James R. Edgerton M.D.

Pollock, B. D., G. Filardo, B. da Graca, T. K. Phan, G. Ailawadi, V. Thourani, R. J. Damiano, Jr. and J. R. Edgerton (2018). “Predicting New-Onset Post-Coronary Artery Bypass Graft Atrial Fibrillation With Existing Risk Scores.” Ann Thorac Surg 105(1): 115-121.

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BACKGROUND: New-onset atrial fibrillation (AF) after coronary artery bypass graft (CABG) operation is associated with poorer survival. Blanket prophylaxis efforts have not appreciably decreased incidence, making targeted prevention for high-risk patients desirable. We compared predictive abilities of existing scores developed/used to predict adverse CABG outcomes (Society of Thoracic Surgeons’ [STS] risk of mortality) or AF not associated with cardiac operation (the Cohorts for Heart and Aging Research in Genomic Epidemiology [CHARGE]-AF score, the CHA2DS2-VASc score), and a risk model for predicting postoperative AF following cardiac operations (POAF score), with age (the most consistently identified post-CABG AF risk factor). METHODS: Data submitted to the STS Adult Cardiac Surgery Database were used to assess new-onset AF in 8,976 consecutive patients without preoperative AF undergoing isolated CABG from 2004 to 2010 at five participating centers. Five logistic regression models (for CHA2DS2-VASc score, CHARGE-AF score, POAF score, STS risk score, and age, respectively, all modeled with restricted cubic splines) with a random effect for site were fitted to predict post-CABG AF. Estimates were used to compute and compare receiver operating characteristic (ROC) areas. RESULTS: New-onset AF occurred in 2,141 patients (23.9%). The ROC area was greatest for CHARGE-AF (0.68, 95% confidence interval [CI]: 0.67-0.69), followed by age (0.66, 95% CI: 0.65-0.68), POAF score (0.65, 95% CI: 0.64-0.66), CHA2DS2-VASc (0.59, 95% CI: 0.58 to 0.60), and STS risk of mortality (0.58, 95% CI: 0.56-0.59). CHARGE-AF was significantly more predictive than age (p < 0.0001); the other scores were significantly less predictive (p < 0.0001). CONCLUSIONS: Only CHARGE-AF performed better than age alone. Its performance was moderate and comparable with published risk models specifically targeted at new-onset post-isolated CABG AF. Future research should continue to focus on developing better predictive models.

Pollock, B. D., G. Filardo, B. da Graca, T. K. Phan, G. Ailawadi, V. Thourani, R. J. Damiano, Jr. and J. R. Edgerton (2017). “Predicting new-onset post-coronary artery bypass graft atrial fibrillation with existing risk scores.” Ann Thorac Surg: 2017 Nov [Epub ahead of print].

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BACKGROUND: New-onset atrial fibrillation (AF) after coronary artery bypass graft (CABG) operation is associated with poorer survival. Blanket prophylaxis efforts have not appreciably decreased incidence, making targeted prevention for high-risk patients desirable. We compared predictive abilities of existing scores developed/used to predict adverse CABG outcomes (Society of Thoracic Surgeons’ [STS] risk of mortality) or AF not associated with cardiac operation (the Cohorts for Heart and Aging Research in Genomic Epidemiology [CHARGE]-AF score, the CHA2DS2-VASc score), and a risk model for predicting postoperative AF following cardiac operations (POAF score), with age (the most consistently identified post-CABG AF risk factor). METHODS: Data submitted to the STS Adult Cardiac Surgery Database were used to assess new-onset AF in 8,976 consecutive patients without preoperative AF undergoing isolated CABG from 2004 to 2010 at five participating centers. Five logistic regression models (for CHA2DS2-VASc score, CHARGE-AF score, POAF score, STS risk score, and age, respectively, all modeled with restricted cubic splines) with a random effect for site were fitted to predict post-CABG AF. Estimates were used to compute and compare receiver operating characteristic (ROC) areas. RESULTS: New-onset AF occurred in 2,141 patients (23.9%). The ROC area was greatest for CHARGE-AF (0.68, 95% confidence interval [CI]: 0.67-0.69), followed by age (0.66, 95% CI: 0.65-0.68), POAF score (0.65, 95% CI: 0.64-0.66), CHA2DS2-VASc (0.59, 95% CI: 0.58 to 0.60), and STS risk of mortality (0.58, 95% CI: 0.56-0.59). CHARGE-AF was significantly more predictive than age (p < 0.0001); the other scores were significantly less predictive (p < 0.0001). CONCLUSIONS: Only CHARGE-AF performed better than age alone. Its performance was moderate and comparable with published risk models specifically targeted at new-onset post-isolated CABG AF. Future research should continue to focus on developing better predictive models.

Filardo, G., B. D. Pollock and J. Edgerton (2017). “Categorizing body mass index biases assessment of the association with post-coronary artery bypass graft mortality.” Eur J Cardiothorac Surg 52(5): 924-929.

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OBJECTIVES: The high prevalence of obesity makes accurately estimating the impact of anthropometric measures on cardiac surgery outcomes critical. The Society of Thoracic Surgeons coronary artery bypass graft (CABG) surgery risk model includes body surface area (as a continuous variable, using spline functions), but most studies apply various categorizations of body mass index (BMI)-contributing to the contradictory published findings. We assessed the association between BMI (modelled as a continuous variable without assumptions of linearity) and CABG operative mortality and examined the impact of applying previous studies’ BMI modelling strategies. METHODS: We identified 25 studies investigating the BMI-operative mortality association: 22 categorized BMI, 2 as a linear continuous variable,1 used spline functions. Our cohort of 12 715 consecutive patients underwent isolated CABG at 32 cardiac surgery programmes in North Texas from 1 January 2008-31 December 2012. BMI was modelled using restricted cubic spline functions in a propensity-adjusted model (controlling for Society of Thoracic Surgeons risk factors) estimating operative mortality. The analysis was repeated using each categorization identified and modelling BMI as a linear continuous variable. RESULTS: BMI (modelled with a restricted cubic spline) was significantly associated with operative mortality (P < 0.0001). Risk was lowest for BMI near 30 kg/m2 and highest below 20 kg/m2 and above 40 kg/m2. No categorization, nor the linear continuous model, fully captured this association. CONCLUSIONS: BMI is strongly associated with CABG operative mortality. Categorizing BMI (or assuming a linear relationship) heavily biases estimates of its association with post-CABG mortality. In general, smoothing techniques should be used for all continuous risk factors to avoid bias.

Calkins, H., G. Hindricks, R. Cappato, Y. H. Kim, E. B. Saad, L. Aguinaga, J. G. Akar, V. Badhwar, J. Brugada, J. Camm, P. S. Chen, S. A. Chen, M. K. Chung, J. C. Nielsen, A. B. Curtis, D. Wyn Davies, J. D. Day, A. d’Avila, N. de Groot, L. Di Biase, M. Duytschaever, J. R. Edgerton, K. A. Ellenbogen, P. T. Ellinor, S. Ernst, G. Fenelon, E. P. Gerstenfeld, D. E. Haines, M. Haissaguerre, R. H. Helm, E. Hylek, W. M. Jackman, J. Jalife, J. M. Kalman, J. Kautzner, H. Kottkamp, K. H. Kuck, K. Kumagai, R. Lee, T. Lewalter, B. D. Lindsay, L. Macle, M. Mansour, F. E. Marchlinski, G. F. Michaud, H. Nakagawa, A. Natale, S. Nattel, K. Okumura, D. Packer, E. Pokushalov, M. R. Reynolds, P. Sanders, M. Scanavacca, R. Schilling, C. Tondo, H. M. Tsao, A. Verma, D. J. Wilber and T. Yamane (2017). “2017 hrs/ehra/ecas/aphrs/solaece expert consensus statement on catheter and surgical ablation of atrial fibrillation: Executive summary.” J Interv Card Electrophysiol: 2017 Sep [Epub ahead of print].

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During the past three decades, catheter and surgical ablation of atrial fibrillation (AF) have evolved from investigational procedures to their current role as effective treatment options for patients with AF. Surgical ablation of AF, using either standard, minimally invasive, or hybrid techniques, is available in most major hospitals throughout the world. Catheter ablation of AF is even more widely available, and is now the most commonly performed catheter ablation procedure.

Calkins, H., G. Hindricks, R. Cappato, Y. H. Kim, E. B. Saad, L. Aguinaga, J. G. Akar, V. Badhwar, J. Brugada, J. Camm, P. S. Chen, S. A. Chen, M. K. Chung, J. C. Nielsen, A. B. Curtis, D. Wyn Davies, J. D. Day, A. d’Avila, N. de Groot, L. Di Biase, M. Duytschaever, J. R. Edgerton, K. A. Ellenbogen, P. T. Ellinor, S. Ernst, G. Fenelon, E. P. Gerstenfeld, D. E. Haines, M. Haissaguerre, R. H. Helm, E. Hylek, W. M. Jackman, J. Jalife, J. M. Kalman, J. Kautzner, H. Kottkamp, K. H. Kuck, K. Kumagai, R. Lee, T. Lewalter, B. D. Lindsay, L. Macle, M. Mansour, F. E. Marchlinski, G. F. Michaud, H. Nakagawa, A. Natale, S. Nattel, K. Okumura, D. Packer, E. Pokushalov, M. R. Reynolds, P. Sanders, M. Scanavacca, R. Schilling, C. Tondo, H. M. Tsao, A. Verma, D. J. Wilber and T. Yamane (2017). “2017 hrs/ehra/ecas/aphrs/solaece expert consensus statement on catheter and surgical ablation of atrial fibrillation: Executive summary.” J Interv Card Electrophysiol: 2017 Sep [Epub ahead of print].

Full text of this article.

During the past three decades, catheter and surgical ablation of atrial fibrillation (AF) have evolved from investigational procedures to their current role as effective treatment options for patients with AF. Surgical ablation of AF, using either standard, minimally invasive, or hybrid techniques, is available in most major hospitals throughout the world. Catheter ablation of AF is even more widely available, and is now the most commonly performed catheter ablation procedure.