Impact of the comorbidities in the outcomes of a cohort of elderly patients affected by acute ischemic stroke

Background: Acute ischemic stroke (AIS) is common among elderly patients, affecting 6,5% of the population aged 64-85 years and representing the third cause of death among old subjects. Prevalence of chronic diseases is increasing worldwide: the association of two or more chronic conditions, called multimorbidity, is associated to a poor health status and reduced life expectancy, in particular among elderly patients. Moreover, multimorbidity has been associated to an increased rate of adverse events in several critical illnesses. We aimed to evaluate the number and the type of chronic pathologies in a cohort of elderly patients admitted in an Internal Medicine department for AIS. We also evaluated if the number of comorbidities reduced in-hospital survival in this specific population of patients. Methods: 294 consecutive patients admitted to our Internal Medicine Unit (IM) for AIS were enrolled. Age, sex, lenght of admission, in-hospital mortality and comorbidities (hypertension,diabetes, chronic cardiopathy, atrial fibrillation(AF), dyslipidemia, active cancer, COPD, chronic kidney disease (CKD) and dementia) were collected. The trend of days of hospitalization in relation with the number of comorbidities was evaluated with analysis of variance (ANOVA). Statistical analysis was performed with SPSS 13.0. Results: Mean age was 82,37 (±9,19) years. Mean length of stay in our department was 9,87 (±7,14) days. In-hospital mortality was 10,9%. Hypertension was present in 54%, diabetes in 18%, dyslipidemia in 11,9%, chronic cardiopathy in 36,4%, AF in 18,4%, cancer in 4,1%, COPD in 10,5%, CKD in 21,7% and cognitive deterioration in 13,3% of the sample. 93,4% of the subjects had at least one comorbidity, with a median of two concomitant pathologies at the admission in IM. We observed a linear trend in the days of admission proportional to the increasing number of comorbidities (from 7,35±3,97 days, no comorbidities to 16,00±12,52 days, >=4 comorbidities; p<0.05). Patients with 0 or 1 concomitant pathologies had a prevalence of in-hospital death rate of 2,3%, while subjects affected by 2 or more comorbid diseases ad a prevalence of 8,2%. Discussion: Proportion of world population people over 60 years will double by 2050. The proinflammatory status associated to degenerative aging processes represents the major underlying cause for chronic diseases. Aging itself is deemed to be the strongest risk factor for several chronic conditions, such as CVD, CKD, systemic atherosclerosis, dementia, diabetes, COPD and cancer. Thus, elderly patients are often affected by multimorbidity, which implies the coexistence of multiple chronic pathologies and increases the risk of multiple drug therapies, drug-drug and drug-pathology interactions. Aging increases the risk of AIS, with about one third of the events occurring in elderly patients. An increased stroke prevalence and a higher stroke-related mortality is observed among old or very old subjects.In this study we underline how most of the elderly subjects admitted by AIS is affected by one or more complicating pathologies and how the number of comorbidities is associated to and increased in-hospital length of stay and in-hospital death. Conclusions: Comorbidities are common in elderly patients admitted for AIS. An increased number of comorbidities is associated to longer in-hospital stay and a higher risk of in-hospital death. However, larger studies are required to validate these observations.