Usefulness of cardiac fusion imaging with computed tomography and Doppler echocardiography in the assessment of conduit stenosis in complex adult congenital heart disease

Noninvasive assessment of stenotic lesions in patients with complex adult congenital heart disease (ACHD) is challenging due to its complex morphology. The simultaneous two-screen display of multidetector-computed tomography (MDCT) and real-time echogram (STDME) technology can display a virtual multi-planar reconstruction from MDCT corresponding to the same cross-sectional image from transthoracic echocardiography (TTE). We investigated the usefulness of the STDME technology for stenosis severity assessment in complex ACHD patients.Twenty-four complex ACHD patients with stenotic lesions were enrolled in this study. All patients underwent TTE and the STDME technology within a week after MDCT. Peak velocity and pressure gradient (PG) across the stenotic site were measured using continuous wave Doppler. Cardiac catheterization was performed in 17 patients.Nine out of the twenty-four patients had undergone repair with a conduit. Peak velocity and PG from the STDME technology were higher than those from TTE (peak velocity: 3.1 ± 1.1 vs. 2.8 ± 1.0 m/s; peak PG: 43 ± 28 vs. 34 ± 21 mmHg; both p0.01). Peak PG from the STDME technology showed significant correlations with those from catheterization in patients with a conduit (n=7) and those without a conduit (n=10) (r = 0.795 and 0.880, respectively; both p0.05), while peak PG from TTE was correlated with catheterization measurements only in patients without a conduit (r = 0.850, p0.05).The STDME technology enables more accurate assessment of conduit stenosis severity than does TTE in complex ACHD patients.