Impact of cardiovascular events on change in quality of life and utilities in patients after myocardial infarction: a VALIANT study (valsartan in acute myocardial infarction)

Abstract

Objectives: The objective of this study was to determine the impact of nonfatal cardiovascular (CV) events on changes in health-related quality of life (HRQL).

Background: There is limited understanding of the impact of nonfatal CV events on long-term changes in HRQL in survivors of myocardial infarction (MI).

Methods: The VALIANT (Valsartan In Acute Myocardial Infarction) trial enrolled 14,703 patients post-MI complicated by Killip class II or higher (scale measuring heart failure severity post-MI ranging from class I to IV) and/or reduced ejection fraction. The HRQL substudy included 2,556 (17.4%) patients who completed the EQ-5D with 5 questions, with responses mapped to utility weight on a scale of 0 to 1 and a visual analog scale (VAS) ranging from 0 (worst) to 100 (best) imaginable health state. EQ-5D was administered at baseline and 6, 12, 20, and 24 months. The trajectory of EQ-5D scores was developed by using linear mixed effects regression models with calculation of deviation from this trajectory after nonfatal CV events. Patients who died before the next EQ-5D assessment were excluded.

Results: Over a 2-year period, 597 patients experienced a nonfatal CV event and survived to have another EQ-5D assessment. Their baseline EQ-5D scores were lower than patients without a subsequent nonfatal CV event (VAS 61.0 ± 19 vs 68.2 ± 18 [p < 0.001] and US-based utility score 0.76 ± 0.22 vs 0.83 ± 0.17 [p < 0.001]). These patients with CV events experienced a trajectory-adjusted 6.6 point decrease (p < 0.001) in VAS scores and a 0.07 decrease (p < 0.001) in utility score after the nonfatal CV event.

Conclusions: MI survivors suffering a CV event experienced significantly worse HRQL than their previous trajectory, suggesting that generic instruments can be responsive to nonfatal events. Reduction in nonfatal CV events may affect longitudinal changes in HRQL.

Keywords: heart failure; myocardial infarction; quality of life; utility.