Protocolo de pesquisa: implante de células-tronco em pacientes com cardiopatia isquêmica grave

Abstract

Heart failure (HF) affects approximately 2% of the world population. Ischemic cardiomyopathy accounts for two-thirds of cases of HF, which, when established, leads to physical limitations, multiple hospital admissions, declining quality of life, and increasing morbidity and mortality. Therapeutic alternatives range from pharmacological treatment to heart transplantation. Modern reperfusion strategies and advanced pharmacotherapeutic management have contributed to increase the survival of patients with ischemic cardiomyopathy, but none of these treatment strategies can reverse damage to cardiomyocytes or recover lost vasculature. Within this context, the concept of regenerative medicine, using stem cells (SC) for tissue repair, may become a reality. Mobilization and implantation of autologous, CD34+ hematopoietic SCs may improve myocardial function and perfusion. A total of 15 patients with severe ischemic cardiomyopathy, not eligible for other therapeutic alternatives, received autologous CD34+ cells collected from peripheral blood (PB) after G-CSF mobilization. SCs collected from PB were implanted in the myocardium using two routes (intracoronary and via the coronary sinus). All patients underwent clinical, laboratory, and imaging-based assessment to evaluate left ventricular function, perfusion and voltage. All patients were reevaluated after 4 months of post-implantation follow-up. Of the 15 initial patients, two died during follow-up (late post-implantation mortality). The different variables analyzed at 4-month follow-up showed improvement in functional classification (p=0.014), angina score (CCS) (p=0.006), the six-minute walk test (p=0.005), and quality of life (p=0.003). There was minor improvement in ejection fraction, as analyzed by echocardiography and magnetic resonance imaging, without reaching statistical significance (p=0.062 and p=0.0397 respectively); myocardial perfusion scintigraphy showed a non-significant improvement in viability (20.79% to 27.14%, p=0.390). Electroanatomic mapping of the left ventricle did not show any significant changes in electrical activity (p=0.767). CD34+ SC implantation into the myocardium using two routes simultaneously is a safe procedure. At 4-month follow-up, patients experienced improvement in symptoms and quality of life, but without significant improvement in left ventricular function, perfusion and voltage. Key words: Cell therapy, G-CSF, CD34+, ischemic cardiomyopathy