Association of platelet-SDF-1 with hemodynamic function and infarct size using cardiac MR in patients with AMI

Purpose: Platelet-derived stromal-cell-derived factor-1 (SDF-1) plays an important role in trafficking hematopoetic progenitor cells for tissue regeneration and neovascularisation. The aim was to evaluate platelet-SDF-1 and CD34(+) progenitor cells in patients with acute myocardial infarction (AMI) compared with hemodynamic function and infarct size using late gadolinium enhancement (LGE) cardiac magnetic resonance (CMR) imaging.

Materials and methods: We consecutively evaluated 40 patients with AMI, who received coronary angiography for primary coronary intervention. Blood was sampled for flow cytometry to determine mean fluorescence intensity (MFI) of platelet-SDF-1 and for isolation of CD34(+) progenitor cells. 48h and three months after coronary stenting, all patients underwent 1.5T CMR for volumetric assessment and LGE.

Results: Patients with enhanced platelet-SDF-1 expression (median≥68.5MFI) showed a significant amelioration of left ventricular ejection fraction (LVEF) (baseline vs. follow-up mean±SD: 45±6% vs. 56±6%; P=0.018) and of stroke volume (73.1±19.1mL vs. 89.9±21.3mL; P=0.032) at three-month follow-up in contrast to patients with a decreased platelet-SDF-1 expression level (LVEF: 53±8% vs. 56±10%; P=0.267; stroke volume: 85.6±23.1mL vs. 87.4±23.2mL; P=0.803). Inversely, LGE infarct size showed significantly reduced in patients with enhanced platelet-SDF-1 expression at three months (18.9±12mL vs. 6.3±5.1mL; P=0.002) compared to patients with decreased platelet-SDF-1 (12.7±12.7mL vs. 7.6±8.4mL; P=0.156). Time-dependent autocorrelation coefficients shifted for both SV (lag 1: r=-0.368; P=0.001) and the number of CD34(+) cells (lag 1: r=0.633; P=0.001) to a positive autocorrelation (SV; lag 2: r=0.295; P=0.001; CD34(+) cells; lag 2: r=0.287; P=0.001). Patients with increased number of CD34(+) cells (median≥420cells/hpf) showed a significant amelioration of stroke volume in three-month follow-up (83.9±5.3mL vs. 99.4±4.1mL; P=0.020) compared with patients with decreased number of CD34(+) cells (69.3±4.1mL vs. 76.1±3.2mL; P=0.282).

Conclusions: Platelet-SDF-1 and number of CD34(+) progenitor cells are associated with CMR hemodynamic function in patients with AMI.