Impact of lower achieved blood pressure on outcomes in hypertensive patients

Hypertensive patients with ECG left-ventricular hypertrophy (LVH) are at increased risk of cardiovascular morbidity and mortality, and regression of ECG LVH is associated with improved cardiovascular outcomes. Although tighter control of systolic blood pressure (SBP) has been associated with a lower rate of ECG LVH, whether tighter vs. standard control of SBP is associated with greater reduction of cardiovascular risk is unclear.

Risk of stroke, myocardial infarction (MI), cardiovascular death, the composite endpoint of these events and all-cause mortality were examined in relation to in-treatment achieved SBP in 9193 hypertensive patients with ECG LVH randomly assigned to losartan or atenolol-based treatment. Patients with in-treatment SBP 130 mmHg or less (lowest quintile at last measurement) and SBP between 131 and 141 mmHg were compared with patients with in-treatment SBP at least 142 mmHg (median SBP at last measurement). In univariate analyses, compared with in-treatment SBP at least 142 mmHg, in-treatment SBP between 131 and 141 mmHg entered as a time-varying covariate identified patients with significantly lower risk of all events. In contrast, patients with SBP 130 mmHg or less had less reduction in MI, stroke and composite endpoint and no significant decrease in cardiovascular or all-cause mortality. In multivariate Cox analyses adjusting for baseline risk factors and randomized treatment as standard covariates and in-treatment diastolic BP, heart rate and Cornell product LVH as time-varying covariates, an in-treatment achieved SBP of 131 to 141 mmHg remained associated with a significantly decreased risk of MI, stroke and the LIFE composite endpoint. In contrast, patients who achieved a SBP 130 mmHg or less had no significant reduction in risk of MI, stroke or composite endpoint, had a trend to increased cardiovascular mortality [hazard ratio 1.32, 95% confidence interval (CI) 0.97-1.81, P = 0.078] and a statistically significant 37% increased risk of death from any cause (hazard ratio 1.37, 95% CI 1.10-1.71, P = 0.005).

Achieved SBP 130 mmHg or less is not associated with lower cardiovascular risk than SBP of 131 to 141 mmHg and is associated with a significantly increased risk of death and trend towards increased cardiovascular mortality. These findings support the need for randomized evaluation of treatment to more aggressive vs. conventional SBP targets.