BACKGROUND:

Atrial fibrillation (AF) is a common arrhythmia in hypertrophic cardiomyopathy (HCM), frequently related to adverse outcomes. The AF-HCM point-score is a recently validated predictive model for the assessment of AF risk.

OBJECTIVES:

We sought to independently evaluate the novel AF-HCM score in a tertiary HCM center cohort in Brazil.

METHODS:

A longitudinal HCM cohort followed between 2007-2022 was retrospectively stratified for new onset AF, according to the presence of left atrial dimension (+2 points per 6mm increase), age at clinical evaluation (+3 points per 10-year increase), age at HCM diagnosis (-2 points per 10-year increase) and heart failure symptoms (+3 points if symptomatic). The AF-HCM score was classified as low (2,0%/year; score ≥22) for AF development. Cox regression model and Kaplan-Meier survival free from AF were analyzed, P< 0.001]. The intermediate and high-risk groups were associated with developing arrhythmia with a hazard ratio of 56.8 (95% CI 3.4-944.6), P=0.005. The specificity and the negative predictive value were 100%. On the contrary of the previous North-America study population, most patients of the Brazilian cohort were in the high-risk category (37% vs. 52%).

CONCLUSION:

The AF-HCM score is a reasonable tool for recognizing patients not prone to develop AF among those stratified as low risk in a Brazilian cohort. However, the model was limited to identify intermediate and high risk individuals in contrast to the previously stratified North-American population.