Guideline-indicated treatments and diagnostics, GRACE risk score, and survival for non-ST elevation myocardial infarction

Aim: To investigate whether improved survival from NSTEMI, according to GRACE risk score, was associated with guideline-indicated treatments and diagnostics, and persisted after hospital discharge.

Methods and results: National cohort study (n=389,507 patients, n=232 hospitals, MINAP registry), 2003-13. The primary outcome was adjusted all-cause survival estimated using flexible parametric survival modelling with time-varying covariates over a median follow-up of 2.3-years. Receipt of all eligible treatments (optimal care) was inversely related to risk status: 25.6% in low, 18.6% in intermediate and 11.5% in high risk NSTEMI. At 30 days, the use of optimal care was associated with improved survival among high (adjusted hazard ratio [aHR]=0.66 [95% CI 0.53-0.86], difference in absolute mortality rate per 100 patients [AMR/100] –0.19 [95% CI –0.29 to –0.08]), and intermediate (aHR=0.74 [95% CI 0.62-0.92]; AMR/100 –0.15 [95% CI –0.23 to –0.08]) risk NSTEMI. At the end of follow-up (8.4 years), the significant association between the use of all eligible guideline-indicated treatments and improved survival remained only for high risk NSTEMI (aHR=0.66 [95% CI 0.50-0.96]; AMR/100= –0.03 [95% CI –0.06 to –0.01]). For low risk NSTEMI, there was no association between the use of optimal care and improved survival at 30 days (aHR=0.92 [95% CI 0.69-1.38] and at 8.4 years (aHR=0.71 [95% CI 0.39-3.74]).

Conclusions: Optimal use of guideline-indicated care for NSTEMI was associated with greater survival gains with increasing GRACE risk, but its use decreased with increasing GRACE risk.