Background Cold stress and subsequent fatty diet reduce infarct size (IS) in the isolated mouse heart when subjected to ischemia and reperfusion. We assessed the hypothesis that Exchange protein directly activated by cyclic adenosine monophosphate 1 (Epac-1) is necessary for cold- and fat stress induced cardioprotection. Methods Epac-1 knock-out mice (-/-) (Epac-1 KO) and wild type littermates (WT) were subjected to cold stress (week 5-9) and a fatty diet (week 10-termination) or control environment with room temperature and normal diet. At age 42-43 weeks the mice were sacrificed and the hearts were excised and mounted on a Langendorff perfusion system. The hearts were subjected to 30 min of global ischemia and 1 h of reperfusion, before IS was measured. Hemodynamic parameters were measured at regular intervals. Results IS is reported as necrotic tissue/left ventricle ± S.E.M. (%). All groups were n≥6, and group differences were tested by one-way ANOVA combined with Fischer’s post-hoc test. WT animals were cardioprotected from cold/fat (WT cold/fat 42±3,5% vs. WT controls 61±6,9%, p<0.05, while Epac-1 KO were not (Epac-1 KO cold/fat 65±9,8% vs. Epac-1 KO ctrl 56±5,5%, ns.). Hemodynamic parameters, such as left ventricle developed pressure (LVDP), also suggests a better recovery of the WT cold/fat group, compared to the other groups. LVDP recovery in % of baseline at 30 min of reperfusion, baseline set at 20 min of stabilization: WT cold/fat 94,8±7,4%, WT ctrl 69,9±8,1%, Epac-1 KO cold/fat 59,8±9,1%, Epac-1 KO ctrl 64,8±6,3% (p<0,05). Conclusion Epac-1 seems to be necessary for the cardioprotective effect of cold stress and fatty diet.