Differential impact of syncope on the prognosis of patients with acute pulmonary embolism: a systematic review and meta-analysis

Eur Heart J. 2018 Dec 14;39(47):4186-4195. doi: 10.1093/eurheartj/ehy631.

Abstract

Aims: Controversial reports exist in the literature regarding the prognostic role and therapeutic implications of syncope in patients with acute pulmonary embolism (PE). We conducted a systematic review and meta-analysis to investigate the association between syncope and short-term adverse outcomes, taking into account the presence or absence of haemodynamic compromise at acute PE presentation.

Methods and results: The literature search identified 1664 studies, 29 of which were included for a total of 21 956 patients with PE (n = 3706 with syncope). Syncope was associated with higher prevalence of haemodynamic instability [odds ratio (OR) 3.50; 95% confidence interval (CI) 2.67-4.58], as well as with echocardiographic signs of right ventricular (RV) dysfunction (OR 2.10; CI 1.60-2.77) at presentation. Patients with syncope had a higher risks of all-cause early (either in-hospital or within 30 days) death (OR 1.73; CI 1.22-2.47) and PE-related 30-day adverse outcomes (OR 2.00; CI 1.11-3.60). The absolute risk difference (95% CI) for all-cause death was +6% (+1% to +10%) in studies including unselected patients, but it was -1% (-2% to +1%) in studies restricted to normotensive patients. We observed no prognostic impact of syncope in studies with a lower score at formal quality assessment and in those conducted retrospectively.

Conclusion: Syncope as a manifestation of acute PE was associated with a higher prevalence of haemodynamic instability and RV dysfunction at presentation, and an elevated risk for early PE-related adverse outcomes. The association with an increased risk of early death appeared more prominent in studies including unselected patients, when compared with those focusing on normotensive patients only.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't
  • Systematic Review

MeSH terms

  • Acute Disease
  • Blood Pressure / physiology*
  • Echocardiography
  • Global Health
  • Humans
  • Incidence
  • Prognosis
  • Pulmonary Embolism / complications*
  • Pulmonary Embolism / diagnosis
  • Pulmonary Embolism / physiopathology
  • Survival Rate / trends
  • Syncope / epidemiology
  • Syncope / etiology*
  • Syncope / physiopathology