Association between circulating angiotensin-converting enzyme 2 and cardiac remodeling in hypertensive patients

Angiotensin-converting enzyme 2 (ACE2) plays a vital role in the pathogenesis of hypertension-induced cardiac remodeling and exhibits cardioprotective properties in hypertensive animal models. Evidence that ACE2 is an important regulator of hypertensive cardiac remodeling in humans has not been addressed directly yet.

A total of 161 patients with essential hypertension and 47 age- and sex-matched normotensive healthy subjects were consecutively recruited. Serum concentration levels of ACE2 were determined by enzyme-linked immunosorbent assay. Cardiac structural and functional parameters were measured by echocardiography.

Serum ACE2 concentrations were higher in hypertensive patients compared to healthy subjects (170.31 [83.50-707.12] pg/ml in patients versus 59.28 [39.71-81.81] pg/ml in healthy subjects, P<0.001). After adjustment for confounders, including age, sex, body mass index, snoring, smoking, duration of hypertension, comorbidities, medication use, mean arterial pressure and N-terminal pro-brain natriuretic peptide, serum ACE2 concentrations were positively correlated with left atrial diameter, left ventricular end-diastolic diameter and left ventricular mass in hypertensive patients. Moreover, multiple regression analyses adjusting for covariates revealed that serum ACE2 concentrations were also independently associated with left ventricular ejection fraction and late diastolic filling velocities of the mitral inflow.

This study reveals an elevated serum concentration of ACE2 and independent associations between serum ACE2 and echocardiographic parameters in hypertensive patients.