Comparison of Cardiovascular Complications in Patients with and without KCNJ5 Gene Mutations Harboring Aldosterone-producing Adenomas

Aim: Our objective was to evaluate the incidence of cardiovascular complications before and after unilateral adrenalectomy in patients with and without KCNJ5 gene mutations harboring aldosterone-producing adenoma (APA). Methods: A total of 108 APA patients were evaluated in the present study. We compared the clinical characteristics and laboratory findings according to the cardiovascular complications in the patients with or without KCNJ5 gene mutations harboring APA after excluding five APA patients with ATPase or CACNA1D gene mutations. Results: There were 75 and 28 APA patients with somatic mutations of KCNJ5 (p.G151R, p.L168R, p.E145Q, p.T158A or 157del) and no mutations, respectively. There were no double mutations in any of the subjects. The KCNJ5-mutated and wild type groups demonstrated similar advances in left ventricular hypertrophy prior to surgery, although the mutated group was significantly younger, with higher plasma and urine aldosterone levels, than the wild type group (48.2 vs. 55.8 (years old); p<0.001, 436.0 vs. 247 (pg/mL); p<0.001, 22.2 vs. 12.6 (mu g/day); p=0.008). Both groups displayed postoperative improvements in hyperaldosteronism and hypertension. Moreover, the LV mass index (LVMI) significantly improved after surgery in the mutated group (p<0.001), but not in the wild type group (p=0.256). A multiple linear regression analysis showed that an improvement in the LVMI was independently associated with KCNJ5 mutations and the plasma aldosterone level in that order (p=0.034, 0.050, respectively). Conclusion: The present findings clearly demonstrated that KCNJ5 mutations are common among Japanese APA patients (frequency: 69.4%). In this study, the KCNJ5-mutated group demonstrated significant postoperative improvements in LVMI, possibly due to strong autonomous aldosterone production. Hence, it is necessary to precisely diagnose younger APA patients possessing a strong capacity for aldosterone production due to KCNJ5 gene mutations, as such cases may be easily complicated by cardiovascular events.