Abstract 17788: Repaired Coarctation is Associated With Central Hypertension, Increased Vessel Stiffness and Abnormal Wave Reflections - A Novel CMR Hemodynamics Study
Introduction: The basis of late cardiovascular mortality following coarctation repair is poorly understood. Although hypertension has been implicated, peripheral systolic pressure (pSBP) has not been shown to be definitively higher in this group. This may be because mortality is more related to central systolic pressure (cSBP) than pSBP. We have developed a novel cardiovascular magnetic resonance (CMR) protocol that allows assessment of cSBP and it components: resistance, compliance and wave reflections. The main aims of this study were i) characterize hemodynamic differences between patients and controls ii) define hemodynamic determinants of cSBP in patients and iii) Identify possible biomarkers amongst covariates associated with LV mass (LVM).
Methods: 75 subjects, 50 patients with repaired coarctation, median age 23.5yrs (74% male) and 25 matched controls; 21.0yrs (72% male) were recruited. Ascending aorta area and flow waveforms were obtained using a high temporal resolution (10ms) spiral phase-contrast MR flow sequence. This data was used to derive cSBP and perform wave intensity analysis (WIA) non-invasively using previously validated techniques. The determinants of cSBP and LVM were assessed using multivariable linear regression analysis.
Results: Central SBP was significantly higher in patients compared to controls (115±13 vs 107±9mmHg [mean±sd], p=0.002). However, there was only a trend towards higher pSBP (123±15 vs 117±11mmHg, p=0.052). Patients had reduced arterial compliance, increased characteristic impedance and larger backward compression waves (BCW) than controls; and these parameters were independently associated with cSBP. LVM index was significantly higher in patients than controls (73.1±14.6 vs 58.9±9.7g/m2, p=0.0001). Independent predictors of LVM included cSBP (p=0.001) and BCW (p=0.002), but importantly not pSBP or coarctation index.
Conclusions: Non-invasive assessment of fundamental arterial hemodynamics by CMR is feasible. Using these techniques we have shown elevated cSBP in patients after coarctation repair. Elevated cSBP and BCW are important determinants of increased LVM following coarctation repair. These metrics represent superior biomarkers of afterload than coarctation index and pSBP.
Author Disclosures: M.A. Quail: None. R. Short: None. B. Pandya: None. J.A. Steeden: None. A. Khushnood: None. P. Segers: None. V. Muthurangu: None.
- © 2015 by American Heart Association, Inc.