Prognostic implications of left ventricular torsion measured by feature-tracking cardiac magnetic resonance in patients with ST-elevation myocardial infarction.

AIMS: The prognostic implication of left ventricular (LV) torsion on ST-elevation myocardial infarction (STEMI) is unclear. METHODS AND RESULTS: We analysed cardiovascular magnetic resonance (CMR) findings of 420 patients from a registry study (NCT03768453). These patients received CMR examination within 1 week after timely primary percutaneous coronary intervention. LV torsion and other CMR indexes were measured. Compared with healthy control subjects, STEMI significantly decreased patients' LV torsion (1.04 vs. 1.63°/cm, P < 0.001). During follow-up (median, 52 months), the reduction of LV torsion was greater in patients with than without composite major adverse cardiac and cerebrovascular events (MACCEs, 0.79 vs. 1.08°/cm, P < 0.001). The risk of MACCEs would increase to 1.125- or 1.092-fold, and the risk of 1-year LV remodelling would increase to 1.110- or 1.082-fold for every 0.1°/cm reduction in LV torsion after adjustment for clinical or CMR parameters respectively. When divided dichotomously, patients with LV torsion≤ 0.802°/cm had significantly higher risk of MACCEs (40.2 vs. 12.3%, P < 0.001) and more remarkable LV remodelling (46.1 vs. 11.9%, P < 0.001) than patients with better LV torsion. The addition of LV torsion to conventional prognostic factors such as the LV ejection fraction and infarction size led to a better risk classification model of patients for both MACCEs and LV remodelling. Finally, tobacco use, worse post-PCI flow, and greater microvascular obstruction size were presumptive risk factors for reduced LV torsion. CONCLUSION: LV torsion measured by CMR is closely associated with the prognosis of STEMI and would be a promising indicator to improve patients' risk stratification. CLINICAL TRIAL REGISTRATION: Clinicaltrials.gov, NCT03768453.

Impact of Concomitant Impairments of the Left and Right Ventricular Myocardial Strain on the Prognoses of Patients With ST-Elevation Myocardial Infarction.

Background: The impact of concomitant impairments of left and right ventricular (LV and RV) strain on the long-term prognosis of acute ST-elevation myocardial infarction (STEMI) is not clear. Methods: We analyzed CMR images and followed up 420 first STEMI patients from the EARLY Assessment of MYOcardial Tissue Characteristics by CMR in STEMI (EARLY-MYO-CMR) registry (NCT03768453). These patients received timely primary percutaneous coronary intervention (PCI) within 12 h and CMR examination within 1 week (median, 5 days; range, 2-7 days) after infarction. Global longitudinal strain (GLS), global radial strain (GRS), and global circumferential strain (GCS) of both ventricles were measured based on CMR cine images. Conventional CMR indexes were also assessed. Primary clinical outcome was composite major adverse cardiac and cerebrovascular events (MACCEs) including cardiovascular death, re-infarction, re-hospitalization for heart failure and stroke. In addition, CMR data from 40 people without apparent heart disease were used as control group. Results: Compared to controls, both LV and RV strains were remarkably reduced in STEMI patients. During follow-up (median: 52 months, interquartile range: 29-68 months), 80 patients experienced major adverse cardiac and cerebrovascular events (MACCEs) including cardiovascular death, re-infarction, heart failure, and stroke. LV-GCS > -11.20% was an independent predictor of MACCEs (P < 0.001). RV-GRS was the only RV strain index that could effectively predict the risk of MACCEs (AUC = 0.604, 95% CI [0.533, 0.674], P = 0.004). Patient with RV-GRS ≤ 38.79% experienced more MACCEs than those with preserved RV-GRS (log rank P < 0.001). Moreover, patients with the concomitant decrease of LV-GCS and RV-GRS were more likely to experience MACCEs than patients with decreased LV-GCS alone (log rank P = 0.010). RV-GRS was incremental to LV-GCS for the predictive power of MACCEs (continuous NRI: 0.327; 95% CI: 0.095-0.558; P = 0.006). Finally, tobacco use (P = 0.003), right coronary artery involvement (P = 0.002), and LV-GCS > -11.20% (P = 0.012) was correlated with lower RV-GRS. Conclusions: The concomitant decrease of LV and RV strain is associated with a worse long-term prognosis than impaired LV strain alone. Combination assessment of both LV and RV strain indexes could improve risk stratification of patients with STEMI. Trial Registration: ClinicalTrials.gov, NCT03768453. Registered 7 December 2018 - Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03768453.

Effect of acupoint injection with bone marrow mesenchymal stem cells on the blood flow in rats with hind limb ischemia / 中国针灸

<p><b>OBJECTIVE</b>To investigate the best injection method of the bone marrow mesenchymal stem cells (BM-MSCs) transplantation for the treatment of a rat model with hind limb ischemia.</p><p><b>METHODS</b>Twenty four SD rats with hind limb ischemia were randomly divided into four groups: control group, model group, acupoint BM-MSCs injection group (API group) and thigh muscle BM-MSCs injection group (TMI group). The acupoints of "Sanyinjiao" (SP 6), "Housanli" (ST 36), "Zhaohai" (KI 6), "Huantiao" (GB 30) and "Yanglingquan" (GB 34) were selected for API group, and five non-acupoints were selected on gastrocnemius and adductor of ischemic hind limb for TMI group. Both groups were accepted BM-MSCs transplantion. Model rat with hind limb ischemia was established with the method of blocking the femoral artery and its branches. The changes of blood flow (perfuse unit, PU) was monitored with laser Doppler flowmetry (LDF). In order to describe the visual changes in blood flow, the PU index (PUI) was determined as the ratio of ischemic to non-ischemic hind limb blood perfusion. And also, the levels of VEGF,bFGF in serum were tested to analyze the immunohistochemical expression quantity of VEGF and bFGF.</p><p><b>RESULTS</b>Comparing with the model and the TMI groups, the PUI value on 3rd, 14th and 21th days after BM-MSCs transplantation were significantly increased in the API group (P < 0.05, P < 0.01). In contrast to the model group, the VEGF,bFGF levels in serum and the immunohistochemical expression quantity of VEGF and bFGF in the API and TMI groups were significantly increased (all P < 0.01).</p><p><b>CONCLUSION</b>Transplantation of BM-MSCs through the acupoint can more significantly and quickly increase the blood flow and cause the greater improvement on hind limb ischemia than that of through the way of muscle injection.</p>