Covalently Labeled Fluorescent Exosomes for In Vitro and In Vivo Applications.

The vertiginous increase in the use of extracellular vesicles and especially exosomes for therapeutic applications highlights the necessity of advanced techniques for gaining a deeper knowledge of their pharmacological properties. Herein, we report a novel chemical approach for the robust attachment of commercial fluorescent dyes to the exosome surface with covalent binding. The applicability of the methodology was tested on milk and cancer cell-derived exosomes (from U87 and B16F10 cancer cells). We demonstrated that fluorescent labeling did not modify the original physicochemical properties of exosomes. We tested this nanoprobe in cell cultures and healthy mice to validate its use for in vitro and in vivo applications. We confirmed that these fluorescently labeled exosomes could be successfully visualized with optical imaging.This study was supported by the Comunidad de Madrid, projects: “Y2018/NMT-4949 (NanoLiver-CM)” and “S2017/BMD-3867 (RENIM-CM)”; it was also co-funded by the European Structural and Investment Fund. The CNIC is supported by the Instituto de Salud Carlos III (ISCIII), the Ministerio de Ciencia e Innovación (MCIN), and the Pro CNIC Foundation, and it is a Severo Ochoa Center of Excellence (SEV-2015-0505). JV was supported by grants from Instituto de Salud Carlos III (PI18/01833), co-funded by European Regional Development Fund (ERDF) and from Comunidad de Madrid, project “S2017/BMD2737 (ExoHep-CM)”, co-funded by European Structural and Investment Fund. A. Santos-Coquillat is grateful for the financial support from Ministerio de Ciencia e Innovación, Instituto de Salud Carlos III Sara Borrell Fellowship grant CD19/00136.S

Pathophysiology Underlying the Bimodal Edema Phenomenon After Myocardial Ischemia/Reperfusion.

BACKGROUND Post-ischemia/reperfusion (I/R) myocardial edema was recently shown to follow a consistent bimodal pattern: an initial wave of edema appears on reperfusion and dissipates at 24 h, followed by a deferred wave that initiates days after infarction, peaking at 1 week. OBJECTIVES This study examined the pathophysiology underlying this post-I/R bimodal edematous reaction. METHODS Forty instrumented pigs were assigned to different myocardial infarction protocols. Edematous reaction was evaluated by water content quantification, serial cardiac magnetic resonance T2-mapping, and histology/immunohistochemistry. The association of reperfusion with the initial wave of edema was evaluated in pigs undergoing 40-min/80-min I/R and compared with pigs undergoing 120-min ischemia with no reperfusion. The role of tissue healing in the deferred wave of edema was evaluated by comparing pigs undergoing standard 40-min/7-day I/R with animals subjected to infarction without reperfusion (chronic 7-day coronary occlusion) or receiving post-I/R high-dose steroid therapy. RESULTS Characterization of post-I/R tissue changes revealed maximal interstitial edema early on reperfusion in the ischemic myocardium, with maximal content of neutrophils, macrophages, and collagen at 24 h, day 4, and day 7 post-I/R, respectively. Reperfused pigs had significantly higher myocardial water content at 120 min and T2 relaxation times on 120 min cardiac magnetic resonance than nonreperfused animals. Permanent coronary occlusion or high-dose steroid therapy significantly reduced myocardial water content on day 7 post-infarction. The dynamics of T2 relaxation times during the first post-infarction week were altered significantly in nonreperfused pigs compared with pigs undergoing regular I/R. CONCLUSIONS The 2 waves of the post-I/R edematous reaction are related to different pathophysiological phenomena. Although the first wave is secondary to reperfusion, the second wave occurs mainly because of tissue healing processes.S

R2 prime (R2') magnetic resonance imaging for post-myocardial infarction intramyocardial haemorrhage quantification.

To assess whether R2* is more accurate than T2* for the detection of intramyocardial haemorrhage (IMH) and to evaluate whether T2' (or R2') is less affected by oedema than T2* (R2*), and thus more suitable for the accurate identification of post-myocardial infarction (MI) IMH. Reperfused anterior MI was performed in 20 pigs, which were sacrificed at 120 min, 24 h, 4 days, and 7 days. At each time point, cardiac magnetic resonance (CMR) T2- and T2*-mapping scans were recorded, and myocardial tissue samples were collected to quantify IMH and myocardial water content. After normalization by the number of red blood cells in remote tissue, histological IMH increased 5.2-fold, 10.7-fold, and 4.1-fold at Days 1, 4, and 7, respectively. The presence of IMH was correlated more strongly with R2* (r = 0.69; P = 0.013) than with T2* (r = -0.50; P = 0.085). The correlation with IMH was even stronger for R2' (r = 0.72; P = 0.008). For myocardial oedema, the correlation was stronger for R2* (r = -0.63; P = 0.029) than for R2' (r = -0.50; P = 0.100). Multivariate linear regressions confirmed that R2* values were significantly explained by both IMH and oedema, whereas R2' values were mostly explained by histological IMH (P = 0.024) and were little influenced by myocardial oedema (P = 0.262). Using CMR mapping with histological validation in a pig model of reperfused MI, R2'more accurately detected IMH and was less influenced by oedema than R2* (and T2*). Further studies are needed to elucidate whether R2' is also better suited for the characterization of post-MI IMH in the clinical setting.This study was partially supported by a competitive grant from the Carlos III Institute of Health-Fondo de Investigacion Sanitaria and the European Regional Development Fund (ERDF/FEDER) (PI16/02110), the Spanish Ministry of Science, Innovation and Universities (MICIU), ERDF/FEDER SAF2013-49663-EXP, by the Comunidad de Madrid (S2017/BMD-3867 RENIM-CM) and cofunded with European structural and investment funds. This study forms part of a Master Research Agreement between the CNIC and Philips Healthcare. This research program is part of an institutional agreement between FIIS Fundacion Jimenez Diaz and the CNIC. The CNIC is supported by the Ministry of Science, Innovation and Universities MICIU the Instituto de Salud Carlos III (ISCiii), and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (award SEV-2015-0505). X.R. has received support from the DYSEC-CNIC CARDIOJOVEN fellowship program. R.F.-J. is a recipient of funding from the European Union Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie (Agreement No. 707642).S

Energy substrate metabolism, mitochondrial structure and oxidative stress after cardiac ischemia-reperfusion in mice lacking UCP3.

Myocardial ischemia-reperfusion (IR) injury may result in cardiomyocyte dysfunction. Mitochondria play a critical role in cardiomyocyte recovery after IR injury. The mitochondrial uncoupling protein 3 (UCP3) has been proposed to reduce mitochondrial reactive oxygen species (ROS) production and to facilitate fatty acid oxidation. As both mechanisms might be protective following IR injury, we investigated functional, mitochondrial structural, and metabolic cardiac remodeling in wild-type mice and in mice lacking UCP3 (UCP3-KO) after IR. Results showed that infarct size in isolated perfused hearts subjected to IR ex vivo was larger in adult and old UCP3-KO mice than in equivalent wild-type mice, and was accompanied by higher levels of creatine kinase in the effluent and by more pronounced mitochondrial structural changes. The greater myocardial damage in UCP3-KO hearts was confirmed in vivo after coronary artery occlusion followed by reperfusion. S1QEL, a suppressor of superoxide generation from site IQ in complex I, limited infarct size in UCP3-KO hearts, pointing to exacerbated superoxide production as a possible cause of the damage. Metabolomics analysis of isolated perfused hearts confirmed the reported accumulation of succinate, xanthine and hypoxanthine during ischemia, and a shift to anaerobic glucose utilization, which all recovered upon reoxygenation. The metabolic response to ischemia and IR was similar in UCP3-KO and wild-type hearts, being lipid and energy metabolism the most affected pathways. Fatty acid oxidation and complex I (but not complex II) activity were equally impaired after IR. Overall, our results indicate that UCP3 deficiency promotes enhanced superoxide generation and mitochondrial structural changes that increase the vulnerability of the myocardium to IR injury.We are grateful to F. S´ anchez-Madrid, B. Iba´nez ˜ and E. Lara for facilitating experiments at CNIC (Madrid, Spain) and to W.E. Louch for facilitating experiments at the University of Oslo (Oslo, Norway). We thank B. Littlejohns, I. Khaliulin and H. Lin from M.S. Suleiman’s group (University of Bristol, Bristol, UK) for their valuable help with Langendorff perfusion experiments. We also thank E.T. Chouchani from M.P. Murphy’s group (Cambridge, UK) for help with metabolomics analysis, M. Guerra of the Electron Microscopy Unit at CBMSO (Madrid, Spain) for processing the samples for electron microscopy analysis, and A.V. Alonso (CNIC) for echocardiography analyses. The work in our laboratory is funded the Instituto de Salud Carlos III (FIS PI19/01030) to SC. Institutional grants from the Fundacion ´ Ramon ´ Areces and Banco de Santander to the CBMSO are also acknowledged.S

Remote ischemic preconditioning ameliorates anthracycline-induced cardiotoxicity and preserves mitochondrial integrity

Aims: Anthracycline-induced cardiotoxicity (AIC) is a serious adverse effect among cancer patients. A central mechanism of AIC is irreversible mitochondrial damage. Despite major efforts, there are currently no effective therapies able to prevent AIC. Methods and results: Forty Large-White pigs were included. In Study 1, 20 pigs were randomized 1:1 to remote ischaemic preconditioning (RIPC, 3 cycles of 5 min leg ischaemia followed by 5 min reperfusion) or no pretreatment. RIPC was performed immediately before each intracoronary doxorubicin injections (0.45 mg/kg) given at Weeks 0, 2, 4, 6, and 8. A group of 10 pigs with no exposure to doxorubicin served as healthy controls. Pigs underwent serial cardiac magnetic resonance (CMR) exams at baseline and at Weeks 6, 8, 12, and 16, being sacrifice after that. In Study 2, 10 new pigs received 3 doxorubicin injections (with/out preceding RIPC) and were sacrificed at week 6. In Study 1, left ventricular ejection fraction (LVEF) depression was blunted animals receiving RIPC before doxorubicin (RIPC-Doxo), which had a significantly higher LVEF at Week 16 than doxorubicin treated pigs that received no pretreatment (Untreated-Doxo) (41.5 ± 9.1% vs. 32.5 ± 8.7%, P = 0.04). It was mainly due to conserved regional contractile function. In Study 2, transmission electron microscopy (TEM) at Week 6 showed fragmented mitochondria with severe morphological abnormalities in Untreated-Doxo pigs, together with upregulation of fission and autophagy proteins. At the end of the 16-week Study 1 protocol, TEM revealed overt mitochondrial fragmentation with structural fragmentation in Untreated-Doxo pigs, whereas interstitial fibrosis was less severe in RIPC+Doxo pigs. Conclusion: In a translatable large-animal model of AIC, RIPC applied immediately before each doxorubicin injection resulted in preserved cardiac contractility with significantly higher long-term LVEF and less cardiac fibrosis. RIPC prevented mitochondrial fragmentation and dysregulated autophagy from AIC early stages. RIPC is a promising intervention for testing in clinical trials in AIC.Fil: Galán Arriola, Carlos. Centro de Investigacion Biomedica En Red.; EspañaFil: Villena Gutiérrez, Rocio. Centro de Investigacion Biomedica En Red.; EspañaFil: Higuero Verdejo, María I.. Centro Nacional de Investigaciones Cardiovasculares; EspañaFil: Díaz Rengifo, Iván A.. Centro Nacional de Investigaciones Cardiovasculares; EspañaFil: Pizarro, Gonzalo. Centro de Investigacion Biomedica En Red.; EspañaFil: López, Gonzalo J.. Centro Nacional de Investigaciones Cardiovasculares; EspañaFil: de Molina Iracheta, Antonio. Centro Nacional de Investigaciones Cardiovasculares; EspañaFil: Pérez Martínez, Claudia. Universidad de Leon. Facultad de Veterinaria; ArgentinaFil: García, Rodrigo Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Medicina y Biología Experimental de Cuyo; ArgentinaFil: González Calle, David. Centro de Investigacion Biomedica En Red.; EspañaFil: Lobo, Manuel. Centro de Investigacion Biomedica En Red.; EspañaFil: Sánchez, Pedro L.. Centro de Investigacion Biomedica En Red.; EspañaFil: Oliver, Eduardo. Centro de Investigacion Biomedica En Red.; EspañaFil: Córdoba, Raúl. Hospital Fundacion Jimenez Diaz; EspañaFil: Fuster, Valentin. Centro Nacional de Investigaciones Cardiovasculares; EspañaFil: Sánchez González, Javier. No especifíca;Fil: Ibanez, Borja. Centro de Investigacion Biomedica En Red.; Españ

Generation and characterization of a novel knockin minipig model of Hutchinson-Gilford progeria syndrome

Hutchinson-Gilford progeria syndrome (HGPS) is an extremely rare genetic disorder for which no cure exists. The disease is characterized by premature aging and inevitable death in adolescence due to cardiovascular complications. Most HGPS patients carry a heterozygous de novo LMNA c.1824C > T mutation, which provokes the expression of a dominant-negative mutant protein called progerin. Therapies proven effective in HGPS-like mouse models have yielded only modest benefit in HGPS clinical trials. To overcome the gap between HGPS mouse models and patients, we have generated by CRISPR-Cas9 gene editing the first large animal model for HGPS, a knockin heterozygous LMNA c.1824C > T Yucatan minipig. Like HGPS patients, HGPS minipigs endogenously co-express progerin and normal lamin A/C, and exhibit severe growth retardation, lipodystrophy, skin and bone alterations, cardiovascular disease, and die around puberty. Remarkably, the HGPS minipigs recapitulate critical cardiovascular alterations seen in patients, such as left ventricular diastolic dysfunction, altered cardiac electrical activity, and loss of vascular smooth muscle cells. Our analysis also revealed reduced myocardial perfusion due to microvascular damage and myocardial interstitial fibrosis, previously undescribed readouts potentially useful for monitoring disease progression in patients. The HGPS minipigs provide an appropriate preclinical model in which to test human-size interventional devices and optimize candidate therapies before advancing to clinical trials, thus accelerating the development of effective applications for HGPS patients.This project was mainly supported by an Established Investigator Award from the Progeria Research Foundation (2014-52), and from the Spanish Ministerio de Ciencia, Innovación y Universidades (MCIU), and the European Regional Development Fund (FEDER, “A way to build Europe”) (SAF2016-79490-R, CB16/11/00405). Ana Barettino has a predoctoral contract from MCIU (BES-2017-079705). Work at Universidad de Murcia is supported by Fundación Seneca-Agencia de Ciencia y Tecnología de la Región de Murcia (20040/GERM/16). The CNIC is supported by the MCIU and the Pro-CNIC Foundation and is a Severo Ochoa Center of Excellence (SEV-2015-0505).S

Myocardial Edema After Ischemia/Reperfusion Is Not Stable and Follows a Bimodal Pattern Imaging and Histological Tissue Characterization

Background: It is widely accepted that edema occurs early in the ischemic zone and persists in stable form for at least 1 week after myocardial ischemia/reperfusion. However, there are no longitudinal studies covering from very early (minutes) to late (1 week) reperfusion stages confirming this phenomenon. Objectives: This study sought to perform a comprehensive longitudinal imaging and histological characterization of the edematous reaction after experimental myocardial ischemia/reperfusion. Methods: The study population consisted of 25 instrumented Large-White pigs (30 kg to 40 kg). Closed-chest 40-min ischemia/reperfusion was performed in 20 pigs, which were sacrificed at 120 min (n = 5), 24 h (n = 5), 4 days (n = 5), and 7 days (n = 5) after reperfusion and processed for histological quantification of myocardial water content. Cardiac magnetic resonance (CMR) scans with T2-weighted short-tau inversion recovery and T2-mapping sequences were performed at every follow-up stage until sacrifice. Five additional pigs sacrificed after baseline CMR served as controls. Results: In all pigs, reperfusion was associated with a significant increase in T2 relaxation times in the ischemic region. On 24-h CMR, ischemic myocardium T2 times returned to normal values (similar to those seen pre-infarction). Thereafter, ischemic myocardium-T2 times in CMR performed on days 4 and 7 after reperfusion progressively and systematically increased. On day 7 CMR, T2 relaxation times were as high as those observed at reperfusion. Myocardial water content analysis in the ischemic region showed a parallel bimodal pattern: 2 high water content peaks at reperfusion and at day 7, and a significant decrease at 24 h. Conclusions: Contrary to the accepted view, myocardial edema during the first week after ischemia/reperfusion follows a bimodal pattern. The initial wave appears abruptly upon reperfusion and dissipates at 24 h. Conversely, the deferred wave of edema appears progressively days after ischemia/reperfusion and is maximal around day 7 after reperfusion

Serial Magnetic Resonance Imaging to Identify Early Stages of Anthracycline-Induced Cardiotoxicity

BACKGROUND: Anthracycline-induced cardiotoxicity is a major clinical problem, and early cardiotoxicity markers are needed. OBJECTIVES: The purpose of this study was to identify early doxorubicin-induced cardiotoxicity by serial multiparametric cardiac magnetic resonance (CMR) and its pathological correlates in a large animal model. METHODS: Twenty pigs were included. Of these, 5 received 5 biweekly intracoronary doxorubicin doses (0.45 mg/kg/injection) and were followed until sacrifice at 16 weeks. Another 5 pigs received 3 biweekly doxorubicin doses and were followed to 16 weeks. A third group was sacrificed after the third dose. All groups underwent weekly CMR examinations including anatomical and T2 and T1 mapping (including extracellular volume [ECV] quantification). A control group was sacrificed after the initial CMR. RESULTS: The earliest doxorubicin-cardiotoxicity CMR parameter was T2 relaxation-time prolongation at week 6 (2 weeks after the third dose). T1 mapping, ECV, and left ventricular (LV) motion were unaffected. At this early time point, isolated T2 prolongation correlated with intracardiomyocyte edema secondary to vacuolization without extracellular space expansion. Subsequent development of T1 mapping and ECV abnormalities coincided with LV motion defects: LV ejection fraction declined from week 10 (2 weeks after the fifth and final doxorubicin dose). Stopping doxorubicin therapy upon detection of T2 prolongation halted progression to LV motion deterioration and resolved intracardiomyocyte vacuolization, demonstrating that early T2 prolongation occurs at a reversible disease stage. CONCLUSIONS: T2 mapping during treatment identifies intracardiomyocyte edema generation as the earliest marker of anthracycline-induced cardiotoxicity, in the absence of T1 mapping, ECV, or LV motion defects. The occurrence of these changes at a reversible disease stage shows the clinical potential of this CMR marker for tailored anthracycline therapy.This study was partially supported by grants from the Ministerio de Ciencia, Innovacion y Universidades through the Carlos III Institute of Health-Fondo de Investigacion Sanitaria (P116/02110), the European Regional Development Fund (SAF2013-49663-EXP), and the Spanish Society of Cardiology (FEC basic science in cardiology grant). This research program is part of an institutional agreement between the CNIC and FIIS-Fundacion Jimenez Diaz. This study forms part of a Master Research Agreement between the CNIC and Philips Healthcare, and is part of a bilateral research program between Hospital de Salamanca Cardiology Department and the CNIC. The CNIC is supported by the Ministerio de Ciencia, Innovacion y Universidades, and the Pro-CNIC Foundation, and is a Severo Ochoa Center of Excellence (MEIC award SEV-2015-0505). Drs. Galan-Arriola and Villena-Gutierrez are P-FIS fellows (Instituto de Salud Carlos III). Dr. Fernandez-Jimenez has received funding through the European Union Horizon 2020 Research and Innovation program under grant MSCA-IF-GF-707642. Dr. Sanchez -Gonzalez is an employee of Philips Healthcare. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.S

Remote ischaemic preconditioning ameliorates anthracycline-induced cardiotoxicity and preserves mitochondrial integrity.

Anthracycline-induced cardiotoxicity (AIC) is a serious adverse effect among cancer patients. A central mechanism of AIC is irreversible mitochondrial damage. Despite major efforts, there are currently no effective therapies able to prevent AIC. Forty Large-White pigs were included. In Study 1, 20 pigs were randomized 1:1 to remote ischaemic preconditioning (RIPC, 3 cycles of 5 min leg ischaemia followed by 5 min reperfusion) or no pretreatment. RIPC was performed immediately before each intracoronary doxorubicin injections (0.45 mg/kg) given at Weeks 0, 2, 4, 6, and 8. A group of 10 pigs with no exposure to doxorubicin served as healthy controls. Pigs underwent serial cardiac magnetic resonance (CMR) exams at baseline and at Weeks 6, 8, 12, and 16, being sacrifice after that. In Study 2, 10 new pigs received 3 doxorubicin injections (with/out preceding RIPC) and were sacrificed at week 6. In Study 1, left ventricular ejection fraction (LVEF) depression was blunted animals receiving RIPC before doxorubicin (RIPC-Doxo), which had a significantly higher LVEF at Week 16 than doxorubicin treated pigs that received no pretreatment (Untreated-Doxo) (41.5 ± 9.1% vs. 32.5 ± 8.7%, P = 0.04). It was mainly due to conserved regional contractile function. In Study 2, transmission electron microscopy (TEM) at Week 6 showed fragmented mitochondria with severe morphological abnormalities in Untreated-Doxo pigs, together with upregulation of fission and autophagy proteins. At the end of the 16-week Study 1 protocol, TEM revealed overt mitochondrial fragmentation with structural fragmentation in Untreated-Doxo pigs, whereas interstitial fibrosis was less severe in RIPC+Doxo pigs. In a translatable large-animal model of AIC, RIPC applied immediately before each doxorubicin injection resulted in preserved cardiac contractility with significantly higher long-term LVEF and less cardiac fibrosis. RIPC prevented mitochondrial fragmentation and dysregulated autophagy from AIC early stages. RIPC is a promising intervention for testing in clinical trials in AIC.This study is part of a project that has received funding from the European Research Council (ERC) under the European Union Horizon 2020 Research and Innovation Programme (ERCConsolidator Grant agreement No. 819775 to B.I). The study was also partially funded by an ERA-CVD Joint Translational Call 2016 (funded through the Instituto de Salud Carlos III (ISCIII) and the European Regional Development Fund (ERDF), # AC16/00021) and by a Health Research Project from the ISCIII-FIS (# PI16/02110). Carlos Galán-Arriola and Rocío Villena-Gutiérrez are P-FIS fellows (Instituto de Salud Carlos III). This study forms part of a research agreement between the CNIC and Philips Healthcare. The CNIC is supported by the ISCIII, the Ministerio de Ciencia e Innovación, and the Pro-CNIC Foundation and is a Severo Ochoa Center of Excellence (MEIC award SEV-2015-0505).S

Atrial Infarction and Ischemic Mitral Regurgitation Contribute to Post-MI Remodeling of the Left Atrium

BACKGROUND: Left atrial (LA) remodeling after an acute myocardial infarction (MI) is poorly characterized regarding its determinants or its effect on ischemic mitral regurgitation (MR) development. OBJECTIVES: The purpose of this study was: 1) to compare LA structural remodeling in experimental MI swine models recapitulating the effects of left ventricular (LV) dysfunction, ischemic MR, and left atrial infarction (LAI); and 2) to analyze how LA remodeling influences ischemic MR development. METHODS: Three models of MI were generated: 1) proximal left circumflex (LCx) coronary artery occlusion involving the LA branch (LAI group); 2) proximal LCx occlusion not involving the LA branch (LCx group); and 3) left anterior descending (LAD) occlusion (LAD group). Serial cardiac magnetic resonance scans were performed to define LA and LV remodeling and ischemic MR, and were correlated with histology. RESULTS: Occlusion of the LA branch (LAI group) induced a greater degree of LA dilation at 1 and 8 weeks post-MI than the LCx and LAD groups, along with early and severe impairment of LA function. In the LCx and LAD groups, LA dysfunction was less pronounced and not consistent. Development of ischemic MR was more pronounced in the LAI group than in the LCx group. Histology confirmed atrial infarction with extensive fibrosis in the LAI group and interstitial fibrosis in the LCx group. In the LAD group, LA remodeling was not observed by cardiac magnetic resonance or histology. CONCLUSIONS: We provide the first experimental evidence of the deleterious effect of acute LAI on atrial structural remodeling, characterized by early LA dilation, dysfunction, and fibrosis, and early occurrence of ischemic MR.This study was supported by a competitive grant from the Carlos III Institute of Health-Fondo de Investigacion Sanitaria and the European Regional Development Fund (ERDF/FEDER) (PI13/01979 and PI16/02110); the Spanish Ministry of Economy, Industry, and Competitiveness (MEIC) and ERDF/FEDER (SAF2013-49663-EXP); and, in part, by the FP7-PEOPLE-2013-ITN Next Generation Training in Cardiovascular Research and Innovation (CARDIONEXT). This research program is part of an institutional agreement between FIIIS-Fundación Jiménez Díaz and the Centro Nacional de Investigaciones Cardiovasculares Carlos III (CNIC). This study forms part of a Master Research Agreement between the CNIC and Philips Healthcare. The CNIC is supported by the MEIC and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (MEIC award SEV-2015-0505). The Cardiology Department at Leiden University Medical Center has received unrestricted research grants from Medtronic, Biotronik, Boston Scientific, Edwards Lifesciences, and General Electric Healthcare. Dr. Aguero is an FP7-PEOPLE-2013-ITN-Cardionext fellow. Dr. Fernández-Jiménez holds an FICNIC fellowship from the Fundació Jesús Serra, the Fundación Interhospitalaria de Investigación Cardiovascular (FIC), and CNIC. Dr. Sanchez-Gonzalez is an employee of Philips Healthcare. Dr. Delgado has received speaker fees from Abbott Vascular.S