Saturday, November 20, 2010
blood pressure
Summary and Comment
New Perspectives on an Old Problem: Tailoring Treatment for Hypertension
Three studies lay the groundwork for moving beyond a "cookbook" approach to drug therapy.
Despite the availability of several antihypertensive drug classes and numerous individual agents, hypertension remains poorly controlled in many patients. Improving control rates will require tailoring of therapy to individual patient factors. In a recent issue of the American Journal of Hypertension, three studies address the heterogeneity of response to various antihypertensive drugs, and two editorialists use the findings to propose novel treatment paradigms.
Two studies highlight inter-individual responses to treatment. Turner and colleagues found that measures of plasma renin activity (PRA) predicted patient responses to atenolol or hydrochlorothiazide, both as monotherapy and as add-on therapy, independently of patient age, race, and pretreatment blood pressure (BP). Alderman and colleagues assessed the frequency of paradoxical pressor responses (BP increases ≥10 mm Hg) in patients during initial monotherapy with various antihypertensive drugs. Patients were stratified by tertile of baseline PRA. Pressor responses occurred with all drug classes. The likelihood of a pressor response was significantly higher with an angiotensin-converting enzyme (ACE) inhibitor or beta-blocker than with a diuretic or calcium-channel blocker, but only in patients in the low and middle PRA tertiles.
In a third study, researchers compared responses of white, black, and south Asian ASCOT participants randomized to initial therapy with atenolol or amlodipine; if needed, patients subsequently received a thiazide diuretic (added to atenolol) or perindopril (added to amlodipine). Atenolol monotherapy was significantly less effective in blacks than in whites and south Asians. The addition of perindopril to amlodipine was also significantly less effective in blacks than in whites and south Asians, whereas the addition of a diuretic to atenolol was not associated with any significant difference in response among the three groups.
In separate editorials, Brown and Furberg outlined different strategies for individualizing the care of patients with hypertension. Brown's approach begins by assessing the individual's probable location on the spectrum of hypertension pathophysiology (volume overload to vasoconstriction), whereas Furberg's approach begins by categorizing the hypertension as one of four types, based largely on PRA measurement. For a more detailed description of these two strategies, see JW Cardiol Nov 3 2010.
Comment: Current treatment guidelines make no real distinction between different types of hypertension pathophysiology. This "one size fits all" approach to hypertension therapy probably leads to an overuse of drugs and has been associated with poor outcomes. By sharpening our focus on the clinical predictors of response to various drugs, the present studies bring us closer to tailored approaches to hypertension management. The algorithms proposed by editorialists are intriguing, but we cannot know whether they will improve control rates — and, more important, patient outcomes — without careful clinical testing.
— JoAnne M. Foody, MD
Published in Journal Watch Cardiology November 3, 2010
New Perspectives on an Old Problem: Tailoring Treatment for Hypertension
Three studies lay the groundwork for moving beyond a "cookbook" approach to drug therapy.
Despite the availability of several antihypertensive drug classes and numerous individual agents, hypertension remains poorly controlled in many patients. Improving control rates will require tailoring of therapy to individual patient factors. In a recent issue of the American Journal of Hypertension, three studies address the heterogeneity of response to various antihypertensive drugs, and two editorialists use the findings to propose novel treatment paradigms.
Two studies highlight inter-individual responses to treatment. Turner and colleagues found that measures of plasma renin activity (PRA) predicted patient responses to atenolol or hydrochlorothiazide, both as monotherapy and as add-on therapy, independently of patient age, race, and pretreatment blood pressure (BP). Alderman and colleagues assessed the frequency of paradoxical pressor responses (BP increases ≥10 mm Hg) in patients during initial monotherapy with various antihypertensive drugs. Patients were stratified by tertile of baseline PRA. Pressor responses occurred with all drug classes. The likelihood of a pressor response was significantly higher with an angiotensin-converting enzyme (ACE) inhibitor or beta-blocker than with a diuretic or calcium-channel blocker, but only in patients in the low and middle PRA tertiles.
In a third study, researchers compared responses of white, black, and south Asian ASCOT participants randomized to initial therapy with atenolol or amlodipine; if needed, patients subsequently received a thiazide diuretic (added to atenolol) or perindopril (added to amlodipine). Atenolol monotherapy was significantly less effective in blacks than in whites and south Asians. The addition of perindopril to amlodipine was also significantly less effective in blacks than in whites and south Asians, whereas the addition of a diuretic to atenolol was not associated with any significant difference in response among the three groups.
In separate editorials, Brown and Furberg outlined different strategies for individualizing the care of patients with hypertension. Brown's approach begins by assessing the individual's probable location on the spectrum of hypertension pathophysiology (volume overload to vasoconstriction), whereas Furberg's approach begins by categorizing the hypertension as one of four types, based largely on PRA measurement. For a more detailed description of these two strategies, see JW Cardiol Nov 3 2010.
Comment: Current treatment guidelines make no real distinction between different types of hypertension pathophysiology. This "one size fits all" approach to hypertension therapy probably leads to an overuse of drugs and has been associated with poor outcomes. By sharpening our focus on the clinical predictors of response to various drugs, the present studies bring us closer to tailored approaches to hypertension management. The algorithms proposed by editorialists are intriguing, but we cannot know whether they will improve control rates — and, more important, patient outcomes — without careful clinical testing.
— JoAnne M. Foody, MD
Published in Journal Watch Cardiology November 3, 2010
# posted by roodbont @ 8:20 AM 
