Duration of Hypertension as a Key Predictor of Stroke Risk

The risk of incident stroke increases as the number of years living with hypertension increases, regardless of use of antihypertensive medications, according to findings from the REGARDS (Reasons for Geographic and Racial Differences in Stroke) cohort study published in the journal Stroke.1 The longer the duration of hypertension, the more classes of antihypertensive medications patients needed to take.

In this study, 27,310 participants in the US from the REGARDS cohort study, enrolled between 2003 and 2007, who were stroke-free at baseline were followed for a median of 12.4 years to assess incident stroke events. Participants were divided into four groups according to the duration of diagnosed hypertension: normotensive (0 years), ≤5 years, 6–20 years, and ≥21 years. The study evaluated baseline systolic BP, the number of antihypertensive medication classes used, and the risk of stroke across these groups, while adjusting for demographics, cerebrovascular risk factors, systolic BP, and use of antihypertensives where applicable.

Out of 30,239 study participants, 27,310 were included in the analysis; their average age was 65 years and 45% of them were male. Over a median follow-up of 12.4 years, 1763 incident stroke events occurred.

Participants who had hypertension for a duration of 21 years or more were taking 2.28 classes of antihypertensive medications on average compared to 1.68 classes of antihypertensive medications for those who had had hypertension for five years or less. Those who had hypertension for 6–20 years were taking 2.04 classes of antihypertensive drugs.

The adjusted mean systolic BP increased with longer durations of recognized hypertension: 123.9 mm Hg for 0 years, 129.7 mm Hg for ≤5 years, 131.7 mm Hg for 6–20 years, and 132.6 mm Hg for 21+ years.

Participants with hypertension for up to five years had a 31% higher likelihood of having a stroke compared to those without hypertension with hazard ratio (HR) of 1.31. Those with hypertension for six to 20 years faced a 50% increased risk (HR 1.50), while participants with more than 20 years of hypertension were 67% more likely to experience a stroke than participants with normal blood pressure (HR 1.67).

Stroke can be a disabling condition with adverse impact on quality of life. These findings show that prolonged hypertension is the key factor contributing to the enhanced stroke risk. Hence, these findings further highlight the urgency of identifying and addressing high BP early, before hypertension sets in. The American Heart Association (AHA) recommends following a healthy diet, avoiding or limiting alcohol consumption, maintaining a healthy body weight, managing stress, staying physically active, quitting smoking, and taking medications when necessary.

Reference

1.   Howard G, et al. Association of duration of recognized hypertension and stroke risk: The REGARDS study. Stroke. 2024 Dec 9. doi: 10.1161/STROKEAHA.124.048385.