L'objectif principal de ce travail est d’étudier en profondeur certaines techniques biostatistiques avancées en recherche évaluative en chirurgie cardiaque adulte. Les études ont été conçues pour intégrer les concepts d'analyse de survie, analyse de régression avec “propensity score”, et analyse de coûts. Le premier manuscrit évalue la survie après la réparation chirurgicale de la dissection aigüe de l’aorte ascendante. Les analyses statistiques utilisées comprennent : analyses de survie avec régression paramétrique des phases de risque et d'autres méthodes paramétriques (exponentielle, Weibull), semi-paramétriques (Cox) ou non-paramétriques (Kaplan-Meier) ; survie comparée à une cohorte appariée pour l’âge, le sexe et la race utilisant des tables de statistiques de survie gouvernementales ; modèles de régression avec “bootstrapping” et “multinomial logit model”. L'étude a démontrée que la survie s'est améliorée sur 25 ans en lien avec des changements dans les techniques chirurgicales et d’imagerie diagnostique. Le second manuscrit est axé sur les résultats des pontages coronariens isolés chez des patients ayant des antécédents d'intervention coronarienne percutanée. Les analyses statistiques utilisées comprennent : modèles de régression avec “propensity score” ; algorithme complexe d'appariement (1:3) ; analyses statistiques appropriées pour les groupes appariés (différences standardisées, “generalized estimating equations”, modèle de Cox stratifié). L'étude a démontrée que l’intervention coronarienne percutanée subie 14 jours ou plus avant la chirurgie de pontages coronariens n'est pas associée à des résultats négatifs à court ou long terme. Le troisième manuscrit évalue les conséquences financières et les changements démographiques survenant pour un centre hospitalier universitaire suite à la mise en place d'un programme de chirurgie cardiaque satellite. Les analyses statistiques utilisées comprennent : modèles de régression multivariée “two-way” ANOVA (logistique, linéaire ou ordinale) ; “propensity score” ; analyses de coûts avec modèles paramétriques Log-Normal. Des modèles d’analyse de « survie » ont également été explorés, utilisant les «coûts» au lieu du « temps » comme variable dépendante, et ont menés à des conclusions similaires. L'étude a démontrée que, après la mise en place du programme satellite, moins de patients de faible complexité étaient référés de la région du programme satellite au centre hospitalier universitaire, avec une augmentation de la charge de travail infirmier et des coûts. / The main objective of this work is to study in depth advanced biostatistical techniques in adult cardiac surgery outcome research. The studies were designed to incorporate the concepts of survival analysis, regression analysis with propensity score, and cost analysis. The first manuscript assessed survival, and cardiovascular specific mortality, following surgical repair of acute ascending aortic dissection. The statistical analyses included survival analyses with multiphase parametric hazard regression and other parametric (exponential, Weibull), semi-parametric (Cox) or non-parametric models (Kaplan Meier), comparison with the survival of a matched cohort for age, gender and race using State lifetables, and modelization with bootstrapping and multinomial logit models. The study showed that the early and late survival following surgical repair has improved progressively over 25 years in association with noticeable changes in surgical techniques and preoperative diagnostic testing. The second manuscript focused on outcomes following isolated coronary artery bypass grafting in patients with a history of percutaneous coronary intervention. The statistical analyses included multivariable regression models with propensity score, complex matching algorithm (1:3) and appropriate statistical analyses for matched groups (standardized differences, generalized estimating equations, and survival analyses with stratified proportional hazards models). The study showed that remote prior percutaneous coronary intervention more than 14 days before coronary artery bypass grafting surgery was not associated with adverse outcomes at short or long-term follow-up. The third manuscript evaluated the financial consequences and the changes in case mix that occurred at an academic medical center subsequent to the implementation of a satellite cardiac surgery program. The statistical analyses included two-way ANOVA multivariable regression models (logistic, linear or ordinal), propensity score, and cost analyses using Log-Normal parametric models. “Survival” analyses models were also explored, using “cost” instead of “time” as the outcome of interest, and led to similar conclusions. The study showed that, after implementation of the satellite cardiac surgery program, fewer patients of lower complexity came to the academic medical center from the satellite program area, with a significant increase in nursing workload and costs.

La cardiomyopathie ischémique et l’insuffisance cardiaque (IC) sont deux des principales causes de morbidité et de mortalité dans les pays industrialisés. L’IC représente la condition finale résultant de plusieurs pathologies affectant le myocarde. Au Canada, plus de 400 000 personnes souffrent d’IC. Malgré la grande variété de traitements disponibles pour prendre en charge ces patients à haut risque de mortalité, l’évolution et le pronostic clinique de cette population demeurent sombres. Les thérapies de régénération par transplantation cellulaire représentent de nouvelles approches pour traiter les patients souffrant d’IC. L’impact de cette approche cellulaire et les mécanismes qui sous-tendent l’application de ce nouveau mode de traitement demeurent obscurs. Les hypothèses proposées dans cette thèse sont les suivantes : 1) l’évolution à long terme des patients qui se présentent en IC grave est nettement défavorable malgré les techniques actuelles de revascularisation chirurgicale à cœur battant; 2) la thérapie cellulaire et, plus spécifiquement, l’injection intracoronaire précoce de milieu de culture cellulaire, permet d’améliorer la récupération fonctionnelle du ventricule gauche suite à un infarctus aigu du myocarde; et 3) la mobilisation de l’axe cœur-moelle osseuse constitue un mécanisme de réponse important lors de la survenue d’un événement ischémique chronique affectant le myocarde. / Congestive heart failure (CHF) remains a leading cause of mortality in the developed world. There are more than 400,000 diagnosed cases of this pathology in Canada. Despite the numerous treatment options available for patients presenting with left ventricular dysfunction, the evolution of this population is still dismal. Stem cell transplantation is a potential approach to repopulate the injured myocardium, to treat heart failure, and to restore cardiac function. However, the exact mechanisms underlying the beneficial effects of this approach remain to be elucidated. The hypotheses of this thesis are the following: 1) the long-term evolution of patients undergoing coronary artery bypass graft surgery is still poor, even when considering the use of new innovative surgical strategies such as off-pump coronary revascularization; 2) the intracoronary injection of concentrated biologically active factors secreted by stem cells can achieve early protection of the ischemic myocardium and preserve heart function; and 3) the bone marrow/heart interaction in a critical axis is involved in chronic myocardial repair following persistent ischemic injury.

INTRODUÇÃO: A utilização de enxertos arteriais na revascularização cirúrgica do miocárdio já está bem estabelecida atualmente pelos cirurgiões cardiovasculares, e sua esqueletização tem apresentado algumas vantagens, a princípio com a artéria torácica interna esquerda. OBJETIVO: Com o objetivo de analisar esse método de dissecção na artéria radial, foram avaliados os desempenhos funcional e hemodinâmico bem como as características morfoanatômicas e histológicas dos enxertos aortocoronários de artéria radial, esqueletizados ou com tecidos adjacentes, na revascularização cirúrgica do miocárdio. MÉTODOS: Foram comparados 40 pacientes, distribuídos randomicamente em dois grupos. No grupo I foi utilizada artéria radial esqueletizada (20 pacientes) e no grupo II, artéria radial com tecidos adjacentes (20 pacientes), para os ramos marginais da artéria coronária esquerda. No total, 39 pacientes foram submetidos a cinecoronariografia e fluxometria com cateter-guia Doppler de 12 MHz (0,014 polegada, Flowire, Jometrics Inc.), no pós-operatório imediato. RESULTADOS: Os dois grupos apresentaram características demográficas semelhantes. As variáveis intra-operatórias principais da artéria radial também foram semelhantes, com comprimento de 17,1 cm no grupo I e de 16,3 cm no grupo II, e débito livre de 80,3 ml/min no grupo I e de 95,5 ml/min no grupo II. Não foram observadas diferenças morfoanatômicas e histológicas nos grupos comparados. Os diâmetros dos enxertos de artéria radial, calculados por meio de angiografia quantitativa no pós-operatório, foram semelhantes (2,66 mm no grupo I e 2,53 mm no grupo II), assim como as variáveis fluxométricas (fluxo sanguíneo de 54,9 ml/min no grupo I e de 44,28 ml/min no grupo II, e reserva de fluxo de 2,12 no grupo I e de 2 no grupo II). Por outro lado, a cinecoronariografia revelou presença de oclusão em um enxerto e estenose em cinco enxertos no grupo II, enquanto o grupo I apresentou estenose em apenas um enxerto de artéria radial (p = 0,091). CONCLUSÕES: Os enxertos aortocoronários de artéria radial tiveram bom desempenho funcional e hemodinâmico precoce. Não houve diferença entre os grupos quanto ao desempenho funcional e hemodinâmico precoce, e quanto às características morfoanatômicas e histológicas. / BACKGROUND: The use of artery grafts in the surgical revascularization of the myocardium is currently a well-established procedure by cardiovascular surgeons, and its skeletonization has posed some advantages, in principle, with the left internal thoracic artery. OBJECTIVE: With the purpose of analyzing this radial artery harvest method, the study evaluated the functional and hemodynamic early performance, as well as the morphological anatomic and histological features of the aortic coronary grafts of the radial artery, skeletonized or with surrounding tissues, in the surgical revascularization of the myocardium. METHODS: The study compared 40 patients, randomly distributed in two groups. In Group I, we employed a skeletonized radial artery (20 patients), and in Group II, the radial artery with surrounding tissues (20 patients), for the marginal branches of the left coronary artery. In total, 39 patients underwent cinecoronariography and fluxometry with a 12-MHz Doppler guide catheter (0.014 in., Flowire, Jometrics Inc.), in the immediate postoperative period. RESULTS: Both groups presented similar demographic features. The main intra-surgical variables of the radial artery were also similar, with an extension of 17.1 cm in Group I, and 16.3 cm in Group II, and the free flow was of 80.3 ml/min in Group I, and of 95.5 ml/min in Group II. No morphological anatomic and histological differences were observed in the compared groups. The diameters of the radial artery grafts, which were calculated by quantitative angiography in the postoperative period, were similar (2.66 mm in Group I, and 2.53 mm in Group II), as well as the flow variables (blood flow of 54.9 ml/min in Group I, and of 44.28 ml/min in Group II, and a flow reserve of 2.12 in Group I, and of 2 in Group II). On the other hand, the cinecoronariography revealed the presence of an occlusion in one graft, and of stenosis in five grafts of Group II, while Group I presented stenosis in only one radial artery graft (p = 0.091). CONCLUSIONS: The aortic coronary grafts of the radial artery displayed good functional and hemodynamic early performance. There was no difference between the groups regarding functional and hemodynamic early performance, and the morphological anatomical and histological features.

Dans la dysfonction endothéliale, le compartiment endothélial circulant joue simultanément le rôle d’acteur impliqué dans la régénération du tissu lésé et celui d’indicateur de l’état d’altération ou de régénération de l’endothélium. Dans l’artérite oblitérante des membres inférieurs (AOMI), l’un des axes de recherche porte sur le développement d’un produit de thérapie cellulaire capable d’induire la formation de néo-Vaisseaux. Face à la difficulté d’obtenir et d`amplifier des cellules progénitrices endothéliales (CPE) chez l’adulte sain, et a fortiori chez le patient, l’une des hypothèses laisse envisager le recours à d’autres types cellulaires ayant des propriétés vasculogéniques. Chez patients atteints de maladies cardiovasculaires, et d’AOMI en particulier, les cellules mononuclées de moelle osseuse et les CPE montrent des propriétés angiogéniques diminuées. Nous avons mis en évidence la capacité des cellules souches mésenchymateuses (CSM) isolées de patients atteints d’AOMI à induire une reperfusion, par recrutement de cellules endothéliales in situ, avec la même efficacité que celles de donneurs sains. Les CSM ne se différencient pas en cellules endothéliales mais agissent par paracrinie. La seconde hypothèse d’obtention d’un produit de thérapie cellulaire autologue angiogène est de trier des cellules plus immatures que les CPE afin de les différencier secondairement vers la lignée endothéliale à l’image du modèle pathologique de la cellule souche d’hémangiome CD133+ qui laisse envisager les Very Small Embryonic Like stem cells (VSEL), cellules souches multipotentes CD133+, comme un candidat de cellules post-Natales à potentiel vasculaire. Nous avons dérivés, en culture en conditions angiogéniques, des VSEL qui acquièrent un phénotype mésenchymateux mais présentent un profil sécrétoire proche de celui des CPE. Les VSEL favorisent la revascularisation post-Ischémique et acquièrent un phénotype endothélial in vitro et in vivo suggérant que les VSEL peuvent être à l’origine de la lignée endothéliale. Les VSEL se présentent également comme un biomarqueur de la dysfonction endothéliale mobilisé de la moelle osseuse (MO) vers le sang périphérique (PB) chez les patients souffrant d’AOMI. Les biomarqueurs cellulaires circulants représentent non seulement des marqueurs non invasifs de l’endothélium mais peuvent également apporter des informations utiles pour le diagnostic, le pronostic et le suivi thérapeutique des patients souffrant de pathologies associées à une dysfonction endothéliale. Une modification du nombre de CPE et de cellules endothéliales circulantes (CEC) dans la circulation a été rapportée dans différentes situations pathologiques respectivement associées à une régénération et une altération endothéliale telle l’augmentation du taux de CEC chez des patients présentant une hypertension artérielle pulmonaire (HTAP). La technique de référence pour le dénombrement des CEC dans le sang périphérique est l’immunoséparation magnétique (IMS). Cette méthode non automatisée et chronophage, repose sur l’énumération par microscopie à fluorescence des cellules CD146+ préalablement isolées. Bien que reproductible, cette numération est soumise à de nombreux biais de quantification, difficile à mettre en oeuvre et sujette à interprétation. La mise au point d’une méthode de détection automatisée des CEC par cytométrie à focalisation acoustique (AFC) s’est montrée fiable et robuste, dans une cohorte de patients atteints d’HTAP traitée ou non, constituant une alternative pertinente à l’analyse par microscopie. L’ensemble de ces travaux ouvre donc de nouvelles perspectives dans la détection des biomarqueurs cellulaires circulants impliqués dans la dysfonction endothéliale, proposant les VSEL comme nouvel acteur vasculogénique. / In endothelial dysfunction, circulating endothelial compartment simultaneously plays the role of actor involved in the regeneration of injured tissue and reflects endothelium state. In peripheral arterial disease (PAD), one of the research areas is the development of a cellular therapy product capable of inducing the formation of neo-Vessels. Faced with the difficulty to obtain and amplify endothelial progenitor cells (EPC) in adults, one of the assumptions lets consider the use of other cell types with vasculogenic properties. In patients with cardiovascular disease, and PAD in particular, bone marrow mononuclear cells and EPC show reduced angiogenic properties. We have demonstrated the ability of isolated mesenchymal stem cells (MSCs) from PAD patients to induce reperfusion by recruitment of endothelial cells in situ, with the same efficiency as that of healthy donors MSCs. MSCs do not differentiate into endothelial cells but act by paracrine. The second hypothesis of obtaining an autologous angiogenic cell therapy product is to sort cells more immature than the CPE and to differentiate them secondarily into endothelial lineage as the pathological cell model of hemangioma stem cells CD133 + which lets consider the Very Small Embryonic like stem cells (VSEL), CD133 + multipotent stem cells as a potential candidate of postnatal vascular cell. We have derived and cultured in angiogenic conditions VSEL that acquired a mesenchymal phenotype but exhibited a secretory profile similar to that of EPC. VSEL promote post-Ischemic revascularization and acquire an endothelial phenotype in vitro and in vivo suggesting that VSEL may be responsible for the endothelial lineage. VSEL also appear as a biomarker of endothelial dysfunction mobilized from bone marrow (BM) to peripheral blood (PB) in patients with PAD. Cellular circulating biomarkers are not only non-Invasive markers of endothelium but can also provide useful information for the diagnosis, prognosis and therapeutic monitoring of patients with endothelial dysfunction associated pathologies. Changing the number of EPC and circulating endothelial cells (CEC) in the circulation has been reported in different pathological situations respectively associated with endothelial regeneration and alteration such as the increase of CEC in patients with pulmonary arterial hypertension (PAH). The reference technique for the enumeration of CEC in peripheral blood is magnetic immunoseparation (IMS). This non-Automated and time-Consuming method, based on the enumeration by fluorescence microscopy of CD146 + cells isolated. Although reproducible, this count is subject to many through quantification, difficult to implement and subject to interpretation. The development of an acoustic focusing cytometry (AFC) method for automated detection of CEC has proved reliable and robust results, in a cohort of patients with PAH treated or not, constituting a relevant alternative analysis to microscopy. All of this work opens new perspectives in the detection of cellular circulating biomarkers involved in endothelial dysfunction, suggesting VSEL as new vasculogenic actor.

No description available.

<p>Ishemijska bolest srca najče&scaron;će nastaje kao posledica razvoja aterosklerotskih promena na koronarnim krvnim sudovima koji dovode do suženja lumena i posledičnog pada protoka arterijske krvi u području vaskularizacije. Akutni oblik koronarne bolesti koji zahteva hitnu primenu reperfuzione terapije je ST elevirani infarkt miokarda. EKG ima veliki značaj u postavljanju dijagnoze ali i u proceni uspe&scaron;nosti same reperfuzije. &Scaron;irina QRS kompleksa jedan je od EKG parametara čija dinamika promena može ukazati na uspe&scaron;nost pPKI i veličinu infarktne zone. Evaluacija &scaron;irine QRS kompleksa kao prediktora veličine infarkta miokarda i reperfuzije nakon pPKI kod pacijenata sa STEMI. Ispitivanje je sprovedeno kao prospektivna, opservaciona klinička studija na Klinici za kardiologiju, Instituta za kardiovaskularne bolesti Vojvodine u periodu od januara 2016. do decembra 2018. godine. U isptivanje je uključeno 200 pacijenata sa STEMI kod kojih je urađena pPKI. Na osnovu dužine trajanja tegoba formirane su dve grupe od po 100 pacijenata. Grupa A kod kojih je totalno ishemijsko vreme bilo &lt;6h i grupa B kod kojih je totalno ishemijsko vreme između 6 i 12h. . Sprovedeno je EKG praćenje radi procene &scaron;irine QRS kompleksa intrahospitalno (pre procedure, odmah nakon pPKI kao i posle 1h i 72h) i na dve vizite ambulantno tokom &scaron;estomesečnog praćenja (nakon mesec dana i &scaron;est meseci). Ehokardiografija je urađena kod svih pacijenata intrahospitalno i na &scaron;estomesečnom ambulantnom pregledu. &Scaron;irine QRS kompleksa su korelirane sa rezultatima interventne procedure procenjene TIMI protokom i TMPG, dinamikom kardiospecifičnih enzima i ehokardiografskim nalazima. U istraživanje je uključeno 71% mu&scaron;karaca i 29% žena, prosečna starost uzorka iznosila je 60.6&plusmn;11.39. Dužina trajanja tegoba značajno se razlikovala između grupa. U grupi A tegobe su trajale prosečno 120 minuta (90-180), dok su u grupi B trajale 420 minuta (360-600) (p&lt;0.0005). DTB nije se značajno razlikovao, 42 minuta (31-54.5) u odnosu na 40.5 minuta (34.5-55) (p=0.818). Prosečna &scaron;irina QRS kompeksa na EKG-u pre pPKI nije se značajno razlikovala između grupa, 100 msec (90-110) u odnosu na 100 msec (93-110) (p=0.308). Nakon reperfuzije uočena je značajna razlika u &scaron;irini QRS kompleksa između grupa na svim intrahospitalnim kao i EKG-ima načinjenim tokom perioda praćenja. QRS kompleks je &scaron;iri kod pacijenata iz grupe B (p&lt;0.0005). Pacijenti iz grupe A koji su imali prohodnu infarktnu arteriju sa TIMI 3 protokom pre implantacije stenta imali su značajno uži QRS kompleks na incijilanom EKG-u u odnosu na pacijente kod kojih je IRA bila sub/okludirana sa TIMI protokom &le;2 (p=0.001). U grupi B prohodna infarktna arterija sa TIMI 3 protokom nije značajno uticala na &scaron;irinu QRS kompleksa na inicijalnom EKG-u (p=0.144). Na EKG-ima nakon procedure QRS kompleks bio je značajno &scaron;iri kod pacijenata kod kojih je TIMI protok &le;2, ali samo za grupu pacijenata koja se javila unutar 6h od početka tegoba (p=0.001). QRS kompleks kod pacijenata koji su se javili nakon 6h od početka tegoba jeste bio uži, ali bez statistički značajne razlike (p=0.336). Pearsonovim testom registrovano je postojanje negativne korelacije &scaron;irine QRS kompleksa i istisne frakcije leve komore, ali i pozitivne korelacije sa WMSI i indeksiranim end sistolnim i end dijastolnim volumenom. ROC analizom pokazano je da ukoliko je QRS kompleks &scaron;iri od 89 msec nakon mesec dana, 8.5 puta je veći rizik od snižene EF na &scaron;estomesečnoj kontroli (p&lt;0.0005, AUC=0.808, cut-off=89msec.). ROC analiza pokazala je i da ukoliko je QRS kompleks &scaron;iri od 99msec 1h nakon procedure, 5 puta je veći rizik od pojave MACE (p&lt;0.0005, AUC=0.744, cut-off=99msec). Izvedena su dva matematička modela zasnovana na &scaron;irini QRS kompleksa koja vr&scaron;e predikciju snižene EF i pojave MACE tokom perioda praćenja. &Scaron;irina QRS kompleksa je pokazatelj reperfuzije kod pacijenata sa STEMI kod kojih se načini revaskularizacija unutar 6h od nastanka tegoba. &Scaron;irina QRS kompleksa mesec dana nakon STEMI predstavlja nezavisni prediktor snižene EF. Pro&scaron;irenje preko 89msec 8.5 povećava rizik od snižene EF. &Scaron;irina QRS kompleksa jedan sat nakon pPKI predstavlja nezavisni prediktor za MACE. Pro&scaron;irenje preko 99msec 5 puta povećava rizik od neželjenog kardiolo&scaron;kog događaja. Izvedena su dva matematička modela koja koriste &scaron;irinu QRS kompleksa i sa visokom precizno&scaron;ću vr&scaron;e predikciju MACE-a, odnosno snižene EF nakon &scaron;est meseci.&nbsp;</p> / <p>Ischemic heart disease most commonly occurs as a result of the atherosclerotic changes in the coronary vessels that lead to the narrowing of the lumen and consequent fall in arterial blood flow in the vascularization area. An acute form of coronary artery disease requiring immediate reperfusion therapy is ST-elevation myocardial infarction. The ECG is of great importance not only in making the diagnosis but also in evaluating the success of the reperfusion itself. The duration of the QRS complex is one of the ECG parameters whose change in dynamics can indicate the success of pPCI as well as the size of the infarct zone. Evaluation of the width of the QRS complex as a predictor of myocardial infarction size and reperfusion after pPCI in patients with STEMI. The study was conducted as a prospective, observational clinical study at the Cardiology Clinic of the Institute of Cardiovascular Diseases of Vojvodina between January 2016 and December 2018. The study included 200 patients with STEMI in whom pPCI was performed. Based on the length of discomforts two groups with 100 patients were formed. Group A had a total ischemic time &lt;6h and the total ischemic time in group B was between 6-12h. To assess the duration of the QRS complex, the ECG monitoring was performed intrahospital (before the procedure, immediately after pPCI as well as 1h and 72h after the procedure) and on two outpatient visits during the six-month follow-up period (after one month and six months). Echocardiography was performed in all patients intrahospital and at a six-month outpatient visit. The duration of the QRS complex correlated with the results of the interventional procedure that was evaluated by the TIMI flow and TMPG, the dynamics of cardiospecific enzymes and echocardiography findings. The survey included 71% of men and 29% of women with an average age of 60.6 &plusmn; 11.39. The duration of the discomforts varied significantly between the groups. In group A the discomforts lasted 120 minutes in an average (90-180), while they lasted 420 minutes in group B (360-600) (p &lt;0.0005). DTB did not differ significantly, 42 minutes (31-54.5) versus 40.5 minutes (34.5-55) (p = 0.818). The average duration of the QRS complex on the ECG before pPCI did not differ significantly between the groups, 100 msec (90-110) versus 100 msec (93-110) (p = 0.308). After the reperfusion, a significant difference in the duration of the QRS complex was observed between the groups at all intrahospital ECGs and the ECGs performed during the follow-up period. The QRS complex was broader in group B patients (p &lt;0.0005). Group A patients who had a patent infarct artery with TIMI 3 flow before the stent implantation had a significantly narrower QRS complex on the initial ECG compared to the patients whose IRA was sub / occluded with TIMI flow &le;2 (p = 0.001). In group B, the patent infarct artery with TIMI 3 flow did not significantly affect the duration of the QRS complex at the initial ECG. (p = 0.144). At the post-procedural ECGs the QRS complex was significantly broader in patients with TIMI flow &le;2, but only in the group of patients who arrived within 6 h from the onset of discomforts (p = 0.001). The QRS complex in patients who arrived 6 h after the onset of discomforts was narrower but without statistically significant difference (p = 0.336). The Pearson test registered the existence of a negative correlation of the QRS complex width and the left ventricular ejection fraction, but also a positive correlation with the WMSI and index end-systolic and end-diastolic volumes. The ROC analysis showed that if the QRS complex was wider than 89 msec after one month, there was an 8.5 times higher risk of decreased EF at the six-month control examination (p &lt;0.0005, AUC = 0.808, cut-off = 89msec.). The ROC analysis also showed that if the QRS complex was wider than 99msec 1h after the procedure, there was a 5 times higher risk of MACE (p &lt;0.0005, AUC = 0.744, cut-off = 99msec). Two mathematical models based on the width of the QRS complex were derived that predicted the lowered EF and the occurrence of MACE during the monitored period. The width of the QRS complex is an indicator of reperfusion in patients with STEMI who undergo revascularization within 6 hours from the onset of discomforts. The width of the QRS complex one month after STEMI is an independent predictor of decreased EF. Broadening over 89msec increases the risk of lowered EF for 8.5 times. The width of the QRS complex one hour after pPCI represents an independent predictor of MACE. Broadening over 99msec increases the risk of an adverse cardiac event 5 times. Two mathematical models have derived that use the width of the QRS complex and predict MACE with high precision as well as reduced EF after six months.</p>