Ventricular Arrhythmias in Left Ventricular Assist Device Patients-Current Diagnostic and Therapeutic Considerations.

Left ventricular assist devices (LVAD) are used in the treatment of advanced left ventricular heart failure. LVAD can serve as a bridge to orthotopic heart transplantation or as a destination therapy in cases where orthotopic heart transplantation is contraindicated. Ventricular arrhythmias are frequently observed in patients with LVAD. This problem is further compounded as a result of diagnostic difficulties arising from presently available electrocardiographic methods. Due to artifacts from LVAD-generated electromagnetic fields, it can be challenging to assess the origin of arrhythmias in standard ECG tracings. In this article, we will review and discuss common mechanisms, diagnostics methods, and therapeutic strategies for ventricular arrhythmia treatment, as well as numerous problems we face in LVAD implant patients.

ARTERIAL HYPEROXIA AND MORTALITY IN PATIENTS UNDERGOING VENOARTERIAL EXTRACORPOREAL MEMBRANE OXYGENATION.

ABSTRACT: Background: Venoarterial extracorporeal membrane oxygenation (VA-ECMO) can easily lead to supranormal oxygenation. The impact of hyperoxygenation beyond the early VA-ECMO support phase is unexplored. We sought to investigate its association with short- and long-term mortality. Methods: A total of 10,615 arterial blood gases of 179 patients undergoing VA-ECMO between 2013 and 2018 in our cardiosurgical tertiary center were analyzed for partial pressure of oxygen (PaO2) and its association with in-hospital, 90-day, and 1-year mortality. Patients were stratified into terciles (T) based on PaO2. Results: The median systemic PaO2 during VA-ECMO was 122 mm Hg (Q1-Q3, 111-158 mm Hg) and was significantly higher in 90-day nonsurvivors versus survivors (134 mm Hg [Q1-Q3, 114-175 mm Hg] vs. 114 mm Hg [Q1-Q3, 109-136 mm Hg]; P < 0.001). The incidence of mortality increased at all time points tested after VA-ECMO implantation along with the increasing terciles of PaO2. The lowest mortality rates were noted for patients with median PaO2 values of <115 mm Hg (T1), whereas patients with median PaO2 values of >144 mm Hg (T3) had the highest mortality rates. Bonferroni multiple testing analysis found the T3 of PaO2 to be a predictor of decreased 90-day survival in comparison with T1 (P < 0.001) and T2 (P = 0.002). Multivariable Cox regression analyses for in-hospital, 90-day, and 1-year mortality showed a significant association of the T3 compared with the T2 and the T1 of PaO2 to mortality across all endpoints. Conclusion: Hyperoxygenation during VA-ECMO might be associated with increased all-cause mortality. The results of our study further document the known toxicity of hyperoxygenation in general critical care patients and mark the need to focus specifically on VA-ECMO patients.

Troponin T and Survival following Cardiac Surgery in Patients Supported with Extracorporeal Membrane Oxygenation for Post-Cardiotomy Shock.

BACKGROUND: While troponin is an established biomarker of cardiac injury, its prognostic significance in post-cardiotomy cardiogenic shock patients supported by venoarterial extracorporeal membrane oxygenation (PCCS-VA-ECMO) remains unclear. OBJECTIVE: This study aimed to assess the correlation between early post-operative troponin T levels and both short-term and long-term mortality outcomes in this cohort. METHODS: We evaluated 1457 troponin T measurements from 102 PCCS-VA-ECMO patients treated from 2013 to 2018 at a specialized cardio-surgical and transplantation center. Emphasis was placed on troponin concentrations at 24-48 h post-surgery, post-VA-ECMO implantation, and peak troponin levels in relation to VA-ECMO weaning, as well as 90-day and one-year mortality. RESULTS: No significant association was observed between troponin T levels post-VA-ECMO implantation and 90-day mortality (median: 1338 ng/L for overall, 1529 ng/L for survivors vs. 1294 ng/L for non-survivors; p = 0.146) or between peak troponin levels and 90-day mortality (median: 3583 ng/L for overall, 3337 ng/L for survivors vs. 3666 ng/L for non-survivors; p = 0.709). Comprehensive multivariate models showed no correlation between troponin levels and various mortality endpoints. Notably, age, procedure urgency, type, LVEF pre-surgery, Euroscore II, prior cardiac arrest, and VA-ECMO duration were not linked with troponin release. Hemodiafiltration emerged as the strongest mortality risk factor [HR 2.4]. CONCLUSIONS: Isolated early Troponin T release and peak troponin T were not associated, while organ complications were linked with VA-ECMO weaning or short- and long-term prognosis. The results underscore the multi-organ implications of PCCS in determining survival.

Clinical and Molecular Aspects of Iron Metabolism in Failing Myocytes.

Heart failure (HF) is a common disease that causes significant limitations on the organism's capacity and, in extreme cases, leads to death. Clinically, iron deficiency (ID) plays an essential role in heart failure by deteriorating the patient's condition and is a prognostic marker indicating poor clinical outcomes. Therefore, in HF patients, supplementation of iron is recommended. However, iron treatment may cause adverse effects by increasing iron-related apoptosis and the production of oxygen radicals, which may cause additional heart damage. Furthermore, many knowledge gaps exist regarding the complex interplay between iron deficiency and heart failure. Here, we describe the current, comprehensive knowledge about the role of the proteins involved in iron metabolism. We will focus on the molecular and clinical aspects of iron deficiency in HF. We believe that summarizing the new advances in the translational and clinical research regarding iron deficiency in heart failure should broaden clinicians' awareness of this comorbidity.

Expression of Iron Metabolism Proteins in Patients with Chronic Heart Failure.

In heart failure, iron deficiency is a common comorbid disease that negatively influences exercise tolerance, number of hospitalizations and mortality rate, and this is why iron iv supplementation is recommended. Little is known about the changes in iron-related proteins in the human HF myocardium. The purpose of this study was to assess iron-related proteins in non-failing (NFH) vs. failing (FH) human myocardium. The study group consisted of 58 explanted FHs; control consisted of 31 NFHs unsuitable for transplantation. Myocardial proteins expressions: divalent metal transporter (DMT-1); L-type calcium channel (L-CH); transferrin receptors (TfR-1/TfR-2); ferritins: heavy (FT-H) or light (FT-L) chain, mitochondrial (FT-MT); ferroportin (FPN), regulatory factors and oxidative stress marker: 4-hydroxynonenal (4-HNE). In FH, the expression in almost all proteins responsible for iron transport: DMT-1, TfR-1, L-CH, except TfR-2, and storage: FT-H/-L/-MT were reduced, with no changes in FPN. Moreover, 4-HNE expression (pg/mg; NFH 10.6 ± 8.4 vs. FH 55.7 ± 33.7; p < 0.0001) in FH was increased. HNE-4 significantly correlated with DMT-1 (r = -0.377, p = 0.036), L-CH (r = -0.571, p = 0.001), FT-H (r = -0.379, p = 0.036), also FPN (r = 0.422, p = 0.018). Reducing iron-gathering proteins and elevated oxidative stress in failing hearts is very unfavorable for myocardiocytes. It should be taken into consideration before treatment with drugs or supplements that elevate free oxygen radicals in the heart.

Current applications and outcomes of venoarterial extracorporeal membrane oxygenation based on 6 years of experience: risk factors for in­hospital mortality.

INTRODUCTION: Data regarding venoarterial extracorporeal membrane oxygenation (VA ECMO) as a temporary circulatory support in cardiogenic shock (CS) for Central Europe are scarce. OBJECTIVES: The aim of the study was to disclose indications, in-hospital, and long-term (1-year) mortality along with risk factors. PATIENTS AND METHODS: The study is a retrospective investigation of patients who underwent VA ECMO for CS at a cardiosurgical tertiary center, from January 2013 to June 2018. A broad spectrum of pre- and postimplantation factors was tested using univariable analysis. RESULTS: A total of 198 patients met the inclusion criteria. The median (interquartile range) duration of support was 207 (91­339) hours, with no significant disparity among hospital survivors and nonsurvivors (P = 0.09). A total of 40.4% of patients died during ECMO support, while the joined in-hospital and 6-month mortality progressed to 65.2%, and 1-year mortality to 67.2%; 9% underwent a subsequent heart transplantation. Main adverse events were bleeding (76%), infection (56%), neurologic injury (15%), and limb ischemia (15%). Multiorgan failure was the most decisive risk factor of in-hospital mortality (odds ratio, 4.45; P <⁠0.001). Patients with postcardiotomy CS had a significantly lower out-of-hospital survival rate than the nonsurgical group (32.3% vs 45%; log-rank P = 0.037). CONCLUSION: The study showed survival benefit, despite frequent complications. The protocol focusing on proper candidate selection and timing can positively impact patient survival. Additional risk reduction can be achieved with a further increase of the team experience with ECMO.

Prevalence and management of driveline infections in mechanical circulatory support - a single center analysis.

BACKGROUND: Driveline infections in continuous-flow left ventricular assist devices (cf-LVAD) remain the most common adverse event. This single-center retrospective study investigated the risk factors, prevalence and management of driveline infections. METHODS: Patients treated after cf-LVAD implantation from December 2014 to January 2020 were enrolled. Baseline data were collected and potential risk factors were elaborated. The multi-modal treatment was based on antibiotic therapy, daily wound care, surgical driveline reposition, and heart transplantation. Time of infection development, freedom of reinfection, freedom of heart transplantation, and death in the follow-up time were investigated. RESULTS: Of 75 observed patients, 26 (34.7%) developed a driveline infection. The mean time from implantation to infection diagnosis was 463 (±399; range, 35-1400) days. The most common pathogen was Staphylococcus aureus (n = 15, 60%). First-line therapy was based on antibiotics, with a primary success rate of 27%. The majority of patients (n = 19; 73.1%) were treated with surgical reposition after initial antibiotic therapy. During the follow-up time of 569 (±506; range 32-2093) days, the reinfection freedom after surgical transposition was 57.9%. Heart transplantation was performed in eight patients due to resistant infection. The overall mortality for driveline infection was 11.5%. CONCLUSIONS: Driveline infections are frequent in patients with implanted cf-LVAD, and treatment does not efficiently avoid reinfection, leading to moderate mortality rates. Only about a quarter of the infected patients were cured with antibiotics alone. Surgical driveline reposition is a reasonable treatment option and does not preclude subsequent heart transplantation due to limited reinfection freedom.

Literature-based considerations regarding organizing and performing cardiac surgery against the backdrop of the coronavirus pandemic.

BACKGROUND: The ongoing coronavirus disease 2019 (Covid-19) pandemic presents challenges for surgeons of all disciplines, including cardiologists. The volume of cardiac surgery cases has to comply with the mandatory constraints of healthcare capacities. The treatment of Covid-19-positive patients must also be considered. Unfortunately, no scientific evidence is available on this issue. Therefore, this study aimed to offer some consensus-based considerations, derived from available scientific papers, regarding the organization and performance of cardiac surgery against the backdrop of the Covid-19 pandemic. METHODS: Key recommendations were extracted from recent literature concerning cardiac surgery. RESULTSː Reducing elective cardiac procedures should be based on frequent clinical assessment of patients on the waiting list (every one or two weeks) and the current local status of the Covid-19 pandemic. Screening tests at admission for every patient are broadly recommended. Where appropriate, alternative treatment methods can be considered, including percutaneous techniques and minimally invasive surgery, if performed by experienced cardiac surgery teams. CONCLUSIONS: There is little evidence on the strategies to organize cardiac surgery in the Covid-19 pandemic. Most authors agree on reducing elective operations based on patients' clinical condition and the status of the Covid-19 pandemic. Admission screenings and the use of percutaneous or minimally invasive approaches should be preferred to reduce in-hospital stays.

The role of cardiac computed tomography in the diagnosis of prosthetic valve endocarditis - A comparison with transthoracic and transesophageal echocardiography and intra-operative findings.

BACKGROUND: Infective endocarditis is one of the most severe complications after prosthetic valve implantation and an accurate diagnosis is a clinical challenge. The purpose was to assess the diagnostic usefulness of cardiac computed tomography (CT) in valvular and perivalvular complications in patients with prosthetic valve endocarditis (PVE) and to compare CT results with transthoracic echocardiography (TTE), transesophageal echocardiography (TEE) and intraoperative findings. METHODS: The retrospective study included 44 consecutive patients with PVE who underwent cardiac surgery. The mean age was 59.6 ±â€¯12.9 years, 33 (75 %) were males. The presence of vegetations, abscess/pseudoaneurysm, paravalvular leakage (PVL) and inflammatory infiltration were evaluated by TTE, TEE and CT prior to surgery and the results were compared with intraoperative findings. RESULTS: Endocarditis affected 47 valves (26 mechanical, 21 biological) in 44 patients. PVE most often affected the aortic valve (n = 36), followed by the mitral valve (n = 9) and the pulmonary valve (n = 2). In the per-valve analysis, the sensitivity of TTE, TEE and CT in diagnosing vegetations was 65 %, 91 % and 96 %; abscess 44 %, 77 % and 89 %; paravalvular leakage 90 %, 100 % and 70 %; inflammatory infiltration 39 %, 56 % and 78 %, respectively. The combination of CT and echocardiography allowed the detection of abscesses/pseudoaneurysms and inflammatory infiltration in all cases except one. CONCLUSION: CT was superior to echocardiography in the diagnosis of paravalvular abscesses, vegetations and inflammatory infiltration. Echocardiography had a higher diagnostic value to CT in the evaluation of paravalvular leakage. Cardiac CT combined with echocardiography improves the diagnostic accuracy of PVE and both modalities should be performed.

Safety and performance of a novel transventricular beating heart mitral valve repair system: 1-year outcomes.

OBJECTIVES: The objective of this study was to evaluate the safety and performance of a novel, beating heart procedure that enables echocardiographic-guided beating heart implantation of expanded polytetrafluoroethylene (ePTFE) artificial cords on the posterior mitral leaflet of patients with degenerative mitral regurgitation. METHODS: Two prospective multicentre studies enrolled 13 (first-in-human) and 52 subjects, respectively. Patients were treated with the HARPOON beating heart mitral valve repair system. The primary (30-day) end point was successful implantation of cord(s) with mitral regurgitation reduction to ≤moderate. An independent core laboratory analysed echocardiograms. RESULTS: Of 65 patients enrolled, 62 (95%) achieved technical success, 2 patients required conversion to open surgery and 1 procedure was terminated. The primary end point was met in 59/65 (91%) patients. Among the 62 treated patients, the mean procedural time was 2.1 ± 0.5 h. Through discharge, there were no deaths, strokes or renal failure events. At 1 year, 2 of the 62 patients died (3%) and 8 (13%) others required reoperations. At 1 year, 98% of the patients with HARPOON cords were in New York Heart Association class I or II, and mitral regurgitation was none/trace in 52% (n = 27), mild in 23% (n = 12), moderate in 23% (n = 12) and severe in 2% (n = 1). Favourable cardiac remodelling outcomes at 1 year included decreased end-diastolic left ventricular volume (153 ± 41 to 119 ± 28 ml) and diameter (53 ± 5 to 47 ± 6 mm), and the mean transmitral gradient was 1.4 ± 0.7 mmHg. CONCLUSIONS: This initial clinical experience with the HARPOON beating heart mitral valve repair system demonstrates encouraging early safety and performance. CLINICAL REGISTRATION NUMBERS: NCT02432196 and NCT02768870.

Pulmonary artery aneurysm as a result of group 2 pulmonary artery hypertension in a patient with significant mitral and aortic valve disease - review and case report.

Aneurysms are uncommon, but potentially life-threatening abnormalities of the pulmonary arteries. Aneurysm of the main pulmonary artery (MPA) defined as MPA diameter over 40 mm was reported in 1 : 14 000 autopsies. The most frequent location is the main pulmonary artery (89% of cases), whereas the maximum described diameter is 106-170 mm. Clinical manifestations are usually nonspecific or asymptomatic. Right heart failure symptoms, pulmonary regurgitation, trachea or bronchi compression or pulmonary emboli caused by enlarged MPA are the most commonly described clinical manifestations. Pulmonary artery aneurysm dissection is an uncommon complication but associated with a high mortality rate. Unfortunately, guidelines regulating the optimal time for the surgical intervention still have not been developed. We present the history of 76-year-old patient suffering from an aneurysm of the pulmonary artery (74 × 61 mm), as well as mitral and aortic valve disease, who was successfully operated on in our hospital.