Multimorbidity and predictors of mortality among patients with cardiovascular disorders admitted to an intensive care unit: a retrospective study

Background: Prevalence of cardiovascular risk factors is reported to be increasing in Ethiopia. Multimorbidity of these risk factors is more likely to lead cardiovascular disease (CVD) with increased hospital admission, premature death, and poor quality of life and increase health care expenditure. There is little evidence regarding magnitude and outcome of CVD multimorbidity, particularly in the African setting. The aim of this study was to examine the magnitude of multimorbidity and predictors of mortality in patients with cardiovascular disease admitted to the Medical Intensive Care Unit of St. Paul's Hospital Millennium Medical College, Addis Ababa, Ethiopia. Methods: A five-year retrospective study was conducted from 01 November 2015 to 01 January 2016. A total of 362 patients with cardiovascular disease who were admitted to the Medical Intensive Care Unit participated in the study. The primary endpoint was death from any cause in the Medical Intensive Care Unit while the secondary was a cardiovascular composite. For baseline characteristics and survival analysis we classified patients according to their level of multimorbidity. We used Cox proportional hazards models to evaluate the prognostic effect of the level of risk factors or multimorbidity at admission while controlling for confounding variables. Results: A total of 71 (19.6%) patients had a diagnosis of multimorbidity. The most common cases of cardiovascular admission were heart failure, 137 (37.8%), acute myocardial infarction, 83 (22.9%), hemorrhagic stroke, 95 (26.2%) and ischemic stroke, 24 (6.6%). There were 162 (45%) deaths. Myocardial infarction (COR 0.3; 0.18-0.53), hemorrhagic stroke (COR 3.3; 2.0-5.5) and age groups 55-64 years (COR 2.7; 1.2-6.1) and 65-74 years (COR 2.6; 1.1-6.1) were significantly associated with mortality. Conclusions: There is a significant proportion of multimorbidity in our study population. Multimorbidity may be used as a criterion to prioritize and improve the management of patients. Measures to prevent cardiovascular disease in people who already have hypertension, diabetes or underlying causes of heart failure in primary care settings need to be emphasized. At higher levels of care, capacity building is key to addressing the management of patients who present with acute cardiovascular diseases.