In hospitalized older people with heart failure with preserved ejection fraction (HFpEF), a systolic blood pressure level less than 120 mm Hg is independently associated with mortality and readmissions, according to a large observational study.
Systolic pressure under 120 mm Hg at discharge was associated with 2.07-fold risk (95% CI 1.45-2.95, P<0.001) of all-cause mortality within 30 days compared with higher blood pressure in matched patients, Ali Ahmed, MD, MPH, of the Veterans Affairs Medical Center in Washington, D.C., and colleagues reported online in JAMA Cardiology.
Systolic blood pressure (SBP) less than 120 mm Hg was also associated with a higher risk of mortality at 1 year (HR 1.36, 95% CI 1.16-1.59, P<0.001) and across the average follow-up of 2.1 years (HR 1.17, 95% CI 1.05-1.30, P=0.005).
A higher risk of heart failure readmission was also noted at 30 days (HR 1.47, 95% CI 1.08-2.01, P=0.02) but not at 1 year or the overall up to 6 years of follow-up. Hazard ratios for the combined endpoint of heart failure readmission or all-cause mortality associated with a low systolic level less than 120 mm Hg were:
- At 30 days, 1.71 (95% CI 1.34-2.18 P<0.001)
- At 1 year, 1.21 (95% CI 1.07-1.38 P=0.004)
- Overall, 1.12 (95% CI 1.01-1.24 P=0.03)
Notably, “this association was essentially unchanged when lower SBP was defined as SBP levels less than 130 mm Hg. An SBP level less than 120 mm Hg was also associated with a significantly higher risk of the combined endpoints of heart failure readmission or mortality at all 3 times,” they wrote.
The study found no evidence of a nonlinear association between SBP and all cause mortality (P>0.20), they noted. “The association between SBP levels less than 120 mm Hg and overall all-cause mortality in our matched cohort was homogenous across various clinically relevant subgroups of patients, except those with a glomerular filtration rate less than 45 mL/min/1.73m2 and those who received a discharge prescription for ACE inhibitors.”
National guidelines for HF recommend that SBP levels should be controlled in patients with heart failure with preserved ejection fraction (HFpEF) in general, and the new 2017 blood pressure guidelines suggest an optimal target level of less than 130 mm Hg in patients with HFpEF and persistent hypertension. However, “an optimal SBP target level is less clear for patients with HFpEF,” the group noted.
“These recommendations are extrapolated from populations without heart failure because direct evidence from patients with HFpEF is limited,” they opined. “The ACE inhibitors and angiotensin II receptor blockers have been shown to modestly lower SBP levels in patients with HFpEF, but this did not translate into better outcomes.”
Ahmed’s group suggested that this and other observational studies linking lower SBP level with poor outcomes in HF patients may reflect the poorly understood phenomenon of reverse epidemiology. “Future prospective randomized clinical trials need to examine the effect of various SBP target levels on outcomes in patients with HFpEF.”
The study assessed data from the Medicare-linked Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure (OPTIMIZE-HF) registry, which included more than 25,000 patients hospitalized nationwide between March 1, 2003, and Dec. 31, 2004.
Among them, 35% had an ejection fraction of at least 50%. Analysis was restricted to include the 44% of those low ejection fraction patients with stable inpatient SBP levels that varied 20 mm Hg or less from admission to discharge.
Of this cohort of almost 4,000 patients, 27% had SBP levels less than 120 mm Hg. The main analyses were on a group of 1,802 patients with higher or lower SBP who were propensity score matched on 58 baseline characteristics.
Limitations include the study’s observational nature, its potential for bias due to unmeasured confounders, and unknown generalizability to ambulatory patients with HFpEF because of differences in blood pressure determinants and measurement by setting.
While the study raised some interesting hypotheses, Willie Lawrence, MD, of the Research Medical Center in Kansas City, Missouri, echoed authors’ observations regarding the study’s lack of generalizability. He cautioned that randomized double blind studies are needed, noting that studies like SPRINT and ACCORD provide a strong basis for guideline recommendations.
As well, he noted many confounders: The diagnosis of heart failure with preserved ejection fraction is “a hodge podge of diagnoses that might include renal failure, chronic lung disease, or diastolic dysfunction for instance; heart failure is treated differently now than it was at the time of this study.”
The Organized Program to Initiate Lifesaving Treatment in Hospitalized Patients with Heart Failure (OPTIMIZE-HF) was sponsored by GlaxoSmithKline.
Ahmed was supported by the National Institutes of Health grants from the National Heart, Lung, and Blood Institute.
Several authors disclosed relevant relationships with industry.
F. Perry Wilson, MD, MSCE Assistant Professor, Section of Nephrology, Yale School of Medicine and Dorothy Caputo, MA, BSN, RN, Nurse Planner