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- Erlinge, David, et al.
(författare)
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Therapeutic Hypothermia for the Treatment of Acute Myocardial Infarction-Combined Analysis of the RAPID MI-ICE and the CHILL-MI Trials
- 2015
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Ingår i: Therapeutic Hypothermia and Temperature Management. - : Mary Ann Liebert Inc. - 2153-7658 .- 2153-7933. ; 5:2, s. 77-84
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Tidskriftsartikel (refereegranskat)abstract
- In the randomized rapid intravascular cooling in myocardial infarction as adjunctive to percutaneous coronary intervention (RAPID MI-ICE) and rapid endovascular catheter core cooling combined with cold saline as an adjunct to percutaneous coronary intervention for the treatment of acute myocardial infarction CHILL-MI studies, hypothermia was rapidly induced in conscious patients with ST-elevation myocardial infarction (STEMI) by a combination of cold saline and endovascular cooling. Twenty patients in RAPID MI-ICE and 120 in CHILL-MI with large STEMIs, scheduled for primary percutaneous coronary intervention (PCI) within <6 hours after symptom onset were randomized to hypothermia induced by rapid infusion of 600-2000mL cold saline combined with endovascular cooling or standard of care. Hypothermia was initiated before PCI and continued for 1-3 hours after reperfusion aiming at a target temperature of 33 degrees C. The primary endpoint was myocardial infarct size (IS) as a percentage of myocardium at risk (IS/MaR) assessed by cardiac magnetic resonance imaging at 4 +/- 2 days. Patients randomized to hypothermia treatment achieved a mean core body temperature of 34.7 degrees C before reperfusion. Although significance was not achieved in CHILL-MI, in the pooled analysis IS/MaR was reduced in the hypothermia group, relative reduction (RR) 15% (40.5, 28.0-57.6 vs. 46.6, 36.8-63.8, p=0.046, median, interquartile range [IQR]). IS/MaR was predominantly reduced in early anterior STEMI (0-4h) in the hypothermia group, RR=31% (40.5, 28.8-51.9 vs. 59.0, 45.0-67.8, p=0.01, median, IQR). There was no mortality in either group. The incidence of heart failure was reduced in the hypothermia group (2 vs. 11, p=0.009). Patients with large MaR (>30% of the left ventricle) exhibited significantly reduced IS/MaR in the hypothermia group (40.5, 27.0-57.6 vs. 55.1, 41.1-64.4, median, IQR; hypothermia n=42 vs. control n=37, p=0.03), while patients with MaR<30% did not show effect of hypothermia (35.8, 28.3-57.5 vs. 38.4, 27.4-59.7, median, IQR; hypothermia n=15 vs. control n=19, p=0.50). The prespecified pooled analysis of RAPID MI-ICE and CHILL-MI indicates a reduction of myocardial IS and reduction in heart failure by 1-3 hours with endovascular cooling in association with primary PCI of acute STEMI predominantly in patients with large area of myocardium at risk. (ClinicalTrials.gov id NCT00417638 and NCT01379261).
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- Götberg, Matthias, et al.
(författare)
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A Pilot Study of Rapid Cooling by Cold Saline and Endovascular Cooling Before Reperfusion in Patients With ST-Elevation Myocardial Infarction.
- 2010
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Ingår i: Circulation. Cardiovascular Interventions. - 1941-7632. ; 3, s. 400-407
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Tidskriftsartikel (refereegranskat)abstract
- Background-Experimental studies have shown that induction of hypothermia before reperfusion of acute coronary occlusion reduces infarct size. Previous clinical studies, however, have not been able to show this effect, which is believed to be mainly because therapeutic temperature was not reached before reperfusion in the majority of the patients. We aimed to evaluate the safety and feasibility of rapidly induced hypothermia by infusion of cold saline and endovascular cooling catheter before reperfusion in patients with acute myocardial infarction. METHODS AND RESULTS: =0.12). Despite similar duration of ischemia (174+/-51 minutes versus 174+/-62 minutes, hypothermia versus control, P=1.00), infarct size normalized to myocardium at risk was reduced by 38% in the hypothermia group compared with the control group (29.8+/-12.6% versus 48.0+/-21.6%, P=0.041). This was supported by a significant decrease in both peak and cumulative release of Troponin T in the hypothermia group (P=0.01 and P=0.03, respectively). Conclusions-The protocol demonstrates the ability to reach a core body temperature of <35 degrees C before reperfusion in all patients without delaying primary percutaneous coronary intervention and that combination hypothermia as an adjunct therapy in acute myocardial infarction may reduce infarct size at 3 days as measured by MRI. Clinical Trial Registration-URL: http://clinicaltrials.gov. Unique identifier: NCT00417638.
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- Götberg, Matthias, et al.
(författare)
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Optimal timing of hypothermia in relation to myocardial reperfusion.
- 2011
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Ingår i: Basic Research in Cardiology. - : Springer Science and Business Media LLC. - 1435-1803 .- 0300-8428. ; 106, s. 697-708
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Tidskriftsartikel (refereegranskat)abstract
- Two previous clinical trials investigating hypothermia as an adjunct therapy for myocardial infarction have failed. Recently a pilot study has demonstrated a significant reduction in infarct size. The aims of this study were to elucidate the effects of hypothermia on reperfusion injury and to investigate the optimal hypothermia protocol for a future clinical trial. Pigs (40-50 kg) were anesthetized and a normal pig temperature of 38°C was established utilizing an endovascular temperature modulating catheter. The pigs were randomized to a combination hypothermia group (1,000 ml of 4°C saline solution and endovascular cooling, n = 8), or to normothermic controls (n = 8). A PCI balloon was then inflated in the LAD for 40 min (control) or 45 min with hypothermia induced during the last 5 min. Furthermore, hypothermia induced by cold saline alone (n = 8), and prolonged combination hypothermia during reperfusion (n = 7) were also examined. Infarct size and area at risk were determined ex vivo after 4 h of reperfusion using gadolinium-enhanced MRI and Tc-99-tetrofosmin SPECT, respectively. All pigs in the combination hypothermia group were cooled to <35°C within 5 min. Combination hypothermia reduced IS/AAR by 18% compared with normothermic controls despite 5 min longer ischemic time (61 ± 5 vs. 74 ± 4%, p = 0.03). Cold saline did not reduce IS/AAR. Prolonging hypothermia treatment after onset of reperfusion by an additional 45 min over that used in a previous paper did not confer any additional benefit. The cardioprotective effects of hypothermia treatment are due to an attenuation of myocardial injury during both ischemia and reperfusion. The results suggest that a hypothermia protocol using a cold saline infusion and endovascular cooling enables hypothermia to be induced in a clinical setting without delaying reperfusion therapy.
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- Götberg, Matthias, et al.
(författare)
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Rapid short-duration hypothermia with cold saline and endovascular cooling before reperfusion reduces microvascular obstruction and myocardial infarct size.
- 2008
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Ingår i: BMC Cardiovascular Disorders. - : Springer Science and Business Media LLC. - 1471-2261. ; 8:Apr 10
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: The aim of this study was to evaluate the combination of a rapid intravenous infusion of cold saline and endovascular hypothermia in a closed chest pig infarct model. METHODS: Pigs were randomized to pre-reperfusion hypothermia (n = 7), post-reperfusion hypothermia (n = 7) or normothermia (n = 5). A percutaneous coronary intervention balloon was inflated in the left anterior descending artery for 40 min. Hypothermia was started after 25 min of ischemia or immediately after reperfusion by infusion of 1000 ml of 4 degrees C saline and endovascular hypothermia. Area at risk was evaluated by in vivo SPECT. Infarct size was evaluated by ex vivo MRI. RESULTS: Pre-reperfusion hypothermia reduced infarct size/area at risk by 43% (46 +/- 8%) compared to post-reperfusion hypothermia (80 +/- 6%, p < 0.05) and by 39% compared to normothermia (75 +/- 5%, p < 0.05). Pre-reperfusion hypothermia infarctions were patchier in appearance with scattered islands of viable myocardium. Pre-reperfusion hypothermia abolished (0%, p < 0.001), and post-reperfusion hypothermia significantly reduced microvascular obstruction (10.3 +/- 5%; p < 0.05), compared to normothermia: (30.2 +/- 5%). CONCLUSION: Rapid hypothermia with cold saline and endovascular cooling before reperfusion reduces myocardial infarct size and microvascular obstruction. A novel finding is that hypothermia at the onset of reperfusion reduces microvascular obstruction without reducing myocardial infarct size. Intravenous administration of cold saline combined with endovascular hypothermia provides a method for a rapid induction of hypothermia suggesting a potential clinical application.
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- Heiberg, Einar, et al.
(författare)
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Automated quantification of myocardial infarction from MR images by accounting for partial volume effects: animal, phantom, and human study.
- 2008
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Ingår i: Radiology. - : Radiological Society of North America (RSNA). - 1527-1315 .- 0033-8419. ; 246:2, s. 581-588
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Tidskriftsartikel (refereegranskat)abstract
- Ethics committees approved human and animal study components; informed written consent was provided (prospective human study [20 men; mean age, 62 years]) or waived (retrospective human study [16 men, four women; mean age, 59 years]). The purpose of this study was to prospectively evaluate a clinically applicable method, accounting for the partial volume effect, to automatically quantify myocardial infarction from delayed contrast material-enhanced magnetic resonance images. Pixels were weighted according to signal intensity to calculate infarct fraction for each pixel. Mean bias +/- variability (or standard deviation), expressed as percentage left ventricular myocardium (%LVM), were -0.3 +/- 1.3 (animals), -1.2 +/- 1.7 (phantoms), and 0.3 +/- 2.7 (patients), respectively. Algorithm had lower variability than dichotomous approach (2.7 vs 7.7 %LVM, P < .01) and did not differ from interobserver variability for bias (P = .31) or variability (P = .38). The weighted approach provides automatic quantification of myocardial infarction with higher accuracy and lower variability than a dichotomous algorithm.
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| 8. |
- Ugander, Martin, et al.
(författare)
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Pulmonary blood volume variation decreases after myocardial infarction in pigs: a quantitative and noninvasive MR imaging measure of heart failure.
- 2010
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Ingår i: Radiology. - : Radiological Society of North America (RSNA). - 1527-1315 .- 0033-8419. ; 256:2, s. 415-423
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To prospectively evaluate the usefulness of magnetic resonance (MR) imaging for estimating pulmonary blood volume (PBV) and the variation in PBV throughout the cardiac cycle in experimental heart failure. MATERIALS AND METHODS: The animal care committee approved this prospective study. Seven pigs were studied before and after myocardial infarction. PBV measurement was validated in a phantom and calculated as the product of cardiac output determined with velocity-encoded MR imaging and the pulmonary transit time for an intravenous bolus of contrast material to pass through the pulmonary circulation. The difference in arterial and venous pulmonary flow during the cardiac cycle was integrated for calculation of the PBV variation (expressed as percentage of stroke volume). Differences were evaluated with the Wilcoxon test. RESULTS: Calculated and direct phantom measurements of PBV differed by a mean of 4% +/- 3 (standard deviation) (R(2) = 0.97, P < .001). Infarction induced a decrease in left ventricular stroke volume (44 mL +/- 6 vs 27 mL +/- 7; P = .02), ejection fraction (55% +/- 5 vs 41% +/- 4; P = .02), and PBV variation (61% +/- 12 vs 43% +/- 15; P = .04) but not PBV (225 mL +/- 23 vs 211 mL +/- 42; P = .50). The mean pulmonary artery pressure increased after infarction (19 mm Hg +/- 6 vs 27 mm Hg +/- 4; P = .04). CONCLUSION: Following infarction, the PBV variation but not PBV decreased. PBV variation was the noninvasive measure exhibiting the greatest percentage of change following infarction. MR imaging can be used to assess the variation of the PBV during the cardiac cycle as a marker of heart failure.
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