Diagnostic yield of hypertension evaluation in a nephrology day hospital

Secondary hypertension (HTN) accounts for 5–10% of HTN. The actual diagnostic yield of a comprehensive etiological work-up in nephrology-specialized centers remains poorly documented.

We conducted a single-center retrospective study including all patients evaluated in the day hospital program of the ESH-accredited Hypertension and Nephrology Unit at Rouen University Hospital for suspected secondary HTN, between 2018 and 2019. The standardized protocol combined clinical assessment, laboratory testing, imaging, and multidisciplinary discussion.

One hundred patients were included. The mean age was 46.8±14.1 years; 58% were women. The main referral reasons were young age (41%), severe HTN (30%), hypokalemia (23%), and resistant HTN (22%). A secondary cause was identified in 60% of cases: primary aldosteronism (20%), kidney disease (16%), obstructive sleep apnea (12%), obesity (12%), drug-induced HTN (9%), secondary hyperaldosteronism (5%), and pseudohyperaldosteronism (3%). Essential HTN accounted for 48% of cases. Multiple diagnoses were present in 21% of cases. Hypokalemia as a motive was associated with primary aldosteronism (48% vs. 10–17% for other motives, p=0.01). Antihypertensive treatment was modified in 72% of patients with secondary HTN vs. 65% with essential HTN (p=0.53), in accordance with current guidelines at that time. An interventional or surgical treatment was performed in 6% of cases, and 83% of patients with sleep apnea were treated with continuous positive airway pressure.

In a nephrology-specialized ESH-accredited center, the diagnostic yield of secondary hypertension evaluation is high, with significant therapeutic implications. This supports the role of specialized nephrology centers in hypertension work-up.