Association of baseline and changes in health related quality of life with mortality following myocardial infarction: multicentre longitudinal linked cohort study

Abstract Background/Introduction Health related quality of life (HRQoL) for patients following myocardial infarction (MI) is frequently impaired and often deteriorates. However, the association between HRQoL and clinical endpoints in patients with MI is unknown.

Purpose To investigate the association of baseline and temporal changes in HRQoL with long term all-cause mortality following MI.

Methods This nationwide longitudinal linked health record study includes individuals with MI admitted to 77 hospitals in England between 1st November 2011 and 24th June 2015 in the EMMACE-3 and -4 studies. Self-reported HRQoL was collected using the EuroQol EQ-5D-3L (EuroQOL Visual Analogue Scale (EQ-VAS) and EuroQOL 5-Dimensional Classification (EQ-5D)) instrument during hospitalisation and at 1, 6 and 12-months following hospital discharge. Flexible parametric and multilevel survival models estimated associations of baseline and change in HRQoL with long term all-cause mortality.

Results Of 9,474 individuals with MI, 25% (2,360) were women and 22.5% (2,135) participants died during the 9 years follow up period (median 6.9 years). There was an improvement in HRQoL over 12 months following MI (baseline mean, mean increase: EQ-5D 0.76, 0.003 per month; EQVAS 69.0, 0.5 per month). Better HRQoL at baseline was inversely associated with mortality (HR 0.55, 95% CI 0.47-0.63) (Figure 1A). At baseline, problems with self-care (HR 1.73, 95% CI 1.56-1.92), mobility (1.65, 1.50-1.81), usual activities (1.34, 1.23-1.47) and pain/discomfort (1.34, 1.22-1.46), were associated with increased mortality (Figure 1A). Improvements in EQ-5D (HR 0.69, 95% CI 0.60-0.80), but not EQ-VAS reduced the risk of death (Figure 1B). Deterioration in mobility, pain/discomfort, usual activities and self-care over 12 months increased the risk of death (HR 1.43, 95% CI 1.31-1.58; 1.21, 95% CI 1.11-1.32; 1.20, 95% CI 1.10-1.32; 1.44, 95% CI 1.30-1.59, respectively) (Figure 1B).

Conclusions For patients with MI, poor HRQoL at baseline, its dimensions and deterioration over time are associated with mortality. Measuring HRQoL in routine clinical practice could delineate an at-risk group for targeted interventions to improve prognosis.