We evaluated the relationship of renal function and ischaemic and bleeding risk as well as the efficacy and safety of ticagrelor in stable patients with prior myocardial infarction (MI). Methods and results Patients with a history of MI 1-3 years prior from PEGASUS-TIMI 54 were stratified based on estimated glomerular filtration rate (eGFR), with <60 mL/min/1.73 m2 pre-specified for analysis of the effect of ticagrelor on the primary efficacy composite of cardiovascular death, MI, or stroke (major adverse cardiovascular events, MACE) and the primary safety endpoint of TIMI major bleeding. Of 20 898 patients, those with eGFR <60 (N = 4849, 23.2%) had a greater risk of MACE at 3 years relative to those without, which remained significant after multivariable adjustment (hazard ratio, HRadj 1.54, 95% confidence interval, CI 1.27-1.85, P < 0.001). The relative risk reduction in MACE with ticagrelor was similar in those with eGFR <60 (ticagrelor pooled vs. placebo: HR 0.81; 95% CI 0.68-0.96) vs. ≥60 (HR 0.88; 95% CI 0.77-1.00, Pinteraction = 0.44). However, due to the greater absolute risk in the former group, the absolute risk reduction with ticagrelor was higher: 2.7 vs. 0.63%. Bleeding tended to occur more frequently in patients with renal dysfunction. The absolute increase in TIMI major bleeding with ticagrelor was similar in those with and without eGFR <60 (1.19 vs. 1.43%), whereas the excess of minor bleeding tended to be more pronounced (1.93 vs. 0.69%). Conclusion In patients with a history of MI, patients with renal dysfunction are at increased risk of MACE and consequently experience a particularly robust absolute risk reduction with long-term treatment with ticagrelor.