Cardiac dysfunction in patients affected by subarachnoid haemorrhage affects in-hospital mortality

Background: Subarachnoid haemorrhage (SAH) is a life-threatening condition with associated brain damage. Moreover, SAH is associated with a massive release of catecholamines, which may promote cardiac injury and dysfunction, possibly leading to haemodynamic instability, which in turn may influence a patient's outcome. Objectives: To study the prevalence of cardiac dysfunction (as assessed by echocardiography) in patients with SAH and its effect on clinical outcomes. Design: Systematic review of observational studies. Data sources: We performed a systematic search over the last 20 years on MEDLINE and EMBASE databases. Eligibility criteria: Studies reporting echocardiography findings in adult patients with SAH admitted to intensive care. Primary outcomes were in-hospital mortality and poor neurological outcome according to the presence or absence of cardiac dysfunction. Results: We included a total of 23 studies (4 retrospective) enrolling 3511 patients. The cumulative frequency of cardiac dysfunction was 21% (725 patients), reported as regional wall motion abnormality in the vast majority of studies (63%). Due to the heterogeneity of clinical outcome data reporting, a quantitative analysis was carried out only for in-hospital mortality. Cardiac dysfunction was associated with a higher in-hospital mortality [odds ratio 2.69 (1.64 to 4.41); P  < 0.001; I2 = 63%]. The GRADE of evidence assessment resulted in very low certainty of evidence. Conclusion: About one in five patients with SAH develops cardiac dysfunction, which seems to be associated with higher in-hospital mortality. The consistency of cardiac and neurological data reporting is lacking, reducing the comparability of the studies in this field.