Abou Alaiwi S, Roston TM, Marstrand P, Claggett BL, Parikh VN, Helms AS, Ingles J, Lampert R, Lakdawala NK, Michels M, Owens AT, Rossano JW, Saberi S, Abrams DJ, Ashley EA, Semsarian C, Stendahl JC, Ware JS, Miller E, Ryan TD, Russell MW, Day SM, Olivotto I, Vissing CR, and Ho CY
Background: The development of left ventricular systolic dysfunction (LVSD) in hypertrophic cardiomyopathy (HCM) is rare but serious and associated with poor outcomes in adults. Little is known about the prevalence, predictors, and prognosis of LVSD in patients diagnosed with HCM as children., Methods: Data from patients with HCM in the international, multicenter SHaRe (Sarcomeric Human Cardiomyopathy Registry) were analyzed. LVSD was defined as left ventricular ejection fraction <50% on echocardiographic reports. Prognosis was assessed by a composite of death, cardiac transplantation, and left ventricular assist device implantation. Predictors of developing incident LVSD and subsequent prognosis with LVSD were assessed using Cox proportional hazards models., Results: We studied 1010 patients diagnosed with HCM during childhood (<18 years of age) and compared them with 6741 patients with HCM diagnosed as adults. In the pediatric HCM cohort, median age at HCM diagnosis was 12.7 years (interquartile range, 8.0-15.3), and 393 (36%) patients were female. At initial SHaRe site evaluation, 56 (5.5%) patients with childhood-diagnosed HCM had prevalent LVSD, and 92 (9.1%) developed incident LVSD during a median follow-up of 5.5 years. Overall LVSD prevalence was 14.7% compared with 8.7% in patients with adult-diagnosed HCM. Median age at incident LVSD was 32.6 years (interquartile range, 21.3-41.6) for the pediatric cohort and 57.2 years (interquartile range, 47.3-66.5) for the adult cohort. Predictors of developing incident LVSD in childhood-diagnosed HCM included age <12 years at HCM diagnosis (hazard ratio [HR], 1.72 [CI, 1.13-2.62), male sex (HR, 3.1 [CI, 1.88-5.2), carrying a pathogenic sarcomere variant (HR, 2.19 [CI, 1.08-4.4]), previous septal reduction therapy (HR, 2.34 [CI, 1.42-3.9]), and lower initial left ventricular ejection fraction (HR, 1.53 [CI, 1.38-1.69] per 5% decrease). Forty percent of patients with LVSD and HCM diagnosed during childhood met the composite outcome, with higher rates in female participants (HR, 2.60 [CI, 1.41-4.78]) and patients with a left ventricular ejection fraction <35% (HR, 3.76 [2.16-6.52])., Conclusions: Patients with childhood-diagnosed HCM have a significantly higher lifetime risk of developing LVSD, and LVSD emerges earlier than for patients with adult-diagnosed HCM. Regardless of age at diagnosis with HCM or LVSD, the prognosis with LVSD is poor, warranting careful surveillance for LVSD, especially as children with HCM transition to adult care., Competing Interests: Disclosures Dr Ho is a consultant for and receives research funding from Bristol Myers Squib, Pfizer, Cytokinetics, Tenaya, and BioMarin. Dr Parikh receives research funding from BioMarin and consults for Nuevocor and Viz.ai. Dr Lakdawala is a consultant for Bristol Myers Squibb, Pfizer, Cytokinetics, Tenaya, and Sarepta, and receives research funding from Pfizer. Drs Saberi and Michels are consultants for Bristol Myers Squibb and Cytokinetics. Dr Claggett has received personal fees from Amgen, Cardurion, Corvia, Cytokinetics, Intellia, and Novartis outside the submitted work. Dr Ashley is a co-founder of Deepcell, Personalis, and SVEXA, a board member of AstraZeneca, and an adviser to Apple, Foresite Labs, Nuevocor, and Sequencebio. Dr Lampert has received research funding and honoraria from Medtronic and Abbott, honoraria from Boston Scientific, and sat on advisory board for Medtronic. Dr Olivotto is a consultant for or receives research grants from: BMS-Myokardia, Cytokinetics, Boston Scientific, Sanofi Genzyme, Shire Takeda, Amicus, Menarini International, Bayer, and Tenaya. Dr Helms receives research funding from Bristol Myers Squibb and is a consultant for Tenaya and Lexeo Therapeutics. Dr Ingles receives research grant support from Bristol Myers Squibb. Dr Rossano is a consultant for Merck, Bayer, Bristol Myers Squibb, BioMarin, and CRI Biotech. Dr Ware has consulted for MyoKardia (now Bristol Myers Squibb), Foresite Labs, and Pfizer. Dr Abrams is a consultant for Dinaqor. Dr Marstrand has been employed at Novo Nordisk A/S. Novo Nordisk A/S was not involved in this research, and the views presented do not necessarily reflect the views of Novo Nordisk A/S. Drs Alaiwi, Roston, Semsarian, Stendahl, Ryan, Russell, Miller, and Vissing declare no relevant disclosures or competing interests.