Exercise Stress Echocardiography Predicts Adverse Cardiovascular Events in Hypertrophic Cardiomyopathy: A 5-Year...

Hypertrophic cardiomyopathy (HCM) is an autosomal dominant genetic disorder and a primary cause of sudden cardiac death (SCD) in young individuals. Studies have demonstrated that "left atrial strain" serves as a predictive marker for adverse cardiovascular events in diseases such as heart failure with preserved ejection fraction, moderate aortic stenosis, and diastolic dysfunction. Therefore, this study used exercise stress echocardiography (ESE) to identify high-risk factors in the early stages of HCM.

A total of 142 HCM patients, diagnosed at the Sichuan Provincial People's Hospital in Chengdu, China, between 2017 and 2018, were included, along with 80 age- and gender-matched normal controls. ESE was employed to examine all subjects, and a 5-year follow-up of the HCM patients was conducted. HCM patients were classified into positive event and non-event groups based on follow-up results. Comparisons were made between the groups, focusing on left atrial reservoir strain, conduit strain, contractile strain, left ventricular global longitudinal strain at rest and peak exercise, and strain reserve.

(1) Significant impairments in global longitudinal strain (GLS), left atrial reservoir strain (LASr), and reserve function were observed in the positive events group: the resting (R) 4D and 2D GLS (R_4D_GLS: -13.20 ± 3.35; R_2D_GLS: -17.13 ± 3.71), and peak (P) 2D GLS (P_2D_GLS: -14.45 ± 3.51) were reduced (p < 0.05), accompanied by deteriorated GLS reserves (Δ2D_GLS: -2.68 ± 2.78; Δ2D_GLS %: -13.57% ± 18.89%; p < 0.05). The resting 2D and 4D left atrial (LA) reservoir strain at end-diastole (R_LASr_ED: 14.36 ± 5.52; R_4D_LASr: 10.30 ± 3.24) and peak 2D LASr (P_LASr_ED: 12.18 ± 5.71) were significantly impaired (p < 0.05), with a notable loss in reserve capacity (ΔLASr_ED: -2.18 ± 4.03; ΔLASr_ED %: -14.19% ± 27.85%; p < 0.05). (2) Correlations: positive events demonstrated strong correlations with R_4D_LASr (r = -0.67), R_LASr_ED (r = -0.58), P_LASr_ED (r = -0.61), and P_2D_GLS (r = 0.58). The positive events showed a weak linear association with the rest left ventricular outflow tract pressure gradient (R_LVOT-PG)(r = 0.35) and an "inverted U-shaped" relationship with the peak left ventricular outflow tract pressure gradient (P_LVOT-PG). (3) Logistic regression and collinearity analysis showed that the R_4D_LASr (odds ratio (OR) = 0.655, 95% confidence interval (CI) 0.547-0.783) and P_2D_GLS (OR = 1.383, 95% CI 1.142-1.675) were independent predictors for positive events.

ESE provides critical information to predict risk factors in HCM patients: R_4D_LASr and P_2D_GLS have independent predictive values for positive cardiovascular events, which can assist in clinical assessment and the identification of high-risk HCM patients, promote individualized and precise risk stratification of HCM in clinical practice, and improve long-term prognosis.