Tissue Sodium Quantification in Patients With Primary Aldosteronism: See Sodium to Treat

Arterial hypertension is a major modifiable cardiovascular risk factor along with diabetes mellitus. Hypertension due to autonomous elevation in aldosterone production (Primary Aldosteronism; PA) is not responsive to usual antihypertensive medications and is dramatically underdiagnosed in standard clinical routine. Currently, only 0.1% (1,280,000 worldwide and 1,140 Singaporeans) are diagnosed, much lower than the 5-20% (64,000,000-256,000,000 worldwide and 57,000-228,000 Singaporeans) of all patients with arterial hypertension estimated to suffer from PA. Given the high prevalence of PA, low rates of diagnoses, high cardiometabolic morbidity and mortality associated with untreated PA, the detection of more patients with PA is obligatory, and treatment success must be monitored. The investigators hypothesize that patients with primary aldosteronism have excessive Na+ storage in the muscle, which can now be quantified non-invasively using 23NaMRI. This study will be the first to systematically quantify changes in muscle Na+ stores in these patients in response to standard therapy. There is currently no established clinical diagnostic tool to detect or quantify the underlying cellular Na+/K+ redistribution physiology in patients with PA. Seeing and quantifying the Na+ non-invasively with 23NaMRI will provide a fresh "look" into the pathophysiological principles of solute and fluid homeostasis to evaluate therapy efficacy, and to improve rates of PA diagnoses with an intention to cure. This is a prospective non-randomized multi-centre study with 3 study visits ( pre-potassium treatment, pre- diagnosis and post-treatment) over a study period of 3 years. Approximately 100 participants will be recruited from hospital sites. The purpose of the study is to detect and quantify a hidden pathophysiological Na+/K+ redistribution process at the tissue level, using 23NaMRI, in an effort to provide an alternative to traditional hormone and solute diagnostics in blood and urine.