Safety and effectiveness of the phoenix atherectomy device for endovascular treatment of common femoral and popliteal arteries: Results of the EN-MOBILE trial.

Background: This study aimed to assess the peri- and postprocedural outcomes of atherectomy-assisted endovascular treatment of the common femoral (CFA) and popliteal arteries. Methods: Phoenix atherectomy was used for the treatment of 73 and 53 de novo CFA and popliteal artery lesions, respectively, in 122 consecutive patients. Safety endpoints encompassed perforation and peripheral embolization. Postprocedural endpoints included freedom from clinically driven target lesion revascularization (CD-TLR) and clinical success (an improvement of ⩾ 2 Rutherford category [RC]). In addition, 531 patients treated for popliteal artery stenosis or occlusion without atherectomy were used as a comparator group. Results: Procedural success (residual stenosis < 30% after treatment) was 99.2%. The need for bail-out stenting was 2 (2.7%) and 3 (5.7%) in CFA and popliteal artery lesions, respectively. Only one (1.4%) embolization occurred in the CFA, which was treated by catheter aspiration. No perforations occurred. After 1.50 (IQR = 1.17-2.20) years, CD-TLR occurred in seven (9.2%) and six (14.6%) patients with CFA and popliteal artery lesions, respectively, whereas clinical success was achieved in 62 (91.2%) and 31 (75.6%), respectively. Patients treated with atherectomy and DCB in the popliteal artery after matching for baseline RC, lesion calcification, length, and the presence of chronic total occlusion, exhibited higher freedom from CD-TLR compared to the nondebulking group (HR = 3.1; 95% CI = 1.1-8.5, p = 0.03). Conclusion: Atherectomy can be used safely and is associated with low rates of bail-out stenting in CFA and popliteal arteries. CD-TLR and clinical success rates are clinically acceptable. In addition, for the popliteal artery, atherectomy combined with DCB demonstrates lower CD-TLR rates compared to a DCB alone strategy. (German Clinical Trials Register: DRKS00016708).

Novel Therapeutic Concepts for Complex Femoropopliteal Lesions Using the Jetstream Atherectomy System.

INTRODUCTION: The presence of severe arterial calcification is associated with less favorable outcomes in terms of procedural and clinical success as well as higher rates of major adverse limb events. Recent studies incorporating rotational atherectomy for effective preparation of severely calcified lesions demonstrate beneficial procedural outcomes by obtaining maximal luminal gain and improved long-term outcomes. METHODS: This prospective single-center, observational study includes patients with severely calcified femoropopliteal lesions with chronic limb ischemia Rutherford 1-5 between January 2017 and July 2019, who underwent atherectomy using the Jetstream Atherectomy system, followed by drug-coated balloon angioplasty. Lesion calcification was categorized by the Peripheral Arterial Calcium Scoring System (PACSS), whereas lesion complexity was classified by the Transatlantic Inter-Society Consensus (TASC). Safety and efficacy aspects in terms of vessel injury, thromboembolism, and clinical success were systematically analyzed up to 12 months of follow-up (FU). RESULTS: In 162 consecutive patients, 210 non-stented and 22 stented lesions were treated. Twelve (7.4%) patients received bail-out stenting. Mean lesion length was 24.2±4.8 cm; 51% were chronic total occlusions (mean occlusion length 18.2±5.1 cm). TASC C lesions were present in 38 patients (23.5%) and TASC D lesions in 124 patients (76.5%). The mean PACCS score was 3.3±0.9. Device success was achieved in 88%; procedural success was noted in 99% of the lesions. Embolic protection device was used in 11.7%. Perforation or dissection occurred in none of the cases. Asymptomatic peripheral embolization was noted in 10 patients (6.2%). Clinical FU at 12 months was available in 157 of 162 patients (96.9%). At 12 month FU, (1) mean Rutherford classification at baseline of 3.7±0.6 significantly dropped to 1.0±0.9 (p<0.05), (2) baseline mean anke-brachial index (ABI) of 0.4±0.1 significantly increased to 0.8±0.2 (p<0.05), (3) 92.6% were free from target lesion revascularization (TLR), (4) 95.1% were free from target vessel revascularization (TVR), and (5) binary restenosis measured by duplex occurred in 22 patients (13.6%). Multivariate analyses showed lesion length as predictive of stent placement (p=0.02), whereas both lesion length (p=0.006) and PACCS score (p=0.02) are predictive of clinical success. CONCLUSION: Rotational atherectomy in combination with drug-coated balloon (DCB) can be safely performed in long, calcified (non-) occlusive lesions with a relatively low rate of bail-out stenting and favorable clinical mid-term results. CLINICAL IMPACT: In this prospective, single arm study we demonstrated that combination treatment using rotational atherectomy and DCB is safe and effective in complex and calcified TASC C/D femoropopliteal lesions in patients with claudication or CLTI in a real-world clinical setting. Despite mean lesion length of >20cm and a relatively high rate of chronic total occlusions, the rate of bail-out stenting was surprisingly low (7.4%), whereas the rates of freedom from TLR and TVR were surprisingly high. Thus, our study may encourage vascular specialists to choose an endovascular -first approach even in such complex and calcified femoropopliteal lesions and occlusions in daily clinical practice.

Phoenix atherectomy for patients with peripheral artery disease.

BACKGROUND: Endovascular atherectomy enables minimally invasive plaque removal in peripheral artery disease (PAD). AIMS: We aimed to evaluate the safety and the long-term effectiveness of the Phoenix atherectomy for the treatment of complex and calcified lesions in PAD patients. METHODS: Consecutive all-comer patients with PAD underwent the Phoenix atherectomy. Device safety in terms of perforation and distal embolisation were evaluated. Lesion calcifications were categorised by the Peripheral Arterial Calcium Scoring System (PACSS) and lesion complexity was assessed by the Transatlantic Inter-Society Consensus (TASC). Clinically driven target lesion revascularisation (TLR) was assessed. RESULTS: A total of 558 lesions were treated in 402 consecutive patients. Clinical follow-up was available at 15.7±10.2 months for 365 (91%) patients. Of 402 patients, 135 (33.6%) had claudication, 37 (9.2%) had ischaemic rest pain and 230 (57%) exhibited ischaemic ulcerations. Lesions were mostly identified in the femoropopliteal segments (55%), followed by below-the-knee (BTK) segments (32%). Complex TASC C/D lesions and moderate to severe calcifications (PACSS score ≥2) were present in 331 (82%) and 323 (80%) patients, respectively. The mean lesion length was 20.6±14.3 cm. Five (1%) perforations and 10 (2%) asymptomatic embolisations occurred. Bail-out stenting was performed in 4%, 16% and 3% of patients with common femoral artery, femoropopliteal and BTK lesions, respectively. During follow-up, 5 (3.9%) patients with claudication and 52 (21.9%) patients with critical limb-threatening ischaemia (CLTI) died (hazard ratio [HR] 3.7; p<0.001). Freedom from TLR was 87.5% (112 of 128) in patients with claudication and 82.3% (195 of 237) in patients with CLTI, respectively (HR 1.8; p=0.03). CONCLUSIONS: The Phoenix atherectomy can be safely performed in patients with complex lesions with a relatively low rate of bail-out stenting and clinically acceptable TLR rates. GERMAN CLINICAL TRIALS REGISTER: DRKS00016708.

Orbital Atherectomy Prior to Drug-Coated Balloon Angioplasty in Calcified Infrapopliteal Lesions: A Randomized, Multicenter Pilot Study.

PURPOSE: Optimal balloon angioplasty for infrapopliteal lesions is often limited by severe calcification, which has been associated with decreased procedural success and lower long-term patency. MATERIALS AND METHODS: This was a prospective, randomized, multicenter pilot trial that included adult subjects with calcified lesions located from the popliteal segment below the knee (BTK) joint to within 5 cm above the ankle with ≥70% diameter stenosis by angiography. Patients were randomized 1:1 to undergo orbital atherectomy (OA) with adjunctive drug-coated balloon (DCB) angioplasty versus plain balloon angioplasty (BA) and DCB angioplasty (control). The periprocedural and 12 month outcomes of both procedures were compared. RESULTS: Overall, 66 subjects (OA + DCB = 32 vs control = 34) were included in an intention to treat analysis. Baseline demographics and lesion characteristics were well-balanced. The mean lesion length was 101.3 mm (SD = 72.8 mm) and 78.8 (SD = 61.0 mm) in the OA + DCB and control groups, respectively, with almost all lesions having severe calcification per the Peripheral Academic Research Consortium (PARC) criteria. Chronic total occlusions (CTOs) were present in 43.8% and 35.3% of the patients in the OA + DCB and control groups, respectively. The technical success of OA + DCB versus DCB was 81.8% and 89.2%, respectively, with 3 slow flow/no reflow, 1 perforation, 1 severe dissection occurred in OA + DCB group, and one distal embolization occurred in the control group. The target lesion primary patency rate was numerically higher in the OA + DCB versus control group at 6 (88.2% vs 50.0%, p=0.065) and 12 month follow-up (88.2% vs 54.5%, p=0.076). The 12 month freedom from major adverse events, clinically-driven target lesion revascularization, major amputation, and all-cause mortality rates were similar between both groups. CONCLUSION: The results of the Orbital Vessel PreparaTIon to MaximIZe Dcb Efficacy in Calcified BTK (OPTIMIZE BTK) pilot study indicated that utilization of OA + DCB is safe for infrapopliteal disease. Further prospective adequately powered studies should investigate the potential benefit of combined OA + DCB for BTK lesions.

Safety, effectiveness and mid-term follow-up in 136 consecutive patients with moderate to severely calcified lesions undergoing phoenix atherectomy.

To investigate the safety and effectiveness of the Phoenix atherectomy device for the treatment of complex and calcified lesions in patients with peripheral artery disease (PAD). 136 consecutive all-comer patients with chronic PAD underwent Phoenix atherectomy. Safety in terms of vessel injury and embolism, efficacy and clinical success in terms of ≥ 1Rutherford class (RF) improvement during follow-up were systematically analyzed. Lesion calcification was categorized by the Peripheral Arterial Calcium Scoring System (PACSS), whereas lesion complexity was classified by the Transatlantic Inter-Society Consensus (TASC). 151 lesions were treated in 136 consecutive patients. Clinical follow-up was available at 10.3 ± 4.2 months in 132 (97%) patients. 55 patients (40%) had intermittent claudication, 16 (12%) rest pain and 65 (48%) had ischemic ulcerations (mean RF class = 4.2 ± 1.1). 15 (11%) patients had TASC B lesions, whereas the majority 72 (53%) and 49 (36%) exhibited TASC C and D lesions, respectively. Mean PACSS score was 3.3 ± 0.9. Mean lesion length was 106 ± 92 mm. Atherectomy was combined with drug-coated balloon (DCB) in 129 (95%) patients. Nine (6.6%) patients with infra-inguinal lesions received stents. Technical and procedural success were recorded in 102 (75%) and 135 (99%), respectively. Perforation was noticed in 2 (1%), whereas asymptomatic embolism occurred in 6 (4%) patients. Clinical success was present in 54 (100%) patients with claudication and in 65 of 78 (83%) patients with critical limb ischemia (CLI). Atherectomy in combination with DCB angioplasty can be safely performed in patients with complex, calcified peripheral lesions with a relatively low rate of bail-out stenting and promising clinical mid-term results.German Clinical Trials Register: DRKS00016708.

The evolving role of drug-coated balloons for the treatment of complex femoropopliteal lesions.

Conventional therapies for transcatheter treatment of patients with infrainguinal obstructive disease remain compromised by high restenosis rates. Drug-coated balloons (DCB) offer a novel therapeutic alternative targeting the source of neo-intimal hyperplasia, without the need for a permanent endovascular scaffold and their inherent limitations. A systematic research of the medical databases (Pubmed) has been conducted for this up-to-date review. Key words, such as "drug-coated balloons" (DCB), "drug-eluting balloon," "in-stent-restenosis" (ISR), "de-novo stenosis," "plain old angioplasty," "atherectomy," "debulking," "superficial femoral artery," "popliteal artery," "above/below the knee," and "peripheral artery disease" have been used for literature search. Furthermore, data from reviews, original contributions, randomized controlled studies, observational studies, registries and single center experiences have been considered. Overall, an increasing level of evidence supports the use of DCB for the treatment of long, complex, heavily calcified femoropopliteal non-occlusive and occlusive lesions, including failure after BM stent implantation due to ISR. However, more studies will be necessary to investigate the long-term effects of DCB-treatment in these real-world lesions.

Short and long-term results after endovascular management of vascular complications during transfemoral aortic valve implantation.

Background Vascular injury and access site complications in the contemporary setting of transcatheter aortic valve implantation (TAVI) are known to be associated with increased mortality and morbidity. The aim of our study was to analyse the feasibility and safety of percutaneous treatment of such vascular complications using a stent graft. Methods Between January 2010 and April 2013, 36 TAVI patients developed severe access site complications and underwent subsequent interventional treatment with a covered stent. Acute treatment success was confirmed by angiography immediately after the implantation of the stent graft, with clinical long-term patency follow-up being assessed by duplex ultrasound. Results Of the 36 patients evaluated, percutaneous treatment of the acute access site bleeding was successful in 35 patients (97%), with one patient requiring surgical intervention due to insufficient haemostasis after stent graft implantation. A subset of 5 patients underwent successful ipsilateral stent graft implantation, either because crossover sheath placement was not feasible (n = 1), or intentionally with an even sheathless approach in an effort to reduce vessel injury (n = 4). After a mean follow-up of 22 ± 8 months, stent graft patency was confirmed by duplex ultrasound in 13 patients with an additional 5 patients reporting to be free from symptoms and claudication. Thirteen patients died within the first 24 months after the procedure, however, none was due to access vessel complications. Five patients were lost for follow-up. Conclusions Our data confirm that endovascular treatment of access site complications related to TAVI is feasible, safe and efficacious, resulting in long-term vascular patency.

The role of drug-coated balloons in in-stent restenosis.

Despite a constantly expanding spectrum of therapeutic options for lower limb artery disease, there is not yet a well-defined consensus on the specific type of endovascular treatment that is best suited. Clinical data on patients with femoropopliteal disease treated with drug-coated balloons have not been elaborated sufficiently, especially in the case of in-stent restenosis. For this review a systematic research of the medical databases (Pubmed) has been conducted. Keywords such as "drug-coated balloons" (DCB), "drug-eluting balloons," "in-stent restenosis", "de novo stenosis", "angioplasty", "superficial femoral artery," "popliteal artery," "above the knee," "below the knee," "peripheral artery disease" (PAD) have been used. Furthermore, data from reviews, original contributions regarding randomized controlled studies, observational studies, registries and single center experiences have been included. Many trials have shown superiority for DCB- over percutaneous transluminal angioplasty-treatment alone in TASC IIA and TASC IIB femoropopliteal lesions. However, the currently available DCB systems are different in terms of efficacy and long-term outcomes depending on their mechanical and pharmacological features. Moreover, angiographic characteristics of femoropopliteal lesions classified by Tosaka seem to influence subsequent outcomes of DCB treatment. Lastly, there is still lack of reliable prospective long-term data regarding DCB technology.

Multiparametric Functional MRI: A Tool to Uncover Subtle Changes following Allogeneic Renal Transplantation.

PURPOSE: To investigate multiparametric functional MRI to characterize acute rejection in a murine allogeneic renal transplant model and evaluate the effect of novel therapeutics. MATERIAL AND METHODS: We performed allogeneic and syngeneic orthotopic transplantations (Balb/c to C57Bl/6 and C57Bl/6 to C57Bl/6). Allogeneic Groups (n = 5) were either treated with the anti-CCL2-Spiegelmer (mNOX-E36) in monotherapy or in combination with low doses of Ciclosporin-A (10mg/kgBW/d) for 10 days. Controls received equivalent doses of a non-functional spiegelmer (revmNOX-E36) or low dose Ciclosporin-A. Diffusion-weighted (DWI) and Dynamic-contrast-enhanced (DCE-) MRI-scans were performed using a clinical 3T-scanner. DWI analysis (b-values from 0-800 s/mm2) was performed mono- and biexponentially, while DCE-MRI was assessed with deconvolution analysis. Therapy effects were assessed ex vivo with histopathology, immunohistochemistry and RT-PCR. Statistical analysis was performed with unpaired t-tests and Spearman´s correlation coefficient. RESULTS: DWI showed a significant diffusion restriction in allogeneic compared to syngeneic transplants (ADC: 0.63±0.08 vs. 1.29±0.12 mm2/s*103) with decreasing diffusion restriction under therapy. DCE-MRI showed restored organ perfusion under Ciclosporin A alone and combination therapy (Plasma Flow: 43.43±12.49; 38.75±7.53ml/100ml/min) compared to syngeneic controls (51.03±12.49ml/100ml/min). Ex vivo analysis showed reduced monocytic infiltrates, attenuated levels of inflammatory cytokines under mNOX-E36 monotherapy with an additive effect of low dose Ciclosporin A. There was a significant (p<0.05) negative correlation between ADC and interstitial inflammation (r = -0.73) or macrophage infiltration (r = -0.81) and between organ perfusion and intimal arteritis (r = -0.63). CONCLUSION: Multiparametric functional MRI is suited to detect renal allograft rejection in an experimental murine model and allows to characterize effects of immunosuppressive therapy alleviating acute rejection processes in allogeneic transplantation.

Inhibition of Cardiac Kir Current (IK1) by Protein Kinase C Critically Depends on PKCß and Kir2.2.

BACKGROUND: Cardiac inwardly rectifying Kir current (IK1) mediates terminal repolarisation and is critical for the stabilization of the diastolic membrane potential. Its predominant molecular basis in mammalian ventricle is heterotetrameric assembly of Kir2.1 and Kir2.2 channel subunits. It has been shown that PKC inhibition of IK1 promotes focal ventricular ectopy. However, the underlying molecular mechanism has not been fully elucidated to date. METHODS AND RESULTS: In the Xenopus oocyte expression system, we observed a pronounced PKC-induced inhibition of Kir2.2 but not Kir2.1 currents. The PKC regulation of Kir2.2 could be reproduced by an activator of conventional PKC isoforms and antagonized by pharmacological inhibition of PKCß. In isolated ventricular cardiomyocytes (rat, mouse), pharmacological activation of conventional PKC isoforms induced a pronounced inhibition of IK1. The PKC effect in rat ventricular cardiomyocytes was markedly attenuated following co-application of a small molecule inhibitor of PKCß. Underlining the critical role of PKCß, the PKC-induced inhibition of IK1 was absent in homozygous PKCß knockout-mice. After heterologous expression of Kir2.1-Kir2.2 concatemers in Xenopus oocytes, heteromeric Kir2.1/Kir2.2 currents were also inhibited following activation of PKC. CONCLUSION: We conclude that inhibition of cardiac IK1 by PKC critically depends on the PKCß isoform and Kir2.2 subunits. This regulation represents a potential novel target for the antiarrhythmic therapy of focal ventricular arrhythmias.

Critical role of RAGE and HMGB1 in inflammatory heart disease.

Autoimmune response to cardiac troponin I (TnI) induces inflammation and fibrosis in the myocardium. High-mobility group box 1 (HMGB1) is a multifunctional protein that exerts proinflammatory activity by mainly binding to receptor for advanced glycation end products (RAGE). The involvement of the HMGB1-RAGE axis in the pathogenesis of inflammatory cardiomyopathy is yet not fully understood. Using the well-established model of TnI-induced experimental autoimmune myocarditis (EAM), we demonstrated that both local and systemic HMGB1 protein expression was elevated in wild-type (wt) mice after TnI immunization. Additionally, pharmacological inhibition of HMGB1 using glycyrrhizin or anti-HMGB1 antibody reduced inflammation in hearts of TnI-immunized wt mice. Furthermore, RAGE knockout (RAGE-ko) mice immunized with TnI showed no structural or physiological signs of cardiac impairment. Moreover, cardiac overexpression of HMGB1 using adeno-associated virus (AAV) vectors induced inflammation in the hearts of both wt and RAGE-ko mice. Finally, patients with myocarditis displayed increased local and systemic HMGB1 and soluble RAGE (sRAGE) expression. Together, our study highlights that HMGB1 and its main receptor, RAGE, appear to be crucial factors in the pathogenesis of TnI-induced EAM, because inhibition of HMGB1 and ablation of RAGE suppressed inflammation in the heart. Moreover, the proinflammatory effect of HMGB1 is not necessarily dependent on RAGE only. Other receptors of HMGB1 such as Toll-like receptors (TLRs) may also be involved in disease pathogenesis. These findings could be confirmed by the clinical relevance of HMGB1 and sRAGE. Therefore, blockage of one of these molecules might represent a novel therapeutic strategy in the treatment of autoimmune myocarditis and inflammatory cardiomyopathy.

SDF-1/CXCR4/CXCR7 is pivotal for vascular smooth muscle cell proliferation and chronic allograft vasculopathy.

Chronic rejection remains a major obstacle in transplant medicine. Recent studies suggest a crucial role of the chemokine SDF-1 on neointima formation after injury. Here, we investigate the potential therapeutic effect of inhibiting the SDF-1/CXCR4/CXCR7 axis with an anti-SDF-1 Spiegelmer (NOX-A12) on the development of chronic allograft vasculopathy. Heterotopic heart transplants from H-2bm12 to B6 mice and aortic transplants from Balb/c to B6 were performed. Mice were treated with NOX-A12. Control animals received a nonfunctional Spiegelmer (revNOX-A12). Samples were retrieved at different time points and analysed by histology, RT-PCR and proliferation assay. Blockade of SDF-1 caused a significant decrease in neointima formation as measured by intima/media ratio (1.0 ± 0.1 vs. 1.8 ± 0.1, P < 0.001 AoTx; 0.35 ± 0.05 vs. 1.13 ± 0.27, P < 0.05 HTx). In vitro treatment of primary vascular smooth muscle cells with NOX-A12 showed a significant reduction in proliferation (0.42 ± 0.04 vs. 0.24 ± 0.03, P < 0.05). TGF-ß, TNF-α and IL-6 levels were significantly reduced under SDF-1 inhibition (3.42 ± 0.37 vs. 1.67 ± 0.33, P < 0.05; 2.18 ± 0.37 vs. 1.0 ± 0.39, P < 0.05; 2.18 ± 0.26 vs. 1.6 ± 0.1, P < 0.05). SDF-1/CXCR4/CXCR7 plays a critical role in the development of chronic allograft vasculopathy (CAV). Therefore, pharmacological inhibition of SDF-1 with NOX-A12 may represent a therapeutic option to ameliorate chronic rejection changes.

Renal sympathetic denervation therapy in the real world: results from the Heidelberg registry.

INTRODUCTION: Renal sympathetic denervation (RDN) is a novel treatment option in patients with treatment-resistant arterial hypertension. A subset of recently published randomized and non-randomized trials indicates that RDN leads to sustained lowering of blood pressure (BP) under controlled study conditions. However, registry data that allow evaluation of safety and efficacy in a real-world setting are largely missing. METHODS: Sixty-three consecutive patients with treatment-resistant hypertension underwent RDN with the radiofrequency-based Symplicity™ catheter. As part of our prospective registry, treatment efficacy and safety were monitored after 3, 6, and 12 months. RESULTS: At 6 months follow-up, office systolic BP significantly improved by 19 + 23 mmHg as compared to baseline, while diastolic BP values reduced by 6 + 13 mmHg (p < 0.05). One year after RDN, office BP levels further improved (26 + 25 mmHg in systolic BP and 9 + 13 mmHg in diastolic BP, respectively), even though 19 patients had reduced the number and/or dosage of antihypertensive agents. The response rate, defined as reduction of office systolic BP of ≥ 10 mmHg, was 73% after 6 months. Baseline BP was the only significant predictor of blood pressure response, whereas no correlation was found between the number of ablation points and the individual changes in office blood pressure. Interestingly, patients with challenging renal anatomy profited somewhat less from the procedure than those with "normal" renal anatomy. Procedure related adverse events occurred in three patients (4.7%) and were limited to vascular access complications. CONCLUSIONS: RDN with the Symplicity™ system is safe and effective in patients with treatment-resistant hypertension also in a real-world setting.

Mucosal tolerance induction in autoimmune myocarditis and myocardial infarction.

BACKGROUND: Antigen-specific therapy is a compelling approach for the treatment of autoimmune conditions. Primary goal is to induce the specific tolerization of self-reactive immune cells without altering host immunity against pathogens. We studied the effects of mucosal tolerance induction on cTnI-induced experimental autoimmune myocarditis (EAM) and post-infarct remodeling. METHODS: Mucosal tolerance was induced by intranasal application of cTnI, alternatively anti-CD3 p.o. Protocols varied in frequency, dosage and time point of application before EAM. We then applied the most effective regimen to mice undergoing myocardial infarction in order to verify its effectiveness in post-infarct cardiac remodeling. The myocardium was evaluated on histological slides and for the cytokine secretion pattern, while echocardiography determined cardiac function. RESULTS: A single dose of 100 µg of cTnI 7 days prior to myocarditis appeared to be most effective in suppressing inflammation and fibrosis (p = 0.03), while improving fractional shortening (p = 0.02). Treatment with intranasal cTnI upregulated IL-10 expression. On the other hand, frequent intranasal application of high doses of cTnI increased myocardial inflammation. Anti-CD3 p.o. showed the propensity to reduce myocardial inflammation and improve cardiac function. The single dose regimen of i.n. cTnI applied 7 days before a myocardial infarction reduced inflammation by trend (p=0.07) and improved heart function (p=0.002). Moreover, expression of matrix metalloproteinases 9 and 14 significantly decreased when treated with intranasal cTnI (p<0.01). CONCLUSIONS: Depending on the optimal amount, the time period and the choice of antigen, effective mucosal tolerance can be achieved and represents an appealing therapeutic approach in the inflammatory process of cardiac remodeling.

Short-term akt activation in cardiac muscle cells improves contractile function in failing hearts.

Akt is a serine/threonine protein kinase that is activated by a variety of growth factors or cytokines in a phosphatidylinositol 3-kinase-dependent manner. By using a conditional transgenic system in which Akt signaling can be turned on or off in the adult heart, we previously showed that short-term Akt activation induces a physiological form of cardiac hypertrophy with enhanced coronary angiogenesis and maintained contractility. Here we tested the hypothesis that induction of physiological hypertrophy by short-term Akt activation might improve contractile function in failing hearts. When Akt signaling transiently was activated in murine hearts with impaired contractility, induced by pressure overload or doxorubicin treatment, contractile dysfunction was attenuated in both cases. Importantly, improvement of contractility was observed before the development of cardiac hypertrophy, indicating that Akt activation improves contractile function independently of its growth-promoting effects. To gain mechanistic insights into Akt-mediated positive inotropic effects, transcriptional profiles in the heart were determined in a pressure overload-induced heart failure model. Biological network analysis of differentially expressed transcripts revealed significant alterations in the expression of genes associated with cell death, and these alterations were reversed by short-term Akt activation. Thus, short-term Akt activation improves contractile function in failing hearts. This beneficial effect of Akt on contractility is hypertrophy-independent and may be mediated in part by inhibition of cell death associated with heart failure.