Objective: To determine the impact of subsequent cardiovascular (CV) events on change in preference-based measures of HRQL in patients who previously experienced an acute myocardial infarction using data from the VAlsartan IN Acute Myocardial iNfarcTion (VALIANT) trial. Methods: Patients in the VALIANT HRQL sub-study completed the EQ-5D, including the visual analogue scale (VAS) rescaled to 0-1, at baseline, and 6, 12, 20, and 24 months. All EQ-5D assessments from baseline through the first assessment following a CV event were retained. Patients who experienced multiple events or died prior to the next EQ-5D assessment were excluded from the main analysis. Random-effects regression models, specified with random intercepts and slopes, were used to model linear trajectories of utility weights and VAS scores across time. To evaluate the impact of a CV event (hospitalization for heart failure, recurrent acute myocardial infarction, stroke, and resuscitated sudden death/cardiac arrest), the mean trajectory change between the observed HRQL scores following the CV event and the expected HRQL scores based on the patients' pre-event trajectories were estimated. Results: Among 14,703 adult patients enrolled in VALIANT, 2,556 patients were eligible for HRQL sub-study and completed baseline EQ5D. Among the 504 patients who experienced a nonfatal CV event, the trajectory-adjusted mean change following the event was -0.07 (95%CI: -0.1 to -0.03; P=0.0007) based on UK utility weights, -0.05 (95%CI: -0.08 to -0.01; P=0.0082) based on US utility weights, and -0.06 (95%CI: -0.08 to -0.03; P<0.0001) based on VAS scores. Differences between results using utility weights and VAS scores were most notable for patients suffering a non-fatal stroke with trajectory adjusted mean change scores of -0.26 with UK utility weights, -0.22 with US utility weights, and -0.06 with VAS. Conclusion: Post-MI patients who suffered a subsequent cardiovascular event experienced a significant decrease in HRQL.