“Hypertension is one of the most important risk factors for cardiovascular disease,” said Kuo-Yang Wang, from the Taichung Veterans General Hospital in Taiwan. “Patients with hypertension who do not respond to conventional drug treatments [have] resistant hypertension [and] are at even higher risk of cardiovascular morbidity and mortality.
“Little is known about the prognosis of resistant hypertension in the Asian population,” he continued. “Our study compared the risk of all-cause mortality, acute coronary syndrome, and stroke between patients with resistant hypertension and nonresistant hypertension. We aimed to discover the impact of resistant hypertension on Taiwanese patients and to ascertain whether patient characteristics influence the association between resistant hypertension and adverse outcomes.”
Patients with hypertension age 45 and older were identified from the National Health Insurance Research Database. Medical records of 111,986 patients from 2000 to 2011 were reviewed for this study. A total of 16,402 (14.6%) patients had resistant hypertension, which the researchers defined as continuously concomitant use of three or more antihypertensive medications, including a diuretic, for two years or longer. The risk of major adverse cardiovascular events (MACE, a composite of all-cause mortality, acute coronary syndrome, and stroke) in patients with resistant hypertension and nonresistant hypertension was analyzed.
The researchers found that 11,856 patients had MACE in the average 7.1-year follow-up period. Patients with resistant hypertension had a 17% increased risk of MACE, compared with those with nonresistant hypertension. When the researchers analyzed the risk of different types of cardiovascular events separately, they found that, compared with patients with nonresistant hypertension, patients with resistant hypertension had a 17% increased risk of stroke and a 34% increased risk of ischemic stroke but no increased risk of all-cause mortality or acute coronary syndrome.
“Our study shows that patients with resistant hypertension have higher risks for cardiovascular events than those with nonresistant hypertension,” said Dr. Wang. “The elevated risks mainly contribute to increasing stroke events, especially ischemic stroke.”
Subgroup analysis showed that resistant hypertension increased the risks of stroke in females by 35% and in elderly patients by 20%. No significant influence was noted in young or male patients, however.
“Our finding that resistant hypertension increased the risks of stroke in female and elderly patients, but not in young or male patients, could be because risk factors for cerebral atherosclerosis may differ between genders,” said Dr. Wang. “Previous studies have shown that hypertension was the most important risk factor for females to develop cerebral atherosclerosis, compared to diabetes and hypercholesterolemia for males.
“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. The clinical diagnosis of resistant hypertension should be combined with patient gender and age to provide a more accurate prediction of the risk of stroke. Clinicians can then target treatments at patients with the highest risk,” concluded Dr. Wang.
Fruit Consumption Reduces CVD Risk by as Much as 40%
Daily fruit consumption decreases the risk of cardiovascular disease (CVD) by as much as 40%, researchers reported. The findings from the seven-year follow-up study of nearly 500,000 people in the China Kadoorie Biobank indicate that the more fruit people eat, the more their risk of CVD declines.
“CVD, including ischemic heart disease (IHD) and stroke, is the leading cause of death worldwide. Improving diet and lifestyle is critical for CVD risk reduction in the general population, but the large majority of this evidence has come from Western countries and hardly any from China,” said Huaidong Du, MD, of the Clinical Trial Service Unit and Epidemiological Studies Unit at the University of Oxford in the United Kingdom.
“China has a different pattern of CVD, with stroke as the main cause, compared to Western countries where IHD is more prevalent,” she added. “Previous studies have combined ischemic and hemorrhagic stroke, probably due to the limited number of stroke cases in their datasets. Given their different physiology and risk factors, we have conducted the first large prospective study on the association of fruit with subtypes of stroke in Chinese adults from both rural and urban areas.”
The current study included 451,681 participants with no history of CVD who were not taking antihypertensive treatment at baseline. Participants were selected from the China Kadoorie Biobank, which included people in 10 areas of China, including five rural and five urban sites. Habitual consumption of fruit was recorded at baseline according to five categories: never, monthly, one to three days per week, four to six days per week, and daily.