Influence of microvascular dysfunction on regional myocardial deformation post-acute myocardial infarction: insights from a novel angiographic index for assessing myocardial tissue-level reperfusion

Abstract

To investigate the impact of microvascular dysfunction assessed by angiography on myocardial deformation assessed by two-dimensional speckle-tracking echocardiography in ST-segment elevation myocardial infarction (STEMI). A total of 121 STEMI patients who received primary percutaneous coronary intervention were included. Thrombolysis in myocardial infarction, Myocardial Perfusion Frame Count (TMPFC), a novel angiographic method to assess myocardial perfusion, was used to evaluate microvascular dysfunction. Two-dimensional speckle-tracking echocardiography was performed at 3-7 days after reperfusion. The infarction related regional longitudinal (RLS) strains as well as circumferential (RCS) and radial (RRS) ones, along with global longitudinal, circumferential (GCS), and radial (GRS) strains were measured. Patients with microvascular dysfunction had decreased peak amplitude of RLS (p = 0.012), RCS (p < 0.001), RRS (p = 0.012) at the regional level and decreased peak amplitude of GCS (p = 0.005), GRS (p = 0.012) at the global level. The RCS to RLS and RCS to RRS ratios were significantly different between patients without than with microvascular dysfunction (1.28 ± 0.31 vs. 1.07 ± 0.47, p = 0.027 and 0.69 ± 0.33 vs. 0.56 ± 0.28, p = 0.047). Receiver operator characteristics curves identified a cutoff value of 94 frames for TMPFC to differentiate between normal and abnormal wall motion score index in the sub-acute phase of STEMI (AUC = 0.72; p < 0.001). In the sub-acute phase of STEMI, the presence of microvascular dysfunction in infarcted tissue relates to reduced global and regional myocardial deformation. RCS alterations were more significant than RLS and RRS between patients with than without microvascular dysfunction. TMPFC was useful to predict left ventricular systolic dysfunction in the sub-acute phase of STEMI.

Prognostic nutritional index predicts clinical outcome in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

“…Despite recent advances in techniques and improved outcomes of percutaneous coronary intervention (PCI), patients with acute ST-segment elevation myocardial infarction (STEMI) are still at an increased risk of mortality even after timely revascularization 1–4 . Therefore, early risk stratification at the time of presentation is of clinical importance.…”

Chinese Expert Consensus on Microvascular Protection Strategy During Emergency Percutaneous Coronary Intervention Therapy in Patients With ST-elevation Myocardial Infarction

“…[24] The recovery of cardiac function in STEMI patients with a TMPFC <95.5 frames is more obvious. [25]…”

Cardiovascular imaging 2016 in the International Journal of Cardiovascular Imaging

“…Author He et al described the use of the Myocardial Perfusion Frame Count (TMPFC) technique as an indicator to predict left ventricular systolic dysfunction in the sub-acute phase of STEMI [1]. They counted the number of frames from the first appearance of myocardial blush beyond the infarct related artery until the frame when contrast or myocardial blush disappeared; frame rate was either 15 or 30 f/sec.…”