Effect of adenosine stimulation on global longitudinal strain and mechanical dispersion in the sub-acute phase of ST-segment elevation myocardial infarction.

To evaluate potential effects of adenosine (ADO) administration on global longitudinal strain (GLS) and mechanical dispersion (MD) in ST-segment elevation myocardial infarction (STEMI), as ischemia-reperfusion injury may be reduced by ADO. At 7 ± 2 days after successfully treated STEMI, 49 patients (age 63 ± 11 years, 35 male) underwent rest/stress echocardiography by intravenous administration of ADO at 140 mcg/Kg/minute for 90 s. Resting echocardiography was repeated after 6-months. Thirty sex and age-matched subjects were considered as controls to set normal response of GLS and MD to ADO. GLS and MD were assessed in all time points. Contractile recovery at follow-up was defined by GLS values ≥ 20% at 6 months after STEMI. At baseline, resting GLS was lower (p < 0.001) and MD greater (p < 0.001) in patients than controls. In patients, ADO administration reduced MD (p < 0.001 vs. rest), without effect on GLS, while opposite response was found in controls. In STEMI, both GLS and MD significantly improved at follow-up, compared to baseline (20 ± 3 vs. 17 ± 4%, p < 0.001; 36 ± 9 vs. 46 ± 31 msec, p = 0.030, respectively). Resting MD ≤ 41.9 msec or stress MD ≤ 17.7 msec, resting GLS ≥ 16.5% and troponin peak ≤ 117 ng/mL at baseline predicted contractile recovery at follow-up (AUC 0.745, 0.742, 0.768 and 0.801, respectively, p < 0.0.05 for all). In the sub-acute phase of first optimally treated STEMI, ADO improves MD but not GLS. Both GLS and MD improve at follow-up. Lower is rest or stress MD at baseline, greater is GLS at follow-up.