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.

The mean systemic pressure analog (Pmsa) calculated from running hemodynamic data, estimates mean systemic filling pressure (MSFP). This post hoc study used data from a porcine veno-arterial extra-corporeal membrane oxygenation (ECMO) model [n=9; Sus scrofa domesticus; ES breed (Schweizer Edelschwein)] with eight experimental conditions; Euvolemia [a volume state where ECMO flow produced normal mixed venous saturation (S_vO₂) without vascular collapse];three levels of increasing norepinephrine infusion (Vasoconstriction 1-3); status after stopping norepinephrine (Post Vasoconstriction); and three steps of volume expansion (10 mL/kg crystalloid bolus) (Volume Expansion 1-3). In each condition, Pmsa and a 'reduced-pump-speed-Pmsa' (Pmsa_red) were calculated from baseline and briefly reduced pump speeds, respectively. We calculated agreement for absolute values (per condition) and changes (between consecutive conditions) of Pmsa and Pmsa_red, against MSFP at zero ECMO-flow. Euvolemia venous return driving pressure was 5.1 ± 2.0 mmHg. Bland-Altman analysis for Pmsa vs. MSFP (all conditions; 72 data pairs) showed bias (confidence interval) 0.5 (0.1-0.9) mmHg; limits of agreement (LoA) -2.7-3.8 mmHg. Bias for ΔPmsa vs. ΔMSFP (63 data pairs): 0.2 (-0.2-0.6) mmHg, LoA -3.2-3.6 mmHg. Bias for Pmsa_red vs. MSFP (72 data pairs): 0.0 (-0.3-0.3) mmHg; LoA -2.3-2.4 mmHg. Bias for ΔPmsa_red vs. ΔMSFP (63 data pairs) was 0.2 (-0.1-0.4) mmHg; LoA -1.8-2.1 mmHg. In conclusion, during veno-arterial ECMO, under clinically relevant levels of vasoconstriction and volume expansion, Pmsa accurately estimated absolute and changing values of MSFP, with low between-method precision. The within-method precision of Pmsa was excellent, with a least significant change of 0.15 mmHg.

Bioprosthetic valve thrombosis has been considered uncommon, but recent studies have shown that it is more frequent than previously thought. Insufficient washout of the aortic sinus is believed to be a risk factor for bioprosthetic valve thrombosis. The objective of this in vitro experiment was to investigate the impact of aortic root morphology on blood flow in the aortic sinus and to relate these results to in vivo data obtained in patients with a transcatheter aortic valve implant. Two compliant aortic root phantoms with different morphologies (symmetrical and patient-specific) were fabricated with silicone. A bioprosthetic aortic valve was inserted in both phantoms. Haemodynamic measurements were performed in a pulsatile flow-loop replicating physiological flow and pressure conditions. The flow in the aortic root was visualized by injecting contrast agent (CA). The distribution of the CA was captured by a high-speed camera, and image post-processing was performed to quantify CA distribution in the aortic sinus. The results were compared with angiographic images after a transcatheter aortic valve implant. Blood flow in the aortic root and the washout of the sinus portion are significantly affected by aortic root morphology. CA arrives at the aortic sinus of the 2 phantoms at 0.09 s and 0.16 s after the valve opens in the symmetrical and the patient-specific phantoms, respectively. Delayed CA arrival was also observed in the patients with a transcatheter aortic valve implant. Aortic root morphology affects the blood flow in the aortic sinus and may be a factor in bioprosthetic valve thrombosis. Therefore, patient-specific aortic root morphology should be considered when selecting and positioning a prosthesis.

Clinical significance of aortopulmonary collaterals (APCs) in patients with univentricular heart remains controversial. This study aimed to evaluate the incidence and associated factors for APCs and their influence during staged palliation. In total, 430 patients who underwent staged palliation by bidirectional Glenn shunt and total cavopulmonary connection between 2003 and 2019 were examined. APCs were determined by angiogram. Incidence and interventions for APCs were analysed. The most frequent diagnosis was hypoplastic left heart syndrome in 146 (34%) patients. The median age at Glenn and Fontan was 4.9 months and 2.1 years, respectively. APCs were observed in 54 (13%) patients at Glenn and in 179 (42%) at Fontan. Closure of APCs was performed before Glenn in 12 (3%) patients, at Glenn in 13 (3%), after Glenn in 8 (2%), before Fontan in 44 (10%), at Fontan in 26 (6%) and after Fontan in 52 (12%). Hypoplastic left heart syndrome (P < 0.01) was highly associated with the development of APCs before Glenn. Lower Nakata-Index and younger age at Glenn shunt were associated with the development of APCs at Fontan procedure. The presence of APCs or intervention for APCs before total cavopulmonary connection did not influence intensive care unit stay or mortality after total cavopulmonary connection. APCs were most frequently observed before Fontan procedure. Hypoplastic left heart syndrome was highly associated with the development of APCs before Glenn shunt. Lower Nakata-Index and younger age at Glenn shunt were associated with APCs before Fontan procedure.

The coronavirus disease 2019 (COVID-19) pandemic has potentiated the need for implementation of strict safety measures in the medical care of surgical patients – and especially in cardiac surgery patients, who are at a higher risk of COVID-19-associated morbidity and mortality. Such measures not only require minimization of patients’ exposure to COVID-19 but also careful balancing of the risks of postponing nonemergent surgical procedures and providing appropriate and timely surgical care. We provide an overview of current evidence for preoperative strategies used in cardiac surgery patients, including risk stratification, telemedicine, logistical challenges during inpatient care, appropriate screening capacity, and decision-making on when to safely operate on COVID-19 patients. Further, we focus on perioperative measures such as safe operating room management and address the dilemma over when to perform cardiovascular surgical procedures in patients at risk.

This study was performed to determine the clinical and haemodynamic variables associated with early adverse outcomes after the neonatal Norwood procedure. Patients who underwent the neonatal Norwood procedure between 2001 and 2019 were included. The patient diagnosis, morphological characteristics and haemodynamic parameters were analysed to identify factors associated with length of stay (LOS) in the intensive care unit (ICU) and mortality during the stay. A total of 322 patients were depicted. The median age and weight at the Norwood procedure were 9 days and 3.2 kg, respectively. Certain morphological and preoperative parameters, such as birth weight below 2.5 kg, restrictive atrial septal defect, extracardiac anomalies and the diameter of the ascending aorta, were found to be associated with the LOS in the ICU. Analysis using early postoperative haemodynamic variables revealed that systolic arterial pressure, diastolic arterial pressure, serum lactate levels and reduced ventricular function at 2 days postoperatively were associated with the LOS in the ICU. Birth weight <2.5 kg (P = 0.010), a restrictive atrial septal defect (P = 0.001) and smaller ascending aorta (P = 0.039) were associated with death in the ICU. Reduced ventricular function, lower systolic aortic pressure and higher lactate levels at various time points (P < 0.05) were also associated with ICU deaths. The LOS in the ICU was significantly associated with late mortality (P < 0.001, Hazard Ratio (HR) = 1.015). The LOS in the ICU after the Norwood procedure was predicted by early postoperative haemodynamic variables, suggesting that good early postoperative haemodynamics determine early recovery. A prolonged stay in the ICU after the Norwood procedure was associated with late mortality.