TY - JOUR
T1 - Rest and Stress Longitudinal Systolic Left Ventricular Mechanics in Hypertrophic Cardiomyopathy
T2 - Implications for Prognostication
AU - Pozios, Iraklis
AU - Pinheiro, Aurelio
AU - Corona-Villalobos, Celia
AU - Sorensen, Lars L.
AU - Dardari, Zeina
AU - Liu, Hong yun
AU - Cresswell, Kenneth
AU - Phillip, Susan
AU - Bluemke, David A.
AU - Zimmerman, Stefan L.
AU - Abraham, M. Roselle
AU - Abraham, Theodore P.
N1 - Funding Information:
This work was supported by a grant from the National Institutes of Health (HL 9804006). Dr. Pozios was supported by the Hellenic Society of Cardiology.
Publisher Copyright:
© 2017 American Society of Echocardiography
Copyright:
Copyright 2018 Elsevier B.V., All rights reserved.
PY - 2018/5
Y1 - 2018/5
N2 - Background: Exercise intolerance is the most common symptom in hypertrophic cardiomyopathy (HCM). We examined whether inability to augment myocardial mechanics during exercise would influence functional performance and clinical outcomes in HCM. Methods: Ninety-five HCM patients (32 nonobstructive, 32 labile-obstructive, 31 obstructive) and 26 controls of similar age and gender distribution were recruited prospectively. They underwent rest and treadmill stress strain echocardiography, and 61 of them underwent magnetic resonance imaging. Mechanical reserve (MRES) was defined as percent change in systolic strain rate (SR) immediately postexercise. Results: Global strain and SR were significantly lower in HCM patients at rest (strain: nonobstructive, −15.6 ± 3.0; labile-obstructive, −15.9 ± 3.0; obstructive, −13.8 ± 2.9; control, −17.7% ± 2.1%, P <.001; SR: nonobstructive, −0.92 ± 0.20; labile−obstructive, −0.94 ± 0.17; obstructive, −0.85 ± 0.18; control, −1.04 ± 0.14 s−1, P =.002); and immediately postexercise (strain: nonobstructive, −15.6 ± 3.0; labile-obstructive, −17.6 ± 3.6; obstructive, −15.6 ± 3.6; control, −19.2 ± 3.1%; P =.001; SR: nonobstructive, −1.41 ± 0.37; labile-obstructive, −1.64 ± 0.38; obstructive, −1.32 ± 0.29; control, −1.82 ± 0.29 s−1, P <.001). MRES was lower in nonobstructive and obstructive compared with labile-obstructive and controls (51% ± 29%, 54% ± 31%, 78% ± 38%, 77% ± 30%, P =.001, respectively). Postexercise SR and MRES were associated with exercise capacity (r = 0.47 and 0.42, P <.001 both, respectively). When adjusted for age, gender, body mass index, E/e’ and resting peak instantaneous systolic gradient, postexercise SR best predicted exercise capacity (r = 0.74, P =.003). Postexercise SR was correlated with extent of late gadolinium enhancement (r = 0.34, P =.03). By Cox regression, exercise SR and MRES predicted ventricular tachycardia/ventricular fibrillation (VT/VF) even after adjustment for age, gender, family history of sudden cardiac death, septum ≥ 3 cm and abnormal blood pressure response (P =.04 and P =.046, respectively). Conclusions: Nonobstructive and obstructive patients have reduced MRES compared with labile-obstructive and controls. Postexercise SR correlates with LGE and exercise capacity. Exercise SR and MRES predict VT/VF.
AB - Background: Exercise intolerance is the most common symptom in hypertrophic cardiomyopathy (HCM). We examined whether inability to augment myocardial mechanics during exercise would influence functional performance and clinical outcomes in HCM. Methods: Ninety-five HCM patients (32 nonobstructive, 32 labile-obstructive, 31 obstructive) and 26 controls of similar age and gender distribution were recruited prospectively. They underwent rest and treadmill stress strain echocardiography, and 61 of them underwent magnetic resonance imaging. Mechanical reserve (MRES) was defined as percent change in systolic strain rate (SR) immediately postexercise. Results: Global strain and SR were significantly lower in HCM patients at rest (strain: nonobstructive, −15.6 ± 3.0; labile-obstructive, −15.9 ± 3.0; obstructive, −13.8 ± 2.9; control, −17.7% ± 2.1%, P <.001; SR: nonobstructive, −0.92 ± 0.20; labile−obstructive, −0.94 ± 0.17; obstructive, −0.85 ± 0.18; control, −1.04 ± 0.14 s−1, P =.002); and immediately postexercise (strain: nonobstructive, −15.6 ± 3.0; labile-obstructive, −17.6 ± 3.6; obstructive, −15.6 ± 3.6; control, −19.2 ± 3.1%; P =.001; SR: nonobstructive, −1.41 ± 0.37; labile-obstructive, −1.64 ± 0.38; obstructive, −1.32 ± 0.29; control, −1.82 ± 0.29 s−1, P <.001). MRES was lower in nonobstructive and obstructive compared with labile-obstructive and controls (51% ± 29%, 54% ± 31%, 78% ± 38%, 77% ± 30%, P =.001, respectively). Postexercise SR and MRES were associated with exercise capacity (r = 0.47 and 0.42, P <.001 both, respectively). When adjusted for age, gender, body mass index, E/e’ and resting peak instantaneous systolic gradient, postexercise SR best predicted exercise capacity (r = 0.74, P =.003). Postexercise SR was correlated with extent of late gadolinium enhancement (r = 0.34, P =.03). By Cox regression, exercise SR and MRES predicted ventricular tachycardia/ventricular fibrillation (VT/VF) even after adjustment for age, gender, family history of sudden cardiac death, septum ≥ 3 cm and abnormal blood pressure response (P =.04 and P =.046, respectively). Conclusions: Nonobstructive and obstructive patients have reduced MRES compared with labile-obstructive and controls. Postexercise SR correlates with LGE and exercise capacity. Exercise SR and MRES predict VT/VF.
KW - Arrhythmia
KW - Exercise echocardiography
KW - Hypertrophic cardiomyopathy
KW - Mechanics
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U2 - 10.1016/j.echo.2017.11.002
DO - 10.1016/j.echo.2017.11.002
M3 - Article
C2 - 29426649
AN - SCOPUS:85044765870
VL - 31
SP - 578
EP - 586
JO - Journal of the American Society of Echocardiography
JF - Journal of the American Society of Echocardiography
SN - 0894-7317
IS - 5
ER -