Polyphenol (-)-epigallocatechin gallate (EGCG), the most abundant catechin of green tea, appears to attenuate myocardial ischemia/reperfusion injury. We investigated the involvement of ATP-sensitive potassium (KATP) channels in EGCG-induced cardioprotection. Isolated rat hearts were subjected to 30 min of regional ischemia and 2 hr of reperfusion. EGCG was perfused for 40 min, from 10 min before to the end of index ischemia. A nonselective KATP channel blocker glibenclamide (GLI) and a selective mitochondrial KATP (mKATP) channel blocker 5-hydroxydecanoate (HD) were perfused in EGCG-treated hearts. There were no differences in coronary flow and cardiodynamics including heart rate, left ventricular developed pressure, rate-pressure product, +dP/dtmax, and -dP/dtmin throughout the experiments among groups. EGCG-treatment significantly reduced myocardial infarction (14.5±2.5% in EGCG 1 µM and 4.0±1.7% in EGCG 10 µM, P<0.001 vs. control 27.2±1.4%). This anti-infarct effect was totally abrogated by 10 µM GLI (24.6±1.5%, P<0.001 vs. EGCG). Similarly, 100 µM HD also aborted the anti-infarct effect of EGCG (24.1±1.2%, P<0.001 vs. EGCG ). These data support a role for the KATP channels in EGCG-induced cardioprotection. The mKATP channels play a crucial role in the cardioprotection by EGCG.
This study showed that, compared with culprit vessel revascularisation, multivessel revascularisation at the time of primary PCI was associated with better outcomes in patients with STEMI with cardiogenic shock. Our results support the current guidelines regarding revascularisation in these patients.
OBJECTIVES
This is an early feasibility clinical test of mitral loop cerclage annuloplasty to treat secondary mitral valve regurgitation.
BACKGROUND
Secondary mitral regurgitation is characterized by cardiomyopathy, mitral annular enlargement, and leaflet traction contributing to malcoaptation. Transcatheter mitral loop cerclage applies circumferential compression to the mitral annulus by creating a loop through the coronary sinus across the interventricular septum, protecting entrapped coronary arteries from compression, and interactive annular reduction under echocardiographic guidance. This is the first human test of mitral loop annuloplasty.
METHODS
Five subjects with severe symptomatic secondary mitral regurgitation underwent mitral loop cerclage, with echocardiographic and computed tomography follow-up over 6 months.
RESULTS
Mitral loop cerclage was successful in 4 of 5 subjects and aborted in 1 of the 5 because of unsuitable septal coronary vein anatomy. Immediately and over 6 months, measures of both mitral valve regurgitation (effective orifice area and regurgitation fraction) and chamber dimensions (left atrial and left ventricular volumes) were reduced progressively and ejection fractions increased. Two with persistent and permanent atrial fibrillation spontaneously reverted to sinus rhythm during follow-up. One subject experienced a small myocardial infarction from an unrecognized small branch coronary occlusion. Another, experiencing cardiogenic shock at baseline, died of intractable heart failure after 6 weeks.
CONCLUSIONS
In this first human test, mitral loop cerclage annuloplasty was successful in 4 of 5 attempts, caused reverse remodeling (reduction in secondary mitral regurgitation and heart chamber volumes), and suggested electrical remodeling (reversion of atrial fibrillation). Further evaluation is warranted.
Superiority of SES over PES during 2 years was attenuated between 2 years and 4 years in diabetic patients. Use of intravascular ultrasound and larger post-procedural minimal lumen diameter were independent predictors of the improved long-term clinical outcomes.
SUMMARYRecent studies have shown that stromal cell derived factor-1 (SDF-1), first known as a cytokine involved in recruiting stem cells into injured organs, confers myocardial protection in myocardial infarction, which is not dependent on stem cell recruitment but related with modulation of ischemia-reperfusion (I/R) injury. However, the effect of SDF has been studied only in a preischemic exposure model, which is not clinically relevant if SDF is to be used as a therapeutic agent. Our study was aimed at evaluating whether or not SDF-1 confers cardioprotection during the reperfusion period. Hearts from SD rats were isolated and perfused with the Langendorff system. Proximal left coronary artery ligation, reperfusion, and SDF perfusion in KH buffer was done according to study protocol. Area of necrosis (AN) relative to area at risk (AR) was the primary endpoint of the study. Significant reduction of AN/AR by SDF in an almost dose-dependent manner was noted during both the preischemic exposure and reperfusion periods. In particular, infusion of a high concentration of SDF (25 nM/L) resulted in a dramatic reduction of infarct size, which was greater than that achieved with ischemic pre-or postconditioning. SDF perfusion during reperfusion was associated with a similar significant reduction of infarct size as preischemic SDF exposure. Further studies are warranted to assess the potential of SDF as a therapeutic agent for reducing I/R injury in clinical practice.
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