Strict blood glucose control with insulin during intensive care after cardiac surgery: impact on 4-years survival, dependency on medical care, and quality-of-life

Abstract

To document the impact of intensive insulin therapy during intensive care on long-term (4 years) outcome of high-risk cardiac surgery patients. In this pre-planned sub-analysis and follow-up study of a large, randomized controlled trial on the effects of intensive insulin therapy during critical illness, we assessed long-term outcome in the 970 patients who had been admitted after high-risk cardiac surgery (mean+/-SD EuroSCORE of 6.0+/-3.7; EuroSCORE-predicted hospital mortality of 9.9%; observed hospital mortality of 7.5% in the conventional insulin group and 3.4% in the intensive insulin group). Long-term outcome was quantified as: (a) 4 years survival; (b) incidence of hospital re-admission; (c) level of activity and medical care requirements at 4 years as assessed by the Karnofsky score; and (d) perceived health-related quality-of-life at 4 years as assessed by the Nottingham Health Profile. Four years after ICU admission, the number of post-hospital discharge deaths was similar in the two study groups, reflecting maintenance of the acute survival benefit with intensive insulin therapy. Survivors who had been treated with intensive insulin during ICU stay revealed a similar risk for hospital re-admission and a comparable level of dependency on medical care. There was no effect on quality-of-life in the total group, whereas the increased survival of sicker patients with at least 3 days of insulin therapy evoked a more compromised perceived quality-of-life, in particular regarding social and family life. The short-term survival benefit obtained with insulin-titrated glycaemic control during intensive care after cardiac surgery was maintained after 4 years, without inducing increased medical care requirements but possibly at the expense of compromised perceived quality of social and family life.