Estimate the frequency of true resistant hypertension among uncontrolled hypertensive patients referred to a tertiary health care center.Design and method:
The study was prospective and observational. We screened all hypertensive patients, 18 years old or more treated for at least 12 months and referred for uncontrolled hypertension to Tizi-ouzou teaching hospital (hypertension unit). Resistant hypertension was defined as an office blood pressure (OBP) superior or equal to 140/90 mmHg, and 24-hour ambulatory blood pressure (ABP) superior or equal to 130/80 mmHg, despite 3 drugs including a diuretic, a renin angiotensin system blocker and a calcium channel blocker at optimal doses, for at least 4 weeks.Results:
A total of 2367 patients were included between January 2013 and April 2015. Of these, 843 had an inadequate treatment regimen (426: less than 3 drugs; 238: suboptimal doses; 179: inappropriate combinations), 364 a poor adherence to prescribed antihypertensive treatment and 202 a white coat effect. Among the 958 remaining subjects, 281 had an excessive salt intake (superior to 15 g per a day, assessed by 24-hour urine sodium), 36 had interfering medications or substances consumption, and secondary causes were documented in 468 patients (Primary aldosteronism: 204, Obstructive sleep apnea:151, Renal artery stenosis:83, other causes: 30). Finally, only 173 subjects of the initial population had a true resistant hypertension, corresponding to a prevalence of 7.3% (CI 95%: 6.3%–8.3%). The mean OBP and 24-hour ABP of these patients were 159.8 ± 22.1/ 94.4 ± 14.7 and 149.4 ± 15.5/ 89.7 ± 12.7 mmHg, respectively. Their clinical characteristics were: mean age (59.7 ± 11.6); women (53.2%); diabetes (27.2%); dyslipidemia (46.2%); smoking (39.3%); mean BMI (30.6 ± 4.7); median GFRe (63.2 ml/min/1.73m2); prior major cardiovascular event (21.4%). After treatment intensification (spironolactone: 51.4%, beta-blockers:26.6%, spironolactone plus beta-blocker:17.9%, spironolactone plus beta-blocker plus central antihypertensive agent: 4.1%), the proportion of controlled patients at 3 months was 64.7% as assessed by ABP measurement.Conclusions:
Most of the patients with seemingly resistant hypertension can reach blood pressure target provided they undergo thorough work up and care by a multidisciplinary team.