Resistant hypertension: an overview.
OBJECTIVE
To review the factors contributing to treatment resistance in hypertensive patients and assess the evidence from therapeutic trials in these patients.


METHODS
A MEDLINE search using the words 'resistant hypertension', 'refractory hypertension' and 'treatment resistance, hypertension' was carried out to identify relevant articles. The bibliographies of articles were used to screen for other relevant articles. All available English-language articles on the epidemiology, prognosis and management of hypertension resistant to standard treatment were reviewed.


RESULTS
Resistant hypertension is an important public health problem and a common reason for referral of patients to specialized hypertension clinics. Patients with uncontrolled hypertension are at increased risk of stroke, myocardial infarction, congestive heart failure and renal failure. Many factors may play a role in the development of resistant hypertension, including misdiagnosis (pseudoresistance), noncompliance, occult secondary causes for hypertension, volume overload, obesity, cigarette smoking, excess alcohol intake, sleep apnea, interfering medications and suboptimal combinations of antihypertensives. Only beta-blockers and thiazide diuretics have been demonstrated to reduce cardiovascular morbidity and mortality in hypertension. The trials evaluating third-line agents in patients with resistant hypertension have demonstrated additional blood pressure lowering with all classes of agents, and the randomized controlled trials have not demonstrated any statistically significant differences between the agents in either efficacy or tolerability.


CONCLUSIONS
Evaluation of the patient with resistant hypertension should include 24 h ambulatory blood pressure monitoring and an extensive search for hypertensive end organ damage. Contributing factors should be sought and stepped care should still form the basis for treatment decisions. The choice of third-line agent should be dictated by the patient's renin profile, current medication and any concomitant diseases.
McAlister
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FA
Division of General Internal Medicine, University of Alberta Hospital, Edmonton. finlay@ceu.uottawa.ca
Lewanczuk
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RZ
Teo
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KK
D000319:Adrenergic beta-Antagonists / Q000627:therapeutic use; D000959:Antihypertensive Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D002740:Chlorothiazide / Q000627:therapeutic use; D004351:Drug Resistance; D005260:Female; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology; D006974:Hypertension, Malignant / Q000517:prevention & control; D008297:Male; D009765:Obesity / Q000150:complications; D009864:Ontario / Q000453:epidemiology; D012307:Risk Factors; D012907:Smoking / Q000009:adverse effects
D000319:Adrenergic beta-Antagonists; D000959:Antihypertensive Agents; D002740:Chlorothiazide