118 Myocardial function by longitudinal global strain correlates to exercise capacity in patients with Hypertrophic Cardiomyopathy

In patients with hypertrophic cardiomyopathy (HCM), left ventricular ejection fraction by Simpson biplane (LVEF2D) has limited value in assessing myocardial contractility. To overcome this limitation, longitudinal global strain (global-ɛ) by speckle tracking could be an alternative.MethodsGlobal-ɛ was assessed in 25 HCM patients (58±13 years, 18 men) with preserved LVEF2D (67±8%, range 50-79), referred for exercise echocardiography. Global-ɛ was compared to exercise capacity and 3D LVEF (LVEF3D).ResultsOn the whole, global-ɛ averaged -16±5% (range –25 to –9) and better correlated to LVEF3D (r=-0.69, p=0.001, see Figure) than to LVEF2D (r=–0.52, p=0.01). Importantly, despite preserved LVEF2D, impaired contractility was observed in 7/25 (28%) patients by 3D echocardiography (LVEF3D <50%) and in 10/25 (40%) by global strain (>-15%). However, only impaired contractility by global-ɛ (>-15%) was associated to a lower exercise duration (5.6±1.8 min with global strain >-15% vs. 7.5±2.2 min with global strain ≤-15%, p=0.03) and a lower expected work load (58±20% vs. 77±12%, p=0.03, see Figure).ConclusionIn patients with HCM and preserved LVEF2D, longitudinal global strain impairment observed in 40% of patient is associated with lower exercise capacity. This suggests that alterations of contractile apparatus could be better identified by longitudinal strain using speckle tracking analysis