1348910 - Novel Temporal Strain Parameters to Assess Dyssynchrony Using fSENC in Congenital Heart Disease

Strain imaging provides a noninvasive method to assess cardiac deformation. Patients with congenital heart disease (CHD) are at risk for abnormal myocardial deformation and cardiac dyssynchrony. Fast- strain encoded (fSENC) cardiac magnetic resonance (CMR) is a method to assess myocardial deformation. Novel strain parameters: standard deviation of time to peak strain (SD-TPS), strain curvature which demonstrates the transition from systole to diastole, strain correlation which represents synchronization of regional strain curves, pre-and post-systolic septal slope, which assess change in regional strain during systole and diastole, respectively, can be markers of dyssynchrony.

Methods:

A total of 50 patients underwent CMR with fSENC for clinical indications among which 29 were CHD, 6 were normal and 15 had cardiomyopathy. The percentage of myocardial segments with strain <-17%, defined as MyoHealth®, and strain parameters including SD-TPS, strain curvature, and strain correlation were compared between these cohorts. Normal MyoHealth® was defined as >80% of myocardial segments with normal strain. The impact of pressure or volume loading lesions on the myocardial mechanics was assessed.

Results:

Twenty-nine CHD patients mean age 21 +8 years, among which 15/29 (52%) had moderate complexity CHD, 6/29 (20%) had severe CHD underwent fSENC with mean MyoHealth ® 61+17%.  Patients with CHD had worse overall MyoHealth ® (p< 0.01), SD-TPS (p < 0.01), longitudinal strain correlation (p< 0.001), pre-and post-systolic septal slope (p< 0.001) compared to normal patients (Figure 1). Patients with repaired Tetralogy of Fallot (TOF) had worse MyoHealth® (p = 0.02), SD-TPS (p <0.01), longitudinal strain correlation (p<0.01) and post systolic septal slope (p = 0.09) compared to normal patients (Figure 2). Furthermore, residual pulmonary stenosis and pulmonary regurgitation in patients with repaired TOF was associated with worse right ventricular MyoHealth®, SD-TPS, and post systolic slope (Figure 3).  Patients with single ventricle anatomy status post Fontan procedure had lower MyoHealth® compared to normal patients and patients with other forms of CHD (Figure 3). Patients with complex CHD had worse myocardial deformation and evidence of dyssynchrony compared to those with simple or moderate CHD.

Conclusion: This is the first study to describe the use of novel strain parameters to assess subclinical ventricular dysfunction in patients with congenital heart disease using fSENC CMR. MyoHealth® may be an early indicator of worsening myocardial mechanics in response to pressure and volume overload in patients with CHD. Temporal strain parameters including SD-TPS, strain curvature and strain correlation may help identify early dyssynchrony and effects of remodeling in CHD patients.