Circulation research
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Circulation research · Mar 2015
ReviewHypertension: renin-angiotensin-aldosterone system alterations.
Blockers of the renin-angiotensin-aldosterone system (RAAS), that is, renin inhibitors, angiotensin (Ang)-converting enzyme (ACE) inhibitors, Ang II type 1 receptor antagonists, and mineralocorticoid receptor antagonists, are a cornerstone in the treatment of hypertension. How exactly they exert their effect, in particular in patients with low circulating RAAS activity, also taking into consideration the so-called Ang II/aldosterone escape that often occurs after initial blockade, is still incompletely understood. Multiple studies have tried to find parameters that predict the response to RAAS blockade, allowing a personalized treatment approach. ⋯ Are all blockers equal? Does optimal blockade imply maximum RAAS blockade, for example, by combining ≥2 RAAS blockers or by simply increasing the dose of 1 blocker? Exciting recent investigations reveal a range of unanticipated extrarenal effects of aldosterone, as well as a detailed insight in the genetic causes of primary aldosteronism, and mineralocorticoid receptor blockers have now become an important treatment option for resistant hypertension. Finally, apart from the deleterious ACE-Ang II-Ang II type 1 receptor arm, animal studies support the existence of protective aminopeptidase A-Ang III-Ang II type 2 receptor and ACE2-Ang-(1 to 7)-Mas receptor arms, paving the way for multiple new treatment options. This review provides an update about all these aspects, critically discussing the many controversies and allowing the reader to obtain a full understanding of what we currently know about RAAS alterations in hypertension.
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Circulation research · Mar 2015
ReviewRandomized controlled trials of blood pressure lowering in hypertension: a critical reappraisal.
Sixty-eight blood pressure (BP)-lowering randomized controlled trials (defined as randomized controlled trials comparing active treatment with placebo, or less active treatment, achieving a BP difference, performed between 1966 and end 2013 in cohorts with ≥ 40% hypertensive patients, and exclusive of trials in acute myocardial infarction, heart failure, acute stroke, and dialysis) were identified and meta-analyzed grouping the randomized controlled trials on the basis of clinically relevant questions: (1) does BP lowering reduce all types of cardiovascular outcome? (2) Is prevention of all outcomes proportional to the extent of systolic, diastolic, and pulse BP? (3) Have all classes of BP-lowering drugs been shown capable of reducing all types of cardiovascular outcome? (4) Is BP lowering beneficial when intervention is initiated at any grade (or stage) of hypertension? (5) Do BP-lowering randomized controlled trials provide evidence about systolic BP and diastolic BP targets of treatment? (6) Should BP-lowering treatment be preferentially addressed to patients in higher risk categories promising larger absolute treatment benefits? The results of these meta-analyses provide further support to current hypertension treatment guidelines by showing that BP lowering can significantly reduce major cardiovascular outcomes largely independent of the agents used, significant risk reduction is found at all hypertension grades (stages), and when systolic BP is lowered below a cut off of 140 mm Hg with some further reduction limited to stroke at systolic BP values just <130 mm Hg. Absolute risk reduction progressively increases higher is total cardiovascular risk, but this greater benefit is associated with a progressively higher residual risk, ie, higher treatment failures.
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Circulation research · Mar 2015
ReviewThe epidemiology of blood pressure and its worldwide management.
Despite the vast amount of evidence on the benefits of blood pressure lowering accumulated to date, elevated blood pressure is still the leading risk factor for disease and disability worldwide. The purpose of this review is to summarize the epidemiological evidence underpinning the association between blood pressure and a range of conditions. ⋯ Evidence for and against the existence of a J-shaped curve association between blood pressure and cardiovascular risk, and differences in the predictive power of systolic, diastolic, and pulse pressure, are described. In addition, global and regional trends in blood pressure levels and management of hypertension are reviewed.
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Sodium is an essential nutrient. Increasing sodium intake is associated with increasing blood pressure, whereas low sodium intake results in increased renin and aldosterone levels. Randomized controlled trials have reported reductions in blood pressure with reductions in sodium intake, to levels of sodium intake <1.5 g/d, and form the evidentiary basis for current population-wide guidelines recommending low sodium intake. ⋯ The increased risk of cardiovascular events associated with higher sodium intake (>5 g/d) is most prominent in those with hypertension. A major deficit in the field is the absence of large randomized controlled trials to provide definitive evidence on optimal sodium intake for preventing cardiovascular events. Pending such trials, current evidence would suggest a recommendation for moderate sodium intake in the general population (3-5 g/d), with targeting the lower end of the moderate range among those with hypertension.
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Hypertension is the most common modifiable risk factor for cardiovascular disease and death, and lowering blood pressure with antihypertensive drugs reduces target organ damage and prevents cardiovascular disease outcomes. Despite a plethora of available treatment options, a substantial portion of the hypertensive population has uncontrolled blood pressure. The unmet need of controlling blood pressure in this population may be addressed, in part, by developing new drugs and devices/procedures to treat hypertension and its comorbidities. ⋯ Renal denervation is also being evaluated for treatment of various comorbidities, eg, chronic heart failure, cardiac arrhythmias and chronic renal failure. Novel interventional approaches in early development include carotid body ablation and arteriovenous fistula placement. Importantly, none of these novel drug or device treatments has been shown to prevent cardiovascular disease outcomes or death in hypertensive patients.