Robotic-assisted cryothermic Cox maze for persistent atrial fibrillation: Longitudinal follow-up.

OBJECTIVES: Surgical ablation of atrial fibrillation (AF) is recommended as a stand-alone therapy for patients refractory to medical or catheter-based treatment, or as a concomitant therapy when associated with structural disease. We report a single-therapy robotic approach to the Cox maze with longitudinal follow-up. METHODS: Consecutive patients who underwent robotic biatrial cryothermic Cox maze for nonparoxysmal AF between November 2016 and January 2022 were examined at 1, 2, 3, 6, 9, 12, 18, 24, 36, 48, and 60 months. Freedom from atrial tachyarrhythmia was assessed with 24-hour continuous electrocardiogram or pacemaker interrogation in all patients after 6 months. Mean follow-up was 17 ± 14.5 months (range, 1-60 months). Time to event analysis with competing risks was used to determine risk-adjusted associations with late outcomes. RESULTS: Patients (n = 135) had a median AF duration of 4.0 years (interquartile range, 0.8-7.0), with 29.6% in whom 1 or more catheter ablations had failed. Stand-alone maze was performed in 25.2%, whereas 61.4% underwent concomitant robotic mitral valve surgery, 7.4% tricuspid valve repair, and 4.4% aortic valve replacement. No patients were discharged in AF. There were 3 operative mortalities (2.2%), none in stand-alone patients. One patient required catheter ablation at 8 months postoperatively, and one had a nonembolic stroke at 18 months. There were 9 late deaths. Freedom from atrial tachyarrhythmia and antiarrhythmic drugs at 9, 12, 18, 24, 36, and 48 months was 97.0%, 96.7%, 98.1%, 97.1%, and 100%, respectively. Lower ejection fraction and need for concomitant mitral valve replacement and/or aortic valve replacement were independently associated with worse survival. CONCLUSIONS: For persistent AF, robotic biatrial cryothermic Cox maze offered greater than 90% 1-year longitudinal freedom from stroke, oral anticoagulation, repeat ablation, and recurrent AF without the need for antiarrhythmic drugs.

The hypothalamic RFamide, QRFP, increases feeding and locomotor activity: The role of Gpr103 and orexin receptors.

Here we show that central administration of pyroglutamylated arginine-phenylamine-amide peptide (QRFP/26RFa) increases both food intake and locomotor activity, without any significant effect on energy expenditure, thermogenesis or reward. Germline knock out of either of the mouse QRFP receptor orthologs, Gpr103a and Gpr103b, did not produce a metabolic phenotype. However, both receptors are required for the effect of centrally administered QRFP to increase feeding and locomotor activity. As central injection of QRFP activated orexin/hypocretin neurons in the lateral hypothalamus, we compared the action of QRFP and orexin on behaviour. Both peptides increased arousal and locomotor activity. However, while orexin increased consummatory behaviour, QRFP also affected other appetitive behaviours. Furthermore, the feeding but not the locomotor response to QRFP, was blocked by co-administration of an orexin receptor 1 antagonist. These results suggest that QRFP agonism induces both appetitive and consummatory behaviour, but only the latter is dependent on orexin/hypocretin receptor signalling.

Manipulation of the miR-378a/mt-ATP6 regulatory axis rescues ATP synthase in the diabetic heart and offers a novel role for lncRNA Kcnq1ot1.

Diabetes mellitus has been linked to an increase in mitochondrial microRNA-378a (miR-378a) content. Enhanced miR-378a content has been associated with a reduction in mitochondrial genome-encoded mt-ATP6 abundance, supporting the hypothesis that miR-378a inhibition may be a therapeutic option for maintaining ATP synthase functionality during diabetes mellitus. Evidence also suggests that long noncoding RNAs (lncRNAs), including lncRNA potassium voltage-gated channel subfamily Q member 1 overlapping transcript 1 (Kcnq1ot1), participate in regulatory axes with microRNAs (miRs). Prediction analyses indicate that Kcnq1ot1 has the potential to bind miR-378a. This study aimed to determine if loss of miR-378a in a genetic mouse model could ameliorate cardiac dysfunction in type 2 diabetes mellitus (T2DM) and to ascertain whether Kcnq1ot1 interacts with miR-378a to impact ATP synthase functionality by preserving mt-ATP6 levels. MiR-378a was significantly higher in patients with T2DM and 25-wk-old Db/Db mouse mitochondria, whereas mt-ATP6 and Kcnq1ot1 levels were significantly reduced when compared with controls. Twenty-five-week-old miR-378a knockout Db/Db mice displayed preserved mt-ATP6 and ATP synthase protein content, ATP synthase activity, and preserved cardiac function, implicating miR-378a as a potential therapeutic target in T2DM. Assessments following overexpression of the 500-bp Kcnq1ot1 fragment in established mouse cardiomyocyte cell line (HL-1) cardiomyocytes overexpressing miR-378a revealed that Kcnq1ot1 may bind and significantly reduce miR-378a levels, and rescue mt-ATP6 and ATP synthase protein content. Together, these data suggest that Kcnq1ot1 and miR-378a may act as constituents in an axis that regulates mt-ATP6 content, and that manipulation of this axis may provide benefit to ATP synthase functionality in type 2 diabetic heart.

Robotic Aortic Valve Replacement: First 50 Cases.

BACKGROUND: Existing management challenges in selecting transcatheter vs surgical aortic valve replacement (SAVR) include bicuspid stenosis, low clinical risk, horizontal valve position, aortic insufficiency (AI), and need for concomitant procedures or mechanical valves. To address these gaps, we present our early experience with fully robotic-assisted aortic valve replacement (RAVR). METHODS: Between January 2020 and February 2021, 50 consecutive RAVR operations were performed using a 3- to 4-cm lateral mini-thoracotomy 3-port technique with transthoracic aortic clamping, similar to our robotic mitral platform. Conventional SAVR prostheses were implanted with interrupted braided sutures in all cases. RESULTS: The 50 patients were a median age of 67.5 years, body mass index was 29 kg/m2, calcified bicuspid disease was present in 28 (56%), and severe AI in 8 (16%). Ejection fraction was 0.55 ± 0.08 (mean ± SD), and The Society of Thoracic Surgeons predicted risk of mortality was 1.54% ± 0.7%. Mechanical prostheses were used in 16 of 50 (32%), and 7 required concomitant procedures, including Cox maze in 3, aortic root enlargement in 2, and left atrial appendage clipping, mitral repair, and left atrial myxoma excision in 1 each. Median times (minutes) were 166 for cardiopulmonary bypass, 117 for cross-clamp, 4 for valvectomy, 20 for annular sutures, and 31 for aortotomy closure. All times plateaued after the initial 5 cases. Extubation occurred in 42 of 50 patients (84%) in the operating room, and within 4 hours in the remaining 8 (16%). There was no 30-day operative mortality or stroke. All had 30-day echocardiography demonstrating no valvular or perivalvular abnormalities. CONCLUSIONS: RAVR appears to have procedural safety and short-term outcomes to rival alternatives. Incremental experience may facilitate the safe performance of concomitant procedures as deemed necessary.

Robotic assisted cryothermic biatrial Cox-Maze.

INTRODUCTION: Robotic cryothermic Cox-Maze (CM) IV is a minimally invasive procedure that reliably replicates the biatrial lesion set of the CM III by utilizing cryothermia as a single power source. METHODS: Herein we describe a step by step creation of the biatrial CM III lesion sets utilizing the minimally invasive robotic platform. RESULTS: Technical details are reviewed for this single incision, single stage, highly effective option for stand-alone or concomitant surgical ablation of atrial fibrillation (AF). CONCLUSION: Robotic cryothermic CM IV can be safely performed as a stand-alone or concomitant procedure, and offers a comprehensive surgical ablation solution for patients with AF.

Incidence, Predictors, and Outcomes of Early Acute Myocardial Infarction Following Coronary Artery Bypass Grafting.

Large-scale data on early postdischarge acute myocardial infarction (AMI) after coronary artery bypass grafting (CABG) are lacking. We queried the National Readmission Database (2015 to 2016) to identify patients who underwent CABG between January 1 and June 31 (i.e., had 6 months of follow-up). The study's end points were the incidence, predictors, and outcomes of early post-CABG AMI. Of the 203,760 included patients, 3,829 (1.8%) were readmitted for AMI. Compared with patients without readmissions for AMI, those with AMI were younger (65 ± 11 vs 66 ± 10 years), had more females (35.5% vs 25.1%), and higher prevalence of hypertension, diabetes, obstructive lung disease, anemia, vascular disease, renal insufficiency, and liver cirrhosis, but less atrial fibrillation (p <0.001). They also had a distinctive profile of their index CABG surgery. The strongest predictors of post-CABG AMI readmission were female gender (odds ratio [OR] 1.46, 95% confidence interval [CI] = 1.36 to 1.57), heart failure (OR 1.37, 95% CI = 1.27 to 1.50), dialysis (OR 1.5%, 95% CI = 1.25 to 1.78), cirrhosis (OR 1.61, 95% CI = 1.14 to 2.27), nonelective CABG (OR 1.70, 95% CI = 1.57 to 1.84), perioperative mechanical circulatory support (OR 1.37, 95% CI = 1.23 to 1.51), low-volume centers (OR 1.36, 95% CI = 1.18 to 1.56), and nonhome discharge after CABG (OR 1.47, 95% CI = 1.35 to 1.59). In the patients who were readmitted for AMI, 86.3% had non-ST-elevation AMI and 13.7% had ST-elevation AMI. Coronary angiography was performed in 2,096 patients (54.7%). Of those, 63.5% received percutaneous coronary intervention, and 1.7% had redo-CABG. Readmissions for AMI were associated with significant in-hospital mortality (5.7%), acute kidney injury (22.1%), and new dialysis (2.1%). Median length-of-stay was 3 days (25th/75th percentile 2,6), and the mean hospital cost was $22,207 ± 29,071.

Association between surgical volume and clinical outcomes following coronary artery bypass grafting in contemporary practice.

BACKGROUND: Studies assessing the association between surgical volume and coronary artery bypass grafting (CABG) outcomes yielded conflicting results. Given the substantial recent decrease in CABG volume, we sough to examine the volume-outcomes effect in contemporary practice. METHODS: The National Readmission Database was queried to identify patients undergoing CABG between January 1, 2015 and December 31, 2016. Risk-adjusted in-hospital morbidity, mortality, length-of-stay, cost, and 30-day readmission were compared between low-, intermediate-, and high-volume centers. RESULTS: A total of 411 159 CABG hospitalizations at 1558 hospitals were included. Hospitals were classified into three tertiles (high > 250, intermediate 100-250, and low-volume < 100). Hospitals in the highest tertile (n = 568) performed 73.9% of all CABG operations, while those in the intermediate (n = 452), and low (n = 538) volume tertiles performed only 21.7% and 4.4% of all CABGs, respectively. The median number of CABGs performed at high-, intermediate-, and low-volume hospitals was 45 316 335, respectively. After risk adjustment, undergoing CABG at low- or intermediate- volume hospital (vs high-volume hospitals) was associated with higher in-hospital death (odd ratio [OR] = 1.31, 95% confidence interval [CI], 1.19-1.44, and OR = 1.11, 95% CI, 1.05-1.17, respectively, P < .001). Similarly, adjusted odds of stroke, acute kidney injury, and blood transfusion were higher at low- and intermediate-volume centers compared with high-volume centers. Undergoing CABG at a low-volume center was associated with 50% higher adjusted cost and 77% higher adjusted 30-day readmissions. CONCLUSIONS: In contemporary practice, in which one-third of CABG-capable hospitals perform < 100 CABG operations annually, a strong relationship is observed between surgical volume and adjusted in-hospital morbidity, mortality, cost, and 30-day readmission.

Contemporary trends and outcomes of mitral valve surgery for infective endocarditis.

BACKGROUND: Contemporary data on mitral valve (MV) surgery in patients with infective endocarditis (IE) are limited. METHODS: The National Inpatient Sample was queried to identify patients with IE who underwent MV surgery between 2003 and 2016. We assessed (a) temporal trends in the incidence of MV surgery for IE, (b) morbidity, mortality, and cost of MV repair vs replacement, and (c) predictors of in-hospital mortality. RESULTS: The proportion of MV operations involving patients with IE increased from 5.4% in 2003 to 7.3%, and the proportion of MV repair among those undergoing surgery for IE increased from 15.2% to 25.0% (Ptrend < .001). In-hospital mortality was higher in the replacement group (11.3% vs 8.1%; P < .001), and this excess mortality persisted after propensity score matching (11.2% vs 8.1%; P < .001), and in sensitivity analyses excluding concomitant surgery (unadjusted 11.3% vs 4.8%; adjusted 8.5% vs 4.5%; P < .001), and stratifying patients by the time of operation (within 7 days, 11.3% vs 6.8%; P < .001 and >7 days, 11.9% vs 9.1%; P = .012). In the propensity-matched cohorts, shock and need for tracheostomy were more frequent in the replacement group, but rates of stroke, pacemaker implantation, new dialysis, and blood transfusion were similar. Mitral valve repair was, however, associated with shorter hospitalizations, more home discharges, and less cost. In a multivariate regression analysis, age above 70 and chronic dialysis were the strongest predictors of in-hospital mortality. CONCLUSION: Mitral valve repair in IE patients is associated with lower in-hospital mortality, resource utilization, and cost compared with MV replacement.

Surgical Techniques for Mitral Valve Repair: A Pathoanatomic Grading System.

Mitral valve surgery has evolved over 4 decades from one based on the principles of prosthetic replacement to a subspecialty with a foundation based on the principles of repair. This review will attempt to enumerate the contemporary techniques of mitral valve repair and a pathoanatomically directed approach with which to apply them by focusing on degenerative disease and associated complexities.