Abnormal Wave Reflections and Left Ventricular Hypertrophy Late After Coarctation of the Aorta Repair.

Michael A Quail,Rebekah Short,Vivek Muthurangu,Jennifer A Steeden,Bejal Pandya,Andrew M Taylor,Abbas Khushnood,Patrick Segers

doi:10.1161/hypertensionaha.116.08763

Michael A Quail, Rebekah Short + Show 6 more

Open Access

https://doi.org/10.1161/hypertensionaha.116.08763

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Abstract

Patients with repaired coarctation of the aorta are thought to have increased afterload due to abnormalities in vessel structure and function. We have developed a novel cardiovascular magnetic resonance protocol that allows assessment of central hemodynamics, including central aortic systolic blood pressure, resistance, total arterial compliance, pulse wave velocity, and wave reflections. The main study aims were to (1) characterize group differences in central aortic systolic blood pressure and peripheral systolic blood pressure, (2) comprehensively evaluate afterload (including wave reflections) in the 2 groups, and (3) identify possible biomarkers among covariates associated with elevated left ventricular mass (LVM). Fifty adult patients with repaired coarctation and 25 age- and sex-matched controls were recruited. Ascending aorta area and flow waveforms were obtained using a high temporal-resolution spiral phase-contrast cardiovascular magnetic resonance flow sequence. These data were used to derive central hemodynamics and to perform wave intensity analysis noninvasively. Covariates associated with LVM were assessed using multivariable linear regression analysis. There were no significant group differences (P≥0.1) in brachial systolic, mean, or diastolic BP. However central aortic systolic blood pressure was significantly higher in patients compared with controls (113 versus 107 mm Hg, P=0.002). Patients had reduced total arterial compliance, increased pulse wave velocity, and larger backward compression waves compared with controls. LVM index was significantly higher in patients than controls (72 versus 59 g/m2, P<0.0005). The magnitude of the backward compression waves was independently associated with variation in LVM (P=0.01). Using a novel, noninvasive hemodynamic assessment, we have shown abnormal conduit vessel function after coarctation of the aorta repair, including abnormal wave reflections that are associated with elevated LVM.

Highlights

Patients with repaired coarctation of the aorta are thought to have increased afterload due to abnormalities in vessel structure and function
The main findings of the study were (1) central SBP was higher in patients compared with controls, there was no significant difference in brachial SBP; (2) patients postcoarctation repair were characterized by lower TAC, higher local wave speed, and increased BCW, without differences in aortic root Zc; and (3) higher LV mass (LVM) was observed in patients and was significantly associated with the magnitude of the BCW
This study aimed to describe all relevant central hemodynamic parameters underlying the vascular abnormalities in coarctation of the aorta (CoA)

Summary

Introduction

Patients with repaired coarctation of the aorta are thought to have increased afterload due to abnormalities in vessel structure and function. Ascending aorta area and flow waveforms were obtained using a high temporal-resolution spiral phase-contrast cardiovascular magnetic resonance flow sequence These data were used to derive central hemodynamics and to perform wave intensity analysis noninvasively. Noninvasive hemodynamic assessment, we have shown abnormal conduit vessel function after coarctation of the aorta repair, including abnormal wave reflections that are associated with elevated LVM. We have recently demonstrated the ability to assess central aortic systolic blood pressure (c-SBP) using a combination of phase-contrast magnetic resonance and oscillometric brachial artery blood pressure.[1] We have shown that it is possible to use the same high temporalresolution phase-contrast magnetic resonance data to perform noninvasive wave intensity analysis (WIA).[2,3] This allows the assessment of wave reflections, which has not previously been done in the CoA population. The aims of the study were to use high temporal-resolution CMR imaging to (1) characterize differences in c-SBP

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