The acute and long-term outcome of patients with ST segment elevation myocardial infarction concurrent with chronic total occlusion / 中华心血管病杂志

Objective: To evaluate the acute and long-term outcome of patients with ST segment elevation myocardial infarction (STEMI) concurrent with chronic total occlusion (CTO) undergoing primary percutaneous coronary intervention (PCI). Methods: 11 905 STEMI patients from the China Acute Myocardial Infarction Registry were enrolled in this study and divided into CTO group and non-CTO group according to the angiography results of primary PCI. 1∶3 propensity score matching was used to match the patients between the two groups. The primary endpoint was in-hospital mortality and mortality at 1-year post PCI. The secondary endpoint was major adverse cardiovascular events (MACE) including death, re-myocardial infarction, revascularization, heart failure associated readmission, stroke and major bleeding at 1-year post PCI. Results: There were 931 CTO patients (7.8%) in this cohort (male=755 (81.1%), mean age (62.2±11.4 years)). The rest 10 974 patients were STEMI without CTO (male=8 829 (80.5%),mean age (60.0±11.8) years). After propensity score matching, 896 patients were enrolled in CTO group and 2 688 in non-CTO group. In-hospital mortality was significantly higher in the CTO group than in non-CTO group (4.2% vs. 2.4%, P=0.006). The ratio of all cause death, cardiac death, and MACE at 1-year follow up was also significantly higher in the CTO group than in non-CTO group (8.5% vs. 4.4%, P<0.001, 5.3% vs. 2.6%, P=0.001, 35.1% vs. 23.3%, P<0.001, respectively). Multiple regression analysis showed that CTO (HR=1.54, 95%CI 1.06-2.22, P=0.022), advanced age (HR=1.06, 95%CI 1.04-1.08, P<0.001), and previous heart failure history (HR=4.10, 95%CI 1.90-8.83, P<0.001) were independent risk factors of 1-year mortality. Conclusions: The in-hospital and 1-year mortality increased significantly in STEMI patients concurrent with CTO. CTO, advanced age and history of heart failure are independent risk factors of 1-year death among STEMI patients.

Evaluation of very early neointimal coverage post drug-eluting stent implantation using optical coherence tomography / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the neointimal coverage at the very early phase after drug-eluting stent (DES) implantation using optical coherence tomography (OCT).</p><p><b>METHODS</b>OCT examination was performed immediately after stent deployment and about one week post stenting in 12 patients with coronary artery disease to detect neointimal coverage and stent thrombus. Sirolimus eluting stent implantation was also performed in 5 healthy Chinese minipigs, OCT and histopathology examination were made one week later in these minipigs.</p><p><b>RESULTS</b>(1) Twenty-nine DES were implanted in 12 patients. There was no major cardiovascular event post stenting. The mean time of follow-up was (7.7 ± 2.6) d, the mean percentage of stent coverage was (21.8 ± 17.7)%, and neointimal hyperplasia thickness was (42.9 ± 32.2) µm and the percentage of malapposition struts was (1.5 ± 3.0)%, respectively. Mural stent thrombus was found in 2 of the 12 patients (the percentage is 16.7%). (2) In the minipigs model, OCT evidenced that (43.2 ± 11.5)% struts were covered by neointima with a mean neointimal hyperplasia thickness of (24.0 ± 8.5) µm at one week. Histopathology examination illustrated that the neointima was mainly consisted of proteoglycan, inflammation cells, fibrin and organized thrombus at the very early phase after DES implantation, while endothelial cells were barely found on the neointima.</p><p><b>CONCLUSIONS</b>Neointimal coverage is found as early as one week after DES implantation by OCT. The covered struts rate is very low and the main components of neointima are proteoglycan, inflammation cells, fibrin and organized thrombus. Re-endothelialization is rather poor at the very early phase post DES implantation.</p>

Ischemic preconditioning attenuates myocardial no-reflow and reperfusion injury after revascularization of acute myocardial infarction by reducing myocardial edema via the protein kinase A pathway / 中华心血管病杂志

<p><b>OBJECTIVE</b>Myocardial edema plays an important role in the development of myocardial no-reflow and reperfusion injury after the revascularization of acute myocardial infarction (AMI). The present study investigated whether the effect of ischemic preconditioning (IPC) against myocardial no-reflow and reperfusion injury was related to the reduction of myocardial edema through the protein kinase A (PKA) pathway.</p><p><b>METHODS</b>Twenty-four minipigs were randomized into sham, AMI, IPC, and IPC + H-89 (PKA inhibitor, 1.0 µg · kg(-1) · min(-1)) groups. The area of no-reflow (ANR), area of necrosis (AN), and water content in left ventricle and ischemic-myocardium and non-ischemic area were determined by pathological studies. Microvascular permeability was determined by FITC-labeled dextran staining. Cardiomyocyte cross-sectional area (CSA) and mitochondria cross-sectional area (MSA) were evaluated by histological analysis. Myocardial expression of aquaporins (AQPs) was detected by Western blot.</p><p><b>RESULTS</b>Compared with the MI group, the sizes of no-reflow and infarct were reduced by 31.9% and 46.6% in the IPC group (all P < 0.01), water content was decreased by 5.7% and 4.6% in the reflow and no-reflow myocardium of the IPC group (all P < 0.05), microvascular permeability and cardiomyocytes swelling in the reflow area were inhibited by 29.8% and 21.3% in the IPC group (all P < 0.01), mitochondrial water accumulation in the reflow and no-reflow areas of the IPC group were suppressed by 45.5% and 34.8% respectively (all P < 0.01), and the expression of aquaporin-4, -8, and -9 in the reflow and no-reflow myocardium were blocked in the IPC group. However, these beneficial effects of IPC were partially abolished in the IPC + H-89 group.</p><p><b>CONCLUSIONS</b>The cardioprotective effects of IPC against no-reflow and reperfusion injury is partly related to the reduction of myocardial edema by inhibition of microvascular permeability and aquaporins up-regulation via PKA pathway.</p>

Effect of antiarrhythmic peptide on ventricular arrhythmia induced by lysophosphatidic acid / 中华心血管病杂志

<p><b>OBJECTIVE</b>To investigate the effect and potential mechanism of lysophosphatidic acid (LPA) and antiarrhythmic peptide (AAP10) on rabbit ventricular arrhythmia.</p><p><b>METHODS</b>Twenty-four rabbits were randomly divided into three groups (n = 8 each): control group, LPA group and AAP10 + LPA group. Using arterially perfused rabbit ventricular wedge preparations, transmural ECG and action potentials from both endocardium and epicardium were simultaneously recorded in the whole process of all experiments with two separate floating microeletrodes. The incidence of ventricular arrhythmia post S1S2 stimulation was recorded. Protein levels of nonphosphorylated Cx43 and total Cx43 were evaluated by Western blot. The distribution of nonphosphorylated Cx43 was observed by confocal immunofluorescence microscopy.</p><p><b>RESULTS</b>Compared with the control group, the QT interval, endocardial action potential duration, transmural repolarization dispersion (TDR) and incidence of ventricular arrhythmia were significantly increased and nonphosphorylated Cx43 expression was significantly upregulated in the LPA group. Compared with the LPA group, cotreatment with AAP10 can reduce the QT interval, endocardial action potential duration, TDR and incidence of ventricular arrhythmia (25.0% vs 62.5%, P < 0.01) and downregulate nonphosphorylated Cx43.</p><p><b>CONCLUSIONS</b>LPA could promote the arrhythmia possibly by upregulating nonphosphorylated Cx43 and subsequent gap junction transmission inhibition. Gap junction enhancer AAP10 could attenuate the pro-arrhythmic effect of LPA probably by downregulating myocardial nonphosphorylated Cx43 expression.</p>