Prehospital delay ups risk of all-cause mortality in NSTEMI

In patients with non‒ST-segment elevation myocardial infarction (NSTEMI), prehospital delay appears to increase their risk of 3-year all-cause mortality, a study has shown.

A total of 13,104 patients were identified from the Korea-Acute-Myocardial-Infarction-Registry National Institutes of Health, of whom 6,544 with NSTEMI were evaluated. The authors categorized participants into two groups according to symptom-to-door (StD) time (<24 or ≥24 hours); 1,827 (27.9 percent) were classified into the StD time ≥24 hours group.

The primary outcome was 3-year all-cause mortality, while the secondary one was 3-year composite of all-cause mortality, recurrent MI, and hospitalization for heart failure.

All-cause mortality was higher in the StD time ≥24 hours group (17.0 percent vs 10.5 percent; p<0.001), as well as the incidence of secondary outcomes (23.3 percent vs 15.7 percent; p<0.001), compared with the StD time <24 hours group.

There was consistent higher all-cause mortality in the StD time ≥24 hours group in subgroup analysis as regards age, sex, atypical chest pain, dyspnoea, Q-wave in electrocardiogram, use of emergency medical services, hypertension, diabetes mellitus, chronic kidney disease, left ventricle dysfunction, TIMI (Thrombolysis In Myocardial Infarction) flow, and the GRACE risk score.

Multivariable analysis revealed the following independent predictors of prehospital delay: older age, women, nonspecific symptoms such as atypical chest pain or dyspnoea, diabetes, and no use of emergency medical services.

“Recently, the number of patients presenting with NSTEMI has reduced, whereas increased mortality was reported,” the authors said. “A plausible explanation for increased mortality was prehospital delay because of patients’ reticence of their symptoms.”