PREDICTORS OF IN-HOSPITAL MORTALITY AMONG ACUTE ISCHAEMIC STROKE PATIENTS IN A TERTIARY HEALTH INSTITUTION IN NIGERIA.

Introduction: Stroke is a disease of immense public health importance with grave economic and social implications and the public health burden of stroke is set to rise over future decades particularly in developing countries. Acute ischaemic stroke is a significant cause of morbidity and mortality globally, constituting a major challenge to healthcare systems in developing countries. Ischaemic stroke accounts for about 62.4% - 80% of strokes. The mortality rate (16.2 - 30%) among patients with acute ischaemic stroke (AIS) is high despite advances in stroke care in many tertiary health institutions in Africa. The prevalence of stroke in Rivers State is 13.31/1000 which is higher than the 7.7/1000 reported in Nigeria with significant mortality. Understanding and identifying the key predictors of in-hospital mortality of AIS can provide insights into the intricacies of stroke care in a tertiary health institution and guide the strategies to reduce these adverse outcomes. This study aimed to determine the predictors of mortality among acute ischaemic stroke patients at the University of Port-Harcourt Teaching Hospital, Rivers State.

Methods: This was a prospective study conducted at the University of Port-Harcourt Teaching Hospital (UPTH) over 10 months (January 2023 - October 2023). Consecutive consenting adult patients with both clinical and radiological confirmation of acute ischaemic stroke within one week of symptom onset were recruited into the study. The National Institutes of Health Stroke Scale (NIHSS) was used to assess stroke severity on presentation, while the short-term mortality rate was calculated. Patients were managed conservatively in line with recommended guidelines. Relevant clinical data were collected and analyzed using the using the Statistical Package for Social Sciences (SPSS) version 26. Odd ratio was calculated in a multivariate model to determine the predictors of in-hospital mortality among acute ischaemic stroke patients. A p-value of <0.05 was considered statistically significant.

Result: Out of the 110 participants studied, 51.8% were males and 48.2% were females with a female-to-male ratio of 1:1.1 and mean age of 60.1 (SD± 11.1) years. Hypertension was present in 90.9%, followed by dyslipidaemia (41.8%) and diabetes mellitus (39.1%). Hemiparesis (94.5%) and dysphasia (79.1%) were the most common neurological deficits observed. Approximately 56% of the participants had moderate stroke severity (NIHSS: 5 - 15) at presentation. Small vessel occlusion was the commonest ischaemic subtype accounting for about 41.7%. The most common neurological complications were delirium 71 (64.5%) and dysphagia 58 (52.7%) while the most frequent medical complications were bladder incontinence 59 (53.6%) and chest infection 57 (51.8%). The 30-day mortality rate was 20% (22) with most of the deaths occurring after the first seven days of hospitalization. Significant predictors of poor stroke outcome were coma at presentation, presence of neurological complications (such as delirium and dysphagia), and large infarct size of >50ml.

Discussion: This study observed that the sex distribution of males and females was similar. This suggests that the prevalence of stroke may be rising in females possibly due to increasing prevalence of gender-related factors such as oral contraceptive use and use of hormonal therapies pregnancy-related disorders (preeclampsia, gestational hypertension), and a higher prevalence of migraine. The study revealed that the predictors of poor stroke outcome were coma at presentation, presence of neurological complications (such as delirium and dysphagia), and large infarct size of >50ml. Dysphagia is a major risk factor for aspiration pneumonitis which is associated with high mortality among admitted AIS patients. The mortality rate in our study was comparable to the findings from a similar study by Sarbazi et al (21.7%). Higher values have been observed in similar studies in Nigeria (Ogun et al). However, the increased mortality recorded in this study was due to late hospital presentation, lack of intensive monitoring devices, and the presence of neurological complications.

Conclusion: Ischaemic stroke remains a significant medical cause of mortality among hospitalized patients. Enlightenment with a focus on aggressive stroke risk factor control and timely identification and management of poor outcome predictors in stroke patients will go a long way in improving stroke outcome parameters. Lastly, there is a need to step up efforts towards providing acute stroke care infrastructures such as stroke units in our tertiary health institution. This effort might hopefully help reduce stroke mortality among hospitalized AIS patients in resource-constrained settings.