Myocardial strain characteristics in ST-segment elevation myocardial infarction patients with left ventricular thrombus: a cardiac magnetic resonance imaging study

Abstract

Background: Left ventricular thrombus (LVT) is a serious complication of ST-segment elevation myocardial infarction (STEMI). This study investigated the magnetic resonance (MR) myocardial strain characteristics of LVT in patients without left ventricular aneurysm.

Methods: A total of 199 patients diagnosed with STEMI underwent cardiac MR (CMR) examination. According to the presence or absence of LVT, the patients were divided into two groups. There were 41 cases with LVT and 158 cases without LVT. Clinical data and CMR information were compared between the two groups, including left ventricular ejection fraction (LVEF), left ventricular volume, myocardial thickening rate, and other cardiac function parameters, as well as circumferential strain (CS), radial strain (RS), longitudinal strain (LS), and other myocardial strain parameters.

Results: Patients with LVT had significantly higher B-type natriuretic peptide (BNP) levels compared to the non-thrombus group (1,533.37±1,274.08 pg/mL, 770.53±757.06 pg/mL, P<0.05). The average LVEF in the LVT group was significantly lower (28.51%±16.21%), and the left ventricular end-diastolic (261.23±126.68 mL) and end-systolic volumes (196.16±122.63 mL) were both significantly increased (P<0.05). The overall global CS (-10.84%±5.05%), global RS (19.31%±12.05%), and global LS (-4.28%±4.62%) of the left ventricle in the LVT group were significantly lower than those without LVT, and except for the basal segment RS (20.22%±10.13%), the CS, RS, and LS of the other myocardial segments were all significantly reduced (P<0.05).

Conclusions: There is still a high incidence of LVT in STEMI patients without left ventricular aneurysm. Myocardial strain on CMR imaging provides more information for the diagnosis of LVT.

Keywords: Left ventricular thrombus (LVT); ST-segment elevation myocardial infarction (STEMI); cardiac magnetic resonance imaging (CMR imaging); myocardial strain; strain analysis.

Figure 1

Study flow chart. CABG, coronary artery bypass grafting surgery; CMR, cardiac magnetic resonance; LVT, left ventricular thrombus; PCI, percutaneous coronary intervention; STEMI, ST-segment elevation myocardial infarction.

Figure 2

Comparison of longitudinal, circumferential, and radial strain of each segment between the two groups. Green indicates that the strain at this segment is statistically different from that in the non-thrombus group (P<0.05).