Kardiale MRT zur Quantifizierung der mikrovaskulären Obstruktion beim akuten Myokardinfarkt

Zusammenfassung

Ziel: Auftreten und Ausdehnung einer mikrovaskulären Obstruktion (MO) sind neben der Infarktausdehnung wichtige prognostische Faktoren beim akuten Herzinfarkt. Ziel der vorliegenden Studie war es, den Einfluss des zeitlichen Abstands zwischen KM-Injektion und Bildakquisition auf die gemessene MO- und Infarktausdehnung zu untersuchen. Material und Methoden: 50 Patienten mit akutem Myokardinfarkt (40 Männer, mittleres Alter 58,1 ± 11,7 Jahre), die nach perkutaner Revaskularisation einen Grad-3-Fluss nach der Thrombolysis-In-Myocardial-Infarction-Klassifikation im Infarktgefäß aufwiesen, wurden innerhalb von 5 Tagen nach Infarkt an einem 1,5 T-MRT untersucht. 2, 5, 10 und 20 min nach Injektion von 0,2 mmol Gadodiamid (Omniscan®, GE Healthcare Buchler) wurde eine Single-Shot-IR-SSFP-Sequenz (TR 2,4 ms, TE 1,08 ms, TI 180 – 280 ms, FA 50°) akquiriert, welche den gesamten linken Ventrikel innerhalb eines Atemstillstands abdeckte. Infarktgrößen sowie Ausdehnung der MO wurden für jeden Zeitpunkt bestimmt. Ergebnisse: Eine MO konnte 2 min nach KM-Injektion (p. i.) bei 32 Patienten nachgewiesen werden, während 20 min p. i. nur bei 23 Patienten eine MO nachweisbar war (p = 0,002). Bei allen Patienten mit MO nahm die Größe der MO-Zone über die Zeit ab (7,3 ± 8,9 % der LV-Muskelmasse 2 min p. i. vs. 2,4 ± 4,6 % 20 min p. i. p < 0,0001). Die ermittelten Infarktgrößen stiegen von 13,9 ± 13,5 % der LV-Muskelmasse 2 min p. i. auf 18,6 ± 14,2 % 10 min p. i. (p < 0,0001) und blieben danach unverändert (18,7 ± 14,3 % 20 min p. i.; p = 0,57). Schlussfolgerung: Unsere Studie belegt, dass die zeitliche Latenz zwischen KM-Gabe und Bildakquisition einen signifikanten Einfluss auf die abgrenzbare No-Reflow- und Infarktgröße hat.

Abstract

Purpose: Microvascular obstruction (MO) and the extent of infarction are important prognostic factors in acute myocardial infarction. Our study aimed to investigate the effect of the time interval between contrast administration and image acquisition on the quantification of microvascular obstruction and myocardial infarction. Materials and Methods: 50 consecutive patients with acute myocardial infarction (40 male, mean age 58.1 ± 11.7 years) treated by percutaneous coronary revascularization resulting in a grade 3 flow according to the thrombolysis in myocardial infarction flow classification were examined on a 1.5 T MR scanner within the first 5 days after infarction. 2, 5, 10, and 20 minutes after I.V. administration of 0.2 mmol/kg per kg body weight of Gadodiamid (Omniscan^TM, GE Healthcare Buchler, Germany), a single shot IR-SSFP sequence (TR 2.4 ms, TE 1.08 ms, TI 180 – 280 ms, FA 50°) covering the entire left ventricle was acquired. Areas of MO and myocardial infarction were measured for all times after contrast injection (p. i.). Results: MO was detected in 32 of 50 patients two minutes p. i., while 23 patients showed evidence of MO (p = 0.002) 20 min. p. i. In all patients with MO, the extent of MO decreased over time (7.4 ± 9.0 % of the LV myocardium 2 min. p. i. vs. 2.4 ± 4.6 % 20 min. p. i. p < 0.0001). The area of myocardial infarction increased from 13.9 ± 13.5 % 2 min. p. i. to 18.6 ± 14.2 % 10 min. p. i. (p < 0.0001), and then remained unchanged (18.7 ± 14.3 % at 20 min. p = 0.57). Conclusion: Our study shows that the time delay between contrast media injection and image acquisition has a significant impact on the delimitable extent of MO and infarct size.

Key words

acute myocardial infarction - microvascular obstruction - no reflow - CMR - late enhancement

Literatur

• 1 Kloner R A, Ganote C E, Jennings R B. The ”no-reflow” phenomenon after temporary coronary occlusion in the dog.  J Clin Invest. 1974;  54 1496-1508
• 2 Ambrosio G, Weisman H F, Mannisi J A. et al . Progressive impairment of regional myocardial perfusion after initial restoration of postischemic blood flow.  Circulation. 1989;  80 1846-1861
• 3 Wu K C, Zerhouni E A, Judd R M. et al . Prognostic significance of microvascular obstruction by magnetic resonance imaging in patients with acute myocardial infarction.  Circulation. 1998;  97 765-772
• 4 Abbo K M, Dooris M, Glazier S. et al . Features and outcome of no-reflow after percutaneous coronary intervention.  Am J Cardiol. 1995;  75 778-782
• 5 Hombach V, Grebe O, Merkle N. et al . Sequelae of acute myocardial infarction regarding cardiac structure and function and their prognostic significance as assessed by magnetic resonance imaging.  Eur Heart J. 2005;  26 549-557
• 6 Nijveldt R, Beek A M, Hirsch A. et al . Functional recovery after acute myocardial infarction: comparison between angiography, electrocardiography, and cardiovascular magnetic resonance measures of microvascular injury.  J Am Coll Cardiol. 2008;  52 181-189
• 7 Bruder O, Breuckmann F, Jensen C. et al . Prognostic impact of contrast-enhanced CMR early after acute ST segment elevation myocardial infarction (STEMI) in a regional STEMI network: results of the ”Herzinfarktverbund Essen”.  Herz. 2008;  33 136-142
• 8 Hunold P, Brandt-Mainz K, Freudenberg L. et al . Myokardiale vitalitätsdiagnostik mit kontrastverstärkter Magnetresonanztomographie – Vergleich des „late enhancement”-Konzepts mit der Positionen-Emissions-Tomographie.  Fortschr Röntgenstr. 2002;  174 867-873
• 9 Wagner A, Mahrholdt H, Holly T A. et al . Contrast-enhanced MRI and routine single photon emission computed tomography (SPECT) perfusion imaging for detection of subendocardial myocardial infarcts: an imaging study.  Lancet. 2003;  361 374-379
• 10 Kim R J, Wu E, Rafael A. et al . The use of contrast-enhanced magnetic resonance imaging to identify reversible myocardial dysfunction.  N Engl J Med. 2000;  343 1445-1453
• 11 Beek A M, Kuhl H P, Bondarenko O. et al . Delayed contrast-enhanced magnetic resonance imaging for the prediction of regional functional improvement after acute myocardial infarction.  J Am Coll Cardiol. 2003;  42 895-901
• 12 Wu K C, Kim R J, Bluemke D A. et al . Quantification and time course of microvascular obstruction by contrast-enhanced echocardiography and magnetic resonance imaging following acute myocardial infarction and reperfusion.  J Am Coll Cardiol. 1998;  32 1756-1764
• 13 Lund G K, Stork A, Saeed M. et al . Acute myocardial infarction: evaluation with first-pass enhancement and delayed enhancement MR imaging compared with 201Tl SPECT imaging.  Radiology. 2004;  232 49-57
• 14 Yan A T, Gibson C M, Larose E. et al . Characterization of microvascular dysfunction after acute myocardial infarction by cardiovascular magnetic resonance first-pass perfusion and late gadolinium enhancement imaging.  J Cardiovasc Magn Reson. 2006;  8 831-837
• 15 Lund G K, Stork A, Muellerleile K. et al . Prediction of left ventricular remodeling and analysis of infarct resorption in patients with reperfused myocardial infarcts by using contrast-enhanced MR imaging.  Radiology. 2007;  245 95-102
• 16 Gerber B L, Rochitte C E, Melin J A. et al . Microvascular obstruction and left ventricular remodeling early after acute myocardial infarction.  Circulation. 2000;  101 2734-2741
• 17 Gibson C M, Schomig A. Coronary and myocardial angiography: angiographic assessment of both epicardial and myocardial perfusion.  Circulation. 2004;  109 3096-3105
• 18 Wu E, Ortiz J T, Tejedor P. et al . Infarct size by contrast enhanced cardiac magnetic resonance is a stronger predictor of outcomes than left ventricular ejection fraction or end-systolic volume index: prospective cohort study.  Heart. 2008;  94 730-736
• 19 Rehwald W G, Fieno D S, Chen E L. et al . Myocardial magnetic resonance imaging contrast agent concentrations after reversible and irreversible ischemic injury.  Circulation. 2002;  105 224-229
• 20 Hunold P, Kreitner K F, Barkhausen J. „Tot oder lebendig?”: Wie und warum myokardiale Vitalitätsdiagnostik mit MRT funktioniert.  Fortschr Röntgenstr. 2007;  179 1016-1024
• 21 Manciet L H, Poole D C, McDonagh P F. et al . Microvascular compression during myocardial ischemia: mechanistic basis for no-reflow phenomenon.  Am J Physiol. 1994;  266 H1541-H1550
• 22 Topol E J, Yadav J S. Recognition of the importance of embolization in atherosclerotic vascular disease.  Circulation. 2000;  101 570-580
• 23 Piana R N, Paik G Y, Moscucci M. et al . Incidence and treatment of ‘no-reflow’ after percutaneous coronary intervention.  Circulation. 1994;  89 2514-2518
• 24 Sievers B, Elliott M D, Hurwitz L M. et al . Rapid detection of myocardial infarction by subsecond, free-breathing delayed contrast-enhancement cardiovascular magnetic resonance.  Circulation. 2007;  115 236-244
• 25 Choi S I, Jiang C Z, Lim K H. et al . Application of breath-hold T 2-weighted, first-pass perfusion and gadolinium-enhanced T 1-weighted MR imaging for assessment of myocardial viability in a pig model.  J Magn Reson Imaging. 2000;  11 476-480
• 26 Saeed M, Lund G, Wendland M F. et al . Magnetic resonance characterization of the peri-infarction zone of reperfused myocardial infarction with necrosis-specific and extracellular nonspecific contrast media.  Circulation. 2001;  103 871-876
• 27 Oshinski J N, Yang Z, Jones J R. et al . Imaging time after Gd-DTPA injection is critical in using delayed enhancement to determine infarct size accurately with magnetic resonance imaging.  Circulation. 2001;  104 2838-2842
• 28 Wagner A, Mahrholdt H, Thomson L. et al . Effects of time, dose, and inversion time for acute myocardial infarct size measurements based on magnetic resonance imaging-delayed contrast enhancement.  J Am Coll Cardiol. 2006;  47 2027-2033
• 29 Kim R J, Fieno D S, Parrish T B. et al . Relationship of MRI delayed contrast enhancement to irreversible injury, infarct age, and contractile function.  Circulation. 1999;  100 1992-2002
• 30 Saeed M, Bremerich J, Wendland M F. et al . Reperfused myocardial infarction as seen with use of necrosis-specific versus standard extracellular MR contrast media in rats.  Radiology. 1999;  213 247-257
• 31 Judd R M, Lugo-Olivieri C H, Arai M. et al . Physiological basis of myocardial contrast enhancement in fast magnetic resonance images of 2-day-old reperfused canine infarcts.  Circulation. 1995;  92 1902-1910
• 32 Rochitte C E, Lima J A, Bluemke D A. et al . Magnitude and time course of microvascular obstruction and tissue injury after acute myocardial infarction.  Circulation. 1998;  98 1006-1014