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Background: Sodium-glucose cotransporter 2 inhibitors have been demonstrated to promote reverse cardiac remodeling in people with diabetes or heart failure. Although it has been theorized that sodium-glucose cotransporter 2 inhibitors might afford similar benefits in people without diabetes or prevalent heart failure, this has not been evaluated. We sought to determine whether sodium-glucose cotransporter 2 inhibition with empagliflozin leads to a decrease in left ventricular (LV) mass in people without type 2 diabetes or significant heart failure. Methods: Between April 2021 and January 2022, 169 individuals, 40 to 80 years of age, without diabetes but with risk factors for adverse cardiac remodeling were randomly assigned to empagliflozin (10 mg/d; n=85) or placebo (n=84) for 6 months. The primary outcome was the 6-month change in LV mass indexed (LVMi) to baseline body surface area as measured by cardiac magnetic resonance imaging. Other measures included 6-month changes in LV end-diastolic and LV end-systolic volumes indexed to baseline body surface area and LV ejection fraction. Results: Among the 169 participants (141 men [83%]; mean age, 59.3±10.5 years), baseline LVMi was 63.2±17.9 g/m 2 and 63.8±14.0 g/m 2 for the empagliflozin- and placebo-assigned groups, respectively. The difference (95% CI) in LVMi at 6 months in the empagliflozin group versus placebo group adjusted for baseline LVMi was –0.30 g/m 2 (–2.1 to 1.5 g/m 2 ; P =0.74). Median baseline (interquartile range) NT-proBNP (N-terminal-pro B-type natriuretic peptide) was 51 pg/mL (20–105 pg/mL) and 55 pg/mL (21–132 pg/mL) for the empagliflozin- and placebo-assigned groups, respectively. The 6-month treatment effect of empagliflozin versus placebo (95% CI) on blood pressure and NT-proBNP (adjusted for baseline values) were –1.3 mm Hg (–5.2 to 2.6 mm Hg; P =0.52), 0.69 mm Hg (–1.9 to 3.3 mm Hg; P =0.60), and –6.1 pg/mL (–37.0 to 24.8 pg/mL; P =0.70) for systolic blood pressure, diastolic blood pressure, and NT-proBNP, respectively. No clinically meaningful between-group differences in LV volumes (diastolic and systolic indexed to baseline body surface area) or ejection fraction were observed. No difference in adverse events was noted between the groups. Conclusions: Among people with neither diabetes nor significant heart failure but with risk factors for adverse cardiac remodeling, sodium-glucose cotransporter 2 inhibition with empagliflozin did not result in a meaningful reduction in LVMi after 6 months. Registration: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT04461041.

Objectives We sought to evaluate the early outcomes of patients undergoing a Bentall procedure after previous cardiac surgery. Methods From 1990 to 2014, 473 patients underwent a Bentall procedure after previous cardiac surgery with a composite valve graft at a single institution: composite valve graft with a mechanical prosthesis (n = 256) or composite valve graft with a bioprosthesis (n = 217). Patients were excluded if their index operation was less than 30 days before the reoperation. The primary outcome was 30-day mortality. The secondary outcome was a composite of major morbidity and operative mortality: stroke, renal failure, prolonged mechanical ventilation, deep sternal infection, or reoperation during the same admission. Multivariable logistic regression was used to identify risk factors associated with the primary and secondary outcomes of interest. Results Median age was 57 (interquartile range, 44-67) years, and 349 patients (74%) were male. Median time between index surgery and reoperation was 13 (interquartile range, 8-21) years. A total of 178 patients (38%) underwent urgent or emergency intervention, 61 patients (13%) had active endocarditis/abscess, 87 patients (19%) had left ventricular ejection fraction less than 40%, and 262 patients (55%) had undergone more than 1 previous operation. Previous operations (not mutually exclusive) included coronary artery bypass grafting (n = 58, 12%), aortic valve/root replacement (n = 376, 80%) or repair (n = 36, 8%), and other surgical interventions (n = 245, 52%). Ninety-six patients (20%) had undergone coronary reimplantation during the previous operation, which consisted of a Bentall procedure in 81 patients, a Ross operation in 8 patients, a valve-sparing root replacement in 4 patients, and an arterial switch in 3 patients. At the time of the reoperative Bentall, both coronary arteries were reimplanted directly in 357 patients (77%), whereas 79 patients (17%) received at least 1 interposition graft. In 26 patients (5%), at least 1 of the native coronary arteries was oversewn and a vein graft bypass was performed. Thirty-day mortality occurred in 37 patients (7.8%), and 152 patients (32%) had major morbidity and operative mortality. On multivariable analysis, risk factors associated with increased 30-day mortality included older age and coronary reimplantation by a technique other than direct anastomosis. Indirect coronary reimplantation was also associated with a higher incidence of major morbidity and operative mortality, as were more than 1 previous cardiac operation and preoperative New York Heart Association functional class III/IV or greater. Conclusions In the largest reported cohort of aortic root replacement after previous cardiac surgery, the reoperative Bentall procedure was associated with a significant operative risk. The need for complex coronary reimplantation techniques was an important factor associated with adverse perioperative events.

Background Minimally invasive extracorporeal circulation (MiECC) is employed as a strategy to attenuate the physiologic disturbance caused by cardiopulmonary bypass. The aim of this study was to compare the coagulation profile of MiECC to an optimized conventional extracorporeal circuit (OpECC) with regards to platelet function, rotational thromboelastometry and blood product usage. Methods A retrospective analysis of coronary artery bypass grafting operations using either MiECC or OpECC was performed at a single institution. Results A total of 112 patients were included, with 61 receiving MiECC and 51 OpECC patients. OpECC patients had a significantly larger BSA (1.95+/- 0.22m2 vs 1.88 +/- 0.18m2, p = 0.034), than those who received MiECC. No difference between groups was observed regarding red blood cell, plasma, and platelet transfusions. Functional platelet count during the warming phase of cardiopulmonary bypass was found to be higher in the MiECC group ((136 (102–171) x109/L vs 109 (94–136) x109/L), p = 0.027), as were functional platelets as a percent of total platelet count ((86 (77–91)% vs 76 (63–82)%), p = 0.003). There were no significant differences between other outcomes such as operative mortality, incidence of stroke, and intensive care unit length of stay. Conclusion While we did not see a difference in blood transfusions, MiECC resulted in a statistically significant advantage over OpECC with regards to preservation of functional platelets.

Background Despite known clinical risk factors, predicting anthracycline cardiotoxicity remains challenging. Objectives This study sought to develop a clinical and genetic risk prediction model for anthracycline cardiotoxicity in childhood cancer survivors. Methods We performed exome sequencing in 289 childhood cancer survivors at least 3 years from anthracycline exposure. In a nested case-control design, 183 case patients with reduced left ventricular ejection fraction despite low-dose doxorubicin (≤250 mg/m2), and 106 control patients with preserved left ventricular ejection fraction despite doxorubicin >250 mg/m2 were selected as extreme phenotypes. Rare/low-frequency variants were collapsed to identify genes differentially enriched for variants between case patients and control patients. The expression levels of 5 top-ranked genes were evaluated in human induced pluripotent stem cell–derived cardiomyocytes, and variant enrichment was confirmed in a replication cohort. Using random forest, a risk prediction model that included genetic and clinical predictors was developed. Results Thirty-one genes were differentially enriched for variants between case patients and control patients (p < 0.001). Only 42.6% case patients harbored a variant in these genes compared to 89.6% control patients (odds ratio: 0.09; 95% confidence interval: 0.04 to 0.17; p = 3.98 × 10–15). A risk prediction model for cardiotoxicity that included clinical and genetic factors had a higher prediction accuracy and lower misclassification rate compared to the clinical-only model. In vitro inhibition of gene-associated pathways (PI3KR2, ZNF827) provided protection from cardiotoxicity in cardiomyocytes. Conclusions Our study identified variants in cardiac injury pathway genes that protect against cardiotoxicity and informed the development of a prediction model for delayed anthracycline cardiotoxicity, and it also provided new targets in autophagy genes for the development of cardio-protective drugs. (Preventing Cardiac Sequelae in Pediatric Cancer Survivors [PCS2]; NCT01805778), Central Illustration

Supplemental Digital Content is available in the text., Background: Hypertrophic cardiomyopathy is the leading cause of sudden cardiac death (SCD) in children and young adults. Our objective was to develop and validate a SCD risk prediction model in pediatric hypertrophic cardiomyopathy to guide SCD prevention strategies. Methods: In an international multicenter observational cohort study, phenotype-positive patients with isolated hypertrophic cardiomyopathy 70% prediction accuracy and incorporates risk factors that are unique to pediatric hypertrophic cardiomyopathy. An individualized risk prediction model has the potential to improve the application of clinical practice guidelines and shared decision making for implantable cardioverter defibrillator insertion. Registration: URL: https://www.clinicaltrials.gov; Unique identifier: NCT0403679.

Valve-sparing root replacement (VSRR) has excellent outcomes when performed in experienced centers in well-selected patients. It is suggested that reimplantation of the aortic valve may have better durability than remodeling in patients with Marfan syndrome (MFS), although long-term comparative data are limited.Between 1988 and 2018, 194 patients with MFS underwent VSRR at our institution. From these, we derived a propensity-matched cohort of 68 patients (44 who underwent reimplantation and 24 who had remodeling). Early outcomes included death and perioperative complications. Late outcomes were survival, probability of aortic insufficiency, and reintervention up to 20 years of follow-up. Median follow-up was 17.8 years (interquartile range, 12.0-20.6 years) for the entire matched cohort.Baseline variables were similar between reimplantation and remodeling patients after matching: age (39 ± 12 vs 40 ± 13 years, P = .75) and male sex (28 [64%] vs 15 [63%], P = 1.0). Similar 20-year survival was observed after reimplantation compared with remodeling (82% vs 72%, P = .20), whereas the probability of developing greater than mild aortic insufficiency at 20 years was increased after remodeling (5.8% vs 13%, P = .013). More patients underwent reoperation on the aortic valve after a remodeling procedure than after reimplantation of the aortic valve (18% vs 0%, P = .018).VSRR provides excellent long-term survival and freedom from valve-related complications outcomes in patients with MFS. Reimplantation of the aortic valve was associated with a lower risk of aortic valve reoperation and aortic insufficiency than the remodeling procedure after 2 decades of follow-up.

Aortic cusp fenestrations are common in patients with aortic root aneurysm, and their management during aortic valve repair remains controversial. We believe that fenestrations in the area of the commissures may rupture after reimplantation of the aortic valve because this operation increases the mechanical stress on the cusps. For this reason we have reinforced the free margin of the aortic cusp with fenestration with fine Gore-Tex sutures (WL Gore). This study examines the outcomes of reimplantation of the aortic valve in patients who had cusp fenestration reinforced with Gore-Tex sutures.A review of all patients who had reimplantation of the aortic valve for aortic root aneurysm disclosed 111 patients who had at least 1 cusp fenestration reinforced with a double layer of a fine Gore-Tex suture. The outcomes of these patients were examined and compared with a group of patients without fenestration using propensity score analysis. All patients were followed prospectively with images of the heart.The median follow-up was 8.3 years. Overall the cumulative incidence of aortic valve reintervention at 15 years was 4.8% and the cumulative incidence of aortic insufficiency of moderate or severe degree was 9.2%. Comparison of outcomes of patients with and without fenestrations showed similar results up to 15 years of follow-up.Reinforcement of the free margins of cusps with fenestrations using Gore-Tex sutures is safe and does not seem to adversely affect the durability of reimplantation of the aortic valve.

Aims Current guidelines recommend initiating family screening for hypertrophic cardiomyopathy (HCM) after age 10 or 12 years unless early screening criteria are met. The aim was to evaluate if current screening guidelines miss early onset disease. Methods and results Children who underwent family screening for HCM before age 18 years were analysed. Major cardiac events (MaCEs) were defined as death, sudden cardiac death (SCD), or need for major cardiac interventions (myectomy, implantable cardioverter-defibrillator insertion, transplantation). Of 524 children screened, 331 were under 10 years of age, 9.9% had echocardiographic evidence of HCM, and 1.1% were symptomatic at first screening. The median (interquartile range) age at HCM onset was 8.9 (4.7–13.4) years, and at MaCE was 10.9 (8.5–14.3) years with a median time to MaCE from HCM onset of 1.5 (0.5–4.1) years. About 52.5% phenotype-positive children and 41% with MaCEs were Conclusion A third of children not eligible for early screening by current guidelines had phenotype-positive HCM. MYH7 and MYBC3 mutation-positive patients were at highest risk for developing early HCM and experiencing an event or requiring a major intervention. Our findings suggest that younger family members should be considered for early clinical and genetic screening to identify the subset in need of closer monitoring and interventions.

Objectives The objectives of this study were to examine operative and long-term results of combined aortic and mitral valve replacement when reconstruction of the fibrous skeleton of the heart is needed because of calcification, abscess, previous operations, or patient-prosthesis mismatch. Methods From 1985 to 2020, 182 consecutive patients underwent combined aortic and mitral valve replacement with reconstruction of the intervalvular fibrous skeleton in all cases and also the posterior mitral annulus in 63 patients. Bovine pericardium or Dacron grafts were used for the reconstructions. Median follow-up was 7.5 (interquartile range, 2.1-12.6) years and 98% complete. Results Patient mean age was 62 years; 69% had 1 or more previous valve operations, and 92% were functional class III or IV. The indications for reconstruction were extensive calcification of the fibrous skeleton in 34%, abscess in 13%, tissue damage secondary to previous operations in 39%, and patient-prosthesis mismatch of the mitral valve in 13%. Bovine pericardium was used in two-thirds of cases and Dacron grafts in one-third. Operative mortality was 13.2% and postoperative complications were common. Survival at 1, 10, and 20 years was 81.8%, 51.1%, and 23.7%, respectively. Fourteen patients required reoperation and 3 transcatheter interventions. The cumulative probability of reinterventions at 1, 10, and 20 years were 3.3%, 5.8%, and 9.1%, respectively. Most patients experienced symptomatic improvement postoperatively. Conclusions Reconstructions of the fibrous skeleton of the heart are associated with high operative mortality but the long-term results are satisfactory because most patients would not have survived without surgical intervention.

Background: Despite known clinical and genetic risk factors, predicting anthracycline cardiotoxicity remains challenging. Objective: To develop a risk prediction model for anthracycline cardiotoxicity in childhood cancer survivors. Methods: We performed exome sequencing in 289 childhood cancer survivors at least 3 years from anthracycline exposure. In a nested case-control design, 183 cases with LV ejection fraction (LVEF) ≤55% despite low-dose doxorubicin (DOX) (≤250 mg/m2), and 106 controls with LVEF >55% despite DOX >250 mg/m2 were selected as extreme phenotypes. Rare/low-frequency variants were collapsed to identify genes differentially enriched for variants between cases and controls. The top-ranked genes were functionally evaluated in human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and variant enrichment was confirmed in a replication cohort. Using random forest, a risk prediction model that included genetic and clinical predictors was developed. Results: Thirty-one genes were differentially enriched for variants between cases and controls (p-15 ] suggesting that absence of these variants may predispose to cardiotoxicity. A risk prediction model for cardiotoxicity that included clinical and genetic factors had a higher prediction accuracy and lower misclassification rate compared to the clinical model. In vitro inhibition of gene-associated pathways ( PI3KR2, ZNF827 ) provided protection from cardiotoxicity in CMs. Conclusions: Our study identified variants that protect against cardiotoxicity and informed the development of a prediction model for delayed anthracycline cardiotoxicity, and also provided new targets in autophagy genes for development of cardio-protective drugs.

Objective To examine the late outcomes of reimplantation of the aortic valve (RAV) in patients followed prospectively since surgery. Methods All 465 patients who had RAV from 1989 to 2018 were followed prospectively with periodic clinical and echocardiographic assessments. Mean follow-up was 10 ± 6 years and 98% complete. Results Patients' mean age was 47 ± 5.1 years, and 78% were men. The aortic root aneurysm was associated with Marfan syndrome in 164 patients, Loeys–Dietz syndrome in 13, bicuspid aortic valve (BAV) in 67, and type A aortic dissection in 33. Aortic insufficiency (AI) was greater than mild in 298 patients. Concomitant procedures were performed in 105 patients. There were 5 operative and 51 late deaths. At 20 years, 69.1% of patients were alive and free from aortic valve reoperation, and the cumulative probability of aortic valve reoperation with death as a competing risk was 6.0%, and the cumulative probability of developing moderate or severe AI was 10.2%. Only time per 1-year interval was associated with the development of postoperative AI by multivariable analysis (hazard ratio, 1.06; 95% confidence interval, >1.02-1.10; P = .006). Gradients across preserved BAV increased in 5 patients, and 1 required reoperation for aortic stenosis. Distal aortic dissections occurred in 22 patients, primarily in those with associated genetic syndromes. Conclusions RAV provides excellent long-term results, but there is a progressive rate of AI over time, and patients with BAV may develop aortic stenosis. Patients with genetic syndromes have a risk of distal aortic dissections. Continued surveillance after RAV is necessary.

Supplemental Digital Content is available in the text., Background: Aortic valve stenosis is the most common type of congenital left ventricular (LV) outflow tract obstruction. Balloon aortic valvuloplasty (BAV) has become the first-line treatment pathway in many centers. Our aim was to assess the trajectory of LV remodeling following BAV in children and its relationship to residual aortic stenosis (AS) and insufficiency (AI). Methods: Children

Background In patients with severe aortic regurgitation (AR), the left ventricular ejection fraction (LVEF) and left ventricle (LV) size are crucial for determining clinical prognosis and timing of valve intervention. In clinical practice, LV internal diameters obtained at end-diastole are used to assess the degree of LV dilatation. Whether quantification of LV volumes would provide more robust information as compared to LV linear dimensions is unknown. Methods We retrospectively analyzed preoperative and postoperative transthoracic echocardiograms of patients who underwent aortic valve replacement (AVR) for severe AR. Indexed linear LV end-diastolic and end-systolic diameters along with indexed LV end-diastolic and end-systolic volumes were obtained as per current guidelines. Post-AVR LV reverse remodeling, defined as ≥10% reduction in measures of LV volumes (Teichholz and Simpson's methods), was determined. Positive and negative agreement was calculated between the volume- and diameter-based LV reverse remodeling. Results Sixty-two consecutive patients were included. Nine patients (17%) without LV reverse remodeling based on Teichholz were reclassified as having LV reverse remodeling based on Simpson (positive agreement 0.846 [95% CI 0.772, 0.921], negative agreement 0.200 [95% CI -0.350, 0.435]). Left ventricle (LV) reverse remodeling assessed by the Teichholz method was underestimated by a mean of 31 mL/m2 (β = -0.65 [95% CI -1.06 to -0.24], P = .003) compared to Simpson method. Conclusion Compared to the volume-based method, diameter-based LV measurement incorrectly identified LV reverse remodeling post-AVR in 17% of patients with severe AR. Left ventricle (LV) volume may be a better measure to assess LV remodeling post-AVR than LV diameter-based measurements.

Background The number of transplantations performed for adult congenital heart disease (ACHD) patients is increasing. We sought to compare survival and post-transplantation complications, including graft failure, rejection, dialysis, and use of a right ventricular assist device, between ACHD and a cohort of dilated (DCM) and ischemic (ICM) cardiomyopathy patients matched by age and year of transplantation. Methods We retrospectively reviewed our single-institution heart transplantation database and selected all patients who had surgery from 1988 to 2017. In our primary analysis, we looked at survival and post-transplantation complications across cardiomyopathy groups. Our secondary analysis was matched to mitigate era effects as well as differences in age at transplant. Results We analyzed a cohort consisting of 303 heart transplant patients with cardiomyopathy due to either 1) ACHD (n = 38), 2) ICM (n = 110), or 3) DCM (n = 155). Kaplan-Meier analysis and a multivariable Cox proportional hazard regression model were used for all-cause mortality, and cause-specific hazard regression for cause-specific mortality and morbidity. There was no statistically significant survival difference across groups. The 1-year survival was 68.5% for ACHD, 85.4% for ICM, and 85.5% for DCM. In multivariable analysis, ICM and DCM patients showed a 66% lower risk of death relative to the ACHD group. The matched analysis showed no significant difference in survival across groups. Conclusions ACHD patients represent a growing high-risk patient cohort referred for transplantation. To improve survival outcomes we need to address modifiable risk factors.

This study examines the durability of mitral valve (MV) repair for mitral regurgitation using chordal replacement with expanded polytetrafluoroethylene sutures to correct leaflet prolapse.Isolated chordal replacement was used to correct prolapse in 186 (24.9%) patients and combined with leaflet resection in 560 (75.1%). Patients were followed prospectively with periodical clinical and echocardiographic assessments for a median follow-up of 11 years (range, 7-16 years).Patients' median age was 58 years (range, 48-67 years) and 516 (69.2%) were men. Bileaflet prolapse was present in 63% of patients and advanced myxomatous degeneration was present in 32%. The number of neochords per repaired valve increased over time and was not associated with MV reoperation or recurrent mitral regurgitation. The cumulative incidence of MV reoperation with death as a competing risk was 4.2% (95% confidence interval [CI], 2.4-6.0) at 20 years. Multivariable analysis revealed that previous cardiac operations (hazard ratio, 5.70; 95% CI, 1.96-16.53; P = .001), and isolated anterior leaflet prolapse (hazard ratio, 3.92; 95% CI, 1.106-13.91; P = .034) were associated with increased hazard of MV reoperation. The probability of recurrent moderate or severe mitral regurgitation using repeated measures regression models was 14.1% (95% CI, 10.3-19.0) at 20 years. Variables associated with recurrent MR in multivariable regression analysis were left ventricular ejection40% (hazard ratio, 3.57; 95% CI, 1.37-9.32; P = .009) and preoperative complete heart block (hazard ratio, 5.90; 95% CI, 2.47-14.09; P .001).Chordal replacement with expanded polytetrafluoroethylene sutures provides stable MV function in most patients during the first 2 decades of follow-up.

Background Mitral valve (MV) repair has become the standard therapy for mitral regurgitation (MR) due to degenerative diseases, but information on late outcomes is limited. Objectives The purpose of this study was to examine the late results of MV repair for MR in a large cohort of patients. Methods A total of 1,234 consecutive patients (median age 59 years; 70.4% men) had MV repair for MR due to leaflet prolapse and were followed prospectively for a median of 13 years (interquartile range: 8 to 34 years) with periodical echocardiographic studies. There were 163 patients still at risk at 20 years. Cumulative incidences of adverse events and associated factors were examined with death as a competing outcome. Results At 20 years, reoperation-free survival was 60.4% (95% confidence interval: 56.2% to 64.2%) and the cumulative incidence of cardiac and valve-related deaths was 12%, noncardiac deaths 21.3%, reoperation on the MV 4.6%, infective endocarditis 1.1%, thromboembolism 10.3%, and bleeding 6.4%. The probability of recurrent moderate or severe MR was 12.5%, persistent or new moderate or severe tricuspid regurgitation (TR) 20.8%, and new atrial fibrillation (AF) 32.4%. Multivariable analysis identified older age, complete heart block, MV repair without annuloplasty ring, and the degree of myxomatous degeneration of the MV to be associated with recurrent MR. The development of AF and TR was unrelated to recurrent MR. Conclusions MV reoperation was uncommon after MV repair, but there was an increasing incidence of recurrent MR, TR, and new AF over time.

The interactive relationship between left ventricular (LV) ejection fraction (LVEF) and LV size in predicting perioperative outcomes after cardiac surgery has not been clarified.This study reviewed all patients who underwent cardiac surgery between 2010 and 2016 with either preserved LVEF (60%; n = 5685) or severely reduced LVEF (20%; n = 143). LV size was categorized by using either LV end-diastolic or end-systolic diameter or a qualitative assessment, as follows: normal, smaller than 4 cm; mildly enlarged, 4.1 to 5.4 cm moderately enlarged, 5.5 to 6.5 cm; and severely enlarged, larger than 6.5 cm. Using propensity-score analysis, we matched patients with LVEF less than 20% (n = 143) in a 3:1 ratio with patients with LVEF greater than 60% (n = 429).There were significant differences in mortality, major morbidity, and operative mortality and prolonged length of stay between patients with LVEF less than 20% and LVEF greater than 60%. In patients with LVEF less than 20%, there were no significant differences in outcomes between those with an LV size of 5.4 cm or smaller and an LV size of 5.5 cm or larger. In patients undergoing isolated coronary artery bypass grafting (CABG), LV size predicted mortality, major morbidity, and operative mortality (odds ratio, 5.5 [95% confidence interval, 2.0 to 15.7]; P.001) and prolonged length of stay (odds ratio, 3.4 [95% confidence interval, 1.2 to 10.3]; P = .026), respectively.LVEF is more important than LV size in predicting outcomes after cardiac surgery. However, in patients undergoing isolated CABG, LV size has an interactive effect with LVEF and can potentially aid the decision-making process. Risk adjustment models using only LVEF may be inaccurate, particularly with respect to isolated CABG procedures.

Objective The study objective was to examine the long-term results of the Ross procedure in a cohort of patients followed prospectively for more than 2 decades. Methods From 1990 to 2004, 212 consecutive patients with a median age (interquartile range) of 34 years (28-41) underwent the Ross procedure; 82% had congenital aortic valve disease. The technique of aortic root replacement was used in one half of the patients. Patients have been followed prospectively for a median (interquartile range) of 18.0 (14.6-21.2) years. Valve function was assessed by echocardiography. Results Cumulative mortality at 20 years was 10.8% (95% confidence interval, 6.5-17.8). Thirty patients required Ross-related reoperations and 3 for coronary artery disease. The cumulative probability of Ross-related reoperations at 20 years was 16.8% (95% confidence interval, 11.3-24.5), on the pulmonary autograft was 11.5% (95% confidence interval, 7.2-18.0), and on the pulmonary homograft was 8.2% (4.6-14.7). The implantation technique was not associated with the cumulative incidence of reoperations on the pulmonary autograft. The development of moderate or severe aortic insufficiency and pulmonary homograft dysfunction increased with time. At 20 years, the probability of aortic insufficiency was 13% (95% confidence interval, 8.0-20.3) and of pulmonary homograft dysfunction was 19.7% (95% confidence interval, 13.9-27.2). Preoperative aortic insufficiency was associated with increased odds of postoperative aortic insufficiency. Conclusions The long-term results of the Ross procedure are excellent regardless of the implantation technique, but there is a progressive deterioration of function of both semilunar valves.

Children with hypertrophic cardiomyopathy (HCM) experience sudden cardiac death (SCD) and other life-threatening events. We assessed if affected gene and variant burden predict outcomes. Patients18 years old with primary HCM with a pathogenic variant or variant of uncertain significance in cardiomyopathy genes were included. Association of gene and variant number and type with freedom from major adverse cardiac events (MACE), that is, ICD insertion, myectomy, aborted SCD, transplantation or death, was assessed by Cox regression. A total of 98 of 155 gene-tested patients carried a non-benign variant. The primary affected gene was MYH7 in 35% (MYH7+) and MYBPC3 in 49% (MYBPC3+). MYH7+ patients had earlier disease onset and higher risk of MACE (hazard ratio 2.7, 95% CI 1.3-5.7). Risk of MACE was also higher in patients with multiple variants (n = 16) (HR 2.5, CI: 1.1-5.9) compared to a propensity score-matched single variant subset, after adjustment for primary gene, and in patients with de novo (n = 18) vs inherited variants (HR 5.7, CI: 2.6-12.7). Affected gene (eg, MYH7), higher variant burden and de novo variant status are independently associated with earlier onset and higher frequency of adverse outcomes in pediatric HCM, highlighting the importance of genetic risk stratification in HCM.

Dopamine depletion in Parkinson's disease (PD) alters the neuronal activity in basal ganglia circuits. Characterizing these changes in network activity is an important step in understanding the disease and how therapies mitigate symptoms. Non-linear analysis methods can complement the traditional description of neuronal firing characteristics. Here we examine the entropy of subthalamic neurons in PD patients undergoing stereotactic surgery for deep brain stimulation (DBS). The activity of 8 neurons was recorded prior to, during, and following systemic administration of the dopamine agonist apomorphine at clinically effective doses. Apomorphine induced a decrease in entropy measured in the inter-spike intervals of sub-thalamic neurons in 6 of the 8 neurons. This is the first report that anti-parkinsonian drugs affect non-linear features of neuronal firing in the basal ganglia of parkinsonian patients.

Background Tacrolimus pharmacokinetics are influenced by age and CYP3A5 genotype with CYP3A5 expressors (CYP3A5*1/*1 or *1/*3) being fast metabolizers. However, the benefit of genotype-guided dosing in pediatric solid organ transplantation has been understudied. Objective To determine whether age and CYP3A5 genotype-guided starting dose of tacrolimus result in earlier attainment of therapeutic drug concentrations. Setting Single hospital-based transplant center. Methods This was a randomized, semi-blinded, 30-day pilot trial. Between 2012 and 2016, pediatric patients listed for solid organ transplant were consented and enrolled into the study. Participants were categorized as expressors, CYP3A5*1/*1 or CYP3A5*1/*3, and nonexpressors, CYP3A5*3/*3. Patients were stratified by age (≤ or > 6 years) and randomized (2:1) after transplant to receive genotype-guided (n = 35) or standard (n = 18) starting dose of tacrolimus for 36-48 hours and were followed for 30 days. Results Median age at transplant in the randomized cohort was 2.1 (0.75-8.0) years; 24 (45%) were male. Participants in the genotype-guided arm achieved therapeutic concentrations earlier at a median (IQR) of 3.4 (2.5-6.6) days compared to those in the standard dosing arm of 4.7 (3.5-8.6) days (P = 0.049), and had fewer out-of-range concentrations [OR (95% CI) = 0.60 (0.44, 0.83), P = 0.002] compared to standard dosing, with no difference in frequency of adverse events between the two groups. Conclusions CYP3A5 genotype-guided dosing stratified by age resulted in earlier attainment of therapeutic tacrolimus concentrations and fewer out-of-range concentrations.

Object The aim of the current study was to examine and compare the aftereffects of local high-frequency microstimulation through the recording electrode on the firing of neurons in the subthalamic nucleus (STN) and the substantia nigra pars reticulata (SNr) in patients undergoing surgery for deep brain stimulation. Deep brain stimulation has been playing an increasing role in the treatment of Parkinson disease, with the subthalamic nucleus (STN) being the preferred implantation target. Changes in cellular activity indicative of the borders of the STN are typically used during surgery to determine the extent of the STN and locate the optimal target, but in some cases borders may be difficult to identify. In this study the authors compared the effects of microstimulation in the SNr and STN. In previous studies they have shown that microstimulation in the internal globus pallidus, which is functionally similar to the SNr, inhibits firing, whereas similar microstimulation in the STN has minimal effect. The presence of inhibition in the SNr but not in the STN could be used as an additional criterion to help identify the location of the border between the STN and SNr. Methods Dual microelectrode recordings were performed during stereotactic surgery in 4 patients. Well-isolated high-amplitude units were stimulated extracellularly through the recording microelectrode with 0.5-second trains of high frequency (200 Hz) and low current (≤ 5 μA). Results In the majority (92%) of SNr neurons, this type of stimulation led to a period of inhibition lasting several hundreds of milliseconds following the end of the train. In contrast, only 1 neuron of 70 judged to be in the STN by other criteria was inhibited by this type of microstimulation, and this neuron was located at the ventral border of the STN. Conclusions These findings indicate that prolonged inhibition of firing following low-amplitude high-frequency microstimulation via the recording electrode is a consistent feature of almost all SNr neurons and rarely if ever occurs in STN neurons. This feature therefore provides a useful additional finding that can be used to help identify the border between the STN and SNr.

The mammalian spinal cord contains a locomotor central pattern generator (CPG) that can produce alternating rhythmic activity of flexor and extensor motoneurones in the absence of rhythmic input and proprioceptive feedback. During such fictive locomotor activity in decerebrate cats, spontaneous omissions of activity occur simultaneously in multiple agonist motoneurone pools for a number of cycles. During these ‘deletions’, antagonist motoneurone pools usually become tonically active but may also continue to be rhythmic. The rhythmic activity that re-emerges following a deletion is often not phase shifted. This suggests that some neuronal mechanism can maintain the locomotor period when motoneurone activity fails. To account for these observations, a simplified computational model of the spinal circuitry has been developed in which the locomotor CPG consists of two levels: a half-centre rhythm generator (RG) and a pattern formation (PF) network, with reciprocal inhibitory interactions between antagonist neural populations at each level. The model represents a network of interacting neural populations with single interneurones and motoneurones described in the Hodgkin-Huxley style. The model reproduces the range of locomotor periods and phase durations observed during real locomotion in adult cats and permits independent control of the level of motoneurone activity and of step cycle timing. By altering the excitability of neural populations within the PF network, the model can reproduce deletions in which motoneurone activity fails but the phase of locomotor oscillations is maintained. The model also suggests criteria for the functional identification of spinal interneurones involved in the mammalian locomotor pattern generation.

We examined the features of spontaneous deletions of bursts of motoneuron activity that can occur within otherwise rhythmic alternating flexor and extensor activity during fictive locomotion and scratch in adult decerebrate cats. Deletions of activity were observed both in hindlimb flexor and extensor motoneuron pools during brain stem–stimulation-evoked fictive locomotion but only in extensors during fictive scratch. Paired intracellular motoneuron recordings showed that deletions reduced the depolarization of homonymous motoneurons in qualitatively similar ways. Differences occurred in the extent to which activity in synergist motoneuron pools operating at other joints within the limb was reduced during deletions. The timing of the rhythmic activity that followed a deletion was often at an integer multiple of the preexisting locomotor or scratch cycle period. This maintenance of cycle period was also seen during deletions in which there was a complete failure of motoneuron depolarization. The activity of antagonist motoneurons was usually sustained during deletions with some rhythmic modulation at intervals of the preexisting cycle period. We discuss an organization of the central pattern generator for locomotion and scratch that functions as a single rhythm generator with separate and multiple pattern formation modules for controlling the hyper- and depolarization of subsets of motoneurons within the limb.

A mass spectrometric analysis of proteins partitioning into Triton X-114 from purified hepatic Golgi apparatus (84% purity by morphometry, 122-fold enrichment over the homogenate for the Golgi marker galactosyl transferase) led to the unambiguous identification of 81 proteins including a novel Golgi-associated protein of 34 kDa (GPP34). The membrane protein complement was resolved by SDS-polyacrylamide gel electrophoresis and subjected to a hierarchical approach using delayed extraction matrix-assisted laser desorption ionization mass spectrometry characterization by peptide mass fingerprinting, tandem mass spectrometry to generate sequence tags, and Edman sequencing of proteins. Major membrane proteins corresponded to known Golgi residents, a Golgi lectin, anterograde cargo, and an abundance of trafficking proteins including KDEL receptors, p24 family members, SNAREs, Rabs, a single ARF-guanine nucleotide exchange factor, and two SCAMPs. Analytical fractionation and gold immunolabeling of proteins in the purified Golgi fraction were used to assess the intra-Golgi and total cellular distribution of GPP34, two SNAREs, SCAMPs, and the trafficking proteins GBF1, BAP31, and alpha(2)P24 identified by the proteomics approach as well as the endoplasmic reticulum contaminant calnexin. Although GPP34 has never previously been identified as a protein, the localization of GPP34 to the Golgi complex, the conservation of GPP34 from yeast to humans, and the cytosolically exposed location of GPP34 predict a role for a novel coat protein in Golgi trafficking.

Deep brain stimulation of the basal ganglia and other brain regions has been used successfully to treat a variety of neurological disorders. However, the mechanisms by which it works, remain unclear. In a previous study, we showed that locally delivered single current pulses delivered from a nearby microelectrode are sufficient to inhibit firing in the internal globus pallidus for tens of milliseconds. The GPi and the substantia nigra pars reticulata are the output nuclei of the basal ganglia and share many anatomical and physiological features. The goal of the current study was to examine the after-effects of trains of high-frequency microstimulation on neuronal firing in the GPi of Parkinson's disease and dystonia patients as well as in the SNr of PD patients. Microelectrode recordings and microstimulation were performed in a total of 57 patients during stereotactic surgery. We found that firing in the GPi and SNr is inhibited for several hundreds of milliseconds following the end of a short, 200 Hz high-frequency train delivered through the recording electrode (e.g., on average 618 ms when stimulating in the SNr with a 0.5 s train of 4 microA pulses at 200 Hz). Inhibition duration usually increased with increasing current intensity, train frequency and generally peaked for trains of 1-2 s, while it decreased with increasing train durations. Statistical analysis with general linear models revealed a significant linear relationship between current intensity and inhibition duration in all nuclei and patient groups. There was also a significant relationship between train frequency and inhibition duration in the SNr and GPi of PD patients and between train duration and inhibition duration in the GPi of PD patients. There was no significant difference in inhibition duration across patient groups but the current threshold for inhibition was significantly different in the SNr compared to the GPi. The characteristics of the inhibition observed are consistent with stimulation-induced GABA release following activation of the GABAergic afferents in the SNr and GPi. The findings suggest that high-frequency microstimulation of the GPi and SNr depresses local neuronal activity and synaptic transmission, and such mechanisms may contribute to the therapeutic effects of DBS.

Deep brain stimulation (DBS) has been playing an increasing role in the treatment of various movement disorders with the most common being Parkinson’s disease (PD). Currently, the preferred target for treating PD motor symptoms is the subthalamic nucleus (STN). Microelectrode recordings are frequently used to aid in the determination of the optimal target for implanting the DBS electrode. Changes in cellular activity are typically used to detect the borders of the STN during microelectrode recordings. Although the dorsal border of the STN is usually clear, its ventral border with the substantia nigra pars reticulata (SNr) is sometimes more difficult to identify. Our previous studies of the effects of microstimulation in the internal globus pallidus (GPi), which is functionally similar to SNr, and STN revealed that firing in GPi but not STN neurons is readily inhibited by low current stimulation through an adjacent microelectrode. The aim of the current study was to examine and compare the aftereffects of local high-frequency microstimulation through the recording electrode on the firing of STN and SNr neurons to determine whether this might be a useful technique for differentiating STN from SNr. Neurons in the SNr and STN were identified as well isolated high-amplitude spikes and were stimulated extracellulary through the recording microelectrode with 0.5-s trains of high-frequency (200 Hz) and low current (

The design of a scalable optical local area network for multiprocessing systems is described. Each workstation has a parallel-fiber-ribbon optical link to a centralized complementary metal-oxide silicon (CMOS) switch core, implemented on a single compact printed circuit board (PCB). When the Motorola Optobus fiber technology is used, each workstation has a data bandwidth of 6.4 Gbits/s to the core. A centralized switch core interconnecting 32 workstations supports a 204-Gbit/s aggregate data bandwidth. The switch core is based on a conventional broadcast-and-select architecture, implemented with parallel CMOS integrated circuits (IC’s). The switch core scales well; by incorporation of the CMOS optoelectronic IC’s with optical input–output, the electrical core can be reduced to a single-chip optoelectronic IC with terabit capacities. A prototype of an optoelectronic switch core has been fabricated and is described. The appeal of the architecture includes its reliance on commercially available parallel-fiber technology, its reliance on the well-developed markets of local area networks and networks of workstations, and its smooth scalability from the electrical to optical domains as technology matures.

The mammalian spinal cord contains a locomotor central pattern generator (CPG) that can produce alternating rhythmic activity of flexor and extensor motoneurones in the absence of rhythmic input and proprioceptive feedback. During such fictive locomotor activity in decerebrate cats, spontaneous omissions of activity occur simultaneously in multiple agonist motoneurone pools for a number of cycles. During these 'deletions', antagonist motoneurone pools usually become tonically active but may also continue to be rhythmic. The rhythmic activity that re-emerges following a deletion is often not phase shifted. This suggests that some neuronal mechanism can maintain the locomotor period when motoneurone activity fails. To account for these observations, a simplified computational model of the spinal circuitry has been developed in which the locomotor CPG consists of two levels: a half-centre rhythm generator (RG) and a pattern formation (PF) network, with reciprocal inhibitory interactions between antagonist neural populations at each level. The model represents a network of interacting neural populations with single interneurones and motoneurones described in the Hodgkin-Huxley style. The model reproduces the range of locomotor periods and phase durations observed during real locomotion in adult cats and permits independent control of the level of motoneurone activity and of step cycle timing. By altering the excitability of neural populations within the PF network, the model can reproduce deletions in which motoneurone activity fails but the phase of locomotor oscillations is maintained. The model also suggests criteria for the functional identification of spinal interneurones involved in the mammalian locomotor pattern generation.