Five-year outcomes of endovascular repair of complicated acute type B aortic dissections.

OBJECTIVE: Thoracic endovascular aortic repair is the standard of care for acute complicated type B aortic dissections, but long-term single-device outcomes are limited. METHODS: Fifty patients were treated with the Valiant Captivia thoracic stent graft (Medtronic Inc, Santa Rosa, Calif) for acute complicated type B aortic dissections in this prospective, nonrandomized Dissection Trial. All-cause mortality, secondary procedures, and serious adverse events were assessed, and a core lab evaluated images for aortic remodeling. RESULTS: Compliance for both clinical and imaging follow-up was 78% (18 out of 23) for the available patients at 5 years. Notable baseline characteristics were 86% of patients (43 out of 50) had malperfusion, 20% (10 out of 50) had ruptures, and 94% (46 out of 49) had DeBakey class IIIB dissections. The 5-year freedom from dissection-related mortality, secondary procedures related to the dissection, and endoleaks was 83%, 86%, and 85%, respectively. After 5 years, 89% of patients (16 out of 18) had a completely thrombosed false lumen in the stented segment of the aorta and the true lumen diameter over the length of stent graft was stable or increased for 94% of patients (16 out of 17) while the false lumen diameter was stable or decreased in 77% (13 out of 17) after 5 years. CONCLUSIONS: In the Dissection Trial, patients experienced positive and sustained measures of aortic remodeling. Survival outcomes, need for secondary procedures, and adverse event rates were consistent with previous thoracic endovascular aortic repair studies. Although limitations exist with the follow-up compliance, the Valiant Captivia thoracic stent graft system was effective in the long-term management of acute complicated type B aortic dissections in this patient population with a challenging condition.

Successful Outcomes following Repair of a Type A Aortic Dissection during Pregnancy.

Type A aortic dissections during pregnancy are rare but lethal events, with reported mortalities as high as 60%. Unique changes in hemodynamics, hormone-related alterations in aortic tissue, and preexisting risk factors place patients at an elevated risk for dissection. We report a successful repair of a Type A aortic dissection at 32 weeks of gestation, with excellent outcomes in both mother and child. This report highlights the importance of gestational age and multidisciplinary effort.

Thoracic Endovascular Aortic Repair in Octogenarians and Nonagenarians.

BACKGROUND: The oldest segments of the population are expanding rapidly, and the number of thoracic endovascular aortic repairs (TEVARs) performed in the elderly parallels this trend. We describe our institutional TEVAR experience in octogenarians and nonagenarians. METHODS: All patients 80 years and older undergoing TEVAR at a single institution were reviewed using a prospectively maintained database. Baselines demographics, operative details, and outcomes were retrospectively analyzed. RESULTS: Twenty-five octogenarians and nonagenarians (age, 84.8 ± 3.7 years; 64% male) underwent TEVAR between January 2014 and January 2019. The most common preoperative comorbidities were hypertension (n = 24; 96%) and tobacco use (n = 18; 72%), and the mean modified frailty index was 0.32 ± 0.17. Degenerative aneurysms constituted the majority of aortic pathologies (60%), and most patients were symptomatic (64%), with a mean maximal aortic diameter of 62.7 ± 15.6 mm. Endoleaks were noted in 3 (12%) patients. Intensive care unit length of stay was 2.0 (1.5, 3.0) days, and the total length of stay was 5.0 (3.0, 7.0) days. In-hospital mortality was 12% (n = 3), while the overall 30-day mortality was 16% (n = 4). The median follow-up was 469.0 (76.0, 586.0) days. On univariate analysis, the presence of a postoperative complication was associated with a significantly increased risk of 30-day mortality (P < 0.01). CONCLUSIONS: Despite the inherently elevated operative risk among the elderly, this study demonstrates reasonable success rates for TEVAR in octogenarian and nonagenarian patients. In properly selected patients, advanced age alone should not be a prohibitive factor for TEVAR.

Use of a Dual-Filter Cerebral Embolic Protection Device in Thoracic Endovascular Aortic Repair.

BACKGROUND: The risk of periprocedural stroke after thoracic endovascular aortic repair (TEVAR) ranges from 3% to 8%. Although cerebral embolic protection devices (CEPD) are widely utilized in transcatheter aortic valve replacement, there are currently no Food and Drug Administration approved CEPDs for use in TEVAR. We report our initial experience with the off-label use of a dual-filter CEPD in patients undergoing TEVAR. METHODS: Two patients at high risk for embolic stroke underwent TEVAR for descending thoracic aortic aneurysms (DTAAs) at a single institution. A dual-filter CEPD (Sentinel; Boston Scientific, Marlborough, MA) was used in an off-label fashion in both cases. Patient 1 was a 62-year-old woman with a 6.2-cm DTAA, extending from the left subclavian artery (LSCA) to the diaphragm (Zones 3-5) and associated with extensive atherosclerotic disease of the aortic arch. Patient 2 was a 78-year-old woman with a 6.3-cm DTAA, extending from the LSCA (Zone 2) to the sixth intercostal space (Zone 4) with associated mural thrombus. Given the proximity of the aneurysm to the LSCA, a left carotid-subclavian bypass was performed for planned LSCA coverage. RESULTS: Through a percutaneous right radial artery approach using a 6F sheath, the Sentinel dual-filter CEPD was delivered over a 0.014″ guidewire into the thoracic aorta. Under fluoroscopic guidance, the 2 filters were sequentially deployed in the innominate and left common carotid arteries, respectively. Appropriately sized devices were successfully delivered and deployed in the proximal and distal landing zones, respectively. Two devices were used for each patient. Completion angiograms showed successful exclusion of the DTAAs in both cases, without evidence of endoleak. The CEPD filters were retrieved in standard fashion without difficulty. Pathology demonstrated successful capture of embolic debris and fibrin clot in both patients. Neither patient exhibited neurological deficits or device-related complications. Both patients remained neurologically intact at 1- and 2-month follow-up, respectively. Surveillance angiograms revealed successful exclusion of the aneurysm without any evidence of endoleak. CONCLUSIONS: We report the novel off-label use of a dual-filter CEPD in 2 patients undergoing TEVAR. Pathological confirmation of embolic debris in the filters makes this a potential tool for stroke prevention during TEVAR in high-risk patients.

Technique profile: mesenteric reconstructions for occlusive disease.

Visceral ischemic syndromes are rare but catastrophic disorders. In acute presentations, treatment modalities include thrombolytic therapy, open surgical revascularization and percutaneous endovascular therapy. Endovascular therapy has become the most commonly utilized treatment option for chronic mesenteric ischemia and should be considered the first line of therapy for patients with anatomically suitable lesions or excessive open surgical risk. Open surgical revascularization has been associated with outstanding long-term outcomes. The various surgical and endovascular techniques and their associated outcomes for the treatment of mesenteric ischemic syndromes are reviewed in detail.

A pilot study of a triple antimicrobial-bonded Dacron graft for the prevention of aortic graft infection.

OBJECTIVE: Perioperative infection of an aortic graft is one of the most devastating complications of vascular surgery, with a mortality rate of 10% to 30%. The rate of amputation of the lower limbs is generally >25%, depending on the graft material, the location of the graft and infection, and the bacterial virulence. In vitro studies suggest that an antibiotic-impregnated graft may help prevent perioperative graft infection. In a pilot animal study, we tested a locally developed technique of bonding Dacron aortic grafts with three antimicrobial agents to evaluate the ensuing synergistic preventive effect on direct perioperative bacterial contamination. METHODS: We surgically implanted a 6-mm vascular knitted Dacron graft in the infrarenal abdominal aorta of six Sinclair miniature pigs. Two pigs received unbonded, uninoculated grafts; two received unbonded, inoculated grafts; and two received inoculated grafts that were bonded with chlorhexidine, rifampin, and minocycline. Before implantation, the two bonded grafts and the two unbonded grafts were immersed for 15 minutes in a 2-mL bacterial solution containing 1 to 2 × 10(7) colony-forming units (CFU)/mL of Staphylococcus aureus (ATCC 29213). Two weeks after graft implantation, the pigs were euthanized, and the grafts were surgically excised for clinical, microbiologic, and histopathologic study. RESULTS: The two bonded grafts treated with S aureus showed no bacterial growth upon explant, whereas the two unbonded grafts treated with S aureus had high bacterial counts (6.25 × 10(6) and 1.38 × 10(7) CFU/graft). The two control grafts (unbonded and untreated) showed bacterial growth (1.8 × 10(3) and 7.27 × 10(3) CFU/graft) that presumably reflected direct, accidental perioperative bacterial contamination; S cohnii ssp urealyticus and S chromogenes, but not S aureus, were isolated. The histopathologic and clinical data confirmed the microbiologic findings. Only pigs that received unbonded grafts showed histopathologic evidence of a perigraft abscess. CONCLUSIONS: Our results suggest that bonding aortic grafts with this triple antimicrobial combination is a promising method of reducing graft infection resulting from direct postoperative bacterial contamination for at least 2 weeks. Further studies are needed to explore the ability of this novel graft to combat one of the most feared complications in vascular surgery.

Endovascular treatment of hemodialysis access pseudoaneurysms.

OBJECTIVE: Pseudoaneurysm (PSA) formation is a complication of hemodialysis access. Open repair requires PSA resection, interposition graft placement, and insertion of a catheter as a bridge. Endovascular stent graft repair is an alternative that permits immediate use of the access site. The objective of this study was to determine the efficacy of stent grafts for repair of arteriovenous fistula and arteriovenous graft PSA. METHODS: A retrospective review of medical records from October 2007 to March 2011 revealed 24 patients with a PSA who underwent endovascular repair using a stent graft. Indications for repair included PSA with symptoms (n = 11), PSA with skin erosion (n = 8), PSA with failed hemodialysis (n = 3), and PSA after balloon angioplasty of a stenosis (n = 2). Outcome measures were technical success, 30-day and 180-day patency, secondary interventions, and complications. All the statistical analyses were conducted by using software SAS 9.1 (SAS, SAS Institute, Gary, NC). RESULTS: Twenty-seven self-expanding stent grafts (Viabahn, W. L. Gore, n = 25; Fluency, Bard, n = 2) were used to treat hemodialysis access (arteriovenous graft, n = 13; arteriovenous fistula, n = 11) PSA in 24 patients (16 females; mean age, 55.7 years; mean body mass index, 28.4; mean PSA diameter, 19.5 mm). Comorbidities included hypertension (n = 22; 91.7%), diabetes mellitus (n = 8; 33.3%), and coronary artery disease (n = 4; 16.67%). The median time from access creation to repair was 455 days. The technical success rate was 100%. Balloon angioplasty of an outflow stenosis was performed in 56% of stent grafts. The 30- and 180-day patency rate was 100% and 69.2%, respectively. Three secondary interventions were performed for treatment of unrelated stenosis. Treatment failure occurred in five (18.5%) stent grafts due to infection (n = 3) and thrombosis (n = 2). Treatment of PSA with skin erosion was associated with failure due to infection (odds ratio, 5.0; 95% confidence interval, .38, 66.01). The remaining 22 (81.5%) stent grafts remain patent. The mean follow-up time was 268.9 days (median, 97.5). CONCLUSIONS: Endovascular therapy is an effective and durable treatment option for patients with dialysis access PSAs. This technique permits immediate use of the hemodialysis access site as well as identification and treatment of associated stenosis. It may be considered as an alternative to open repair in patients who are anatomically suitable candidates.

Late outcomes after radial artery versus saphenous vein grafting during reoperative coronary artery bypass surgery.

OBJECTIVE: We investigated whether use of radial artery versus saphenous vein grafts during coronary artery bypass grafting reoperations is associated with a significant long-term survival benefit. METHODS: We reviewed a series of 347 consecutive coronary artery bypass grafting reoperations (1996-2007; 270 [78%] male patients; age, 65.3 +/- 9.2 years). Internal thoracic artery grafts were used in 248 (71%) patients at the time of the first coronary artery bypass grafting operation and in 154 (44%) patients at reoperation. Patients were grouped based on whether a functional radial artery graft was present after coronary artery bypass grafting reoperation (radial artery cohort, n = 203 [59%]) or not (saphenous vein cohort, n = 144 [41%]). Median time to reoperation was similar for the radial artery (10.3 years) and saphenous vein (10.1 years) cohorts (P = .55). Angiographic data were used to ascertain the number and type of grafts that remained functional from initial coronary artery bypass grafting. Survival data (< or = 12 years) were time segmented based on multiphase hazard modeling at 90 days, and late survival was then analyzed by using proportional hazard Cox regression, with risk adjustment based on a radial artery-use propensity score computed from 48 covariates, including time to reoperation, month of surgical intervention, and total arterial and vein grafts after reoperation. Propensity-matched and propensity quintile comparisons were also done. RESULTS: Follow-up was similar for the radial artery versus saphenous vein cohorts (5.7 +/- 3.4 vs 5.8 +/- 4.0 years, P = .86), and 112 (50 in the radial artery and 62 in the saphenous vein cohorts) deaths were documented. Early mortality (< or = 90 days) did not differ for the radial artery (7.4%) and saphenous vein (12.5%) cohorts (P = .14). Unadjusted late outcomes were superior for the radial artery versus saphenous vein cohorts, with survival of 97.3% versus 92.9%, 84.9% versus 77.2%, and 74.1% versus 60.3% at 1, 5, and 10 years, respectively. Propensity-adjusted radial artery survival was superior, with a hazard ratio of 0.58 (P = .04), and this result was confirmed in a propensity-matched comparison. CONCLUSIONS: We conclude that the use of radial artery as opposed to saphenous vein grafting for reoperative coronary artery bypass grafting, either with or without concomitant internal thoracic artery grafts, is associated with a substantial improvement in late survival. This benefit is likely derived from the increased overall number of arterial grafts.

Sequential radial artery grafts for multivessel coronary artery bypass graft surgery: 10-year survival and angiography results.

BACKGROUND: Increasing the number of arterial grafts for coronary artery bypass grafting (CABG) has been linked to improved late survival. Currently, it is not known if these long-term benefits are also true when sequential radial artery (RA) grafts are the primary means to maximizing arterial revascularization. METHODS: We compared late survival of 532 consecutive patients receiving sequential RA grafts (sequential RA group: 438 men; 462 with three-vessel disease) with that of a 4,131 contemporaneous internal thoracic artery (ITA) with saphenous vein (SV) multivessel CABG cohort (conventional group). Graft failure rates were determined from symptom-driven repeat angiography films in 122 sequential RA patients performed 2 to 4,317 days after surgery. Median survival sequential RA follow-up was 5.3 years (range, 0.5 to 12.3). RESULTS: The sequential RA patients received a total of 1,181 RA grafts (538 sequential [30 triple] and 75 single) along with 636 SV and 533 ITA. Overall RA graft failure (80 of 272; 29%) was intermediate to that for ITA (7 of 121; 5.8%; p < 0.001) and vein (54 of 133, 41.6%; p = 0.032) grafts. Sequential versus nonsequential RA failure did not differ (77 of 252 [31%] versus 3 of 20 [15%]; p = 0.202), while failure of the proximal (36 of 123; 29%) and distal (40 of 129; 31%) components of sequential RA grafts were essentially identical. A total of 69 deaths (6 operative; 1.1%) have occurred in the sequential RA cohort. Unadjusted 10-year sequential RA cohort survival was 76.2% overall, and 79.0% for the 454 primary isolated CABG subgroup. The risk-adjusted 10-year survival using a logit propensity score was substantially better for the sequential RA cohort versus the conventional CABG cohort (risk ratio [95% confidence interval] 0.61 [0.44 to 0.85]; p = 0.003). CONCLUSIONS: Sequential RA grafting is a safe method for maximizing arterial revascularization and is associated with excellent 10-year survival that seems to be superior to conventional or ITA/SV CABG results. Also, the similar proximal and distal sequential RA patency mitigates concerns of a clinically significant effect of increased vasoreactivity of distal segments of RA conduits.

Late results of conventional versus all-arterial revascularization based on internal thoracic and radial artery grafting.

BACKGROUND: Use of one or more arterial grafts to revascularize two-vessel and three-vessel coronary artery disease has been shown to improve coronary artery bypass graft surgery (CABG) survival. Yet, the presumed long-term survival benefits of all-arterial CABG have not been quantified. METHODS: We compared propensity-adjusted 12-year survival in two contemporaneous multivessel primary CABG cohorts with all patients receiving 2 or more grafts: (1) all-arterial cohort (n = 612; 297 three-vessel disease [49%]); and (2) single internal thoracic artery (ITA) plus saphenous vein (SV) cohort (n = 4,131; 3,187 three-vessel disease [77%]). RESULTS: Early (30-day) deaths were similar for the all-arterial and ITA/SV cohorts (8 [1.30%] versus 69 [1.67%]) whereas late mortality was substantially greater for the ITA/SV cohort (85 [13.9%] versus 1,216 [29.4%]; p < 0.0001). The risk-adjusted 12-year survival was significantly better for all-arterial (with a risk ratio [RR] = 0.60; 95% confidence interval [CI]: 0.48 to 0.75; p < 0.001), but this benefit was true only for three-vessel disease (RR = 0.58; 95% CI: 0.43 to 0.78; p < 0.001) and not for two-vessel disease (RR = 0.97; 95% CI: 0.66 to 1.43; p = 0.89). The all-arterial survival benefit was also true for varying risk subcohorts: no diabetes mellitus (RR = 0.50; 95% CI: 0.37 to 0.69), diabetes mellitus (RR = 0.77; 95% CI: 0.56 to 1.07), ejection fraction 40% or greater (RR = 0.60; 95% CI: 0.45 to 0.78), and ejection fraction less than 40% (RR = 0.62; 95% CI: 0.40 to 0.98). Lastly, the multivariate analysis indicated a strong long-term effect of completeness of revascularization, particularly for all-arterial patients, so that compared with patients with two grafts, survival was significantly better when three grafts (RR = 0.54; 95% CI: 0.33 to 0.87) or four grafts (RR = 0.40; 95% CI: 0.21 to 0.76) were completed. CONCLUSIONS: All-arterial revascularization is associated with significantly better 12-year survival compared with the standard single ITA with saphenous vein CABG operation, in particular for triple-vessel disease patients. The completeness of revascularization of the underlying coronary disease is critical for maximizing the long-term benefits of arterial-only grafting.

Does radial use as a second arterial conduit for coronary artery bypass grafting improve long-term outcomes in diabetics?

OBJECTIVES: The evidence supporting the survival benefit of multiple arterial grafts in the general coronary bypass surgery (CABG) population is compelling. Alternatively, results of studies comparing 2 versus 1 internal thoracic artery (ITA) grafts in diabetics have reported conflicting survival data. The use of radial versus ITA as the second arterial conduit has not been studied. METHODS: We obtained complete death follow-up in 1516 consecutive diabetic [64+/-10 years (mean+/-SD). Insulin/no insulin: There were 540 (36%)/976 (64%)] primary isolated CABG patients all with >or=1 ITA grafts. The series included 626 ITA/radial (41%) and 890 ITA/vein (59%) patients. Using separate radial-use propensity models, we matched one-to-one 475 (76%) ITA/radial to 475 (53%) unique ITA/vein patients; each including 166 insulin and 309 no insulin patients. RESULTS: Unadjusted survival was markedly better for (1) ITA/radial (94.3%, 86.7% and 70.4% at 1, 5 and 10 years, respectively) versus ITA/vein (91.8%, 74.5% and 53.8%; p<0.0001) and (2) for no insulin (94.2%, 82.8% and 65.5%) versus insulin (90.4%, 73.1% and 49.2%; p<0.0001). In matched patients, 11-year Kaplan-Meier analysis showed essentially identical ITA/radial and ITA/vein survival for all diabetics combined (p=0.53; log rank) and for the no insulin (p=0.76) cohort. Lastly, a trend for better ITA/radial survival in insulin dependent diabetics after the second postoperative year did not reach significance (p=0.13). CONCLUSIONS: Using radial as a second arterial conduit as opposed to vein grafting did not confer a survival benefit in diabetics. This unexpected result is perhaps related to relatively diminished radial graft patency and/or the augmented radial vasoreactivity characteristic of diabetics. These findings indicate that the radial survival advantage demonstrated in the general CABG population lies primarily in non-diabetics in whom this advantage may be underestimated.

Survival and graft patency after coronary artery bypass grafting with coronary endarterectomy: role of arterial versus vein conduits.

BACKGROUND: Coronary artery bypass grafting with concomitant coronary endarterectomy (CABG/CE) is used in patients with severe coronary atherosclerosis to revascularize otherwise ungraftable targets. This study investigates the efficacy of arterial versus vein grafting for CABG/CE surgery. METHODS: We reviewed our experience in 288 CABG/CE patients (63 +/- 10 years, 207 men). A total of 1,056 grafts (275 internal thoracic artery [ITA] [26%]; 221 radial [21%], 560 vein [53%]) were constructed including 325 (31%) placed to CE targets. RESULTS: Eighteen of 288 patients died in-hospital (6.3%). Unadjusted one-year and five-year survival for the 270 discharged patients was 95.2% and 83.0%, respectively. Survival (0 to 7 years) was significantly better for patients with radial (n = 154) versus no-radial (n = 134) artery grafting (p = 0.021). Multivariate Cox regression analysis associated increased number of arterial grafts (hazard ratio [HR] = 0.64 [0.44 to 0.92]; HR [95% confidence interval]) to improved survival, while RCA endarterectomy (HR = 1.8 1.0 3.3; p = 0.054) was associated with worse survival. Repeat angiography (495 days [median]) in 68 patients encompassed 78 CE (38 vein, 24 ITA, and 16 radial) and 162 non-CE (84 vein, 40 ITA, and 38 radial) grafts. Graft failure was similar (p = 0.37) for radial (10 of 54 [19%]) and ITA (7 of 64 [11%]), and worst for vein (50 of 122 [41%]; p < 0.001). For CE targets, graft failure was worse for vein (55% vs 35%; p = 0.05) and unchanged for arterial (13% vs 15%; p = 0.88) grafts. CONCLUSIONS: Combined CABG/CE is associated with good long-term outcomes. Increased arterial grafting achieved by radial artery utilization confers a survival benefit in this high-risk population. The latter is probably derived from superior radial versus vein graft patency.

Obesity and risk of new-onset atrial fibrillation after cardiac surgery.

BACKGROUND: New-onset postoperative atrial fibrillation (AF) is a common complication of cardiac surgery that has substantial effects on outcomes. In the general (nonsurgical) adult population, AF has been linked to increasing obesity, which correlates with left atrial enlargement. It is not known whether postoperative AF is similarly linked to obesity. METHODS AND RESULTS: This was a retrospective analysis of the incidence of AF in terms of body mass index (BMI). A total of 8051 consecutive cardiac surgery patients (1994 to 2004; mean age 64 [SD 11] years; 5372 men [67%]) who were free of any history of preoperative AF or flutter were included in the analysis. This series included 3164 obese patients (39%; median age 62 years) and 4887 nonobese patients (61%; median age 66 years), who were further divided on the basis of BMI (kg/m2) into 6 groups: BMI <22 kg/m2, 22< or =BMI< or =25 kg/m2 (normal), 25 or =30 kg/m2 (overweight), 30 or =35 kg/m2 (obese I), 35 or =40 kg/m2 (obese II), and BMI >40 kg/m2 (obese III). Unadjusted AF incidence was similar in obese and nonobese patients (n=742 [23.5%] versus n=1068 [21.9%], respectively; P=0.099). Covariate-adjusted ORs for AF were systematically greater for larger patients than for patients in the normal group (adjusted OR [95% CI]=1.18 [1.00 to 1.40], 1.36 [1.14 to 1.63], 1.69 [1.35 to 2.11], and 2.39 [1.81 to 3.17] for overweight, obese I, obese II, and obese III, respectively). Other AF predictors included age (adjusted OR=1.52 [95% CI 1.46 to 1.58] per 10 years), mitral valve surgery (adjusted OR=2.42 [95% CI 1.92 to 3.06]), aortic valve surgery (adjusted OR=1.79 [95% CI 1.45 to 2.22]), chronic obstructive pulmonary disease (adjusted OR=1.28 [95% CI 1.12 to 1.46]), male gender (adjusted OR=1.24 [95% CI 1.10 to 1.40]), preoperative beta-blocker use (adjusted OR=1.17 [95% CI 1.05 to 1.32]), vascular disease (adjusted OR=1.18 [95% CI 1.05 to 1.32]), white race (adjusted OR=1.33 [95% CI 1.07 to 1.66]), history of arrhythmia other than AF/flutter (adjusted OR=0.80 [95% CI 0.68 to 0.96]), ejection fraction <40% (adjusted OR=1.16 [95% CI 1.03 to 1.31]), left main disease (adjusted OR=1.15 [95% CI 1.00 to 1.32]), and off-pump surgery (adjusted OR=0.61 [95% CI 0.44 to 0.83]). The obesity-AF association was confirmed in 4 1-to-1 propensity-matched obese versus nonobese comparisons and in 2 separate derivation/validation subcohort analyses. CONCLUSIONS: Obesity is an important determinant of new-onset AF after cardiac surgery. Future postoperative AF risk models should incorporate BMI or obesity levels. Studies examining the efficacy of AF-minimizing prophylactic interventions in high-BMI patients, particularly in the elderly, may be warranted.