Cardiac magnetic resonance characteristics of ST-segment elevation myocardial infarction in the acute period and during long-term follow up – prognostic role of microvascular obstruction
█ Original article
Czimbalmos Csilla, Csécs Ibolya, Tóth Attila, Suhai Ferenc Imre, Dohy Zsófia, Szabó Liliána Erzsébet, Bárczi György, Zima Endre, Becker Dávid, Merkely Béla*, Vágó Hajnalka*
Semmelweis Egyetem, Városmajori Szív- és Érgyógyászati Klinika, Budapest
*Megosztott utolsó szerzők
Cardiac magnetic resonance imaging (CMR) provides tissue-specific information by assessment of myocardial necrosis/scar and microvascular obstruction (MVO), moreover it is the gold standard method of evaluation of left and right ventricular volumes, ejection fractions and mass. The aim of the study was to evaluate the CMR characteristics of ST-elevation myocardial infarction in the acute phase and during follow-up, and the correlation between CMR parameters and adverse cardiac events during the follow-up period.
104 patients (69 male, 35 female; 60±12 years) were examined with CMR after percutaneous coronary intervention because of STEMI within 12 hours in the acute phase (2-4th day) and after 4–6 months (n=82). During the follow-up adverse event was regarded as mortality caused by any reason and hospitalisation because of cardiac causes. In long and short-axis planes ECG synchronized cine movie, T2-weighted spectral inversion recovery (SPIR), and delayed contrast enhancement (DE) images were taken. Left and right ventricular volumes, ejection fractions (EF), mass, myocardial necrosis, MVO and scar tissue were evaluated.
We demonstrated a strong, positive correlation between acute scar extent and level of CK-MB (r=0.52), and negative correlation between acute scar extension and acute left ventricular ejection fraction (LVEF)(r= –0,40). The left ventricular parameters at follow-up CMR changed significantly (p<0,001): LVEF (47.3±9.7% vs. 51.2±11.6%), left ventricular end diastolic volume index (LVEDVi) (88.33±20.9 ml/m2 vs. 96.4±23 ml/m2) and stroke volume index (SVi) (41.3±7.1 ml/m2 vs. 47.3±7.7 ml/m2) increased. Left ventricular mass index (LVMi) (73.7±16.9 g vs. 66.2±14.3 g) decreased and the scar tissue shrank (26.2±17.1 g vs. 18.4±13.1 g). MVO was detected in acute phase in 35.6% of the patients. During the 602±204-day follow-up adverse event was detected in 27 patients. We demonstrated positive correlation between the extension of MVO detected in the acute phase and adverse event (p<0.05).
CMR is an outstanding noninvasive method, which helps us in the evaluation of myocardial viability and ventricular remodeling after acute myocardial infarction, moreover in the detection and quantification of MVO, which prognostic role was proved in this study.