Incidence, risk factors, and long-term outcomes associated with permanent pacemaker implantation after aortic root replacement.

OBJECTIVE: Permanent pacemaker implantation (PPI) after AVR is associated with long-term mortality. However, data regarding PPI after aortic root replacement (ARR) is lacking. Herein we describe the incidence, risk factors, and long-term outcomes of PPI after ARR. METHODS: Consecutive patients undergoing ARR from 2005-2020 were selected after excluding those with endocarditis, Type A dissection, or preoperative PPI. Patients requiring PPI after ARR were identified, along with the indication and timing. Independent factors associated with PPI after ARR were identified and long-term survival was assessed. RESULTS: The incidence of PPI was 3.8% (n=85) among 2240 patients undergoing ARR. PPI was performed a median of 7 days (IQR 5-12) after ARR most commonly for complete heart block (73%). Bicuspid aortic valve (OR 1.89, p=0.02), female gender (OR 1.74, p=0.04), preoperative heart block (OR 2.70, p=0.02), and prior AVR (OR 2.18, p=0.01) were independently associated with PPI while preoperative aortic insufficiency (OR 0.52, p=0.01) and VSRR procedure compared to bio-Bentall (OR 0.40, p=0.01) were protective. Patients requiring PPI after ARR were not at increased risk of operative or long-term mortality compared to patients not requiring PPI (p=0.26), however those undergoing PPI suffered from significantly longer hospital length of stay (13 vs 7 days, p<0.001). CONCLUSIONS: The incidence of PPI after ARR remains low, particularly after VSRR. Preoperative conduction disturbance, prior AVR, and bicuspid AV are all associated with increased risk of PPI. While PPI is associated with longer length of stay, it is not associated with early or late mortality.

Somatostatin receptors in fibrotic myocardium.

A patient with a neuroendocrine tumor and history of coronary artery disease underwent PET with 68Ga-DOTATATE PET tracer for tumor visualization. Analysis of the scan showed uptake of 68Ga-DOTATATE in the left ventricle corresponding to previous myocardial infarct. 68Ga-DOTATATE binds by somatostatin receptors (SSTR) and it has been proposed that it may be useful for the detection of cardiac inflammatory lesions. We aimed to test whether SSTR could be upregulated in cardiac fibrotic scar. We analyzed SSTR in cardiac samples from patients with end-stage ischemic cardiomyopathy (ICM, n = 8) and control hearts (n = 5). In mature ICM tissue, SSTR1 and SSTR2 expression was unchanged and SSTR5 expression was significantly decreased in ICM samples vs. control. Immunohistochemistry showed increased SSTR1 and SSTR2 in ICM. Areas with SSTR1 or SSTR2 staining were often adjacent to fibrotic areas. The majority of SSTR1 and SSTR2 staining localized in cardiomyocytes in fibrotic scar-rich areas where CD68 macrophage staining was not present. SSTR are occasionally upregulated in cardiac fibrotic areas. When using 68Ga-DOTATATE PET tracer to detect cardiac sarcoidosis or atherosclerotic plaque, the possibility of tracer uptake in fibrotic areas should be considered.

Co-activation of Mas and pGCA receptors suppresses Endothelin-1-induced endothelial dysfunction via nitric oxide/cGMP system.

BACKGROUND: The aortic endothelium is crucial in preserving vascular tone through endothelium-derived vasodilators and vasoconstrictors. Dysfunction in the endothelium is an early indicator of cardiovascular diseases. Our study explores the therapeutic potential of a dual-acting peptide (DAP) to co-activate Mas and pGCA receptors and restore the balance between vasodilators and vasoconstrictors on endothelial dysfunction in DOCA-salt-induced hypertensive rats. METHODS: DOCA-salt was administered to male wistar rats to induce hypertension, and various parameters, including blood pressure (BP), water intake and body weight were monitored. DAP, Ang1-7, BNP, and losartan were administered to hypertensive rats for three weeks. Histological analysis and isometric tension studies were carried out to assess endothelial function. In addition to this, we used primary aortic endothelial cells for detailed mechanistic investigations. RESULTS: DOCA-salt administration significantly elevated systolic, diastolic, mean arterial BP, and water intake whereas, downregulated the gene expression of Mas and pGCA receptors. However, DAP co-administration attenuated BP increase, upregulated the gene expression of Mas and pGCA receptors, normalized serum and urinary parameters, and effectively reduced fibrosis, inflammation, and vascular calcification. Notably, DAP outperformed the standard drug, Losartan. Our findings indicate that DAP restores aortic function by balancing the NO and ET1-induced pathways. CONCLUSION: Co-activating Mas and pGCA receptors with DAP mitigates vascular damage and enhances endothelial function, emphasizing its potential to maintain a delicate balance between vasodilatory NO and vasoconstrictor ET1 in endothelial dysfunction.

Mitral regurgitation mechanisms related to systolic anterior motion in hypertrophic cardiomyopathy.

Background: Systolic anterior motion (SAM) of the mitral valve can result in mitral regurgitation (MR) and adverse outcomes in patients with obstructive hypertrophic cardiomyopathy (HCM). However, the mechanism and characteristics of MR severity mediated by SAM are unresolved. This study aimed to elucidate the anatomic and hemodynamic associations of MR and the impact of septal myectomy on changes in MR severity in patients with HCM. Methods: We retrospectively reviewed patients who underwent septal myectomy with SAM and interpretable imaging between 2017-2022. Significant MR was defined as moderate or more MR. The mitral valve, papillary muscle, and left ventricular geometry were quantitatively evaluated via echocardiography and cardiac computed tomography. Results: Out of 34 patients, two groups were identified: those with preoperative significant MR (n=16) and those without significant MR (n=18). Patients with significant preoperative MR exhibited worse heart failure symptoms at baseline than those without. Following myectomy, these patients showed higher residual left ventricular outflow tract (LVOT) gradients at rest and with provocative measures than those without preoperative MR. Multivariate regression analysis revealed a significant association between the tenting area and MR severity. Additionally, the chordal cutting procedure alleviated the tenting area [2.1 (1.8-2.6) vs. 1.4 (1.2-1.6) cm2] compared to those without it. Conclusions: Our preliminary data suggested that chordal cutting with septal myectomy was associated with an improvement in the tenting area, contributing to MR severity. This procedure may serve as an effective therapy for patients with SAM and significant MR.

Mechanical Circulatory Support During Surgical Revascularization for Ischemic Cardiomyopathy.

BACKGROUND: This study aimed to describe the use of perioperative mechanical circulatory support (MCS) and its impact on outcomes in patients with ischemic cardiomyopathy who were undergoing surgical revascularization. METHODS: Patients with an ejection fraction <35% who underwent isolated coronary artery bypass grafting (CABG) from 2015 to 2021 were identified (N = 378). Patients were divided into no MCS, preoperative MCS, and postoperative MCS groups on the basis of timing of MCS initiation, which included intraaortic balloon pump, extracorporeal membrane oxygenation, or Impella device (Abiomed) use. The primary outcome of interest was operative mortality. RESULTS: The median Society of Thoracic Surgeons Predicted Risk of Mortality was 2.4%. Sixty-six percent (n = 246) of patients had a previous myocardial infarction, and 61.8% of these patients were within 21 days of CABG. Twenty-one patients (5.6%) presented in cardiogenic shock. The preoperative MCS cohort consisted of 31 patients (8.2%) who underwent CABG a median of 2 days after MCS initiation. Thirty (7.9%) patients required postoperative MCS. Independent risk factors for requiring postoperative MCS included the preoperative ejection fraction (odds ratio, 0.93; P = .01 and the presence of preoperative MCS (odds ratio, 3.06; P = .02). Overall, operative mortality was 3.4%, and 3-year survival was 87.0%. Operative mortality in patients who did and did not receive preoperative MCS was 7.7% and 2.9% (P = .12) with no difference in long-term survival (P = .80), whereas patients requiring postoperative MCS had significantly increased operative (16.7%) and late mortality (63%; P <.01). CONCLUSIONS: CABG can be performed safely in patients with ischemic cardiomyopathy with selective use of perioperative MCS. Despite advanced disease severity, patients requiring preoperative MCS demonstrate acceptable short- and long-term survival. Patients requiring postoperative MCS have increased postoperative morbidity and mortality.

Aortic insufficiency following balloon aortic valvuloplasty does not impact long-term autograft durability after the Ross procedure.

OBJECTIVE: Preoperative aortic insufficiency (AI) is associated with inferior autograft durability after the Ross procedure. However, many patients with aortic stenosis (AS) undergo balloon aortic valvuloplasty (BAV) early and present with longstanding AI before Ross. We studied how BAV and subsequent valvular pathology impacts autograft durability. METHODS: Patients undergoing the Ross operation from 1993 to 2020 were identified. Those who underwent BAV before Ross were compared with patients who did not undergo BAV and underwent Ross for predominant AI (AI group) or AS (AS group). Those who underwent previous open surgical aortic valve intervention were excluded. Primary outcome of interest was autograft failure, defined as a composite of autograft reintervention or severe insufficiency. RESULTS: A total of 198 patients were included. Seventy-nine (39.9%) underwent BAV and subsequently underwent the Ross for predominant AI (45.6%) or AS (54.4%). Of patients who did not undergo BAV, 66 (33.3%) presented with predominant AI and 53 (26.8%) with AS. Freedom from autograft failure at 15 years was 90%, 92%, and 62% in BAV, AS, and AI groups, respectively. The AI group was at significantly increased risk of long-term autograft failure (hazard ratio, 5.6; P = .01), whereas the AS and BAV groups had similar, low risk (hazard ratio, 1.1; P = .91). Autograft durability was similar among patients who received BAV and presented with AS or AI before the Ross (P = .84). CONCLUSIONS: BAV before the Ross procedure is common in patients with AS. These patients have excellent long-term autograft durability regardless of preoperative valvular pathology and should strongly be considered for the Ross operation.

Long-term autograft dilation and durability after the Ross procedure are similar in infants, children, and adolescents with primary aortic stenosis.

BACKGROUND: Autograft durability and remodeling are thought to be superior in younger pediatric patients after the Ross operation. We sought to delineate the fate of autografts across the pediatric age spectrum in patients with primary aortic stenosis (AS). METHODS: We retrospectively reviewed patients age ≤18 years with primary AS who underwent the Ross operation between 1993 and 2020. Patients were categorized by age. The primary endpoint was autograft dimensional change, and secondary endpoints were severe neo-aortic insufficiency (AI) and autograft reintervention. RESULTS: A total of 119 patients underwent the Ross operation, including 37 (31.1%) in group I (age <18 months), 24 (20.2%) in group II (age 18 months-8 years), and 58 (48.7%) in group III (age 8-18 years). All groups exhibited similar annular growth rates within the first 5 postoperative years, followed by a collective decrease in annulus growth rates from year 5 to year 10. Group III experienced rapid sinus dilation in the first 5 years, followed by stabilization of the sinus z-score from year 5 to year 10, whereas groups I and II demonstrated stable sinus z-scores over 10 years. There were 4 early deaths (3.4%) and 2 late deaths (1.7%) at a median follow-up of 8.1 years (range, 0.01-26.3 years). At 15 years, the incidences of severe neo-AI (0.0 ± 0.0% vs 0.0 ± 0.0% vs 3.9 ± 3.9%; P = .52) and autograft reintervention (8.4 ± 6.0% vs 0.0 ± 0.0% vs 2.4 ± 2.4%; P = .47) were similar in the 3 groups. CONCLUSIONS: Age at the time of Ross operation for primary AS does not influence long-term autograft remodeling or durability. Other physiologic or technical factors are likely greater determinants of autograft fate.

Influence of preoperative aortic regurgitation on long-term autograft durability and dilatation in children and adolescents undergoing the Ross procedure.

OBJECTIVE: Primary aortic insufficiency (AI) is a risk factor for autograft reintervention in adults undergoing the Ross procedure. We sought to examine the influence of preoperative AI on autograft durability in children and adolescents. METHODS: From 1993 to 2020, 125 consecutive patients between ages 1 and 18 underwent a Ross procedure. The autograft was implanted using a full-root technique in 123 (98.4%) and included in a polyethelene terephthalate graft in 2 (1.6%). Patients with aortic stenosis (aortic stenosis group) (n = 85) were retrospectively compared with those with AI or mixed disease (AI group) (n = 40). Median length of follow-up was 8.2 years (interquartile range, 3.3-15.4 years). The primary end point was the incidence of severe AI or autograft reintervention. Secondary end points included changes in autograft dimensions analyzed using mixed-effect models. RESULTS: The incidence of severe AI or autograft reintervention was 39.0% ± 13.0% in the AI group and 8.8% ± 4.4% in the aortic stenosis group at 15 years (P = .02). Annulus z scores increased in both aortic stenosis and AI groups over time (P < .001). However, the annulus dilated at a faster rate in the AI group (absolute difference, 3.8 ± 2.0 vs 2.5 ± 1.7; P = .03). Sinus of Valsalva z scores increased in both groups as well (P < .001), but at similar rates over time (P = .11). CONCLUSIONS: Children and adolescents with AI undergoing the Ross procedure have higher rates of autograft failure. Patients with preoperative AI have more pronounced dilatation at the annulus. Akin to adults, a surgical aortic annulus stabilization technique that modulates growth is needed in children.

Increasing waiting times for status 2 patients in new United Network for Organ Sharing allocation system: Impact on waitlist and posttransplant outcomes.

OBJECTIVE: Since the heart transplant allocation policy change in 2018, there has been an increase in temporary mechanical circulatory support for Status 2 patients. We sought to examine the temporal pattern of waitlist and posttransplant outcomes for Status 2 patients. METHODS: Adult patients in the United Network for Organ Sharing registry who were listed as Status 2 from January 2019 to June 2022 were included. Temporal trends in waitlist time, waitlist events, and posttransplant outcomes were assessed. Probability of transplant or death after being listed was compared over time. Multivariable regression was performed to identify risk factors for mortality after transplant. RESULTS: A total of 6310 patients were included. From 2019 to 2022, the number of Status 2 patients listed increased from 4.2 to 5.9 per day. Microaxial ventricular assist devices at Status 2 listing increased over time (P < .001). During the study period, median waitlist time (18 days vs 23 days, P < .001) as well as Status 2 days (8 days vs 12 days, P < .001) increased. Waitlist mortality remained stable (5.5%); however, probability of transplant within 90 days of Status 2 listing progressively declined (P < .001). Finally, longer waitlist duration was independently associated with 30-day posttransplant mortality (odds ratio, 1.01; 95% confidence interval, 1.00-1.01, P = .02). CONCLUSIONS: Since the allocation policy change there has been a steady rise in the number of patients listed for Status 2. This has led to increasing waitlist times and lower probability of transplantation for Status 2 patients, which may have negative consequences for posttransplant outcomes.

Reintervention after valve-sparing aortic root replacement: A comprehensive analysis of 781 David V procedures.

OBJECTIVE: Studies of reintervention after valve-sparing aortic root replacement (VSRR) are limited by sample size and failure to evaluate all types of reinterventions, including distal aorta and transcatheter interventions. In this report, reintervention after VSRR using a large patient cohort was comprehensively analyzed. METHODS: In a series involving 2 academic aortic centers, 781 consecutive patients from 2005 to 2020 undergoing David V VSRR for aortic aneurysm (91%) or dissection (9%) were included. Median age was 50 years, and 23% had a bicuspid aortic valve (AV). Median follow-up was 7.0 years. Open or transcatheter reintervention on the AV, proximal, or distal thoracic aorta was identified. Cumulative incidence was calculated, and subdistribution hazard models identified factors associated with reintervention. Time-dependent incidence of reintervention was plotted using risk-hazard functions. RESULTS: Sixty-eight reinterventions (57 open, 11 transcatheter) were performed. Reinterventions were divided by indication into degenerative AV (n = 26, including 1 transcatheter aortic valve replacement), endocarditis (n = 11), proximal aorta (n = 8), and distal aorta (n = 23, including 10 thoracic endovascular aortic repairs). Risk of reintervention for endocarditis peaked 1 to 3 years after VSRR, whereas other indications had stable, low rates of occurrence throughout the follow-up period. The cumulative incidence of reintervention was 12.5% whereas the cumulative incidence of AV reintervention was 7.0% at 10 years and was associated with residual postoperative aortic insufficiency. In-hospital mortality after reintervention was 3%. CONCLUSIONS: Reintervention rates after VSRR are relatively low in long-term follow-up and can be performed with acceptable operative risk. The majority of reinterventions are performed for indications other than AV degeneration, with the timing of reintervention varying by the specific clinical indication.

Noncoding mutations cause super-enhancer retargeting resulting in protein synthesis dysregulation during B cell lymphoma progression.

Whole-genome sequencing of longitudinal tumor pairs representing transformation of follicular lymphoma to high-grade B cell lymphoma with MYC and BCL2 rearrangements (double-hit lymphoma) identified coding and noncoding genomic alterations acquired during lymphoma progression. Many of these transformation-associated alterations recurrently and focally occur at topologically associating domain resident regulatory DNA elements, including H3K4me3 promoter marks located within H3K27ac super-enhancer clusters in B cell non-Hodgkin lymphoma. One region found to undergo recurrent alteration upon transformation overlaps a super-enhancer affecting the expression of the PAX5/ZCCHC7 gene pair. ZCCHC7 encodes a subunit of the Trf4/5-Air1/2-Mtr4 polyadenylation-like complex and demonstrated copy number gain, chromosomal translocation and enhancer retargeting-mediated transcriptional upregulation upon lymphoma transformation. Consequently, lymphoma cells demonstrate nucleolar dysregulation via altered noncoding 5.8S ribosomal RNA processing. We find that a noncoding mutation acquired during lymphoma progression affects noncoding rRNA processing, thereby rewiring protein synthesis leading to oncogenic changes in the lymphoma proteome.

Valved Conduits for Right Ventricular Outflow Tract Reconstruction: A Review of Current Technologies and Future Directions.

The need for right ventricular outflow tract reconstruction is common and growing in congenital heart surgery given expanding indications for the repair of congenital as well as acquired heart disease. Various valved conduit options currently exist including homografts, xenograft pulmonary valved conduits (Contegra™), and porcine valved conduits. The major limitation for all conduits is implant durability, which requires reoperation. Currently, cryopreserved homografts are often used given their superiority shown in long-term data. Significant limitations remain in the cost and availability of the graft, particularly for smaller sizes. Contegra conduits are available in a variety of sizes. Nonetheless, the data regarding long-term durability are less robust and studies comparing durability with homografts have been conflicting. Additionally, there is concern for increased rates of late endocarditis in this conduit. Porcine valved conduits offer a reliable option but are limited by structural valve degeneration associated with all types of bioprosthetic heart valve replacements. New developments in the field of tissue engineering have produced promising bio-restorative valved conduits that may overcome many of the limitations of previous conduit technologies. These remain in the early stages of clinical testing. This review summarizes the clinical data surrounding the conduits used most commonly in clinical practice today and explores emerging technologies that may bring us closer to developing the ideal conduit.

Valve-sparing aortic root replacement versus composite valve graft with bioprosthesis in patients under age 50.

BACKGROUND: Although the unique risks of implanting a prosthetic valve after aortic valve (AV) surgery in young patients are well established, studies of aortic root replacement (ARR) are lacking. We investigated long-term outcomes after valve-sparing root replacement (VSRR) versus the use of a composite valve graft with bioprosthesis (b-CVG) in patients age <50 years. METHODS: A total of 543 patients age <50 years underwent VSRR (n = 335) or b-CVG (n = 208) between 2004 and 2021 from 2 aortic centers, excluding those with dissection or endocarditis. Endpoints included mortality over time, reoperative aortic valve replacement (AVR), and development of greater than moderate aortic insufficiency (AI) or aortic stenosis (AS). Fine and Gray competing risk regression was used to compare the risk of reintervention. Propensity score matching (PSM) balanced patient comorbidities, and landmark analysis isolated outcomes beginning 4 years postoperatively. RESULTS: Compared with VSRR, b-CVG was associated with lower 12-year survival (88.6% vs 92.9%; P = .036) and a higher rate of AV reintervention (37.6% vs 12.0%; P = .018). After PSM, survival was similar in the 2 arms (93.4% for b-CVG vs 93.0% for VSRR; P = .72). However, both Fine and Gray multivariable risk regression and PSM showed that b-CVG was independently associated with AV reintervention at >4 years postoperatively (Fine and Gray: subdistribution hazard ratio, 4.3 [95% confidence interval, 1.8-10.2; P = .001]; PSM: 35.7% for b-CVG versus 14.3% for VSRR; P = .024]). PSM rates of greater than moderate AI/AS at 10 years were more than 2-fold greater in the b-CVG arm compared with the VSRR arm (37.1% vs 15.9%; P = .571). CONCLUSIONS: b-CVG in young patients is associated with early valvular degeneration, with increasing rates of reoperative AVR occurring even within 10 years. In contrast, VSRR is durable with excellent survival. In eligible young patients, every effort should be made to retain the native AV.

Modeling the dispersion of traffic-derived black carbon emissions into hilly terrain.

This study examines hilly terrain's effect on black carbon (BC) dispersion. The apportionment of distinct sources obtained by a two-component mixing model (Aethalometer: AE-33) using improved radiative transfer equations showed the dominance of traffic-derived black carbon (BCFF) emissions in the study region. The AERMOD was used to model BC emissions from moving traffic as a line source and parking lot as area source using observational and WRF-processed meteorology for the winter (January to March 2020). The model results showed that the BC levels substantially vary with local meteorological conditions, traffic volume, and composition. The hilly terrain obstructs the winds and develops a negative pressure loading to a vacuum on the other side of the hills, which promotes the accumulation of emissions, causing high BC concentrations. The pockets of higher concentration were seen at the locations where steep slopes were associated with low winds (<1 m s-1) and hill fogs. The AERMOD model, after statistical evaluation against the observational datasets, has been applied to study the reduction in BCFF concentrations due to the implementation of Indian emission norms as mitigation measures, i.e., BS-IV (equivalent to Euro 4) and BS-VI (equivalent to Euro 6). It was found that the BCFF concentrations for BS-IV and BS-VI reduced by 35% and 75%, respectively. The model was also used to study the contribution of the different vehicular categories to BC concentration.

New system, old problem: Increased wait time for high-priority transplant candidates.

The 2018 heart allocation policy sought to improve risk stratification and reduce waitlist mortality for the sickest patients. This study sought to evaluate changes in wait times for the highest priority patients since policy implementation. All adult single-organ transplant recipients were identified in the United Network for Organ Sharing registry from October 18, 2018, to July 8, 2022, and separated into 4 periods. Outcomes were compared by blood type and UNOS region. Over the study period, 897 of 9,143 patients were listed as status 1 with no significant change in median wait time by blood type or region. More patients were listed as status 2 (4,523/9,143), and each subsequent period postpolicy change was associated with a 4.2-day increase in mean status 2 waitlist time (95% confidence interval 3.0-5.5, p < 0.0001). Wait times were longest for candidates with blood type O and shortest for AB & A. Regional variations continued, however, wait time increased in every region over time.

Adoption of machine learning algorithm for predicting the length of stay of patients (construction workers) during COVID pandemic.

The construction sector in a rapidly developing country like India is a very unorganized sector. A large number of workers were affected and hospitalized during the pandemic. This situation is costing the sector heavily in several respects. This research study was conducted as part of using machine learning algorithms to improve construction company health and safety policies. LOS (length of stay) is used to predict how long a patient will stay in a hospital. Predicting LOS is very useful not only for hospitals, but also for construction companies to measure resources and reduce costs. Predicting LOS has become an important step in most hospitals before admitting patients. In this post, we used the Medical Information Mart for Intensive Care(MIMIC III) dataset and applied four different machine learning algorithms: decision tree classifier, random forest, Artificial Neural Network (ANN), and logistic regression. First, I performed data pre-processing to clean up the dataset. In the next step, we performed function selection using the Select Best algorithm with an evaluation function of chi2 to perform hot coding. We then performed a split between training and testing and applied a machine learning algorithm. The metric used for comparison was accuracy. After implementing the algorithms, the accuracy was compared. Random forest was found to perform best at 89%. Afterwards, we performed hyperparameter tuning using a grid search algorithm on a random forest to obtain higher accuracy. The final accuracy is 90%. This kind of research can help improve health security policies by introducing modern computational techniques, and can also help optimize resources.

MasR and pGCA receptor activation protects primary vascular smooth muscle cells and endothelial cells against oxidative stress via inhibition of intracellular calcium.

Cardiovascular diseases (CVDs) are associated with vascular smooth muscle cell (VSMC) and endothelial cell (EC) damage. Angiotensin1-7 (Ang1-7) and B-type natriuretic peptide (BNP) are responsible for vasodilation and regulation of blood flow. These protective effects of BNP are primarily mediated by the activation of sGCs/cGMP/cGKI pathway. Conversely, Ang1-7 inhibits Angiotensin II-induced contraction and oxidative stress via Mas receptor activation. Thus, the aim of the study was to determine the effect of co-activation of MasR and particulate guanylate cyclase receptor (pGCA) pathways by synthesized novel peptide (NP) in oxidative stress-induced VSMCs and ECs. MTT and Griess reagent assay kits were used for the standardization of the oxidative stress (H2 O2 ) induced model in VSMCs. The expression of targeted receptors in VSMC was done by RT-PCR and Western blot analysis. Protective effect of NP in VSMC and EC was determined by immunocytochemistry, FACS analysis, and Western blot analysis. Underlying mechanisms of EC-dependent VSMC relaxation were done by determining downstream mRNA gene expression and intracellular calcium imaging of cells. Synthesized NP significantly improved oxidative stress-induced injury in VSMCs. Remarkably, the actions of NP were superior to that of the Ang1-7 and BNP alone. Further, a mechanistic study in VSMC and EC suggested the involvement of upstream mediators of calcium inhibition for the therapeutic effect. NP is reported to possess vascular protective activities and is also involved in the improvement of endothelial damage. Moreover, it is highly effective than that of individual peptides BNP and Ang1-7 and therefore it may represent a promising strategy for CVDs.

Polymeric prosthetic heart valves: A review of current technologies and future directions.

Valvular heart disease is an important source of cardiovascular morbidity and mortality. Current prosthetic valve replacement options, such as bioprosthetic and mechanical heart valves are limited by structural valve degeneration requiring reoperation or the need for lifelong anticoagulation. Several new polymer technologies have been developed in recent years in the hope of creating an ideal polymeric heart valve substitute that overcomes these limitations. These compounds and valve devices are in various stages of research and development and have unique strengths and limitations inherent to their properties. This review summarizes the current literature available for the latest polymer heart valve technologies and compares important characteristics necessary for a successful valve replacement therapy, including hydrodynamic performance, thrombogenicity, hemocompatibility, long-term durability, calcification, and transcatheter application. The latter portion of this review summarizes the currently available clinical outcomes data regarding polymeric heart valves and discusses future directions of research.