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dc.contributor.authorNam, MCY
dc.contributor.authorMeneses, AL
dc.contributor.authorByrne, CD
dc.contributor.authorRichman, T
dc.contributor.authorQuah, JX
dc.contributor.authorBailey, TG
dc.contributor.authorHickman, I
dc.contributor.authorAnstey, C
dc.contributor.authorAskew, CD
dc.contributor.authorSenior, R
dc.contributor.authorStanton, T
dc.contributor.authorRussell, AW
dc.contributor.authorGreaves, K
dc.date.accessioned2020-05-06T03:47:39Z
dc.date.available2020-05-06T03:47:39Z
dc.date.issued2020
dc.identifier.issn0894-7317
dc.identifier.doi10.1016/j.echo.2020.01.010
dc.identifier.urihttp://hdl.handle.net/10072/393624
dc.description.abstractBackground: Incomplete restoration of myocardial blood flow (MBF) is reported in up to 30% of ST-segment elevation myocardial infarction (STEMI) despite prompt mechanical revascularization. Experimental hyperinsulinemic euglycemia (HE) increases MBF reserve (MBFR). If fully exploited, this effect may also improve MBF to ischemic myocardium. Using insulin-dextrose infusions to induce HE, we conducted four experiments to determine (1) how insulin infusion duration, dose, and presence of insulin resistance affect MBFR response; and (2) the effect of an insulin-dextrose infusion given immediately following revascularization of STEMI on myocardial perfusion. Methods: The MBFR was determined using myocardial contrast echocardiography. Experiment 1 (insulin duration): 12 participants received an insulin-dextrose or saline infusion for 120 minutes. MBFR was measured at four time intervals during infusion. Experiment 2 (insulin dose): 22 participants received one of three insulin doses (0.5, 1.5, 3.0 mU/kg/minute) for 60 minutes. Baseline and 60-minute MBFRs were determined. Experiment 3 (insulin resistance): five metabolic syndrome and six type 2 diabetes (T2DM) participants received 1.5 mU/kg/minute of insulin-dextrose for 60 minutes. Baseline and 60-minute MBFRs were determined. Experiment 4 (STEMI): following revascularization for STEMI, 20 patients were randomized to receive either 1.5 mU/kg/minute insulin-dextrose infusion for 120 minutes or standard care. Myocardial contrast echocardiography was performed at four time intervals to quantify percentage contrast defect length. Results: Experiment 1: MBFR increased with time through to 120 minutes in the insulin-dextrose group and did not change in controls. Experiment 2: compared with baseline, MBFR increased in the 1.5 (2.42 ± 0.39 to 3.25 ± 0.77, P = .002), did not change in the 0.5, and decreased in the 3.0 (2.64 ± 0.25 to 2.16 ± 0.33, P = .02) mU/kg/minute groups. Experiment 3: compared with baseline, MBFR increase was only borderline significant in metabolic syndrome and T2DM participants (1.98 ± 0.33 to 2.59 ± 0.45, P = .04, and 1.67 ± 0.35 to 2.14 ± 0.21, P = .05). Experiment 4: baseline percentage contrast defect length was similar in both groups but with insulin decreased with time and was significantly lower than in controls at 60 minutes (2.8 ± 5.7 vs 13.7 ± 10.6, P = .02). Conclusions: Presence of T2DM, insulin infusion duration, and dose are important determinants of the MBFR response to HE. When given immediately following revascularization for STEMI, insulin-dextrose reduces perfusion defect size at one hour. Hyperinsulinemic euglycemia may improve MBF following ischemia, but further studies are needed to clarify this.
dc.description.peerreviewedYes
dc.languageEnglish
dc.language.isoeng
dc.publisherElsevier
dc.relation.ispartofjournalJournal of the American Society of Echocardiography
dc.subject.fieldofresearchCardiovascular medicine and haematology
dc.subject.fieldofresearchcode3201
dc.titleAn Experimental Series Investigating the Effects of Hyperinsulinemic Euglycemia on Myocardial Blood Flow Reserve in Healthy Individuals and on Myocardial Perfusion Defect Size following ST-Segment Elevation Myocardial Infarction
dc.typeJournal article
dc.type.descriptionC1 - Articles
dcterms.bibliographicCitationNam, MCY; Meneses, AL; Byrne, CD; Richman, T; Quah, JX; Bailey, TG; Hickman, I; Anstey, C; Askew, CD; Senior, R; Stanton, T; Russell, AW; Greaves, K, An Experimental Series Investigating the Effects of Hyperinsulinemic Euglycemia on Myocardial Blood Flow Reserve in Healthy Individuals and on Myocardial Perfusion Defect Size following ST-Segment Elevation Myocardial Infarction, Journal of the American Society of Echocardiography, 2020
dc.date.updated2020-05-06T03:10:17Z
gro.description.notepublicThis publication was entered as an advanced online version.
gro.hasfulltextNo Full Text
gro.griffith.authorAnstey, Chris


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