Evolution of fatigue symptoms from 7 to 24 months after survival from cardiac arrest

Abstract Introduction Fatigue is one of the most commonly reported symptoms in the acute period following an out-of-hospital cardiac arrest (OHCA). However, the evolution of these symptoms over time remains poorly understood. Purpose To investigate longitudinal variations of fatigue symptoms in OHCA survivors at the intended assessment time of 7 and 24 months post-OHCA. Methods A prospective analysis of data from a neuropsychological sub-study of the parent Targeted Hypothermia versus Targeted Normothermia after Out-of-Hospital Cardiac Arrest (TTM2) trial at 8 sites in Sweden, Denmark, and the United Kingdom. The self-reported 20-item Multidimensional Fatigue Inventory (MFI-20) was used to assess fatigue. The questionnaire consists of five scales: General fatigue, Physical fatigue, Reduced activity, Reduced motivation, and Mental fatigue. Total scores were calculated for each dimension separately and higher scores indicate greater fatigue symptoms. Results Of 108 OHCA survivors, 81 (75%) who completed the MFI-20 at both 7 and 24 months, were analysed. Most participants (n=71, 88%) were men, and the mean age was 63 ± 10 years. At a group level, there were no significant changes in any of the five scales between 7 and 24 months (Table 1). Person-level showed a large variation in fatigue symptoms between 7 and 24 months for all five scales. In General fatigue, the mean difference (MD) was -0.53 (± 3.16; Figure 1). Only 9/81 (11%) OHCA survivors reported the same level of General fatigue at the two time-points, 45/81 (56%) OHCA survivors reported less General fatigue symptoms, 27/81 (33%) OHCA survivors reported more General fatigue symptoms. The level of fatigue experienced among the OHCA survivors was higher than norm values except for Mental fatigue at 7 months. The MDs were greatest for Physical fatigue (7 months: +2.5; 24 months: +3.5) and Reduced activity (24 months: +2.5). The MDs were least for Reduced motivation (7 months: +0.3; 24 months: +0.2) and Mental fatigue (7 months: 0.0; 24 months: +0.4). Conclusion Among survivors at 7 and 24 months post-OHCA, there were a great variation in fatigue symptoms at an individual level. This long-term follow-up indicates the need of individualized follow-up of fatigue after OHCA. In general, fatigue does not improve over time and hence should have greater focus in clinical settings.