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Hypertension Severity as Quantified by Hypertension Daily Dose and Blood Pressure With Risk of Stroke in REGARDS
Ying K Loo1, Katherine Wilkinson1, Tyler Harkness1
1The Robert Larner, M.D. College of Medicine at the University of Vermont Burlington VT USA.
Insights
High blood pressure (BP) and higher doses of antihypertensive medications increase stroke risk. However, for individuals with BP below 140 mmHg, stroke risk remained similar regardless of medication intensity.
Area of Science:
- Cardiovascular Medicine
- Neurology
- Public Health
Background:
- The relationship between blood pressure (BP) and stroke risk, particularly concerning antihypertensive medication intensity, remains unclear.
- Understanding this relationship is crucial for optimizing stroke prevention strategies.
Purpose of the Study:
- To investigate the association between BP levels, antihypertensive medication intensity, and the risk of incident stroke.
- To determine if higher medication intensity modifies stroke risk at different BP levels.
Main Methods:
- The Reasons for Geographic and Racial Differences in Stroke (REGARDS) study enrolled over 30,000 participants.
- Cox proportional hazard models were used to analyze the hazard ratio (HR) of incident stroke based on systolic BP and hypertension daily dose (HDD) tertiles.
- Follow-up included biannual phone calls and medical record review to ascertain stroke events.
Main Results:
- Systolic BP ≥140 mmHg combined with HDD tertile ≥2 was associated with significantly increased stroke risk.
- Specifically, HRs ranged from 2.33 to 3.66 for these combined conditions compared to BP <120 mmHg with no medication.
- For individuals with systolic BP <140 mmHg, stroke risk was comparable across all HDD levels.
Conclusions:
- Elevated systolic BP (≥140 mmHg) coupled with substantial antihypertensive medication use (HDD tertile ≥2) elevates stroke risk.
- Lowering BP with antihypertensive medications is supported as a strategy to mitigate stroke risk, especially in those with higher BP.
- Stroke risk appears consistent across varying medication intensities for individuals maintaining BP below 140 mmHg.
Background:
It is unknown how blood pressure (BP) relates to stroke risk across levels of hypertension daily dose (HDD)-quantified antihypertensive medication intensity.
Methods And Results:
The REGARDS (Reasons for Geographic and Racial Differences in Stroke) study enrolled 30 239 participants from the 48 contiguous US states in 2003 to 2007 with in-person follow-up in 2013 to 2016 (Visit 2). We included those without prior stroke at Visit 2, treating this visit as T0. Biannual phone calls and medical record review ascertained incident stroke events. Cox proportional hazard models estimated the hazard ratio (HR) of incident stroke by treatment intensity defined by systolic BP stages and HDD groupings. There were 344 stroke events over a median 5.5 years. Relative to systolic BP <120 mm Hg and no antihypertensive medications, the stroke HR was 2.86 (95% CI, 1.68-4.85) for systolic BP 140 to 159 mm Hg and HDD tertile 2, 2.33 (1.37-3.97) for systolic BP 140 to 159 mm Hg and HDD tertile 3, 3.08 (1.20-7.88) for systolic BP ≥160 mm Hg and HDD tertile 2, and 3.66 (1.61-8.30) for systolic BP ≥160 mm Hg and HDD tertile 3. Stroke risk was similar across HDD levels for people with systolic BP <140 mm Hg.
Conclusions:
Among adults without prior stroke, systolic BP ≥140 mm Hg and HDD tertile ≥2 was associated with greater stroke risk. For adults with BP <140 mm Hg, stroke risk was similar despite cumulative dose of antihypertensive medications used. These findings support the practice of BP-lowering medications to mitigate stroke risk.
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