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.

Surgeon and Hospital Factors Associated With Outcomes in the New York State Database.

INTRODUCTION: We sought to explore the relationship between various surgeon-related and hospital-level characteristics and clinical outcomes among patients requiring cardiac surgery. METHODS: We searched the New York State Cardiac Data Reporting System for all coronary artery bypass grafting (CABG) and valve cases between 2015 and 2017. The data were analyzed without dichotomization. RESULTS: Among CABG/valve surgeons, case volume was positively correlated with years in practice (P = 0.002) and negatively correlated with risk-adjusted mortality ratio (P = 0.014). For CABG and CABG/valve surgeons, our results showed a negative association between teaching status and case volume (P = 0.002, P = 0.018). Among CABG surgeons, hospital teaching status and presence of cardiothoracic surgery residency were inversely associated with risk-adjusted mortality ratio (P = 0.006, P = 0.029). CONCLUSIONS: There is a complex relationship between case volume, teaching status, and surgical outcomes suggesting that balance between academics and volume is needed.

Outcomes of outflow graft stenting in HeartMate 3 left ventricular assist devices: A systematic review and individual patient data meta-analysis.

PURPOSE: LVAD outflow graft stenosis continues to remain prevalent with a high complication rate. We sought to pool the existing evidence on indications, utilization patterns, and outcomes of transcatheter interventions for outflow graft stenosis in the HeartMate 3 LVAD. METHODS: An electronic search was performed to identify all studies in the English literature reporting on HeartMate 3 LVAD outflow graft stenting. Patient-level data were extracted for analysis. RESULTS: Thirteen published reports and one unpublished case comprising a total of 28 patients were included. Median patient age was 68.5 years [Interquartile range: 58, 71] and 25.9% (7/27) were female. Dyspnea [60.7% (17/28)] was the most common presenting symptom. Low flow alarms were present in 60% (15/25) of patients. Findings included external compression [35.7% (10/28)], graft twist [21.4% (6/28)], graft twist and external compression [14.3% (4.28)], intraluminal thrombus [10.7% (3/28)], graft twist and intraluminal thrombus [3.6% (1/28)], and pseudoaneurysm of outflow graft [3.6% (1/28)]. Median time from LVAD implantation to stenting was 2.1 years [1.4, 3]. Immediate flow normalization after stenting was observed in 85.7% (24/28). The 30-day mortality was 12% (3/25). Overall mortality was 12% (3/25) at a median follow-up of 3.9 months [1, 17]. CONCLUSION: Outflow graft stenting in the HeartMate 3 LVAD appears to be a reasonable treatment option for outflow graft stenosis, with low overall rates of complications and mortality. Further refinement of indications and approaches may improve outcomes.

The impact of the OPTN policy change on patients with a durable left ventricular assist device and chronic kidney disease: Analysis of the UNOS database.

BACKGROUND: The Organ Procurement and Transplantation Network (OPTN) implemented modifications in 2018 to the adult heart transplant allocation system to better stratify the most medically urgent transplant candidates. We evaluated the impact of these changes on patients supported by a durable left ventricular assist device (LVAD) with chronic kidney disease (CKD). OBJECTIVE: To evaluate the impact of the OPTN policy change on patients supported by durable left ventricular assist devices (LVAD) with chronic kidney disease (CKD). METHODS: We performed an analysis of patients from the United Network of Organ Sharing Database supported by durable LVAD listed for a heart transplant (HT) between October 17, 2016 and September 30, 2021. Patients were divided into two groups: pre- and postpolicy, depending on whether they were listed on or prior to October 17, 2018. Patients who were on dialysis prior to surgery or discharge were excluded from the analysis. Patients with simultaneous heart and kidney transplants were excluded. Patients who were listed for transplant prepolicy change but transplanted postpolicy change were excluded. This cohort was then subdivided into degrees of CKD based on estimated glomerular filtration rate (eGFR), which resulted in 678 patients (23.7%) in Stage 1 (GFR ≥89.499) (Prepolicy: 345, Postpolicy: 333), 1233 (43.1%) in Stage 2 (89.499 > GFR ≥ 59.499) (Prepolicy: 618, Postpolicy: 615), 613 (21.4%) in Stage 3a (59.499 > GFR ≥ 44.499) (Prepolicy: 291, Postpolicy: 322), 294 (10.3%) in Stage 3b (44.499 > GFR ≥ 29.499) (Prepolicy: 143, Postpolicy: 151), 36 (1.3%) in Stage 4 (29.499 > GFR ≥ 15) (Prepolicy: 21, Postpolicy: 15), and 9 (0.3%) in Stage 5 (15 > GFR) (Prepolicy: 4, Postpolicy: 5). The primary outcome was 1-year and 2-year post-HT survival. RESULTS: There were 2863 patients who met the study criteria (1422 prepolicy, 1441 postpolicy). Overall survival, regardless of CKD stage, was lower following the policy change (p < 0.01). There was a similar risk of primary graft failure (PGF) in the pre- and postpolicy period (1.8% vs. 1.2%, p = 0.26). 1-year overall survival was 93% (91, 94) and 89% (87, 91) in the pre- and postpolicy periods, respectively. 2-year overall survival was 89% (88, 91) and 85% (82, 87) in the pre- and postpolicy periods, respectively. For CKD Stages 1, 2, 3a, 3b, 4, and 5, 1 -year survival was 93% (91, 95), 92% (90,93), 89% (86, 91), 89% (86, 93), 80% (68, 94), and 100% (100, 100), respectively. For CKD Stages 1, 2, 3a, 3b, 4, and 5, 2-year survival was 91% (88, 93), 88% (86, 90), 84% (81, 88), 84% (80, 89), 73% (59, 90), and 100% (100, 100), respectively. Patients with CKD 1 and 2 had better survival compared to those with CKD 3 (p < 0.01) and CKD 4 and 5 (p = 0.03) in the pre- and postpolicy periods. Patients with CKD 3 did not have a survival advantage over those with CKD 4 and 5 (p = 0.25). On cox regression analysis, advancing degrees of CKD were associated with an increased risk of mortality. CONCLUSIONS: Patients with LVAD support had decreased overall survival after the OPTN policy change. Patients with more advanced CKD had lower survival than patients without advanced CKD, though they were not impacted by the OPTN policy change.

Predicted heart mass based on ideal body weight for donor-to-recipient size matching.

BACKGROUND: Predicted heart mass (PHM) is a commonly used tool for donor-to-recipient size matching. However, incorporating body weight as part of PHM can be considered problematic given its high variability, and low metabolic nature of fat. We sought to assess whether substituting the actual donor and recipient weight with the ideal body weight (IBW) would affect the association of donor-to-recipient PHM ratio with 1-year and overall survival after heart transplantation. METHODS: The United Network for Organ Sharing (UNOS) database was queried for adult patients who received a primary heart transplant between January 2000 and September 2021. RESULTS: Both PHM and ideal PHM (IPHM) ratios were associated with one-year (PHM: p = .003; IPHM: p = .0007) and overall (PHM: p = .02; IPHM: p = .02) survival. In the continuous analysis with restricted cubic splines, both PHM (p = .0003) and IPHM (p = .00001) were associated with relative hazards of death. CONCLUSION: IPHM is significantly associated with post-transplant survival and may be a useful compliment to PHM.

The NASA artificial heart driver: A pneumatic power source developed for Willem Kolff's artificial heart program.

The sprint to create a viable, implantable heart replacement device started in the 1950s, with current technologies still lacking a permanent solution. Early development of artificial hearts was littered with obstacles related to the power source. A pneumatic driver suggested and developed by NASA aimed to discover a more suitable pressure curve through offering highly manipulable parameters, but also enable automatic regulation of hemodynamics. While improved electric function waveforms were identified, the driver was ultimately abandoned due to minimal clinical applicability and an incomplete understanding of cardiovascular physiology. The opportunity for further waveform studies was simultaneously lost.

Utilization and outcomes of V-AV ECMO: A systematic review and meta-analysis.

BACKGROUND: Veno-arterial-venous extracorporeal membrane oxygenation (V-AV ECMO) is a less commonly used configuration of ECMO. We sought to understand the indications, utilization patterns, and outcomes of V-AV ECMO by quantitatively pooling the existing evidence from the literature. METHODS: Electronic search was performed to identify all relevant studies reporting V-AV ECMO usage. Five studies comprising 77 patients were selected and cohort-level data were extracted for further analysis. RESULTS: Mean patient age was 61 (95% CI: 55.2, 66.5) years and 30% (23/77) were female. The majority of cases [91% (70/77)] were transitioned to V-AV ECMO from another pre-existing ECMO configuration: V-A ECMO in 55% (42/77) vs. V-V ECMO in 36% (28/77), p = 0.04. Only 9% (7/77) of cases were directly placed on V-AV ECMO. The mean duration of hospital stay was 42.3 (95% CI: 10.5, 74.2) days, while ICU mortality was 46% (29, 64). Transition to durable left ventricular assist device was performed in 3% (2/64) of patients, while 3% (2/64) underwent heart transplantation. V-AV ECMO was successfully weaned to explantation in 33% (21/64) of patients. CONCLUSION: V-AV ECMO is a viable option for optimizing cardiopulmonary support in selected patients. Survival to weaning or bridging therapy appears comparable to more common ECMO configurations.

Microaxial circulatory support for percutaneous coronary intervention: A systematic review and meta-analysis.

BACKGROUND: Microaxial circulatory support devices have been used to support patients treated with percutaneous coronary intervention (PCI) for acute myocardial infarction complicated by cardiogenic shock (AMICS). The purpose of this systematic review and meta-analysis was to pool and analyze the existing evidence on the baseline characteristics, periprocedural data, and outcomes of microaxial support before and after PCI in AMICS. METHODS: An electronic database search was performed to identify all cohort studies on Impella and PCI for cardiogenic shock in the English language. A total of five articles comprising 543 patients were included. These patients received microaxial support either before (pre-PCI) or after (post-PCI) undergoing PCI. Comparative analyses were done between both groups. RESULTS: The mean patient age was 66 years [95% Confidence Interval (58-74)], and 22% (89/396) of patients were female. ST-elevation myocardial infarctions (MI) comprised 64% (44-80) of MIs and 50% (44-56) of MIs involved the left anterior descending artery. The mean number of diseased vessels was 2.21 (1.62-2.80). The mean left ventricular ejection fraction was 31% (23.4-38.6). The mean arterial pressure was 66.3 mm Hg (54.1-78.5). Mean serum lactate [6.1 mmol/L (3.3-8.9)] and serum creatinine [1.4 mg/dl (1.0-1.7)] were similar between groups. 30-day mortality was lower in the pre-PCI group [41% (34%-49%)] compared to the post-PCI group [61% (42%-77%), p < 0.01]. Pooled Kaplan-Meier analysis showed better early survival in the pre-PCI group (p < 0.001). CONCLUSION: Patients presenting with AMICS were similar at baseline in both pre-PCI and post-PCI groups. Nevertheless, pre-PCI group showed better early survival compared to post-PCI group.

Utility of Recipient Cardiothoracic Ratio in Predicting Delayed Chest Closure after Heart Transplantation.

BACKGROUND: Predicted cardiac mass (PCM) has been well validated for size matching donor hearts to heart transplantation recipients. We hypothesized that cardiothoracic ratio (CTR) could be reflective of recipient-specific limits of oversizing, and sought to determine the utility of donor to recipient PCM ratio (PCMR) and CTR in predicting delayed chest closure after heart transplantation. METHODS: A retrospective review of prospectively collected data on 38 consecutive heart transplantations performed at our institution from 2017 to 2020 was performed. Donor and recipient PCM were estimated using Multi-Ethnic Study of Atherosclerosis predictive models. Receiver operating characteristic analysis was performed to determine the discriminatory power of the ratio of PCMR to CTR in predicting delayed sternal closure. RESULTS: Of the 38 patients, 71.1% (27/38) were male and the median age at transplantation was 58 (interquartile range [IQR]: 47-62) years. Ischemic cardiomyopathy was present in 31.6% of recipients (12/38). Median recipient CTR was 0.63 [IQR: 0.59-0.66]. Median donor to recipient PCMR was 1.07 [IQR: 0.96-1.19], which indicated 7% oversizing. Thirteen out of 38 (34.2%) underwent delayed sternal closure. Primary graft dysfunction occurred in 15.8% (6/38). PCMR/CTR showed good discriminatory power in predicting delayed sternal closure [area under the curve: 80.4% (65.3-95.6%)]. PCMR/CTR cut-off of 1.7 offered the best trade-off between the sensitivity (69.6%) and specificity (91.7%). CONCLUSION: CTR could be helpful in guiding the recipient-specific extent of oversizing donor hearts. Maintaining the ratio of PCMR to CTR below 1.7 could avoid excessive oversizing of the donor heart.

Association of Heart Transplant Volume with Presence of Lung Transplant Programs and Heart Transplant's SRTR One-year Survival Rating.

BACKGROUND: Several factors affect heart transplant (HTx) and lung transplant (LTx) program outcomes. Variabilities in institutional and community characteristics have been shown to influence survival. At present, half of HTx centers in the United States do not possess a concomitant LTx program. This study sought to better understand the characteristics of HTx with and without LTx programs. METHODS: Nationwide transplant data were collected from the Scientific Registry of Transplant Recipients (SRTR) in August 2020. SRTR star rating ranges from tier 1 (lowest) to tier 5 (highest). HTx volumes and SRTR star ratings for survival were compared between the centers with heart-only (H0) programs and the centers with heart-lung (HL) programs. RESULTS: SRTR star ratings were available for 117 transplant centers with one or more HTx reported. The median number of HTx performed over 1 year was 16 (interquartile range [IQR]: 2-29). The number of HL centers (n = 67, 57.3%) were comparable to H0 centers (n = 50, 42.7%; p = 0.14). The HTx volume at the HL centers (28 [IQR: 17-41]) exceeded the HTx volume at the H0 centers (13 [IQR: 9-23]; p < 0.01), but were comparable to the LTx volume at the HL centers (31 [IQR: 16-46]; p = 0.25). The median HTx one-year survival rating was 3 (IQR: 2-4) at both the H0 and HL centers (p = 0.85). The HTx and LTx volumes were positively associated with the respective 1-year survivals (p < 0.01). CONCLUSION: While the presence of an LTx program is not directly associated with HTx survival, it has a positive association with the HTx volume. The HTx and LTx volumes are positively associated with the 1-year survival.

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.

Cardiac transplantation after heparin-induced thrombocytopenia: A systematic review.

PURPOSE: Heparin-induced thrombocytopenia (HIT) presents a unique challenge in patients requiring orthotopic heart transplantation (OHT). We sought to pool the existing evidence in a systematic review. METHODS: Electronic search was performed to identify all relevant studies on OHT in patients with HIT. Patient-level data for 33 patients from 21 studies were extracted for statistical analysis. RESULTS: Median patient age was 51 [IQR 41, 55] years, with 75.8% (25/33) males. All patients had a clinical diagnosis of HIT, and anti-PF4/Heparin antibodies were positive in 87.9% (29/33). Median lowest reported platelet count was 46 × 109 /L [27.2, 73.5]. Intraoperatively, 61% (20/33) of patients were given unfractionated heparin (UFH), while 39% (13/33) were given alternative anticoagulants. The alternative agent subgroup required more antifibrinolytics [54% (7/13) vs 10% (2/20), P = .02] and clotting factors [69.2% (9/13) vs 15.0% (3/20), P < .01]. Perioperative thrombosis occurred more [53.8% (7/13) vs 0% (0/20, P < .01) in alternate agent subgroup. More patients in the alternate agent subgroup required post-operative transfusions [54% (7/13) vs 0% (0/20), P < .01]. Thirty-day mortality of 15.2% (5/33) was comparable between the subgroups. CONCLUSION: Heparin use during OHT may be associated with less adverse effects compared to use of other anticoagulants with no difference in 30-day mortality.

Utilization and outcomes of extracorporeal CO2 removal (ECCO2 R): Systematic review and meta-analysis of arterio-venous and veno-venous ECCO2 R approaches.

INTRODUCTION: Extracorporeal carbon dioxide removal (ECCO2 R) provides respiratory support to patients suffering from hypercapnic respiratory failure by utilizing an extracorporeal shunt and gas exchange membrane to remove CO2 from either the venous (VV-ECCO2 R) or arterial (AV-ECCO2 R) system before return into the venous site. AV-ECCO2 R relies on the patient's native cardiac function to generate pressures needed to deliver blood through the extracorporeal circuit. VV-ECCO2 R utilizes a mechanical pump and can be used to treat patients with inadequate native cardiac function. We sought to evaluate the existing evidence comparing the subgroups of patients supported on VV and AV-ECCO2 R devices. METHODS: A literature search was performed to identify all relevant studies published between 2000 and 2019. Demographic information, medical indications, perioperative variables, and clinical outcomes were extracted for systematic review and meta-analysis. RESULTS: Twenty-five studies including 826 patients were reviewed. 60% of patients (497/826) were supported on VV-ECCO2 R. The most frequent indications were acute respiratory distress syndrome (ARDS) [69%, (95%CI: 53%-82%)] and chronic obstructive pulmonary disease (COPD) [49%, (95%CI: 37%-60%)]. ICU length of stay was significantly shorter in patients supported on VV-ECCO2 R compared to AV-ECCO2 R [15 (95%CI: 7-23) vs. 42 (95%CI: 17-67) days, p = 0.05]. In-hospital mortality was not significantly different [27% (95%CI: 18%-38%) vs. 36% (95%CI: 24%-51%), p = 0.26]. CONCLUSION: Both VV and AV-ECCO2 R provided clinically meaningful CO2 removal with comparable mortality.

Incorporation of Green Capping Agents to Reduce Silver-Mediated Dentine Staining.

Silver diammine fluoride (SDF) is known as a noninvasive, cost-effective, safe, and simple method of dental caries treatment. However, staining and discoloration seem inseparable with SDF and continue as a cosmetic concern. Research is ongoing to overcome these issues, for example, by using glutathione (G) or potassium iodide among others. Therefore, the study aimed to investigate the effects of incorporating different concentrations of capping agents on SDF chemistry and SDF-mediated tooth staining at different time points. Tannic acid (TA), gallic acid (GA), carboxymethyl chitosan (CM), and G at different concentrations (5, 10, and 15% w/v) were incorporated in 30% SDF. FTIR and UV-Vis spectroscopies of the prepared solutions was performed to evaluate chemical changes. Time-dependent color changes (ΔE) in bovine dentine specimens (6 × 6 × 1 ± 0.25 mm3) were measured spectrophotometrically at application/washup, 1 and 3 h, after 1, 2, 4, 7, and 14 days. Results showed suppression of FTIR peaks at 3,358 cm-1 and 1,215 cm-1 in capping agent-modified SDF indicative of a successful capping effect of the silver ions, which was corroborated by UV-Vis blueshift of ∼∆32 nm. The capping effect on SDF increased proportionally with the concentrations of TA, GA, CM, and G used. A more pronounced tooth staining reduction however was shown more in TA- and G- rather than in GA- and CM-modified SDF. At day 14, SDF showed the highest mean ΔE(50.14 ± 2.14), while 15% TA showed the lowest ΔE(30.14 ± 0.81). In conclusion, capping agent incorporation significantly reduced SDF-mediated tooth staining. This reduction in staining is more dependent on the respective capping agent functional groups than concentrations per se. The potential of capping agents to minimize tooth staining of SDF was TA>G>CM>GA.

Frequency of underweight and stunting among children entering school in a small urban locality and their association with academic performance.

OBJECTIVE: To determine the frequency of underweight and stunting among the children entering first year of school and to assess its associated factors. METHODS: This descriptive, analytical study was conducted at 5 schools of Rabwah, Pakistan, from August to September 2015, and comprised all students who got admission in the selected schools during the study period. Name, father's name, gender, weight, height, status of height, and weight on Z-score charts, and marks obtained in the test were recorded. SPSS 20 was used for statistical analysis. RESULTS: Of the 478 participants, 212(44.4%) were boys and 266(55.6%) were girls. The overall mean age was 66.6±5.966 months (range: 41-129 months). Overall, 53(11.1%) were underweight, 22(4.6%) were severely underweight, 55(11.5%) had stunting and 12(2.5%) had severe stunting. Median marks (Interquartile Range [IQR]) in admission test for obese, overweight, normal, underweight and severely underweight children were 76.3%(37.2-84.7), 65.9%, 66.7%(56.4-72.3), 64.6%(47-71), and 67%(55.3-78), respectively. Median marks (IQR) in admission test for tall, normal height, stunted and severe stunted children were 24.1%, 67%(57.3-73), 57%(31.1-67.8), and 62.6%(49.7-68.3), respectively. Children with stunting scored significantly fewer marks compared to children of normal height (p<0.05). CONCLUSIONS: Stunting and underweight were common problems among children starting school. Stunting was found to be associated with lower marks in admission test.

Sided Stimulation of Endothelial Cells Modulates Neutrophil Trafficking in an In Vitro Sepsis Model.

While the role of dysregulated polymorphonuclear leukocyte (PMN) transmigration in septic mediated tissue damage is well documented, strategies to mitigate aberrant transmigration across endothelium have yet to yield viable therapeutics. Recently, microphysiological systems (MPS) have emerged as novel in vitro mimetics that facilitate the development of human models of disease. With this advancement, aspects of endothelial physiology that are difficult to assess with other models can be directly probed. In this study, the role of endothelial cell (EC) apicobasal polarity on leukocyte trafficking response is evaluated with the µSiM-MVM (microphysiological system enabled by a silicon membrane - microvascular mimetic). Here, ECs are stimulated either apically or basally with a cytokine cocktail to model a septic-like challenge before introducing healthy donor PMNs into the device. Basally oriented stimulation generated a stronger PMN transmigratory response versus apical stimulation. Importantly, healthy PMNs are unable to migrate towards a bacterial peptide chemoattractant when ECs are apically stimulated, which mimics the attenuated PMN chemotaxis seen in sepsis. Escalating the apical inflammatory stimulus by a factor of five is necessary to elicit high PMN transmigration levels across endothelium. These results demonstrate that EC apicobasal polarity modulates PMN transmigratory behavior and provides insight into the mechanisms underlying sepsis.

Microaxial mechanical circulatory support after orthotopic heart transplantation.

AIM: Use of microaxial mechanical circulatory support (MCS) has been reported for severe graft rejection or dysfunction after heart transplantation (HTx). We aimed to assess utilization patterns of microaxial MCS after HTx in adolescents (ages 18 and younger) and adults (ages 19 and older). METHODS: Electronic search was performed to identify all relevant studies on post-HTx use of microaxial support in adults and adolescents. A total of 18 studies were selected and patient-level data were extracted for statistical analysis. RESULTS: All patients (n=23), including adults (n=15) and adolescents (n=8), underwent Impella (Abiomed, Danvers, MA) microaxial MCS after HTx. Median age was 36 [IQR 18-56] years (Adults, 52 [37-59]; adolescents, 16 [15-17]). Primary right ventricular graft dysfunction was an indication exclusively seen in the adults 40% (6/15), while acute graft rejection was present in 46.7% (7/15) of adults. Median time after transplant was 9 [0-32] months (Adults, 4 [0-32]; adolescents, 11 [4.5, 45]). Duration of Impella support was comparable between adults and adolescents (5 [2.5-8] vs 6 [5-8] days, p = 0.38). Overall improvement was observed both in median LV ejection fraction (23.5% [11.3-28] to 42% [37.8-47.3], p < 0.01) and cardiac index (1.8 [1.2-2.6] to 3 [2.5-3.1], p < 0.01). Retransplantation was required in four adolescents (50%, 4/8). Survival to discharge was achieved by 60.0% (9/15) of adults and 87.5% (7/8) of adolescents respectively (p = 0.37). CONCLUSION: Indications for microaxial MCS appear to vary between adult and adolescent patients. Overall improvement in LVEF and cardiac index was observed, however, with suboptimal survival to discharge.

Outcomes of Valve-in-Valve Transcatheter Aortic Valve Replacement.

Structural valve degeneration is increasingly seen given the higher rates of bioprosthetic heart valve use for surgical and transcatheter aortic valve replacement (TAVR). Valve-in-valve TAVR (VIV-TAVR) is an attractive alternate for patients who are otherwise at high risk for reoperative surgery. We compared patients who underwent VIV-TAVR and native valve TAVR through a retrospective analysis of our institutional transcatheter valve therapy (TVT) database from 2013 to 2022. Patients who underwent either a native valve TAVR or VIV-TAVR were included. VIV-TAVR was defined as TAVR in patients who underwent a previous surgical aortic valve replacement. Kaplan-Meier survival analysis was used to obtain survival estimates. A Cox proportional hazards regression model was used for the multivariable analysis of mortality. A total of 3,532 patients underwent TAVR, of whom 198 (5.6%) underwent VIV-TAVR. Patients in the VIV-TAVR cohort were younger than patients who underwent native valve TAVR (79.5 vs 84 years, p <0.001), with comparable number of women and a higher Society of Thoracic Surgeons risk score (6.28 vs 4.46, p <0.001). The VIV-TAVR cohort had a higher incidence of major vascular complications (2.5% vs 0.8%, p = 0.008) but lower incidence of permanent pacemaker placement (2.5% vs 8.1%, p = 0.004). The incidence of stroke was comparable between the groups (VIV-TAVR 2.5% vs native TAVR 2.4%, p = 0.911). The 30-day readmission rates (VIV-TAVR 7.1% vs native TAVR 9%, p = 0.348), as well as in-hospital (VIV-TAVR 2% vs native TAVR 1.4%, p = 0.46), and overall (VIV-TAVR 26.3% vs native TAVR 30.8%, p = 0.18) mortality at a follow-up of 1.8 years (0.83 to 3.5) were comparable between the groups. The survival estimates were also comparable between the groups (log-rank p = 0.27). On multivariable Cox regression analysis, VIV-TAVR was associated with decreased hazards of death (hazard ratio 0.68 [0.5 to 0.9], p = 0.02). In conclusion, VIV-TAVR is a feasible and safe strategy for high-risk patients with bioprosthetic valve failure. There may be potentially higher short-term morbidity with VIV-TAVR, with no overt impact on survival.

Acute Aortic Dissection After Transcatheter Aortic Valve Replacement.

Acute aortic dissection (AAD) is a rare and potentially fatal complication associated with transcatheter aortic valve replacement (TAVR). Owing to the paucity of existing institutional data, we sought to assess the incidence of postimplant AAD in patients who underwent TAVR at a single institution. All patients who underwent TAVR from 2013 to 2022 were retrospectively reviewed to identify those who possessed clinical or radiologic evidence of AAD after TAVR. Follow-up and survival data were retrieved for all included patients. A total of 4,317 patients underwent TAVR, of whom 9 (0.2%) sustained an AAD. These patients had a mean age of 80 years (range 53 to 92), mean Society of Thoracic Surgeons 30-day mortality risk of 5.7% (2.4% to 16.7%), and mean effective aortic valve area of 0.8 cm2 (0.4 to 1.5 cm2). Preoperative maximum aortic diameter was 3.9 cm (2.6 to 4 cm). Of these 9 patients, 6 (67%) showed evidence of Stanford type A dissection, whereas 3 (33%) were diagnosed with Stanford type B dissection. The most common causes of dissection were posterior annular rupture by the transcatheter valve (THV) (44%) and THV embolization or "pop-out" into the ascending aorta (22%). A total of 6 patients (66.7%), comprising 5 type A (55.6%) and 1 type B (11.1%) aortic dissections, died within 30 days of AAD. The median time to follow-up in those surviving TAVR with intraoperative AAD was 1,042 days (range: 648 to 2,666). Surviving patients were managed through thoracic endovascular aortic repair and medical management. In conclusion, in this highly selected cohort of patients, our experience indicates that AAD after TAVR is a rare but often lethal intraprocedural sequela of THV implantation, especially in cases of type A aortic dissection.