Abnormal regional myocardial deformation properties and increased aortic stiffness in normotensive patients with aortic coarctation despite successful correction: an ABPM, standard echocardiography and strain rate imaging study

Abstract

The long-term follow-up data subsequent to a successful repair of AoC (aortic coarctation) show that life expectancy remains reduced. Previous standard echocardiographic studies have demonstrated normal or increased systolic cardiac function in patients following successful repair of AoC. SR (strain rate) imaging is a new technique able to detect subclinical myocardial abnormalities. In the present study we investigated whether young patients (without hypertension, as assessed using ambulatory blood pressure monitoring and an exercise test) following successful AoC repair already have abnormal myocardial deformation properties, and the relationship of the deformation properties with aortic stiffness. We studied 166 subjects, 83 AoC non-hypertensive patients (mean age 12±4 years) a number of years after successful repair of AoC and 83 age- and sex-matched subjects as controls. Peak systolic SR (1/s) for both regional longitudinal and radial function was assessed. The aortic stiffness index was calculated from the echocardiographically derived thoracic aortic diameters, and the measurement of blood pressure was obtained by cuff sphygmomanometry. The LV (left ventricular) ejection fraction was significantly increased in AoC patients, whereas regional longitudinal SRs were significantly reduced (−1.1±0.9 compared with −2±0.5, P<0.0001) in patients. The aortic stiffness index was significantly increased in AoC patients (12±9, P<0.0001). At multilinear regression analysis, age at repair (P=0.005; coefficient, −0.201; S.E.M., 0.027) and the aortic stiffness index (P=0.0029; coefficient, 0.334; S.E.M., 0.423) predicted longitudinal SR. Despite the presence of a successful repair for AoC, in the absence of hypertension, longitudinal deformation properties were significantly impaired. Moreover, the degree of longitudinal SR impairment was correlated with age at repair and aortic stiffness. Early repair can delay the onset of hypertension in postcoarctectomy patients, but cannot prevent the innate structural and functional abnormalities of the aorta and their deleterious effect on myocardial deformation properties.