Neurovascular coupling in severe aortic valve stenosis.

OBJECTIVES: Aortic stenosis (AS) is characterized by obstruction of blood outflow from the left ventricle, which can impair target organ perfusion such as the brain. We hypothesized that hemodynamic changes in AS may lead to dysfunction of cerebral blood flow regulatory mechanisms. The aim of our study was to evaluate neurovascular coupling in patients with AS by Transcranial Doppler ultrasonography. METHODS: Neurovascular coupling was assessed using visually evoked cerebral blood flow velocity responses (VEFR) calculated as relative blood flow velocity changes in the posterior cerebral artery upon visual stimulation. We analyzed peak systolic, mean and end diastolic VEFR in 54 patients with severe AS and 43 controls in 10 consecutive cycles of visual stimulation. Repeated-measures ANOVA test was used to compare cerebral hemodynamic data by group. RESULTS: Patients with AS had significantly higher peak systolic (12.9% ± 5.6% and 10.5% ± 4.5%; p = .009) and mean VEFR (14.4% ± 5.8% and 12.2% ± 4.9%; p = .021) compared to controls, whereas only a tendency for higher end diastolic VEFR was observed (16.7% ± 6.9% and 14.4% ± 6.2%; p = .061). CONCLUSION: We have shown for the first time that patients with severe AS exhibit higher VEFR than controls indicating dysregulation of neurovascular coupling, which can be one of the factors contributing to development of cognitive decline.

Minimally invasive surgical aortic valve replacement versus transfemoral transcatheter aortic valve implantation in low-risk octogenarians : Observational, retrospective and single-center study.

BACKGROUND: The aim of this study was to compare short-term and mid-term outcomes in low-risk octogenarian population treated with transfemoral transcatheter aortic valve implantation (tf-TAVI) or minimally invasive aortic valve replacement (mini-AVR) for severe aortic stenosis. METHODS: In this single-center, retrospective cohort study we gathered data on low-risk (Society of Thoracic Surgeons [STS] score < 4%) octogenarians before and after tf-TAVI and mini-AVR performed between January 2013 and May 2019; follow-up was completed in May 2022. Short-term outcomes were hospital length of stay, in-hospital all-cause mortality and other major postoperative outcomes. Mid-term clinical outcomes were 1­year and 3­year all-cause mortality. Propensity score-based matching was performed. RESULTS: In total 106 patients were matched, resulting in 53 pairs. In-hospital complications were similar between the matched groups of patients with the exception of mild and moderate paravalvular leak (mini-AVR vs. tf-TAVI: mild PVL: 3.8% vs. 45.3%, p < 0.001; moderate PVL: 0% vs. 3.8%, p = 0.4952) and of postprocedural acute kidney injury that was more frequent in mini-AVR group (mini-AVR vs. tf-TAVI: 22.6% vs. 5.7%; p = 0.023). Hospital length of stay (p = 0.239) and in-hospital mortality (p = 0.495) did not differ between groups. The 1-year and 3­year all-cause mortality Kaplan-Meier estimates were similar between mini-AVR and tf-TAVI. CONCLUSION: In the present study on low-risk octogenarians, transfemoral TAVI and minimally invasive AVR showed comparable short-term and mid-term results. Both procedures are deemed safe and effective. Larger RCTs will be required to determine which low-risk patients will benefit most from TAVI.

Similar clinical outcomes with transcatheter aortic valve implantation and surgical aortic valve replacement in octogenarians with aortic stenosis.

Background: Transcatheter aortic valve implantation (TAVI) is the preferred treatment option for severe aortic stenosis in the elderly and in patients with comorbidities. We sought to compare outcomes after TAVI and surgical aortic valve replacement (SAVR) in octogenarians. Methods: In this retrospective cohort study conducted at our tertiary center, clinical data were gathered before and after TAVI and SAVR procedures performed from January 2013 to May 2019; follow-up completed in March 2021. The primary outcome was 1-year mortality. Patients were stratified according to Society of Thoracic Surgeons (STS) score and procedure type. Propensity score-based matching was also performed. Results: Of 542 patients who matched the inclusion criteria, 273 underwent TAVI and 269 SAVR. TAVI patients were older (85.8 ± 3.0 vs. 82.2 ± 2.2 years; P < 0.001) and had a higher mean STS score (5.0 ± 4.0 vs. 2.8 ± 1.3; P < 0.001) and EuroSCORE II (5.3 ± 4.1 vs. 2.8 ± 6.0; P < 0.001). Rates of postoperative permanent pacemaker insertion (15.0% vs. 9.3%; P = 0.040) and paravalvular leak (9.9% vs. 0.8%; P < 0.001) were higher and acute kidney injury lower (8.8% vs. 32.7%; P < 0.001) after TAVI, with no difference between treatment groups for major bleeding (11.0% vs. 6.7%; P = 0.130) or 30-day mortality (5.5% vs. 3.7%; P = 0.315). A statistically significant difference was found between TAVI and SAVR in low- and intermediate-risk groups when it came to occurrence of paravalvular leak, acute kidney injury, and new onset AF (all P < 0.001). Conclusion: This analysis of an octogenarian "real-life" population undergoing TAVI or SAVR (with a biological valve) showed similar outcomes regarding clinical endpoints in low- and medium-risk (STS score) groups.

Aortic valve leaflet and root dimensions in normal tricuspid aortic valves: A computed tomography study.

BACKGROUND AND AIM OF THE STUDY: The aim of this study was to use coronary computed tomography in patients with normal tricuspid aortic valves to perform detailed aortic root and aortic valve geometric analysis with a focus on the asymmetry of the three leaflets. METHODS: Retrospective analysis of anonymized coronary computed tomography angiograms was performed using dedicated software, where manual aortic root segmentation and marking of several points of interest were followed by automated measurements of aortic root and leaflets. Asymmetry of the three leaflets in individual patients was assessed by calculating absolute and relative differences between the largest and the smallest of the three leaflets. RESULTS: We analyzed 70 aortic valves, the mean patient age was 53 ± 11 years, and 50% (n = 35) of patients were female. All aortic valves were tricuspid, without calcifications and aortic roots were of normal dimensions. Some degree of asymmetry was present in all analyzed valves. Absolute and relative differences for free margin length were 3.2 ± 1.4 mm and 9.3 ± 3.8%, respectively. The largest relative difference was noted in the coaptation area (36.5 ± 16.5%) and the smallest in leaflet effective height (6.1 ± 4.8%). Using predefined cutoff criteria for absolute differences in leaflet dimensions, 86% of the valves were classified as asymmetric. CONCLUSIONS: Most normal tricuspid aortic valves show some degree of asymmetry. Equal free margin length of the three leaflets is not needed for normal tricuspid aortic valve function. Leaflet effective height showed the least amount of asymmetry confirming its importance in keeping the aortic valve competent.

Fluoroless catheter ablation of accessory pathways in adult and pediatric patients: a single centre experience.

Catheter radio-frequency ablation (RFA) and cryo-ablation (CRA) procedures are an effective and safe treatment options for adult and pediatric patients with accessory pathway (AP) mediated tachycardias. Non-fluoroscopic techniques during catheter ablation (CA) procedures reduce potentially harmful effects of radiation. Our aim was to investigate the efficacy and safety of completely fluoroless RFA and CRA procedures in pediatric and adult patients with APs. Consecutive patients with AP-related tachycardia and high risk asymptomatic ventricular pre-excitation were assessed in retrospective analysis. Three-dimensional (3D) electro-anatomical mapping (EAM) and intra-cardiac echocardiography (ICE) were used as principal imaging modalities. Fluoroscopy was not used during any stage of the procedures. Among 116 included patients (22.76 ± 16.1 years, 68 patients < 19 years), 60 had left-sided APs, 16 right-sided APs and 40 septal APs. Altogether, 96 had RFA and 20 CRA procedures. The acute success rates (ASR) of RFA and CRA were 97.9% and 95%, respectively (p = 0.43), with recurrence rates (RR) of 8.33% and 40%, respectively (p < 0.0001). The outcome difference was principally driven by lower RR with RFA in septal APs (9.1% vs. 38.9%, p = 0.025). Pediatric patients with APs (12.21 ± 3.76 years) had similar procedural parameters and outcomes compared to adult patients. There were no procedure-related complications. In adult and pediatric patients with AP-related tachycardias, both CRA and RFA can be effectively and safely performed without the use of fluoroscopy. In addition, RFA resulted in better outcomes compared to CRA.

Fluoroless radiofrequency and cryo-ablation of atrioventricular nodal reentry tachycardia in adults and children: a single-center experience.

BACKGROUND: Radiofrequency ablation (RFA) and cryo-ablation (CRA) have been traditionally performed with fluoroscopy which exposes patients and medical staff to the potential harmful effects of the X-ray. Therefore, we aimed to assess the feasibility, safety, and effectiveness of RFA and CRA of atrioventricular nodal reentry tachycardia (AVNRT) guided by the three-dimensional (3D) electro-anatomical mapping (EAM) system without the use of fluoroscopy. METHODS: We analyzed 168 consecutive patients with AVNRT, 62 of whom were under 19 years of age (128 in RFA (age 34.04 ± 21.0 years) and 40 in CRA (age 39.41 ± 22.8 years)). All procedures were performed completely without the use of the fluoroscopy and with the 3D EAM system. RESULTS: The acute success rates (ASR) of the two ablation methods were very high and similar (for RFA 126/128 (98.4%) and for CRA 40/40 (100%); p = 0.43). Total procedural time (TPT) was similar in RFA and CRA groups (75.04 ± 42.31 min and 73.12 ± 30.54 min, respectively; p = 0.79). Recurrence rates (1 (2.5%) and 8 (6.25%); p = 0.35) were similar. There were no complications associated with procedures in either group. In pediatric group, ASR (61/62 (98.38%) and 105/106 (99.05%), respectively; p = 0.69) and TPT (75.16 ± 42.2 min and 74.23 ± 38.3 min, respectively; p = 0.88) were similar to the adult group. High ASR was observed with both ablation methods (for RFA 49/50, 98%, and for CRA 12/12, 100%; p = 0.62] with very high arrhythmia-free survival rates (for RFA 98% and for CRA 100%; p = 0.62). CONCLUSION: Based on these results, it can be suggested that fluoroless RFA or CRA guided by the 3D EAM system can be routinely performed in all patients with AVNRT without compromising safety, efficacy, or duration of the procedure.

Intra-cardiac ultrasound guided approach for catheter ablation of typical right free wall accessory pathways.

BACKGROUND: Right free wall accessory pathways (AP) are difficult to treat with catheter ablation as ablation catheter (AC) instability at the tricuspid annulus often precludes successful procedure. The aim of our study was to test a novel intra-cardiac echocardiography (ICE) guided technique for AC placement. Feasibility and success rates were observed. METHODS: Eight consecutive patients (aged 29 ± 21 years, 4 female) with Wolff-Parkinson-White syndrome and a right free wall AP were included in the study. ICE, three-dimensional (3D) electro-anatomic mapping (EAM) system, and a steerable long sheath were used together with either an irrigated or a non-irrigated tip radio-frequency AC to achieve a "loop" manoeuvre which provided AC tip stability at the ventricular aspect of the tricuspid annulus. X-ray fluoroscopy was not used. RESULTS: Three patients had an anterior and five had a lateral location of the right free wall AP. Procedures were successful in all patients, without recurrences during the mean follow-up of 397 ± 363 days. Average procedural duration was 90 ± 31 min. On average, 6.6 ± 5.7 ablations were needed. Average time to terminate AP conduction after the start of ablation was 4.8 ± 4.2 s. In five patients (62%) AP conduction was successfully terminated with the first ablation. There were no procedural complications. CONCLUSIONS: The novel ICE-guided approach with concomitant use of the steerable sheath and the 3D EAM system for zero-fluoroscopy mapping and ablation of the right free wall APs proved feasible and resulted in excellent acute and long-term outcomes.

Combined use of electro-anatomic mapping system and intracardiac echocardiography to achieve zero-fluoroscopy catheter ablation for treatment of paroxysmal atrial fibrillation: a single centre experience.

Fluoroscopy is the principal imaging method for catheter ablation (CA) of atrial fibrillation (AF). However, radiation exposure carries potential health risk to patients and operators alike. Our aim was to study safety and efficacy of zero-fluoroscopy CA of paroxysmal AF with a combined use of electroanatomic mapping system (EAM) and intracardiac echocardiography (ICE). In addition, impact of ICE/EAM automatic integration system and contact force (CF) sensing technology on procedural times were assessed. We included 144 consecutive patients (69% males, age 60 ± 10 years, BMI 29 ± 4,6) referred for CA of symptomatic paroxysmal AF. All procedures were performed only with EAM system and ICE. No fluoroscopy was used. The acute procedural success of complete pulmonary vein isolation was achieved in all patients (100%) and adverse events were detected in eight patients (5.6%). In 53 (37%) patients the use of ICE/EAM automatic integration system shortened procedural times compared to those performed without it (148 ± 35 vs. 187 ± 44 min, p < 0.05). Similarly, 89 (60%) procedures where CF sensing catheter was used were shorter compared to those performed without it (163 ± 41 vs. 188 ± 46 min, p < 0.05). Zero-fluoroscopy approach for treatment of paroxysmal AF seems feasible, safe, and acutely effective. Additional reduction of procedural times could be achieved with the use of ICE/EAM automatic integration system and CF sensing technology.

Contribution of sonicate-fluid cultures and broad-range PCR to microbiological diagnosis in vascular graft infections.

BACKGROUND: Vascular graft infections (VGI) are associated with considerable morbidity and mortality, and antimicrobial treatment is an important adjunct to surgical treatment. While microbial aetiology of VGI is often difficult to determine, other techniques such as sonication of implanted material may be used to enhance the recovery of biofilm-associated organisms. METHODS: We performed a retrospective analysis of 22 consecutive patients treated for VGI at University Medical Centre Ljubljana from May 2011 through January 2015. Explanted vascular grafts were flooded with sterile Ringer solution, sonicated for 1 min at a frequency of 40 kHz and inoculated on solid and liquid culture media. Aerobic and anaerobic cultures were performed, incubated for 14 days and any significant bacterial growth was quantitatively evaluated. Additionally, broad-range PCR from sonicate fluid was performed. Microbiological results were compared with the results of preoperatively taken blood cultures and the results of intraoperative tissue cultures (material from peri-graft collection). RESULTS: Identification of the causative organism (irrespective of the method) was achieved in 95.8%. Preoperative blood cultures were positive in 35.3%, intraoperative tissue cultures in 31.8%, sonicate fluid culture in 79.2%, while broad-range PCR from sonicate fluid was positive in 66.7%. In 37.5% the pathogen detected in sonicate fluid culture or broad-range PCR was the only positive microbiological result. CONCLUSIONS: Sonicate fluid culture and broad-range PCR from explanted vascular grafts may contribute to optimization of antimicrobial treatment. Optimal timing of antibiotic therapy before explantation should be further assessed to improve diagnostic yield.

Perioperative erythropoietin protects the CNS against ischemic lesions in patients after open heart surgery.

AIM: The aim of this study was to establish erythropoietin as a protective factor against brain ischemia during open heart surgery. METHODS: A total of 36 consecutive patients scheduled for revascularization heart surgery were included in the study. Of the patients 18 received 3 intravenous doses of recombinant human erythropoietin (rHuEpo, 24,000 IU) and 18 patients received a placebo. Magnetic resonance imaging (MRI) to detect new brain ischemic lesions was performed. Additionally, S100A, S100B, neuron-specific enolase A and B (NSE-A and B) and the concentration of antibodies against N­methyl-D-aspartate receptors (NMDAR) to identify new neurological complications were determined. RESULTS: Patients who received rHuEpo showed no postoperative ischemic changes in the brain on MRI images. In the control group 5 (27.8 %) new ischemic lesions were found. The NMDAR antibody concentration, S100A, S100B and NSE showed no significant differences between the groups for new cerebral ischemia. High levels of lactate before and after external aortic compression (p = 0.022 and p = 0.048, respectively) and duration of operation could predict new ischemic lesions (p = 0.009). CONCLUSIONS: The addition of rHuEpo reduced the formation of lesions detectable by MRI in the brain and could be used clinically as neuroprotection in cardiac surgery.

Fluoroless catheter ablation of various right and left sided supra-ventricular tachycardias in children and adolescents.

Electrophysiology study (EPS) and catheter ablation (CA) in children and adolescents carries a potentially harmful effect of radiation exposure when performed with the use of fluoroscopy. Our aim was to evaluate the feasibility, safety and effectiveness of fluoroless EPS and CA of various supra-ventricular tachycardias (SVTs) with the use of the 3D mapping system and intracardiac echocardiography (ICE). Forty-three consecutive children and adolescents (age 13 ± 3 years) underwent fluoroless EPS and CA for various supra-ventricular tachycardias. A three-dimensional (3D) mapping system NavX™ was used for guidance of diagnostic and ablation catheters in the heart. ICE was used as a fundamental imaging tool for transseptal punctures. Acute procedural success rate was 100 %. There were no procedure related complications and short-term follow up (10 ± 3 months) revealed 93 % arrhythmia free survival rate. Fluoroless CA of various SVTs in the paediatric population is feasible, safe and can be performed successfully with 3D mapping system and ICE.

Transcatheter aortic valve implantation in a cancer patient denied for surgical aortic valve replacement-a case report.

BACKGROUND: Aortic stenosis is a progressive disease. Symptomatic aortic stenosis has a poor prognosis, which is frequently worse than that of a malignant disease. Cancer patients with severe aortic stenosis may be denied for optimal oncologic treatment because of high operative risk and for aortic valve replacement because of the significant comorbidity itself. In patients treated with medical therapy alone, 1-year-mortality exceeds 50 %. CASE REPORT: A 71-year-old woman with well-differentiated, surgically treated, ovarian carcinoma and two relapses treated with chemo- and radiotherapy presented with symptomatic severe aortic stenosis (aortic valve area 0.6 cm(2), mean gradient 60 mmHg). The tumor was in stagnation. She was rejected for surgical valve replacement. We implanted a 29 mm CoreValve aortic prosthesis via transfemoral approach. After the procedure haemodynamic variables remain stable, patient's exertional capacity is excellent. CONCLUSION: Aortic valve replacement improves survival of cancer patients with symptomatic aortic stenosis. Transcatheter aortic valve replacement (TAVI) is a treatment option in inoperable patients and patients at high surgical risk. Symptoms should not be confused for the progression of the malignant disease. In patient selection emphasis should be made on their frailty and futility. Eligible patients must have a life expectancy of at least 1 year. Final decision has to be made by a multidisciplinary heart team. TAVI can reduce treatment risk and facilitate the oncologic treatment.

Understanding coronary artery bypass transit time flow curves: role of bypass graft compliance.

OBJECTIVES: Low mean bypass graft flow (Q) and high pulsatility index (PI) measured by the transit time flow measurement method are not specific for anastomotic stenosis, but occur with competitive flow and poor coronary run-off. We hypothesized that graft compliance is responsible for these changes and that flow measured at the proximal end of the coronary bypass can be viewed as a sum of the graft capacitive flow and flow that passes through the distal anastomosis. METHODS: Transit time flow measurements (TTFMs) of 15 left internal thoracic artery (LITA) to LAD bypass grafts and 10 saphenous vein grafts (SVGs) to either the right coronary artery (RCA) or posterior descending artery (PDA) were analysed. The TTFM was performed on the proximal and distal end of the graft, and proximally with distal occlusion of the graft. Low mean bypass graft flow PI and diastolic filling (DF) measured distally and proximally were compared, and graft compliance was estimated. RESULTS: Diastolic filling was higher distally in every single case (LITA-LAD: distal DF 76 ± 12% vs proximal 66 ± 13%, P = 0.005; SVG-RCA/PDA: distal 72 ± 15% vs proximal 63 ± 12%, P = 0.018). There were no significant differences in Q and PI. Subtracting the distal from the proximal flow gave a result identical to the proximal TTFM in distally occluded grafts, confirming the presence of graft capacitive flow. Graft compliance estimated from the flow of distally occluded grafts was 0.99 ± 0.47 µl/mmHg for LITA grafts and 0.78 ± 0.42 µl/mmHg for SVG grafts. CONCLUSIONS: The study confirmed that the TTFM measured at the proximal end of the coronary bypass could be viewed as a sum of graft capacitive flow and the flow that passes through the distal anastomosis. Graft capacitive flow increases the systolic and decreases the diastolic TTFM when measured at the proximal end of the graft. It explains the higher DF when the TTFM is measured at the distal end of the graft and the increase in the PI at the proximal end when Q decreases. As the influence of graft capacitive flow on the PI in low Q can be eliminated by performing the TTFM at the distal end of the graft, we believe that the value of PI is clinically irrelevant.

Importance of erythropoietin in brain protection after cardiac surgery: a pilot study.

BACKGROUND: Neurologic complications after cardiac operations present an important medical problem, as well as a financial burden. They increase the morbidity and hospital stays of patients who have otherwise undergone successful heart operations. The current protocols for perioperative brain protection against ischemic events are not optimal. Because of its different pleiotropic mechanisms of action, recombinant human erythropoietin might provide neuroprotection. METHODS: In this study, we included 20 patients who were older than 18 years and required surgical revascularization of the heart with the use of the heart-lung machine. Ten patients received 3 consecutive intravenous doses (24,000 IU) of recombinant human erythropoietin (rHuEpo). Neurologic and magnetic resonance imaging (MRI) examinations were done before and in the first 5 days after surgery. RESULTS: The erythropoietin-treated and control groups were comparable with respect to study protocol outcomes: number of coronary artery bypass grafts (3.3 and 3.2 grafts/patient, respectively), operative time (4.12 and 4.6 hours), and transfusion volume per patient (708 and 674 mL). The groups were also comparable with respect to blood pressure values at all stages of the operation. MRI scans revealed that 4 of 10 patients from the control group had fresh ischemic brain lesions after open heart surgery. None of the patients in the erythropoietin-treated group had fresh ischemic brain lesions. CONCLUSION: Although the number of patients was small, the results regarding brain protection with rHuEpo are encouraging. rHuEpo is a promising neuroprotective agent.

Right ventricular metastatic choriocarcinoma obstructing inflow and outflow tract.

We operated on a 34-year-old man with a metastatic tumor that extended from the tricuspid valve to the pulmonary valve and obstructed the right ventricle inflow and outflow tracts. The tumor was removed with preservation of the tricuspid valve. Additional chemotherapy was carried out according to the BEPO (etoposid, eisplatin, bleomycin, vincritin) scheme. Histology revealed metastasis of a choriocarcinoma originating from the right testis. Computed tomography performed after 6 months detected no metastases in the lungs. Magnetic resonance imaging showed a thickened right ventricle free wall and apex. The patient is doing well 18 months postoperatively.