Detektion und Charakterisierung linksventrikulärer Thromben mittels MRT im Vergleich zur transthorakalen Echokardiographie

Zusammenfassung

Fragestellung: Evaluiert werden sollte die Bedeutung der kardialen MRT in der Diagnostik linksventrikulärer Thromben bei chronischem Myokardinfarkt im Vergleich zur transthorakalen Echokardiographie. Material und Methode: 82 Patienten (55 Männer und 27 Frauen, Alter 36 bis 79, Mittelwert 59 ± 11 Jahre) mit chronischem, mehr als 6 Monate alten Myokardinfarkt wurden mittels transthorakaler Echokardiographie und kontrastverstärkter kardialer MRT untersucht. Ergebnisse: Die transthorakale Echokardiographie konnte 12, die kontrastverstärkte kardiale MRT 35 linksventrikuläre Thromben im Bereich der Infarktnarbe identifizieren. Abgesehen von 2 kleinen apikalen Thromben handelte es sich bei den ausschließlich im MRT detektierten Thromben um parietale Thromben. Linksventrikuläre Thromben fanden sich insgesamt gehäuft bei Patienten mit mittel- bis höhergradig eingeschränkter systolischer linksventrikulärer Gesamtfunktion (32/42 [76 %]) und bei Aneurysmabildung des linken Ventrikels (21/24 [84 %]). Schlussfolgerung: Die kardiale MRT ist der Echokardiographie vor allem in der Darstellung parietaler Thromben nach abgelaufenem Myokardinfarkt überlegen. Intrakavitäre Thromben werden gehäuft bei Patienten mit höhergradig reduzierter LV-Funktion oder schweren regionalen Kontraktionsstörungen in Form einer postinfarziellen linksventrikulären Aneurysmabildung gefunden.

Abstract

Purpose: Transthoracic echocardiography is the routine diagnostic procedure in assessing patients with left ventricular thrombi, but is limited by the acoustic window and poor contrast between thrombus and adjacent myocardium. This study evaluates the role of cardiac MRI in the detection of left ventricular thrombi in patients with chronic myocardial infarction compared to standard transthoracic echocardiography. Materials and Methods: In 82 patients (55 men and 27 women, age 36 to 79 years, median 59 ± 11 years) who suffered a myocardial infarction more than 6 months earlier, transthoracic echocardiography and MRI were performed. The MRI protocol included steady state cine imaging (true FISP: TR 3.0 ms, TE 1.5 ms, FA 65°) in standard long and short axis orientation and contrast-enhanced imaging using a 3D IR-FLASH sequence with long inversion time (TR 4 ms, TE 1.43 ms, FA 10°, TI 300 ms) early, and a 2D IR-FLASH sequence with optimized inversion time (TR 8 ms, TE 4.3 ms, FA 20°, TI 180 - 280 ms) late after administration of gadolinium. Results: Transthoracic echocardiography depicted 12 thrombi. Contrast-enhanced MRI confirmed these 12 thrombi and detected 23 additional thrombi. With the exception of 2 very small apical thrombi only visible on contrast-enhanced MR images, spherical thrombi were diagnosed by both techniques, whereas only contrast-enhanced MRI was able to visualize mural thrombi. Left ventricular thrombi were more frequently diagnosed in patients with moderate to severe impairment of the left ventricular systolic function, 32/42 (76 %), or in patients with left ventricular aneurysms, 21/24 (84 %). Conclusion: Contrast-enhanced MRI is mostly superior to transthoracic echocardiography in diagnosing mural left ventricular thrombi in patients who had suffered a myocardial infarction. Intracavitary thrombi are more frequently found in patients with impaired regional and global left ventricular function.

Key words

Myocardial infarction - left ventricular aneurysm - left ventricular thrombus - transthoracic echocardiography - contrast-enhanced MRI

Literatur

• 1 Hamm C W AH, Bode C, Giannitsis E. et al . Leitlinien: Akutes Koronarsyndrom.  Deutsche Gesellschaft für Kardiologie. 2004; 
• 2 Lange R A, Hillis L D. Immediate angioplasty for acute myocardial infarction.  N Engl J Med. 1993;  328 726-728
• 3 international randomized trial comparing four thrombolytic strategies for acute myocardial infarction . The GUSTO investigators.  N Engl J Med. 1993;  329 673-682
• 4 Forman M B, Collins H W, Kopelman H A. et al . Determinants of left ventricular aneurysm formation after anterior myocardial infarction: a clinical and angiographic study.  J Am Coll Cardiol. 1986;  8 1256-1262
• 5 Abrams D L, Edelist A, Luria M H. et al . Ventricular Aneurysm. A Reappraisal Based on a Study of Sixty-Five Consecutive Autopsied Cases.  Circulation. 1963;  27 164-169
• 6 Chiarella F, Santoro E, Domenicucci S. et al . Predischarge two-dimensional echocardiographic evaluation of left ventricular thrombosis after acute myocardial infarction in the GISSI-3 study.  Am J Cardiol. 1998;  81 822-827
• 7 Asinger R W, Mikell F L, Elsperger J. et al . Incidence of left-ventricular thrombosis after acute transmural myocardial infarction. Serial evaluation by two-dimensional echocardiography.  N Engl J Med. 1981;  305 297-302
• 8 Jugdutt B I, Sivaram C A. Prospective two-dimensional echocardiographic evaluation of left ventricular thrombus and embolism after acute myocardial infarction.  J Am Coll Cardiol. 1989;  13 554-564
• 9 Vecchio C, Chiarella F, Lupi G. et al . Left ventricular thrombus in anterior acute myocardial infarction after thrombolysis. A GISSI-2 connected study.  Circulation. 1991;  84 512-519
• 10 Mooe T, Teien D, Karp K. et al . Long term follow up of patients with anterior myocardial infarction complicated by left ventricular thrombus in the thrombolytic era.  Heart. 1996;  75 252-256
• 11 van Dantzig J M, Delemarre B J, Bot H. et al . Left ventricular thrombus in acute myocardial infarction.  Eur Heart J. 1996;  17 1640-1645
• 12 Hirai T, Fujita M, Nakajima H. et al . Importance of collateral circulation for prevention of left ventricular aneurysm formation in acute myocardial infarction.  Circulation. 1989;  79 791-796
• 13 Vaitkus P T, Barnathan E S. Embolic potential, prevention and management of mural thrombus complicating anterior myocardial infarction: a meta-analysis.  J Am Coll Cardiol. 1993;  22 1004-1009
• 14 Visser C A, Kan G, Meltzer R S. et al . Long-term follow-up of left ventricular thrombus after acute myocardial infarction. A two-dimensional echocardiographic study in 96 patients.  Chest. 1984;  86 532-536
• 15 Stratton J R, Lighty G W Jr, Pearlman A S. et al . Detection of left ventricular thrombus by two-dimensional echocardiography: sensitivity, specificity, and causes of uncertainty.  Circulation. 1982;  66 156-166
• 16 Simonetti O P, Kim R J, Fieno D S. et al . An improved MR imaging technique for the visualization of myocardial infarction.  Radiology. 2001;  218 215-223
• 17 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
• 18 Barkhausen J, Hunold P, Eggebrecht H. et al . Detection and characterization of intracardiac thrombi on MR imaging.  AJR Am J Roentgenol. 2002;  179 1539-1544
• 19 Mollet N R, Dymarkowski S, Volders W. et al . Visualization of ventricular thrombi with contrast-enhanced magnetic resonance imaging in patients with ischemic heart disease.  Circulation. 2002;  106 2873-2876
• 20 Cheitlin M D, Armstrong W F, Aurigemma G P. et al . ACC/AHA/ASE 2003 guideline update for the clinical application of echocardiography: summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/ASE Committee to Update the 1997 Guidelines for the Clinical Application of Echocardiography).  Circulation. 2003;  108 1146-1162
• 21 Cheitlin M D, Alpert J S, Armstrong W F. et al . ACC/AHA Guidelines for the Clinical Application of Echocardiography. A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Clinical Application of Echocardiography). Developed in colloboration with the American Society of Echocardiography.  Circulation. 1997;  95 1686-1744
• 22 Barkhausen J H, Eggebrecht P, Sabin H. et al . Comparison of gradient-echo and steady state free precession sequences for 3D-navigator MR angiography of coronary arteries.  Fortschr Röntgenstr. 2002;  174 725-730
• 23 Hunold P, Brandt-Mainz K, Freudenberg L. et al . Myokardiale Vitalitätsdiagnostik mit kontrastverstärkter Magnetresonanztomographie - Vergleich des „late enhancement”-Konzepts mit der Positronen-Emissions-Tomographie.  Fortschr Röntgenstr. 2002;  174 867-873
• 24 Paydarfar D, Krieger D, Dib N. et al . In vivo magnetic resonance imaging and surgical histopathology of intracardiac masses: distinct features of subacute thrombi.  Cardiology. 2001;  95 40-47
• 25 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
• 26 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