Factors of importance for risk and prognosis of intracerebral haemorrhage

Abstract

Background and aims: Worldwide, the burden of haemorrhagic stroke increased significantly between 1990 and 2010, in terms of the absolute number of people with incident events, number of deaths, and disability-adjusted life years lost. This thesis aims to elucidate risk factors for occurrence and poor prognosis of intracerebral haemorrhage (ICH) in the hope that this will allow interventions to be developed that will reduce ICH occurrence and improve acute management of ICH. Methods: Secondary analyses of the datasets from international randomised trials - the pilot and main phases of the Intensive Blood Pressure Reduction in Acute Cerebral Haemorrhage Trials (INTERACT1 and INTERACT2) were conducted to determine the role of environmental and metabolic factors on the risk and outcome of ICH. Results: A dose-dependent relationship was observed between cold temperature and ICH risk within three hours after exposure. However, ambient temperature did not appear to have any appreciable effect on ICH severity according to baseline haematoma volume, and NIHSS and GCS scores. Interestingly though, there was an association of increased ambient temperature and perihaematomal oedema volume. My study on circadian variation in ICH characteristics and severity showed that patients whose ICH onset occurred in the early morning (00:00-07:59) and evening (16:00-15:59) had a higher risk of decreased consciousness (GCS≤8). Patients with moderate–severe decrease in eGFR had poor outcome at 90 days: their risk of death or major disability was near double those with normal renal function (odds ratio 1.82; 95% confidence interval, 1.28–2.61). Furthermore, hyponatraemia was an independent prognostic factor for 90-day mortality which may be attributed to large haematomas and/or IVH extension in the deep cerebral hemisphere. Conclusions: The data outlined in this thesis establish an association between acute exposure to cold ambient temperature and ICH occurrence, and reduced renal function and hyponatraemia are prognostic variables in ICH. Interventions and management v strategies to address these risk factors could be potentially beneficial in preventing ICH occurrence and optimising patient outcomes after ICH.