Abstract 075: Does the Benefit From Treating to Blood Pressure Targets Vary With Age?

Hypertension guidelines differ regarding how blood pressure targets vary with age. Crucial to this debate is how the benefit of treatment might vary with age. Therefore, a systematic search was conducted for trials randomizing treatment in the more intensive arm to systolic blood pressure (SBP) targets generally recommended, i.e., 140 mmHg or less. Meta-analysis examined the effects of age on risk reduction. Sixteen trials met criteria with SBP targets of 120-140 mmHg. Relative to high targets, low targets reduced risk for cardiovascular events (CVEs), 0.86 (95% CI 0.75,0.98), P=0.019, but treatment benefit differed among trials. This heterogeneity was explained by patient age. Relative to high targets, low targets reduced risk in older patients (mean ages 74+): 0.77 (0.61,0.97), P=0.025, but not in younger patients (mean ages 55-67): 0.90 (0.78,1.03), P=0.121, even though the latter had much greater statistical power. Risk reduction from low targets was greater in older patients than in younger patients: Relative risk in older patients versus relative risk in patients 16 years younger (2 standard deviations of age) = 0.78 (95% CI 0.63,0.98), P=0.036 (see Figure). Although generally not statistically significant, similar patterns were seen for specific CVEs and total mortality. Risks for adverse effects also tended to decrease with age. The number needed to treat to low targets to prevent 1 CVE in 10 years for 2 typical populations declined with age from 45 to 14 and from 110 to 13. In conclusion, for both relative risk and absolute risk, treating to SBP targets of 120-140 mmHg was more beneficial in older patients than in younger patients with no age-related increase in adverse effects.