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.