Abstract 2937: Cardiovascular Disease Risk Reduction Associated with Subsequent Systolic Blood Pressure Control Following Moderate and Severe Hypertension
Background: The relationship between hypertension (HTN) and subsequent cardiovascular (CV) events is well understood, however, there is little evidence available to guide clinicians to appropriate evidence-based target blood pressures for their hypertensive patients. This study examines the reduction in BP needed to subsequently overcome the risk associated with moderate and severe HTN.
Methods: Patient histories from 11 primary care practices beginning in 1997 were extracted from an electronic medical record. Patients were assigned a HTN class according to JNC 6 guidelines and subsequent CV events were identified. Cox proportional hazards regression was performed to estimate the risk of CV events according to baseline HTN class and the estimated hazard was then plotted against the mean follow-up SBP.
Results: A total of 1105 CV events occurred in 16,719 patients followed for a mean of 3.8 years, the mean age was 45 years, 61% female, 30% black, and 14% diabetic. Cox regression showed significant elevation of risk with each HTN class except pre-HTN. The slope for each hypertension group, representing the factor by which the hazard for a CV event increases for every 10 mmHg increase in mean follow-up SBP, was significantly greater than the preceding category (p < 0.0001 for all). The predicted regression lines for each baseline BP class are plotted below.
Conclusions: Current recommended BP targets are inadequate to sufficiently reduce the risk of CV events. To reduce the risk of CV events to levels approaching those with controlled mild HTN, patients developing moderate or severe HTN must reduce their mean follow-up SBP to 120 to 125 mmHg, well below the recommended target of < 140 mmHg.