[Long-term follow-up in patients operated on for aortic coarctation. The echo-Doppler and MRI assessment of left ventricular function and the transisthmic gradient]

Abstract

Background: Hyperdynamic left ventricular function and increased left ventricular mass has been recently reported in the long-term follow-up of patients after successful repair of aortic coarctation (AoCo).

Methods: We studied 35 patients, mean age 22.7 years (range 1-47), following repair of AoCo in order to evaluate: 1) left ventricular mass and systolic function by M-mode echocardiography in comparison with 20 healthy control subjects; 2) the prevalence of systemic hypertension; 3) systolic blood pressure and the trans-isthmic gradient by CW Doppler at rest and after exercise; 4) subjects with a hypertensive response and/or with a significant trans-isthmic gradient during exercise, correlating such parameters with indexes of left ventricular function and the ratio of aortic isthmus/aortic diaphragmatic diameters (AOI/AOD) by means of Magnetic Resonance (MR). At the time of operation, mean age was 12.4 years (range 1 mo-40 yrs) and the follow-up period was 10.1 years (range 6 mo-26 yrs).

Results: Left ventricular mass index (Mi) was significantly greater in comparison with that of the controls (96.5 +/- 25 vs 71.5 +/- 16.6 g/m2; p < 0.001); the mean velocity of circumferential shortening (mVCFc) was increased (1.4 +/- 0.25 vs 1.2 +/- 0.16 circ/s; p < 0.005); the end systolic meridional stress (ESS) was decreased (37.3 +/- 11.1 vs 47.9 +/- 13.1 g/cm2; p < 0.005) while the peak systolic meridional stress (PSS) was not significantly different in the two groups. Fourteen out of 35 patients (40%) showed an exaggerated mVCFc for the level of ESS, which indicates an increased inotropic state. Hypertension at rest was present in 10 patients (28%). Mean age at the time of operation of the hypertensive group was higher than that of the normotensive one (21.4 +/- 10 vs 8.9 +/- 8.6 yrs; p < 0.001). All patients showed a small systolic gradient across the side of coarctation repair at rest (mean 13.1 mmHg; range 0-30). The exercise test was stopped in 5 patients because of hypertension (> 250 mmHg); 24 patients (80%) showed an exercise-induced hypertension. The mean gradient at maximal exercise was 25.9 mmHg (range 0-52); 6 patients (20%) developed a diastolic gradient. With MR it was possible to evaluate the anatomy of the aortic arch and the descending aorta in all cases. The mean ratio AOI/AOD was 0.81 (range 0.63-1). The age at the time of operation showed a positive correlation with the systolic blood pressure (r = 0.63; p < 0.001) and with Mi (r = 0.45; p < 0.005). The systolic blood pressure and the gradient at maximal exercise also showed a positive correlation (r = 0.40; p < 0.01).

Conclusions: In the long-term follow-up of patients after successful coarctation repair there are persistent alterations of left ventricular function with hypertrophy, hyperkinesia and increased inotropic state. Hypertension at rest and after exercise could persist despite good surgical results.