Prognostic value of blood pressure in ambulatory heart failure: a meta-analysis and systematic review. Ambulatory blood pressure predicts heart failure prognosis

Previous primary studies have explored the association between blood pressure (BP) and mortality in ambulatory heart failure (HF) patients reporting varying and contrasting associations. The aim is to determine the pooled BP prognostic value and explore potential reasons for between-study inconsistency. We searched Medline, Cochrane, EMBASE and CINAHL from January 2005 to October 2018 for studies with ≥ 50 events (mortality and/or hospitalization) and included BP in a multivariable model in ambulatory HF patients. We pooled hazard ratios (random effects model) for systolic BP (SBP) or diastolic BP (DBP) effect on mortality and/or hospitalization risk. We used a priori defined sub-group analyses to explore heterogeneity and GRADE approach to assess the certainty of the evidence. Seventy-one eligible articles (239,467 screened) at low to moderate risk of bias included 235,752 participants. Higher SBP was associated with reduced all-cause mortality (HR 0.93, 95%CI 0.91–0.95, I2 = 87.13%, moderate certainty), all-cause hospitalization events (HR 0.91, 95%CI 0.88–0.93, I2 = 44.4%, high certainty) and their composite endpoint (HR 0.93 per 10 mmHg, 95%CI 0.91–0.94, I2 = 86.3%, high certainty). DBP did not demonstrate a statistically significant effect for all outcomes. The association strength was significantly weaker in studies following patients with either LVEF > 40%, higher average SBP (> 130 mmHg), increasing age and diabetes. All other a priori subgroup hypotheses did not explain between study differences. Higher ambulatory SBP is associated with reduced risk of all-cause mortality and hospitalization. Patients with lower BP and reduced LVEF are in a high-risk group of developing adverse events with moderate certainty of evidence.