Relationship between bioimpedance vector displacement and renal function after a marathon in non-elite runners

Peer ReviewedPostprint (published version

Noninvasive assessment of an engineered bioactive graft in myocardial infarction: impact on cardiac function and scar healing

Cardiac tissue engineering, which combines cells and biomaterials, is promising for limiting the sequelae of myocardial infarction (MI). We assessed myocardial function and scar evolution after implanting an engineered bioactive impedance graft (EBIG) in a swine MI model. The EBIG comprises a scaffold of decellularized human pericardium, green fluorescent protein-labeled porcine adipose tissue-derived progenitor cells (pATPCs), and a customized-design electrical impedance spectroscopy (EIS) monitoring system. Cardiac function was evaluated noninvasively by using magnetic resonance imaging (MRI). Scar healing was evaluated by using the EIS system within the implanted graft. Additionally, infarct size, fibrosis, and inflammation were explored by histopathology. Upon sacrifice 1 month after the intervention, MRI detected a significant improvement in left ventricular ejection fraction (7.5%64.9% vs. 1.4%63.7%; p = .038) and stroke volume (11.565.9 ml vs. 364.5 ml; p = .019) in EBIG-treated animals. Noninvasive EIS data analysis showed differences in both impedance magnitude ratio (20.02 6 0.04 per day vs. 20.48 6 0.07 per day; p = .002) and phase angle slope (20.18°60.24° per day vs.23.52°60.84° per day; p = .004) in EBIG compared with control animals. Moreover, in EBIG-treated animals, the infarct size was 48% smaller (3.4%60.6% vs. 6.5%61%; p = .015), less inflammation was found by means of CD25+ lymphocytes (0.65 6 0.12 vs. 1.26 6 0.2; p = .006), and a lower collagen I/III ratio was detected (0.4960.06 vs. 1.6660.5; p = .019). An EBIG composed of acellular pericardium refilled with pATPCs significantly reduced infarct size and improved cardiac function in a preclinical model of MI. Noninvasive EIS monitoring was useful for tracking differential scar healing in EBIG-treated animals, which was confirmed by less inflammation and altered collagen deposit.Peer ReviewedPostprint (published version

Electrical stimulation of cardiac adipose tissue-derived progenitor cells modulates cell phenotype and genetic machinery

A major challenge of cardiac tissue engineering is directing cells to establish the physiological structure and function of the myocardium being replaced. Our aim was to examine the effect of electrical stimulation on the cardiodifferentiation potential of cardiac adipose tissue-derived progenitor cells (cardiac ATDPCs). Three different electrical stimulation protocols were tested; the selected protocol consisted of 2ms monophasic square-wave pulses of 50mV/cm at 1Hz over 14days. Cardiac and subcutaneous ATDPCs were grown on biocompatible patterned surfaces. Cardiomyogenic differentiation was examined by real-time PCR and immunocytofluorescence. In cardiac ATDPCs, MEF2A and GATA-4 were significantly upregulated at day 14 after stimulation, while subcutaneous ATDPCs only exhibited increased Cx43 expression. In response to electrical stimulation, cardiac ATDPCs elongated, and both cardiac and subcutaneous ATDPCs became aligned following the linear surface pattern of the construct. Cardiac ATDPC length increased by 11.3%, while subcutaneous ATDPC length diminished by 11.2% (p=0.013 and p=0.030 vs unstimulated controls, respectively). Compared to controls, electrostimulated cells became aligned better to the patterned surfaces when the pattern was perpendicular to the electric field (89.71±28.47o for cardiac ATDPCs and 92.15±15.21o for subcutaneous ATDPCs). Electrical stimulation of cardiac ATDPCs caused changes in cell phenotype and genetic machinery, making them more suitable for cardiac regeneration approaches. Thus, it seems advisable to use electrical cell training before delivery as a cell suspension or within engineered tissue.Peer ReviewedPreprin

Effect of COMBinAtion therapy with remote ischemic conditioning and exenatide on the Myocardial Infarct size: a two-by-two factorial randomized trial (COMBAT-MI)

Remote ischemic conditioning (RIC) and the GLP-1 analog exenatide activate different cardioprotective pathways and may have additive effects on infarct size (IS). Here, we aimed to assess the efficacy of RIC as compared with sham procedure, and of exenatide, as compared with placebo, and the interaction between both, to reduce IS in humans. We designed a two-by-two factorial, randomized controlled, blinded, multicenter, clinical trial. Patients with ST-segment elevation myocardial infarction receiving primary percutaneous coronary intervention (PPCI) within 6 h of symptoms were randomized to RIC or sham procedure and exenatide or matching placebo. The primary outcome was IS measured by late gadolinium enhancement in cardiac magnetic resonance performed 3–7 days after PPCI. The secondary outcomes were myocardial salvage index, transmurality index, left ventricular ejection fraction and relative microvascular obstruction volume. A total of 378 patients were randomly allocated, and after applying exclusion criteria, 222 patients were available for analysis. There were no significant interactions between the two randomization factors on the primary or secondary outcomes. IS was similar between groups for the RIC (24 ± 11.8% in the RIC group vs 23.7 ± 10.9% in the sham group, P = 0.827) and the exenatide hypotheses (25.1 ± 11.5% in the exenatide group vs 22.5 ± 10.9% in the placebo group, P = 0.092). There were no effects with either RIC or exenatide on the secondary outcomes. Unexpected adverse events or side effects of RIC and exenatide were not observed. In conclusion, neither RIC nor exenatide, or its combination, were able to reduce IS in STEMI patients when administered as an adjunct to PPCI

Sudden cardiac death

La mort sobtada representa un problema clínic per resoldre que succeeix amb molta freqüència. En un elevat percentatge de casos, l'origen es cardíac. La mort sobtada d'origen cardíac es la conseqüència final de múltiplesmecanismes fisiopatològics possibles, que promouen un substrat arritmogènic de manera aguda o crònica. El desenvolupament d'un o múltiples factors desencadenants pot interactuar amb el substrat arritmogènic i facilitar l'arítmia final amb característiques letals. A pesar de que l'estratificació de risc de les poblacions es factible, la prevenció delsmecanismes desencadenants i promotors de malalties es la mesura més necessària i correcta. El tractament amb el cardioversor-desfibril.lador implantable (ICD) és el més segur per la gran majoria de persones en les que s'ha pogut interrompre la mort sobtada cardíaca. Només en un petit subgrup de pacients molt seleccionats, la teràpia amb fàrmacs, l'ablació transcateter, la cirurgia antitaquicàrdica o el trasplantament de cor poden ésser considerades com el tractament electiu. La decisió del millor tractament per cada pacient cal considerar-la de forma individualitzada, tenint en compte les seves característiques, el tipus d'arítmia que ha sofert el pacient i la pròpia experiència de cada hospital en un tècnica determinada.Sudden death is a frequent event whose causes may not be anticipated, but often has a cardiac origin. Sudden cardiac death is the final consequence of many pathophysiological mechanisms which have caused acute or chronic arrhythmogenic disease. Single or multifactorial triggering factors may interact with the arrhythmogenic substrate to lead to lethal arrhythmias. Stratifying populations according to risk is feasible, but the immediate priority is prevention of triggering and disease-promoting factors. ICD therapy is the best treatment for most survivors of sudden cardiac death. Drug therapy, catheter ablation, antitachycardia surgery or heart transplant are only first-choice treatments for very few patients. Choosing the best therapy is an individual decision based on the patient's clinical picture, the type of arrhythmia seen and hospital experience in the various technique

Soluble Neprilysin and Corin Concentrations in Relation to Clinical Outcome in Chronic Heart Failure

OBJECTIVES: This study investigated whether patients with chronic heart failure (HF) can be stratified according to the combination of soluble neprilysin and corin concentrations and whether this is related to clinical outcome. BACKGROUND: Natriuretic peptide processing by the enzymes corin and neprilysin plays a pivotal role in conversion of pro-natriuretic peptides to active natriuretic peptides, as well as their degradation, respectively. METHODS: A prospective cohort of patients with chronic HF (n = 1,009) was stratified into 4 equal groups based on high or low neprilysin/corin concentration relative to the median: 1) low neprilysin/low corin; 2) low neprilysin/high corin; 3) high neprilysin/low corin; and 4) high neprilysin/high corin. Cox regression survival analysis was performed for the composite primary endpoint of cardiovascular death and HF hospitalization. RESULTS: Median neprilysin and corin concentrations were not correlated (rho: -0.04; p = 0.21). Although in univariate analysis there was no association with outcome, after correction for baseline differences in age and sex, a significant association with survival was demonstrated: with highest survival in group 1 (low neprilysin/low corin) and lowest in group 4 (high neprilysin/high corin) (adjusted hazard ratio: 1.56; p = 0.003), which remained statistically significant after comprehensive multivariable analysis (adjusted hazard ratio: 1.41; p = 0.03). CONCLUSIONS: Stratification of patients with chronic HF based on circulating neprilysin and corin concentrations is associated with clinical outcomes. These results suggest that regulation of these enzymes is of importance in chronic HF and may offer an interesting approach for classification of patients with HF in a step toward individualized HF patient management

Electrical stimulation of cardiac adipose tissue-derived progenitor cells modulates cell phenotype and genetic machinery

A major challenge of cardiac tissue engineering is directing cells to establish the physiological structure and function of the myocardium being replaced. Our aim was to examine the effect of electrical stimulation on the cardiodifferentiation potential of cardiac adipose tissue-derived progenitor cells (cardiac ATDPCs). Three different electrical stimulation protocols were tested; the selected protocol consisted of 2ms monophasic square-wave pulses of 50mV/cm at 1Hz over 14days. Cardiac and subcutaneous ATDPCs were grown on biocompatible patterned surfaces. Cardiomyogenic differentiation was examined by real-time PCR and immunocytofluorescence. In cardiac ATDPCs, MEF2A and GATA-4 were significantly upregulated at day 14 after stimulation, while subcutaneous ATDPCs only exhibited increased Cx43 expression. In response to electrical stimulation, cardiac ATDPCs elongated, and both cardiac and subcutaneous ATDPCs became aligned following the linear surface pattern of the construct. Cardiac ATDPC length increased by 11.3%, while subcutaneous ATDPC length diminished by 11.2% (p=0.013 and p=0.030 vs unstimulated controls, respectively). Compared to controls, electrostimulated cells became aligned better to the patterned surfaces when the pattern was perpendicular to the electric field (89.71±28.47o for cardiac ATDPCs and 92.15±15.21o for subcutaneous ATDPCs). Electrical stimulation of cardiac ATDPCs caused changes in cell phenotype and genetic machinery, making them more suitable for cardiac regeneration approaches. Thus, it seems advisable to use electrical cell training before delivery as a cell suspension or within engineered tissue.Peer Reviewe

Electromechanical conditioning of adult progenitor cells improves recovery of cardiac function after myocardial infarction

Cardiac cells are subjected to mechanical and electrical forces, which regulate gene expression and cellular function. Therefore, in vitro electromechanical stimuli could benefit further integration of therapeutic cells into the myocardium. Our goals were (a) to study the viability of a tissue engineered construct with cardiac adipose tissue-derived progenitor cells (cardiac ATDPCs) and (b) to examine the effect of electromechanically stimulated cardiac ATDPCs within a myocardial infarction (MI) model inmice for the first time. Cardiac ATDPCs were electromechanically stimulated at 2-millisecond pulses of 50 mV/cm at 1 Hz and 10% stretching during 7 days. The cells were harvested, labeled, embedded in a fibrin hydrogel, and implanted over the infarcted area of the murine heart. A total of 39 animals were randomly distributed and sacrificed at 21 days: groups of grafts without cells and with stimulated or nonstimulated cells. Echocardiography and gene and protein analyses were also carried out. Physiologically stimulated ATDPCs showed increased expression of cardiac transcription factors, structural genes, and calcium handling genes. At 21 days after implantation, cardiac function (measured as left ventricle ejection fraction between presacrifice and post-MI) increased up to 12% in stimulated grafts relative to nontreated animals. Vascularization and integration with the host blood supply of grafts with stimulated cells resulted in increased vessel density in the infarct border region. Trained cells within the implanted fibrin patch expressed main cardiac markers and migrated into the underlying ischemic myocardium. To conclude, synchronous electromechanical cell conditioning before delivery may be a preferred alternative when considering strategies for heart repair after myocardial infarction.Peer ReviewedPostprint (author's final draft

Electromechanical conditioning of adult progenitor cells improves recovery of cardiac function after myocardial infarction

Cardiac cells are subjected to mechanical and electrical forces, which regulate gene expression and cellular function. Therefore, in vitro electromechanical stimuli could benefit further integration of therapeutic cells into the myocardium. Our goals were (a) to study the viability of a tissue engineered construct with cardiac adipose tissue-derived progenitor cells (cardiac ATDPCs) and (b) to examine the effect of electromechanically stimulated cardiac ATDPCs within a myocardial infarction (MI) model inmice for the first time. Cardiac ATDPCs were electromechanically stimulated at 2-millisecond pulses of 50 mV/cm at 1 Hz and 10% stretching during 7 days. The cells were harvested, labeled, embedded in a fibrin hydrogel, and implanted over the infarcted area of the murine heart. A total of 39 animals were randomly distributed and sacrificed at 21 days: groups of grafts without cells and with stimulated or nonstimulated cells. Echocardiography and gene and protein analyses were also carried out. Physiologically stimulated ATDPCs showed increased expression of cardiac transcription factors, structural genes, and calcium handling genes. At 21 days after implantation, cardiac function (measured as left ventricle ejection fraction between presacrifice and post-MI) increased up to 12% in stimulated grafts relative to nontreated animals. Vascularization and integration with the host blood supply of grafts with stimulated cells resulted in increased vessel density in the infarct border region. Trained cells within the implanted fibrin patch expressed main cardiac markers and migrated into the underlying ischemic myocardium. To conclude, synchronous electromechanical cell conditioning before delivery may be a preferred alternative when considering strategies for heart repair after myocardial infarction.Peer Reviewe