Caracterização e implicação clínica da mecânica do ventrículo direito na hipertensão pulmonar avaliada pela ressonância magnética cardíaca com o método de feature tracking

• Ano de defesa: 2016
• Autor(a) principal: Siqueira, Maria Eduarda Menezes de [UNIFESP]
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de São Paulo (UNIFESP)
• Palavras-chave em Português: Magnetic resonance imaging; Pulmonary hypertension; Strain; Right ventricle; Myocardial feature tracking; Ressonância magnética; Hipertensão pulmonar; Ventrículo direito; Feature-tracking miocárdico
• Link de acesso: https://sucupira.capes.gov.br/sucupira/public/consultas/coleta/trabalhoConclusao/viewTrabalhoConclusao.jsf?popup=true&id_trabalho=3682991; https://repositorio.unifesp.br/handle/11600/47222

Background: Prognosis in pulmonary hypertension (PH) is related to right ventricular (RV) function. An accurate and practical method to measure parameters like strain in myocardial tissue is of great clinical value, since it has been shown that strain is a more sensitive and earlier marker for contractile dysfunction than other frequently used parameter such as ejection fraction. Myocardial tissue tagging is the most available technique to measure strain by cardiac magnetic resonance (CMR); however, it is technical challenging and timeconsuming. Cardiovascular magnetic resonance myocardial feature-tracking (CMR-FT) is a novel technique that can rapidly perform strain analysis, because it can be employed with standard CMR cine-imaging without the need of additional acquisition. Objectives: To determine the feasibility, clinical and prognostic value of RV strain and strain rate analysis by CMR-FT in PH. Methods: We retrospectively enrolled 116 patients (age 52.2±12 years, 73.6% women) referred to CMR for PH evaluation who underwent right heart catheterization within 1 month. Using dedicated FT software, peak global longitudinal and circumferential RV strain and strain rate (GLS, GCS, GLSR, and GCSR, respectively) were quantified from standard cine images. Using multivariate regression analysis, we evaluated the associations of strain with a composite endpoint of death, lung transplantation, or functional class deterioration on long-term follow-up. Results: RV strain analysis was feasible in 110 (95%) patients. Patients were classified into: Group A (no PH, normal RVEF; n=17), Group B (PH, normal RVEF; n=26), or Group C (PH, abnormal RVEF; n= 67). All strain and strain rates values were reduced in Group C. Furthermore, GCSR was significantly reduced in Group B compared to Group A (-0.92 [-1.0 -(-0.7)]); p<0.001) versus (-1.12 [-1.3 - (-0.9)]); p<0.001). After adjustment for six clinically meaningful covariates, GLS (hazard ratio (HR) 1.06; CI 95% [1 a 1.12]; p=0.026), GLSR (HR 2.52; CI 95% [1.03 a 6.1]; p=0.04) and GCSR (HR 4.51; CI 95% [1.3 a 15.6]; p=0.01) were independently associated with the composite endpoint. GCSR successfully discriminated patients with and without events (HR 4.51; CI 95% [1.3 a 15.6]; p=0.01). Conclusion: Quantification of RV strain with CMR-FT is feasible in the majority of patients, correlates with disease severity and is independently associated with poor outcome in PH.