Laparoscopic sleeve gastrectomy is an independent predictor of poor follow-up and reaching ≤ 40% excess body weight loss at 1, 2, and 3 years after bariatric surgery.

INTRODUCTION: Contrary to published literature, our institutional data demonstrated reduced weight loss following laparoscopic sleeve gastrectomy (LSG) compared to gastric bypass (LRYGB). The purpose of this study was to determine if known predictors of poor weight loss accounted for this discrepancy at a large volume center. METHODS: All patients undergoing primary LSG (n = 322) and LRYGB (n = 249), from 2014 to 2016, at a single institution were retrospectively reviewed. Baseline medical, socioeconomic, and follow-up data (6, 12, 24, and 36 months) were obtained. The first aim characterized differences in LSG and LRYGB. The second objective determined predictors of experiencing the lowest or highest quartile of excess body weight loss [(EBWL), (%EBWL-25th, %EBWL-75th)] at 12, 24, and 36 months. Thirdly, predictors of poor weight loss within sleeve gastrectomy were characterized. RESULTS: In comparison to patients undergoing LRYGB, LSG patients demonstrated lower baseline BMI (47.9 ± 8.2 vs. 51.5 ± 10.1, p < 0.0005), lower incidences of obesity-related comorbidities (p < 0.05), were more likely to have higher education (p = 0.02), and were associated with no-shows up to 2 years post-operatively. LSG remained a strong independent predictor of %EBWL-25th at 12 months (OR = 5.2, p < 0.005), 24 months (OR = 5.3, p < 0.005), and 36 months (OR = 7.3, p = 0.006), after adjusting for comorbidities, education, and no-shows. Predictors of poor weight loss after LSG included hypertension, African American race, major depression, no-shows at 6 and 12 months. Within patients associated with these characteristics, the relative risk of experiencing poor weight loss was significantly higher following LSG compared to LRYGB at 12 months (60% vs. 25.0%, p < 0.05), 24 months (43% vs. 18%, p < 0.05), and 36 months (70% vs. 21%, p < 0.05). CONCLUSIONS: LSG remained an independent predictor of poor weight loss at all post-operative time points. Furthermore, the risk of experiencing poor weight loss was significantly higher following LSG compared to LRYGB for patients with high-risk characteristics.

Baseline psychiatric diagnoses are associated with early readmissions and long hospital length of stay after bariatric surgery.

BACKGROUND: The impact of well-controlled or historical psychiatric diagnoses in patients seeking bariatric surgery (BS) on perioperative outcomes is unclear. The primary objective of this study was to determine the impact of psychiatric diagnoses on hospital length of stay (LOS), 30-day readmission rates after BS, and post-operative weight loss outcomes. METHODS: Patients who underwent laparoscopic sleeve gastrectomy (LSG) or Roux-en-Y gastric bypass (LRNYGB) from 2014 to 2016 at a single academic institution were retrospectively reviewed. Baseline demographic data and psychiatric history including depression, anxiety, and/or bipolar disorder (DAB) were obtained from the electronic medical record. Hospital LOS, 30-day readmissions, and % excess body weight loss (%EBWL) were obtained on all patients and compared between DAB patients and those without any psychiatric history. RESULTS: During the study period, 354 patients were reviewed, of which 78% were female; 60% underwent LSG. The mean preoperative BMI was 48.9 ± 8.4 m/kg2. Major depression was the leading diagnosis (42%), and 13% had both depression and anxiety. The 30-day readmission rate was significantly higher than the control (10.5% vs. 3.7%, p = 0.02). Mean hospital LOS and the incidence of long hospital LOS (≥ 4 days) was not different between the groups, although within LSG patients, the incidence of long hospital LOS trended towards being higher for DAB patients (9.2% vs. 4%, p = 0.10). Patients with depression and anxiety had a higher incidence of long LOS (23.4% vs. 9.2%, p < 0.005). While 6-month %EBWL was significantly lower for DAB patients (41% vs. 46%, p = 0.004), 1-year weight loss outcomes were not different, even when adjusting for surgical procedure. CONCLUSION: Patients with baseline or historical DAB had significantly higher early readmission rates, and those with multiple diagnoses were associated with a hospital LOS ≥ 4 days. Future studies should focus on elucidating the impact of psychiatric diagnoses on these quality metrics.

MRI Evaluation of Radiofrequency, Cryothermal, and Laser Left Atrial Lesion Formation in Patients with Atrial Fibrillation.

BACKGROUND:  Catheter ablation utilizing radiofrequency (RF), Cryothermal (Cryo), or Laser energy is effective for treatment of atrial fibrillation (AF). Late gadolinium enhancement magnetic resonance imaging (LGE-MRI) has been used to estimate the burden of left atrial (LA) fibrosis, but no data exist regarding structural changes following each modality. We sought to compare the baseline to postprocedure change in LA scar burden following RF, Cryo, or Laser ablation for treatment of AF. METHODS: Seventeen patients with AF underwent initial pulmonary vein (PV) isolation (PVI) using RF (n = 7), Cryo (n = 5), and Laser (n = 5). LGE-MRI was performed prior to and at 24 hours and 3 months after PVI. RESULTS: In a linear mixed-effects model, accounting for intrapatient clustering of data and interpatient differences in baseline scar, LGE extent was significantly increased at 24 hours postablation (+14.6 ± 1.9% of LA myocardium, P < 0.001), and remained stable from 24 hours to 3 months (+0.12 ± 1.9%, P = 0.951). There was no statistically significant difference between the postablation scar extent among ablation modalities when compared to RF (Cryo +4.5 ± 3.0%, P = 0.123; Laser -3.2 ± 3.0%, P = 0.291). The PV antral LGE intensity was increased by 25.1 ± 3.8% (P<0.001) 24 hours after ablation and additionally increased by 8.1 ± 3.8 at 3 months (P = 0.033). CONCLUSIONS: Radiofrequency, Cryo, and laser ablation result in increased LGE extent and intensity at 24 hours and 3 months postablation. No statistically significant difference was noted in the extent of fibrosis induced by any modality.

Phrenic nerve injury: An underrecognized and potentially preventable complication of pulmonary vein isolation using a wide-area circumferential ablation approach.

INTRODUCTION: Phrenic nerve injury (PNI) is a well-known, although uncommon, complication of pulmonary vein isolation (PVI) using radiofrequency energy. Currently, there is no consensus about how to avoid or minimize this injury. The purpose of this study was to determine how often the phrenic nerve, as identified using a high-output pacing, lies along the ablation trajectory of a wide-area circumferential lesion set. We also sought to determine if PVI can be achieved without phrenic nerve injury by modifying the ablation lesion set so as to avoid those areas where phrenic nerve capture (PNC) is observed. METHODS AND RESULTS: We prospectively enrolled 100 consecutive patients (age 61.7 ± 9.2 years old, 75 men) who underwent RF PVI using a wide-area circumferential ablation approach. A high-output (20 mA at 2 milliseconds) endocardial pacing protocol was performed around the right pulmonary veins and the carina where a usual ablation lesion set would be made. A total of 30% of patients had PNC and required modification of ablation lines. In the group of patients with PNC, the carina was the most common site of capture (85%) followed by anterior right superior pulmonary vein (RSPV) (70%) and anterior right inferior pulmonary vein (RIPV) (30%). A total of 25% of PNC group had capture in all 3 (RSPV, RIPV, and carina) regions. There was no difference in the clinical characteristics between the groups with and without PNC. RF PVI caused no PNI in either group. CONCLUSION: High output pacing around the right pulmonary veins and the carina reveals that the phrenic nerve lies along a wide-area circumferential ablation trajectory in 30% of patients. Modification of ablation lines to avoid these sites may prevent phrenic nerve injury during RF PVI.

Left Atrial LGE and Arrhythmia Recurrence Following Pulmonary Vein Isolation for Paroxysmal and Persistent AF.

OBJECTIVES: The aims of this study were to: 1) use a novel method of late gadolinium enhancement (LGE) quantification that uses normalized intensity measures to confirm the association between LGE extent and atrial fibrillation (AF) recurrence following ablation; and 2) examine the presence of interaction and effect modification between LGE and AF persistence. BACKGROUND: Recurrent AF after catheter ablation has been reported to associate with the baseline extent of left atrial LGE on cardiac magnetic resonance. Traditional methods for measurement of intensity lack an objective threshold for quantification and interpatient comparisons of LGE. METHODS: The cohort included 165 participants (mean age 60.0 ± 10.2 years, 77% men, 57% with persistent AF) who underwent initial AF ablation. The association of baseline LGE extent with AF recurrence was examined using multivariable Cox proportional hazards models. Multiplicative and additive interactions between AF type and LGE extent were examined. RESULTS: During 10.2 ± 5.7 months of follow-up, 63 patients (38.2%) experienced AF recurrence. Baseline LGE extent was independently associated with AF recurrence after adjusting for confounders (hazard ratio: 1.5 per 10% increased LGE; p < 0.001). The hazard ratio for AF recurrence progressively increased as a function of LGE. The magnitude of association between LGE >35% and AF recurrence was greater among patients with persistent AF (hazard ratio: 6.5 [p = 0.001] vs. 3.6 [p = 0.001]); however, there was no evidence for statistical interaction. CONCLUSIONS: Regardless of AF persistence at baseline, participants with LGE ≤35% have favorable outcomes, whereas those with LGE >35% have a higher rate of AF recurrence in the first year after ablation. These findings suggest a role for: 1) patient selection for AF ablation using LGE extent; and 2) substrate modification in addition to pulmonary vein isolation in patients with LGE extent exceeding 35% of left atrial myocardium.

Prevalence, Patterns, and Clinical Predictors of Left Ventricular Late Gadolinium Enhancement in Patients Undergoing Cardiac Magnetic Resonance Prior to Pulmonary Vein Antral Isolation for Atrial Fibrillation: A Cross-Sectional Observational Study.

Cardiac magnetic resonance (CMR) imaging is increasingly used to evaluate patients with atrial fibrillation (AF) before pulmonary vein antral isolation (PVAI). The purpose of this study was to assess the incidence and pattern of left ventricular (LV) late gadolinium enhancement (LGE) in patients undergoing CMR before PVAI and compare the clinical and demographic differences of patients with and without LV LGE. Clinical and demographic data on 62 patients (mean age 61 ±â€Š7.9, 69% male) undergoing CMR before PVAI for AF were collected. Two observers, masked to clinical histories, independently recorded the prevalence, extent (number of myocardial segments), and pattern (subendocardial, midmyocardial, or subepicardial) of LV LGE in each patient. Clinical and demographic predictors of LV LGE were determined using logistic regression. Twenty-three patients (37%) demonstrated LV LGE affecting a mean of 3.0 ±â€Š2.1 myocardial segments. There was no difference in LV ejection fraction between patients with and without LGE, and most (65%) patients with LGE had normal wall motion. Only age (P = 0.04) and a history of congestive heart failure (P = .03) were statistically significant independent predictors of LGE. The most common LGE pattern was midmyocardial, seen in 17 of 23 (74%) patients. Only 4 of 23 (17%) patients had LGE in an "expected" pattern based on clinical history. Of the remaining 19 patients, 4 had known congestive heart failure, 5 nonischemic cardiomyopathy, 4 known coronary artery disease, and 2 prior aortic valve replacement. Six of 23 (26%) patients had no known coronary artery, valvular, or myocardial disease. There is a high prevalence of unexpected LV scar in patients undergoing CMR before PVAI for AF, with most patients demonstrating a nonischemic pattern of LV LGE and no wall motion abnormalities (ie, subclinical disease). The high prevalence of unexpected LGE in these patients may argue for CMR as the modality of choice for imaging integration before PVAI, especially given the demonstrated prognostic value of LGE in this and other patient populations.

Magnetic resonance image intensity ratio, a normalized measure to enable interpatient comparability of left atrial fibrosis.

BACKGROUND: The measurement of late gadolinium-enhanced magnetic resonance imaging (LGE-MRI) intensity in arbitrary units limits the objectivity of thresholds for focal scar detection and interpatient comparisons of scar burden. OBJECTIVE: To develop and validate a normalized measure, the image intensity ratio (IIR), for the assessment of left atrial (LA) scar on LGE-MRI. METHODS: Electrocardiogram- and respiratory-gated 1.5 Tesla LGE-MRI was performed in 75 patients (75% men; 62 ± 8 years) before atrial fibrillation ablation. The local IIR was defined as LA myocardial signal intensity for each of the 20 sectors on contiguous axial image planes divided by the mean LA blood pool image intensity. Intracardiac point-by-point sampled electroanatomic map points were coregistered with the corresponding image sectors. RESULTS: The average bipolar voltage for all 8153 electroanatomic map points was 0.9 ± 1.1 mV. In a mixed effects model accounting for within patient clustering, and adjusting for age, LA volume, mass, body mass index, sex, CHA2DS2-VASc score, atrial fibrillation type, history of previous ablations, and contrast delay time, each unit increase in local IIR was associated with 91.3% decrease in bipolar LA voltage (P < .001). Local IIR thresholds of >0.97 and >1.61 corresponded to bipolar voltage <0.5 and <0.1 mV, respectively. CONCLUSIONS: Normalization of LGE-MRI intensity by the mean blood pool intensity results in a metric that is closely associated with intracardiac voltage as a surrogate of atrial fibrosis.

The association of pre-existing left atrial fibrosis with clinical variables in patients referred for catheter ablation of atrial fibrillation.

INTRODUCTION: Atrial fibrillation (AF) recurrence after ablation is associated with left atrial (LA) fibrosis on late gadolinium enhanced (LGE) magnetic resonance imaging (MRI). We sought to determine pre-ablation, clinical characteristics that associate with the extent of LA fibrosis in patients undergoing catheter ablation for AF. METHODS AND RESULTS: Consecutive patients presenting for catheter ablation of AF were enrolled and underwent LGE-MRI prior to initial AF ablation. The extent of fibrosis as a percentage of total LA myocardium was calculated in all patients prior to ablation. The cohort was divided into quartiles based on the percentage of fibrosis. Of 60 patients enrolled in the cohort, 13 had <5% fibrosis (Group 1), 15 had 5-7% fibrosis (Group 2), 17 had 8-13% fibrosis (Group 3), and 15 had 14-36% fibrosis (Group 4). The extent of LA fibrosis was positively associated with time in continuous AF, and the presence of persistent or longstanding persistent AF. However, no statistically significant difference was observed in the presence of comorbid conditions, age, BMI, LA volume, or family history of AF among the four groups. After adjusting for diabetes and hypertension in a multivariable linear regression model, paroxysmal AF remained independently and negatively associated with the extent of fibrosis (-4.0 ± 1.8, P = 0.034). CONCLUSION: The extent of LA fibrosis in patients undergoing AF ablation is associated with AF type and time in continuous AF. Our results suggest that the presence and duration of AF are primary determinants of increased atrial LGE.

Update on atrial fibrillation catheter ablation technologies and techniques.

Catheter ablation of atrial fibrillation (AF) has become an important treatment method. Electrical isolation of the pulmonary veins is the cornerstone of most AF ablation procedures, and is defined by an entrance block observed on a circular multipolar electrode catheter. The safety and efficacy of AF ablation is best established in middle-aged patients with paroxysmal AF. Current guidelines recommend AF ablation with a level Ia indication in this group of patients. The long-term efficacy of AF ablation is well established in patients with paroxysmal AF, but less so in patients with longstanding persistent AF. In this population, current guidelines recommend AF ablation with a level IIb indication. The efficacy of catheter ablation in other patient populations, particularly elderly people and those with concomitant conditions, is also poorly defined. AF ablation is reasonably effective and safe at 12 months of follow-up, but recurrence of AF ≥1 year after ablation is not uncommon. Fortunately, the techniques and tools used for AF ablation continue to evolve. These developments include novel ablation catheters designed to increase safety, efficacy, and precision of the procedure, ablation strategies to target both pulmonary vein and nonpulmonary vein AF triggers, and improved imaging and electrical mapping to guide ablation procedures.

Catheter Ablation of Atrial Fibrillation to Maintain Sinus Rhythm.

Catheter ablation of atrial fibrillation (AF) is an important treatment modality for patients with AF. Although the superiority of catheter ablation of AF over antiarrhythmic drug therapy has been demonstrated in middle aged patients with paroxysmal AF, the role of catheter ablation in other patient subgroups, particularly in the elderly, those with heart failure, and those with long standing persistent AF has not been as well defined. Furthermore, although AF ablation can be performed with reasonable efficacy and safety in experienced hands, late recurrences of AF a year or more following AF ablation are not uncommon. Fortunately the techniques and tools used for AF ablation continue to evolve and it is likely that the outcomes of AF ablation will improve further in the future.

Impact of Obstructive Sleep Apnea on Outcomes of Catheter Ablation of Atrial Fibrillation.

Obstructive sleep apnea (OSA) is a growing epidemic in the United States and significantly contributes to the increasing prevalence of atrial fibrillation (AF) in the U.S. POPULATION: Although a strong correlation between OSA and AF has been demonstrated, a causal relationship between these two conditions has not been definitively established. Evidence of OSA is an important consideration of AF management and impacts the success rate of catheter ablation. The presence of OSA tends to predict a lower success rate and higher complication rate for catheter ablation of AF. However, recent studies evaluating OSA as an independent risk predictor of AF recurrence following an ablation procedure have yielded conflicting results. A greater understanding of these conditions would allow for a more specific therapy targeting the type of AF associated with OSA. The following review provides a brief summary of obstructive sleep apnea etiology, focuses on the relationship between OSA and AF, and discusses the impact of OSA on the outcomes of catheter ablation of AF.

Safety and Efficacy of Atrial Fibrillation Ablation in Young Patients.

Background: Outcome of catheter ablation of atrial fibrillation (AF) in young patients has not been widely reported. This study describes the safety and efficacy of radiofrequency catheter ablation (RFA) for atrial fibrillation in patients forty years or younger. Methods and Results: Forty consecutive patients who underwent fifty-two RFA procedures for symptomatic, drug-refractory paroxysmal or non-paroxysmal AF were included in the study. The mean (SD) age of the patients at time of initial procedure was 34.1 (5.6) years. Twenty-five (62.5%) patients had paroxysmal AF, 6 (15%) patients had persistent AF, and 9 (22.5%) patients had longstanding persistent AF. Procedural safety and efficacy were assessed based on patient status > 1 year after initial ablation procedure. After a mean (SD) follow-up of 3.8 (2.9) years, 25 (62.5%) patients were free of AF without antiarrhythmic drugs (AAD) and 40 (100%) patients experienced > 95% reduction of AF burden on or off AADs. No major complications or adverse events occurred during the study. Conclusions: Catheter ablation of AF is a favorable therapeutic option for patients 40 years or younger, resulting in high rates of procedural success with a low risk of major complications.

Relationship between left atrial appendage morphology and stroke in patients with atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is an important cause of stroke. Given the morbidity and mortality associated with stroke, the risk stratification of patients based on left atrial appendage (LAA) characteristics is of great interest. OBJECTIVE: To explore the association between LAA morphology and LAA characteristics including the extent of trabeculations, orifice diameter, and length with prevalent stroke in a large cohort of patients with drug refractory AF who underwent AF ablation to develop mechanistic insight regarding the risk of stroke. METHODS: An institutional cohort of 1063 patients referred for AF ablation from 2003 to 2012 was reviewed to identify patients that underwent preprocedural cardiac computed tomography (CT). LAA morphology was characterized as chicken wing, cactus, windsock, or cauliflower by using previously reported methodology. Left atrial size and LAA trabeculations, morphology, orifice diameter, and length were compared between patients with prevalent stroke and patients without prevalent stroke. RESULTS: Of 678 patients with CT images, 65 (10%) had prior stroke or transient ischemic attack. In univariate analyses, prevalent heart failure (7.7% in cases vs 2.8% in controls; P = .033), smaller LAA orifice (2.26 ± 0.52 cm vs 2.78 ± 0.71 cm ; P < .001), shorter LAA length (5.06 ± 1.17 cm vs 5.61 ± 1.17 cm; P < .001), and extensive LAA trabeculations (27.7% vs 14.4%; P = .019) were associated with stroke. LAA morphologies were unassociated with stroke risk. In multivariable analysis, smaller LAA orifice diameter and extensive LAA trabeculations remained independently associated with thromboembolic events. CONCLUSIONS: The extent of LAA trabeculations and smaller LAA orifice diameter are associated with prevalent stroke and may mediate the previously described association of cauliflower LAA morphology with stroke.

State-of-the-art and emerging technologies for atrial fibrillation ablation.

Catheter ablation is an important treatment modality for patients with atrial fibrillation (AF). Although the superiority of catheter ablation over antiarrhythmic drug therapy has been demonstrated in middle-aged patients with paroxysmal AF, the role the procedure in other patient subgroups-particularly those with long-standing persistent AF-has not been well defined. Furthermore, although AF ablation can be performed with reasonable efficacy and safety by experienced operators, long-term success rates for single procedures are suboptimal. Fortunately, extensive ongoing research will improve our understanding of the mechanisms of AF, and considerable funds are being invested in developing new ablation technologies to improve patient outcomes. These technologies include ablation catheters designed to electrically isolate the pulmonary veins with improved safety, efficacy, and speed, catheters designed to deliver radiofrequency energy with improved precision, robotic systems to address the technological demands of the procedure, improved imaging and electrical mapping systems, and MRI-guided ablation strategies. The tools, technologies, and techniques that will ultimately stand the test of time and become the standard approach to AF ablation in the future remain unclear. However, technological advances are sure to result in the necessary improvements in the safety and efficacy of AF ablation procedures.