Mitral valve surgery in octogenarians: long-term and hemodynamic results.

BACKGROUND: Octogenarians are often denied mitral valve (MV) surgery secondary to concerns over increased perioperative morbidity and mortality. The objective of this study was to examine the outcomes of octogenarians undergoing mitral valve repair (MVr) and replacement (MVR). METHODS: The outcomes of 139 patients between the ages of 80-90 who underwent MVR/MVr between 2004-2018 at the Mazankowski Alberta Heart Institute (Edmonton, AB, Canada) were retrospectively analyzed. Follow-up was extended to a maximum of 15.8 years. RESULTS: Following MVR, all-cause mortality at 30 days, 1 year, 5 years, 10 years, and the longest follow-up was 7%, 14%, 36.3%, 61.8%, and 67.7%, respectively. Post-MVr, all-cause mortality at the same time points was 1.9%, 7.6%, 22.5%, 55.5%, and 100%, respectively. During the Hospitalization Index, rates of new-onset atrial fibrillation, sepsis, acute kidney injury, superficial sternal wound infection, deep sternal wound infection, mediastinal bleeding, and permanent pacemaker insertion ranged from 22.1-34.0%, 3.8-11.0%, 7.6-22.0%, 1.9-2.4%, 0-1.2%, 0%, and 0-6.1%, respectively. Rates of overall rehospitalization, as well as readmission for heart failure, stroke, myocardial infarction, and MV reoperation ranged from 71.0-85.5%, 52.2-63.3%, 10.9-22.8%, 1.9-6.0%, and 0% during the follow-up period. There were significant reductions in peak MV gradient (P=0.042) and left ventricular internal diameter in diastole (LVIDd; P=0.008) post-MVR, as well as LVIDd (P<0.001) and Left Atrial (LA) Volume Index (P=0.019) post-MVr. CONCLUSIONS: Octogenarians exhibit positive left atrial and left ventricular remodeling following MVR. Perioperative morbidity is low, late survival is reasonable, and long-term morbidity is considerable. Overall, these results add to the growing literature that MV surgery is relatively safe and effective in octogenarians.

Tissue versus mechanical mitral valve replacement in patients aged 50-70: a propensity-matched analysis.

OBJECTIVES: There remains debate over the optimal mitral valve replacement (MVR) option for patients aged 50-70 years. The objective of this study was to retrospectively compare the long-term outcomes of mechanical and bioprosthetic MVR in this patient population. METHODS: Data from patients undergoing MVR between 2004 and 2018 were retrospectively reviewed. The primary outcome was all-cause mortality. Secondary outcomes included perioperative and late morbidity. RESULTS: Two hundred and eight-six propensity-matched patients (n = 143 mechanical; n = 143 bioprosthetic) aged 50-70 years were included in the final analysis. Maximum follow-up was 15.8 years. There was no significant difference in all-cause mortality between the groups at 30 days, 1 year, 5 years, 10 years, and at the longest follow-up. Patients who underwent mechanical MVR experienced significantly lower rates of postoperative atrial fibrillation (P = 0.001). There were no significant differences in rates of sepsis, acute kidney injury, superficial and deep sternal wound infection, mediastinal bleeding, and permanent pacemaker implantation. At the longest follow-up, there were no differences in myocardial infarction, stroke, heart failure or overall rehospitalization. At the same time point, there was an increased rate of MVR in patients receiving a bioprosthetic valve (P = 0.015). CONCLUSIONS: Survival following mechanical and bioprosthetic MVR in patients 50-70 years of age is similar to up to 15 years of follow-up. Bioprosthetic MVR is associated with an increased risk of repeat MVR. Mechanical MVR is not associated with an increased risk of stroke. Valve selection in this patient population requires diligent consideration of structural valve deterioration and subsequent reoperation risk as well as bleeding and thromboembolic risk.

Systematic review and meta-analysis of the impact of sex on outcomes after aortic valve replacement.

AIMS: In recent years, extensive literature has been produced demonstrating inferior outcomes for women when compared with men undergoing heart valve interventions. Herein, we seek to analyze the literature comparing outcomes between men and women undergoing surgical aortic valve replacement (SAVR). METHODS: A systematic literature search of PubMed, MEDLINE, and Embase was conducted for articles comparing differences in outcomes between adult men and women undergoing SAVR. One thousand nine hundred and ninety titles were screened, of which 75 full texts were reviewed, and a total of 19 manuscripts met the inclusion criteria and were included in this review. RESULTS: Pooled estimates of mortality demonstrated that women tended to have lower rates of survival within the first 30 days post-SAVR, although mid-term and long-term mortality did not differ significantly up to 10 years postoperatively. Pooled estimates of postoperative data indicated no difference in the rates of stroke and postoperative bleeding. Rates of aortic valve reoperation and acute kidney injury favored women. CONCLUSION: Despite the inferior outcomes for women post-SAVR that have been reported in recent years, the results of this meta-analysis demonstrate comparable results between the sexes with comparable mid- to long-term mortality in data pooled from the literature. Although mortality favored men in the short term, rates of aortic valve reoperation and acute kidney injury favored women. Future investigation into this field should focus on identifying discrepancies in diagnosis and initial surgical management in order to address any potential factors contributing to discrepant short-term outcomes. GRAPHICAL ABSTRACT: http://links.lww.com/JCM/A651.

Minimally Invasive Approaches to Mitral Valve Surgery: Where Are We Now? A Narrative Review.

Minimally invasive mitral valve surgery (MiMVS) has been increasing in prevalence. This review focuses on the approaches, clinical outcomes, and patient selection for MiMVS. There are 4 minimally invasive approaches to the mitral valve: right mini-thoracotomy (including video-assisted and fully endoscopic), robotic mitral surgery, and transapical beating heart off-pump neochordal repair. Advantages over conventional surgery include less blood loss and transfusion, improved postoperative mobility, shorter length of stay, less postoperative atrial fibrillation, fewer surgical site infections, and improved cosmesis. This range of minimally invasive techniques will continue to evolve, providing options that are tailored for different patient populations.

Relation of body mass index to long-term survival and cardiac remodelling for patients undergoing mitral valve replacement surgery.

BACKGROUND AND AIMS: Studies have demonstrated that obesity is paradoxically associated with reduced mortality following cardiac surgery. However, these studies have treated various types of cardiac surgery as a single entity. With mitral valve (MV) surgeries being the fastest-growing cardiac surgical interventions in North America, the purpose of this study was to identify the impact of body mass index (BMI) on long-term survival and cardiac remodelling of patients undergoing MV replacement (MVR). METHODS AND RESULTS: In this retrospective, single-center study, 1071 adult patients who underwent an MVR between 2004 and 2018 were stratified into five BMI groups (<20, 20-24.9, 25-29.9, 30-34.9, >35). Cox proportional hazard regression models were used to determine the association between BMI and all-cause mortality. Patients who were underweight had significantly higher all-cause mortality rates at the longest follow-up (median 8.2 years) than patients with normal weight (p = 0.01). Patients who were in the obese group had significantly higher readmission rates due to myocardial infarction (MI) at the longest follow-up (p = 0.017). Subgroup analysis revealed a significant increase in long-term all-cause mortality for female patients who were underweight. Significant changes in left atrial size, mitral valve peak and mean gradients were seen in all BMI groups. CONCLUSIONS: For patients undergoing mitral valve replacement, BMI is unrelated to operative outcomes except for patients who are underweight.

Teaching heart valve surgery techniques using simulators: a systematic review.

The apprentice model has traditionally been the primary method of teaching cardiac surgery trainees. Limitations of this model include insufficient time to learn all necessary skills, minimal exposure to rare cases and to complex repair techniques, small number of patients in small centres, high cost and absence of objective measures of feedback. In recent years, simulation-based training (SBT) has been used in order to address the gaps left by the apprentice model. We performed a systematic review of PubMed and Embase for articles investigating the use of SBT in teaching surgical valve techniques published in 2022 or earlier in order to summarize the current literature regarding the use of SBT for trainees learning surgical valve repair and replacement techniques. We compiled data on the impact of SBT on time to completion of tasks, proportion of trainees who committed technical errors, skills scores and theoretical knowledge. Studies in which outcomes were evaluated showed significant improvement in these measures after participation in SBT. Simulation-based training has been shown to improve the surgical skills of trainees in a rela-tively short period. As hands-on experience in the field of cardiac surgery is invaluable and often difficult to reproduce effectively, it is likely that a combination of hands-on training and SBT will be adopted moving forward to provide optimal exposure for surgical trainees.

Effect of glucagon-like peptide-1 receptor agonists administration during coronary artery bypass grafting: a systematic review and meta-analysis of randomized control trials.

Aim: To determine if glucagon-like peptide-1 receptor agonists (GLP-1 RAs) can benefit patients receiving coronary artery bypass graft (CABG), GLP-1 RAs administration alongside standard insulin was compared with perioperative insulin alone. Materials & methods: All articles from Pubmed and Scopus databases that compared GLP-1 RA administration to insulin alone during CABG were included for meta-analysis. Short-term postoperative outcomes were analyzed between groups. Results: Average postoperative blood glucose levels significantly favored GLP-1 RA with a mean difference of -0.72 (p < 0.001). No other variables were significantly different between GLP-1 RA and insulin alone. Conclusion: GLP-1 RA is a safe option for perioperative care of CABG patients that can potentially improve postoperative outcomes of CABG patients by improving glycemic control and reducing hyperglycemic episodes.

What is this article about? Coronary artery bypass graft (CABG) is a common surgery for patients who have blocked blood vessels in their heart preventing their heart from functioning properly. Compared with other treatment options, CABG has better long-term outcomes and chances of survival, especially for patients with diabetes. Some medications that lower blood sugar levels in patients with diabetes, are also well known to improve heart health in this population. Because of these benefits, the specific medication called GLP-1 RA, has been proposed as an option to improve outcomes of people receiving CABG surgery. What were the results? By taking a systematic approach, 1375 articles were screened to find seven trials that tested the comparison of GLP-1 RA versus a control of just insulin in CABG patients. Analyzing this data, CABG patients receiving GLP-1 RA had significantly lower blood sugar levels compared with patients getting the control. The GLP-1 RA group also, on average, had similar or lower levels of heart rate arrhythmias, events of critically low blood sugar and the need of serious interventions compared with the control group. What do the results of the study mean? These results demonstrate that GLP-1 RA have similar or improved outcomes compared with standard therapy alone, suggesting it as a safe option for CABG patients. By lowering blood sugar levels, GLP-1 RA could also decrease complication rates and improve patient management compared with standard therapy alone, since high blood sugar levels are correlated with increased complications and worse postoperation outcomes.

The influence of renal disease on outcomes and cardiac remodeling following surgical mitral valve replacement.

OBJECTIVES: Chronic kidney disease (CKD) is increasingly prevalent in patients undergoing mitral valve replacement (MVR). While CKD is known to result in suboptimal outcomes for patients with mitral valve disease, there is limited literature evaluating the long-term outcomes and cardiac remodeling of patients with CKD undergoing MVR. We present the first analysis coupling long-term outcomes of combined morbidity, mortality, and cardiac remodeling post-MVR in patients with CKD. METHODS: Patients with varying degrees of CKD undergoing MVR from 2004 to 2018 were compared. Patients were grouped by estimated glomerular filtration rate (eGFR) > 90 mL/min/1.73m2 (n = 109), 60-89 mL/min/1.73m2 (450), 30-59 mL/min/1.73m2 (449), < 30 mL/min/1.73m2 (60). The primary outcome was mortality. Secondary outcomes included measures of postoperative morbidity and cardiac remodeling. RESULTS: One-year mortality was significantly increased in patients with eGFR < 30 (p = 0.023). Mortality at 7 years was significantly increased in patients with eGFR < 30 mL/min/1.73m2 (p < 0.001). Multivariable regression analysis of 7-year all-cause mortality indicated an eGFR of 15 mL/min/1.73m2 (HR 4.03, 95% CI 2.54-6.40) and 30 mL/min/1.73m2 (HR 2.17 95% CI 1.55-3.05) were predictive of increased mortality. Reduced eGFR predicted the development of postoperative sepsis (p = 0.002), but not other morbidities. Positive cardiac remodeling of the left ventricle, left atrium, and valve gradients were identified postoperatively for patients with eGFR > 30 mL/min/1.73m2 while patients with eGFR < 30 mL/min/1.73m2 did not experience the same changes. CONCLUSIONS: CKD is predictive of inferior clinical and echocardiographic outcomes in patients undergoing MVR and consequently requires careful preoperative consideration and planning. Further investigation into optimizing the postoperative outcomes of this patient population is necessary.

Quantifying the immune response to a tissue-engineered porcine extracellular matrix.

Aim: Structural valvular deterioration of xenogenic heart valve replacements is thought to be due to a chronic immune response. We sought to engineer porcine extracellular matrix that elicits minimal inflammatory immune response. Materials & methods: Whole blood, bone marrow and pericardium were collected from patients undergoing elective cardiac surgery. Porcine extracellular matrix was decellularized, reseeded with homologous mesenchymal stem cells and exposed to whole blood. Results: DAPI stain confirmed the absence of cells after decellularization, and presence of mesenchymal stem cells after recellularization. There was a significant reduction in IL-1ß and TNF-α production in the recellularized matrix. Conclusion: Recellularization of porcine matrix is successful at attenuating the xenogenic immune response and may provide a suitable scaffold to address the current limitations of prosthetic heart valve replacements.

Deterioration of tissue heart valve replacements is thought to be due to a chronic immune response. We sought to remove cells from a pig derived tissue and replace those cells with human stem cells to create a scaffold that results in a reduced immune response. Whole blood, bone marrow and pericardium were collected from patients undergoing elective cardiac surgery. The pig derived tissue had the cells removed, were replaced with human stem cells and exposed to whole blood. Tissue stain confirmed the absence of cells after removal, and presence of stem cells after replacement of cells. There was a significant reduction in markers of immune response in the recellularized tissue. Removal of cells from pig derived tissue and replacement with human stem cells is successful at reducing the immune response to animal tissue and may provide a suitable scaffold to address the current limitations of heart valve replacement options.

Does sex impact outcomes after mitral valve surgery? A systematic review and meta-analysis.

BACKGROUND AND OBJECTIVE: The published literature investigating the impact of sex on outcomes after mitral valve (MV) surgery has demonstrated inferior outcomes for females over males. However, the true relationship between sex and outcomes after MV surgery continues to be poorly understood. MATERIALS: PubMed, Medline, and Embase were systematically searched for articles published from 1 January 2005 to 1 August 2021. This systematic review included retrospective and prospective studies investigating the relationship between sex and outcomes after MV surgery. In all, 2068 articles were initially screened and 12 studies were included in this review. RESULTS: Few studies were adequately powered or structured to investigate this topic. Few studies propensity matched patients or isolated for surgical approach. In individual studies, females experienced increased rates of short-term and long-term mortality and increased 1-year mortality in the pooled data. Males experienced increased rates of required pacemaker insertion. The remaining rates of morbidity and mortality did not differ significantly between males and females. CONCLUSIONS: This review identified increased rates of 1-year mortality in the pooled data for females, while males had increased rates of pacemaker insertion. Despite this, the absence of propensity matching and isolating for surgical approach has introduced confounding variables that impair the ability of the included studies to interpret the results found in the current literature. Studies isolating for surgical approach, propensity matching patients, and examining outcomes with long-term follow-up are required to elucidate the true nature of this relationship.

Recellularized bovine pericardium with autologous mesenchymal stem cells reduces immune activation.

INTRODUCTION: Current bioprosthetic heart valve replacement options are limited by structural valvular deterioration (SVD) due to an immune response to the xenogenic scaffold. Autologous mesenchymal stem cell (MSC) recellularization is a method of concealing xenogenic scaffolds, preventing recipient immune recognition of xenogenic tissue heart valves, and potentially leading to reduction in SVD incidence. The purpose of this study is to examine the effects of autologous MSC recellularized tissue on the immune response of human whole blood to bovine pericardium (BP). We hypothesized that autologous MSC recellularization of BP will result in reduced pro-inflammatory cytokine production equivalent to autologous human pericardium. METHODS: Bone marrow, human pericardium, and whole blood were collected from adult patients undergoing elective cardiac surgery. Decellularized BP underwent recellularization with autologous MSCs, followed by co-incubation with autologous whole blood. Immunohistochemical, microscopic, and quantitative immune analysis approaches were used. RESULTS: We demonstrated that native BP, exposed to human whole blood, results in significant TNF-α and IL1ß production. When decellularized BP is recellularized with autologous MSCs and exposed to whole blood, there is a significant reduction in TNF-α and IL1ß production. Importantly, recellularized BP exposed to whole blood had similar production of TNF-α and IL1ß when compared to autologous human pericardium exposed to human whole blood. CONCLUSION: Our results suggest that preventing initial immune activation with autologous MSC recellularization may be an effective approach to decrease the recipient immune response, preventing recipient immune recognition of xenogeneic tissue engineered heart valves, and potentially leading to reduction in SVD incidence.

Sex differences in acute type A aortic dissection: a systematic review and meta-analysis.

INTRODUCTION: The objective of this study is to provide a comprehensive comparison of outcomes following acute type A aortic dissection (ATAAD) repair in males and females. EVIDENCE ACQUISITION: PubMed, Medline, and Web of Science were systematically searched by two authors for studies published from January 1st, 2000, to May 10th, 2021. Overall, 2405 articles were screened, and 16 were included in this review. Meta-analysis of the compiled data was performed. EVIDENCE SYNTHESIS: Pooled estimates indicated no difference in operative (odds ratio (OR) 1.00, 95% confidence interval (CI) 0.59-1.67, P=0.99, I2=52%), in-hospital (OR 0.78, 95% CI 0.56-1.08; P=0.13, I2=57%), and 30-day mortality (OR 1.09, 95% CI 0.83-1.43, P=0.52, I2=45%) between the sexes. However, males had significantly reduced 5-year mortality rates (OR 0.71, 95% CI 0.51-1.00, P=0.05, I2=45%). There was no difference between sexes in rates of postoperative stroke (OR 1.07, 95% CI 0.86-1.33, P=0.54, I2=0%), atrial fibrillation (OR 0.99, 95% CI 0.82-1.19, P=0.92, I2=0%), as well as mesenteric or limb ischemia (OR 0.73, 95% CI 0.22-2.43, P=0.61, I2=77%; OR 0.83, 95% CI 0.30-2.30, P=0.72, I2=76%, respectively). Males did experience significantly increased rates of acute renal failure and reoperation (OR 1.35, 95% CI 1.16-1.56, P=0.0001, I2=29%; OR 1.40, 95% CI 1.09-1.81, P=0.010, I2=42%). CONCLUSIONS: Composite analysis indicates that early mortality does not differ between the sexes; however, late outcomes favor males. Differences in preoperative presentation and subsequent procedure selection between the sexes likely contribute to the disparity in late outcomes. Decision-making for surgical treatment of ATAAD should account for sex-specific risk factors.

Mortality and morbidity of surgical and transcatheter mitral valve repair in octogenarians: A systematic review.

BACKGROUND: Valvular heart disease (VHD) is a prominent problem in healthcare today with mitral regurgitation (MR) being the leading cause of VHD in the elderly population. While mitral valve repair (MVr) surgery is one of the only options for the end-stage disease, octogenarians are often denied MVr due to concerns with operative mortality and postoperative morbidity. To provide information on this underrepresented group of surgical patients, a systematic approach was taken to review the mortality and morbidity rates of octogenarians who received MVr. METHODS: Pubmed and Medline were searched for articles containing outcomes of octogenarians receiving surgical mitral valve repair (SMVr) or transcatheter mitral valve repair (TMVr) published after 2000. Ten articles met the inclusion criteria for a total of 7968 patients included in the analysis using Microsoft Excel, Version 2105. RESULTS: Short-term mortality rates for SMVr and TMVr were 2.6% and 1.4% for in-hospital, and 7.8% and 3.3% for 30 days, respectively. The average incidence of stroke, acute kidney injury, infection, and major bleeding for SMVr were 3.2%, 11.2%, 7.7%, and 24%, respectively, and 0.3%, 6.7%, 2.7%, and 7.9% for TMVr, respectively. CONCLUSION: Octogenarians receiving SMVr or TMVr experienced similar rates of short-term mortality and morbidity as younger populations, and when considering life expectancy, midterm mortality was also similar. With these results, denying octogenarians MVr operations based on age alone should be reconsidered. Depending on risk factors and comorbidities, either SMVr or TMVr is a viable and relatively safe option for octogenarians with severe MR.

A systematic review and meta-analysis of coronary artery disease and revascularization in lung transplant patients.

Coronary artery disease (CAD) is common in candidates for lung transplantation (LTx) and has historically been considered a relative contraindication to transplantation. We look to review the outcomes of LTx in patients with CAD and determine the optimum revascularization strategy in LTx candidates. PubMed, Medline and Web of Science were systematically searched by three authors for articles comparing the outcomes of LTx in patients with CAD and receiving coronary revascularization. In total 1668 articles were screened and 12 were included in this review.Preexisting CAD in LTx recipients was not associated with significantly increased postoperative morbidity or mortality. The pooled estimates of mortality rate at 1, 3 and 5 years indicated significantly inferior survival in LTx recipients with a prior history of coronary artery bypass grafting (CABG) [odds ratio (OR), 1.84; 95% confidence interval (CI), 1.53-2.22; P < 0.00001; I2 = 0%; OR, 1.52; 95% CI, 1.21-1.91; P = 0.0003; I2 = 0%; OR, 1.62; 95% CI, 1.13-2.33; P = 0.008; I2 = 71%, respectively). However, contemporary literature suggests that survival rates in LTx recipients with CAD that received revascularization either by percutaneous coronary intervention (PCI), previous or concomitant CABG, are similar to patients who did not receive revascularization. Trends in postoperative morbidity favored CABG in the rates of myocardial infarction and repeat revascularization, whereas rates of stroke favored PCI. The composite results of this study support the consideration of patients with CAD or previous coronary revascularization for LTx. Prospective, randomized controlled trials with consistent patient populations and outcomes reporting are required to fully elucidate the optimum revascularization strategy in LTx candidates.

Sex-Related Differences in Transcatheter Mitral Valve Repair: A Systematic Review and Meta-Analysis.

OBJECTIVE: Inequalities in postoperative outcomes between males and females are well described with females often experiencing inferior outcomes after heart valve surgery. The recent literature has demonstrated equivalent or improved outcomes for females after transcatheter aortic valve replacement. Transcatheter mitral valve repair (TMVr) and replacement (TMVR) is a relatively newer field with significantly less literature comparing sex differences. This systematic review and meta-analysis looks to provide a comprehensive summary of the published literature comparing outcomes between males and females undergoing transcatheter MV interventions. METHODS: PubMed, MEDLINE, and Scopus were systematically searched for all studies comparing outcomes between males and females undergoing TMVr and TMVR. A total of 2,178 English manuscript titles and abstracts were reviewed. Articles were excluded if data were not provided regarding sex differences, transcatheter MV intervention, full-length text was not accessible, or if insufficient data was provided. A total of 2,170 articles were excluded, and 8 articles were included in this study. RESULTS: Pooled estimates of outcomes demonstrated rates of acute kidney injury (OR 1.28 [95% CI, 1.14-1.44; p < 0.0001]) favored females, while rates of major bleeding favored males (OR 0.85 [95% CI 0.76-0.96; p = 0.01]). Rates of mortality, postoperative MI, and stroke did not differ significantly. CONCLUSION: A trend has emerged in heart valve interventions with males tending to have improved outcomes after surgical intervention and females experiencing equivalent or improved outcomes after transcatheter interventions. This meta-analysis identified increased rates of acute kidney injury for males, increased rates of major bleeding for females, and otherwise comparable morbidity and mortality in males and females undergoing TMVr.

Coronary Revascularization for Patients with Diabetes Mellitus: A Contemporary Systematic Review and Meta-Analysis.

OBJECTIVE: This systematic review and meta-analysis aims to review the contemporary literature comparing CABG and PCI in diabetic patients providing an up-to-date perspective on the differences between the interventions. BACKGROUND: Diabetes is common and diabetic patients are at a 2-to-4-fold increased risk of developing coronary artery disease. Approximately 75% of diabetic patients die of cardiovascular disease. Previous literature has identified CABG as superior to PCI for revascularization in diabetic patients with complex coronary artery diseas. METHODS: PubMed and Medline were systematically searched for articles published from January 1, 2015 to April 15, 2021. This systematic review included all retrospective, prospective, and randomized trial studies comparing CABG and PCI in diabetic patients. 1552 abstracts were reviewed and 25 studies were included in this review. The data was analyzed using the RevMan 5.4 software. RESULTS: Diabetic patients undergoing CABG experienced significantly reduced rates of 5-year mortality, major adverse cardiovascular and cerebrovascular events, myocardial infarction, and required repeat revascularization. Patients who underwent PCI experienced improved rates of stroke that trended toward significance. CONCLUSIONS: Previous literature regarding coronary revascularization in diabetic patients has consistently demonstrated superior outcomes for patients undergoing CABG over PCI. The development of 1st and 2nd generation DES have narrowed the gap between CABG and PCI, but CABG continues to be superior. Continued investigation with large randomized trials and retrospective studies including long term follow-up comparing CABG and 2nd generation DES is necessary to confirm the optimal intervention for diabetic patients.

Heart valve surgery and the obesity paradox: A systematic review.

Obesity has been associated with increased incidence of comorbidities and shorter life expectancy, and it has generally been assumed that patients with obesity should have inferior outcomes after surgery. Previous literature has often demonstrated equivalent or even improved rates of mortality after cardiac surgery when compared to their lower-weight counterparts, coined the obesity paradox. Herein, we aim to review the literature investigating the impact of obesity on surgical valve interventions. PubMed and Embase were systematically searched for articles published from 1 January 2000 to 15 October 2021. A total of 1315 articles comparing differences in outcomes between patients of varying body mass index (BMI) undergoing valve interventions were reviewed and 25 were included in this study. Patients with higher BMI demonstrated equivalent or reduced rates of postoperative myocardial infarction, stroke, reoperation rates, acute kidney injury, dialysis and bleeding. Two studies identified increased rates of deep sternal wound infection in patients with higher BMI, although the majority of studies found no significant difference in deep sternal wound infection rates. The obesity paradox has described counterintuitive outcomes predominantly in coronary artery bypass grafting and transcatheter aortic valve replacement. Recent literature has identified similar trends in other heart valve interventions. While the obesity paradox has been well characterized, its causes are yet to be identified. Further study is essential in order to identify the causes of the obesity paradox so patients of all body sizes can receive optimal care.

Recellularization of xenograft heart valves reduces the xenoreactive immune response in an in vivo rat model.

OBJECTIVES: Our aim was to address the role of autologous mesenchymal stem cell recellularization of xenogenic valves on the activation of the xenoreactive immune response in an in vivo rat model. METHODS: Explanted aortic valve constructs from female Hartley guinea pigs were procured and decellularized, followed by recellularization with autologous Sprague-Dawley rat mesenchymal stem cells. Aortic valve xenografts were then implanted into the infrarenal aorta of recipient rats. Grafts were implanted as either autologous grafts, non-decellularized (NGP), decellularized and recellularized xenografts (RGP). Rats were euthanized after 7 and 21 days and exsanguinated and the grafts were explanted. RESULTS: The NGP grafts demonstrated significant burden of granulocytes (14.3 cells/HPF) and CD3+ T cells (3.9 cells/HPF) compared to the autologous grafts (2.1 granulocytes/HPF and 0.72 CD3+ T cells/HPF) after 7 days. A lower absolute number of infiltrating granulocytes (NGP vs autologous, 6.4 vs 2.4 cells/HPF) and CD3+ T cells (NGP vs autologous, 2.8 vs 0.8 cells/HPF) was seen after 21 days. Equivalent granulocyte cell infiltration in the RGP grafts (2.4 cells/HPF) compared to the autologous grafts (2.1 cells/HPF) after 7 and 21 days (2.8 vs 2.4 cells/HPF) was observed. Equivalent CD3+ T-cell infiltration in the RGP grafts (0.63 cells/HPF) compared to the autologous grafts (0.72 cells/HPF) after 7 and 21 days (0.7 vs 0.8 cells/HPF) was observed. Immunoglobulin production was significantly greater in the NGP grafts compared to the autologous grafts at 7 (123.3 vs 52.7 mg/mL) and 21 days (93.3 vs 71.6 mg/mL), with a similar decreasing trend in absolute production. Equivalent immunoglobulin production was observed in the RGP grafts compared to the autologous grafts at 7 (40.8 vs 52.7 mg/mL) and 21 days (29.5 vs 71.6 mg/mL). CONCLUSIONS: Autologous mesenchymal stem cell recellularization of xenogenic valves reduces the xenoreactive immune response in an in vivo rat model and may be an effective approach to decrease the progression of xenograft valve dysfunction.

Sternal Bone Marrow Harvesting and Culturing Techniques from Patients Undergoing Cardiac Surgery.

BACKGROUND: Mesenchymal stromal cells (MSCs) are the most prominent cell type used in clinical regenerative medicine and stem cell research. MSCs are commonly harvested from bone marrow that has been aspirated from patients' iliac crest. However, the ethical challenges of finding consenting patients and obtaining fresh autologous cells via invasive extraction methods remain to be barriers to MSC research. METHODS: Techniques of harvesting sternal bone marrow, isolating and culturing MSCs, MSC surface phenotyping, and MSC differentiation are described. Samples from 50 patients undergoing a sternotomy were collected, and the time taken to reach 80% confluency and cell count at the second splitting of MSC were measured. RESULTS: MSC isolated from the sternal bone marrow of patients undergoing cardiac surgery demonstrated successful MSC surface phenotyping and MSC differentiation. The mean cell count at the time of the second split was 1,628,025, and the mean time taken to reach the second split was 24.8 days. CONCLUSION: Herein, we describe the first reported technique of harvesting sternal bone marrow from patients already undergoing open-chest cardiac surgery to reduce the invasiveness of bone marrow harvesting, as well as the methods of isolating, culturing, and identifying MSCs for the clinical application of constructing autologous MSC-derived biomaterials.