Performance of implantable loop recorders. Role of R vector and detection algorithms.

INTRODUCTION: We evaluated the performance of implantable loop recorders (ILRs) with different detection algorithms and looked for artifacts and therapeutic consequences and their dependence on patient factors. METHODS AND RESULTS: 586 RevealLinq™ ILRs (first generation (NT): n = 335; second generation with TruRhythm™ (TR): n = 251) were implanted during 2014-2021 (syncope n = 206; embolic stroke of unknown source (ESUS) n = 380). Automatically detected EGM episodes (n = 18,650) were classified as correct or incorrect for asystole (AS), atrial fibrillation (AF) or tachycardia (TA). Incorrect episodes were caused by loss of signal (LO), noise (NO), extrasystole (ES) and T-wave oversensing (TWO). Left directed R axes, lower R-amplitudes and older age were related to artifacts. Results were separated by indication. In ESUS patients TR reduced total median artifact episodes: 0.6 (0-7) vs 0 (0-5) (p < 0.03) and median artifact examination time: 0.3 (0-3.5) vs 0 (0-2.5) (p = 0.03) per patient-year. This benefit is caused by significant reductions in total AS and ES-AS artifacts. The total positive predictive value (PPV) improved only in syncope patients (45 vs 71%, p = 0.002). Accordingly in syncope patients with TR more therapeutic consequences could be established (log rank 0.003). DISCUSSION: Patients R-axis and measured R-amplitudes during implantation predicted artifacts. This should be taken into account during ILR implantation. Total artifacts, AS artifacts and time spent for artifact analysis was reduced by the new TR detection algorithm in ESUS patients, whereas total artifacts remained unchanged in syncope patients despite reduction of AS artifacts. However TR had no effect on AF and TA episode detection and therefore has to be improved.

Tricuspid regurgitation is a predictor of mortality after percutaneous mitral valve edge-to-edge repair.

AIMS: The aim of this study was to determine the impact of tricuspid regurgitation (TR) on mortality after edge-to-edge percutaneous mitral valve repair (PMVR), and also to analyse whether there is a difference in outcome between patients with improvement of TR after PMVR compared to patients without. METHODS AND RESULTS: Out of 197 consecutive patients who underwent PMVR, 139 patients with available follow-up (mean 428±386 days) were included in the study. Concomitant moderate/severe TR was present in 58.3% of patients. Kaplan-Meier analysis showed significantly reduced overall survival for patients with moderate/severe TR, compared to patients with none/mild TR (p=0.003). Cox multivariate regression analysis revealed severe TR at baseline as the strongest independent predictor of mortality (HR 4.367, p=0.003). An improvement of the baseline moderate/severe TR was observed in 45.5% of patients at 30-day follow-up. Patients with no improvement of TR after PMVR had a higher midterm mortality compared to patients in whom TR improved (40.5% versus 11.4%, p=0.005). CONCLUSIONS: More than half of patients undergoing PMVR have concomitant moderate/severe TR, which is associated with a worse outcome. Among predictors of mortality after edge-to-edge PMVR, severe TR at baseline is the most important. Patients with no improvement of TR at 30 days after PMVR have a significantly higher mortality at follow-up.

Increased Risk of Cerebral Embolization After Implantation of a Balloon-Expandable Aortic Valve Without Prior Balloon Valvuloplasty.

OBJECTIVES: The purpose of this study was to analyze the effect of transcatheter aortic valve replacement (TAVR) without versus with prior balloon aortic valvuloplasty (BAV) on the risk of cerebral embolization in patients who receive a balloon-expandable valve. BACKGROUND: Avoiding BAV prior to TAVR may simplify the procedure, but the risk of cerebral embolization is currently unknown. METHODS: A total of 87 consecutive high surgical-risk patients with no contraindications for diffusion-weighted magnetic resonance imaging (DW-MRI) were enrolled. Thirty-two patients received a balloon-expandable aortic valve with and 55 patients without BAV. The incidence, number, and volume of new ischemic lesions in DW-MRI performed 2 to 7 days after TAVI were evaluated. RESULTS: Mean age (83.8 ± 5.2 years vs. 82.9 ± 6.8 years) and sex (43.8% vs. 52.7% male) of the patients with versus without BAV, respectively, as well as other demographic and hemodynamic data were not significantly different between both groups. The procedural success rate was 93.5% with and 98.2% without BAV, and procedure duration and contrast volume were significantly lower without BAV. The incidence of new cerebral ischemic lesions in the total cohort was 66.7%. Compared with patients with BAV, those without BAV had a significantly higher total volume of cerebral ischemic lesions (235.4 ± 331.4 mm(3) vs. 89.5 ± 128.2 mm(3); p = 0.01). CONCLUSIONS: The implantation of a balloon-expandable aortic valve without versus with prior BAV, although performed with a shorter procedure time and lower contrast volume, is associated with a significantly higher volume of cerebral ischemic lesions.

Percutaneous, transendocardial injection of bone marrow-derived mononuclear cells in heart failure patients following acute ST-elevation myocardial infarction: ALSTER-Stem Cell trial.

AIMS: Patients with symptomatic heart failure following acute ST-elevation myocardial infarction (STEMI) received transendocardial application of bone marrow-derived mononuclear cells (BMC) to improve left ventricular (LV) function and clinical outcome. METHODS AND RESULTS: Patients (n=12) with LV ejection fraction (EF) <45% and NYHA Class ≥II received NOGA-guided transendocardial injection of BMC into the infarction border zone 17.5±0.8 days following successful interventional revascularisation after STEMI. A matched control group (n=11) was generated from the source data of the previously published LIPSIAbciximab-STEMI trial. Primary and secondary endpoints were derived from comparisons of baseline vs. six-month follow-up cardiac magnetic resonance imaging (CMR) measurements and clinical assessments. Following cell therapy we observed a significant increase of EF (+7.9±1.5%, p=0.001) while the control group showed no change. This effect was driven by a reduction of LV end-systolic volume (ESV) by -27.5±6.5 ml (p=0.001); LV end-diastolic volume (EDV) and scar volu-me remained unchanged. A significant decrease of NYHA Class was found only in the cell therapy group (-0.75 vs. -0.18, p=0.04). Findings were also translated into enhancement of clinical assessments (rehospitalisation for decompensated heart failure, six-minute walk test, NT-proBNP levels). CONCLUSION: The data suggest transendocardial injection of BMC can be used safely in patients with sympto-matic heart failure following acute STEMI. These prospective, preliminary data of a well-characterised, small cohort suggest efficiency compared to routine treatment.

Ablation surgery in patients with persistent atrial fibrillation: an 8-year clinical experience.

OBJECTIVE: This analysis was undertaken to evaluate the results of persistent atrial fibrillation ablation procedures concomitant to open surgery and to identify risk factors for persistent atrial fibrillation recurrence. METHODS: Since 2001, a total of 325 consecutive patients with persistent atrial fibrillation (duration, 0.5-33 years) have undergone persistent atrial fibrillation ablation concomitant to open surgery by creating 2 encircling isolation lesions around the left and right pulmonary veins and a connecting lesion between both with the use of radiofrequency ablation procedures. Patients were restudied at discharge, 3 months, and 3 years after surgery. RESULTS: Survivals at the time of reexamination at discharge, 3 months, and 3 years were 97.8%, 96.2%, and 94.4%, respectively. Stable sinus rhythm could be documented in 72.1%, 73.9%, and 75.6% of surviving patients, respectively. Long-term persistent atrial fibrillation before surgery and a larger left atrium were predictive of postoperative persistent atrial fibrillation return (P<.001). Statistical analysis demonstrated cutoff points of 5 years for persistent atrial fibrillation and 55 mm for left atrium diameter; 89.7% of patients with persistent atrial fibrillation duration of less than 5 years and 84.5% of patients with left atrium size of 55 mm or less were in stable sinus rhythm at late follow-up. Cardiac rhythm at discharge and at 3 months was predictive of long-term rhythm prognosis (P<.001). Age, gender, concomitant diseases (eg, arterial hypertension, diabetes, renal insufficiency, or pulmonary disease), and the underlying cause of heart disease did not significantly influence the postoperative cardiac rhythm. CONCLUSIONS: The duration of persistent atrial fibrillation and the size of the left atrium are the most reliable preoperative variables to predict the success rate of ablation concomitant to open surgery. The probability of reestablishing stable sinus rhythm is excellent when persistent atrial fibrillation duration is short and left atrium size is small.

Stem cell therapy in cardiovascular disorders.

Heart insufficiency remains the leading cause of death despite pharmacological and interventional therapy as well as primary and secondary prevention. Laboratory research on cardiac repair implementing stem cells and progenitor cells has raised great expectations as well as controversies. The potential of diverse progenitor cells to repair damaged heart tissue includes replacement (tissue transplant), restoration (activation of resident cardiac progenitor cells, paracrine effects), and regeneration (stem cell engraftment forming new myocytes). Based on promising experimental results clinical trials including several hundreds of patients with ischemic heart disease have been initiated using mostly bone marrow-derived cells. Probably, due to a lack of standardization of cell isolation and delivery methods these trials showed controverse results regarding effectiveness. However, significant therapeutic regeneration of human myocardium could not be proven until now. Several issues are at debate concerning the translation of the experimental data into the clinic discussing the adequate cell type, dosing, timing, and delivery mode of myocardial stem cell therapy. This review focuses on the potential and clinical translation of cell based therapies in cardiovascular disease.

Regional diastolic and systolic function by strain rate imaging for the detection of intramural viability during dobutamine stress echocardiography in a porcine model of myocardial infarction.

The aim of this study was to evaluate diastolic and systolic strain rate measurements for differentiation of transmural/nontransmural infarction during dobutamine stress echocardiography (DSE). An ameroid constrictor was placed around the circumflex artery in 23 pigs inducing chronic vessel occlusion. Five pigs without constrictor served as controls. During high-dose DSE systolic strain rates (SR(sys)), systolic and postsystolic strain values (epsilon(sys), epsilon(ps)) and early and late diastolic strain rates (SR(E) and SR(A)) were determined. At week 6, animals were evaluated regarding myocardial fibrosis. Histology revealed nontransmural in 14 and transmural infarction in 9 animals. In controls, dobutamine induced a linear increase of SR(sys) to 12.3 + or - 0.4 s(-1) at 40 microg/kg per minute (P = 0.001) and a linear decrease of SR(E) to -6.6 + or - 0.3 s(-1) (P = 0.001). In the nontransmural group, SR(sys), epsilon(sys), epsilon(ps) at rest, and during DSE were higher and SR(E) was lower than in the transmural infarction group (P = 0.01). Best predictors for viability were SR(sys) (ROC 0.96, P = 0.0003), SR(E) at 10 microg/kg per minute dobutamine stimulation (ROC 0.94, P = 0.001) and positive SR values during isovolumetric relaxation at 40 microg/kg per minute dobutamine (ROC 0.86, P = 0.004). The extension of fibrosis correlated with SR(sys) at rest, epsilon(sys) at rest, and SR(E) at rest (P < 0.001). For the detection of viability similar diagnostic accuracies of SR(E) and SRsys were seen (sensitivity 93%/93%, specificity 96%/94%, respectively). Diastolic SR analysis seems to be equipotent for the identification of viable myocardium in comparison to systolic SR parameters and allows the differentiation of nontransmural from transmural myocardial infarction with high diagnostic accuracy. (Echocardiography 2010;27:552-562).

Limited immune-modulating activity of porcine mesenchymal stromal cells abolishes their protective efficacy in acute kidney injury.

We demonstrated previously that administration of mesenchymal stromal cells (MSCs) after renal ischemia/reperfusion injury (IRI) in rats protected renal function and hastened repair through complex paracrine mechanisms. Here we investigated kidney-protective actions of MSCs in a porcine IRI model that may have relevance to human acute kidney injury (AKI). Groups of female pigs with bilateral IRI were infused with autologous or male allogeneic MSCs. No acute or late complications were observed, but unexpectedly, MSC therapy also had no beneficial effects on kidney function and histology. In vitro, we demonstrated substantial functional and phenotypic overlaps between rodent, human, and porcine MSCs, all of which exhibited trilineage differentiation, characteristic antigen profiles, and secretion of renoprotective vascular endothelial growth factor (VEGF)-A and insulin-like growth factor-1 (IGF-1). However, in striking contrast to human MSCs, porcine MSCs failed to inhibit the mixed lymphocyte reaction (MLR) and induced robust production of proinflammatory interleukin-6 (IL-6). In summary, in contrast to rodent models, treatment of porcine IRI with MSCs was not kidney-protective. This, we conclude, is due to the fact that porcine MSCs exert inadequate immune-modulating effects, further demonstrating that successful therapy of IRI with MSCs critically depends on their anti-inflammatory actions. As a consequence, treatment of AKI with MSCs is not informative regarding the investigation of the underlying mechanisms in this large animal model. We expect, however, that the treatment of human IRI of the kidney with immune-modulating MSCs will be as effective as in rodent models.

Slow wall motion rather than electrical conduction delay underlies mechanical dyssynchrony in postinfarction patients with narrow QRS complex.

INTRODUCTION: The mechanism of mechanical dyssynchrony in postinfarction patients with a narrow QRS complex is not defined but essential for cardiac resynchronization therapy (CRT). METHODS AND RESULTS: Left ventricular electrical activation and subsequent wall motion were recorded for 16 patients with ischemic cardiomyopathy during intrinsic rhythm using a modified NOGA electromechanical mapping system. Ten patients presented mechanical dyssynchrony on tissue Doppler imaging, while 6 patients served as control subjects. The local activation time (LAT) was set by the maximum downslope of the unipolar electrogram. Local wall motion time (LMT) was defined as the time needed for the catheter tip to traverse half of its maximum inward deflection during systole. LAT and LMT were measured relative to the onset of the QRS complex. Electrical activation showed a septal-to-lateral pattern in all patients with a mean endocardial activation time of 65 +/- 13 ms. Control subjects exhibited 97.5% of all LMTs <290 +/- 17 ms. Delayed motion areas (cut-off LMT > 300 ms) showed no slowing of conduction. Wall motion time corrected for differences in electrical activation (LMT-LAT) was significantly longer in delayed (289 +/- 34 ms) than in regular (204 +/- 24 ms) motion areas (P = 0.002). Delayed motion segments were hypokinetic on echocardiography and presented a lower maximum inward motion (9.9 +/- 1.1 mm) compared to regular segments (10.9 +/- 1.2 mm) on electromechanical maps (P = 0.004). Viability, however, was preserved with unipolar and bipolar voltage amplitude >7 mV and >1.5 mV for 79% of all delayed motion areas. CONCLUSION: Dyssynchronous segments of an ischemic myocardium show unimpaired local activation but slow wall motion, thereby limiting the benefit of ventricular preexcitation via CRT.

Potential and clinical utility of stem cells in cardiovascular disease.

The recent identification of bone marrow-derived adult stem cells and other types of stem cells that could improve heart function after transplantation have raised high expectations. The basic mechanisms have been studied mostly in murine models. However, these experiments revealed controversial results on transdifferentiation vs transfusion of adult stem cells vs paracrine effects of these cells, which is still being debated. Moreover, the reproducibility of these results in precisely translated large animal models is still less well investigated. Despite these weaknesses results of several clinical trials including several hundreds of patients with ischemic heart disease have been published. However, there are no solid data showing that any of these approaches can regenerate human myocardium. Even the effectiveness of cell therapy in these approaches is doubtful. In future we need in this important field of regenerative medicine: i) more experimental data in large animals that are closer to the anatomy and physiology of humans, including data on dose effects, comparison of different cell types and different delivery routes; ii) a better understanding of the molecular mechanisms involved in the fate of transplanted cells; iii) more intensive research on genuine regenerative medicine, applying genetic regulation and cell engineering.

Endocardial electrogram analysis after intramyocardial injection of mesenchymal stem cells in the chronic ischemic myocardium.

BACKGROUND: Cell injection therapies have been introduced for the treatment of patients with coronary heart disease. However, intramyocardial injection of bone marrow (BM)-derived cells may generate proarrhythmogenicity. METHODS: Two weeks after the placement of a circumflex artery-ameroid constrictor, 21 pigs received mesenchymal stem cells (MSC, n = 9), mononuclear (BM)-derived stem cells (MNC, n = 6), and placebo (n = 6) using a electromechanical mapping (EMM)-guided percutaneous transendocardial injection catheter. At week 6, EMM was repeated and the injected areas were analyzed in detail to evaluate local bipolar electrogram fragmentation, duration, and amplitude. Myocardial fibrosis was evaluated by a quantitative histological analysis. RESULTS: At week 6, the injection of MSC or MNC did not increase local electrogram fragmentation (MSC group: 1.4 +/- 0.3 vs. 1.3 +/- 0.2; MNC group: 1.4 +/- 0.2 vs. 1.3 +/- 0.2; P = NS), prolong electrogram duration (MSC group: 27.1 +/- 7.8 ms vs. 23.7 +/- 2.0 ms; MNC group: 27.8 +/- 3.5 ms vs. 26.8 +/- 5.6 ms; P = NS), or decrease bipolar voltages (MSC group 2.7 +/- 0.9 mV vs. 2.8 +/- 1.0 mV; MNC group 2.0 +/- 1.0 mV vs. 1.7 +/- 0.4 mV). From week 2 to week 6, mean left ventricular ejection fraction increased in the MSC group (37.9 +/- 4.2% vs. 45.9 +/- 2.2%; P = 0.039) only. Histological analysis of the ischemic regions revealed 17.6 +/- 5% myocardial fibrosis in the MNC group vs. 13.6 +/- 3.4% MSC vs. 28.7 +/- 8.7% in the control group (P = 0.038 and P = 0.013). No death occurred in any animal after the injection procedure. CONCLUSION: Intramyocardial injection of MSC or MNC do not increase fragmentation and duration of endocardial electrograms in the injected ischemic myocardium but attenuate ischemic damage and therefore may not create an electrophysiological substrate for reentry tachycardias.

Transplantation of bone marrow-derived stem cells improves myocardial diastolic function: strain rate imaging in a model of hibernating myocardium.

BACKGROUND: The aim of this study was to evaluate the cardioprotective effects of bone marrow-derived stem cells on myocardial compliance in a chronic ischemia model regarding strain rate (SR) parameters during dobutamine stress echocardiography (DSE). METHODS: Ameroid constrictors were placed around the circumflex arteries of 23 domestic pigs to induce chronic vessel occlusions. Fifteen pigs received transendocardially bone marrow derived stem cells, and 8 received placebo injections (a 0.9% solution of NaCl) into the ischemic region. At week 6, the animals were evaluated regarding myocardial fibrosis, neovascularization, apoptosis, and diastolic function during DSE. RESULTS: Stem cell-injected hearts showed significantly less fibrosis, higher ejection fractions, significant neovascularization, and less ventricular dilatation than controls (P < .05). Strain rate imaging revealed improved diastolic function, with higher early diastolic SR values and lower E/Ea ratios compared with controls (P < .05). Early diastolic SR during DSE identifies viable myocardium (extent of fibrosis, r = 0.86, P = .0001). CONCLUSION: The endocardial injection of stem cells improves diastolic function in chronic ischemic myocardium and helps attenuate postinfarction remodeling.

German stereotaxis-guided percutaneous coronary intervention study group: first multicenter real world experience.

BACKGROUND: The Niobe Stereotaxis system consists of two 0.8 Tesla magnets and a navigation software allowing to move specially designed coronary wires. AIM: The aim of this observational multicenter study was to systematically evaluate the capability of the Stereotaxis Niobe Magnetic Navigation system to facilitate wire navigation during percutaneous coronary intervention (PCI), to determine the success rate of magnetically guided PCIs in a real-world setting, and to analyze procedure-related variables influencing the outcome data. METHODS: One hundred and fifty seven patients underwent magnetically guided PCI in three German centers. Demographic variables of the patients, lesion quality determined by quantitative coronary angiography, success rate of the procedure as well as radiation time were analyzed. A subanalysis was performed for two periods (06/04-10/06 and 10/06-10/07) owing to a second generation of wires which was introduced at the beginning of the second period and procured-related learning curves of the operators. RESULTS: Mean age of the patients was 65 +/- 0.4 years (82% male, 18% female). 25% of the patients were diabetics. The lesions were characterized by high complexity (11% AHA type A, 25% type B1, 38% type B2, 25% type C). Mean percent lesion stenosis was 83.7 +/- 11.9%. The total fluoroscopy time was 13.2 +/- 0.3 min and the fluoroscopy time to cross lesion was 90.4 +/- 62.2 s. The overall success rate of the magnetically guided approach was 89%. All failures occurred within the first period were. In these cases, 80% of the failures could be successfully treated after switching to the conventional wires. On the other hand, between 10/06 and 10/07 three conventional PCI failures could be successfully treated using the Stereotaxis system. CONCLUSIONS: Magnetically guided PCI represents a promising tool for the treatment of dedicated lesions. There is a marked difference in the success rates of the method between the two different time periods which were analyzed, reflecting advances in the wire development and learning curves of the respective operators. Randomized controlled trials are required to determine the method's overall value and to identify subgroups that may particularly benefit.

Combined delivery approach of bone marrow mononuclear stem cells early and late after myocardial infarction: the MYSTAR prospective, randomized study.

BACKGROUND: Combined intracoronary and intramyocardial administration might improve outcomes for bone-marrow-derived stem cell therapy for acute myocardial infarction (AMI). We compared the safety and feasibility of early and late delivery of stem cells with combined therapy approaches. METHODS: Patients with left ventricular ejection fraction less than 45% after AMI were randomly assigned stem cell delivery via intramyocardial injection and intracoronary infusion 3-6 weeks or 3-4 months after AMI. Primary end points were changes in infarct size and left ventricular ejection fraction 3 months after therapy. RESULTS: A total of 60 patients were treated. The mean changes in infarct size at 3 months were -3.5 +/- 5.1% (95% CI -5.5% to -1.5%, P = 0.001) in the early group and -3.9 +/- 5.6% (95% CI -6.1% to -1.6%, P = 0.002) in the late group, and changes in ejection fraction were 3.5 +/- 5.6% (95% CI 1.3-5.6%, P = 0.003) and 3.4 +/- 7.0% (95% CI 0.7-6.1%, P = 0.017), respectively. At 9-12 months after AMI, ejection fraction remained significantly higher than at baseline in both groups. In the early and late groups, a mean of 200.3 +/- 68.7 x 10(6) and 194.8 +/- 60.4 x 10(6) stem cells, respectively, were delivered to the myocardium, and 1.30 +/- 0.68 x 10(9) and 1.29 +/- 0.41 x 10(9) cells, respectively, were delivered into the artery. A high number of cells was required for significant improvements in the primary end points. CONCLUSIONS: Combined cardiac stem cell delivery induces a moderate but significant improvement in myocardial infarct size and left ventricular function.

A prospective study on ultrasound-guided percutaneous thrombin injection for treatment of iatrogenic post-catheterisation femoral pseudoaneurysms.

BACKGROUND: The purpose of this study was to evaluate prospectively the safety and efficacy of bovine thrombin injection for the treatment of iatrogenic post-catheterisation pseudoaneurysms. METHODS AND RESULTS: A total of 274 patients (90 women, 184 men, 69.8+/-7 years) with iatrogenic femoral pseudoaneurysms were treated by ultrasound-guided thrombin injection (UGTI). The deepest pseudoaneurysm chamber was entered with a 0.90x40 mm or 90 mm needle and bovine thrombin (solution of 1000 U/ml) was injected. Pseudoaneurysms were associated with diagnostic cardiac catheterisation, percutaneous coronary intervention or invasive electrophysiologic investigation. The majority of the patients were under antiplatelet therapy with aspirin or clopidogrel or both, and additional low dose heparin therapy. A total of 52 patients were treated with either phenprocoumon or enoxaparine body weight adjusted. UGTI was primary successful in 267 of 274 patients (97%). In 3 of 7 patients with a remaining pseudoaneurysm a second injection was required. Three patients were treated by ultrasound-guided compression. One patient was treated by surgical repair of the pseudoaneurysm 1 day after UGTI because a further pseudoaneurysm developed under phenprocoumon therapy. UGTI-related complications such as significant arterial thrombotic events or allergic reactions did not occur. 75 patients (27%) were evaluated by an additional sonography after 3 months to assess the long-term effect. CONCLUSION: UGTI was well tolerated, safe and primarily effective in 97% of patients with iatrogenic femoral pseudoaneurysms. Anticoagulant use did not hinder successful thrombosis. UGTI should be considered as first-line therapy for the treatment of post-catheterisation pseudoaneurysms.

Intramyocardial transplantation of bone marrow-derived stem cells: ultrasonic strain rate imaging in a model of hibernating myocardium.

BACKGROUND: The aim of this study was to evaluate potential cardioprotective effects of bone marrow-derived stem cells in chronic ischemic myocardium regarding strain rate parameters during dobutamine stress echocardiography. METHODS: An ameroid constrictor was placed around the circumflex artery in 23 pigs to induce hibernating myocardium. Pigs received autologous mesenchymal stem cells (auto MSCs), allogeneic MSC (allo MSC), autologous mononuclear cells (auto MNCs), or placebo injections into the ischemic region. During dobutamine stress echocardiography, peak systolic strain rates (SR(sys)) and systolic and postsystolic strain values (epsilon(sys), epsilon(ps)) were determined. The animals were evaluated regarding myocardial fibrosis, neovascularization, apoptosis, and myocardial beta-adrenergic receptor density. RESULTS: The median ejection fraction was reduced in the control group compared with the auto MSC-, allo MSC-, and auto MNC-treated pigs (36.5% vs 46.0% vs 46.0% vs 41.5%; P = .001, respectively). Histopathology revealed a decreased myocardial fibrosis in auto MSC- (16.3%), allo MSC- (11.3%), and auto MNC- (16.7%) treated pigs compared with controls (31.0%; P = .004). The fibrosis and echocardiographic deformation data correlated in the posterior walls: rest peak SR(sys)r = -0.92; epsilon(sys)r = -0.86; 10 microg dobutamine stimulation peak SR(sys)r = -0.88, epsilon(sys), r = -0.87 (P = .0001). CONCLUSION: Endocardial injection of stem cells may induce cardioprotective effects in chronic ischemic myocardium and helps to keep the ischemic myocardium viable.

Cardiac arrest and successful resuscitation in a patient with Tako-Tsubo Cardiomyopathy.

Tako-Tsubo Cardiomyopathy (TTC) is described as transient left ventricular (LV) dysfunction without coronary artery stenoses. Typically the onset of TTC-syndrome is following emotional or physical stress. As an acute cardiac syndrome it is mimicking ST-elevation myocardial infarction. In this case we report from a 73-year old woman presenting with cardiac arrest after a long-distance bus-tour, and ongoing resuscitation to our ICU. Advanced life support with temporary ventricular pacing was continued until onset of stable spontaneous circulation. Left ventricular angiography revealed normal coronary arteries and the typical apical ballooning phenomenon. Echocardiographic findings resolved completely within 10 days. The patient survived, achieved good cerebral recovery (CPC 1) and was alert and fully oriented on discharge after 18 days.

Stenting of unprotected left main stem stenosis: Results from a German single-centre registry.

OBJECTIVE: To elucidate the influence of drug-eluting stents (DESs) on interventional therapy of de novo unprotected left main stem (LMS) lesions in a hospital with on-site cardiac surgery. METHODS AND RESULTS: A retrospective study of all patients with unprotected LMS angioplasty from 1999 to 2005 was conducted with regard to clinical and procedural data, and follow-up data. Fifty-four patients with unprotected LMS stenosis were treated inter-ventionally. Of these patients, 16 were treated with DESs. Seven patients presented with cardiogenic shock. During their hospital stay, four patients died (all treated with bare metal stents [BMSs], three initially presenting with cardiogenic shock). Follow-up data for 53 patients (98%) were obtained. Median follow-up time was 24 months (25th percentile, 12 months; 75th percentile, 35 months). Survival after nine months was 87% (81% from the BMS-treated group, and 100% from the DES-treated group). Control angiography had been performed in 36 patients (67%). Patients with unprotected LMS with an angiographic follow-up had a higher nine-month survival rate than patients without (36 of 36 patients [100%] versus 10 of 17 patients [59%], respectively; P<0.0001). Target lesion revascularization rate was 19% in both the BMS and the DES groups. Methods of revascularization did not vary significantly between the groups. CONCLUSIONS: In the present study of selected patients with LMS stenosis, the use of DESs showed a low mortality rate but did not have a clear effect on target lesion revascularization rate compared with BMSs. A close follow-up appears to be mandatory to achieve acceptable results.

Strain rate imaging for functional quantification of the left atrium: atrial deformation predicts the maintenance of sinus rhythm after catheter ablation of atrial fibrillation.

AIMS: The aim of the study was to investigate the atrial myocardial deformation properties using ultrasound strain rate (SR) imaging in patients after catheter ablation of atrial fibrillation (AF) and to compare its prognostic value in maintaining sinus rhythm. METHODS AND RESULTS: A total of 118 patients with AF (74 paroxysmal AF, 44 persistent AF) underwent transthoracic echocardiography with Doppler-derived SR examinations before and after ablation as well as during 3 months of follow-up (FU). Peak SR and strain (S) were measured at each left atrium (LA) segment (septal, lateral, anterior, inferior) during systole (LAs) and at early (LAe) and late diastole (LAa). Clinical and echocardiographic parameters of patients with maintained sinus rhythm during FU were compared with those with recurrent AF and controls (n = 25 patients). Of 118 patients 82 (69%) showed stable sinus rhythm during FU. Atrial myocardial properties after catheter ablation differed significantly in patients with paroxysmal AF (SR-LAs 2.5 s(-1), S-LAs 30%, SR-LAa -2.2 s(-1)) from patients with persistent AF (SR-LAs 2.3 s(-1), S-LAs 25%, SR-LAa -1.9 s(-1)) and controls (SR-LAs 4.1 s(-1), S-LAs 88%, SR-LAa -2.9 s(-1)) (P = 0.011). Best individual predictors of sinus rhythm maintenance were cut-off values of >2.25 s(-1) for septal and inferior SR-LAs and of >19.5% for inferior S-LAs (P < 0.001). LA deformation properties increased in patients with maintained sinus rhythm during FU in contrast to patients with recurrent AF (P = 0.001). CONCLUSION: SR imaging enables the quantitative assessment of the LA function and can be considered as a potential marker of atrial reverse remodelling. Patients with higher atrial S and SR after catheter ablation appear to have a greater likelihood of maintenance of sinus rhythm. This may have further implications for the anticoagulation regime and the risk of cardioembolic complications.

Tako-Tsubo cardiomyopathy characteristics in long-term follow-up.

UNLABELLED: Tako-Tsubo cardiomyopathy (TTC) is described as left ventricular (LV) dysfunction with the phenomenon of "apical ballooning", rapidly resolving, without coronary artery stenoses. METHODS: Fifteen patients with TTC and transthoracic echocardiography (TTE) at their admission, were reviewed (2001 to 2006). Follow-up (F/U) TTE was performed in varying intervals. To compare diameters of posterior wall (PW), interventricular septum (IVS), left atrium (LA), LV in end-diastole (LVED) and LV in end-systole (LVES) and valve insufficiencies, patients with comparable F/U are selected. RESULTS: Fourteen patients were female (mean age 69.6 years). Angiography demonstrated LV systolic dysfunction with mean ejection fraction (EF) of 31.3%. In the acute-phase (day 0 to day 3), TTE showed a mean EF of 35.7%, not significantly different from EF obtained in angiography. Short-term F/U was performed in 9 patients after median time-interval of 20 days with an increase to a mean EF of 58.8%. F/U in 2006 has been performed in 10 patients (median time-interval 18.7 months) and showed normal EF. No significant difference in diameters of LA, LVED and LVES could be obtained comparing baseline and long-term data (p=0.493, p=0.790 and p=0.275). PW and IVS were significantly thicker at baseline compared to TTE > or = day 62 of F/U (p=0.003 and p=0.026). At baseline mitral valve insufficiency (MI) was mild in 50.0% and moderate in 12.5%, mild and moderate tricuspid valve insufficiency (TI) was recognized in 50% (25% respectively). MI and TI were regredient in F/U. In three patients an intraventricular systolic flow acceleration could be detected in the acute phase. CONCLUSIONS: Characteristics of TTC, besides transient LV apical ballooning are also a significant change in LV wall thickness and reversible valve insufficiencies.