Neonatal heart transplantation in the United States: Trends and outcomes.

BACKGROUND: Heart transplantation in the neonatal period is associated with excellent survival. However, outcomes data are scant and have been obtained primarily from two single-center reports within the United States. We sought to analyze the outcomes of all neonatal heart transplants performed in the United States using the United Network for Organ Sharing (UNOS) dataset. METHODS: The UNOS dataset was queried for patients who underwent infant heart transplantation from 1987 to 2021. Patients were divided into two groups based on age - neonates (<=31 days), and older infants (32 days-365 days). Demographic and clinical characteristics were analyzed and compared, along with follow up survival data. RESULTS: Overall, 474 newborns have undergone heart transplantation in the United States since 1987. Freedom from death or re-transplantation for neonates was 63.5%, 58.8% and 51.6% at 5, 10, and 20 years, respectively. Patients in the newborn group had lower unadjusted survival compared to older infants (p < .001), but conditional 1-year survival was higher in neonates (p = .03). On multivariable analysis, there was no significant difference in survival between the two age groups (p = .43). Black race, congenital heart disease diagnosis, earlier surgical era, and preoperative mechanical circulatory support use were associated with lower survival among infant transplants (p < .05). CONCLUSIONS: Neonatal heart transplantation is associated with favorable long-term clinical outcomes. Neonates do not have a significant survival advantage over older infants. Widespread applicability is limited by the small number of available donors. Efforts to expand the donor pool to include non-standard donor populations ought to be considered.

Comparison of post-operative transesophageal and transthoracic echocardiogram findings following atrioventricular septal defect repair.

Success of atrioventricular septal defect repair is defined by post-operative atrioventricular valve function and presence of residual intracardiac shunting. We evaluated differences in interpretation of atrioventricular valve function and residual defects between transesophageal and transthoracic echocardiography in a contemporary cohort of infants undergoing atrioventricular septal defect repair. Among 106 patients, we identified an increase in left and right atrioventricular valve regurgitation, right atrioventricular valve inflow gradient, and increased detection rate of residual intracardiac shunting on transthoracic compared to transesophageal echocardiograms, although residual shunts identified only on transthoracic echocardiogram were not haemodynamically significant. Findings may help inform expectation of post-operative transthoracic echocardiogram findings based on intraoperative assessment.

Management of routine postoperative pain for children undergoing cardiac surgery: a Paediatric Acute Care Cardiology Collaborative Clinical Practice Guideline.

BACKGROUND: Pain following surgery for cardiac disease is ubiquitous, and optimal management is important. Despite this, there is large practice variation. To address this, the Paediatric Acute Care Cardiology Collaborative undertook the effort to create this clinical practice guideline. METHODS: A panel of experts consisting of paediatric cardiologists, advanced practice practitioners, pharmacists, a paediatric cardiothoracic surgeon, and a paediatric cardiac anaesthesiologist was convened. The literature was searched for relevant articles and Collaborative sites submitted centre-specific protocols for postoperative pain management. Using the modified Delphi technique, recommendations were generated and put through iterative Delphi rounds to achieve consensus. RESULTS: 60 recommendations achieved consensus and are included in this guideline. They address guideline use, pain assessment, general considerations, preoperative considerations, intraoperative considerations, regional anaesthesia, opioids, opioid-sparing, non-opioid medications, non-pharmaceutical pain management, and discharge considerations. CONCLUSIONS: Postoperative pain among children following cardiac surgery is currently an area of significant practice variability despite a large body of literature and the presence of centre-specific protocols. Central to the recommendations included in this guideline is the concept that ideal pain management begins with preoperative counselling and continues through to patient discharge. Overall, the quality of evidence supporting recommendations is low. There is ongoing need for research in this area, particularly in paediatric populations.

Recollective homeostasis and the immune consequences of peritransplant depletional induction therapy.

One's cellular immune repertoire is composed of lymphocytes in multiple stages of maturation - the dynamic product of their responses to antigenic challenges and the homeostatic contractions necessary to accommodate immune expansions within physiologic norms. Given that alloreactivity is predominantly a cross-reactive phenomenon that is stochastically distributed throughout the overall T-cell repertoire, one's allospecific repertoire is similarly made up of cells in a variety of differentiation states. As such, the continuous expansion and elimination of activated memory populations, producing a 'recollective homeostasis' of sorts, has the potential over time to alter the maturation state and effector composition of both ones protective and alloreactive T-cell repertoire. Importantly, a T cell's maturation state significantly influences its response to numerous immunomodulatory therapies used in organ transplantation, including depletional antibody induction. In this review, we discuss clinically utilized depletional induction strategies, how their use alters a transplant recipient's cellular immune repertoire, and how a recipient's repertoire influences the clinical effects of induction therapy.

Novel CD8 T cell alloreactivities in CCR5-deficient recipients of class II MHC disparate kidney grafts.

Recipient CD4 T regulatory cells inhibit the acute T cell-mediated rejection of renal allografts in wild-type mice. The survival of single class II MHC-disparate H-2(bm12) renal allografts was tested in B6.CCR5(-/-) recipients, which have defects in T regulatory cell activities that constrain alloimmune responses. In contrast to wild-type C57BL/6 recipients, B6.CCR5(-/-) recipients rejected the bm12 renal allografts. However, donor-reactive CD8 T cells rather than CD4 T cells were the primary effector T cells mediating rejection. The CD8 T cells induced to bm12 allografts in CCR5-deficient recipients were reactive to peptides spanning the 3 aa difference in the I-A(bm12) versus I-A(b) ß-chains presented by K(b) and D(b) class I MHC molecules. Allograft-primed CD8 T cells from CCR5-deficient allograft recipients were activated during culture either with proinflammatory cytokine-stimulated wild-type endothelial cells pulsed with the I-A(bm12) peptides or with proinflammatory cytokine-simulated bm12 endothelial cells, indicating their presentation of the I-A(bm12) ß-chain peptide/class I MHC complexes. In addition to induction by bm12 renal allografts, the I-A(bm12) ß-chain-reactive CD8 T cells were induced in CCR5-deficient, but not wild-type C57BL/6, mice by immunization with the peptides. These results reveal novel alloreactive CD8 T cell specificities in CCR5-deficient recipients of single class II MHC renal allografts that mediate rejection of the allografts.

The risk associated with concomitant procedures performed during adult congenital heart surgery.

BACKGROUND: Adult patients with CHD often require complex operations, and indications for particular aspects of the operation are sometimes unclear. The aims of our study were as follows: to characterise concomitant procedures performed during adult congenital cardiac surgery, and to better define the risk involved with performing concomitant procedures during a single operation. METHODS: We retrospectively studied 458 adult congenital cardiac surgical patients. Major procedures were characterised as aortic, mitral, pulmonary, tricuspid, septal defect, single ventricle, transplant, and others. We constructed logistic regression models to assess the risk for mortality, major adverse event, and prolonged length of stay. RESULTS: A total of 362 operations involved a single major procedure, whereas 96 involved concomitant procedures. Performing concomitant procedures increased mortality (7.3 versus 2.5%), major adverse events (21.8 versus 14.9%), and prolonged length of stay (29.2 versus 17.1%). The added risks of concomitant procedures on mortality, major adverse event, and prolonged length of stay were 2.9 (95% CI 1.0-8.5, p=0.05), 1.9 (95% CI 1.1-3.3, p=0.02), and 2.4 (95% CI 1.4-4.1, p=0.003), respectively. There were 200 patients with conotruncal anomalies who underwent pulmonary valve surgery. In this subset, the added risks of concomitant procedures in addition to pulmonary valve surgery on mortality, major adverse events, and prolonged length of stay were 6.6 (95% CI 1.2-37.3, p=0.03), 2.8 (95% CI 1.2-6.6, p=0.03), and 3.3 (95% CI 1.5-7.4, p=0.005), respectively. CONCLUSION: Concomitant procedures performed during adult congenital heart surgery increase risk. Awareness of this risk may improve surgical decision making and outcomes.

Bioprosthetic Pulmonary Valve Dysfunction in Congenital Heart Disease.

BACKGROUND: We aim to identify the incidence and timing of dysfunction and failure of stented bioprosthetic valves in the pulmonary position in congenital heart disease patients. METHODS: A total of 482 congenital heart disease patients underwent 484 stented bioprosthetic pulmonary valve implantations between 2008 and 2018. There were 164 porcine valves (Porcine) and 320 bovine pericardial valves (Pericardial) implanted. Primary endpoints were survival, valve dysfunction, and valve failure. RESULTS: Pericardial valves were implanted in older patients (22.0, interquartile range [IQR] 14-33 vs 16.0, IQR 11-23 years, P < 0.001). Five-year survival (96.7% vs 97.9%) for the Pericardial and Porcine groups, respectively, were similar, P > 0.05. Forty-six (34%) Porcine and 75 (27%) Pericardial group patients met criteria for valve dysfunction at a median echocardiographic follow-up time of 7.43 years (IQR 4.1-9.5 years) and 3.26 years (IQR 1.7-4.7 years), respectively. More Pericardial group patients suffered from at least mild late PR while late median peak gradient was higher in the Porcine group, P < .001 for both. Risk factors for valve dysfunction included decreasing patient age for the entire cohort (hazard ratio [HR] 1.02, 95% confidence interval [CI] 1.00-1.04, P = .015) and lack of anticoagulation at discharge for the Porcine group (HR 3.06, 95% CI 1.03-9.10, P = .044) but not the Pericardial group. Five-year cumulative incidence of dysfunction was 39% for the Pericardial group and 17% for the Porcine group. CONCLUSIONS: Porcine stented and bovine pericardial stented valves can be implanted in the pulmonary position in all age groups safely. However, despite similar rates of valve failure, bovine pericardial stented valves have a higher incidence of valve dysfunction at mid-term follow-up.

CXC chemokine ligand (CXCL) 9 and CXCL10 are antagonistic costimulation molecules during the priming of alloreactive T cell effectors.

Donor Ag-reactive CD4 and CD8 T cell production of IFN-gamma is a principal effector mechanism promoting tissue injury during allograft rejection. The CXCR3-binding chemokines CXCL9 and CXCL10 recruit donor-reactive T cells to the allograft, but their role during the priming of donor-reactive T cells to effector function is unknown. Using a murine model of MHC-mismatched cardiac transplantation, we investigated the influence of CXCL9 and CXCL10 during donor-reactive T cell priming. In allograft recipient spleens, CXCL9 and CXCL10 were expressed as early as 24 h posttransplant and increased with similar kinetics, concurrently with CXCR3 expression on T cells. CXCL9, but not CXCL10, expression required NK cell production of IFN-gamma. The absence of CXCL9 in donor allografts, recipients, or both significantly decreased the frequency of donor-reactive CD8 T cells producing IFN-gamma and increased the frequency of donor-reactive CD8 T cells producing IL-17A. In contrast, the absence of CXCL10 increased the frequency of IFN-gamma-producing CD8 T cells in a CXCL9-dependent manner. These data provide novel evidence that donor-reactive CD8 T cells use the CXCR3 chemokine axis as a costimulation pathway during priming to allografts where CXCL9 promotes the development of IFN-gamma-producing CD8 T cells, and CXCL10 antagonizes this skewing.

Unraveling the impact of time-dependent perioperative variables on 30-day readmission after coronary artery bypass surgery.

OBJECTIVES: Readmission within 30 days of discharge after coronary artery bypass grafting is a measure of quality and a driver of cost in health care. Traditional predictive models use time-independent variables. We developed a new model to predict time to readmission after coronary artery bypass grafting using both time-independent and time-dependent preoperative and perioperative data. METHODS: Adults surviving to discharge after isolated coronary artery bypass grafting at a multi-hospital academic health system from January 2017 to September 2018 were included in this study. Two distinct data sources were used: the institutional cardiac surgical database and the clinical data warehouse, which provided more granular data points for each patient. Patients were divided into training and validation sets in an 80:20 ratio. We evaluated 82 potential risk factors using Cox survival regression and machine learning techniques. The area under the receiver operating characteristic curve was used to estimate model predictive accuracy. RESULTS: We trained the model with 21 variables that scored a P value of less than .05 in the univariable analysis. The multivariable model determined 16 significant risk factors, and 6 of them were time-dependent. These included preoperative hemoglobin a1c level, preoperative creatinine, preoperative hematocrit, intraoperative hemoglobin, postoperative creatinine, and postoperative hemoglobin. Area under the receiver operating characteristic values were 0.906 and 0.868 for training and validation sets, respectively. CONCLUSIONS: Time-dependent perioperative variables in an isolated coronary artery bypass grafting cohort provided better predictive ability to a readmission model. This study was unique in the inclusion of time-dependent covariates in the predictive model for readmission after discharge after coronary artery bypass grafting.

Cardiac surgery in children with trisomy 13 or trisomy 18: How safe is it?

Objective: Surgery for heart defects in children with trisomy 13 or 18 is controversial. We analyzed our 20-year experience. Methods: Since 2002, we performed 21 operations in 19 children with trisomy 13 (n = 8) or trisomy 18 (n = 11). Age at operation was 4 days to 12 years (median, 154 days). Principal diagnosis was ventricular septal defect in 10 patients, tetralogy of Fallot in 7 patients, arch hypoplasia in 1 patient, and patent ductus arteriosus in 1 patient. Results: The initial operation was ventricular septal defect closure in 9 patients, tetralogy of Fallot repair in 7 patients, pulmonary artery banding in 1 patient, patent ductus arteriosus ligation in 1 patient, and aortic arch/coarctation repair in 1 patient. There were no operative or hospital deaths. Median postoperative intensive care and hospital stays were 189 hours (interquartile range, 70-548) and 14 days (interquartile range, 8.0-37.0), respectively, compared with median hospital stays in our center for ventricular septal defect repair of 4.0 days and tetralogy of Fallot repair of 5.0 days. On median follow-up of 17.4 months (interquartile range, 6.0-68), 1 patient was lost to follow-up after 5 months. Two patients had reoperation without mortality. There have been 5 late deaths (4 with trisomy 18, 1 with trisomy 13) predominately due to respiratory failure from 4 months to 9.4 years postoperatively. Five-year survival was 66.6% compared with 24% in a group of unoperated patients with trisomy 13 or 18. Conclusions: Cardiac operation with an emphasis on complete repair can be performed safely in carefully selected children with trisomy 13 or trisomy 18. Hospital resource use measured by postoperative intensive care and hospital stays is considerably greater compared with nontrisomy 13 and 18.

Monokine induced by interferon-gamma (MIG/CXCL9) is derived from both donor and recipient sources during rejection of class II major histocompatibility complex disparate skin allografts.

Chemokines, including monokine induced by interferon-gamma (Mig/CXCL9), are produced both in allografts and during the direct T-cell infiltration that mediates graft rejection. Neither the specific production nor contribution of allograft donor versus recipient Mig in allograft rejection is currently known. C57BL/6 mice with a targeted deletion in the Mig gene were used as both skin allograft donors and recipients in a class II major histocompatibility complex-mismatched graft model to test the requirement for donor- versus recipient-derived Mig for acute rejection. B6.Mig(-/-) allografts had a 10-day prolonged survival in B6.H-2(bm12) recipients when compared with wild-type C57BL/6 allograft donors, and B6.H-2(bm12) skin allografts had a 5-day prolonged survival in B6.Mig(-/-) versus wild-type recipients. Transplantation of B6.Mig(-/-) skin grafts onto B6.H-2(bm12).Mig(-/-) recipients resulted in further prolonged allograft survival with more than 30% of the grafts surviving longer than 60 days. Prolonged allograft survival was also associated with delayed cellular infiltration into grafts but not with altered T-cell proliferative responses to donor stimulators. Immunohistochemical staining of allograft sections indicated that Mig is produced by both donor- and recipient-derived sources, but Mig from each of these sources appeared in different areas of the allograft tissue. These results therefore demonstrate the synergy of donor- and recipient-derived Mig in promoting T-cell infiltration into allografts.

CD4 T cell-mediated rejection of cardiac allografts in B cell-deficient mice.

CD4 T cell-dependent mechanisms promoting allograft rejection include expression of inflammatory functions within the graft and the provision of help for donor-reactive CD8 T cell and Ab responses. These studies tested CD4 T cell-mediated rejection of MHC-mismatched cardiac allografts in the absence of both CD8 T and B lymphocytes. Whereas wild-type C57BL/6 recipients depleted of CD8 T cells rejected A/J cardiac grafts within 10 days, allografts were not rejected in B cell-deficient B6.muMT(-/-) recipients depleted of CD8 T cells. Isolated wild-type C57BL/6 and B6.muMT(-/-) CD4 T cells had nearly equivalent in vivo alloreactive proliferative responses. CD4 T cell numbers in B6.muMT(-/-) spleens were 10% of that in wild-type mice but were only slightly decreased in peripheral lymph nodes. CD8 T cell depletion did not abrogate B6.muMT(-/-) mice rejection of A/J skin allografts and this rejection rendered these recipients able to reject A/J cardiac allografts. Redirection of the alloimmune response to the lymph nodes by splenectomy conferred the ability of B6.muMT(-/-) CD4 T cells to reject cardiac allografts. These results indicate that the low number of splenic CD4 T cells in B6.muMT(-/-) mice underlies the inability to reject cardiac allografts and this inability is overcome by diverting the CD4 T cell response to the peripheral lymph nodes.

Management outcomes of primary pulmonary vein stenosis.

OBJECTIVES: Primary pulmonary vein stenosis (PPVS) is increasingly diagnosed in children with no prior pulmonary vein intervention history, and management is challenging. We describe characteristics of patients who underwent surgical repair of PPVS at our center, and examine factors associated with treatment failures. METHODS: A retrospective review of all patients who underwent surgical intervention for PPVS (2002-2016) was completed. Patients who had undergone prior cardiac surgery involving the pulmonary veins or atrial switch were excluded. Regression analyses were performed to examine characteristics, PPVS features, including severity score, and surgical details associated with treatment failures. RESULTS: Thirty-four children underwent initial surgical intervention for PPVS. Median age was 8.9 months (interquartile range, 5.9-18.4 months). Most patients (n = 31; 91%) had unilateral pulmonary vein involvement and the median PPVS severity score was 3.5 (interquartile range, 3-5). On competing risk analysis, 1 year following surgical repair, 9% of patients had died, 14% had undergone reintervention, and 77% were alive without reintervention; at 5 years the numbers were 9%, 30%, and 61%, respectively. Factors associated with mortality included bilateral disease and PPVS severity score >6. Bilateral disease and PPVS severity score >5 were associated with reintervention risk. CONCLUSIONS: Multidisciplinary management strategy is required for PPVS. Despite satisfactory early repair, patients continue to be at risk for recurrence and subsequent mortality, especially those with extensive primary involvement. The disappointing results underscore the need for multi-institutional collaborations to better understand this complex disease, establish management and follow-up protocols, and explore investigational treatment modalities that could modify the unfavorable outcome of this uncommon and challenging disease.

Thoracoabdominal aortic aneurysm repair: open, endovascular, or hybrid?

Successful repair of complex thoracoabdominal aortic aneurysms requires careful surgical planning based on anatomic and patient considerations. Not only are surgical considerations key, but also post-operative care, regardless of surgical approach, can dramatically impact both short- and long-term outcomes. While open repair has been the gold standard for decades, the technical challenges associated with operative repair, a specialty approach requisite for good outcomes, and the unique challenges in the post-operative care of these patients have given providers pause when considering operative intervention. The relatively recent development of elegant endovascular and hybrid approaches to this problem has shown improved short-term morbidity and reasonable durability. Here, we discuss these three techniques for correction of complex thoracoabdominal aortic aneurysms to provide some guidance for optimization of outcomes based on individual patient anatomy and comorbid conditions.

Durability and safety of David V valve-sparing root replacement in acute type A aortic dissection.

BACKGROUND: Valve-sparing root replacement (VSRR) is an attractive option in type A aortic dissection (TAAD) repair for a young patient with normal cusp anatomy, but conventional root replacement using a composite valved-conduit (ROOT) remains the gold standard in this emergent clinical setting. We examine the long-term safety and durability of the David V VSRR compared with ROOT in TAAD repair. METHODS: From March 2004 to April 2017, 136 patients underwent repair of acute TAAD using either ROOT (n = 77; 56.6%) or VSRR (n = 59; 43.4%). Annual echocardiograms were performed for follow-up in VSRR patients. Univariable regression, Kaplan-Meier, and competing risk analyses were performed. RESULTS: Preoperative characteristics were similar between groups, except that VSRR patients were younger (mean age 43.5 ± 11.4 years VSRR vs 50.4 ± 3.0 years ROOT; P = .001). Both groups had similar rates of preoperative malperfusion or shock (29.3% VSRR vs 37.0% ROOT; P = .35) and ≥3+ aortic insufficiency (63% VSRR vs 76.8% ROOT). Thirty-day mortality in the VSRR group was 2/59 (3.4%) and 11/77 in the ROOT group (14.3%; P < .001). All-cause survival at 9 years was 92% (VSRR) and 59% (ROOT; P = .002). The incidence of aortic reintervention was similar between groups (20%-23% at 5 years; P = .81). At 9 years of follow-up, 5/52 (9.6%) VSRR patients had ≥2+ aortic insufficiency, and 1 patient required valve reintervention. CONCLUSIONS: In highly-selected patients, the David V VSRR provides a safe repair of acute TAAD with concomitant root pathology and valve insufficiency. In our center, the incidence of valve-related reintervention at long-term follow-up is low after emergent repair.

Predicted Risk of Mortality Score predicts 30-day readmission after coronary artery bypass grafting.

OBJECTIVE: Quality metrics and reimbursement models focus on 30-day readmission rates after coronary artery bypass grafting (CABG). Certain preoperative variables are associated with higher rates of readmission. The purpose of this study was to determine whether STS Predicted Risk of Mortality (PROM) scores predict 30-day readmission following CABG. METHODS: A retrospective review of all patients undergoing isolated CABG between 2002 and 2017 at a US academic institution was performed. Logistic regression analysis was used to determine the association between PROM and 30-day readmission, and the area under the receiver-operator curve (ROC) was calculated to estimate predictive accuracy. RESULTS: During the study period, 21,719 patients underwent CABG and 2,023 (9.2%) were readmitted within 30 days. Readmitted patients were sicker with higher rates of comorbid conditions and higher STS PROM scores (1.03% vs 1.42%, GMR 1.33, CI 1.27-1.38, p < 0.0001). Median time to readmission was 8 days (IQR 4-15) with length of stay 5 days (4-6). By PROM quintile, higher PROM scores were associated with increased odds of readmission. PROM-adjusted 30-day mortality was higher in the readmitted group (1.04% vs 0.21%, OR 4.53, CI 2.67-7.69, p < 0.001), and mid-term survival was worse as well. PROM alone was a modest predictor of readmission (area under ROC 0.59, CI 0.57-0.60) compared to insurance status (0.55, 0.53-0.56), ejection fraction (0.52, 0.50-0.54), and history of heart failure (0.51, 0.50-0.52). CONCLUSION: STS PROM scores are associated with increased risk of readmission following CABG.

Adult Congenital Cardiac Care.

BACKGROUND: The Adult Congenital Heart Association (ACHA) is dedicated to supporting patients with congenital heart disease. To guide patients to qualified providers and programs, it maintains a publicly accessible directory of dedicated adult congenital cardiac programs. We analyzed the directory in 2006 and 2015, aiming to evaluate the growth of the directory as a whole and to evaluate the growth of individual programs within the directory. We also hope this raises awareness of the growing opportunities that exist in adult congenital cardiology and cardiac surgery. METHODS: Data in the directory are self-reported. Only data from US programs were collected and analyzed. RESULTS: By the end of 2015, compared to 2006, there were more programs reporting to the directory in more states (107 programs across 42 states vs 57 programs across 33 states), with higher overall clinical volume (591 vs 164 half-day clinics per week, 96,611 vs 34,446 patient visits). On average, each program was busier (5 vs 2 half-day clinics per week per program). Over the time period, the number of reported annual operations performed nearly doubled (4,346 operations by 210 surgeons vs 2,461 operations by 125 surgeons). Access to ancillary services including specific clinical diagnostic and therapeutic services also expanded. CONCLUSION: Between 2006 and 2015, the clinical directory and the individual programs have grown. Current directory data may provide benchmarks for staffing and services for newly emerging and existing programs. Verifying the accuracy of the information and inclusion of all programs will be important in the future.

Hybrid coronary revascularization versus coronary artery bypass surgery with bilateral or single internal mammary artery grafts.

OBJECTIVE: Hybrid coronary revascularization (HCR) combines minimally invasive left internal mammary artery (LIMA)-left anterior descending artery (LAD) bypass with percutaneous intervention of non-LAD vessels. The purpose of this study was to compare outcomes of HCR to conventional coronary artery bypass graft (CABG) surgery with single internal mammary artery (SIMA) or bilateral internal mammary artery (BIMA) grafting. METHODS: Between October 2003 and September 2013, 306 consecutive patients who underwent HCR were compared with 8254 patients who underwent CABG with SIMA (7381; 89.4%) or BIMA (873; 10.6%) at a US academic center. The primary outcome was a composite of 30-day death, myocardial infarction, and stroke (major cerebrovascular and cardiac event [MACCE]). In addition to multiple logistic and linear regression analysis, a propensity score-matched analysis was used to compare HCR with SIMA and with BIMA. RESULTS: The Society of Thoracic Surgeons-predicted risk of mortality was 1.6% for HCR, 2.1% for SIMA, and 1.1% for BIMA (P < .001). Factors associated with HCR use were older age, lower body mass index, history of percutaneous coronary intervention, and 2-vessel disease. In propensity-matched groups, 30-day MACCE rates were comparable (3.3% for HCR vs 1.3% for BIMA [odds ratio (OR), 2.50; P = .12] and vs 3.6% for SIMA [OR, 1.00; P = 1.00]). In-hospital complications were lower after HCR versus SIMA or BIMA (OR, 0.59; P = .033 and OR, 0.55; P = .015, respectively), as was the need for blood transfusion (OR, 0.44; P < .001 and OR, 0.57; P < .001). HCR was associated with shorter hospital stay compared with SIMA (OR, 1.28; P = .038) or BIMA (OR, 1.40; P = .006). No survival difference between matched groups was found at midterm follow-up (HCR vs SIMA: hazard ratio [HR], 0.66; 95% confidence interval [CI], 0.32-1.38; P = .66; HCR vs BIMA: HR, 1.05; 95% CI, 0.48-2.29; P = .91). CONCLUSIONS: HCR may represent a safe, less invasive alternative to conventional CABG in carefully selected patients, with similar short-term and midterm outcomes as CABG performed with either SIMA or BIMA grafting.