Atrioventricular Block after Tricuspid Valve Surgery.

Tricuspid valve (TV) surgery is associated with a high risk of postoperative pacemaker requirement. We set out to identify the incidence of atrioventricular block (AVB) after TV surgery and determine whether atrioventricular conduction recovers within time.We investigated pre/intra- and postoperative predictors of AVB in patients who underwent tricuspid valve surgery (not only isolated TV surgery) at our institution between 2004 and 2017. Patients who had pacemakers prior to surgery were excluded.One year after surgery, 5.8% of the surviving cohort had received a pacemaker due to AVB. In the complete follow-up time, 33 out of 505 patients required pacemaker implantation because of AVB. Of the 37 patients who presented to the intensive care unit postoperatively with AVB III, 14 (38%) underwent pacemaker implantation for AVB, and 20 (54%) did not require a pacemaker. AVB III at ICU admission was identified as a predictor of pacemaker implantation (OR: 9.7, CI: 3.8-24.5, P < 0.001). TV endocarditis was also identified as a predictor (OR: 12.4, CI: 3.3-46.3, P < 0.001). Eleven out of 32 patients (34%) with tricuspid endocarditis required a pacemaker for AVB. The mean ventricular pacing burden within the first 5 years after pacemaker implantation was 79%.The issue of AVB after TV surgery is significant. Both the initial rhythm after surgery and etiology of the tricuspid disease can help predict pacemaker requirement. Within the first 5 years after surgery, the ventricular pacing burden remains high without relevant rhythm recovery.

Thrombocytopenia and end stage renal disease are key predictors of survival in patients with cardiac implantable electronic device infections.

INTRODUCTION: Cardiac implantable electronic device (CIED) infections are associated with a high mortality. Our aim was to identify key predictors of survival in patients with CIED infections as to be able to detect high-risk patients and possibly affect modifiable factors. METHODS AND RESULTS: In this observational study, we collected data from 277 patients with CIED infections treated in our department between 2001 and 2017; predictors of survival were evaluated. The median time since the last CIED procedure was 0.83 years (interquartile range [IQR]: 0.25-3.01), median time since initial CIED implant was 4.79 years (IQR: 0.90-11.0 years). Survival at 30 days was 94.9% (95% confidence interval [CI]: 92.3-97.5) and survival at 1 year was 80.9% (CI: 76.4-85.7). Age (odds ratio [OR]: 1.05, CI: 1.01-1.09; P = .009), end stage renal disease (ESRD) with dialysis (OR: 5.14, CI: 1.87-14.11; P = .001), positive blood cultures (OR: 2.19, CI: 1.08-4.45; P = .030), and thrombocytopenia (OR: 2.3, CI, 1.03-5.15; P = .042) were identified as predictors of death within 1 year of treatment of CIED infection. CONCLUSION: Patients with CIED infection with prior ESRD with dialysis or preoperative thrombocytopenia are at an increased risk of 1-year mortality. We suggest that these patients be evaluated critically and resources be allocated to these patients more liberally. A greater understanding of the role of platelets in immunity may improve treatment of advanced infection in the future.

Pediatric heart transplantation-What are the risk factors for pacemaker implantation and how much pacing is required?

BACKGROUND: In an attempt to improve pacemaker therapy after pediatric transplantation, we investigated risk factors, indication for pacing, and pacing burden after pediatric heart transplantation. METHODS AND RESULTS: In this retrospective study, 139 pediatric heart transplant recipients, of whom 122 did not and 17 did require pacemakers, were investigated. Eleven of the 17 patients requiring a permanent pacemaker (PPM) received their heart from a female donor (68.8%); this compares to 48 of 122 patients (43.2%, P  =  0.082) in the group not requiring a pacemaker (No PPM). The donor age and height were significantly greater in the PPM group at a median of 25.26 years (16.29-48.00) and 160 cm (153-170) compared with 11.96 years (1.73-19.95) and 141 cm (89-165) in the No PPM group (P  =  0.003 and 0.015, respectively). Of the 17 patients requiring pacemakers, 13 presented with sinus node dysfunction (SND) and four with atrioventricular block. The atrial pacing burden in patients with SND remained above 60% within the 5 years of follow-up investigated. There was no significant difference in mortality between those patients requiring a PPM and those not (Log-Rank test: P  =  0.672). CONCLUSION: We found that in our cohort donor characteristics were key risk factors for pacemaker implantation in transplanted children. The data suggest that when patients require a pacemaker in posttransplant SND, they will require a relevant amount of pacing for at least 5 years. The pacing burden after this point remains to be investigated. Mortality does not differ between pediatric heart transplant patients with and without pacemakers.

A Single Center Study of 1,179 Heart Transplant Patients-Factors Affecting Pacemaker Implantation.

BACKGROUND: After around 10% of heart transplant patients require pacemaker implantation. The bradyarrhythmias causing pacemaker requirement include sinus node dysfunction (SND) and atrioventricular block (AVB). This study sought to define clinical predictors for pacemaker requirement as well as identify differences in the patient groups developing SND and AVB. METHODS: Our operative database was used to collect retrospective recipient, donor, and operative data of all patients receiving orthotopic heart transplants between 1981 and 2016. RESULTS: In the 35-year period 1,179 transplants were performed (mean recipient age 45.5 ± 0.5 years, 20.4% female, 90.6% biatrial technique) with bradyarrhythmias requiring pacemaker implantation developing in 135 patients (11.5%). Independent risk factors were prolonged operative time 340 minutes versus 313 minutes (P = 0.027) and a biatrial anastomosis (P = 0.036). Ischemia time, cardiopulmonary bypass time, aortic cross clamp time, and reperfusion time all had no significant effect on pacemaker implantation rates. Similarly, whether the transplant was a reoperation, a retransplant, or performed after primary assist implantation had no effects on pacemaker implantation rates. There was no survival difference between the paced and nonpaced groups. The donor age was higher in the patients who developed AVB as the indication for pacemaker implantation (43 vs 34 years, P = 0.031). Patients with AVB had longer aortic cross clamp times and developed the arrhythmia later than those who developed SND. CONCLUSIONS: Use of the bicaval instead of the biatrial technique and shortened operative times should reduce pacemaker requirement after heart transplantation. Survival is not affected by this complication.

New-onset atrial fibrillation after coronary surgery and stroke risk: a nationwide cohort study.

BACKGROUND: New-onset postoperative atrial fibrillation (POAF) after coronary artery bypass grafting (CABG) increases ischaemic stroke risk, yet factors influencing this risk remain unclear. We sought to identify factors associated with 1-year ischaemic stroke risk, compare the CHA2DS2-VASc (Congestive heart failure, Hypertension, Age ≥75 years, Diabetes, previous Stroke/transient ischaemic attack (TIA), Vascular disease, Age 65-74 years, Sex category) and ATRIA (Anticoagulation and Risk Factors in Atrial Fibrillation) scores' predictive abilities for ischaemic stroke, and assess oral anticoagulation (OAC) dispensing at discharge in patients with POAF. METHODS: This nationwide cohort study used prospectively collected data from four mandatory Swedish national registries. All first-time isolated CABG patients who developed POAF during 2007-2020 were included. Multivariable logistic models were used to identify ischaemic stroke predictors and C-statistics to assess the predictive abilities of the CHA2DS2-VASc and ATRIA scores in patients without OAC. OAC dispensing patterns were described based on stroke-associated factors. RESULTS: In total, 10 435 patients with POAF were identified. Out of those not receiving OAC (n=6903), 3.1% experienced an ischaemic stroke within 1 year. Advancing age (adjusted OR (aOR) 1.86 per 10-year increase, 95% CI 1.45 to 2.38), prior ischaemic stroke (aOR 18.56, 95% CI 10.05 to 34.28 at 60 years, aOR 5.95, 95% CI 3.78 to 9.37 at 80 years, interaction p<0.001), myocardial infarction (aOR 1.55, 95% CI 1.14 to 2.10) and heart failure (aOR 1.53, 95% CI 1.06 to 2.21) were independently associated with ischaemic stroke. The area under the receiver-operating characteristic curve was 0.72 (0.69-0.76) and 0.74 (0.70-0.78) for CHA2DS2-VASc and ATRIA, respectively (p=0.021). Altogether, 71.0% of patients with a stroke risk >2%/year, according to the CHA2DS2-VASc score, were not discharged on OAC. CONCLUSIONS: Prior ischaemic stroke, advancing age, history of heart failure and myocardial infarction were associated with 1-year ischaemic stroke risk in patients with POAF after CABG. CHA2DS2-VASc and ATRIA scores predicted stroke risk with similar accuracy as in non-surgical atrial fibrillation cohorts. OAC dispense at discharge does not seem to reflect individual stroke risk.

Evaluation of a rapid deployment prosthesis strategy for the treatment of aortic valve endocarditis.

OBJECTIVES: The aim of this study was to evaluate the surgical outcome of patients suffering from native aortic valve (NVE) or prosthetic aortic valve endocarditis (PVE) treated with the EDWARDS INTUITY Elite rapid-deployment valve prosthesis. METHODS: Between February 2019 and June 2020, 25 patients suffering from NVE (n = 9; 36%) and PVE (n = 16; 64%) of the aortic valve received an INTUITY valve at our institution. Preoperative, operative and follow-up data were collected. RESULTS: In our cohort, the mean EuroSCORE II was 13.4%. Eleven patients (44%) received concomitant aortic root patch plasty. Four patients (16%) received coronary artery bypass graft surgery, 3 patients (12%) received mitral valve repair and 2 patients (8%) underwent replacement of the ascending aorta. The cardiopulmonary bypass and aortic cross-clamp times were 124 ± 56 and 75 ± 39 min, respectively. The mean intensive care unit stay was 5 days. The mean size of the implanted prostheses was 25 ± 2 mm and the mean prosthesis transvalvular gradient 3 months after surgery was 9 ± 4 mmHg. During follow-up, no case of recurrent endocarditis occurred, 1 patient died of multisystem organ failure which had already been present preoperatively. CONCLUSIONS: Surgery for NVE and PVE of the aortic valve may be safely performed using the EDWARDS INTUITY Elite valve system. This procedure could be well implemented in cases with extensive infection, fragile root tissue and root abscesses requiring root reconstruction. In our institution, the rapid-deployment aortic valve replacement strategy has become an important tool in the armamentarium of the surgical endocarditis treatment.

Autologous endothelialized vein allografts in coronary artery bypass surgery - Long term results.

BACKGROUND: Lack of autologous graft material restricts the ability to treat patients requiring coronary artery bypass surgery (CABG). An off the shelf tissue engineered small diameter vascular graft is the holy grail of cardiovascular surgery. METHODS: Allograft saphenous veins were harvested from organ donors, cryopreserved, deendothelialized and then seeded with autologous endothelial cells prior to implantation during coronary artery bypass surgery. All patients treated were followed-up until death and angiographic results were collected. Grafts were explanted during autopsy and immunohistochemistry was performed. RESULTS: Twelve patients received 15 engineered grafts. Mean patient survival was 9.1 ±â€¯1.8 years. Six month graft patency was 80 (95% CI: 59-100) and 9 month graft patency was 50 (95% CI: 27-93) - graft patency detected up to 32 months after surgery. Immunohistochemistry in grafts explanted showed a presence of CD31 and CD68 positive cells in the luminal region of the vessel walls and layers of Collagen Type I in the abluminal vessel walls. CONCLUSIONS: Our small diameter tissue engineered vascular graft shows openness up to 32 months after implantation. Immunohistochemistry suggests that monocyte activation may lead to vessel remodeling with thickening of the vessel wall. Research should concentrate on a manipulation of remodeling processes.

A feasibility study of a multimodal stimulation bioreactor for the conditioning of stem cell seeded cardiac patches via electrical impulses and pulsatile perfusion.

BACKGROUND/OBJECTIVE: Ischemic heart disease is a major cause of mortality worldwide. Myocardial tissue engineering aims to create transplantable units of myocardium for the treatment of myocardial necrosis caused by ischemic heart disease - bioreactors are used to condition these bioartificial tissues before application. METHODS: Our group developed a multimodal bioreactor consisting of a linear drive motor for pulsatile flow generation (500 ml/min) and an external pacemaker for electrical stimulation (10 mA, 3 V at 60 Hz) using LinMot-Talk Software to synchronize these modes of stimulation. Polyurethane scaffolds were seeded with 0.750 × 106 mesenchymal stem cells from umbilical cord tissue per cm2 and stimulated in our system for 72 h, then evaluated. RESULTS: After conditioning histology showed that the patches consisted of a cell multilayer surviving stimulation without major damage by the multimodal stimulation, scanning electron microscopy showed a confluent cell layer with no cell-cell interspaces visible. No cell viability issues could be identified via Syto9-Propidium Iodide staining. CONCLUSIONS: This bioreactor allows mechanical stimulation via pulsatile flow and electrical stimulation through a pacemaker. Our stem cell-polyurethane constructs displayed survival after conditioning. This system shows feasibility in preliminary tests.