Resistant hypertension

I was invited this week to give a couple of lectures during the Resistant Hypertension Conference held in Singapore, and I share the consensus of all the members of the faculty who are getting alarmed at the increasing prevalence of resistant or difficult-to-treat high blood pressure (BP).

Resistant hypertension is defined as high BP that is not adequately controlled to less than 140/90 mmHg with three antihypertensive drugs given at optimal dosages. Ideally, a diuretic, which gets rid of the excess salt one takes in, should be included in the drug regimen.

Some hypertensive patients may require four  to six drugs to control the BP and that’s called controlled resistant hypertension. These patients should be closely monitored, too, although their BP may be apparently controlled.

We don’t really have good data in the Asia-Pacific region on how prevalent this problem is. But many of the experts present at the conference believe that it’s a more significant problem in this region than in the United States and Europe because patient adherence to long-term treatment is a major issue here.

Many Filipino hypertensive patients, for example, usually don’t take their maintenance medicines religiously. Some may only take them when they have symptoms—a highly unreliable gauge for determining if one has high BP or not. In fact, many symptomless hypertensive patients who succumb to a heart attack or stroke have never complained of any symptom previously.

Noncompliant patients

Strictly speaking, these noncompliant patients should not be labeled as having resistant hypertension because they have not been taking their medicines as instructed. Many would therefore call these patients as having pseudoresistant hypertension. Still, these patients have to be identified because they stand a high risk of developing serious complications. And they won’t even know what hit them.

Many of these patients with resistant hypertension may have a secondary cause making the BP shoot up beyond the roof. These secondary causes could be kidney problems, tumors in the adrenal glands, and inborn abnormalities in the blood vessels which make them constricted. However, there are drugs which can increase the BP and make it difficult to control. These include contraceptive drugs, anti-arthritis drugs, prohibited or the so-called “recreational drugs,” cold medicines, reducing pills and even herbals like the ephedra, also known as ma huang.

Some practical cases were also presented during the conference, discussing patients who took salt excessively or drank more than two shots of liquor every day. Their BPs were resistant to treatment at the start. But with the elimination of these lifestyle factors, there was a better response of the BP to the drugs prescribed.

Obstructive sleep apnea (OSA), which is fairly common in those who snore, is also a relatively common cause of uncontrolled high BP. If you notice your spouse or partner snoring loudly almost the entire night and stops breathing for several seconds in between, he or she might have OSA. He or she will likely be hypertensive, too. Overweight, OSA and hypertension always go together in many instances.

There is a prevailing misconception that if one snores, that means he or she is in  deep and restful sleep. Actually, the opposite is true. The quality of the sleep of patients with OSA is poor, so during the day, they feel sleepy; they can fall asleep easily when you’re talking to them or even while they’re driving.

Sleep studies

There are now sleep studies in many medical centers. Also, a device called CPAP (continuous positive airway pressure) can dramatically reduce their snoring and the OSA. So, even the spouse will love this device. I recall a wife once blaming me for not having recommended it earlier. “For the longest time, I had to endure the loud snoring of my husband, when all that was needed was this simple device,” she said.

During the conference, the participants learned of new clinical data demonstrating the effectiveness of a new technology to treat resistant hypertension, and hopefully, this could be made available to our local patients, too. It’s called renal nerve denervation because the nerves which supply the kidneys are sort of deactivated by a device through a catheter inserted either from the groin or the wrist to the kidney arteries. The nerves in the arterial wall are “denerved” or killed using ultrasound or radiofrequency energy delivered through the catheter.

The procedure is not really complicated and  offers a big opportunity to treat many resistant hypertensive cases and save patients from the life-threatening complications of uncontrolled hypertension. I figure that the cost can be a major constraint for this procedure, but it shouldn’t cost more than the stents that some patients get when their arteries are clogged. And severely elevated, uncontrollable hypertension could be as equally serious as the case of patients with clogged arteries.

Incidentally, the Philippine Society of Hypertension (PSH) and the Philippine Lipid and Atherosclerosis Society (PLAS) will be hosting the next Asian Pacific Congress of Hypertension on Feb. 12-15, 2014, at the Radisson Blu Hotel in Cebu City. More than 2,000 foreign and local experts on hypertension management are expected to attend this international convention to share and learn what’s new in the battle to treat hypertension.

Big congress

The PSH and PLAS are collaborating with the Philippine College of Physicians, the Philippine Heart Association, the Philippine Medical Association and the Department of Health for this big congress.

The organizers are also heartened by the all-out support of Cebu Gov. Hilario Davide III, Mayor Michael Rama, and the Department of Tourism. The Philippine National Police also committed to assign more policemen in the vicinity of the congress venue and other hotels being occupied by the delegates to ensure their safety.

We look forward to a very successful congress that can highlight our local accomplishments in researches and programs that can help stem the tide of high blood pressure in our country.