Remote Ischemic Conditioning in Patients With Myocardial Infarction Treated With Primary Angioplasty: Impact on Left Ventricular Function Assessed by Comprehensive Echocardiography and Gated Single-Photon Emission CT
Kim Munk;Niels Andersen;Michael Schmidt;Soren Nielsen;Christian Terkelsen;Erik Sloth;Hans Bøtker;Torsten Nielsen;Steen Poulsen;
From the Department of Cardiology (K.M., N.H.A., M.R.S., C.J.T., H.E.B., T.T.N., S.H.P.), Department of Nuclear Medicine (S.S.N.), and Department of Anesthesia & Intensive Care Medicine (E.S.), Aarhus University Hospital Skejby, DK-8200 Aarhus N, Denmark.
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Background—We have found that remote ischemic conditioning (rIC), adjunctive to primary angioplasty, increases myocardial salvage in patients with ST-segment elevation myocardial infarction (STEMI) and extensive myocardial area at risk (AAR). The present substudy aimed to evaluate the short-term effects of rIC on left ventricular (LV) function.Methods and Results—Patients with a first STEMI were randomized to rIC (4 cycles of 5 minutes upper-limb ischemia) during transfer to primary percutaneous coronary intervention (pPCI) (n=123) versus pPCI alone (n=119). Ejection fraction (EF), LV volumes, (2D and 3D echocardiography and myocardial perfusion imaging), and speckle-tracking global longitudinal strain were compared between treatment groups. There was no significant difference in LV function at day 1 (EF-2D, 0.51±0.10 versus 0.49±0.10; P=0.22) and after 30 days (EF-2D, 0.54±0.08 versus 0.53±0.10) between the rIC and the pPCI-alone groups. In patients with extensive AAR ≥35% of LV (n=53), EF after 30 days was higher after rIC than after pPCI alone (EF-2D, 0.51±0.07 versus 0.46±0.09; P=0.05). In patients with anterior infarction (n=97), rIC preserved LV function on day 1 (EF-2D, 0.51±0.11 versus 0.46±0.11; P=0.03) and persistently after 30 days (EF-2D, 0.55±0.08 versus 0.50±0.11; P=0.04; EF-myocardial perfusion imaging, 0.55±0.10 versus 0.49±0.12; P=0.02). These patients had similar AAR, whereas rIC reduced infarct size from 16% to 7% of LV (P=0.01).Conclusions—Although no significant overall effect was observed, rIC seemed to result in modest improvement in LV function in high-risk patients prone to develop large myocardial infarcts. These results need to be confirmed in larger trials.Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00435266.