaluated by C statistic. Calibration was tested internally via cross validation. Hierarchical modeling was used to estimate risk-adjusted site-specific performance. Median age was 82 years, 44,926 (46.0%) were female, and 1,839 (1.9%) had in-hospital stroke. Covariates associated with stroke (odds ratio) included transapical access (1.44), access excluding transapical and transfemoral (1.77), prior stroke (1.57), prior TIA (1.50), pre-procedural shock, inotropes or mechanical assist device (1.48), smoking (1.28), porcelain aorta (1.23), peripheral arterial disease (1.21), age per 5 years (1.11), glomerular filtration rate per 5 ml/min (0.97), body surface area per m (0.55 male; 0.43 female), and prior aortic valve (0.78) and non-aortic valvular (0.42) procedures. The C statistic was 0.622. Calibration curves demonstrated agreement between observed and expected stroke rates. Hierarchical modeling showed 10 centers (1.9%) with significantly higher odds ratios for in-hospital stroke than their peers. A risk model for in-hospital stroke following TAVR was developed from the STS/ACC TVT Registry and used to estimate site-specific stroke performance. This model can serve as a valuable resource for quality improvement, clinical decision-making, and patient counseling.
Circulation. Cardiovascular quality and outcomes, 2018
Background Among clinical trial patients at high surgical risk, a model has been developed and ex... more Background Among clinical trial patients at high surgical risk, a model has been developed and externally validated to estimate patient risk for poor outcomes after transcatheter aortic valve replacement (TAVR). How this model performs in lower risk and unselected patients is not known. We sought to examine and optimize the performance of the TAVR poor outcome risk model among patients in the US Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry. Methods and Results Among 13 351 patients who underwent TAVR at 252 US sites between November 9, 2011 and June 30, 2015, the rate of poor outcome at 1 year after TAVR was 38.9%, which was because of death in 20.7% and poor quality of life or quality of life decline in 18.2%. The rate of poor outcome has decreased slightly over time, from 42.0% in 2012 to 37.8% in 2015 ( P for trend=0.076). The original TAVR poor outcome risk model did not calibrate well on this population. We then reestimated th...
The last published version of the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Databa... more The last published version of the Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database (ACSD) risk models were developed in 2008 based on patient data from 2002 to 2006 and have been periodically recalibrated. In response to evolving changes in patient characteristics, risk profiles, surgical practice, and outcomes, STS has now developed a set of entirely new risk models for adult cardiac surgery. New models were estimated for isolated coronary artery bypass grafting surgery (CABG, n = 439,092), isolated aortic or mitral valve surgery (n = 150,150), and combined valve + CABG (n = 81,588) procedures. The development set was based on July 2011 to June 2014 STS-ACSD data; validation was performed using July 2014 to December 2016 data. Separate models were developed for operative mortality, stroke, renal failure, prolonged ventilation, reoperation, composite major morbidity or mortality, and prolonged or short postoperative length of stay. Because of its low occurrence rate...
The aim of this study was to develop and validate a risk adjustment model for 30-day mortality af... more The aim of this study was to develop and validate a risk adjustment model for 30-day mortality after transcatheter aortic valve replacement (TAVR) that accounted for both standard clinical factors and pre-procedural health status and frailty. Assessment of risk for TAVR is important both for patient selection and provider comparisons. Prior efforts for risk adjustment have focused on in-hospital mortality, which is easily obtainable but can be biased because of early discharge of ill patients. Using data from patients who underwent TAVR as part of the Society of Thoracic Surgeons/American College of Cardiology TVT (Transcatheter Valve Therapy) Registry (June 2013 to May 2016), a hierarchical logistic regression model to estimate risk for 30-day mortality after TAVR based only on pre-procedural factors and access site was developed and internally validated. The model included factors from the original TVT Registry in-hospital mortality model but added the Kansas City Cardiomyopathy Q...
Journal of the American College of Cardiology, Jan 4, 2017
Transcatheter aortic valve replacement (TAVR) has been introduced into U.S. clinical practice wit... more Transcatheter aortic valve replacement (TAVR) has been introduced into U.S. clinical practice with efforts to optimize outcomes and minimize the learning curve. The goal of this study was to assess the degree to which increasing experience during the introduction of this procedure, separated from other outcome determinants including patient and procedural characteristics, is associated with outcomes. The authors evaluated the association of hospital TAVR volume and patient outcomes for TAVR by using data from 42,988 commercial procedures conducted at 395 hospitals submitting to the Transcatheter Valve Therapy Registry from 2011 through 2015. Outcomes assessed included adjusted and unadjusted in-hospital major adverse events. Increasing site volume was associated with lower in-hospital risk-adjusted outcomes, including mortality (p < 0.02), vascular complications (p < 0.003), and bleeding (p < 0.001) but was not associated with stroke (p = 0.14). From the first case to the 4...
Journal of the American College of Cardiology, Jan 2, 2016
The STS/ACC Transcatheter Valve Therapy (TVT) Registry captures all procedures with Food and Drug... more The STS/ACC Transcatheter Valve Therapy (TVT) Registry captures all procedures with Food and Drug Administration (FDA) approved transcatheter valve devices performed in the United States and is mandated as a condition of reimbursement by a Centers for Medicaid and Medicare Services (CMS) OBJECTIVES: This annual report focuses on patient characteristics, trends, and outcomes of transcatheter aortic and mitral valve catheter-based valve procedures in the United States. Data for all patients receiving commercially approved devices from 2012 through December 31, 2015 are entered in the TVT Registry. The 54,782 TAVR patients demonstrated decreases in expected risk of 30-day operative mortality (STS PROM) 7% to 6% and TAVR PROM (TVT PROM) 4% to 3% (both p<.0001) from 2012 to 2015. Observed in-hospital mortality decreased from 5.7% to 2.9% and one-year mortality decreased from 25.8% to 21.6. However, 30-day post procedure pacemaker insertion increased from 8.8% in 2013 to 12.0% in 2015....
Circulation. Cardiovascular quality and outcomes, Sep 13, 2016
The use of transcatheter aortic valve replacement (TAVR) to treat aortic stenosis in the United S... more The use of transcatheter aortic valve replacement (TAVR) to treat aortic stenosis in the United States is growing, yet little is known about the variation in procedural outcomes in community practice. We developed a TAVR in-hospital mortality risk model and used it to quantify variation in mortality rates across United States (US) TAVR centers. We analyzed data from 22 248 TAVR procedures performed at 318 sites participating in the Society of Thoracic Surgeons/American College of Cardiology Transcatheter Valve Therapy Registry (November 2011 to October 2014). A Bayesian hierarchical model was developed to estimate hospital-specific risk-adjusted mortality rates adjusting for 40 patient baseline factors. A total of 1130 in-hospital deaths (5.1%) were observed. Reliability-adjusted risk-adjusted mortality rate estimates ranged from 3.4% to 7.7% with an interquartile range of 4.8% to 5.4%. A patient's predicted odds of dying was 80% higher if treated by a hospital 1 standard deviat...
The relatively new field of artificial intelligence has spawned a variety of techniques associate... more The relatively new field of artificial intelligence has spawned a variety of techniques associated with computer-assisted diagnosis. These techniques have been applied to the diagnosis of pulmonary lesions, but previous reports have focused on medical rather than surgical populations and the results have been evaluated using only retrospective patient surveys. We used a Bayesian algorithm to develop a diagnostic computer model for prospectively evaluating patients undergoing thoracotomy for suspected pulmonary malignancy. Patients who had a preoperative diagnosis were not included. Preoperative clinical and radiographic parameters for 100 consecutive patients were prospectively entered into the diagnostic model, which then categorized the lesion as benign or malignant. The computer predictions agreed with the final histological diagnosis in 95 of the 100 patients. The sensitivity was 96% and the specificity was 89% for this prospective series. These results indicate that the computer-assisted diagnosis of pulmonary lesions may have a role in this clinical setting.
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Papers by Fred Edwards