658 Impairment of strain reserve extends to remote myocardium in the sub-acute phase of ST-elevation myocardial infarction

Abstract

Abstract Aims In ST-elevation myocardial infarction (STEMI), subtle tissutal changes in remote myocardium predict long-term left ventricular (LV) remodelling and prognosis, independently of infarct size and microvascular obstruction. Whether there is a subclinical dysfunction of remote myocardium, detectable by longitudinal strain (LS) at echocardiography, and whether it varies in different locations of STEMI and with adenosine (ADO) challenge, is still unknown. Methods and results Fifty-three patients (age 65 ± 12.5 years, 44 male, 20 anterior and 33 non-anterior, P = 0.01) underwent rest/stress echocardiography at 7 ± 2 days after successfully treated STEMI, and at 6-months follow-up. Global LS (GLS), ischaemic and remote LS (iLS and rLS) were analysed in anterior and non-anterior STEMI. Both at rest and at follow-up, GLS was stratified by ejection fraction (EF) into three groups: EF < 40%, 40–49%, and ≥50%. Normal subjects, undergoing ADO stress echo, represented controls. Anterior STEMI showed lower GLS than controls (P < 0.001) and non-anterior STEMI (P < 0.001). ADO increased GLS in controls (P = 0.05), but neither in anterior nor in non-anterior STEMI, GLS changed during ADO stress, although significantly improved at follow-up (P < 0.001 and P = 0.002, respectively). In anterior STEMI, rLS was comparable to iLS at rest, during stress and at follow-up (P = ns), while in non-anterior STEMI rLS was higher than iLS throughout the study (P < 0.001). Patients with EF < 40% and 40–49% had similar values of GLS, iLS, and rLS, which were, both at rest and at follow-up, lower than those of patients with EF ≥ 50% (P < 0.001). Conclusions In the subacute phase, anterior STEMI shows the worst impairment of LS in both ischaemic and remote regions. Strain reserve to ADO is absent in remote myocardium, as well as in ischaemic zone, regardless of MI location. Global, ischaemic and remote LS may improve at follow-up.