Cardiac Remodeling and Disease Progression in Patients With Repaired Coarctation of Aorta and Aortic Stenosis

Background: Valvulo-arterial impedance (Zva) is used for assessment of left ventricular (LV) global pressure load in patients with aortic stenosis (AS) and impaired arterial compliance. Because patients with repaired coarctation of aorta (COA) have impaired arterial compliance, we hypothesized that COA patients with greater than or equal to moderate AS (AS-COA group) will have higher Zva, symptomatic progression, and cardiovascular events, as compared to non-COA patients with similar AS severity (AS group). Methods: Propensity matching (1:1) of 71 AS-COA and 71 AS patients based on age, sex, body mass index, and aortic valve mean gradient (cohort 1). Of 172 patients, 117 patients (AS-COA [n=62]; AS [n=55]) underwent aortic valve replacement, cohort 2. Cohort 1 was used to assess the relationship between preoperative Zva, cardiac remodeling, and symptomatic progression, while cohort 2 was used to assess the relationship between postoperative Zva, LV mass index regression (reduction in LV mass index after aortic valve replacement), and cardiovascular events. Results: The AS-COA group had higher Zva (4.2±0.6 versus 3.5±0.4 mm Hg/mL·m², P<0.001), more advanced cardiac remodeling, and higher 5-year incidence of symptomatic progression (85% versus 51%, P<0.001). Preoperative Zva was independently associated with cardiac remodeling (r=0.66, P<0.001) and symptomatic progression (hazard ratio, 1.06 [1.02-1.10], per mm Hg/mL·m²increase in Zva). The AS-COA group had higher postoperative Zva (3.3±0.5 versus 2.4±0.4 mm Hg/mL·m², P<0.001), less robust LV mass index regression at 1-year post-aortic valve replacement, and higher 5-year incidence of cardiovascular events. Postoperative Zva was independently associated with LV mass index regression (r=-0.46, P<0.001) and cardiovascular events (hazard ratio, 1.06 [1.02-1.10], per mm Hg/mL·m²increase in Zva). Conclusions: Adults with AS-COA had higher LV global pressure load, cardiac remodeling, symptomatic progression, and cardiovascular events as compared to non-COA patients with similar severity of AS. Zva can identify patients at risk for adverse outcomes, and perhaps should be used for risk stratification with regards to timing of aortic valve replacement.