Low blood pressure predicts increased mortality in very old age even without heart failure: the Leiden 85-plus Study

To investigate whether low systolic blood pressure is predictive for increased mortality risk in 90-year-old subjects without heart failure, defined by low levels of NT-proBNP, as well as in 90-year-old subjects with high levels of NT-proBNP.

This study was embedded in the Leiden 85-plus Study, an observational population-based prospective study. All 90-year-old participants (n = 267) were included between 2002 and 2004 and followed up for mortality for at least 5 years. Differences in mortality risks were compared between participants with low systolic blood pressure (≤150 mmHg) and high systolic blood pressure (>150 mmHg) within strata of low NT-proBNP (<284 pg/mL for women and <306 pg/mL for men = lowest tertile) vs. high NT-proBNP (middle and highest tertile) at age 90 years. During maximal follow-up of 7.2 years, 212 participants (79%) died. Among participants with low NT-proBNP, low systolic blood pressure gave a two-fold increased risk (hazard ratio 2.0, 95% confidence interval 1.1-3.4) compared with participants with high systolic blood pressure. For participants with high NT-proBNP, low systolic blood pressure provided a 1.7 increased mortality risk (95% confidence interval 1.2-2.3) compared with high systolic blood pressure.

Low systolic blood pressure is predictive for increased mortality risk in 90-year-old subjects, irrespective of the NT-proBNP level. Therefore, the absence or presence of heart failure as determined by NT-proBNP does not influence the prognostic value of low systolic blood pressure with regard to mortality in the oldest old.