Pharmacodynamic Profile and Prevalence of Bleeding Episode in East Asian Patients with Acute Coronary Syndromes Treated with Prasugrel Standard-Dose versus De-escalation Strategy: A Randomized A-MATCH Trial.

Compared with Caucasian patients, East Asian patients have the unique risk-benefit trade-off and different responsiveness to antithrombotic regimens. The aim of this study was to compare pharmacodynamic profile in East Asian patients with acute coronary syndromes (ACSs) treated with prasugrel standard-dose versus a de-escalation strategy. Before discharge, ACS patients with age <75 years or weight ≥60 kg (n = 255) were randomly assigned to the standard-dose (10-mg group) or de-escalation strategy (5-mg group or platelet function test [PFT]-guided group). After 1 month, VerifyNow P2Y12 assay-based platelet reactivity (P2Y12 reaction unit [PRU]) and bleeding episodes were evaluated. Primary endpoint was the percentage of patients with the therapeutic window (85 ≤ PRU ≤ 208). The 250 patients completed 1-month treatment. The percentage of patients within the therapeutic window was significantly lower in the 10-mg group (n = 85) compared with the 5-mg (n = 83) and PFT-guided groups (n = 82) (35.3 vs. 67.5 vs. 65.9%) (odds ratio [OR]: 3.80 and 3.54; 95% confidence interval [CI]: 2.01-7.21 and 1.87-6.69, respectively). Compared with the 10-mg group, the bleeding rate was tended to be lower with de-escalation strategies (35.3 vs. 24.1% vs. 23.2%) (hazard ratio [HR]: 0.58 and 0.55; 95% CI: 0.30-1.14 and 0.28-1.09, respectively). "PRU < 127" was the optimal cut-off for predicting 1-month bleeding events (area under the curve: 0.616; 95% CI: 0.543-0.689; p = 0.005), which criteria was significantly associated with early discontinuation of prasugrel treatment (HR: 2.00; 95% CI: 1.28-3.03; p = 0.001). In conclusion, compared with the standard-dose prasugrel, the prasugrel de-escalation strategy in East Asian patients presented with ACS showed a higher chance within the therapeutic window and a lower tendency toward bleeding episodes. REGISTRATION: URL: https://clinicaltrials.gov. Unique identifier:NCT01951001.

Incidence and clinical impact of early recurrence of atrial tachyarrhythmia after surgical ablation for atrial fibrillation.

BACKGROUND: Atrial tachyarrhythmias (ATAs) are common within the 3-month blanking period after catheter ablation of atrial fibrillation (AF). However, little evidence is available regarding the current guidelines on the blanking period after surgical AF ablation. We investigate the incidence and significance of early recurrence of atrial tachyarrhythmia (ERAT) and evaluate the optimal blanking period after surgical AF ablation. METHODS: Data from 259 patients who underwent surgical AF ablation from 2009 to 2016 were collected. ERAT was defined as documented ATA episodes lasting for 30 s. A multivariate Cox proportional hazard model was constructed to evaluate the role of ERAT as a predictor of late recurrences (LR) for AF. RESULTS: In total, 127 patients (49.0%) experienced their last episodes of ERAT during the first (n = 65), second (n = 14), or third (n = 48) month of the 3-month blanking period (p < .001). One year freedom from ATAs was 97.8% in patients without ERAT compared with 95.4%, 64.3%, and 8.3% in patients with ERAT in the first, second, and third months after the index procedure, respectively (p < .001). Hazard ratios of LR according to the timing of the last episode of ERAT first, second, and third months after the procedure were 2.84, 16.70, and 119.75, respectively. CONCLUSIONS: The ERAT occurred in 49.0% of patients within the first 3 months after surgical ablation. The occurrence of ERAT within 3 months after surgical AF ablation was a significant independent predictor of LR. Hence, the currently accepted 3-month blanking period may be considered for redefining in patients with AF surgical ablation.

Effect of membrane insertion for tricuspid regurgitation using immersed-boundary lattice Boltzmann method.

BACKGROUND: Tricuspid regurgitation is treated by valve repair or replacement. However, these methods have limitations, and alternative treatment methods are therefore required. OBJECTIVES: In this study, a new method of tricuspid valve treatment using artificial membrane insertion is analyzed. We performed tricuspid valve simulations using an artificial membrane inserted into the right ventricle (RV) or right atrium (RA). METHODS: We use the lattice Boltzmann method with the immersed boundary condition to model the structural motion of the valve leaflet. The effect of membrane insertion is analyzed in terms of the stress, force, and impulse on the valve leaflet, along with the velocity, pressure, jet volume, and Reynolds stress in the flow field. RESULTS: While the use of either membrane (RA or RV) leads to improved valve closure relative to the use of no membrane, the RV membrane is more effective than the RA membrane in achieving improved valve closure. In addition, a larger membrane area with a shorter distance between the leaflet and membrane increases membrane efficacy. CONCLUSION: Our results suggest that membrane insertion can form an effective new method for the treatment of tricuspid regurgitation.

Value of Coronary Angiography in the Cardiac Myxoma.

Preoperative coronary angiography for cardiac myxoma not only excludes coronary artery disease but also detects the artery feeding the cardiac myxoma, which has several clinical implications. In this study, we examined cardiac myxoma cases in two tertiary hospitals using coronary angiography to identify the artery feeding the myxoma. We retrospectively reviewed 42 patients with cardiac myxoma who had undergone surgical removal between July 2008 and December 2015 in two tertiary hospitals, and recorded their baseline characteristics, echocardiographic findings, and coronary angiography. Among those 42 patients, 23 (55%) had coronary angiography before surgery and in no case was significant luminal narrowing observed. In 21 of the coronary angiograms, the artery feeding the cardiac myxoma had a vascular branch (100%), clusters of tortuous vessels with contrast medium pooling (67%), an arteriocavity fistula (33%), and a mobile feeding artery (67%). No significant relationship was found between coronary artery dominance type and the origin of the artery feeding the cardiac myxoma (P = 0.362). Identification of the artery feeding the cardiac myxoma, with a distinctive vascular appearance in coronary angiography, is important for several clinical applications such as helping to diagnose cardiac myxoma and to plan the surgical approach. Clin. Anat. 33:833-838, 2020. © 2019 Wiley Periodicals, Inc.

Radiation reduction during percutaneous coronary intervention: A new protocol with a low frame rate and selective fluoroscopic image storage.

The percutaneous coronary intervention (PCI) procedure is associated with potentially high levels of radiation exposure and therefore increased risk of adverse radiation-induced outcomes, ranging from cataract to malignancy. Frame rate reduction and selective fluoroscopy storage may help reduce radiation exposure. In this study, we evaluated the efficacy of a radiation reduction protocol that uses a lower frame rate and selective storage of fluoroscopic images in terms of its effect on reducing the radiation dose during PCI.The new protocol incorporated a lower frame rate as compared with the conventional protocol, and used selective storage of fluoroscopic images. We reviewed the medical records of patients who underwent PCI under the conventional protocol from January 2013 to December 2013, and compared them with those who underwent PCI with the new protocol from January 2015 to December 2015. The primary endpoint was radiation dose reduction expressed as cumulative air kerma and dose-area product (DAP). The image quality was assessed by 3 independent well-trained cardiologists.One hundred fifty-five patients were enrolled in the conventional protocol group, and 152 were enrolled in the radiation reduction protocol group (total, n = 307). There was no statistical significance in terms of the baseline characteristics, including body mass index. Overall, the radiation reduction protocol group showed a significant reduction in both cumulative air kerma (1634.39 ±â€Š717.95 vs 2074.75 ±â€Š1003.72 mGy, P < .001) and DAP (12344.86 ±â€Š5371.75 vs 15312.19 ±â€Š7136.58 µGy m, P < .001). Image quality was acceptable in both groups.The radiation reduction protocol, which uses a lower frame rate and selective storage of fluoroscopic images, may be an alternative approach to reducing PCI radiation dose.

Antiplatelet effect of ticagrelor compared to tirofiban in non-ST-segment elevation ACS patients undergoing PCI. The result of the TE-CLOT trial.

Addition of a potent P2Y12 inhibitor to aspirin is the standard therapy for non-ST-segment elevation acute coronary syndrome (NSTE-ACS) patients undergoing percutaneous coronary intervention (PCI). Glycoprotein IIb/IIIa inhibitor, together with antiplatelet therapy, may be considered as part of initial therapy in NSTE-ACS patients with high-risk features. This study investigated the antiplatelet effect of ticagrelor loading dose (LD) versus tirofiban bolus injection with a post-bolus infusion on top of aspirin among NSTE-ACS patients planned to PCI. NSTE-ACS patients were randomised to receive either ticagrelor (n = 47) or tirofiban (n = 48). Platelet reactivity was assessed by light transmittance aggregometry at 0, 2, 8, and 24 hours (h) after treatment initiation. Primary endpoint was inhibition of platelet aggregation (IPA, 20 µM ADP, final extent) at 2 h after LD therapy, with a non-inferiority margin of 10%. The prevalence of high on-treatment platelet reactivity (HPR) was also compared at 0, 2, 8, and 24 h. The mean difference in IPA between ticagrelor and tirofiban was -9.9% (95% confidence interval: -25.7% to 5.9%) at 2 h, -1.6% (-8.0% to 4.8%) at 8 h, and -3.3% (-18.4% to 12.0%) at 24 h. The prevalence of HPR did not differ between the two groups at any time point (all p values ≥ 0.059), which was almost abolished by 8 h post-LD (< 5%). In conclusion, the antiplatelet effect during the early phase (~2 h) after ticagrelor LD appeared to be relatively strong, but it did not reach that of tirofiban in NSTE-ACS patients.

Radiation Exposure in Coronary Angiography: A Comparison of Cineangiography and Fluorography.

BACKGROUND AND OBJECTIVES: Coronary angiography (CAG) is the gold standard for diagnosing coronary artery disease. However, exposure to ionizing radiation delivered during CAG has various negative biological effects on humans. In this study, there was an evaluation of whether fluorography resulted in decreased radiation exposure, as compared with cineangiography. SUBJECTS AND METHODS: Fifty-five patients were prospectively enrolled and divided into two CAG groups, in accordance with the operator's professional discretion: a conventional cineangiography group versus a fluorography group. Fluorography refers to the photography of fluoroscopic images that are retrospectively stored, e.g., using the "Store fluoro" function of the Siemens cardiac angiography system. The primary outcomes included the air kinetic energy released per unit mass {air kerma (AK) mGy} and the dose (kerma)-area product (DAP; µGy · m(2)), both measured using built-in software in the Siemens system. The secondary outcomes included the total procedure time and amount of contrast agent used with each CAG method. RESULTS: The total AK and DAP were significantly lower in the fluorography group (159.3±64.9 mGy and 1337.9±629.6 µGy · m(2), respectively) than in the cineangiography group (326.9±107.5 mGy and 2341.1±849.9 µGy · m(2), respectively; p=0.000 for both). The total procedure time (cineangiography vs. fluorography, 12.8±4.7 vs. 12.5±2.9 min; p=0.779) and contrast agent amount (136.1±28.3 vs. 126.3±25.7, p=0.214) were comparable between the two groups. CONCLUSION: Fluorography is a useful method to decrease the radiation exposure in selected patients requiring CAG.

High-definition computed tomography for coronary artery stents: image quality and radiation doses for low voltage (100 kVp) and standard voltage (120 kVp) ECG-triggered scanning.

The noninvasive assessment of coronary stents by coronary CT angiography (CCTA) is an attractive method. However, the radiation dose associated with CCTA remains a concern for patients. The purpose of this study is to compare the radiation doses and image qualities of CCTA performed using tube voltages of 100 or 120 kVp for the evaluation of coronary stents. After receiving institutional review board approval, 53 consecutive patients with previously implanted stents (101 stents) underwent 64-slice CCTA. Patients were divided into three different protocol groups, namely, prospective ECG triggering at 100 kVp, prospective ECG triggering at 120 kVp, or retrospective gating at 100 kVp. Two reviewers qualitatively scored the quality of the resulting images for coronary stents and determined levels of artificial lumen narrowing (ALN), stent lumen attenuation increase ratio (SAIR), image noise, and radiation dose parameters. No significant differences were found between the three protocol groups concerning qualitative image quality or SAIR. Coronary lumen attenuation and in-stent attenuation of 100 kVp prospective CCTA (P-CCTA) were higher than in the 120 kVp P-CCTA protocol (all Ps < 0.001). Mean ALN was significantly lower for 100 kVp P-CCTA than for 100 kVp retrospective CCTA (R-CCTA, P = 0.007). The mean effective radiation dose was significantly lower (P < 0.001) for 100 kVp P-CCTA (3.3 ± 0.4 mSv) than for the other two protocols (100 kVp R-CCTA 6.7 ± 1.0 mSv, 120 kVp P-CCTA 4.6 ± 1.2 mSv). We conclude that the use of 100 kVp P-CCTA can reduce radiation doses for patients while maintaining the imaging quality of 100 kVp R-CCTA and 120 kVp P-CCTA for the evaluation of coronary stents.

Remifentanil postconditioning has cross talk with adenosine receptors in the ischemic-reperfused rat heart.

BACKGROUND: Although there is a possibility of cross talk between opioid and adenosine signaling pathways in the ischemic-reperfused myocardium, it is not clear that an ultra-short-acting opioid receptor agonist remifentanil-induced postconditioning (RPostC) has cross talk with adenosine receptor (ADR). The purpose of this study was to determine whether there is cross talk with ADR in RPostC. MATERIALS AND METHODS: Isolated rat hearts were subjected to 30 min of regional ischemia and 2 h of reperfusion. RPostC was induced by 100 ng/mL of remifentanil perfusion, 5 min before reperfusion, followed by 5 min of reperfusion. The nonspecific opioid receptor antagonist naloxone (NAL) and the nonspecific ADR antagonist 8-(p-sulfophenyl) theophylline hydrate (8-SPT) were perfused for a 20-min period, 10 min before RPostC to the end of RPostC. Western blot analysis was performed to detect phospho-ERK1/2 in cultured cardiomyocytes. RESULTS: In cultured cardiomyocytes, remifentanil incubation significantly increased the phosphorylation of ERK1/2 and this effect was blocked by both NAL and 8-SPT (P < 0.01 and P < 0.05, respectively). RPostC significantly reduced infarct size over ischemic area at risk from 34.1 ± 10.5% to 16.6 ± 7.5% (P < 0.05 versus control). The infarct-limitation effect of RPostC was reversed by both NAL (33.8 ± 13.0%, P < 0.05) and 8-SPT (35.7 ± 14.5%, P < 0.01). CONCLUSIONS: This study strongly implies that the intracellular signaling pathways of cardioprotection by RPostC has cross talk with ADR in the ischemic-reperfused myocardium.

Porphyromonas gingivalis HSP60 peptides have distinct roles in the development of atherosclerosis.

Different epitope peptides of bacterial heat shock proteins may function as effector or regulatory molecules in autoimmune responses in infection-triggered atherosclerosis. We investigated the mechanisms for the distinct roles of two epitope peptides from Porphyromonas gingivalis heat shock protein 60 (HSP60) in atherogenesis with regard to peptide-specific T cell polarization relevant to (1) phenotype and cytokine profiles, (2) expression of transcription factors, and (3) role of antigen presenting dendritic cell subsets.Apolipoprotein E-knockout (ApoE KO) mice were immunized with peptide 14 or peptide 19 from P. gingivalis HSP60 prior to induction of atherosclerosis by infection with P. gingivalis plus a Western diet. Significant reductions in plaque/lipid droplet area and plasma cholesterol levels were observed in mice immunized with peptide 14, whereas the opposite phenomenon was evident in mice immunized with peptide 19. CD4+ T-cells polarized to the regulatory T-cell type in peptide 14-immunized group, whereas they polarized to the Th1 cells in peptide 19-immunized group; this observation was supported by the cytokine profiles characteristic to each T-cell phenotype.Significantly higher expression of Nr4a1 and Nr4a2 mRNA, transcriptional factors for regulatory T-cell type, were observed in peptide 14-immunized group. In contrast, the expression level of IFN-γ and T-bet mRNA, signaling molecules for Th1 cells, was higher in peptide 19-immunized group than in PBS-immunized group.In non-immunized wild mice, BMDC-derived CD11c+ dendritic cells have shown to stimulate Tregs significantly in antigen-nonspecific manner. However, each peptide antigen demonstrated a unique mode of preferential adoption of dendritic cell subsets.In conclusion, peptide 14 or peptide 19 from P. gingivalis HSP60, respectively, may play either an anti- or pro-atherogenic role in the ApoE KO mouse model of infection-triggered atherosclerosis through distinct mechanisms operating in the polarization of T cells.

Effects of trimetazidine in patients with acute myocardial infarction: data from the Korean Acute Myocardial Infarction Registry.

BACKGROUND: Excess myocardial fatty acid oxidation can cause a range of deleterious myocardial effects. Trimetazidine (TMZ) is a clinically effective antianginal agent that selectively inhibits long-chain 3-ketoacyl CoA thiolase, reducing fatty acid oxidation and stimulating glucose oxidation. The role of TMZ in acute myocardial infarction (AMI), however, remains unclear. Our retrospective analysis explores the effect on clinical outcomes of adding TMZ to standard treatment in patients with AMI. METHODS: All 13,733 AMI patients registered in the Korean Acute Myocardial Infarction Registry from 2005 to 2008 were retrospectively enrolled. Patients were divided into two groups: those treated with TMZ during their in-hospital management period and those who were not. Primary endpoints were all-cause death combined in-hospital and 12-month death and major adverse cardiac events (MACE), which included all-cause death, recurrent myocardial infarction (MI), repeated percutaneous coronary intervention (PCI) for target lesion revascularization (TLR), and coronary artery bypass graft. Propensity-matched patients were analyzed using an adjusted Cox proportional hazards model. RESULTS: Baseline clinical and angiographic characteristics in the TMZ and no-TMZ groups were generally similar, with the exceptions of pre-PCI thrombolysis in myocardial infarction flow grade, stent type, and stent length. Over 12 months, the relative risk of all-cause death fell by 59 % (event rate 2.3 vs. 6.4 %; hazard ratio 0.41, 95 % CI 0.18-0.97, P = 0.042) and the relative risk of MACE fell by 76 % (event rate 2.3 vs. 9.5 %; hazard ratio 0.24, 95 % CI 0.10-0.56, P = 0.001) in the TMZ group compared with those in the no-TMZ group. CONCLUSIONS: Trimetazidine appeared to improve clinical outcomes in AMI patients by significantly reducing all-cause mortality and MACE over 12 months.

Adenosine-stress low-dose single-scan CT myocardial perfusion imaging using a 128-slice dual-source CT: a comparison with fractional flow reserve.

BACKGROUND: Coronary CT angiography (CCTA) allows accurate evaluation of coronary artery stenosis but has limitations in information on hemodynamic significance of stenotic lesions. PURPOSE: To determine the feasibility of adenosine-stress low-dose single-scan CT myocardial perfusion imaging (MPI) using a 128-slice dual-source CT scanner for the diagnosis of hemodynamically significant coronary artery stenosis as defined by fractional flow reserve (FFR). MATERIAL AND METHODS: This study was proved by the Institutional Review Board and informed consent was obtained from the patients before enrollment in the study. Ninety-seven patients with chest pain and low-to-intermediate pretest probability of coronary artery disease were prospectively enrolled. Adenosine-stress CCTA using ECG-correlated maximum tube current modulation (Mindose(®)) with 128-slice dual-source CT was performed in all 97 patients. In 37 patients (38.1%; 28 men, nine women; mean age, 61.7 ± 20.5 years; mean heart rate, 74.6 ± 2.8 bpm) with significant stenosis at CCTA (lumen diameter reduction >50%), FFR was performed after CCTA, as a reference standard for the evaluation of myocardial perfusion. FFR value ≤0.75 was considered as positive. CTMPI and CCTA were read by two experienced radiologists with consensus, respectively. RESULTS: The effective radiation dose of adenosine-stress single-scan CTMPI was 4.63 ± 2.57 mSv. Compared with FFR, sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for identifying significant coronary stenoses were 93.1%, 82.7%, 75.0%, and 95.6%, respectively, on CCTA and 93.1%, 90.3%, 84.4%, and 95.9%, respectively, on CTMPI. On combined CCTA and CTMPI, sensitivity, specificity, PPV, and NPV were 93.1%, 94.2%, 90.0%, and 96.0%, respectively. CONCLUSION: Adenosine-stress low-dose single scan CTMPI using a 128-slice dual-source CT can provide complementary information on the hemodynamical significance of coronary artery stenosis as well as anatomical information of coronary arteries.

Efficacy of cilostazol on uncontrolled coronary vasospastic angina: a pilot study.

BACKGROUND: Although an angina attack by vasospastic angina (VSA) can usually be relieved or controlled with nitrates and calcium channel blockers (CCBs), there are some patients who cannot be controlled even by higher doses and combinations of these drugs. Cilostazol is a selective inhibitor of phosphodiesterase 3 that increases intracellular cyclic adenosine monophosphate (cAMP) contents. A stimulation of cAMP signal transduction increases coronary nitric oxide production. We examined whether cilostazol improved angina symptoms in patients with VSA uncontrolled by conventional treatment. METHODS: This study was conducted in a prospective, multicenter, nonrandomized manner. The subject consisted of 21 patients (13 men, 57 ± 9 year-old) who were diagnosed with VSA and had at least two angina attacks during the past 1 week despite of conventional medications such as CCBs and/or nitrates. They took cilostazol 100 mg twice daily for 2 weeks in addition to the conventional medications. The patients recorded the frequency of angina attack and wrote down the numeric rating scale of a "severity of angina attack" while taking conventional medications and cilostazol for 2 weeks, and also recorded an averaged scale or total number of event during the last week at the time of the assessment. Using the Wilcoxon rank-sum test, we compared the changes in the scores of frequency and severity of angina attack before and after adding cilostazol to the conventional medications. RESULTS: After adding cilostazol to the conventional medications, there were 78.9% relative reduction of the score of angina intensity and 73.5% of angina frequency (P < 0.001). There were four patients (19%) who were forced to stop cilostazol due to headache as an adverse event. CONCLUSIONS: Cilostazol appears to be an effective therapy in VSA uncontrolled with conventional medical treatment. A further prospective, randomized, placebo-controlled study will be needed to validate this result.

Polyphenol (-)-epigallocatechin gallate-induced cardioprotection may attenuate ischemia-reperfusion injury through adenosine receptor activation: a preliminary study.

BACKGROUND: The activation of guanine nucleotide binding protein-coupled receptors, such as adenosine receptor (ADR) and opioid receptor (OPR), protects the heart against ischemia and reperfusion injury. We hypothesized that ADR or OPR might be involved in polyphenol (-)-epigallocatechin gallate (EGCG)-induced cardioprotection. METHODS: Langendorff perfused rat hearts were subjected to 30 min of regional ischemia and 2 h of reperfusion. Hearts were treated with 10 µM of EGCG, with or without the ADR or OPR antagonist at early reperfusion. Infarct size measured with 2,3,5-triphenyltetrazolium chloride staining was chosen as end-point. RESULTS: EGCG significantly reduced infarct volume as a percentage of ischemic volume (33.5 ± 4.1%) compared to control hearts (14.4 ± 1.1%, P < 0.001). A nonspecific ADR antagonist 8-(p-sulfophenyl) theophylline hydrate (27.1 ± 1.9%, P < 0.05 vs. EGCG) but not a nonspecific OPR antagonist naloxone (14.3 ± 1.3%, P > 0.05 vs. EGCG) blocked the anti-infarct effect by EGCG. The infarct reducing effect of EGCG was significantly reversed by 200 nM of the A(1) ADR antagonist DPCPX (25.9 ± 1.1%, P < 0.05) and 15 nM of the A(2B) ADR antagonist MRS1706 (29.3 ± 1.7%, P < 0.01) but not by 10 µM of the A(2A) ADR antagonist ZM241385 (23.9 ± 1.9%. P > 0.05 vs. EGCG) and 100 nM of the A(3) ADR antagonist MRS1334 (24.1 ± 1.8%, P > 0.05). CONCLUSIONS: The infarct reducing effect of EGCG appears to involve activation of ADR, especially A(1) and A(2B) ADR, but not OPR.

Pressure-wire based assessment of microvascular resistance using calibrated upstream balloon obstruction: a predictor of myocardial viability.

OBJECTIVES: We assess microvascular integrity as a marker of myocardial viability after coronary stenting, using only a pressure guidewire. BACKGROUND: Microvascular integrity generally is not assessed using pressure-only guidewires because the transducer lies upstream of microvasculature. We partially inflate a balloon inside a coronary stent to achieve a specific normalized pressure drop at rest (distal coronary/aortic pressure = 0.8) and then infuse a vasodilator, to render the wire sensitive to microvascular function. We hypothesize that the further decline in pressure (ΔFFR(0.8) ) predicts MRI myocardial viability. METHODS: We studied 29 subjects with acute coronary syndrome including myocardial infarction. After successful culprit stenting, the resting coronary/aortic pressure was set to 0.8 using temporary balloon obstruction. ΔFFR(0.8) was defined as 0.8-(distal coronary/aortic pressures) during adenosine-induced hyperemia. The average transmural extent of infarction was defined as the average area of MRI late gadolinium enhancement (after 2.8 ± 1.5 days) divided by the corresponding full thickness of the gadolinium enhanced sector in short axis slices, and was compared with ΔFFR(0.8) . RESULTS: ΔFFR(0.8) corresponded inversely and linearly with the average transmural extent of infarction (r(2) = 0.65, P < 0.001). We found that a transmural extent of infarction of 0.50 corresponded to a ΔFFR(0.8) threshold of 0.1, and had high sensitivity and specificity (100% and 94.4%, respectively). CONCLUSIONS: Using only an upstream pressure-sensitive guidewire and a partially obstructing balloon during pharmacologic hyperemia, we were able to predict MRI myocardial viability with high accuracy after relief of epicardial stenosis. With further validation, this may prove a useful clinical prognostic tool after percutaneous intervention.

Step-and-shoot prospectively ECG-gated vs. retrospectively ECG-gated with tube current modulation coronary CT angiography using 128-slice MDCT patients with chest pain: diagnostic performance and radiation dose.

BACKGROUND: With increasing awareness for radiation exposure, the study of diagnostic accuracy of coronary CT angiography (CCTA) with low radiation dose techniques is mandatory to both radiologist and clinician. PURPOSE: To compare diagnostic performance and effective radiation dose between step-and-shoot prospectively ECG-gated and retrospectively ECG-gated with tube current modulation (TCM) CCTA using 128-slice multidetector computed tomography (MDCT). MATERIAL AND METHODS: We retrospectively evaluated 60 patients who underwent CCTA with either of two different low-dose techniques using 128-slice MDCT (23 patients for step-and shoot-prospectively ECG-gated and 37 patients for retrospectively ECG-gated with TCM CCTA) followed by conventional coronary angiography. All coronary arteries and all segments thereof, except anatomical variants or small size (< 1.5 mm) ones, were included in analysis. RESULTS: In per-segment analysis, sensitivity, specificity, positive predictive value, and negative predictive value were 91/96%, 95/94%, 75/73%, and 98/99% for step-and-shoot prospectively ECG-gated and retrospectively ECG gated with TCM CCTA, respectively, relative to conventional coronary angiography. Effective radiation dose were 1.75 ± 0.83 mSv, 4.91 ± 1.71 mSv in the step-and-shoot prospectively ECG-gated and retrospectively ECG-gated with TCM CCTA groups, respectively. CONCLUSION: The two low-radiation dose CCTA techniques using 128-slice MDCT yields comparable diagnostic performance for coronary artery disease in symptomatic patients with low heart rates.

Polyphenol (-)-epigallocatechin gallate targeting myocardial reperfusion limits infarct size and improves cardiac function.

BACKGROUND: This experiment was performed to determine the effect of polyphenolic (-)-epigallocatechin (EGCG), the most abundant catechin of green tea, given at reperfusion period. METHODS: Isolated rat hearts were subjected to 30 min of regional ischemia and 2 h of reperfusion. Green tea extract (GT) was perfused with the following concentrations; 0, 0.5, and 1 microM (GT-O, GT-0.5, and GT-1, respectively). In a next experiment, hearts were assigned randomly to one of the following groups; Control, EGCG-1 (1 microM of EGCG), and EGCG-10 (10 microM of EGCG). GT and EGCG were perfused for a period of 5 min before and 30 min after reperfusion. For comparison of cardioprotection among groups, morphometric measurement was performed by 2,3,5-triphenyltetrazolium chloride staning. RESULTS: GT 1 microM (10.3 +/- 2.1%, P < 0.05) significantly reduced infarct volume as a percentage of ischemic volume compared to untreated hearts (27.4 +/- 1.1%). EGCG 10 microM (13.2 +/- 4.0%) significantly reduced myocardial infarction compared to control hearts (27.2 +/- 1.4%, P = 0.002). After 2 h of reperfusion, cardiodynamic variables, including left ventricular developed pressure, rate-pressure produce, +dP/dt(max), and -dP/dt(min) were significantly improved by 10 microM of EGCG compared to control hearts (P = 0.01, 0.016, 0.009, and 0.019, respectively). CONCLUSIONS: EGCG treatment at an early reperfusion period reduces myocardial infarction and improves cardiodynamics in isolated rat hearts.

Polyphenol (-)-epigallocatechin gallate during ischemia limits infarct size via mitochondrial K(ATP) channel activation in isolated rat hearts.

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 (K(ATP)) 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 K(ATP) channel blocker glibenclamide (GLI) and a selective mitochondrial K(ATP) (mK(ATP)) 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/dt(max), and -dP/dt(min) throughout the experiments among groups. EGCG-treatment significantly reduced myocardial infarction (14.5+/-2.5% in EGCG 1 microM and 4.0+/-1.7% in EGCG 10 microM, P<0.001 vs. control 27.2+/-1.4%). This anti-infarct effect was totally abrogated by 10 microM GLI (24.6+/-1.5%, P<0.001 vs. EGCG). Similarly, 100 microM 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 K(ATP) channels in EGCG-induced cardioprotection. The mK(ATP) channels play a crucial role in the cardioprotection by EGCG.

Mitral cerclage annuloplasty, a novel transcatheter treatment for secondary mitral valve regurgitation: initial results in swine.

OBJECTIVES: We developed and tested a novel transcatheter circumferential annuloplasty technique to reduce mitral regurgitation in porcine ischemic cardiomyopathy. BACKGROUND: Catheter-based annuloplasty for secondary mitral regurgitation exploits the proximity of the coronary sinus to the mitral annulus, but is limited by anatomic variants and coronary artery entrapment. METHODS: The procedure, "cerclage annuloplasty," is guided by magnetic resonance imaging (MRI) roadmaps fused with live X-ray. A coronary sinus guidewire traverses a short segment of the basal septal myocardium to re-enter the right heart where it is exchanged for a suture. Tension is applied interactively during imaging and secured with a locking device. RESULTS: We found 2 feasible suture pathways from the great cardiac vein across the interventricular septum to create cerclage. Right ventricular septal re-entry required shorter fluoroscopy times than right atrial re-entry, which entailed a longer intramyocardial traversal but did not cross the tricuspid valve. Graded tension progressively reduced septal-lateral annular diameter, but not end-systolic elastance or regional myocardial function. A simple arch-like device protected entrapped coronary arteries from compression even during supratherapeutic tension. Cerclage reduced mitral regurgitation fraction (from 22.8 +/- 12.7% to 7.2 +/- 4.4%, p = 0.04) by slice tracking velocity-encoded MRI. Flexible cerclage reduced annular size but preserved annular motion. Cerclage also displaced the posterior annulus toward the papillary muscles. Cerclage introduced reciprocal constraint to the left ventricular outflow tract and mitral annulus that enhanced leaflet coaptation. A sample of human coronary venograms and computed tomography angiograms suggested that most have suitable venous anatomy for cerclage. CONCLUSIONS: Transcatheter mitral cerclage annuloplasty acutely reduces mitral regurgitation in porcine ischemic cardiomyopathy. Entrapped coronary arteries can be protected. MRI provided insight into the mechanism of cerclage action.