We appreciate the interest of Drs. de Gregorio and Dr. Andò in our study. Of the many comments and questions raised in their letter, we have selected those that do not find a direct answer in the results published in our report. First, patients with hypertrophic cardiomyopathy (HC) and massive left ventricular hypertrophy (maximal wall thickness ≥30 mm) were excluded from the study because extreme hypertrophy is an acknowledged risk factor and thus inconsistent with our selection of a low-risk cohort. The great majority of our study patients (89%) had a relatively mild left ventricular wall thickness of <25 mm, and only a small minority (<5%) had a wall thickness of 27 to 29 mm (borderline high risk). The number of events in this latter subset was too small to allow wall thickness at the high end of the spectrum (i.e., 27 to 29 mm) to emerge as an independent predictor of sudden death. Second, in our study as in previous HC literature, left ventricular outflow obstruction proved to be a strong and independent determinant of outcome, associated with a high risk of developing severe heart failure symptoms. Third, the institutions participating in the study were referral centers for HC, and all echocardiograms were reported by HC experts. Therefore, a core echocardiographic laboratory was not required. Fourth, although a dilated left atrium emerged as an independent marker of sudden death in our selected cohort without conventional risk factors, the large proportion of patients with HC and left atrial enlargement limits the accuracy of this morphologic feature as a marker for sudden death risk stratification in the individual patient. Finally, the scoring system proposed by O’Mahony et al, which is mentioned as a possible approach to risk stratification, is not suitable for making difficult decisions regarding implantable cardioverter-defibrillators for the primary prevention of sudden death in individual HC patients. We thank Dr. de Gregorio and Dr. Andò for their interest and stimulus to further research, and we encourage them to become principal investigators themselves.