Impact of Microvascular Obstruction on Left Atrial and Ventricular Myocardial Deformation and In-hospital...

The purpose of this study was to explore the impact of microvascular obstruction (MVO) on left atrial and ventricular parameters, as well as in-hospital complications, in patients with reperfused ST-segment elevation myocardial infarction (STEMI) who underwent cardiovascular magnetic resonance (CMR) within 7 days.

This retrospective study included CMR scans of 95 consecutive patients with reperfused STEMI (79 males, mean age: 64.2 ± 10.3 y). Among them, 30 showed MVO presence (28 males, 93%; mean age: 64.1 ± 10.5 y), defined as a hypo-enhanced core surrounded by hyper-enhanced myocardium in late gadolinium enhancement (LGE) sequences.

Patients with MVO demonstrated a higher prevalence of hypertension ( P = 0.012) and a lower LV ejection fraction (30.5 ± 9.1% vs 37.8 ± 13.8%, P = 0.011) compared with patients without MVO. In addition, patients with MVO showed impaired reservoir, conduit, booster function, global longitudinal strain (GLS), global circumferential strain (GCS), global radial strain (GRS), higher LGE extent, and in-hospital complications compared with STEMI patients without MVO ( P = 0.001 for all).In multivariable analysis, reservoir, conduit, booster function, GLS, GCS, and GRS were associated with MVO presence, independently of LV ejection fraction and LGE extent ( P = 0.001 for all).

In reperfused STEMI patients, left atrial and ventricular strain parameters are altered by the presence of MVO, in addition to impaired LV ejection fraction and LGE extent.