Low systolic blood pressure signals a high risk of death in people with acute heart failure

A simple systolic blood pressure reading on admission can provide important prognostic information for people presenting to hospital with acute heart failure, say researchers from the US who found a clear link between higher systolic blood pressure and lower mortality among more than 48 000 adults. In-hospital mortality was 7.2% for patients with the lowest blood pressures (<120 mm Hg), falling to 1.7% among those with the highest (>161 mm Hg). The trend was significant, with no apparent ceiling to the effect. Even those with blood pressures over 189 mm Hg on admission had an in-hospital mortality below 2%. Death rates up to 90 days followed a similar pattern.

Low systolic blood pressure was a poor indicator of prognosis, regardless of the patient's ejection fraction. Overall, the odds of dying in hospital increased by 21% (95% CI 17% to 25%) for every 10 mm decrease in systolic blood pressure below 160 mm Hg.

It's likely that systolic blood pressure on admission divides patients with acute heart failure into two distinct groups, write the researchers. Women, African Americans, and people with a well preserved ejection fraction seem over-represented at the top end of the blood pressure range, while men, and people with ischaemic heart disease and poor ejection fraction, are over-represented at the bottom. Clinical trials of treatments should probably consider these groups separately.