Cor Vasa 2007, 49(10):351-354 | DOI: 10.33678/cor.2007.127

Prevalence and clinical characteristics of resistant hypertension in a specialist center

Tomáš Pikus, Jiří Widimský jr., Tomáš Zelinka, Jan Rosa, Branislav Štrauch, Ondřej Petrák, Robert Holaj

Centrum pro hypertenzi, III. interní klinika, Všeobecná fakultní nemocnice a 1. lékařská fakulta Univerzity Karlovy, Praha, Česká republika

Aim of study:
To determine the prevalence and clinical characteristics of resistant hypertension in a group of patients examined in a hypertension center.

Methods:
We examined a series of 620 individuals (mean age, 55 ± 10 years) with arterial hypertension referred to our Hypertension Center over the years 2005-2006 in an effort to assess the possibility of a secondary etiology of the hypertension. During hospitalization, all patients had a thorough diagnostic assessment including determination of selected hormonal parameters, 24-hour ambulatory blood pressure monitoring, and use of imaging techniques. Resistant hypertension was defined (after ruling out secondary forms) as follows: clinical blood pressure in the physician s office of 140/90 mmHg and higher while using at least a triple combination of antihypertensive drugs including diuretics, or a self-measured blood pressure of 135/85 mmHg and higher while using at least a triple combination of antihypertensive drugs including diuretics, or a mean blood pressure, as measured by 24-hour ambulatory blood pressure monitoring, of 130/80 mmHg and higher while using at least a triple combination of antihypertensive drugs including diuretics.

Results:
Upon excluding the possibility of a secondary etiology, resistant hypertension was diagnosed in 61 individuals (a prevalence of 10%). Mean duration of hypertension was 16 ± 9 years and baseline clinical blood pressure was 188 ± 27/104 ± 18 mmHg. A normal body mass index was determined in only 15% of individuals, with the remaining patients being overweight (25%) and obese (60%). Diabetes mellitus was present in 21 patients (38%), with metabolic syndrome criteria met by 22 (40%) individuals; 84% of the patients were taking combinations of four or more antihypertensives. Mean values of serum creatinine were 93 ± 29 μmol/L, plasma renin activity 1.5 ± 1.9 ng/ml/h, and plasma aldosterone 153 ± 123 pg/ml. The incidence of cardiovascular target organ damage was as follows: carotid atherogenic lesions were documented in 59%, concentric left ventricular remodeling in 38%, and left ventricular hypertrophy in 41% of examined patients.

Conclusion:
Our study has demonstrated that resistant hypertension is not rare in clinical practice and can also be encountered in patients with combination therapy comprising antihypertensive drugs of more than five different classes. Non-responders were shown to have a high incidence of obesity, metabolic syndrome, diabetes mellitus, and target organ damage.

Keywords: Hypertension; Resistance to therapy; Prevalence; Clinical characteristics

Published: October 1, 2007  Show citation