Objectives: A goal SBP 120 mmHg or less reduced mortality in high-risk Systolic Blood Pressure Intervention Trial patients; however, mortality implications of concomitant DBP lowering in coronary artery disease (CAD) are uncertain. We examined the relationship between DBP lowering and all-cause mortality with lower achieved SBPs in a large cohort.
Methods: We categorized 17 131 hypertensive patients from the INternational VErapamil-trandolapril STudy US cohort, aged at least 50 years with CAD, by mean achieved SBP (<120, 120 to <130, 130 to <140, and ≥140 mmHg) and DBP tertiles (low, middle, and high per SBP category) during active follow-up. Long-term mortality was determined via National Death Index. Multivariable Cox regression was performed to investigate the impact of DBP lowering among all SBP categories and within each SBP category.
Results: There were 6031 deaths over mean follow-up of 11.6 years (198 352 patient-years). In unadjusted analyses, achieving DBP in the lowest tertile portended greatest mortality risk across all SBP categories. In multivariate analysis, using SBP 120 to less than 130 mmHg, DBP at least 79 mmHg as reference (mortality nadir), achieving DBP in the lowest tertile (DBP < 69 mmHg) was associated with excess mortality risk among those with SBP less than 120 mmHg (adjusted hazard ratio 1.60; 95% confidence interval, 1.33-1.91). However, among those with SBP 120 to less than 140 mmHg, adjusted mortality risk did not differ significantly with low DBPs. Among those with SBP at least 140 mmHg, mortality risk remained high regardless of DBP.
Conclusion: In older CAD patients, the mortality risk related to excess DBP lowering is accentuated in those achieving intensive SBP control less than 120 mmHg, raising concerns about intensive SBP lowering in these patients.