Resistant hypertension increases the risk of stroke by 35 percent in women and 20 percent in elderly patients, say researchers.

For the study, the researchers examined the medical records of 111,986 Taiwanese patients from 2000 to 2011. The team noted that around 16,402 (14.6 percent) patients had resistant hypertension.

Researchers analyzed the risk of major adverse cardiovascular events (MACE) in patients with resistant hypertension and non-resistant hypertension. They found that 11,856 patients had MACE in the average 7.1 year follow-up period.

The study revealed that people with resistant hyper-tension had a 17 percent higher risk of MACE compared to those with non-resistant hypertension.

"Patients with hypertension that does not respond to conventional drug treatments, called resistant hypertension, are at a higher risk of cardiovascular morbidity and mortality," Dr Kuo-Yang Wang from Taiwan said in a press release.

According to Dr. Wang, the findings indicate that gender and age should be added to the risk stratification of resistant hypertension to enable appropriate treatment decisions.

"Our study shows that patients with resistant hypertension have higher risks for cardiovascular events than those with non-resistant hypertension. The elevated risks mainly contribute to increasing stroke events, especially ischaemic stroke."

Upon further analysis, researchers found that resistant hypertension worsened the risk of stroke in females by 35 percent and in elderly patients by 20 percent. However, no major influence was noted in young or male patients.

"While this is the first study to explore the relationship between gender, age, and MACE in patients with resistant hypertension, further research is needed to confirm this relationship and to identify the exact mechanisms involved," Dr Wang said.