Prognostic implications of non-infarct-related territory unrecognized myocardial infarction in patients with non-ST-segment-elevation acute coronary syndrome.

BACKGROUND

Prognostic value of non-infarct-related territory (non-IR) unrecognized myocardial infarction (UMI) in patients with non-ST-elevation acute coronary syndrome (NSTE-ACS) remains to be elucidated. We sought to evaluate the prognostic impact of non-IR UMI in patients with first NSTE-ACS presentation.

METHODS

This retrospective single-center analysis was conducted in patients with NSTE-ACS without prior history of coronary artery disease, who underwent uncomplicated urgent percutaneous coronary intervention (PCI) within 48 h of admission between August 2014 and January 2018. All patients underwent postprocedural cardiac magnetic resonance imaging (CMR) within 30 days after PCI. Non-IR UMI was defined as the presence of non-IR delayed gadolinium enhancement with an ischemic distribution pattern. We investigated the association of non-IR UMI, other CMR findings and baseline clinical characteristics with major adverse cardiac events (MACE), defined as death, non-fatal myocardial infarction, stroke, late revascularization, and hospitalization for congestive heart failure.

RESULTS

A total of 168 NSTE-ACS patients were included [124 men (73.8 %); 66 ± 11 years]. Non-IR UMI was detected in 28 patients (16.7 %). During a median follow-up of 32 (15-58) months, MACE occurred in 10 (35.7 %) patients with non-IR UMI, and 20 (14.3 %) patients without (p = 0.013). Cox's proportional hazards analysis showed that the presence of non-IR UMI was an independent predictor of MACE (hazard ratio [HR], 2.37, 95 % confidence interval [CI], 1.09-5.18, p = 0.030). In patients with NSTE-ACS undergoing urgent PCI, the prevalence of non-IR UMI was 16.7 %.

CONCLUSIONS

Non-IR UMI provided prognostic information independent of conventional risk factors and the extent of myocardial injury caused by NSTE-ACS.