Impact of residual thrombus burden on ventricular deformation after acute myocardial infarction: A sub-analysis from an intravascular optical coherence tomography study.

BACKGROUND

Coronary residual thrombus before stenting in ST-segment elevation myocardial infarction (STEMI) has been linked to microvascular injury but its impact on ventricular deformation and cardiac dysfunction in longer term remains unclear.

METHODS

This was a post-hoc sub-analysis from an optical coherence tomography registry. Residual thrombus before stenting was measured geometrically and maximal thrombus-to-lumen area ratio (MTR) was reported. Cardiovascular magnetic resonance (CMR) follow-ups were performed at 30 days post STEMI. The primary outcomes were CMR-derived parameters including left ventricular ejection fraction (LVEF), infarct size, microvascular obstruction (MVO), and left ventricular global strains in radial (GRS), circumferential (GCS), longitudinal (GLS) directions.

FINDINGS

From March 2017 to March 2019, forty-two patients with first-ever anterior STEMI were included. Average CMR follow-up time was 33 (IQR 30-37) days. In multivariable analysis, MTR was significantly associated with LVEF (per 10%, adjusted  = -1·96, 95%CI -3·66 to -0·26), MVO (per 10%, adjusted  = 0·07, 95%CI 0·01 to 0·13), GRS (per 10%, adjusted  = -1·26, 95%CI -2·28 to -0·23), and GCS (per 10%, adjusted  = 0·53, 95%CI 0·01 to 1·06). However, it was not related to GLS (per 10%, adjusted  = 0·29, 95%CI -0·85 to 1·43) or infarct size (per 10%, adjusted  = 0·07, 95%CI -0·40 to 0·55).

INTERPRETATION

Larger residual thrombus burden was associated with worse GRS and GCS but not GLS after a first anterior myocardial infarction.

FUNDING

This work was supported by Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences (2016-I2M-1-009), National Natural Science Foundation of China (81,970,308, 81,930,044, and 81,620,108,015), Sanming Project of Medicine in Shenzhen (SZSM201911017), and Shenzhen Key Medical Discipline Construction Fund (No. SZXK001).