To the Editor:

We read with interest the study by Essayagh and colleagues¹ in the current edition of the journal. The authors hypothesize the potential prognostic value of mitral annular disjunction (MAD) in the occurrence of advanced degenerative mitral valve (MV) pathology and early failure of surgical mitral repair. Using echocardiographic evaluation in 61 patients undergoing surgery for isolated degenerative MV prolapse, Essayagh et al. compare the frequencies of various echo-derived markers and postoperative events, stratified by the presence or absence of MAD (MAD+/–). The authors conclude that any statistically significant differences in the occurrence of select variables/characteristics from the MAD + group are likely caused by the presence of MAD. We disagree with this inference of causality as it ignores the probability that the alternative (the authors’ null hypothesis) can be also true.