Abstract Body: Introduction. A systematic screening of hypertensive patients for secondary arterial hypertension (SHT) is generally held to be not justified by the low prevalence of SHT but improved knowledge and diagnostic tools might change this view.

Hypothesis. To challenge the notion that the prevalence of SHT is low, we prospectively submitted consenting hypertensive patients presenting between 2017 and 2023 to a systematic search for SHT.

Methods. The systematic search for SHT entailed, besides history and full physical examination, renal Doppler ultrasound assessment, a sleep questionnaire, and measurement of serum Na⁺, K⁺, ionized Ca²⁺, plasma active renin (DRC), aldosterone concentration (PAC), the aldosterone-renin ratio (ARR), PTH, TSH, and 24-h urinary/plasma Na⁺, K⁺, Ca²⁺, phosphate, and metanephrine and normetanephrine excretion. Cure or prominent improvement of hypertension after target treatment was used to confirm SHT.

Results. In 494 consecutive patients (median age 62 years, 50% women) who completed the work-up, we found that 11.5% of these patients had isolated systolic hypertension. The overall prevalence of SHT among those with systo-diastolic HT was 72.3%: 25.5% had primary aldosteronism; 13.4% obstructive sleep apnea, 7.9% hypothyroidism, 6.5% renovascular hypertension and 19.0% rarer causes of SHT. Of all patients, only 14% were referred by their general practitioner or other specialists and 85% were self-presenting.

Conclusions. Only a small minority of consecutive hypertensive patients seen in a specialized center were referred by their doctors, thus calling for implementation of broad strategies to increase the awareness of SHT. The fact that a systematic screening showed that SHT is far more common than currently believed supports this conclusion.