Circulating primary bile acid is correlated with structural remodeling in atrial fibrillation.

BACKGROUND: Circulating primary bile acid was involved in the regulation of cardiac ionic channel currents and ventricular myocyte apoptosis, but it was unknown whether or not it played a role in structural remodeling of AF. This study was aimed to testify the hypothesis that elevated chenodeoxycholic acid (CDCA) concentration correlated with left atrial low voltage area (LVA) and could induce apoptosis of atrial myocytes in AF. METHODS AND RESULTS: Serum concentrations of 12 types of bile acids were determined in patients with paroxysmal (n = 21), persistent AF (n = 20), and type A pre-excitation and paroxysmal supraventricular tachycardia (PSVT) (n = 19) and were correlated with LVA in AF, which was obtained by electroanatomical mapping during ablation. Additionally, the impact of CDCA incubation on apoptosis of mouse atrial myocytes was evaluated. Serum levels of CDCA and cholic acid were significantly higher in AF than in PSVT. CDCA serum concentration was significantly higher in persistent AF than in paroxysmal AF. CDCA serum level was positively correlated with the size (r = 0.78, P < 0.05) and proportion of LVA (r = 0.89, P < 0.05) in AF patients. CDCA (75 µM, 100 µM) promoted atrial myocyte apoptosis in a concentration-dependent manner. CONCLUSIONS: The higher circulating level of CDCA in AF than in PSVT, positive correlation of CDCA with LVA in AF, and incubation dose-dependent increase of mouse atrial myocyte apoptosis indicated that CDCA might play a significant role in the progress of structural remodeling of AF.

[Farnesoid-X-receptor blockade reduces myocardial reperfusion injury in cholesterol-fed apolipoprotein E knockout mice].

OBJECTIVE: To investigate the effect of farnesoid-X-receptor (FXR) antagonist Z-guggulsterone in an in vivo high-fat fed apolipoprotein E knockout (ApoE(-/-)) mice model of myocardial ischemia/reperfusion (I/R). METHODS: Male ApoE(-/-) mice were randomly divided into three groups: standard ApoE(-/-) group (fed with standard mouse diet for 12 weeks before myocardial I/R procedure, n = 18), high-fat ApoE(-/-) group (fed with high-fat mouse diet for 12 weeks before myocardial I/R procedure, n = 22), and high-fat ApoE(-/-) + FXR antagonist group(fed with high-fat mouse diet for 12 weeks and received FXR antagonist Z-Guggulsterone 30 minutes before myocardial I/R procedure, n = 17). The expression of FXR was detected by real-time quantitative-PCR. Myocardial infarct size was determined by Evans blue/TTC double staining methods. Myocardial apoptosis was determined by in situ TUNEL technique. Markers of the mitochondrial-mediated apoptotic pathway (cytochrome c release, caspase-9 activity, and BAX and BCL-2 levels), endoplasmic reticulum stress apoptotic pathway (caspase-12 activity and CHOP level), and death receptor apoptotic pathway (caspase-8 activity, and Fas and FasL levels) were also measured. RESULT: FXR expression (3.7-fold higher, P < 0.01), myocardial infarct size [(62.1 ± 7.0)% vs. (33.8 ± 5.8)%, P < 0.01] and myocardial apoptosis index[ (36.8 ± 5.7)% vs. (17.2 ± 3.8)%, P < 0.01]were all significantly higher in high-fat ApoE(-/-) group than those in standard ApoE(-/-) group. Compared with high-fat ApoE(-/-) group, myocardial infarct size [(24.4 ± 4.7)% vs. (62.1 ± 7.0)%, P < 0.01] and myocardial apoptosis index [(13.8 ± 2.7)% vs. (36.8 ± 5.7)%, P < 0.01] were significantly reduced in high-fat ApoE(-/-) + FXR antagonist group. Moreover, levels of mitochondrial-mediated apoptotic pathway markers (cytochrome c release, caspase-9 activity, and BAX/BCL-2 levels) and endoplasmic reticulum stress apoptotic pathway markers (caspase-12 activity and CHOP level) were significantly lower in high-fat ApoE(-/-) + FXR antagonist group than those in high-fat ApoE(-/-) group (all P < 0.01). Levels of death receptor apoptotic pathway markers (caspase-8 activity, and Fas and FasL levels) were similar between high-fat ApoE(-/-) group and high-fat ApoE(-/-) + FXR antagonist group. CONCLUSION: FXR antagonist alleviates myocardial reperfusion injury in cholesterol-fed ApoE(-/-) mice via inhibition of the mitochondrial-mediated and endoplasmic-reticulum stress pathway.

Pharmacoinvasive therapy for ST elevation myocardial infarction in China: a pilot study.

Most patients with acute ST-elevation myocardial infarction (STEMI) cannot receive timely primary percutaneous coronary intervention (PCI) because of lack of facilities or delays in patient transfer or catheterization team mobilization. In these patients, early routine post-thrombolysis PCI might be a reasonable, useful strategy. This study investigated feasibility and safety of early PCI after successful half-dose alteplase reperfusion in a Chinese population. Patients with STEMI received half-dose alteplase if expected time delay to PCI was ≥90 min. Patients who reached clinical criteria of successful thrombolysis reperfusion were recommended to undergo diagnostic angiography within 3-24 h after thrombolysis. Patients with residual stenosis ≥70% in the infarct-related artery underwent PCI, regardless of flow or patency status. Epicardial arterial flow was assessed using thrombolysis in myocardial infarction (TIMI) flow grade and TIMI frame count (CTFC). Myocardial perfusion was assessed using myocardial blush grade (MBG) and TIMI myocardial perfusion frame count (TMPFC). Forty-nine patients were enrolled and underwent diagnostic angiography 3-11.3 h (median 6.5 h) after thrombolysis. Forty-six patients underwent PCI. No procedure-related complications occurred, except two patients who had no reflow after PCI. Twenty-two (47.8%) patients had TIMI grade 3 flow before PCI and 33 (71.7%) after PCI. CTFC was significantly improved after PCI (48.5 ± 32.1 vs. 37.9 ± 25.6, P = 0.01). MBG and TMPFC exhibited a similar improving trend after PCI, and the best myocardial perfusion tended to be achieved 3-12 h after lysis. During the 30-day follow-up, there were two deaths. The composite end point of death, cardiogenic shock, heart failure, reinfarction, and recurrent ischemia occurred in four patients. TIMI minor bleeding occurred in four patients. No TIMI major bleeding and stroke occurred. Early routine PCI after half-dose alteplase thrombolysis in Chinese population appears feasible. A larger clinical trial should be designed to further elucidate its efficacy and safety. Early PCI after thrombolysis in STEMI: The EARLY-PCI pilot feasibility study, ChiCTR-TNC-11001363.