Prevalence of primary aldosteronism and association with cardiovascular complications in patients with resistant and refractory hypertension

Objectives: To assess the prevalence of primary aldosteronism and its association with cardiometabolic complications in patients with resistant and refractory hypertension. Methods: One hundred and ten consecutive patients with true resistant hypertension [insufficient blood pressure control despite appropriate lifestyle measures and treatment with at least three classes of antihypertensive medication, including a diuretic] and without previous cardiovascular events were screened for secondary hypertension. Refractory hypertension was diagnosed in case of uncontrolled blood pressure despite the use of at least five antihypertensive drugs. Results: Primary aldosteronism was diagnosed in 32 cases (29.1%). The multivariate analysis showed that primary aldosteronism is a strong factor positively associated with left ventricular hypertrophy [odds ratio (OR) = 12.98, 95% confidence interval (CI) 3.82-60.88;P < 0.001], microalbuminuria (OR = 3.67, 95% CI 1.44-9.78;P = 0.007), carotid intima-media thickness at least 0.9 mm (OR = 2.69, 95% CI 1.02-7.82;P = 0.037), aortic ectasia (OR = 4.08, 95% CI 1,18-15.04;P = 0.027) and atrial fibrillation (OR 8.80, 95% CI 1.53-73.98;P = 0.022). Moreover, primary aldosteronism was independently associated with the presence of at least one (OR = 8.60, 95% CI 1.73-69.88;P = 0.018) and at least two types of organ damage (OR = 3.08, 95% CI 1.19-8.24;P = 0.022). Thirteen patients (11.8%) were affected by refractory hypertension. This group was characterized by significantly higher values of carotid intima-media thickness, higher rate of aldosterone-producing adenoma and atrial fibrillation, compared with the other individuals with resistant hypertension. Conclusion: The current study indicates that primary aldosteronism is a frequent cause of secondary hypertension and cardiovascular complications among patients with resistant and refractory hypertension, suggesting a crucial role of aldosterone in the pathogenesis of severe hypertensive phenotypes and cardiovascular disease.