January 1, 1989Clinical and Experimental Hypertension
The Effects of Antihypertensive Drug Treatment on the Incidence of Stroke and of Coronary Heart Disease
Key result
Antihypertensive drugs cut stroke risk ~40% and modestly reduce CHD.
- 10% reduction in CHD risk
- 95% CI 0-20
- n=460,000
Why the study?
Does antihypertensive drug treatment reduce the incidence of stroke and coronary heart disease in hypertensive patients?
Key Points
- To compare the effects of diastolic blood pressure reduction on stroke and coronary heart disease risk between long-term observational studies and shorter-term randomized trials of antihypertensive drugs.
- Examined prospective observational data across nine cohorts involving approximately 420,000 men and women followed for 6 to 25 years.
- Synthesized overviews of randomized controlled trials involving 30,000 to 40,000 hypertensive patients evaluating antihypertensive drug therapy over several years.
- In prospective observational studies, a sustained 6 mmHg lower diastolic blood pressure was associated with 36% (± 2%) fewer strokes and 22% (± 1%) fewer coronary heart disease deaths and non-fatal myocardial infarctions.
- In randomized trials, antihypertensive treatment reduced stroke risk by approximately 40%, demonstrating that the full long-term stroke benefit of lower blood pressure is achieved within 3 years.
- Active drug treatment reduced coronary heart disease risk by approximately 10% (95% CI, 0% to 20%), an effect notably smaller than the 22% risk reduction predicted by observational cohorts.
Structured PICO
Does antihypertensive drug treatment reduce the incidence of stroke and coronary heart disease in hypertensive patients?
P
Population
Review of 9 prospective observational studies (about 420,000 individuals followed for 6-25 years) and several overviews of RCTs (30,000-40,000 hypertensive patients) evaluating the effects of diastolic blood pressure reduction.
I
Intervention
Antihypertensive drug treatment lowering diastolic blood pressure (DBP) by approximately 6 mmHg
C
Comparator
Higher usual DBP (observational studies) or control allocation (RCTs)
O
Outcome
Incidence of stroke and coronary heart disease (CHD deaths and non-fatal myocardial infarctions)hard clinical
Main Result
Effect estimate: 10% reduction in CHD risk (95% CI 0-20)
Antihypertensive treatment rapidly achieves the full expected epidemiological benefit for stroke reduction, but falls short for CHD reduction, possibly due to chronic disease processes or drug side effects.
Limitations
- Apparent shortfall in CHD reduction may reflect chronic pathophysiological processes in the relationship between DBP and CHD, and/or possible cardiotoxic side-effects of the principal trial treatments.
- Shortfall in CHD reduction may reflect chronic pathophysiological processes
- Possible cardiotoxic side-effects of principal trial treatments
Authors
Discussion
No takes yet. Share an insight, caveat, or question.
Implication
Supports BP control for stroke prevention in hypertension; leaves open mechanisms behind lesser CHD benefit.
Cite This Study
Stephen MacMahon (1989) conducted a review in Hypertension (n=460,000). Antihypertensive drug treatment vs. Control/Higher diastolic blood pressure was evaluated on Incidence of stroke and coronary heart disease (10% reduction in CHD risk, 95% CI 0-20). Antihypertensive drug treatment reduced the risk of stroke by about 40% and coronary heart disease by about 10% (95% CI 0-20% reduction).