Preoperative QRS Duration Predicts the Responsiveness of Chronic Heart Failure Patients with Pacemaker Indications to Left Bundle Branch Area Pacing Treatment.

BACKGROUND: This study investigated the predictive value of preoperative QRS duration (QRSd) in responsiveness of chronic heart failure (CHF) patients with pacemaker indications to the left bundle branch area pacing (LBBAP). METHODS: Thirty-one CHF patients with cardiac function categorized as NYHA class II or above and indications for pacemaker therapy who successfully underwent LBBAP treatment were enrolled in this study. Based on the 12-month postoperative responsiveness to treatment, patients were divided into a responsiveness group (N = 16) and a no-responsiveness group (N = 15). Data from all patients were collected for analysis. Multivariate binary logistic regression analysis was used to determine the independent factors associated with the responsiveness to LBBAP treatment. RESULTS: Among the 31 patients with LBBAP, 16 patients (51.6%) responded to the treatment, and 15 patients (48.4%) had no response. There were significant differences between the two groups with regard to complete left bundle branch block (CLBBB), preoperative QRSd, and preoperative left ventricular peak time (LVAT). Univariate logistic regression analysis showed that CLBBB, preoperative QRSd, and preoperative LVAT all were significantly correlated with responsiveness to LBBAP. Multivariate binary logistic regression analysis showed that QRSd was an independent predictor of responsiveness to LBBAP. The maximum area under the ROC curve for QRSd was 0.827 (95%C.I.:0.663-0.991), the maximum Youden index was 0.679, with the optimal cutoff point of QRSd ≥ 153 ms, a sensitivity of 81.3%, and a specificity of 86.7%. CONCLUSION: Preoperative QRSd predicts the responsiveness of CHF patients with pacemaker indications to LBBAP.

Knockdown of circROBO2 attenuates acute myocardial infarction through regulating the miR-1184/TRADD axis.

BACKGROUND: Studies have found that circular RNAs (circRNAs) play key roles in cardiovascular diseases. However, the function of circROBO2 in acute myocardial infarction (AMI) is unclear. This study aimed to investigate the pathogenesis of circROBO2 in AMI. METHODS: qRT-PCR and Western blot were used to determine the expression levels of circROBO2, miR-1184, and TRADD in AMI and sham-operated mouse models at mRNA and protein level, respectively. The relationship among miR-1184, circROBO2 and TRADD was evaluated by RNA immunoprecipitation (RIP) analysis and luciferase reporter gene analysis. The roles of circROBO2, miR-1184, and TRADD in myocardial cell apoptosis were evaluated using flow cytometry. Ultrasound echocardiography, serum creatine kinase MB (CK-MB) and lactate dehydrogenase (LDH), myocardial infarction area, and myocardial cell apoptosis were measured to examine the effects of circROBO2 on myocardial injury. RESULTS: The expression levels of miR-1184 were significantly reduced, and the expression levels of circROBO2 and TRADD were significantly increased in MI group. CircROBO2 acted as a sponge for miR-1184 by upregulating the expression of TRADD. In addition, overexpression of miR-1184 enhanced the protective effect of knockdown of circROBO2 by partially inhibiting the expression of TRADD in vivo and in vitro. CONCLUSION: Knockdown of circROBO2 reduced the apoptosis of cardiomyocytes by increasing the expression levels of miR-1184, which in turn decreased the expression levels of TRADD in the myocardium post-MI.