Clinical Features of 8295 Patients With Resistant Hypertension Classified on the Basis of Ambulatory Blood Pressure Monitoring

Abstract

Abstract-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 Ն140 and/or 90 mm Hg while being treated with Ն3 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%; PϽ0.001). 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. (Hypertension. 2011;57:898-902.) • Online Data Supplement Key Words: resistant hypertension Ⅲ ambulatory blood pressure monitoring Ⅲ circadian pattern Ⅲ cardiovascular risk R esistant hypertension (RH) is defined as office blood pressure (BP) that remains above goal despite the concurrent use of 3 antihypertensive agents, at full doses, one of them being a diuretic. Although the prevalence of RH largely depends on the setting explored, this condition is of clinical importance, because it is associated with an impaired prognosis. 1 The definition of RH is based on office measurements. However, the use of ambulatory BP monitoring (ABPM) has allowed for the recognition of the white-coat effect as being responsible for a proportion of resistant hypertensive patients. It is estimated that approximately one third of patients with suspected RH indeed have white-coat or isolated office RH, showing normal daytime or 24-hour ABPM values. [2][3][4] Elevated ABPM values in patients with RH are associated with a higher prevalence of target organ damage 4,5 and increased incidence of future cardiovascular events. 6 -8 However, these data come from relatively small populations attended in single referral units, whereas there is lack of data coming from large hypertensive populations representi...

Prevalence and Clinical Characteristics of Refractory Hypertension

“…Although its prevalence was considerably lower than that of RH,2 it is surprising that those patients were still receiving 5 or more drugs based only on clinic BP, without considering ABPM in earlier steps of management. A recent report10 has found that normal ABPM of RfH was present only in 2 out of 31 patients with RfH.…”

“…The methodology of office BP measurements and 24‐hour ABPM has been previously described by our group 2, 4, 11, 12. Briefly, BP was measured at the office with a calibrated mercury sphygmomanometer or a validated oscillometric device, after 5 minutes rest in a sitting position.…”

“…Several studies have observed a prevalence of around 12% to 14% of treated hypertensives 2, 3. Compared with subjects with controlled hypertension with 3 or less antihypertensive drugs, patients with RH more frequently have target organ damage4, 5 and a higher incidence of cardiovascular events 6.…”

Assessment and management of resistant hypertension

“…Obesity (especially visceral adiposity) and obstructive sleep apnea are the two most prevalent factors, the former found in 50% of people with resistant hypertension 18 and the latter in 64%-83%. 19,20 Concurrent use of certain medications or substances can also lead to resistance (Box 2).…”

“…White-coat effect (present to some extent in up to 40% of patients with apparently resistant hypertension 18 ), inaccurate measurement techniques, nonadherence to treatment and a suboptimal medication regimen are common contributors. 1 Use of 24-hour ambulatory monitoring or self-monitoring at home to document a normal out-of-office blood pressure level rules out white-coat effect.…”