An estimated 75 million Americans have hypertension, or high blood pressure, and 50 million take antihypertensive drugs. But in as many as 20 percent of cases, the drugs don't bring the blood pressure under control, and most doctors randomly add drug after drug in an expensive, prolonged and often unsuccessful guessing game to see what works.

A new review article in the February Journal of Clinical Hypertension by Dr. Samuel Mann reports on an approach that greatly simplifies and improves the treatment of what is called "resistant hypertension." He reports that this approach usually brings blood pressure under control more quickly and with fewer drugs and side effects. It can also help physicians supersede this trial-and-error process and more quickly get their patients the treatment they need.

"Despite the availability of many effective antihypertensive drugs, resistant hypertension is a reality for many. Treatment guidelines offer only general recommendations such as reducing sodium intake, increasing drug dosage, and adding drugs but provide clinicians with little guidance on which drugs to select," says Dr. Mann, professor of clinical medicine at Weill Cornell Medical College and a hypertension specialist at NewYork-Presbyterian Hospital/Weill Cornell Medical Center. "What we have instead is the inefficient and often unsuccessful method of doctors randomly adding drug after drug."

The Mann Algorithm

Dr. Mann's paper outlines a simplified decision tree, or algorithm, that can help physicians choose medications that can control the blood pressure in most patients with resistant hypertension. It narrows the treatment choices to either or both of just two options, using drugs that target specific mechanisms that underlie hypertension. Dr. Mann says he developed the algorithm because he believes that basing the choice of medication on the mechanisms driving an individual's hypertension enables treatment that is a better fit for each patient.

The algorithm targets three dominant mechanisms of hypertension: sodium/volume, the renin-angiotensin system (RAS), and the sympathetic nervous system (SNS). These mechanisms, alone or in combination, are the driving force of hypertension in most patients and are the target of most available antihypertensive drugs: diuretics, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, direct renin inhibitors, beta-blockers, alpha-blockers and central alpha-agonists.

Most patients with ordinary hypertension respond to widely used two-drug combinations that target blood volume (e.g., a diuretic) and the RAS (e.g., an ACE inhibitor). Dr. Mann's algorithm focuses on patients whose hypertension is resistant to these combinations. It simplifies their treatment by identifying two options that, alone or in combination, are highly likely to bring hypertension under control:

1. Strengthening the diuretic regimen, particularly in this era of high salt intake, often with the addition of a potassium-sparing diuretic such as spironolactone.

2. Addition of medications directed at SNS-mediated hypertension, often referred to as "neurogenic hypertension," usually a combination of an alpha- and beta-blocker.

"Unfortunately, neurogenic hypertension and the alpha- plus beta-blocker combination are not on the radarscope of many physicians. Yet this treatment option is very effective and can be a godsend -- particularly in patients who have not responded to drugs that target sodium/volume and the RAS, in whom one must conclude that another mechanism, likely the SNS, is at play," says Dr. Mann.

Importantly, this option is particularly effective, yet widely overlooked, in hypertension that is driven by psychological factors (mind/body hypertension). Dr. Mann has been a pioneer in delineating the role that the handling of stress and prior trauma play in understanding and treating neurogenic hypertension.

Dr. Mann says he hopes the identification of the genetic determinants of hypertension can ultimately help in individualizing the drug therapy of hypertension, but many more years of research are needed. "In the meantime, I hope my algorithm will help clinicians treat patients with resistant hypertension more efficiently and with better outcomes."

Source:
NewYork-Presbyterian Hospital/Weill Cornell Medical Center