Prevalence and clinical profile of refractory hypertension in a large cohort of patients with resistant hypertension

Resistant hypertension (RH) is defined as above-goal elevated blood pressure (BP) in a patient despite the concurrent use of 3 antihypertensive drug classes, commonly including a long-acting calcium channel blocker, a blocker of the renin-angiotensin system (angiotensin-converting enzyme inhibitor or angiotensin receptor blocker), and a diuretic. The antihypertensive drugs should be administered at maximum or maximally tolerated daily doses. RH also includes patients whose BP achieves target values on ≥4 antihypertensive medications. The diagnosis of RH requires assurance of antihypertensive medication adherence and exclusion of the "white-coat effect" (office BP above goal but out-of-office BP at or below target). The importance of RH is underscored by the associated risk of adverse outcomes compared with non-RH. This article is an updated American Heart Association scientific statement on the detection, evaluation, and management of RH. Once antihypertensive medication adherence is confirmed and out-of-office BP recordings exclude a white-coat effect, evaluation includes identification of contributing lifestyle issues, detection of drugs interfering with antihypertensive medication effectiveness, screening for secondary hypertension, and assessment of target organ damage. Management of RH includes maximization of lifestyle interventions, use of long-acting thiazide-like diuretics (chlorthalidone or indapamide), addition of a mineralocorticoid receptor antagonist (spironolactone or eplerenone), and, if BP remains elevated, stepwise addition of antihypertensive drugs with complementary mechanisms of action to lower BP. If BP remains uncontrolled, referral to a hypertension specialist is advised.

We aimed to estimate the prevalence of resistant hypertension through both office and ambulatory blood pressure monitoring in a large cohort of treated hypertensive patients from the Spanish Ambulatory Blood Pressure Monitoring Registry. In addition, we also compared clinical features of patients with true or white-coat-resistant hypertension. In December 2009, we identified 68 045 treated patients with complete information for this analysis. Among them, 8295 (12.2% of the database) had resistant hypertension (office blood pressure ≥140 and/or 90 mm Hg while being treated with ≥3 antihypertensive drugs, 1 of them being a diuretic). After ambulatory blood pressure monitoring, 62.5% of patients were classified as true resistant hypertensives, the remaining 37.5% having white-coat resistance. The former group was younger, more frequently men, with a longer duration of hypertension and a worse cardiovascular risk profile. The group included larger proportions of smokers, diabetics, target organ damage (including left ventricular hypertrophy, impaired renal function, and microalbuminuria), and documented cardiovascular disease. Moreover, true resistant hypertensives exhibited in a greater proportion a riser pattern (22% versus 18%; P<0.001). In conclusion, this study first reports the prevalence of resistant hypertension in a large cohort of patients in usual daily practice. Resistant hypertension is present in 12% of the treated hypertensive population, but among them more than one third have normal ambulatory blood pressure. A worse risk profile is associated with true resistant hypertension, but this association is weak, thus making it necessary to assess ambulatory blood pressure monitoring for a correct diagnosis and management.

The aim of this study was to validate the Omron HEM-907 blood pressure (BP) measuring device according to the international validation protocol. The international validation protocol is divided into two phases: the first phase is performed on 15 selected subjects and if the device passes this phase, 18 more subjects are selected making a total number of 33 subjects on which the final validation is performed. For each subject, BP measurements were performed simultaneously by two trained observers using mercury sphygmomanometers alternately with the Omron HEM-907 device. In all, 99 measurements were obtained for comparison. The difference between the BP value given by the device and that obtained by the two observers (mean of the two observers) was calculated for each measure. The difference between the two observers was -1 +/- 2 mmHg for the systolic BP (SBP) and for the diastolic BP (DBP). The Omron HEM-907 passed the first phase of the validation process. For the second phase, the average differences between the device and mercury sphygmomanometer readings were -1 +/- 7 and -5 +/- 6 mmHg for SBP and DBP respectively. Readings for the HEM-907 device differed by less than 5 mmHg for 61 of the systolic readings and 52 of the diastolic readings; by less than 10 mmHg for 85 of the systolic readings and 85 of the diastolic readings; and by less than 15 mmHg for 94 of the systolic readings and 96 of the diastolic readings. The Omron HEM-907 device passes the two phases of the international validation protocol. Copyright 2002 Lippincott Williams & Wilkins