Fast long-axis strain: a simple, automatic approach for assessing left ventricular longitudinal function with cine cardiovascular magnetic resonance.

ABSTRACT

OBJECTIVES: In some cardiac pathologies, impairment of left ventricular (LV) longitudinal function may precede reduction in LV ejection fraction. This study investigates the effectiveness of a fast method to quantify long-axis LV function compared to conventional feature tracking and manual approaches. METHODS: The study consisted of 50 normal controls and 100 heart failure (HF) patients including 40 with reduced ejection fraction (HFrEF), 30 with mid-range ejection fraction (HFmrEF), and 30 with preserved ejection fraction (HFpEF). Parameters including fast long-axis strain (FLAS) at end-systole and peak strain rates during systole (FLASRs), early diastole (FLASRe), and atrial contraction (FLASRa) were derived by a fast semi-automated approach on cine cardiovascular magnetic resonance. RESULTS: FLAS exhibited good agreement with strain values obtained using conventional feature tracking (bias - 2.9%, limits of agreement ± 3.0%) and the manual approach (bias 0.6%, limits of agreement ± 2.1%), where FLAS was more reproducible and required shorter measurement time. The mean FLAS (HFrEF < HFmrEF < HFpEF < controls; 6.1 ± 2.4 < 9.9 ± 2.4 < 11.0 ± 2.5 < 16.9 ± 2.3%, all p < 0.0001) was decreased in all the HF patient groups. A FLAS of 12.3% (mean-2SD of controls) predicted the presence of systolic dysfunction in 67% of patients with HFpEF, and 87% with HFmrEF. Strain parameters using the fast approach were superior to those obtained by conventional feature tracking and manual approaches for discriminating HFpEF from controls. Notable examples are area under the curve, sensitivity, and specificity for FLAS (0.94, 93%, and 86%) and FLASRe (0.96, 90%, and 94%). CONCLUSIONS: The fast approach-derived LV strain and strain rate parameters facilitate reproducible, reliable, and effective LV longitudinal function analysis. KEY POINTS • Left ventricular long-axis strain can be rapidly derived from cine CMR with shorter measurement time and higher reproducibility compared to conventional feature tracking and the manual approach. • Progressive reductions in left ventricular long-axis strain and strain rate measurements were observed from HFpEF, HFmrEF, to HFrEF group. • Based on long-axis strain, systolic abnormalities were evident in HFmrEF and HFpEF indicating common coexistence of systolic and diastolic dysfunction in the HF phenotypes.