RESISTANT HYPERTENSION - AN OVERVIEW

OBJECTIVE: To review the factors contributing to treatment resistance in hypertensive patients and assess the evidence from therapeutic tria ls in these patients. DESIGN: A MEDLINE search using the words 'resist ant hypertension,' refractory hypertension' and 'treatment resistance, hypertension' was carried out to identify relevant articles. The bibl iographies of articles were used to screen for other relevant articles . All available English-language articles on the epidemiology, prognos is and management of hypertension resistant to standard treatment were reviewed. RESULTS: Resistant hypertension is an important public heal th 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 fail ure 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 overl oad, obesity, cigarette smoking, excess alcohol intake, sleep apnea, i nterfering medications and suboptimal combinations of antihypertensive s. Only beta-blockers and thiazide diuretics have been demonstrated to reduce cardiovascular morbidity and mortality in hypertension. The tr ials evaluating third-line agents in patients with resistant hypertens ion have demonstrated additional blood pressure lowering with all clas ses of agents, and the randomized controlled trials have not demonstra ted any statistically significant differences between the agents in ei ther efficacy or tolerability. CONCLUSIONS: Evaluation of the patient with resistant hypertension should include 24 h ambulatory blood press ure monitoring and an extensive search for hypertensive end organ dama ge. Contributing factors should be sought and stepped care should stil l form the basis for treatment decisions. The choice of third-line age nt should be dictated by the patient's renin profile, current medicati on and any concomitant diseases.