Comorbidity and the increased mortality after hospitalization for stroke: a population-based cohort study.

Essentials Comorbidity is prevalent in the stroke population and affects post-stroke survival. A stroke patient cohort (n = 201 691) and a general population cohort were followed for survival. Cancer and advanced renal/liver disease substantially increased one-year stroke mortality. Tailoring stroke interventions according to comorbidity may reduce excess mortality. SUMMARY: Background Comorbidity is prevalent among stroke patients, affecting post-stroke survival. It remains unknown whether comorbidity impacts post-stroke mortality beyond the combined individual effects of stroke and comorbidity. Methods Using nationwide Danish databases, we performed a cohort study of 201 691 patients ≥ 18 years old with incident ischemic stroke, intracerebral or subarachnoid hemorrhage, or unspecified stroke during 1995-2012, and 992 942 adults from the general population, matched to stroke patients by birth year, sex and individual comorbidities in the Charlson Comorbidity Index. During up to 5 years of follow-up, we computed standardized mortality rates (SMRs) to assess interaction contrasts as a measure of excess mortality not explained by the additive effects of stroke and comorbidity acting alone. Results Five-year post-stroke mortality was 48%, corresponding to an SMR of 187 deaths per 1000 person-years. During the 30-day peak post-stroke mortality (SMR, 180 per 1000 person-months), interaction with comorbidity represented 23%, 34% and 51% of post-stroke mortality rates among patients with low (score = 1), moderate (score = 2-3) and high (score = 4+) comorbidity based on Charlson Comorbidity Index scores. The interaction accounted for 5% to 32% of subsequent 31-365-day post-stroke mortality rates, depending on comorbidity level. The interaction contrasts were most notable among comorbid patients with cancer, particularly with hematological or metastatic disease, followed by patients with moderate-to-severe liver or renal disease. Conclusion Comorbidity, notably cancer and advanced renal or liver disease, increased 1-year mortality after stroke beyond the combined effects expected from either disease acting alone.

PO-06 - Cancer and the risk of venous thromboembolism in stroke patients.

INTRODUCTION: The impact of comorbidity and in particular cancer on the risk of venous thromboembolism (VTE) after stroke is poorly understood. AIM: We aimed to determine the impact of comorbidity, in particular cancer, on the risk of venous thromboembolism in stroke patients as the excess VTE rates not explained by stroke and comorbidity alone. MATERIALS AND METHODS: We used Danish national databases to conduct a cohort study including 110,833 patients diagnosed with an incident stroke (72% ischemic) between 1995 and 2012. A comparison cohort of 545,960 members of the general population was matched to the stroke patients by date of diagnosis, year of birth, sex, and specific comorbidities using the Charlson Comorbidity Index and other VTE risk factors. We computed VTE cumulative risks, rates and rate ratios, as well as the interaction with comorbidity (as the excess VTE rates not explained by stroke and comorbidity alone) during five years of follow-up. RESULTS: Five-year VTE risks were 2.16% and 1.85% in the stroke and general population comparison cohorts, respectively. Three-month VTE rate ratios peaked at a 6-fold increase (95% confidence interval: 4.9;6.2) in stroke patients and remained increased by 52%-20% relative to the general population at subsequent follow-up. 20% to 38% of the three-month VTE rates in the stroke cohort were attributable to the interaction between stroke and comorbidity in patients with moderate (2-3) to high (≥4) Charlson Comorbidity Index scores. Non-metastatic and metastatic solid tumors accounted for most of the observed interaction with stroke, representing 44% and 60% of their attributable three-month VTE rates. No interaction between comorbidity and stroke was observed during subsequent follow-up to 5 years. CONCLUSIONS: Cancer increased the risk of VTE within three months after the stroke.