Conventional risk factors for sudden cardiac death (SCD) justify primary prevention through implantable cardioverter-defibrillator (ICD) implantation in hypertrophic cardiomyopathy (HCM) patients. However, the positive predictive values for these conventional SCD risk factors are low.
The aims of this study were to evaluate whether an elevated intraventricular pressure gradient (IVPG), including　Left ventricular outflow tract obstruction (LVOTO) or midventricular obstruction (MVO), is a potential risk modifier for SCD and ventricular arrhythmias requiring ICD interventions in addition to the conventional risk factors among HCM patients receiving ICDs for primary prevention.
The result that their findings showed that a baseline IVPG ≥ 30 mmHg was associated with an increased risk of experiencing SCD or appropriate ICD interventions among HCM patients who received ICDs for primary prevention. Combined with nonsustained ventricular tachycardia(NSVT), which is a conventional risk factor, a baseline IVPG ≥ 30 mmHg may be a potential modifier of SCD risk in HCM patients.

Kyoichiro Yazaki, Atsushi Suzuki, Tsuyoshi Shiga, Yuichiro Minami, Kotaro Arai, Kyomi Ashihara, Morio Shoda & Nobuhisa Hagiwara , "Left intraventricular pressure gradient in hypertrophic cardiomyopathy patients receiving implantable cardioverter-defibrillators for primary prevention", BMC Cardiovascular Disorders, Published Online (2021) .