Value of Strain Imaging and Maximal Oxygen Consumption in Patients With Hypertrophic Cardiomyopathy

Moneghetti KJ; Stolfo D; Christle JW; Kobayashi Y; Finocchiaro G; Sinagra G; Myers J; Ashley
EA; Haddad F; Wheeler MT,

The American Journal Of Cardiology [Am JCardiol], ISSN: 1879-1913, 2017 Oct 01; Vol. 120 (7), pp. 1203-1208;

Longitudinal strain (LS) has been shown to be predictive of outcome in hypertrophic
cardiomyopathy (HC). Percent predicted peak oxygen uptake (ppVO2),
among other cardiopulmonary exercise testing (CPX) metrics, is a strong
predictor of prognosis in HC. However, there has been limited
investigation into the combination of LS and CPX metrics. This study
sought to determine how LS and parameters of exercise performance
contribute to prognosis in HC. One hundred and thirty-one consecutive
patients with HC who underwent CPX and stress echocardiography were
included. Global, septal, and lateral LS were assessed at rest and
stress. Eighty matched individuals were used as controls. Patients were
followed for the composite end point of death and worsening heart
failure. All absolute LS components were lower in patients with HC than
in controls (global 14.3 ± 4.0% vs 18.8 ± 2.2%, p <0.001; septal
11.9 ± 4.9% vs 17.9 ± 2.7%, p <0.001; lateral 16.0 ± 4.7% vs
19.4 ± 3.1%, p = 0.001). Global strain reserve was also reduced in
patients with HC (13 ± 5% vs 19 ± 8%, p = 0.002). Over a median
follow-up of 56 months (interquartile range 14 to 69), the composite
end point occurred in 53 patients. Global LS was predictive of outcome
on univariate analysis (0.55 [0.41 to 0.74], p <0.001). When combined
with CPX metrics, lateral LS was the only strain variable predictive of
outcome along with indexed left atrial volume (LAVI) and ppVO2. The
worst outcomes were observed for patients with lateral LS <16.1%, LAVI
>52 ml/m2, and ppVO2 <80%. The combination of lateral LS, LAVI, and
ppVO2 presents a simple model for outcome prediction.