Abstract 18417: Complex Interaction of the Prognostic Value of Systolic Blood Pressure with the Degree and Type of Heart Failure
Introduction: Low systolic blood pressure (SBP) is associated with higher mortality in heart failure (HF) patients whereas hypertension is associated with worse outcomes in patients without HF. However, this possible non-linear relationship between SBP and mortality in patients with ambulatory HF has not been well studied.
Hypothesis: We hypothesized that SBP does not have a linear relationship with mortality and interacts with the severity and type of HF.
Methods: We evaluated a national cohort of 9442 ambulatory HF patients (70±10 years; 95% men) with a total of 16489 person-years of follow-up, for association of SBP with all-cause mortality. To evaluate the optimal range of SBP, we used spline fitted Cox regression with all-cause mortality as the end-point and 22 other baseline characteristics as covariates.
Results: In 9442 patients, SBP was associated with mortality (HR=0.994, χ2=33, p<0.001) in the adjusted model. After spline fit, the protective effect of SBP in all HF patients plateaued at 120 mmHg (χ2=57, p<0.001, Figure). In 3693 mild/moderate HFREF patients (30%≤EF<50%), SBP was associated with mortality (HR=0.996, x2=4, p=0.04) that improved significantly on spline fit resulting in U shaped association with mortality (χ2=17, p<0.001, Figure). In 2906 severe HFREF patients (EF<30%), SBP was associated with mortality (HR=0.990, χ2=28, p<0.001) that did not change much on spline fit (χ2=37, p<0.001, Figure). In 2843 patients with HFPEF (EF≥50%) , SBP was associated with mortality (HR=0.995, χ2=6, p=0.01) which changed significantly with spline fit with lowest mortality between 130 and 160 mmHg, a significant increase below and a trend towards increase above these values (χ2=10, p=0.002, Figure).
Conclusion: Relationship of SBP with outcomes is complex and interacts with the severity and type of HF. A better understanding of this relationship will help both in better prognostication as well as in setting optimal targets for SBP.
- © 2010 by American Heart Association, Inc.