Hyponatremia and Short-term Prognosis of Patients with Acute Pulmonary Embolism: A Meta-analysis

Objectives: The aim of this study was to assess the relationship between hyponatremia and the short-term prognosis of patients with acute pulmonary embolism (PE).

Methods: Searches of MEDLINE (1966-) and ISI Databases (1965-) were performed for English language studies. Odds ratio (OR) and adjusted hazard ratio (HR) for short-term prognosis were calculated for PE patients with or without hyponatremia. Meta-analysis was carried out following Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines.

Results: Eight studies with 18,616 patients were included in this meta-analysis. The mean in-hospital mortality was 12.9% in hyponatremia group, compared with 2.3% in normonatremia group. Meta-analysis showed the summary OR was 5.586 (95% CI 3.424 to 9.112). The mean 30-day mortality was 15.9% in hyponatremia group, compared with 7.4% in normonatremia group. The summary OR was 3.091 (95% CI 1.650 to 5.788). No significant publication bias was found for the meta-analysis. Sensitivity analyses by only pooled the adjusted HRs showed the summary HR was 0.924 (95% CI 0.897 to 0.951), which indicted the mortality risk will be decrease to 0.924 times for per-1mmol/L sodium increase in hyponatremia patients.

Conclusions: Our meta-analysis indicates that hyponatremia was related with poor short-term prognosis in patients with acute PE. Hyponatremia is a simple, cheap, powerful marker of mortality, which should be used routinely tested in the PE prognostic assessment.