International Multicenter, Myopic and Myopic Astigmatism Femto LASIK, Customized by Automated Ray-Tracing Ablation Profile Calculation: A Postmarket Study.

Purpose: To assess the safety and efficacy of a customized ablation treatment (InnovEyes) to correct myopia and myopic astigmatism with femtosecond laser-assisted in situ keratomileusis (Femto LASIK). Patients and Methods: In this prospective, nonrandomized, multicenter study, 113 patients (225 eyes) with preoperative myopia less than -9.0 diopters (D) and astigmatism 0 to -4.0 D (based on InnovEyes refraction) underwent wavefront, tomography, and biometry assessment using a single diagnostic device (InnovEyes sightmap). These data were imported and used unmodified by the InnovEyes algorithm to automatically calculate and optimize correction of lower- and higher­order aberrations (HOAs) treated by the EX500 ablation profile. Visual acuity, refractive error, HOAs, and patient satisfaction were evaluated over 3 months. Results: A total of 106 patients (212 eyes) completed the study and were included in the analysis. Mean preoperative manifest refraction spherical equivalent (MRSE) was -3.38±1.76 D. At Month 3, uncorrected distance visual acuity was 20/20 or better in 208/212 (98.1%) eyes, and it was the same as, or better than, the preoperative best-corrected distance visual acuity (CDVA) in 162/212 (76.4%) eyes; 76/212 (35.8%) eyes gained ≥1 line of CDVA. MRSE was within ±0.5 D in 195/212 (92.0%) eyes. Additionally, 201/209 (96.2%) eyes had no change (defined as a change between -0.1 µm and 0.1 µm, inclusive) in HOAs, and 105/106 (99.1%) patients reported to be satisfied with the results. Conclusion: Customizing ray-tracing Femto LASIK with this platform appeared safe and effective in correcting myopic astigmatism and also achieved a significant percentage of eyes gaining lines of vision, potentially by addressing HOAs, along with a consistently high level of patient satisfaction.

Clinical comparison of 27-gauge and 23-gauge instruments on the outcomes of pars plana vitrectomy surgery for the treatment of vitreoretinal diseases.

PURPOSE OF REVIEW: To compare outcomes of 27-gauge and 23-gauge pars plana vitrectomy (PPV) for treatment of vitreoretinal diseases. RECENT FINDINGS: Sixty-eight patients undergoing microincisional PPV for treatment of vitreoretinal diseases were randomized 1 : 1 to 27-gauge or 23-gauge surgery with a 7500 cuts-per-minute vitrectomy probe. The most common reasons for vitrectomy were epiretinal membrane (49%) and vitreous hemorrhage (24%). Mean ±â€Šstandard deviation (SD) changes from immediate preoperative to immediate postoperative intraocular pressure were -0.40 ±â€Š6.60 mmHg in the 27-gauge and -3.05 ±â€Š7.64 mmHg in the 23-gauge group (adjusted mean difference 2.42 mmHg, 95% lower confidence limit 0.64, P = 0.013), but these changes were not associated with primary reason for vitrectomy (P = 0.065). Mean ±â€ŠSD conjunctival edema grades in the 27-gauge and 23-gauge groups 1 week after surgery were 0.02 ±â€Š0.124 and 0.10 ±â€Š0.246, respectively (least squares mean difference -0.09, 95% upper confidence limit -0.03, P = 0.004), and were 0.01 ±â€Š0.122 and 0.12 ±â€Š0.338, respectively, at the probe incision site. Conjunctival edema grades were similar in both groups at 1 and 3 months. Mean ±â€ŠSD pain ratings on postoperative day 1 - an indicator of patient comfort - were similar in the two groups. SUMMARY: Smaller diameter vitrectomy instruments are associated with smaller reductions in immediate postoperative intraocular pressure.

Retrospective analysis of an intraoperative aberrometry database: a study investigating absolute prediction in eyes implanted with low cylinder power toric intraocular lenses.

PURPOSE: To evaluate the spherical equivalent outcomes of intraoperative aberrometry (IA) power calculations compared with the surgeons' preoperative power calculations in eyes implanted with AcrySof® IQ T3 intraocular lenses (IOLs). PATIENTS AND METHODS: We assessed data collected by an IA system from multiple centers in the United States. Data was from patients who had undergone cataract extraction by phacoemulsification with the use of the Optiwave Refractive Analysis System and whose eyes had been implanted with model SN6AT3 (1.5 diopter [D] at IOL plane) aspheric lenses. The analysis was performed in 2 stages: hypothesis generation and confirmatory testing. Confirmatory endpoints were a comparison of absolute prediction errors for IA for the implanted IOL versus preoperative formula power calculations. DESIGN: Retrospective analysis of preoperative, intraoperative, and postoperative data concerning eyes implanted with model SN6AT3 (1.5 D) aspheric lenses from the AnalyzOR™ database. RESULTS: Mean absolute IA prediction error was significantly lower than preoperative prediction error (paired difference: -0.06 D; p<0.0001); this was mirrored by the median paired difference of -0.04 D (p<0.0001). For eyes where the power of the implanted IOL differed from the power of the preoperatively planned lens, mean and median paired differences in prediction errors were greater: -0.13 D (p<0.0001) and -0.15 D (p<0.0001), respectively. The percentage of eyes with prediction error ≤0.50 D was significantly higher with IA (83.4%, n=5388/6460) than with the preoperative formula (76.5%, n=4942/6460, p<0.0001). When the powers of the implanted IOL and the preoperatively planned lens were different, the percentage of eyes with prediction error ≤0.50 D was 83.3% (2155/2587) for IA and 68.8% (1781/2587, p<0.0001) for the preoperative formula. CONCLUSION: IA produces more accurate spherical equivalent outcomes for eyes implanted with a low toric IOL than the preoperative formulas.

Corneal Endothelial Cell Loss and Morphometric Changes 5 Years after Phacoemulsification with or without CyPass Micro-Stent.

PURPOSE: To characterize long-term changes in corneal endothelial cells after phacoemulsification with or without supraciliary Micro-Stent (Alcon) implantation in eyes with open-angle glaucoma (OAG) and visually significant cataract. DESIGN: Three-year safety extension of a 2-year randomized clinical trial. METHODS: Patients from the multicenter Study of an Implantable Device for Lowering Intraocular Pressure in Glaucoma Patients Undergoing Cataract Surgery (COMPASS) trial who underwent Micro-Stent implantation plus phacoemulsification (n = 282) or phacoemulsification alone (n = 67) were analyzed post hoc. Specular microscopy was used to assess endothelial cell loss (ECL), including changes from baseline in endothelial cell density (ECD), coefficient of variation, and percentage of hexagonal cells. RESULTS: Preoperative ECDs in the microstent group (2,432.6 cells/mm2 [95% confidence interval [CI], 2,382.8-2,482.4 cells/mm2]) were similar to those in the control group (2,434.5 cells/mm2 [95% CI, 2,356.5-2,512.4 cells/mm2]) groups. ECL at months 48 and 60 was greater in the Micro-Stent group than in the control group. At month 60, the mean percent of changes in ECD was -20.4% (95% CI, -23.5% to -17.5%) in the Micro-Stent group and -10.1% (95% CI, -13.9% to -6.3%) in the control group. No statistically significant between-group changes from baseline in cellular morphology were observed. Nine adverse events were possibly related to ECL, including 3 eyes with transient focal corneal edema and 4 eyes that required Micro-Stent trimming due to protrusion. CONCLUSIONS: In eyes with OAG, ECL after phacoemulsification is acute and stabilizes after 3 months, whereas ECL after phacoemulsification plus Micro-Stent implantation proceeds for at least 5 years. Clinical findings associated with ECL in these eyes were uncommon (3.3% of implanted eyes), suggesting that ECL is generally a subclinical phenomenon.

Safety and Effectiveness of CyPass Supraciliary Micro-Stent in Primary Open-Angle Glaucoma: 5-Year Results from the COMPASS XT Study.

PURPOSE: To characterize the long-term (up to 5 years) safety and effectiveness of the supraciliary Micro-Stent (Alcon) implanted at the time of phacoemulsification in eyes with coexisting open-angle glaucoma (OAG) and visually significant cataract. DESIGN: Three-year safety extension of a 2-year randomized clinical trial. METHODS: Patients from the multicenter Study of an Implantable Device for Lowering Intraocular Pressure in Glaucoma Patients Undergoing Cataract Surgery (COMPASS) trial who underwent Micro-Stent implantation plus phacoemulsification (n = 215) or phacoemulsification alone (n = 67) were evaluated 36, 48, and 60 months postoperatively. The primary outcome measurement was the occurrence of sight-threatening ocular adverse events. Evaluations at each time point included best-corrected visual acuity (BCVA), anterior and posterior segment examinations, tonometry, gonioscopy, pachymetry, perimetry, specular microscopy, and assessment of adverse events. RESULTS: Three sight-threatening ocular adverse events occurred, 2 in the Micro-Stent group and 1 in the control group, but none of these events was related to the Micro-Stent device. Ocular adverse events were of similar frequencies in both groups, the most common of which were BCVA loss of ≥2 lines compared with best BCVA in COMPASS and worsening of visual field mean defect (VFMD) ≥2.5 dB compared with month 24. Changes in mean BCVA from baseline, clinical examinations, pachymetry, and VFMD were similar in the 2 groups. At 60 months, a higher proportion of subjects in the Micro-Stent group (46%; 95% confidence interval [CI], 38.9%-53.2%) than in the control group (32.1%; 95% CI 19.9%-46.3%) were able to achieve a reduction of ≥20% in intraocular pressure without using hypotensive medication. CONCLUSIONS: Few sight-threatening serious ocular adverse events occurred following Micro-Stent implantation, and clinical evidence of corneal decompensation was minimal.

A large retrospective database analysis comparing outcomes of intraoperative aberrometry with conventional preoperative planning.

PURPOSE: To evaluate differences between the absolute prediction error using an intraoperative aberrometry (IA) device for intraocular lens (IOL) power determination versus the error that would have resulted if the surgeon's preoperative plan had been followed. SETTING: Multiple centers in the United States. DESIGN: Retrospective analysis of data collected using an IA device. METHODS: The database information was limited according to predetermined inclusion/exclusion criteria. Primary endpoints included the difference between mean and median absolute prediction error with IA use versus preoperative calculation, and the percentage of cases were compared when the prediction error was 0.5 diopters (D) or less. RESULTS: A total of 32 189 eyes were analyzed. The IA mean absolute prediction error was lower than the preoperative calculation, 0.30 D ± 0.26 (SD) versus 0.36 ± 0.32 D (P < .0001). The aberrometry absolute median prediction error was lower than the preoperative calculation, 0.24 D versus 0.29 D (P < .0001). There was a significantly greater percentage of eyes with an aberrometry absolute prediction error of 0.5 D or less than eyes with a preoperative absolute prediction error of 0.5 D or less (26 357 [81.9%] of 32 189 vs. 24 437 [75.9%] of 32 189, P < .0001). In addition, in those cases in which power of the IOL implanted was different than the preoperatively planned IOL power, significantly more eyes had an aberrometry absolute prediction error of 0.5 D or less (10 385 [81.3%] of 12 779 vs. 8794 [68.8%] of 12 779, P < .0001). CONCLUSIONS: In a database of more than 30 000 eyes, calculations incorporating IA outperformed preoperative calculations. The difference was more pronounced in those cases in which the preoperatively planned IOL power was different than the power of the IOL implanted.

Effect of age on survival between open repair and surveillance for small abdominal aortic aneurysms.

Randomized controlled trials have shown no significant difference in survival between immediate open repair and surveillance with selective repair for asymptomatic abdominal aortic aneurysms of 4.0 to 5.5 cm in diameter. This lack of difference has been shown to hold true for all diameters in this range, in men and women, but the question of whether patients of different ages might obtain different benefits has remained unanswered. Using the pooled patient-level data for the 2,226 patients randomized to immediate open repair or surveillance in the United Kingdom Small Aneurysm Trial (UKSAT; September 1, 1991, to July 31, 1998; follow-up 2.6 to 6.9 years) or the Aneurysm Detection and Management (ADAM) trial (August 1, 1992, to July 31, 2000; follow-up 3.5 to 8.0 years), the adjusted effect of age on survival in the 2 treatment groups was estimated using a generalized propensity approach, accounting for a comprehensive array of clinical and nonclinical risk factors. No significant difference in survival between immediate open repair and surveillance was observed for patients of any age, overall (p = 0.606) or in men (p = 0.371) or women separately (p = 0.167). In conclusion, survival did not differ significantly between immediate open repair and surveillance for patients of any age, overall or in men or women. Combined with the previous evidence regarding diameter, and the lack of benefit of immediate endovascular in trials comparing it with surveillance repair for small abdominal aortic aneurysms, these results suggest that surveillance should be the first-line management strategy of choice for asymptomatic abdominal aortic aneurysms of 4.0 to 5.5 cm.

Bayesian stopping guidelines for heart valve premarket approval studies.

OBJECTIVES: The Data Monitoring Committee (DMC) for the premarket approval (PMA) study of a new heart valve prosthesis convenes periodically to review the accumulating results of the study, and determines, among other things, whether there is enough concern with safety to stop the study. Their deliberations are largely subjective, based on their combined experience and expertise, but an objective aid to evaluating complication rates, usually called a stopping rule, is desirable. METHODS: The US Food and Drug Administration has designated objective performance criteria (OPC) for 7 heart valve complications. At the end of the PMA study, when approximately 800 patient-years have been accumulated, the complication rates must compare favorably with the OPC. Given the results to date at an interim review of the data, we use a Bayesian approach to compute the probability of passing the OPC test by the end of study. RESULTS: We provide a method that the DMC can use to predict the probability of passing the OPC test for each complication, and a graphical aid for each number of events, observed at 100 patient-year intervals. CONCLUSIONS: Although the DMC ultimately uses combined experience and expertise to make the decision to stop a PMA valve study, we have provided an objective assessment of the probability of the valve ultimately passing the OPC test to aid in making that decision.

Immediate open repair vs surveillance in patients with small abdominal aortic aneurysms: survival differences by aneurysm size.

OBJECTIVE: To assess whether survival differences exist between patients undergoing immediate open repair vs surveillance with selective repair for 4.0- to 5.4-cm abdominal aortic aneurysms (AAAs) and whether these differences vary by diameter, within sexes, or overall. PATIENTS AND METHODS: The study cohort included 2226 patients randomized to immediate repair or surveillance for the UK Small Aneurysm Trial (September 1, 1991, through July 31, 1998; follow-up, 2.6-6.9 years) or the Aneurysm Detection and Management trial (August 1, 1992, through July 31, 2000; follow-up, 3.5-8.0 years). Survival differences were assessed with proportional hazard models, adjusted for a comprehensive array of clinical and nonclinical risk factors. Interaction between treatment and AAA size was added to the model to assess whether the effect of immediate open repair vs surveillance varied by AAA size. RESULTS: The adjusted analysis revealed no statistically significant survival difference between immediate open repair and surveillance patients (hazard ratio [HR], 0.99; 95% CI, 0.83-1.18; mean follow-up time, 1921 days for both study groups). This lack of treatment effect persisted when men (HR, 1.01; 95% CI, 0.84-1.21) and women (HR, 0.96; 95% CI, 0.49-1.86) were examined separately and did not vary by AAA size (P=.39 for the entire cohort and P=.24 for women). CONCLUSION: Immediate open repair offered no significant survival benefit, even in patients with the largest AAAs and highest risk of rupture. Because recent trials failed to find a survival benefit of immediate endovascular repair over surveillance for small asymptomatic AAAs, our findings suggest that the gray area of first-line management for these patients should be resolved in favor of surveillance.

Established preoperative risk factors do not predict long-term survival in isolated coronary artery bypass grafting patients.

BACKGROUND: Use of isolated coronary artery bypass grafting (CABG) is expected to increase as the population ages. Short-term adverse outcomes models and their application to the decision-making process have greatly increased the safety and effectiveness of CABG. However, similar tools addressing long-term survival have not been developed. We examined the effect of the preoperative risk factors included in short-term outcomes models on long-term survival in patients who survive CABG. METHODS: A Cox survival model considering preoperative risk factors identified by The Society of Thoracic Surgeons was developed for 8,529 consecutive patients who underwent isolated CABG between January 1, 1997, and August 31, 2010, at Baylor University Medical Center (Dallas, Texas) and were alive 30-days post-CABG. RESULTS: There were 2,388 (27.9%) deaths during follow-up (≤14 years). Unadjusted survival was 83.8% and 65% at 5 and 10 years, respectively. The Cox model showed that most established preoperative risk factors were significantly associated with survival. Their effect was minimal, however; the variation explained by their cumulative effect in predicting survival was 16.8% (R2=0.168). CONCLUSIONS: Established operative risk factors may not be good predictors of long-term post-CABG survival. Late mortality may be attributable to many causes, not necessarily related to patients' cardiovascular and general health at the time of operation. Discussions with cardiothoracic surgeons and long-term shared decision making with primary care physicians/cardiologists should therefore not focus solely on patients' preoperative risk profile but should also emphasize the importance of preventing/controlling other diseases through a healthy lifestyle and compliance with disease management protocols.

Sequential design for clinical trials evaluating a prosthetic heart valve.

BACKGROUND: Clinical trials involving prosthetic heart valves are typically based on a set of objective performance criteria for certain late adverse event rates. Typically, these trials require 800 patient-years of data to be collected to provide 80% power while maintaining the type I error at the 0.05 level. METHODS: This work presents a sequential design alternative to the standard objective performance criteria trial that allows for the possibility of stopping the trial early. Logistical issues regarding these designs are considered, and power calculations are provided that investigate the probability of early stopping if the prosthetic valve exceeds expectations with respect to the objective performance criteria end points. RESULTS: Designs exist that provide at least 50% power at the interim look and 80% overall power under the alternative hypothesis. If the prosthetic valve performs better than expected, the interim power may exceed 80%. CONCLUSIONS: The proposed sequential designs can reduce the time required to bring a prosthetic heart valve to market, helping to ensure that patients and clinicians have access to the latest devices in shorter time.

Comparing long-term survival between patients undergoing off-pump and on-pump coronary artery bypass graft operations.

BACKGROUND: As the population of the United States and Western Europe ages, the number of patients undergoing isolated coronary artery bypass grafting (CABG) for revascularization can be expected to increase. This study investigated long-term survival in patients undergoing off-pump vs on-pump CABG. METHODS: Survival was assessed in 8081 consecutive patients who underwent isolated CABG (732 received off-pump) between January 1, 1997, and December 31, 2008. A propensity-adjusted model controlling for preoperative risk factors identified by the Society of Thoracic Surgeons and other preoperative clinical and nonclinical details was used to assess adjusted long-term mortality differences between off-pump and on-pump CABG. RESULTS: Ten-year unadjusted survival was 54.7% (95% confidence interval, 47.2% to 61.6%) in off-pump CABG patients and 62.3% (95% confidence interval 60.9% to 63.8%) in on-pump CABG patients. The log-rank test (p=0.012) indicated a significantly higher risk of death in off-pump CABG patients. After adjustment, the risk of death remained significantly higher in the off-pump CABG patients (hazard ratio, 1.18; 95% confidence interval, 1.02 to 1.38). The adjusted association regarding off-pump learning curve and survival was assessed separately and was not statistically significant (p=0.774), further validating our findings regarding off-pump CABG. CONCLUSIONS: After controlling for preoperative severity of disease and other possible confounders, the risk of long-term mortality in patients undergoing off-pump CABG is significantly higher than in those undergoing on-pump CABG. For multivessel coronary disease, on-pump CABG might be preferable to off-pump CABG given that it may achieve a more complete and durable revascularization.

New-onset postoperative atrial fibrillation and long-term survival after aortic valve replacement surgery.

BACKGROUND: Atrial fibrillation (AF) is recognized as a common complication of open cardiac surgery, occurring in up to 65% of patients. The advancing age and increasing risk profile of patients receiving aortic valve replacement (AVR) surgery is expected to raise incidence of new-onset postoperative AF resulting in potentially higher risk of adverse outcomes. In the early postoperative course, new-onset post-AVR AF is considered relatively easy to treat and is believed to have little impact on patients' long-term outcome. However, the effect of new-onset post-AVR AF on long-term survival is unclear. METHODS: Survival was assessed in 1,039 consecutive patients without preoperative AF who underwent AVR with or without simultaneous coronary artery bypass graft at Baylor University Medical Center, Dallas, Texas between January 1, 1997 and December 31, 2006. RESULTS: Ten-year unadjusted survival was 50.8% for patients with new-onset postoperative AF and 59.4% for patients without. A propensity-adjusted model controlling for risk factors identified by the Society of Thoracic Surgeons and other clinical-nonclinical details was used to investigate the association between new-onset AF post-AVR and survival. After adjustment, new-onset AF post-AVR was significantly associated with increased risk of death (hazard ratio: 1.48; 95% confidence interval 1.12 to 1.96). CONCLUSIONS: This study provides evidence that new-onset post-AVR AF is significantly associated with increased long-term risk of mortality independent of the preoperative severity of disease. After controlling for a comprehensive array of risk factors associated with post-AVR adverse outcomes, risk of long-term mortality in patients who developed new-onset post-AVR AF was 48% higher than in patients without it.

The importance of using the correct bounds on the Bland-Altman limits of agreement when multiple measurements are recorded per patient.

The limits of agreement originally derived by Bland and Altman (Lancet i:307-310, 1986) are the most commonly used method for investigating statistical agreement between two medical devices. Bland and Altman describe a confidence interval for these limits that should always accompany the limits themselves. However, this interval presumes that the recorded differences between the two devices in question are independent. This is a reasonable assumption when only one measurement is recorded per device per patient. Bland and Altman (StatMethods Med Res 8:135-160, 1999) subsequently derived bounds for the more general case where multiple observations are recorded within each patient. Unfortunately, in practice, the bounds assuming independence are typically reported when in fact the repeated measures bounds are more appropriate. This communication illustrates the dangers of using the "original" (independence-based) bounds derived in Bland and Altman (Lancet i:307-310, 1986) in the presence of repeated measures per patient.

New-onset postoperative atrial fibrillation after isolated coronary artery bypass graft surgery and long-term survival.

BACKGROUND: The advancing age and generally increasing risk profile of patients receiving isolated coronary artery bypass graft (CABG) surgery is expected to raise incidence of new-onset postoperative atrial fibrillation (AFIB) resulting in potentially higher risk of adverse outcomes. In the early postoperative course, new-onset post-CABG AFIB is considered relatively easy to treat and is believed to have little impact on patients' long-term outcome. However, little has been done to determine the effect of new-onset post-CABG AFIB on long-term survival, and this relationship is unclear. METHODS AND RESULTS: Survival was assessed in a cohort of 6899 consecutive patients without preoperative AFIB who underwent isolated CABG at Baylor University Medical Center, Dallas, Tex, between January 1, 1997 and December 31, 2006; patients who died during CABG were excluded. Ten-year unadjusted survival was 52.3% (48.4%, 56.0%) for patients with new-onset postoperative AFIB and 69.4% (67.3%, 71.4%) for patients without it. A propensity-adjusted model controlling for risk factors identified by the Society of Thoracic Surgeons and other clinical/nonclinical details was used to investigate the association between new-onset AFIB post-CABG and long-term survival. After adjustment, new-onset AFIB post-CABG was significantly associated (hazard ratio, 1.29; 95% CI, 1.16, 1.45) with increased risk of death. CONCLUSIONS: This study provides evidence that new-onset post-CABG AFIB is significantly associated with increased long-term risk of mortality independent of patient preoperative severity. After controlling for a comprehensive array of risk factors associated with post-CABG adverse outcomes, risk of long-term mortality in patients that developed new-onset post-CABG AFIB was 29% higher than in patients without it.

Using a prediction approach to assess agreement between two continuous measurements.

The problem of assessing agreement between two devices occurs with great frequency in the medical literature. If it can be demonstrated that a new device agrees sufficiently with a device currently in use, then the new device can be approved for general use. This work discusses how a prediction interval can be used to estimate the whether a future difference between two devices will be within acceptable limits with reasonable confidence. The method is illustrated with an example involving measurements of peak expiratory flow.

Taking patient mortalities into account when assessing change in NYHA classification from baseline.

Patient response to treatment is often monitored by comparing metrics of performance immediately before treatment and at follow up. One such metric in patients with heart disease is the New York Heart Association (NYHA) classification, which is graded on a I to IV scale. In order for such an analysis to be unbiased, any missing NYHA classifications at follow up must be 'missing completely at random'. The study aim was to determine how the exclusion of expired patient data may bias the analysis of changes in NYHA class, with attention focused on the effects of ignoring patient mortalities, not only for the sake of simplicity but also that this might inflict the largest degree of bias in favor of the treatment.

Relation of obesity to atrial fibrillation after isolated coronary artery bypass grafting.

The impact of obesity on risk of atrial fibrillation (AF) after coronary artery bypass grafting (CABG) is poorly understood. This study was performed to investigate the relation between body mass index (BMI; kilograms per square meter) or body surface area (BSA; square meters) and AF after CABG. Postoperative AF was assessed in a cohort of 7,027 consecutive patients without preoperative AF undergoing isolated CABG at Baylor University Medical Center from January 1, 1997 to December 31, 2006. Two propensity-adjusted models controlling for risk factors identified by the Society of Thoracic Surgeons and other clinical/nonclinical details were used. After adjustment, BMI and BSA (modeled using smoothing techniques to avoid categorization) were strongly associated (p <0.0001) with postoperative AF. Although evidence existed that gender was associated with AF (p <0.0001 and p = 0.1088 for BSA and BMI models, respectively), there was no indication that the effect of BMI or BSA on postoperative AF varied by gender. In conclusion, this study demonstrates that increased BMI and BSA are associated with a higher risk of AF after CABG and that risk for men is higher for the entire BSA spectrum and for extreme values of BMI.