Radial artery vs right internal mammary artery as a second conduit during coronary artery bypass grafting.

OBJECTIVE: To compare the clinical outcomes of radial artery (RA) grafts during CABG to those of right internal mammary artery (RIMA) grafts. METHODS: This was a retrospective, single-institution cohort study of isolated CABG with multiple grafts between 2010-2022. To balance graft cohorts, propensity score matching (PSM) was performed using a 1:1 match ratio. Long-term postoperative survival was compared among RA and RIMA groups. Similarly, major adverse cardiac and cerebrovascular events (MACCE) were compared among both cohorts, with MACCE comprising death, myocardial infarction (MI), coronary revascularization, and stroke. Kaplan-Meier estimation was performed for mortality, while cumulative incidence estimation was utilized for MACCE. RESULTS: A total of 8,774 patients underwent CABG. Of those, 1,674 (19.1%) patients who underwent multiarterial CABG were included in this analysis. 326 (19.5%) patients received RA grafts and 1,348 (80.5%) received RIMA grafts. PSM yielded a cohort of 323 RA patients and 323 RIMA patients. After matching, groups were well-balanced across all baseline variables. No significant differences were observed in immediate postoperative complications or long-term survival, with 5-year survival estimates of 89.5% for the RA group vs 90.1% for the RIMA group. There was a nonsignificant trend toward a higher incidence of MACCE at 5 years in the RA group compared to the RIMA group (31.3% in the RA group vs 24.1% in the RIMA group), especially after 1-year follow-up (21.6% in the RA group vs 15.1% in the RIMA group). Specifically, for RA patients, there were higher rates of repeat revascularization in the 5-year postoperative period (14.7% in the RA group vs 5.3% in the RIMA group), particularly in the territory revascularized by the RA during the index operation (45.7% in the RA group vs 10.3% in the RIMA group). CONCLUSION: Overall, RA and RIMA secondary conduits for CABG were associated with comparable immediate postoperative complications, 5-year MACCE, and 5-year survival after PSM. RA grafting was associated with significantly higher rates of repeat coronary revascularization at 5 years, specifically in the territory revascularized by the RA during the index operation.

Hybrid integrated optical chaos circuits with optoelectronic feedback.

A chip-scale chaotic laser system with optoelectronic delayed feedback is proposed and analyzed by numerical simulation. This chip eliminates the need for bulky delay components such as long optical fibers, free propagation and external cavities, relying solely on internal devices and waveguides to achieve feedback delay. This approach simplifies integration, maintaining a compact chip size. According to the results, the chip-scale system exhibits rich dynamics, including periodicity, quasi-periodicity, and chaotic states. Chaos resembling Gaussian white noise is achieved with picosecond-level delay time, highlighting the complexity of chip-scale signals. Furthermore, time delay signature (TDS) concealment is enhanced with a short delay comparable to the inverse bandwidth τ, albeit at a cost of sacrificing chaotic signal complexity. Applying the photonic integrated circuits to practical applications, 1 Gbps back-to-back communication transmission is feasible. Results demonstrate low bit error rates (BERs) for authorizers (<10-6) and high BERs for eavesdroppers (>10-2), ensuring communication confidentiality and chaotic synchronization. Lastly, preliminary experiments validate the feasibility. Our theoretical work has demonstrated the feasibility of hybrid integrated optical chaos circuits with optoelectronic feedback based on photonic wire bonding, which can provide a stable and flexible integrated chaos source.

Investigation on the monolithically integrated chaotic optical transmitting chip based on parallel EAMs.

Chaotic optical communication ensures information security at the physical layer. However, the monolithic integration of lasers and lithium niobate Mach-Zehnder modulators remains a challenge, limiting the progress of integrated chaotic optical communication systems based on an electro-optic feedback. Here, we propose the monolithically integrated chaotic optical transmitting chip based on the parallel EAMs and validate its performance from the perspectives of phase portraits, fast Fourier transform (FFT), probability density function (PDF), largest Lyapunov exponents, and bifurcation. The results demonstrate the feasibility of the chip, which is beneficial for the miniaturization and integration of the system.

Splenectomy as a part of cytoreductive surgery in ovarian cancer: systematic review and meta-analysis.

OBJECTIVE: The role of splenectomy on cytoreductive surgery in patients with ovarian cancer remains controversial. We conducted this meta-analysis to evaluate the safety and impact of survival outcome of splenectomy in patients with ovarian cancer. METHODS: In this meta-analysis we analyzed studies published in PubMed, Embase, Cochrane Central Register of Controlled Trials (CENTRAL), International Clinical Trials Registry Platform (ICTRP), and Clinical Trials. gov that appeared in our search from inception to November 10, 2023. RESULT: This meta-analysis included 10 studies, totaling 6297 patients, comprising one prospective and nine retrospective analyses. The results indicated no significant disparity in overall survival and mortality (OR 1.14, 95% CI 0.69 to 1.87, p=0.62) between the splenectomy cohort and the no splenectomy (required) cohort. Furthermore, relative to the no splenectomy (required) cohort, the splenectomy group showed a heightened incidence of overall post-operative complications (odds ratio (OR) 1.66, 95% CI 1.65 to 2.61, p=0.03), an extended duration of hospitalization (mean difference (MD) 2.88 days, 95% CI 2.09 to 3.67), an increased interval from surgery to the initiation of adjuvant chemotherapy (MD 4.44 days, 95% CI 2.41 to 6.07, p<0.0001), and a greater probability of undergoing reoperation (OR 4.7, 95% CI 1.91 to 11.55, p=0.0007). However, concerning the occurrence of specific post-operative complications such as anastomotic leakage (OR 0.97, 95% CI 0.33 to 2.84, p=0.95), pancreatic fistula (OR 3.25, 95% CI 0.63 to 16.7, p=0.16), abdominal abscess (OR 1.75, 95% CI 0.25 to 12.33, p=0.57), sepsis (OR 1.46, 95% CI 0.77 to 2.77, p=0.25), and thrombotic events (OR 1.82, 95% CI 0.93 to 3.57, p=0.08), no significant differences were observed between the two cohorts. CONCLUSION: Splenectomy does not impact the overall survival and mortality of patients with ovarian cancer. Thus, it can be considered an acceptably safe procedure to obtain optimal cytoreduction. However, caution should be taken when selecting patients for splenectomy because it is associated with an increased incidence of overall post-operative complications, prolonged hospital stays, delayed initiation of adjuvant chemotherapy, and an increased probability of requiring subsequent surgical interventions.

Long-term outcomes of total arch replacement with bilateral antegrade cerebral perfusion using the "arch first" approach.

OBJECTIVE: To report outcomes of total arch replacement (TAR) with hypothermic circulatory arrest and bilateral antegrade cerebral perfusion (bACP) using an "arch first" approach for acute Type A aortic dissection (ATAAD). The "arch first" approach involved revascularization of the aortic arch branch vessels with uninterrupted ACP, before lower body circulatory arrest, while the patient was cooling. METHODS: This was an observational study of aortic surgeries from 2010 to 2021. All patients who underwent TAR with bACP for ATAAD were included. Short-term and long-term outcomes were reported utilizing descriptive statistics and Kaplan-Meier survival estimation. RESULTS: A total of 215 patients were identified who underwent TAR + bACP for ATAAD. Age was 59.0 [49.0-67.0] years and 35.3% were female. 73 patients (34.0%) underwent a concomitant aortic root replacement, 188 (87.4%) had aortic cannulation, circulatory arrest time was 37.0 [26.0-52.0] minutes, and nadir temperature was 20.8 [19.4-22.5] degrees Celsius. 35 patients (16.3%) had operative mortality (STS definition), 17 (7.9%) had a new stroke, 79 (36.7%) had prolonged mechanical ventilation (>24 h), 35 (16.3%) had acute renal failure (by RIFLE criteria), and 128 (59.5%) had blood product transfusions. One-year survival was 77.1%, while 5-years survival was 67.1%. During follow-up, there were 23 (10.7%) reinterventions involving the descending thoracic aorta - either thoracic endovascular aortic repair or open thoracoabdominal aortic replacement. CONCLUSIONS: Among patients with ATAAD, short-term postoperative outcomes after TAR + bACP using the "arch first" approach are acceptable. Moreover, this operative strategy may furnish long-term durability, with a reasonably low reintervention rate and satisfactory overall survival.

The Targeted Regulation of BDUbc and BDSKL1 Enhances Resistance to Blight in Bambusa pervariabilis × Dendrocalamopsis grandis.

Arthrinium phaeospermum is the major pathogen responsible for the significant stem disease "blight" in B. pervariabilis × D. grandis. The interacting proteins of the key pathogenic factor ApCtf1ß, BDUbc and BDSKL1, have previously been obtained by two-hybrid, BiFC, GST pull-down yeast assays. However, the functions of these interacting proteins remain unknown. This study successfully obtained transgenic plants overexpressing BDUbc, BDSKL1, and BDUbc + BDSKL1 via Agrobacterium-mediated gene overexpression. qRT-PCR analysis revealed significantly increased expression levels of BDUbc and BDSKL1 in the transgenic plants. After infection with the pathogenic spore suspension, the disease incidence and severity index significantly decreased across all three transgenic plants, accompanied by a marked increase in defense enzyme levels. Notably, the co-transformed plant, OE-BDUbc + BDSKL1, demonstrated the lowest disease incidence and severity index among the transgenic variants. These results not only indicate that BDUbc and BDSKL1 are disease-resistant genes, but also that these two genes may exhibit a synergistic enhancement effect, which further improves the resistance to blight in Bambusa pervariabilis × Dendrocalamopsis grandis.

BER for a space uplink laser communication system under an actual optical distortion with a cake-cutting method.

A numerical calculating model is proposed for characterizing the BER performance of the detector working among the 2-D asymmetric distorted spot on the effects of atmospheric turbulence under weak turbulent conditions. Based on the isotropy of the beam wander effect, we introduce a beam wander vector to describe the behavior of the detector drifting among the receiving plane. Furthermore, using the cake-cutting method, the overall PDF of the light intensity is approximated by the average PDF of light intensity intercepted by the detector drifting in all different directions. The results demonstrate that the model obtains the overall PDF of the light intensity received by the detector and analyzes the BER performance of the communication system efficiently. Being an extension of the traditional 1-D calculation, our proposed model has important implications for designing the space uplink optical communication system.

Readmission with infective endocarditis within 90 days following transcatheter aortic valve implantation.

INTRODUCTION: Transcatheter aortic valve implantation (TAVI) continues to be the most common modality of treating aortic stenosis in the United States. While infective endocarditis (IE) and its outcomes have been well documented after surgical aortic valve replacement, the incidence and outcomes of early IE after TAVI have not been well described. METHODS: All patients who underwent TAVI from 2012 through 2018 were identified using the National Readmission Database. Among them, patients who underwent TAVI at the index admission and readmitted within 90 days were included. Patients who died or had IE during the index admission were excluded. Clinical outcomes were compared between patients readmitted with IE (IE group) and those without (non-IE group). RESULTS: A total of 168,283 patients were readmitted to a hospital within 90 days after TAVI. The median age of the IE group and non-IE group were 81 and 82 years old, respectively (p = 0.21). Of those, 525 (0.3%) were readmitted with IE. The median time from TAVI to readmission was 20 days. During readmissions, 11.6% of the IE group died while only 3.15% of the non-IE group experienced death (p < 0.001). The most common causative organism of IE was enterococcus (22.1%). Multivariable analysis revealed that congestive heart failure, cerebrovascular disease, dialysis, concomitant valve disease, Medicaid, and discharge to a facility were independently associated with readmission with IE within 90 days. CONCLUSION: The incidence of readmission with IE is low after TAVI. However, the mortality was markedly high during readmissions. Surgical intervention was rarely performed for IE during the first admission. Enterococcus was the most common organism observed in IE after TAVI. DISCLOSURE: IS receives institutional research support from Abbott, Atricure, cryolife, and Medtronic. None related to this manuscript. CLINICAL TRIAL REGISTRATION: Not applicable.

A Novel Risk Score to Predict Thirty-Day Readmissions after Acute Type A Aortic Dissections.

BACKGROUND: Readmissions following acute type A aortic dissections (ATAAD) are associated with potentially worse clinical outcomes and increased hospital costs. Predicting which patients are at risk for readmission may guide patient management prior to discharge. METHODS: The National Readmissions Database was utilized to identify patients treated for ATAAD between 2010 and 2018. Univariate mixed effects logistic regression was used to assess each variable. Variables were assigned risk points based off the bootstrapped (bias-corrected) odds ratio of the final variable model according to the Johnson's scoring system. A mixed effect logistic regression was run on the risk score (sum of risk points) and 30-day readmission. Calibration plots and predicted readmission curves were generated for model assessment. RESULTS: A total of 30,727 type A aortic dissections were identified. The majority of ATAAD (66%) were in men with a median age of 61 years and 30-day readmission rate of 19.4%. The risk scores ranging from -1 to 14 mapped to readmission probabilities between 3.5% and 29% for ATAAD. The predictive model showed good calibration and receiver operator characteristics with an area under the curve (AUC) of 0.81. Being a resident of the hospital state (OR: 2.01 [1.64, 2.47], p < 0.001) was the highest contributor to readmissions followed by chronic kidney disease (1.35 [1.16, 1.56], p = 0), discharge to a short-term facility (1.31 [1.09, 1.57], p = 0.003), and developing a myocardial infarction (1.20 [1.00, 1.45], p = 0.048). CONCLUSIONS: The readmission model had good predictive capability given by the large AUC. Being a resident in the State of the index admission was the most significant contributor to readmission.

Electrochemiluminescent bioassay based on Ru@Zr-BTC-MOFs nanoparticles for determination of let-7a miRNA using the hybridization chain reaction.

Carboxyl-rich tris(4,4'-dicarboxylic acid-2,2'-bipyridyl) ruthenium(II) ([Ru(dcbpy)3]2+) and 1,3,5-phenyl tricarboxylic acid (H3BTC) were used as the organic ligand to synthesize the metal-organic frameworks by a simple one-pot hydrothermal method with ZrCl4 as metal ion source. Subsequently, the excellent electrochemiluminescence (ECL) luminophore (denoted as Ru@Zr-BTC-MOFs) was obtained. The Ru@Zr-BTC-MOFs displayed outstanding ECL properties, and a sensitive ECL bioassay based on Ru@Zr-BTC-MOFs was designed for the detection of let-7a microRNA (miRNA) using hybrid chain reaction (HCR). Under the optimal experimental conditions, the proposed bioassay exhibited a good linear relationship in the range from 50.0 fM to 5.00 × 102 pM with a detection limit of 3.71 fM. Besides, the proposed sensor exhibited satisfactory performance in real samples. The recovery was 91 ~ 108%, and the relative standard deviation was less than 5.6%. It might have potential clinical applications for detecting miRNA in biomedical research and clinical diagnosis. The schematic diagram of the preparation of Ru@Zr-BTC-MOFs (a) and ECL sensor for detecting let -7a (b).

Researching pointing error effect on laser linewidth tolerance in space coherent optical communication systems.

In order to evaluate the pointing error effect on laser linewidth tolerance in a space coherent optical communication system, we derive a closed-form bit error rate (BER) model for binary phase-shift-keying (BPSK) modulation and heterodyne detection, under atmospheric turbulence, pointing error and laser phase noise. Based on the BER model, the linewidth tolerance is given, and numerical simulation is conducted. We find that laser linewidth tolerance decreases greatly with the increase of pointing error. Considering that pointing error consists of jitter and boresight, the effect of jitter and boresight are discussed separately and jointly in detail. Our results show that laser linewidth tolerance is more sensitive to the jitter variation than the boresight variation. In addition, with the increasing of the pointing error, the linewidth tolerance decreases faster under the large pointing error as compared to the case under the small pointing error. This paper is a good reference for designing space coherent optical communication systems.

Revascularization Strategies for Multivessel Coronary Artery Disease in the Elderly Population.

BACKGROUND: Prospective trials comparing coronary artery bypass grafting (CABG) with percutaneous coronary intervention (PCI) for the treatment of multivessel coronary disease (MVCAD) have included mostly younger patients. We compared treatment strategies in the elderly population. MATERIALS AND METHODS: We performed a propensity-score-matched comparison of patients ≥75 y who underwent isolated CABG or PCI for MVCAD between 2011 and 2018, excluding those with prior cardiac surgery and/or significant left main disease. The primary outcome was 5-year Kaplan Meier survival, and secondary outcomes included readmissions and major adverse cardiovascular and cerebrovascular events (MACCE). RESULTS: Propensity-matching yielded 536 patients (266 PCI and 266 CABG). Rates of complete revascularization of all stenotic lesions were higher in the CABG arm (86.8% versus 21.8%; P < 0.001). Thirty-d mortality was similar between cohorts, though PCI recipients had shorter hospital stay and greater likelihood of discharge to home. Unadjusted one- (89.1% versus 88.4%) and 5-year (73.8% versus 60.1%) survival were both higher in patients who underwent CABG (P = 0.0332). Patients undergoing CABG had reduced, but nonsignificant cumulative incidence of all-cause hospital readmission and MACCE at 5 y. Subgroup analysis of patients 80 y or older revealed similar late survival benefit with CABG when compared to PCI. Among patients undergoing CABG, there did not appear to be any 5-year benefits from multi-arterial grafting. CONCLUSIONS: Despite longer hospitalization and higher rate of nonhome discharge, CABG was associated with improved late survival over PCI in the elderly population. Cardiac surgeons should be included in the multidisciplinary evaluation of older patients with MVCAD.

Midterm Outcomes of Isolated Coronary Artery Bypass Grafting in the Setting of Moderate Ischemic Mitral Regurgitation.

INTRODUCTION: Although randomized trial data exist for 2-y outcomes comparing isolated coronary artery bypass grafting (CABG) versus CABG with concomitant mitral valve repair (CABG + MVr) for the treatment of moderate ischemic mitral regurgitation (IMR), longer term outcomes are unclear. This study evaluated the longitudinal outcomes of isolated CABG for moderate IMR. METHODS: Patients with moderate IMR undergoing isolated CABG from January 2010 to February 2018 at a single institution were included. Outcomes included longitudinal freedom from heart failure readmission, survival, rates of persistent mitral regurgitation (MR), and freedom from mitral valve reinterventions. A subanalysis was conducted comparing CABG versus CABG + MVr. Multivariable Cox regression was used for risk adjustment. RESULTS: A total of 528 patients with moderate IMR underwent isolated CABG. Postoperatively, 26% of patients had at least moderate MR at 1-mo follow-up, although at 5 y progression to severe MR was rare (2.2%) as were mitral valve reinterventions (0.2%). Survival at 30 d (95.8%), 1 y (89.6%), and 5 y (76.6%) was acceptable. Furthermore, the freedom from readmission for heart failure was also acceptable at 30 d (92.6%), 1 y (79.9%), and 5 y (65.0%) postoperatively. In a subanalysis comparing CABG versus CABG + MVr, unadjusted and risk-adjusted survival, freedom from heart failure readmissions, mitral valve reinterventions, and degrees of MR were comparable between the groups at all intervals (all P > 0.05). CONCLUSIONS: The majority of patients with moderate IMR can undergo isolated CABG with acceptable rates of heart failure readmissions, survival, progression to severe MR, and the need for subsequent mitral interventions. These data support the use of isolated CABG in patients with moderate IMR.

Charlson Comorbidity Index is Associated With Longer-Term Mortality and Re-Admissions Following Coronary Artery Bypass Grafting.

INTRODUCTION: The Charlson Comorbidity Index (CCI) is widely utilized for risk stratification by providers, payors, and administrative database researchers for non-cardiac surgical patients. CCI scores have not been validated in cardiac surgical patients. We hypothesize that the CCI will predict mid-term mortality and re-admissions, but performance may be different than purpose-built cardiac surgery risk calculators. METHODS: Patients undergoing isolated CABG between 2011 and 2017 were reviewed. Age-adjusted CCI scores were calculated based on clinical status at a time of index operation using prospectively captured data from institutional databases. Primary endpoint was 5-year mortality and 1-year re-admissions. The CCI, STS predicted mortality, and ASCERT 5-year mortality scores were compared in a sub-cohort of 500 patients. Patients underwent analysis using Cox Proportional Hazard ratios, Kaplan-Meier analysis, and ROC comparisons. RESULTS: Average CCI score for the overall population (n = 6064) was 3.40 ± 1.75. Kaplan-Meier analysis revealed significant difference in mortality stratified by CCI. Hazard ratio for 5-year mortality increased with each interval increase in CCI score value (HR 1.38 [1.33-1.43], P < 0.001), as did the risk of 1-year re-admission (HR 1.19 [1.15-1.22], P < 0.001). ROC curves for CCI, STS mortality, and ASCERT 5-year mortality risk demonstrate that all three scores are predictive at 5 y, but the ASCERT score performs best (ROC 0.76 versus 0.69, P = 0.004). CONCLUSIONS: The CCI can serve as a useful mid-term risk stratification tool in patients undergoing CABG when variables for the purpose-built STS and ASCERT scores are unavailable. However, the ASCERT score performs better at 5-year mortality calculation.

Fate of the Kidneys in Patients with Post-Operative Renal Failure After Cardiac Surgery.

BACKGROUND: This study evaluates the clinical and renal-related outcomes in patients with acute renal failure (ARF) following cardiac surgery. METHODS: Index adult cardiac operations at a single institution from 2010-2018 were reviewed. Patients requiring dialysis pre-operatively were excluded. ARF was stratified as either creatinine rise (≥3-times baseline or ≥4.0 mg/dL) or post-operative dialysis. Outcomes included mortality, rates of progression to dialysis, and renal recovery. Multivariable Cox regression was used for risk-adjustment. RESULTS: A total of 10,037 patients, including 6,275 (62.5%) isolated coronary artery bypass grafting (CABG), 2,243 (22.3%) isolated valve, and 1,519 (15.1%) CABG plus valve cases, were included. Post-operative ARF occurred in 346 (3.5%) patients, with 230 (66.5%) requiring dialysis. Survival was significantly reduced in patients with ARF at 30-days (97.9 versus 70.8%, P <0.001), 1-year (94.9 versus 48.0%, P <0.001), and 5-years (86.2 versus 38.2%, P <0.001) with more profound reductions in those requiring dialysis, findings which persisted after risk-adjustment. Progression to subsequent dialysis in the creatinine rise group was rare (n = 1). The median time to dialysis initiation in the dialysis group was 5 days (IQR 2-12 days) with a median time of dialysis dependence of 72 days (IQR 38-1229 days). Of those patients requiring postoperative dialysis, 30.9% demonstrated renal recovery. CONCLUSIONS: Post-operative ARF and in particular the need for dialysis are associated with substantial reductions in survival that persist during longitudinal follow-up. This occurs despite the finding that patients experiencing creatinine rise only rarely progress to dialysis, and that nearly one-third of patients requiring post-operative dialysis recover renal function.

Impact of ethnicity and race on outcomes after thoracic endovascular aortic repair.

INTRODUCTION: Thoracic endovascular aortic repair (TEVAR) became the standard of care for treating Type B aortic dissections and descending thoracic aortic aneurysms. We aimed to describe the racial/ethnic differences in TEVAR utilization and outcomes. METHODS: The National Inpatient Sample was reviewed for all TEVARs performed between 2010 and 2017 for Type B aortic dissection and descending thoracic aortic aneurysm (DTAA). We compared groups stratifying by their racial/ethnicity background in White, Black, Hispanic, and others. Mixed-effects logistic regression was performed to assess the relationship between race/ethnicity and the primary outcome, in-hospital mortality. RESULTS: A total of 25,260 admissions for TEVAR during 2010-2017 were identified. Of those, 52.74% (n = 13,322) were performed for aneurysm and 47.2% (n = 11,938) were performed for Type B dissection. 68.1% were White, 19.6% were Black, 5.7% Hispanic, and 6.5% were classified as others. White patients were the oldest (median age 71 years; p < .001), with TEVAR being performed electively more often for aortic aneurysm (58.8% vs. 34% vs. 48.3% vs. 48.2%; p < .001). In contrast, TEVAR was more likely urgent or emergent for Type B dissection in Black patients (65.6% vs. 41.1% vs. 51.6% vs. 51.7%; p < .001). Finally, the Black population showed a relative increase in the incidence rate of TEVAR over time. The adjusted multivariable model showed that race/ethnicity was not associated with in-hospital mortality. CONCLUSION: Although there is a differential distribution of thoracic indication and comorbidities between race/ethnicity in TEVAR, racial disparities do not appear to be associated with in-hospital mortality after adjusting for covariates.

Long-term outcomes of patients undergoing mechanical versus bioprosthetic aortic root replacement.

BACKGROUND: We evaluated the impact of valve type (mechanical vs. bioprosthetic) on survival after aortic root replacement (ARR). METHODS: In a propensity-matched analysis, we evaluated consecutive operations from 2010 to 2018. Patients were identified using a prospectively maintained institutional database. Patients with infective endocarditis were excluded. Kaplan-Meier survival estimation and multivariable Cox regression analysis were performed. Cox regression adjusted for age, sex, baseline comorbidities, and operative variables. Propensity score matching yielded 153 pairs of patients. RESULTS: A total of 893 patients were identified. We excluded 192 patients with endocarditis and evaluated 701 patients. Of these patients, 455 (64.9%) received a bioprosthetic valve, 246 (35.1%) received a mechanical valve. Median follow-up was 4.06 years. The proportion of aortic dissections and circulatory arrest as well as cardiopulmonary bypass and ischemic times were similar across groups (p = .207, p = .086, p = .668, p = .454, respectively). Operative mortality was significantly higher in the bioprosthetic valve group (7.9% vs. 2.4%, p = .004). Total length of hospital stay was longer (11.4 ± 11.0 vs. 9.5 ± 10.1, p < .001) and there was a higher proportion of prolonged postoperative ventilation >24 h (21.3% vs. 13.0%, p = .007) in the bioprosthetic group. Postoperative outcomes were similar, regarding stroke (p = .077), re-exploration for bleeding (p = .211), new dialysis requirement (p = .077), long-term bleeding complications (p = .561), and reoperations (p = .755). Mechanical valve replacement was associated with improved long-term survival (adjusted HR 0.42, 95% CI: 0.23-0.77, p = .005). CONCLUSIONS: These findings suggest that mechanical valves for ARRs may confer a survival benefit over bioprosthetic valves. Surgeon bias was likely to account for this survival advantage.

Outcomes of transcatheter aortic valve replacement at teaching versus nonteaching hospitals.

INTRODUCTION: Prior studies have demonstrated that outcomes of invasive cardiac interventions may vary by hospital teaching status and volume. As transcatheter aortic valve replacement (TAVR) rapidly expands from teaching to nonteaching hospitals across the country, the clinical impact of hospital teaching status has not been clearly established. This study aimed to compare TAVR outcomes between nonteaching and teaching hospitals. METHODS: An observational study was conducted using the Nationwide Readmission Database (NRD). Patients undergoing TAVR from 2011 to 2018 were included. Data was analyzed using multivariable logistic regression to determine outcomes of 30-day mortality and readmission between nonteaching and teaching hospitals. RESULTS: A total of 235,321 patients underwent TAVR during the study period. Patients undergoing TAVR at teaching hospitals presented with a higher frequency of baseline comorbidities compared to nonteaching hospitals. Postprocedure complications such as myocardial infarction, arrhythmia, pneumonia, acute kidney injury, sepsis, stroke, and hemorrhage occurred more often at teaching centers (p < 0.001); translating to a higher rate of in-hospital mortality (2.27% vs. 1.99%, p = 0.006) and hospital cost ($48,300 vs. $44,900, p < 0.001) in teaching versus nonteaching hospitals. After adjusting for baseline characteristics and postoperative morbidity, in-hospital mortality (p = 0.095) and readmission rate (p = 0.420) on multivariable analysis were not statistically different between centers. CONCLUSION: With the evolution and expansion of TAVR to nonteaching centers, mortality, and readmission rates are not significantly different between nonteaching and teaching hospitals. Higher unadjusted in-hospital mortality at teaching centers suggest these centers more often treat high risk patients with associated increased complications.

Geographic disparities in heart transplantation persist under the new allocation policy.

BACKGROUND: This study evaluated the impact of the 2018 heart allocation policy change on geographic disparities in United States orthotopic heart transplantation (OHT). METHODS: The United Network for Organ Sharing registry was queried to measure geographic disparity in OHT rates between pre-policy and post-policy change eras. We performed multilevel Poisson regression to measure region-level OHT rates. We derived an allocation priority-adjusted median incidence rate ratio (MIRR) for each policy era, a measure of median change in OHT rates between regions. RESULTS: 5958.78 waitlist person-years were analyzed, comprising 6596 OHT procedures (3890 pre-policy and 2706 post-policy). Median region-level OHT rate was .94 transplants/person-years before and 1.51 transplants/person-years after the policy change (P < .001). The unadjusted OHT MIRR across regions was 1.29 (95% CI 1.00-1.50) pre-policy change and 1.17 (95% CI 1.00-1.43) post-policy change, suggesting that the region-related variance in OHT rates decreased under the new allocation. After adjustment for allocation priority risk factors, the MIRR pre-policy change was 1.13 (95% CI 1.01-1.32) and post-policy change was 1.15 (95% CI 1.00-1.35). CONCLUSIONS: Geography accounts for ∼10% of the disparity among United States OHT rates. Despite broader heart sharing, the updated allocation policy did not substantially alter the existing geographic disparities among OHT recipients.

Utilization and outcomes of postcardiotomy mechanical circulatory support.

BACKGROUND: This study evaluated the utilization and outcomes of postcardiotomy mechanical circulatory support (MCS). METHODS: This was a retrospective, single institution analysis of adult cardiac surgery cases that required de novo MCS following surgery from 2011 to 2018. Patients that were bridged with MCS to surgery were excluded. The primary outcomes were early operative mortality and longitudinal survival. Secondary outcomes included postoperative complications, and 5-year all-cause readmission. RESULTS: Five hundred and thirty-three patients required de novo postcardiotomy MCS, with the most commonly performed procedure being isolated coronary artery bypass grafting (29.8%). Median cardiopulmonary bypass and cross-clamp times were 185 (IQR 123-260) min and 122 (IQR 81-179) min, respectively. A total of 442 (82.9%) of patients were supported with intra-aortic balloon pump counterpulsation, 23 (4.3%) with an Impella device, and 115 (21.6%) with extracorporeal membrane oxygenation. Three (0.6%) patients had an unplanned ventricular assist device placed. Operative mortality was 29.8%. Longitudinal survival was 56.1% and 43.0% at 1 and 5 years, respectively. Survival was lowest in those supported with ECMO and highest with those supported with an Impella (p < 0.001). Freedom from readmission was 61.4% at 5 years. Postoperative ECMO was an independent predictor of mortality (HR 5.1, 95% CI 2.0-12.9, p < 0.001), but none of the MCS types predicted long-term hospital readmission after risk adjustment. CONCLUSIONS: Postcardiotomy MCS is associated with high operative mortality. Even patients that survive to discharge have compromised longitudinal survival, with nearly only half surviving to 1 year. Close follow-up and early referral to advanced heart failure specialists may be prudent in improving these outcomes.