Exercise tissue Doppler echocardiography with strain rate imaging in healthy young individuals: feasibility, normal values and reproducibility

PURPOSE OF THE STUDY

The study was done to determine the clinical feasibility and reproducibility of tissue Doppler echocardiography (TDE) with strain rate imaging (SRI) at rest and under physical exercise in healthy young individuals and to report normal values for parameters of regional myocardial function under exercise.

METHODS

Forty-five young volunteers (age 9-29 years) underwent echocardiography with TDE/SRI at rest and during a bicycle exercise test (2 W/kg body weight).

RESULTS

Velocities could be obtained in 93% of segments, whereas strain rate was measurable at least in 80% of segments. Inter- and intraobserver variability for measurement of velocities under exercise was 14% and 9%, respectively for strain rate 28% and 20%. Except for peak strain, values for all other parameters were higher during exercise with the clearest response in the left lateral and the right ventricular wall.

CONCLUSIONS

(1) Tissue Doppler with strain rate imaging is a practical and robust method for assessment of regional function of both ventricles under exercise. (2) Systolic motion, local myocardial relaxation and contractility increased significantly under physical exercise. These normal values obtained from healthy young subjects can serve as a reference database for further clinical studies.

Immunopathogenesis of dilated cardiomyopathy. Evidence for the role of TH2-type CD4+T lymphocytes and association with myocardial HLA-DR expression

BACKGROUND

An immunological pathogenesis underlying dilated cardiomyopathy and myocarditis has been suggested on the basis of the subtype of lymphocyte infiltrates and the degree of HLA expression in cardiac tissue. In the present study, we investigated the relation between the peripheral CD4+T-cell subset and the degree of HLA expression in the heart.

METHODS

Fifty-four patients with heart insufficiency included in the study were biopsied after coronary heart disease had been excluded. Immunohistological staining of the left ventricular tissue were performed employing anti-CD3, -CD4, -CD8, -CD14, and HLA-DR monoclonal antibodies. Intracellular expression of IL-2, IL-4, IL-5, IFN-gamma, and TNF-alpha in peripheral CD4+T lymphocytes was determined using flow cytometry. The severity of heart insufficiency was determined by measurement of brain natriuretic peptide (BNP) and the NYHA class. On the basis of HLA expression in the heart, the patients were divided into three groups: Group I (mild-to-none), Group II (moderate), and Group III (strong-to-very strong).

RESULTS

Of the 54 patients included in this study, 33 (61%) patients were diagnosed as having idiopathic dilated cardiomyopathy and 10 (18.5%) borderline or healing myocarditis according to the Dallas criteria. Both patient groups were found in all three HLA-DR groups. There was no difference in BNP level or NYHA class between the three groups. However, a significant difference in the proportion of CD4+T lymphocytes producing IL-2 (39.2 versus 21.8%), IFN-gamma (19.5 versus 7.8%), and TNF-alpha (35.8 versus 16.1%) between Groups I and III could be detected, whereas the distribution of IL-4 and IL-5 producing CD4+T lymphocytes was similar. The myocardium of Group III patients exhibited a significant higher number of CD3+T cells (11.4 versus 4.3 per mm2) and CD4+T cells (4.7 versus 0.8 per mm2) compared to Group I patients, while no difference existed with respect to CD8+T cells.

CONCLUSION

High myocardial expression of the HLA-DR antigen is associated with an increase of peripheral-blood CD4+T lymphocytes expressing cytokines of the TH2 subset. The degree of HLA-DR expression is not associated with the degree of heart insufficiency or underlying diagnosis, but correlates with an increase of activated T cells in the myocardium. The data suggest that CD4+T lymphocytes infiltrating cardiac tissue may play a pathogenic role in dilated cardiomyopathy.

Determinants of coronary steal in chronic total coronary occlusions donor artery, collateral, and microvascular resistance

OBJECTIVES

We aimed to assess the mechanisms of coronary steal by direct hemodynamic measurements of the collateral circulation in chronic total coronary occlusions (CTO).

BACKGROUND

Coronary steal may cause ischemia despite well-developed collaterals in coronary artery disease.

METHODS

Fifty-six patients were studied during recanalization of a CTO. Before recanalization, the fractional flow reserve in the donor artery (FFR(D)) at the takeoff of the collaterals and the coronary flow reserve were recorded. After crossing the occlusion, the distal coronary flow velocity was measured by a Doppler wire (APV(Occl)), and distal pressure by a pressure wire. Changes of these parameters were assessed during intravenous adenosine (140 microg/kg/min). Resistance indexes for the donor artery (R(D)), collaterals (R(C)), and microcirculation (R(P)) were calculated.

RESULTS

Adenosine caused a decrease of APV(Occl) (i.e., coronary steal, in 26 patients [group S], an increase in 19 patients [group R], and no change in 11 patients). The FFR(D) was lower in group S. R(D) and R(C) increased in group S, while R(D) did not change significantly and R(C) decreased in group R. Patients with steal had more severe regional dysfunction. Patients with steal but without an FFR(D) <0.8 tended to have an impaired microvascular function.

CONCLUSIONS

We could demonstrate that coronary steal in man is mainly due to a hemodynamically significant donor artery lesion, but can also occur due to an impaired vasodilatory reserve of the microcirculation in the absence of a donor artery lesion. Coronary steal may have an adverse influence on the preservation of myocardial function by collaterals.

Analysis of Location and Pattern of Target Vessel Failure in Chronic Total Occlusions after Stent Implantation and Its Potential for the Efficient Use of Drug-Eluting Stents

OBJECTIVES

The recanalization of chronic total occlusions (CTOs) is a complex procedure with high rates of target vessel failure (TVF), i.e., restenosis or reocclusion. Little is known about the localization of lesion recurrence, and whether extensive stenting should be performed. In this prospective analysis, the area at high risk for restenoses after recanalization of CTO was localized.

METHODS

Angiograms of 97 consecutive patients and control angiograms after a mean period of 5 +/- 1.3 months were analyzed for location and length of the CTO and the sites of recurrences.

RESULTS

In total, 158 stents were implanted (1.6 +/- 0.9 per lesion). Restenoses occurred in 39% and reocclusions in 17% of the patients. Patients with a TVF had a longer CTO than patients without TVF (17.9 +/- 10.2 vs 13.9 +/- 8.6 mm; P = 0.023). The TVF rate increased with the number of implanted stents. The stent diameter was smaller in lesions with subsequent reocclusions than in restenotic and nonrestenotic lesions (2.8 +/- 0.5 vs 3.0 +/- 0.4 and 3.2 +/- 0.4 mm resp.; P = 0.007). Analyzing the localization of the 38 restenoses, we only found 45% restricted to the area of the former CTO, while 82% were located in the area of the former CTO plus 10 mm in proximal and distal direction.

CONCLUSIONS

Stents should not only cover the site of the CTO, but should enclose the high-risk area of recurrence within 10 mm proximal and distal of the former CTO. This may guide the rational use of drug-eluting stents.

Expression of androgen-binding protein (ABP) in human cardiac myocytes

Cardiomyocytes are known to be androgen targets. Changing systemic steroid levels are thought to be linked to various cardiac ailments, including dilated cardiomyopathy (DCM). The mode of action of gonadal steroid hormones on the human heart is unknown to date. In the present study, we used high-resolution immunocytochemistry on semithin sections (1 microm thick), IN SITU hybridization, and mass spectrometry to investigate the expression of androgen-binding protein (ABP) in human myocardial biopsies taken from male patients with DCM. We observed distinct cytoplasmic ABP immunoreactivity in a fraction of the myocytes. IN SITU hybridization with synthetic oligonucleotide probes revealed specific hybridization signals in these cells. A portion of the ABP-positive cells contained immunostaining for androgen receptor. With SELDI TOF mass spectrometry of affinity purified tissue extracts of human myocardium, we confirmed the presence of a 50 kDa protein similar to ABP. Our observations provide evidence of an intrinsic expression of ABP in human heart. ABP may be secreted from myocytes in a paracrine manner perhaps to influence the bioavailabity of gonadal steroids in myocardium.

Turbulent flow as a cause for underestimating coronary flow reserve measured by Doppler guide wire

Background

Doppler-tipped coronary guide-wires (FW) are well-established tools in interventional cardiology to quantitatively analyze coronary blood flow. Doppler wires are used to measure the coronary flow velocity reserve (CFVR). The CFVR remains reduced in some patients despite anatomically successful coronary angioplasty. It was the aim of our study to test the influence of changes in flow profile on the validity of intra-coronary Doppler flow velocity measurements in vitro. It is still unclear whether turbulent flow in coronary arteries is of importance for physiologic studies in vivo.

Methods

We perfused glass pipes of defined inner diameters (1.5 – 5.5 mm) with heparinized blood in a pulsatile flow model. Laminar and turbulent flow profiles were achieved by varying the flow velocity. The average peak velocity (APV) was recorded using 0.014 inch FW. Flow velocity measurements were also performed in 75 patients during coronary angiography. Coronary hyperemia was induced by intra-coronary injection of adenosine. The APV maximum was taken for further analysis. The mean luminal diameter of the coronary artery at the region of flow velocity measurement was calculated by quantitative angiography in two orthogonal planes.

Results

In vitro, the measured APV multiplied with the luminal area revealed a significant correlation to the given perfusion volumes in all diameters under laminar flow conditions (r² > 0.85). Above a critical Reynolds number of 500 – indicating turbulent flow – the volume calculation derived by FW velocity measurement underestimated the actual rate of perfusion by up to 22.5 % (13 ± 4.6 %). In vivo, the hyperemic APV was measured irrespectively of the inherent deviation towards lower velocities. In 15 of 75 patients (20%) the maximum APV exceeded the velocity of the critical Reynolds number determined by the in vitro experiments.

Conclusion

Doppler guide wires are a valid tool for exact measurement of coronary flow velocity below a critical Reynolds number of 500. Reaching a coronary flow velocity above the velocity of the critical Reynolds number may result in an underestimation of the CFVR caused by turbulent flow. This underestimation of the flow velocity may reach up to 22.5 % compared to the actual volumetric flow. Cardiologists should consider this phenomena in at least 20 % of patients when measuring CFVR for clinical decision making.

Creatine supplementation improves muscle strength in patients with congestive heart failure

BACKGROUND

Both, cardiac and skeletal muscle creatine levels are depressed in patients with congestive heart failure (CHF). Oral supplementation of creatine (Cr) could increase physical performance in healthy volunteers. We therefore hypothesized that oral creatine supplementation improves skeletal muscle strength, quality of live and symptom-limited performance in patients with CHF.

METHODS

In a double-blind, placebo-controlled and crossover-designed study, 20 patients suffering from congestive heart failure more than 6 months and a peak oxygen uptake (peak VO2) below 20 ml/min/kg received 4 x 5 g Cr daily vs. placebo for 6 weeks and were crossed over for the following 6 weeks. Peak VO2, VO2 at the anaerobic threshold (VO2AT), ejection fraction (EF), distance in 6-minute-walk-test (6 min W), and muscle strength (Modified Sphygmomanometer (MS)) were determined at baseline, after 6, and after 12 weeks. Dyspnoea after 6-minute-walk-test was measured using the Borg Scale. Quality of live was assessed with the Minnesota Living with Heart Failure Questionnaire (MLHFQ).

RESULTS

13 of 20 Patients finished the study. After 6 weeks of creatine supplementation there was a significant increase in body weight and muscle strength compared to baseline and placebo (p < 0.05). However, there was no significant change in peak VO2, VO2AT, walking distance, quality of life assessment and EF.

CONCLUSION

Short-term creatine supplementation inaddition to standard medication in patients with CHF leads to an increase in body weight and an improvement of muscle strength. This effect is restricted to the time of supplementation.

[Implantation of a re-synchronization device in a patient with persistent left superior vena cava-a case report]

We report an implantation of a cardiac re-synchronization system in a patient with persistent left superior vena cava. This anomaly occurs in 0.3 to 0.5% of healthy individuals and remains usually asymptomatic. Variations of the superior vena cava should be considered in venous catheterization and other procedures such as implantation of pacemaker and ICD systems as well as port catheter insertion. In re-synchronization systems, persistent left superior vena cava can be an obstacle for cannulation of the coronary sinus and placement of a transvenous left ventricular lead.

Resting 12-lead electrocardiogram as a reliable predictor of functional recovery after recanalization of chronic total coronary occlusions

BACKGROUND

A major goal of revascularization is the recovery of left ventricular (LV) function. Nuclear imaging techniques are widely used for detecting recovery of function with a good sensitivity, but only moderate specificity. Predictors of recovery in chronic total coronary occlusions (CTO) are not investigated.

HYPOTHESIS

The 12-lead-resting electrocardiogram (ECG) is a predictor of LV recovery after successful recanalization of CTO.

METHODS

Successful recanalization of CTO was performed in 127 patients. Of these, 62 patients, who constitute the study group, had impaired regional wall motion prior to recanalization. The 12-lead resting ECG was evaluated for Q-wave areas and parameters of QT dispersion. Impairment of regional wall motion was evaluated by LV angiogram at baseline and at follow-up.

RESULTS

Angiographic follow-up after 5 +/- 1.4 months documented reocclusion in eight patients. Complete follow-up with a patent coronary artery and an ECG without bundle-branch block was available in 43 patients. Wall motion severity index (WMSI) improved from -2.92 +/- 0.28 to -1.34 +/- 0.61 (p < 0.001) in patients without Q waves, whereas it was unchanged in patients with Q waves (-3.01 +/- 0.30 and -2.81 +/- 0.32). Absence of Q waves at baseline predicted recovery of regional wall motion with 89% sensitivity and 67% specificity. Positive predictive value for recovery was 68% in patients without Q waves, but only 11% in patients with Q waves. In multivariate analysis, only absence of Q waves predicted improvement in WMSI (p = 0.01).

CONCLUSIONS

In patients with recanalization of CTO, recovery of regional wall motion is reliably predicted by analysis of the resting 12-lead ECG for pathologic Q waves.

Transoesophageal left ventricular pacing in heart failure patients with permanent right ventricular pacing

BACKGROUND

Previous studies of biventricular (BV) pacing for treatment of heart failure (HF) patients with left bundle branch block (LBBB) evaluated responders to BV pacing with acute transvenous left ventricular (LV) pacing and arterial pulse pressure (PP). The aim of this study was to assess transoesophageal LV pacing in evaluation of the haemodynamic response with a view to upgrading responders from permanent right ventricular (RV) pacing to BV pacing.

METHODS AND RESULTS

Ten HF patients (age 62+/-8 years; one female, nine males) in NYHA III, LV ejection fraction 24+/-9% and permanent RV pacing by means of an implanted pacemaker or ICD were tested using transoesophageal LV pacing and PP. Permanently RV-paced HF patients were analysed with transoesophageal atrial sensed LV pacing in VAT mode with a different AV delay (n = 6) and with transoesophageal LV pacing in V00 mode during atrial fibrillation (n = 4). In five responders, PP was higher during transoesophageal LV pacing than PP during RV pacing (74+/-42 versus 57+/-31 mmHg, P = 0.015). Responders were upgraded by means of an LV lead via the coronary sinus in the posterior (n = 1) or posterolateral (n = 4) walls and after attaining a high LV pacing threshold with an epicardial LV lead on the anterior (n = 1) or anterolateral (n = 1) walls. NYHA class improved from 3 to 2+/-0.3 (P = 0.003) during 204+/-120 days follow-up and cardiac output increased from 4.4+/-1.5 to 5.6+/-1.7 l/min (P = 0.027) when comparing BV pacing and optimal AV delay with RV pacing. In five nonresponders, PP was not higher during transoesophageal LV pacing than during RV pacing.

CONCLUSION

Transoesophageal LV pacing may be a useful technique to detect responders to BV pacing in permanently RV-paced HF patients.

Betaxolol is equivalent to carvedilol in patients with heart failure NYHA II or III: result of a randomized multicenter trial (BETACAR Trial)

BACKGROUND

In a recent COMET trial (Lancet 362, 2003:7-13) it could be demonstrated that carvedilol < or = 50 mg/d was superior to metoprolol tartrate < or = 100 mg/d in the treatment of heart failure patients NYHA II-IV.

OBJECTIVES

It was investigated whether the superiority of carvedilol with its beta1, beta2 and alpha-blocking potency will persist in a comparison to a highly selective beta1-blocker with a long plasma half-time such as betaxolol.

METHODS

255 pts. with NYHA II or III heart failure were double-blind randomized and uptitrated to either carvedilol 25 mg bid (n=131) or betaxolol 20 mg od (n=124).

RESULTS

Within 8 months left ventricular ejection fraction (LVEF) increased to the same extent from 30% to 43% (carvedilol) or 31% to 43% (betaxolol) as primary endpoint (ns). 13% of the carvedilol (CAR) patients versus 15% of the betaxolol patients (BET) suffered either from cardiac death or recurrent hospitalizations (cardiac death n=6 (CAR), n=2 (BET), ns). The mean increase in the 6-min walk test was 63 m with CAR and 61 m with BET and the Minnesota living with heart failure questionnaire improved in both groups (ns). Heart rate reduction was pronounced in both groups: CAR 13.1 beats/min, BET 13.6 beats/min.

CONCLUSIONS

The long acting highly selective beta1-blocker betaxolol in an adequate dosage is not inferior to carvedilol in terms of exercise tolerance, safety and effects on left ventricular function.

Detection of coronary microembolisation by Doppler ultrasound during percutaneous coronary interventions

OBJECTIVE

To validate an intracoronary Doppler ultrasound device for high intensity transient signals (HITS) detection and to assess the incidence of HITS during percutaneous coronary intervention (PCI).

METHODS AND RESULTS

In an in vitro model, particle count and number of HITS detected by an intracoronary 0.014 inch Doppler wire were closely correlated (r = 0.97, p < 0.001). In the clinical study, 32 patients (mean (SD) age 61 (11) years; 23 men, nine women) with coronary artery disease were treated with balloon dilatation and stent implantation for a single vessel stenosis. In these patients HITS were detected during PCI in 84% (27 of 32). Reproducibility (r = 0.99, p < 0.001) and interobserver agreement (r = 0.84, p < 0.001) of HITS counts were significant. The number of HITS after stent implantation was significantly higher than after balloon dilatation (11 (7) v 2 (4), p < 0.001). Postprocedural coronary flow velocity reserve (CFVR) was < 2.0 in 55% (16 of 29) of all patients after balloon dilatation and < 2.0 in 23% (six of 26) after stent implantation. The number of HITS after stent implantation did not differ significantly between patients with CFVR < 2.0 and patients with CFVR > or = 2.0 (12 (8) v 10 (7), not significant).

CONCLUSIONS

Embolic particles can be detected as HITS by an intracoronary Doppler ultrasound device. Coronary microembolism is often observed during PCI, especially after stent implantation. However, the incidence of HITS alone does not explain a reduced CFVR after PCI.

Treatment with granulocyte colony-stimulating factor for mobilization of bone marrow cells in patients with acute myocardial infarction

BACKGROUND

This study was undertaken to evaluate the hypothesis that treatment with granulocyte colony-stimulating factor (G-CSF) to mobilize bone marrow cells (BMCs) is feasible and safe and promotes neovascularization and myocardial function in patients with acute myocardial infarction.

METHODS

Fourteen patients in the treatment group and 9 patients in the control group were enrolled in this prospective, nonrandomized, open-label study. Forty-eight hours after successful recanalization and stent implantation, the patients of the treatment group received 10 microg/kg body weight per day G-CSF subcutaneously for mean treatment duration of 7.0 +/- 1.0 days. Nine patients fulfilled the entry criteria but refused participation and served therefore as control group. In both groups, regional wall motion and perfusion was evaluated with electrocardiogram-gated sestamibi single-photon emission computed tomography imaging and ejection fraction with radionuclidventriculography before discharge and after 3 months.

RESULTS

No severe side effects of G-CSF treatment were observed. There was a significant improvement of the regional wall motion and perfusion within the treatment group (P < .0001) and between the treatment and control group (P < .05 and P < .01, respectively). Ejection fraction in the treatment group increased from 0.40 +/- 0.11 to 0.48 +/- 0.13 (P < .01), whereas in the control group, ejection fraction increased from 0.40 +/- 0.13 to 0.43 +/- 0.13 (P = .049). A control angiography of the treatment group after 12.4 +/- 6.6 months showed an in-stent restenosis in 1 patient.

CONCLUSION

In patients with acute myocardial infarction, treatment with G-CSF to mobilize BMCs is feasible and safe and seems to be effective under clinical conditions. The therapeutic effect might be attributed to BMC-associated promotion of myocardial regeneration and neovascularization.

The importance of the gastrointestinal system in the pathogenesis of heart failure

Chronic heart failure (CHF) is a multi-organ disease with increasing evidence for the involvement of the gastrointestinal (GI) system in this syndrome. In recent research, the gut has received very little attention from cardiologists as its role in the pathogenesis of cardiovascular disease is poorly understood. Intestinal ischaemia may play an important role in bacterial translocation by increasing bowel permeability. Decreased cardiac function can reduce bowel perfusion and so clearly impairs the function of the intestinal barrier. There is an increasing evidence to suggest that a 'leaky' bowel wall may lead to translocation of bacteria and/or endotoxin, which may be an important stimulus for inflammatory cytokine activation in CHF. Impaired functioning of the GI system may also contribute to malnutrition and cachexia in CHF. It is hoped that by improving our understanding of the role of the gut in cardiac disease will lead to the development of novel therapeutic strategies in the future.

Lack of association between Chlamydia Pneumoniae serology and endothelial dysfunction of coronary arteries

BACKGROUND

Recent publications brought up the hypothesis that an infection with Chlamydia Pneumoniae (CP) might be a major cause of coronary artery disease (CAD). Therefore, we investigated whether endothelial dysfunction (ED) as a precursor of atherosclerosis might be detectable in patients with previous infection with CP but without angiographic evidence of CAD.

METHODS

We included 16 patients (6 male / 10 female) of 52 consecutive patients with normal coronary angiography who had typical angina pectoris and pathologic findings in the stress test. Exclusion criteria were: active smoker, elevated cholesterol, hypertension, age > 65 years, diabetes mellitus, treatment with ACE-inhibitors, or known CAD. Blood sample analysis for serum titer against CP (aCP-IgG) was performed after coronary angiography. We looked for endothelial dysfunction analyzing the diameter of the left anterior descending coronary artery (LAD) before and after acetylcholine (ACh) i. c. Quantitative analysis of luminal diameter (LD) was performed in at least two planes during baseline conditions and after ACh for 2 minutes in dosages of 7.2 microg/min and 36 microg/min with an infusion speed of 2 ml/min. Using Doppler guide wire, the coronary flow velocity was measured continuously in the LAD. The coronary flow velocity reserve (CFVR) was measured after 20 microg adenosine i. c.

RESULTS

10 patients had an elevated aCP-IgG (> 1:8). 6 patients with negative titers (aCP-IgG <or= 1:8) served as control (CTRL). Both groups were comparable in age, gender, angina class, results of non-invasive stress-test and the baseline values of LD and flow. In the CP positive group 3 patients (30%) did not show an increase of LD after ACh as evidence of ED. In the CTRL group 4 patients (67 %) had ED. There was no association between aCP-IgG and changes of coronary blood flow after ACh. All patients showed normal CFVR (3.0 +/- 0.27) irrespective of their aCP-IgG values.

CONCLUSION

In patients with typical symptoms of coronary ischemia but without angiographically visible CAD and absence of other factors affecting the endothelial function, a previous infection with CP is not associated with endothelial dysfunction.

Outcome after cardiac arrest: predictive values and limitations of the neuroproteins neuron-specific enolase and protein S-100 and the Glasgow Coma Scale

BACKGROUND AND PURPOSE

Patients resuscitated from cardiac arrest are at risk of subsequent death or poor neurological outcome up to a persistent vegetative state. We investigated the prognostic value of several epidemiological and clinical markers and two neuroproteins, neuron-specific enolase (NSE) and S-100 protein (S-100), in 97 patients undergoing cardiopulmonary resuscitation (CPR) after non-traumatic cardiac arrest between 1998 and 2002.

RESULTS

52.6% of the patients died, 28.8% survived with severe, moderate or without neurological disorders, and 18.6% remained in a persistent vegetative state. Unconsciousness>48 h after CPR predicted a 60.6-fold (95% CI 14.3287-257.205, p=0.001) and a Glasgow Coma Scale (GCS)<6 points after 72 h a 11.2-fold (CI 95%, 3.55-36.44, p<0.001) risk of poor neurological outcome. Serum levels>or=65 ng/ml for NSE and >or=1.5 microg/l for S-100 increased the risk of death and persistent vegetative state 16.8 (95% CI 2.146-131.520)- and 12.6 (95% CI 1.1093-99.210)-fold, respectively. By combination of the GCS with elevated serum concentrations of both neuroproteins above the cut off levels on third day after CPR a poor neurological outcome was predicted with a specificity of 100%.

CONCLUSION

The combination of GCS with the serum levels of both neuroproteins at 72 h after CPR permit a more reliable prediction of outcome in post arrest coma than the single markers alone, independent of the application of anaesthetic agents.

Autologous intracoronary mononuclear bone marrow cell transplantation in chronic ischemic cardiomyopathy in humans

BACKGROUND

Recent data suggest that transplantation of autologous bone marrow cells (BMC) may contribute to myocardial repair after acute myocardial infarction. We hypothesized that patients with chronic ischemic cardiomyopathy could also benefit from autologous BMC transplantation in addition to established heart failure therapy.

METHODS AND RESULTS

Five patients with chronic ischemic cardiomyopathy caused by anterior myocardial infarction, 1.3+/-0.5 years ago and open infarct artery, received autologous mononuclear BMC transplantation via balloon catheter in the target vessel at the site of previous occlusion. Patients were followed up at 3 months (left heart catheterisation, 2D-echocardiography, dobutamine stress echocardiography, cardiopulmonary exercise testing) and at 12 months (2D-echocardiography, cardiopulmonary exercise testing). Follow-up examination showed no significant improvement neither in global, regional, and microvascular function, nor in physical performance.

CONCLUSIONS

In this pilot trial intracoronary transplantation of autologous, mononuclear BMC did not lead to any significant improvement in myocardial function and physical performance of patients with chronic ischemic heart disease.

[Cardiopulmonary monitoring in gastroenterological and renal emergencies]

Predominantly elderly and multimorbide patients require frequently intensive care observation and treatment due to acute gastrointestinal and renal disease. Manifest circulatory and rhythm instability, acute heart failure and severe metabolic or electrolyte derangements present indications for submission to a critical care unit. Stabilization of vital functions, control of specific therapeutic procedures (e. g. renal replacement therapy), and early recognition of secondary complications belong to the tasks of intensive care. Beyond a baseline monitoring available procedures comprises a broad spectrum from pulseoxymetrie to pulmonary artery catheter monitoring depending of the need of the individual patient.

Mechanische Herz-Kreislauf-Unterstützung in der Kardiologie

One out of 13 patients with an acute myocardial infarction is endangered of cardiogenic shock. In addition, acute valvular leakage, shunt vitiae, and acute myocarditis can lead to acute myocardial failure. As a therapeutic option, mechanical assist devices offer cardiac support and hemodynamic stabilization under these circumstances. The following minimal-invasive devices are used in cardiology and intensive care medicine: intra-aortic balloon pulsation (IABP), intra-vascular axial screw pumps, extra-corporal centrifugal pumps with and without additional membrane oxygenator. The IABP improves left ventricular function by a systolic reduction of the after-load, and an increase of diastolic blood pressure dependent on myocardial function. In contrast, axial screw pumps and centrifugal pumps can provide circulatory support independently of myocardial function. Mechanical assist devices can prevent irreversible damage not only by offering a reduction of myocardial work load, but also by improving organ perfusion in cardiogenic shock situations. Another indication for mechanical circulatory support depicts high-risk coronary angioplasty if the left ventricular ejection fraction is severely reduced or the target vessel supplies more than 50 % of vital myocardium. In case of irreversible heart failure, turbine pumps or centrifugal pumps offer a stabilization for the patient's transfer to a cardiac surgery center. They can also be used for bridging to heart transplantation in acute situations. Technical improvements will enhance the use of mechanical assist devices in the near future. Especially the development of portable emergency devices will enrich therapeutic possibilities in cardiology and intensive care medicine.

Successful high-risk coronary angioplasty in a patient with cardiogenic shock under circulatory assist with a 16F axial flow pump

We report the case of a 75-year-old patient who suffered from subacute myocardial infarction and severely impaired left ventricular ejection fraction (EF: 17%). Using a novel 16F left ventricular assist device we performed an angioplasty of the right coronary artery, and of the left anterior descending artery. As a result of the circulatory support the patient recovered from cardiogenic shock within 8 hr. At a pump speed of 45,000 rpm the axial flow pump generated flow rates up to 3.3 l/min. The 16F pump cannula was removed using local compression. The EF was 51% at 30-day follow-up examination.

Collaterals and the recovery of left ventricular function after recanalization of a chronic total coronary occlusion

BACKGROUND

A good collateral function in patients with regional myocardial dysfunction may indicate viability with the potential for left ventricular (LV) recovery after revascularization of a chronic total coronary occlusion (CTO).

METHODS

A CTO (duration > 2 weeks) was successfully recanalized in 126 patients. During this procedure, the collateral function was assessed before the first balloon inflation by intracoronary Doppler and pressure wires. Collateral function indexes were calculated. Left ventricular function was assessed by the LV ejection fraction (LVEF) and the wall motion severity index (WMSI [SD/chords]). A repeat angiography was available in 119 patients after 4.9 +/- 1.4 m. An improvement of WMSI > or =1 SD/chord was considered significant.

RESULTS

Left ventricular function was normal in 42%, regional dysfunction with LVEF > or = 0.60 was observed in 16%, and regional dysfunction with LVEF < 0.60 in 42%. The former had a better collateral function than patients with LV dysfunction. In 39% of patients with LV dysfunction, a significant myocardial recovery was observed at follow-up. The collateral function was similar in patients with and without recovery. However, patients with recovery had a lower peripheral resistance as an indicator of a better preserved microvascular integrity.

CONCLUSIONS

Recovery of impaired LV function after revascularization of a CTO is not directly related to the quality of collateral function, as collateral development does not appear to require the presence of viable myocardium. However, a preserved microvascular integrity may be of relevance for myocardial recovery.

Paclitaxel-eluting stents for the treatment of chronic total coronary occlusions: A strategy of extensive lesion coverage with drug-eluting stents

The recanalization of a chronic total coronary occlusion (CTO) is hampered by a high rate of lesion recurrence. The goal of the present study is to assess the effect of paclitaxel-eluting stents in CTOs in a strategy of extensive stent coverage and the optional use of additional bare metal stents (BMSs). In 82 consecutive patients, a CTO (duration > 2 weeks) was successfully recanalized with implantation of one or more Taxus stents. These patients underwent a repeat angiography after 5.0 +/- 1.5 months and were assessed by quantitative angiography. The patients were compared with 82 clinically and lesion-matched patients from a consecutive series of 148 patients with CTOs treated by BMS in the preceding time period. In 21 of the 82 patients, additional lesions in the target artery not directly related to the original occlusion site were treated with BMSs (hybrid approach). The history of diabetes, extent of coronary artery disease, clinical symptoms, and angiographic features were similar in the Taxus and BMS group. Periprocedural adverse events were 3.3% with Taxus and 3.3% with BMS, but 12 months MACE was significantly lower in the group with exclusive use of Taxus (13.3% vs. 56.7%; P < 0.001), mainly due to a lower target lesion revascularization of 10.0% as compared to 53.4% (P < 0.001). There was only one late reocclusion with Taxus (1.7%) as compared to 21.7% with BMS (P < 0.05). However, in the hybrid group, the MACE rate was considerably higher, with 33.3%. Our data of a 80% reduction of target vessel failure as compared to BMS, with a lower risk of late reocclusions without increased acute adverse events, demonstrate the benefit of paclitaxel-eluting stents in CTOs. However, diffuse atherosclerosis in CTOs should be covered completely by the drug-eluting stents.

Prevention of lesion recurrence in chronic total coronary occlusions by paclitaxel-eluting stents

OBJECTIVES

The aim of this research was to assess the efficacy of paclitaxel-eluting stents in chronic total coronary occlusions (CTO).

BACKGROUND

Percutaneous coronary interventions for CTOs are characterized by a high target vessel failure rate.

METHODS

In 48 consecutive patients, paclitaxel-eluting stents (Taxus, Boston Scientific Corp., Natick, Massachusetts) were implanted after successful recanalization of a CTO (duration >2 weeks). Patients underwent an angiography after 6 months and were followed clinically for 12 months. They were compared with 48 lesion- and risk-matched patients with CTOs treated with bare metal stents (BMS). Primary clinical end point was the one-year incidence of major adverse cardiac events (MACE) (death, myocardial infarction, repeat revascularization); secondary end points were the rate of restenosis and re-occlusion.

RESULTS

In-hospital MACE was 4.2% with Taxus, and 2.1% with BMS (p = NS). The one-year MACE rate was 12.5% in the Taxus group, and 47.9% in the BMS group (p < 0.001), which was due to a reduced need for repeat revascularization. The angiographic restenosis rate was 8.3% with Taxus versus 51.1% with BMS (p < 0.001). There was only one late re-occlusion with Taxus (2.1%) as compared with 23.4% with BMS (p < 0.005). The late loss was reduced in the Taxus group by 84% as compared with BMS. All nonocclusive restenoses in the Taxus group were focal and successfully treated by implanting an additional Taxus stent.

CONCLUSIONS

The treatment of CTOs with a paclitaxel-eluting stent drastically reduces MACE and restenosis, and almost eliminates re-occlusion, which is typically frequent with BMS in CTOs. Chronic total coronary occlusion should be a preferred indication for drug-eluting stents.

Transarterial aortic valve replacement with a self expanding stent in pigs

OBJECTIVES

To evaluate the feasibility of percutaneous aortic valve replacement without cardiac arrest in animal experiments.

METHODS

A self expanding nitinol stent, containing pulmonary valves from pigs in its proximal part, was implanted in six pigs (94-118 kg) by means of a 25 French catheter through the left subclavian artery under guidance of fluoroscopy and transoesophageal echocardiography. During stent deployment the original aortic valve was pushed against the aortic wall by the self expanding force of the stent while the new valve was expanded.

RESULTS

It was possible to replace the aortic valve in the beating heart in four pigs (67%) with no complication or relevant drop in blood pressure. The procedure failed in two pigs (33%) due to dysfunction of the catheter device in one case and to problems with correct positioning in the left ventricular outflow tract in the other. After successful stent valve implantation, dopamine was infused in doses of 5 microg/kg/min, 10 microg/kg/min, and 15 microg/kg/min. Cardiac output increased from 4.4 to 8.8 l/min and the mean arterial pressure rose from 79 to 105 mm Hg. The maximum peak to peak pressure gradient across the valve carrying stent reached a maximum of 8 mm Hg under dopamine infusion. All pigs were killed six hours after transvascular aortic valve replacement. The chest was opened, and the left ventricle and the ascending aorta were carefully inspected. There were no signs of malfunction of the implant, of damage of the aortic vessel wall, or of obstruction of the coronary ostia.

CONCLUSIONS

Percutaneous aortic valve replacement with a self expanding nitinol stent in the beating heart is possible. The device was safe under pharmacological stress test. After successful chronic animal experiments, this concept may become a feasible option for treating patients with relevant aortic valve disease but where open heart surgery would be risky.