Myocardial Work in Nonobstructive Hypertrophic Cardiomyopathy: Implications for Outcome

Area of Science:

• Cardiology
• Echocardiography
• Cardiovascular Physiology

Background:

• Noninvasive left ventricular (LV) pressure-strain loop analysis is an emerging echocardiographic method.
• It integrates longitudinal strain and blood pressure to estimate myocardial work.
• Hypertrophic cardiomyopathy (HCM) is characterized by LV hypertrophy and diastolic dysfunction.

Purpose of the Study:

• To describe global and segmental myocardial work in patients with nonobstructive HCM.
• To assess the correlation between myocardial work and other echocardiographic parameters.
• To evaluate the association of myocardial work with adverse outcomes in HCM patients.

Main Methods:

• 110 patients with nonobstructive HCM and 35 controls underwent echocardiography.
• Myocardial work indices included myocardial work index, constructive work (CW), wasted work, and cardiac efficiency.
• Combined endpoint included mortality, transplantation, heart failure hospitalization, and cardiac events.

Main Results:

• Patients with HCM showed significantly reduced global CW, cardiac efficiency, and increased wasted work compared to controls.
• Segmental CW impairment correlated with maximal wall thickness.
• Global CW correlated negatively with LV wall thickness, diastolic function, and QRS duration.
• Lower global CW (<1,730 mm Hg%) was associated with poorer event-free survival.

Conclusions:

• Noninvasive assessment of myocardial work using echocardiography is reduced in nonobstructive HCM.
• Reduced myocardial work correlates with LV wall thickness and predicts worse long-term outcomes.
• This method offers a valuable tool for evaluating HCM severity and prognosis.