For older patients with heart failure with preserved ejection fraction (HFpEF), systolic blood pressure (SBP) levels below 120 mm Hg—and even 130—are associated with worse short- and long-term cardiovascular outcomes, according to a study published online Feb. 14 in JAMA Cardiology.
Specifically, SBP below 120 was associated with double the risk of death within 30 days of discharge (10 percent versus 5 percent) and a 36 percent increased one-year mortality risk. Patients beneath that cutoff also saw a 47 percent increased risk of rehospitalization for heart failure at 30 days, but not at one or six years.
“These findings, taken together with those from multiple sensitivity cohorts, provide evidence of a consistent association between a lower SBP level and poor outcomes in patients with HFpEF,” wrote lead author Apostolos Tsimploulis, MD, and colleagues.
The researchers arrived at these conclusions by studying nearly 4,000 patients with ejection fraction of at least 50 percent and stable SBP levels varying by no more than 20 mm Hg from hospital admission to discharge. They then propensity-score matched 901 patients with SBP below 120 mm Hg to the same number of patients with higher SBP levels but otherwise similar baseline characteristics. The final analysis cohort was 79 years old on average, 63.7 percent women and 7.4 percent African-American.
Interestingly, Tsimploulis et al. discovered discharge SBP below 130 mm Hg was also significantly associated with adverse outcomes, though not to the extent of levels under 120 mm Hg.
“Findings from the current study provide evidence that a lower SBP level is a marker of underlying pathophysiologic processes that is associated with poor outcomes in patients with HFpEF, an observation that may help design future trials testing new therapies in HFpEF,” the authors wrote. “Future prospective randomized clinical trials also need to examine the effect of various SBP target levels on outcomes in patients with HFpEF.”
Tsimploulis and colleagues noted there was no data on SBP levels after discharge, so patients may have crossed over from one group to the other during follow-up. If anything, though, this would likely cause an underestimation of the association between low blood pressure and cardiovascular events in this population, the authors pointed out.
Another potential limitation of the study is data were collected in 2003 and 2004 and follow-up ended in 2008; treatment of HFpEF patients may have changed since that period.