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Purpose To develop MR-tracked catheters to delineate the three-dimensional motion of coronary arteries at high spatial and temporal resolution. Materials and Methods Catheters with three tracking microcoils were placed into nine swine. During breath-holds, electrocardiographic (ECG)-synchronized 3D motion was measured at varying vessel depths. 3D motion was measured in American Heart Association left anterior descending (LAD) segments 6–7, left circumflex (LCX) segments 11–15, and right coronary artery (RCA) segments 2–3, at 60–115 beats/min heart rates. Similar-length cardiac cycles were averaged. Intercoil cross-correlation identified early systolic phase (ES) and determined segment motion delay. Results Translational and rotational motion, as a function of cardiac phase, is shown, with directionality and amplitude varying along the vessel length. Rotation (peak-to-peak solid-angle RCA ≈0.10, LAD ≈0.06, LCX ≈0.18 radian) occurs primarily during fast translational motion and increases distally. LCX displacement increases with heart rate by 18%. Phantom simulations of motion effects on high-resolution images, using RCA results, show artifacts due to translation and rotation. Conclusion Magnetic resonance imaging (MRI) tracking catheters quantify motion at 20 fps and 1 mm3 resolution at multiple vessel depths, exceeding that available with other techniques. Imaging artifacts due to rotation are demonstrated. Motion-tracking catheters may provide physiological information during interventions and improve imaging spatial resolution. J. Magn. Reson. Imaging 2009;29:86–98. © 2008 Wiley-Liss, Inc.

The aim of this study was to determine whether severe mitral regurgitation (MR) is progressive and whether tissue-Doppler (TD)-derived indexes can detect early left ventricular (LV) dysfunction in chronic severe MR. Percutaneous rupture of mitral valve chordae was performed in pigs ( n = 8). Before MR (baseline), immediately after MR (post-MR), and at 1 and 3 mo after MR, cardiac function was assessed using conventional and TD-derived indexes. The severity of MR was quantified using regurgitant fraction and effective regurgitant orifice area (EROA). In all animals, MR was severe. On follow-up, the LV dilated progressively over time, but LV ejection fraction did not decrease. With the increase in LV dimensions, the forward stroke volume remained unchanged, but the mitral annular dimensions, EROA, and regurgitant fraction increased (EROA = 41 ± 2 and 51 ± 2 mm2 post-MR and at 3 mo, respectively, P < 0.01). Peak systolic myocardial velocities, strain, and strain rate increased acutely post-MR and remained elevated at 1 mo but declined by 3 mo (anterior strain rate = 2.9 ± 0.1 and 2.4 ± 0.2 s−1 post-MR and at 3 mo, respectively, P < 0.001). Therefore, in a chronic model of MR, serial echocardiography demonstrated that MR begets MR and that those TD-derived indexes that initially increased post-MR decreased to baseline before any changes in LV ejection fraction.

1995年に国民医療保険制度（NHI）を導入した事は，台湾の社会保険制度にとって記念碑的出来事であった。台湾は多くの事を日本から学んだが，NHIは，単一支払者制度，総額予算支払制度（總額預算支付制度）を採用し，様々なIT技術を用いている点で，日本の制度を更に進めたものになっている。この論文は，NHI創設以降の，NHIの発展，主要な政策論争，パフォーマンス，将来の課題について，出来る限り公平に論評したものである（1995-2006年）。 過去12年間の結果の評価に関しては，保険の加入率の向上，市民が医療を受ける為の経済的障壁の減少，医療へのアクセスの改善について，はっきりとした成果を残した。コストの抑制に関しては，国民医療費のGDPに占める割合は5.29-6.09％に保たれ，1995-2006年のほとんどの時期，国民医療費は経済成長とほぼ同じ割合で増加した。 主要な改革として２つの方向が示されている。先ず，財政的継続可能性と公平の観点から，単一の加入制度に向けた基金の改革が提案されている。提案の主要素は３つである。(1)加入者をこれ以上分類しない。(2)保険加入者，雇用主，政府の三者間で保険料負担を分担する制度を維持する。(3)年間の保険料を総額予算の交渉とリンクさせ，世帯収入に従って保険料の自己負担分を分担する。更に，医療の質の改善の為に，現在改革に向けたパイロットプロジェクトとして行われている入院患者へのDRGs，外来患者への家庭医総合診療制度，医療の質に基づく支払制度を，総額予算支払制度の土台の上に，調和し，拡張することが提案されている。

There are few data comparing the fate of multipotent progenitor cells (MPCs) used in cardiac cell therapy after myocardial infarction (MI). To document in vivo distribution of MPCs delivered by intracoronary (IC) injection.Using an anterior MI swine model, near-infrared (NIR) fluorescence was used for in vivo tracking of labelled MPCs [mesenchymal stromal (MSCs), bone marrow mononuclear (BMMNCs), and peripheral blood mononuclear (PBMNCs)] cells early after IC injection. Signal intensity ratios (SIRs) of injected over non-injected (reference) zones were used to report NIR fluorescence emission. Following IC injection, significant differences in mean SIR were documented when MSCs were compared with BMMNCs [1.28 +/- 0.10 vs. 0.77 +/- 0.11, P0.001; 95% CI (0.219, 0.805), respectively] or PBMNCs [1.28 +/- 0.10 vs. 0.80 +/- 0.14, P = 0.005; 95% CI (0.148, 0.813), respectively]. Differences were maintained during the 60 min tracking period, with only the MSC-injected groups continuously emitting NIR fluorescence (SIR1). This is correlated with greater cell retention for MSCs relative to mononuclear cells. However, there was evidence of MSC-related vessel plugging in some swine.Our in vivo NIR fluorescence findings suggest that MPC distribution and retention immediately after intracoronary delivery vary depending on cell population and could potentially impact the clinical efficacy of cardiac cell therapy.

Atheroemboli caused by aortic manipulation poses a risk for stroke in patients undergoing cardiopulmonary bypass (CPB) surgery. One potential cause is the high velocity jet from aortic perfusion cannulae. This study describes the flow patterns of a novel funnel-tip cannula designed to reduce emboli by decreasing fluid velocity and resultant shear force on the aortic wall.A funnel-tip cannula was constructed and compared with standard straight-tip cannulae and the Dispersion (Research Medical Inc, Midvale, UT) and Sarns Soft Flow (Terumo Cardiovascular Systems Corp, Ann Arbor, MI) cannulae. Pressure drop measurements were collected at 1 to 6 L/minute flows. Velocity flow profiles were created using phase contrast magnetic resonance imaging. Absolute velocity was measured in a phantom aorta at 5 L/minute flow. Each cannula was further studied in a synthetic model of an atherosclerotic aorta to determine the mass of dislodged particulate matter generated at 2, 3, and 5 L/minute flows.The funnel-tip cannula demonstrated significantly lower values (p0.05) in pressure drop (55 mm Hg), exit velocity (309 cm/second, 167 cm/second for center axis and wall, respectively), and particulate dislodgement (0.15 +/- 0.05 g) than other tested cannulae. The Soft Flow cannula generated the next lowest pressure drop but exhibited twice the exit velocity and particulate dislodgement of the funnel-tip cannula. The Dispersion cannula did not demonstrate a reduction in velocity or particulate dislodgement compared with the standard straight-tip cannulae.The results of this study suggest that a low-angled funnel-tip cannula has favorable flow characteristics warranting further investigation. Design development may reduce the risk of atheroemboli generation during CPB surgery.

Background: Cardiac cell-based therapy (CCT) has emerged as a promising therapeutic strategy. There are few data comparing the fate of different stem cell (SC) populations delivered by the intracoronary injection (ICI). Aim: Document the in vivo myocardial distribution of SC delivered by ICI following recent myocardial infarction. Methods: In a myocardial infarction swine model, near-infrared (NIR) fluorescence was used to provide high sensitivity in vivo tracking of SC in the immediate phase (< 60 minutes) after ICI of 2x107 cells. After labeling with the NIR fluorophore, IR-786, the NIR signal intensities and myocardial distribution patterns of mesenchymal (MSC), bone marrow-(BMMNC) and peripheral blood-mononuclear (PBMNC) cells were compared using an open-chested fluorescence imaging system. Results: The SC populations of interest were successfully loaded with IR-786. While all SC populations readily distributed along the vascular territory of the infarct-related artery immediately after injection, there was a mean SI intensity drop of 29.8% and 14.1% for PBMNC and BMNC (p ). Conclusion: Our in vivo findings suggest that immediately after injection (during the first 60min ICI), there is already evidence of poor SC retention and distribution vary depending on cell population, potentially impacting clinical efficacy and safety of CCT.

Background: Reduced activity and expression of sarcoplasmic reticulum Ca 2+ ATPase (SERCA2a) is known to occur in HF. Method: Our 4-month study examined the effects of SERCA2a gene transfer in a swine volume-overload HF (VO-HF) model. Using Yorkshire-Landrace swine, HF was created by severing mitral apparatus chordae to induce mitral regurgitation. Results: At 2 months (M), a compensated state of VO-HF was found: prolongation of the rate of isovolumic relaxation (Tau), increased left ventricular internal diameter diastolic and systolic diameters (LVIDd, LVIDs). At 2M, intracoronary injection of adeno-associated virus serotype 1 vector carrying SERCA2a under a cytomegalovirus promoter (AAV1.SERCA2a) (n = 10) vs. saline (n = 6) was performed. At 4M, gene transfer resulted in (A) positive LV inotropic effects: (dP/dt)/P, 15.5 ± 3.0 sec − 1 SERCA2a-group vs. 21.2 ± 3.2 sec − 1 controls; p < 0.01; (B) a favorable trend in LV lusitropic effects: Tau, 0.037 ± 0.019 vs. 0.051 ± 0.01 msec, p = 0.09; (C) improvement in LV geometry: % change in LVIDs, +15 ± 11% controls vs. −3.0 ± 10% SERCA2a-group, p < 0.01. At 4M, BNP levels remained stable in post- SERCA2a gene transfer, in contrast to the progressive rising levels among controls. Further, cardiac SERCA2a expression was significantly decreased in controls whereas it was restored to normal levels in the SERCA2a group (Figure ). Lastly, there was no histopathological evidence of myocardial inflammatory reaction or necrosis. Conclusion: Overexpression of SERCA2a by in vivo AAV1-mediated intracoronary gene transfer preserved systolic function, potentially prevented diastolic dysfunction and improved ventricular remodeling.

Heart failure is a major cause of morbidity and mortality in contemporary societies. Although progress in conventional treatment modalities is making steady and incremental gains to reduce this disease burden, there remains a need to explore new and potentially therapeutic approaches. Gene therapy, for example, was initially envisioned as a treatment strategy for inherited monogenic disorders. It is now apparent that gene therapy has broader potential that also includes acquired polygenic diseases, such as heart failure. Advances in the understanding of the molecular basis of conditions such as these, together with the evolution of increasingly efficient gene transfer technology, has placed congestive heart failure within reach of gene-based therapy.

Gelatin hydrogel microspheres (GHMs) have been reported as novel non-viral vectors for gene or protein delivery (GHM therapy). However, the components of an effective catheter-based delivery strategy for GHM therapy are unknown. We evaluated the effectiveness of three catheter-based strategies for cardiac GHM therapy: (1) antegrade injection (AI) via coronary arteries; (2) retrograde injection (RI) via coronary veins; and (3) direct myocardial injection (DI) via the coronary sinus. AI distributed microspheres homogeneously throughout the target area with 73+/-11% retention. RI scattered microspheres non-homogenously with 22+/-8% retention. DI distributed microspheres in the needle-advanced area with 47+/-14% retention. However, despite high efficiency, AI did not show biological effects of inducing angiogenesis from basic fibroblast growth factor bound to GHMs. Furthermore, focal micro-infarctions, owing to micro-embolism of aggregated GHMs into small coronary arterioles, were detected in the AI group. Conversely, only RI and DI groups displayed increased coronary flow reserve. DI groups also demonstrated increased capillary density. These results suggest that RI and DI are effective for cardiac GHM therapy, while AI appears inappropriate owing to the risk of focal infarctions.

Background: In recent years, animal studies and clinical trials have highlighted the regenerative potential of cardiac cellular therapy in the setting of both myocardial infarction and heart failure. Understanding the fate of stem/progenitor cells (SPCs) transplanted in the injured myocardium remains a pivotal issue in this field. In light of recent advances in molecular imaging, near-infrared (NIR) imaging represents a promising approach for cellular labeling and tracking of grafted SPCs. Therefore, we hypothesized that NIR labeling and in vivo tracking of SPCs is feasible and will allow to document their biological fate. Methods: Bone marrow derived meschenchymal stem cells (BMMSCs) were isolated from Yorkshire swines (n=3), and cultured for 2 weeks. Myocardial infarction was induced in all swines by 60-minute balloon occlusion of the left anterior descending artery. On day 3 post-infarction, allogenic BMMSCs (average, 20|[times]|106 cells): 1) underwent cellular labeling with the dye IR-786; 2) were reinjected in the infarct artery via intracoronary injection. Cellular labeling was assessed as follow: IR-786 labeled BMMSCs were tracked with a unique in vivo fluorescence/NIR imaging system under open chest condition. Results: BMMSCs were successfully labeled with IR-786 with near 100% efficiency. Over 90 % of BMMSCs were viable following IR-786 labeling. At baseline, the NIR signal-to-background ratio (SBR) was 1 in the infarct artery territory. Following cell injection, SBRs of the latter territory promptly increased by 3 to 5 fold (Figs 1). The SBRs remained sufficiently elevated to permit tracking of BMMSCs distributions even at the time of 60 min after the injection. These data will be discussed in conjunction with microscopic assessment of NIR labeled cells at the time of presentation. Conclusion: In vivo NIR imaging offers a new option to scrutinize reinjected cells. Cellular labeling of BMMSCs with IR786 is feasible; as well it allows both studying and appropriate tracking of the biological fate of transplanted SPCs in the setting of myocardial infarction.

Hayase, Motoya, Federica del Monte, Yoshiaki Kawase, Brian D. MacNeill, Jennifer McGregor, Ryuichi Yoneyama, Kozo Hoshino, Tsuyoshi Tsuji, Alec M. De Grand, Judith K. Gwathmey, John V. Frangioni, and Roger J. Hajjar. Catheter-based antegrade intracoronary viral gene delivery with coronary venous blockade. Am J Physiol Heart Circ Physiol 288: H2995–H3000, 2005; doi:10.1152/ajpheart.00703.2004.—The purpose of this study is to evaluate the feasibility of percutaneous antegrade myocardial gene transfer (PAMGT). A consistent and safe technique for in vivo gene transfer is required for clinical application of myocardial gene therapy. PAMGT with concomitant coronary venous blockade was performed in 12 swine. The myocardium was preconditioned with 1 min of occlusion of the left anterior descending and left circumflex arteries. The anterior interventricular vein was occluded during left anterior descending artery delivery, and the great cardiac vein at the entrance of the middle cardiac vein was occluded during left circumflex artery delivery. With arterial and venous balloons inflated (3 min) and after adenosine (25 μg) injection, PAMGT was performed by antegrade injection of an adenoviral solution (1 ml of 1011 plaque-forming units in each coronary artery) carrying β-galactosidase or saline through the center lumen of the angioplasty balloon. In one set of animals, PAMGT was performed with selective coronary vein blockade (n = 9); in another set of animals, PAMGT was performed without coronary vein blockade (n = 5). At 1 wk after gene delivery, the animals were killed. Quantitative β-galactosidase analysis was performed in the left and right ventricular walls. PAMGT was successfully performed in all animals with and without concomitant occlusion of the coronary veins. Quantitative β-galactosidase analysis showed that PAMGT with coronary blockade was superior to PAMGT without coronary blockade. β-Galactosidase activity increased significantly in the β-galactosidase group compared with the saline group: 1.34 ± 0.18 vs. 0.81 ± 0.1 ng (P ≤ 0.01) in the left ventricular wall and 0.91 ± 0.1 vs. 0.66 ± 0.07 ng (P ≤ 0.05) in the right ventricular wall. PAMGT with selective coronary venous blockade is feasible, reproducible, and safely achieved in a large-animal model.

Top of pageAbstract Introduction: The kinetics of long term transgene expression of viral vectors is important as it directly influences the efficacy of the gene therapy. Conventional kinetic measurements require sacrificing animals at each data point and assessing the amount of transgene product in the tissue. This type of analysis is extremely laborious and contains inherent inaccuracy since it does not follow the time course of a single animal. In this study, in vivo tracking of transgene expression from adeno-aasociated virus type 1 (AAV-1) was performed using a green fluorescence protein (GFP) reporter and an specially designed optical imaging system.. Our results reveal the exact kinetics of AAV-1 expression and validate fluorescence imaging for kinetic measurements of long term expression of virally expressed genes. Materials and Method: Animals and Virus 40-day-old male hairless SKH1 mice were divided into 3 groups, each containing 3 mice. The right leg of Groups 1 and 2 were injected with 1012 and 1010 plaque forming unit (pfu) of adeno-associated virus type 1 encoding green fluorescent protain (AAV-1.GFP). respectively, in 50 ul normal saline. The left legs were injected with 50 ul normal saline as an internal control. Group 3 (control group) was injected with 50 ul normal saline into the both legs. The mice were anesthetized by intraperitoneal injection of 80 mg/kg body weight ketamine at the time of each measurement, and imaged over 13 weeks. Imaging System Selective excitation of GFP was produced by 475 nm light emission diode through a excitation filter HQ470/40x. Emitted fluorescence was collected through an emission filter HQ525/50m (Chroma Technology Corp, Rockingham, VT) on a Hamamatsu C8484 charge-coupled device camera (Hamamatsu Photonics Systems, Bridgewater, NJ). The strength of the transgene expression was measured as the ratio of the mean of fluorescence intensity of 0.5 cm2 ROI set on the right and left leg. Results and Conclusions The kinetics of GFP expression was clearly measured by assessing the fluorescence intensity of each animal. The images and graphs of representative animals are shown in the Figure. In Group 1, injected with 1012 pfu AAV-1.GFP, GFP expression reached a plateau at approximately 7 weeks, which was maintained until at least 13 weeks. In Group 2, injected with 1010 pfu AAV-1.GFP, GFP expression, reached its plateau at approximately 11 weeks. These results demonstrate the relationship between injected dose and transgene expression level, as well as the kinetics of expression.

Bone marrow mesenchymal stem cells (MSCs) have been used for myocardial regeneration. The fate of injected cells and mechanism of their therapeutic benefits are unclear and cardiomyocytic differentiation is limited. We examined the gene expression of autologous MSCs injected into pig myocardium to assess the biologicprocesses involved.

Top of pageAbstract Background: The acute overexpression of sarcoplasmic reticulum calcium ATPase (SERCA2a) by gene transfer has been shown to restore normal contractile function in rodent models of heart failure and is a promising therapy for chronic heart failure. However the long-term efficacy has not been cleared yet in a large animal model. Objectives: The aim of this study is to examine the long-term efficacy of SERCA2a gene expression in a porcine model of heart failure. Methods: A total 13 animals underwent rupture of posterior mitral valve chordae to create severe mitral valve regurgitation (MR) using a percutaneous approach. Four pigs died after MR creation. Nine pigs with MR were then divided into two groups: Group 1 (n=5): Treated with adeno-associated virus type 6 (AAV6) encoding SERCA2a under the control of a CMV promoter and Group 2 (n=4): Treated with AAV6 encoding for b-galactosidase (bgal). Viral solution containing 5|[times]|1013 genomes/ml was injected through coronary artery with coronary vein occlusion 1 month after MR creation. Left ventricular (LV) function was examined 1 month and 3 month after MR creation by echo and hemodynamics data. Results: The comparison of echo data between 1 month and 3 month after MR creation showed significant dilatation of left ventricular end-diastolic dimension (LVEDD) (51.8|[plusmn]|3.7 vs 56.9|[plusmn]|6.8; p

Background: Biodegradable Gelatin hydrogel microsphere (GHM) has been reported as a novel non-viral vehicle for gene or protein therapy. However, it is unknown what catheter-based strategy is effective for the GHM delivery to the heart.

International audience; Objectives The aim of this study was to examine the effects of sarcoplasmic reticulum Ca2+ ATPase (SERCA2a) gene transfer in a swine heart failure (HF) model.Background Reduced expression and activity of SERCA2a have been documented in HF. Prior studies have reported the beneficial effects of short-term SERCA2a overexpression in rodent models. However, the effects of long-term expression of SERCA2a in pre-clinical large animal models are not known. Methods Yorkshire-Landrace pigs were used (n = 16) to create volume overload by percutaneously severing chordae tendinae of the mitral apparatus with a bioptome to induce mitral regurgitation. At 2 months, pigs underwent intracoronary delivery of either recombinant adeno-associated virus type 1 (rAAV1) carrying SERCA2a under a cytomegalovirus promoter (rAAV1.SERCA2a) (n = 10; group 1) or saline (n = 6; group 2). Results At 2 months, study animals were found to be in a compensated state of volume-overload HF (increased left ventricular internal diastolic and systolic diameters [LVIDd and LVIDs]). At 4 months, gene transfer resulted in: 1) positive left ventricular (LV) inotropic effects (adjusted peak left ventricular pressure rate of rise (dP/dt)max/P, 21.2 ± 3.2 s−1 group 1 vs. 15.5 ± 3.0 s−1 group 2; p < 0.01); 2) improvement in LV remodeling (% change in LVIDs −3.0 ± 10% vs. +15 ± 11%, respectively; p < 0.01). At follow-up, brain natriuretic peptide levels remained stable in group 1 after gene transfer, in contrast to rising levels in group 2. Further, cardiac SERCA2a expression was significantly decreased in group 2 whereas in group 1 it was restored to normal levels. There was no histopathological evidence of acute myocardial inflammation or necrosis. Conclusions Using a large-animal, volume-overload model of HF, we report that long-term overexpression of SERCA2a by in vivo rAAV1-mediated intracoronary gene transfer preserved systolic function, potentially prevented diastolic dysfunction, and improved ventricular remodeling.