IJCS | Volume 33, Nº1, January / February 2019

9 In our study, most patients who underwent CoA surgical correction had systolic heart murmur with posterior radiation at diagnosis, and half of them had hypertension, cardiac symptoms, and no palpable pulse in the lower limbs. Of note, these findings were achieved by proper physical examination and history-taking, which can guide complementary investigation focused on early diagnosis. Yet, half of patients were lately diagnosed in our follow-up, which is in accordance with previous large population-based studies showing late diagnosis rates of over 62%. 8 Whether late correction constitutes an independent risk factor for poor prognosis remains a matter of debate, with some suggesting a relationship of late correction with re-coarctation rates 6 and others with long-term cardiovascular mortality. In our study, neither re- coarctation nor clinical outcomes differed in a significant manner between age groups. Still, an earlier surgical treatment of comorbidities that are known to have an impact on cardiovascular mortality would presumably improve long-termsurvival. This hypothesis is supported by the absence of LV hypertrophy and cardiac symptoms in operated patients in our analysis. It is of note that more than one third of patients remained hypertensive after surgical correction. This finding is in accordance with previous studies suggesting hypertension as the main late complication in operated patients, even in the absence of residual obstruction. 9,11 Although the exact mechanism for this phenomenon remains unclear, a role of arterial stiffness, endothelial dysfunction and altered autonomic cardiac modulation has been proposed. In thismatter, post-coartectomy subjects have impaired endothelial function, which, in turn, increases peripheral vascular resistance, leading to increased blood pressure. 10 Moreover, coarctation leads to deposition of collagen and depletion of smooth muscle in the aortic wall. This negatively affects aortic distensibility and the sensitivity of aortic arch baroreceptors, thereby impairing arterial compliance with substantial effects on blood pressure. 15,16 Finally, it has been conjectured that hypertension results from compensatory sympathetic stimuli in response to acute unloading of the baroreceptors following surgery. 10 Importantly, these features are not prevented by surgical correction, reinforcing that coarctation is a generalized vasculopathy far beyond the narrowing of the aortic arch. Our study found a high prevalence of LV hypertrophy at baseline, which markedly decreased after surgical correction. Noteworthy, in coarctation, an increase in LV mass occurs in spite of elevated blood pressure, which may be explained by the “ventricular-arterial coupling” hypothesis, that postulates that aortic stiffness increases wave reflection pressure, leading to LV afterload. 17 Importantly, such phenomenon leads to diastolic dysfunction and changes in LV morphology, which are partially reversed by surgery, as demonstrated in the present study and in previous ones. 4,18-20 In fact, in our follow-up we found a significant reduction of indexed LV diameters, LV mass and posterior wall thickness in operated patients who did not manifest recoarctation. Finally, pulmonary hypertension occurred in 12% of patients in our follow-up, which is in accordance with previous studies. Mechanistically, it is assumed that endothelial dysfunction and arterial stiffness are the Table 5 - Clinical variables before and after surgical correction NYHA Baseline (n = 60) Last exam Control a (n = 22) Recoarctation b (n = 14) Bicuspid aortic valve c (n = 11) I 24 (40) 21 (95.5) # 5 (35.7)* 10 (90.9) # II 14 (23.2) 1 (4.5) 8 (57.1) 1 (9.1) III 12 (20) - 1 (7.1) - IV 10 (16.7) - - - Values are n (%). #p < 0.001 compared with baseline; chi-square test; *p < 0.001 compared with control; chi-square test; a patients without bicuspid aortic valve at diagnosis and without recoarctation in the last echocardiographic test; b absence of BAV at diagnosis, and presence of recoarctation in the last echocardiographic test; c BAV at diagnosis, and absence of recoarctation in the last echocardiographic test; NYHA: New York Heart Association classification for heart failure symptoms; BAV: bicuspid aortic valve. Barreto et al. Follow-up of surgically corrected coarctation of the aorta Int J Cardiovasc Sci. 2020;33(1):3-11 Original Article