Heart failure in survivors of out-of-hospital cardiac arrest – factors associated with reduced systolic ventricular function at follow-up

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Abstract Background Survival after out-of-hospital cardiac arrest (OHCA) has increased in recent years but is still only 10%. Little is known about the association between post-resuscitation comorbidity and heart failure after discharge from the initial OHCA-admission. Purpose In OHCA-survivors we aimed to describe predictors of left ventricular (LV) dysfunction, defined as LV ejection fraction (LVEF) <40%, at follow-up. Methods A consecutive cohort of OHCA-patients with cardiac cause from 2007 to 2011 without a pre-OHCA congestive heart failure diagnosis (according to the Danish National Patient Registry, which holds data on all Danish citizens) were retrospectively examined. Logistic regression analyses were used to assess factors associated with LV dysfunction (LVEF <40%) at follow-up after a median of 6 months. Follow-up was not performed systematically in the OHCA-survivors and data from follow-up was assessed by reading of patient charts. Results A total of 365 OHCA-survivors with a mean age of 61 years were discharged alive from hospital. LVEF <40% at hospital discharge was seen in 54% (n=184, 7% missing), and at follow-up after a median of 6 months 19% (n=69) of the total OHCA-cohort of survivors still had LV dysfunction. Factors associated with LV dysfunction at follow-up were chronic ischemic heart disease (IHD) prior to OHCA (odds ratio (OR) = 2.9 (95% CI: 1.2 – 7.1)) and ST-elevation myocardial infarction (STEMI) as cause of OHCA (OR = 2.9 (1.4–6.0)), whereas age, gender, high comorbidity burden prior to OHCA or pre-hospital circumstances (including shockable cardiac arrest rhythm) were not. Conclusion More than half of OHCA-survivors with LVEF <40% at hospital discharge improved LV function and LV dysfunction at follow-up after a median of 6 months after discharge was present in 1 in 5 (19%) of the cohort. Chronic IHD and STEMI were the only factors significantly associated with LV dysfunction at follow-up. A systematic follow-up including echocardiography in the outpatient clinic for OHCA-survivors is recommended especially in patients with reduced LV function at discharge and in STEMI-patients in order to assess the appropriateness of heart failure medication and an implantable cardiac defibrillator. Funding Acknowledgement Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): Danish Foundation Trygfonden