Persistent left ventricular outflow tract obstruction was associated with a significantly increased hazard of composite cardiac events compared to intermittent obstruction (HR 4.97).
Cohort (n=114)
No
Does persistent LVOT obstruction and reduced LA strain predict composite cardiac events in pediatric patients with hypertrophic cardiomyopathy?
In pediatric patients with hypertrophic cardiomyopathy, reduced left atrial strain and persistent LVOT obstruction on exercise stress echocardiography are independently associated with an increased risk of adverse cardiac events.
Hazard Ratio: 4.97 (95% CI 1.41–17.6)
p-value: p=0.013
In adults with hypertrophic cardiomyopathy (HCM), left ventricular outflow tract (LVOT) obstruction on exercise stress echocardiography (ESE) and reduced left atrial (LA) strain increase heart failure and cardiac outcome risk. However, limited pediatric data exist. We evaluated the association of exercise-induced LVOT obstruction and LA strain with cardiac events in young HCM patients. Patients who underwent ESE (n = 114, 32%F, median = 17 yrs) from 2014-2022 at a single center were stratified by LVOT gradients: Group 1 (n = 44, rest/exercise gradients < 30mmHg); Group 2 (n = 41, rest < 30mmHg; exercise ≥ 30mmHg); Group 3 (n = 29, rest/exercise ≥ 30mmHg). LA reservoir (LASr), conduit (LAScd), and contractile strain were analyzed with TOMTEC AutoStrain LA. Composite cardiac event included: heart failure, non-sustained/sustained ventricular tachycardia, cardiac syncope, heart transplantation, and HCM-related death. At follow-up (median = 2.0 years), there was a greater hazard of the composite event in Group 3 vs. 2 (hazard-ratio HR = 4.97, p = 0.013). Severe events were rare and largely observed in Group 3. Increased HR was seen in Group 2 vs. 1 but the difference was not significant. Adjusting for LVOT gradient (Group 3), lower LASr or LAScd or increased LA stiffness (E/e' to LASr ratio) were associated with composite event (HR LASr = 1.57; LAScd = 1.70; LA stiffness = 1.31; all p < 0.01). Concordance indices were similar for these three strain/stiffness models (0.81-0.82) and higher than in models including LVOT group with traditional diastolic indices (LA volume index or E/e'; c-index = 0.76). In one of the largest pediatric HCM cohorts undergoing ESE, reduced LA strain demonstrated greater incremental value to LVOT gradient than traditional diastolic indices when evaluating association with cardiac events.
Gearhart et al. (Thu,) conducted a cohort in Pediatric Hypertrophic Cardiomyopathy (n=114). Persistent LVOT obstruction (resting and exercise gradients ≥30 mmHg) vs. Intermittent LVOT obstruction (resting <30 mmHg, exercise ≥30 mmHg) was evaluated on Composite cardiac event (heart failure, ventricular tachycardia, cardiac syncope, heart transplantation, HCM-related death) (HR 4.97, 95% CI 1.41-17.6, p=0.013). Persistent left ventricular outflow tract obstruction was associated with a significantly increased hazard of composite cardiac events compared to intermittent obstruction (HR 4.97).