Non-Adherence Plagues Patients with High Blood Pressure

A new study published by Hypertension suggests that only 1 in 5 patients with hard-to-treat high blood pressure, who sought the help of a specialist, take their prescription drugs properly.

These results are particularly concerning because adhering to these drugs can prevent adverse cardiovascular events, such as a heart attack.

“Another twenty percent are not taking any of their blood pressure medications,” said senior study author Peter Blankestijn, MD, PhD. “People mistakenly thought to have resistant hypertension — which is high blood pressure despite taking 3 or more medications – end up seeing specialists and undergoing extra tests because we don’t understand why they are so difficult to treat.”

The authors aimed to determine if patients with resistant hypertension were able to undergo renal denervation, which is when a catheter is inserted into a blood vessel in the groin and advances into the kidney. Once the catheter reaches the artery feeding the kidney, radio waves or ultrasound destroys nerves relaying messages between the brain and the kidneys.

“There is much evidence to suggest that these nerves play a role in high blood pressure. In the 1930s and 1940s, the nerves were sometimes cut during surgical procedures. Now the nerve destruction can be done in a much less invasive way. Several devices are being studied as possible treatments for resistant hypertension,” Dr Blankestijn said. “This study, one of the first to look in detail at patient compliance, found renal denervation as therapy for resistant hypertension was not superior to usual care.”

Patients were randomized to receive renal denervation, in addition to their typical medication, and the control group was instructed to remain on their current treatment regimen of prescription drugs. Patients wore a blood pressure monitor to measure their average daytime systolic blood pressure, and blood tests were conducted to measure drug levels, according to the study.

The investigators discovered that, surprisingly, only 20% of patients were completely adherent to their treatment, while 20% were not taking any of their prescribed medications.

During the study, 31% of patients were observed to improve or reduce their medication adherence. This fluctuation in adherence could result in poor health outcomes for the patients.

After 6 months, average systolic blood pressure was observed to fall 2 mmHg more in control patients compared with those who received renal denervation, but the authors noted that it was still abnormally high in both groups.

Among patients with similar medication levels in the blood, systolic blood pressure fell 3.3mmHg among those who received the procedure.

“Adherence to medication greatly affects the ability to assess the value of another treatment, so researchers need to measure adherence and do what they can to improve it,” Dr Blankestijn said.

Patients and physicians should be aware of adherence concerns, and discuss how to properly take each medication to ensure that the proper regimen is being followed, according to the authors.

“At a minimum, be open and honest and tell your physician if you don’t want to take your pills for any reason,” Dr Blankestijn concluded. “You and your doctor can discuss options for changing the type of pill or the dose if needed. There are many effective blood pressure pills and the majority of patients with high blood pressure can be successfully treated.”