Predictors for New-Onset Complete Heart Block After Transcatheter Aortic Valve Implantation

ObjectivesThe aim of this study was to identify risk factors for new-onset atrioventricular (AV) block requiring pacemaker (PM) implantation after transcatheter aortic valve implantation (TAVI).BackgroundHigh-grade AV block and consecutive PM implantation are frequent complications following TAVI.MethodsFor logistic regression analysis, we included 159 patients (mean age: 81 ± 6 years, EuroSCORE: 22 ± 13%) who underwent TAVI (n = 116 transfemoral, n = 4 via subclavian artery, n = 37 transapical, n = 2 transaortic) between June 2007 and January 2009 and who had no previously implanted PM.ResultsThirty-five patients (22%) developed new-onset post-operative AV block with the need of PM implantation. Logistic regression revealed a 2-fold increased risk for new-onset AV block in patients in whom a large valve is implanted in a small annulus (32% pacemaker implantations, odds ratio [OR]: 2.378, p = NS), a 4-fold increased risk with the implantation of the CoreValve (Medtronic, Minneapolis, Minnesota) versus the Edwards Sapien valve (Edwards Lifesciences, Irvine, California) (27% pacemaker implantations, OR: 3.781, p = NS), and a 5-fold increased risk for patients who exhibit an AV block episode instantly during the implantation procedure (49% pacemaker implantations, OR: 4.819, p = 0.001). Pre-existing ECG alterations were not identified as risk factors for AV block after transcatheter aortic valve implantation.ConclusionsWe assume that conduction tissue impairment is provoked by mechanical compression with large prostheses in smaller annuli or in the larger area of the CoreValve covering the outflow tract and may appear instantly during the implantation procedure. Continuous post-operative electrocardiogram monitoring should be performed for at least 3 days in all patients after TAVI procedures and until discharge in patients with increased risk for this complication

Biogenic polymer-based patches for congenital cardiac surgery: a feasibility study.

OBJECTIVE Currently used patch materials in congenital cardiac surgery do not grow, renew, or remodel. Patch calcification occurs more rapidly in pediatric patients eventually leading to reoperations. Bacterial cellulose (BC) as a biogenic polymer offers high tensile strength, biocompatibility, and hemocompatibility. Thus, we further investigated the biomechanical properties of BC for use as patch material. METHODS The BC-producing bacteria Acetobacter xylinum were cultured in different environments to investigate optimal culturing conditions. For mechanical characterization, an established method of inflation for biaxial testing was used. The applied static pressure and deflection height of the BC patch were measured. Furthermore, a displacement and strain distribution analysis was performed and compared to a standard xenograft pericardial patch. RESULTS The examination of the culturing conditions revealed that the BC became homogenous and stable when cultivated at 29°C, 60% oxygen concentration, and culturing medium exchange every third day for a total culturing period of 12 days. The estimated elastic modulus of the BC patches ranged from 200 to 530 MPa compared to 230 MPa for the pericardial patch. The strain distributions, calculated from preloaded (2 mmHg) to 80 mmHg inflation, show BC patch strains ranging between 0.6% and 4%, which was comparable to the pericardial patch. However, the pressure at rupture and peak deflection height varied greatly, ranging from 67 to around 200 mmHg and 0.96 to 5.28 mm, respectively. The same patch thickness does not automatically result in the same material properties indicating that the manufacturing conditions have a significant impact on durability. CONCLUSIONS BC patches can achieve comparable results to pericardial patches in terms of strain behavior as well as in the maximum applied pressure that can be withstood without rupture. Bacterial cellulose patches could be a promising material worth further research

Endothelial Progenitor Cells as Biomarkers of Cardiovascular Pathologies: A Narrative Review

Endothelial progenitor cells (EPC) may influence the integrity and stability of the vascular endothelium. The association of an altered total EPC number and function with cardiovascular diseases (CVD) and risk factors (CVF) was discussed; however, their role and applicability as biomarkers for clinical purposes have not yet been defined. Endothelial dysfunction is one of the key mechanisms in CVD. The assessment of endothelial dysfunction in vivo remains a major challenge, especially for a clinical evaluation of the need for therapeutic interventions or for primary prevention of CVD. One of the main challenges is the heterogeneity of this particular cell population. Endothelial cells (EC) can become senescent, and the majority of circulating endothelial cells (CEC) show evidence of apoptosis or necrosis. There are a few viable CECs that have properties similar to those of an endothelial progenitor cell. To use EPC levels as a biomarker for vascular function and cumulative cardiovascular risk, a correct definition of their phenotype, as well as an update on the clinical application and practicability of current isolation methods, are an urgent priority. Keywords: biomarker; cardiovascular disease; endothelial cells; progenitor

Endothelial Progenitor Cells as Biomarkers of Cardiovascular Pathologies: A Narrative Review

Endothelial progenitor cells (EPC) may influence the integrity and stability of the vascular endothelium. The association of an altered total EPC number and function with cardiovascular diseases (CVD) and risk factors (CVF) was discussed; however, their role and applicability as biomarkers for clinical purposes have not yet been defined. Endothelial dysfunction is one of the key mechanisms in CVD. The assessment of endothelial dysfunction in vivo remains a major challenge, especially for a clinical evaluation of the need for therapeutic interventions or for primary prevention of CVD. One of the main challenges is the heterogeneity of this particular cell population. Endothelial cells (EC) can become senescent, and the majority of circulating endothelial cells (CEC) show evidence of apoptosis or necrosis. There are a few viable CECs that have properties similar to those of an endothelial progenitor cell. To use EPC levels as a biomarker for vascular function and cumulative cardiovascular risk, a correct definition of their phenotype, as well as an update on the clinical application and practicability of current isolation methods, are an urgent priority

Impact of home monitoring program on interstage mortality after the Norwood procedure

ObjectiveWhile early outcome after the Norwood operation for hypoplastic left heart syndrome has improved, interstage mortality until bidirectional cavopulmonary shunt (BCPS) remains a concern. Our aim was to institute a home monitoring program to (HMP) decrease interstage mortality.MethodsAmong 264 patients who survived Norwood procedure and were discharged before BCPS, 80 patients were included in the HMP and compared to the remaining 184 patients regarding interstage mortality. In patients with HMP, events during the interstage period were evaluated.ResultsInterstage mortality was 8% (n = 21), and was significantly lower in patients with HMP (2.5%, n = 2), compared to those without (10.3%, n = 19, p = 0.031). Patients with interstage mortality had significantly lower birth weight (p < 0.001) compared to those without. Lower birth weight (p < 0.001), extra corporeal membrane oxygenation support (p = 0.002), and lack of HMP (p = 0.048) were risk factors for interstage mortality. Most frequent event during home monitoring was low saturation (<70%) in 14 patients (18%), followed by infection in 6 (7.5%), stagnated weight gain in 5 (6.3%), hypoxic shock in 3 (3.8%) and arrhythmias in 2 (2.5%). An unexpected readmission was needed in 24 patients (30%). In those patients, age (p = 0.001) and weight at BCPS (p = 0.007) were significantly lower compared to those without readmission, but the survival after BCPS was comparable between the groups.ConclusionsInterstage HMP permits timely intervention and led to an important decrease in interstage mortality. One-third of the patients with home monitoring program needed re-admission and demonstrated the need for earlier stage 2 palliation

Improvement in long-term survival after hospital discharge but not in freedom from reoperation after the change from atrial to arterial switch for transposition of the great arteries

ObjectiveTo compare survival, freedom from reoperation, and functional status between atrial switch and arterial switch operations for transposition of the great arteries.MethodsData from 88, 329, and 512 patients who underwent Mustard, Senning, and arterial switch operations between 1974 and 2006 were analyzed.ResultsIn-hospital mortalities were 8.0% for Mustard, 4.6% for Senning, and 6.4% for arterial switch. Presence of ventricular septal defect (hazard ratio 3.3, P < .001) was the only risk factor for in-hospital mortality in multivariate analysis. Follow-up for Mustard was 22.6 ± 8.1 years, for Senning was 18.2 ± 5.7 years, and for arterial switch was 9.5 ± 5.7 years. Highest survival at 20 years was after arterial switch (96.6% ± 1.3%), followed by Senning (92.6% ± 1.5%) and Mustard (82.4% ± 4.3%). Transposition with ventricular septal defect (hazard ratio 3.1, P < .001), transposition with ventricular septal defect and left ventricular outflow tract obstruction (hazard ratio 3.0, P = .029), and Mustard operation (hazard ratio 2.1, P = .011) emerged as risk factors for late death, with arterial switch a protective factor (hazard ratio 0.3, P = .010). Highest freedom from reoperation at 20 years was after Senning (88.7% ± 1.9%), followed by arterial switch (75.0% ± 6.4%) and Mustard (70.6% ± 5.4%). Presence of complex transposition (hazard ratio 2.1, P < .001), previous palliative operation (hazard ratio 1.8, P = .016), surgery between 1985 and 1995 (hazard ratio 2.6, P = .002), surgery after 1995 (hazard ratio 3.5, P < .001), and Mustard operation (hazard ratio 3.3, P < .001) emerged as risk factors for reoperation.ConclusionChange from atrial to arterial switch led to improved long-term survival after hospital discharge but not to lower incidence of reoperation. Survival and freedom from reoperation are determined by morphology

Case report: Central venous catheter thrombosis complicated by chronic thromboembolic disease/pulmonary hypertension in two children requiring parenteral nutrition

Chronic thromboembolic pulmonary hypertension is a rare but life-threatening complication of long-term central venous catheters (CVC) in children. However, evidence in terms of potential treatment strategies and outcome data remains scarce. We describe two cases of CVC-related thrombosis (Hickman-catheter) complicated by recurrent pulmonary emboli. One patient experienced a complete thromboembolic obstruction of the right pulmonary artery with normal pulmonary pressures and the second patient suffered from a central thromboembolic obstruction of both pulmonary arteries associated with severe pulmonary hypertension. Both patients successfully underwent surgical thromboendarterectomy with deep hypothermic circulatory arrest

Intraoperative renal near-infrared spectroscopy indicates developing acute kidney injury in infants undergoing cardiac surgery with cardiopulmonary bypass: a case-control study

Introduction: Acute kidney injury (AKI) is a frequent complication after cardiac surgery with cardiopulmonary bypass in infants. Renal near-infrared spectroscopy (NIRS) is used to evaluate regional oximetry in a non-invasive continuous real-time fashion, and reflects tissue perfusion. The aim of this study was to evaluate the relationship between renal oximetry and development of AKI in the operative and post-operative setting in infants undergoing cardiopulmonary bypass surgery. Methods: In this prospective study, we enrolled 59 infants undergoing cardiopulmonary bypass surgery for congenital heart disease for univentricular (n = 26) or biventricular (n = 33) repair. Renal NIRS was continuously measured intraoperatively and for at least 24 hours postoperatively and analysed for the intraoperative and first 12 hours, first 24 hours and first 48 hours postoperatively. The renal oximetry values were correlated with the paediatric risk, injury, failure, loss, end (pRIFLE) classification for AKI, renal biomarkers and the postoperative course. Results: Twenty-eight (48%) infants developed AKI based on pRIFLE classification. Already during intraoperative renal oximetry and further in the first 12 hours, 24 hours and 48 hours postoperatively, significantly lower renal oximetry values in AKI patients compared with patients with normal renal function were recorded (P < 0.05). Of the 28 patients who developed AKI, 3 (11%) needed renal replacement therapy and 2 (7%) died. In the non-AKI group, no deaths occurred. Infants with decreased renal oximetry values developed significantly higher lactate levels 24 hours after surgery. Cystatin C was a late parameter of AKI, and neutrophil gelatinase-associated lipocalin values were not correlated with AKI occurrence. Conclusion: Our results suggest that prolonged low renal oximetry values during cardiac surgery correlate with the development of AKI and may be superior to conventional biochemical markers. Renal NIRS might be a promising non-invasive tool of multimodal monitoring of kidney function and developing AKI in infants undergoing cardiac surgery with cardiopulmonary bypass