Purpose: to assess the prognostic role of myocardial fibrosis volume by gadolinium contrast-enhanced MRI in patients with HCM as a predictor of CHF progression to FC III NYHA, which required hospitalization.
Methods. The study included 124 patients with HCM (79 males and 45 females) aged 18 to 69 years (median age 46 years), median observation 42 months (3.5 years). The clinical end point included the progression of CHF symptoms from I – II FC to NYHA FC III, requiring hospitalization.
Results. Among 124 patients, the progression of CHF symptoms requiring hospitalization was observed in 24 people and occurred in the presence of preserved systolic function (LV EF> 50 %). 12 patients were hospitalized for two years, which indicates the rapid progression of symptoms of heart failure with NYHA FC I-II to FC III. The cumulative 3-year survival rate was 83 % (95% CI 76.5 - 90.1). The one-factor regression analysis was performed to determine the predictors of the progression of CHF symptoms and hospitalizations. As a new marker aimed at identifying patients at risk of adverse events, myocardial fibrosis volume was analyzed by MRI. Kaplan-Meier curve-free survival showed statistically significant differences in groups with a fibrosis volume of less than 20% and more than 20 % (log-rank p <0.001) and amounted to 95.2 % (95% CI 89.9 -100 %) and 32.1 % (95 % CI 17.9 -57.4 %), respectively. All indicators that were statistically significant in univariate regression analysis were included in the multivariate analysis and their threshold values were determined. In a multivariate analysis, independent factors associated with the progression of CHF and related hospitalization were the following characteristics: age> 50 years old (RR 5.9; 95 % CI 2.3–15.1, p <0.001), presence of episodes of AF (RR 5.6 ; 95% CI 2.2 - 14.2, p <0.001) and the volume of myocardial fibrosis by MRI = 20 % (RR 23.3; 95% CI 7.3 - 74.8, p <0.001). The regression analysis identified a group of patients with HCM, potentially having the risk of progression of CHF, which required hospitalization, with age> 50 years, episodes of AF and the amount of fibrosis = 20%.
Conclusion. Myocardial fibrosis index = 20% is associated with the development of adverse events associated with the progression of CHF in HCM and can be used to identify patients at high risk of developing CHF progression with an unfavorable outcome.