The Captopril Challenge Test Predicts Cardiac Structure and Dysfunction in Primary Aldosteronism

Context: The captopril challenge test (CCT) is a commonly used confirmation test that identifies the magnitude of renin- and angiotensin II-independent aldosterone production, and thus the presence and severity of primary aldosteronism (PA).

Objective: This study investigated the association between the post-CCT plasma aldosterone concentration (PAC) and cardiovascular remodeling and diastolic dysfunction.

Methods: A total of 540 PA patients with complete CCT and echocardiographic data were retrospectively analyzed. Clinical and echocardiographic parameters were assessed at baseline and 1 year after PA-targeted treatment.

Results: The post-CCT PAC showed a significant linear association with both left ventricular mass index (LVMI) and E/e' in restricted cubic spline analyses, indicating a continuum of risk linked to post-captopril aldosterone levels. In linear regression analyses, post-CCT PAC was significantly associated with baseline LVMI, E/e' and left atrial volume index (LAVI), regardless of multiple model adjustments. One year after PA-targeted treatment, patients with higher post-CCT PAC experienced the greatest improvements in LVMI, E/e' and LAVI. In contrast, baseline aldosterone levels were associated only with baseline LVMI and its improvement after treatment but not with the baseline or improvement of E/e' or LAVI.

Conclusion: Higher post-CCT PAC was significantly associated with worse left ventricular remodeling and diastolic dysfunction, but also greater improvements in cardiac structure and dysfunction following targeted treatment. These findings highlight the prognostic and therapeutic values of the CCT that the post-CCT PAC predicts the severity of cardiac disease and also the potential for therapeutic benefits in PA.