Safety, feasibility, and long-term results of percutaneous closure of atrial septal defects using the Amplatzer septal occluder without periprocedural echocardiography.

OBJECTIVES: We sought to assess the safety and efficacy of percutaneous closure of atrial septal defects (ASDs) under fluoroscopic guidance only, without periprocedural echocardiographic guidance. BACKGROUND: Percutaneous closure of ASDs is usually performed using simultaneous fluoroscopic and transthoracic, transesophageal (TEE), or intracardiac echocardiographic (ICE) guidance. However, TEE requires deep sedation or general anesthesia, which considerably lengthens the procedure. TEE and ICE increase costs. METHODS: Between 1997 and 2008, a total of 217 consecutive patients (age, 38 ± 22 years; 155 females and 62 males), of whom 44 were children ≤16 years, underwent percutaneous ASD closure with an Amplatzer ASD occluder (AASDO). TEE guidance and general anesthesia were restricted to the children, while devices were implanted under fluoroscopic guidance only in the adults. For comparison of technical safety and feasibility of the procedure without echocardiographic guidance, the children served as a control group. RESULTS: The implantation procedure was successful in all but 3 patients (1 child and 2 adults; 1.4%). Mean device size was 23 ± 8 mm (range, 4-40 mm). There was 1 postprocedural complication (0.5%; transient perimyocarditis in an adult patient). At last echocardiographic follow-up, 13 ± 23 months after the procedure, 90% of patients had no residual shunt, whereas a minimal, moderate, or large shunt persisted in 7%, 1%, and 2%, respectively. Four adult patients (2%) underwent implantation of a second device for a residual shunt. During a mean follow-up period of 3 ± 2 years, 2 deaths and 1 ischemic stroke occurred. CONCLUSION: According to these results, percutaneous ASD closure using the AASDO without periprocedural echocardiographic guidance seems safe and feasible.

Two-year clinical outcome after implantation of sirolimus-eluting and paclitaxel-eluting stents in diabetic patients.

AIMS: Percutaneous coronary intervention (PCI) in diabetic patients is associated with an increased risk of restenosis and major adverse cardiac events (MACE). We assessed the impact of diabetes on long-term outcome after PCI with sirolimus-eluting (SES) and paclitaxel-eluting (PES) stents. METHODS AND RESULTS: In the SIRTAX trial, 1012 patients were randomized to treatment with SES (n = 503) or PES (n = 509). A stratified analysis of outcomes was performed according to the presence or absence of diabetes. Baseline characteristics were well balanced between SES and PES in patients with (N = 201) and without diabetes (N = 811). Clinical outcome was worse in diabetic compared with non-diabetic patients regarding death (9.0% vs. 4.1%, P = 0.004) and MACE (defined as cardiac death, myocardial infarction, or TLR; 19.9% vs. 12.7%, P = 0.007) at 2 years. Among diabetic patients, SES reduced MACE by 47% (14.8% vs. 25.8%, HR = 0.52, P = 0.05) and TLR by 61% (7.4% vs. 17.2%, HR = 0.39, P = 0.03) compared with PES at 2 years. CONCLUSION: Diabetic patients have worse prognosis than non-diabetic patients undergoing PCI with DES. Among the diabetic patient population of this trial, SES reduce repeat revascularization procedures and MACE more effectively than PES and to a similar degree as in non-diabetic patients.

Sirolimus-eluting and paclitaxel-eluting stents for coronary revascularization.

BACKGROUND: Sirolimus-eluting stents and paclitaxel-eluting stents, as compared with bare-metal stents, reduce the risk of restenosis. It is unclear whether there are differences in safety and efficacy between the two types of drug-eluting stents. METHODS: We conducted a randomized, controlled, single-blind trial comparing sirolimus-eluting stents with paclitaxel-eluting stents in 1012 patients undergoing percutaneous coronary intervention. The primary end point was a composite of major adverse cardiac events (death from cardiac causes, myocardial infarction, and ischemia-driven revascularization of the target lesion) by nine months. Follow-up angiography was completed in 540 of 1012 patients (53.4 percent). RESULTS: The two groups had similar baseline clinical and angiographic characteristics. The rate of major adverse cardiac events at nine months was 6.2 percent in the sirolimus-stent group and 10.8 percent in the paclitaxel-stent group (hazard ratio, 0.56; 95 percent confidence interval, 0.36 to 0.86; P=0.009). The difference was driven by a lower rate of target-lesion revascularization in the sirolimus-stent group than in the paclitaxel-stent group (4.8 percent vs. 8.3 percent; hazard ratio, 0.56; 95 percent confidence interval, 0.34 to 0.93; P=0.03). Rates of death from cardiac causes were 0.6 percent in the sirolimus-stent group and 1.6 percent in the paclitaxel-stent group (P=0.15); the rates of myocardial infarction were 2.8 percent and 3.5 percent, respectively (P=0.49); and the rates of angiographic restenosis were 6.6 percent and 11.7 percent, respectively (P=0.02). CONCLUSIONS: As compared with paclitaxel-eluting stents, the use of sirolimus-eluting stents results in fewer major adverse cardiac events, primarily by decreasing the rates of clinical and angiographic restenosis.

Stent thrombosis following bare-metal stent implantation: success of emergency percutaneous coronary intervention and predictors of adverse outcome.

AIMS: To investigate the efficacy and outcome of emergency percutaneous coronary interventions (PCI) in patients with stent thrombosis. METHODS AND RESULTS: Between 1995 and 2003, 6058 patients underwent bare-metal stent implantation, of which 95 (1.6%) patients suffered from stent thrombosis. The timing of stent thrombosis was acute in 10 (11%), subacute in 61 (64%), and late in 24 (25%) patients. Procedural and clinical outcomes of emergency PCI for treatment of stent thrombosis were investigated. Emergency PCI was successful in 86 (91%), complicated by death in 2 (2%), and coronary artery bypass grafting in 2 (2%) patients. Myocardial infarction occurred in 77 (81%) patients with a peak creatine kinase level of 1466+/-1570 U/L. Left ventricular ejection fraction declined from 0.54+/-0.19 prior to 0.48+/-0.16 (P<0.05) at the time of stent thrombosis after emergency PCI. A 6 month major adverse clinical events comprised death (11%), reinfarction (16%), and recurrent stent thrombosis (12%) after emergency PCI. Multivariable logistic regression analysis identified the achievement of TIMI 3 flow (OR=0.1, CI 95% 0.01-0.54, P<0.001) and diameter stenosis <50% (OR=0.06, CI 95% 0.01-0.32, P<0.001) during emergency PCI to be independently associated with a reduced risk of cardiac death. Recurrent stent thrombosis was independently predicted by the omission of abciximab (OR=4.3, CI 95% 1.1-17.5). CONCLUSION: Emergency PCI for treatment of stent thrombosis effectively restores vessel patency and flow. Patients presenting with stent thrombosis are at risk for recurrent myocardial infarction and recurrent stent thrombosis.

Losartan but not enalaprilat acutely reduces reperfusion ventricular tachyarrhythmias in hypertrophied rat hearts after low-flow ischaemia.

Based on clinical and experimental studies, angiotensin II receptor blockers and angiotensin converting enzyme inhibitors have been proposed to exert acute anti-arrhythmic effects in heart failure patients. Therefore, the goal of this study was to assess acute anti-arrhythmic effects of losartan and enalaprilat in hypertrophied rat hearts during low-flow ischaemia and reperfusion. In dose-finding experiments in non-hypertrophied isolated perfused hearts, we performed dose-response curves of losartan and enalaprilat studying monophasic action potential duration at 90% repolarisation (MAPD(90%)) and ventricular fibrillation (VF) threshold. Subsequently, we determined the effects of losartan and enalaprilat (in therapeutically relevant concentrations) on ventricular tachyarrhythmias induced by low-flow ischaemia/reperfusion in hearts demonstrating left ventricular (LV) hypertrophy 70 days after aortic banding. We found that neither drug significantly affected MAPD(90%) (1 nM-1 mM) or VF threshold (1 microM losartan and 10 microM enalaprilat) in non-hypertrophied hearts. Similarly in hypertrophied hearts, neither drug significantly affected the incidence or the duration of ventricular tachyarrhythmias (ventricular tachycardia and VF) during low-flow ischaemia. However, 1 microM losartan significantly reduced the duration of ventricular tachyarrhythmias during reperfusion. In conclusion, neither losartan nor enalaprilat is acutely anti-arrhythmic in hypertrophied rat hearts during low-flow ischaemia. During reperfusion, however, losartan but not enalaprilat exerts acute anti-arrhythmic effects.

H(2)O(2) regulates cardiac myocyte phenotype via concentration-dependent activation of distinct kinase pathways.

Reactive oxygen species (ROS) can act as signaling molecules to stimulate either hypertrophy or apoptosis in cardiac myocytes. We tested the hypothesis that the phenotypic effects of ROS are due to differential, concentration-dependent activation of specific kinase signaling pathways. Adult rat ventricular myocytes were exposed to H(2)O(2) over a broad concentration range (10-1000 microM). Low concentrations of H(2)O(2) (10-30 microM) increased protein synthesis without affecting survival. Higher concentrations of H(2)O(2) (100-200 microM) increased apoptosis (assessed by TUNEL). Still higher concentrations of H(2)O(2) (300-1000 microM) caused both apoptosis and necrosis. A hypertrophic concentration of H(2)O(2) (10 microM) increased the activity of ERK1/2, but not that of JNK, p38 kinase or Akt. An apoptotic concentration of H(2)O(2) (100 microM) activated JNK, p38 kinase and Akt, and further activated ERK1/2. The MEK1/2 inhibitor U0126 prevented the hypertrophic effect of 10 microM H(2)O(2). The apoptotic effect of 100 microM H(2)O(2) was inhibited bya dominant-negative JNK adenovirus, and was potentiated by U0126 or an Akt inhibitor. Thus, the concentration-dependent effects of ROS on myocyte hypertrophy and growth are due, at least in part, to the differential activation of specific kinase signaling pathways that regulate hypertrophy and apoptosis.

Beta-adrenergic receptor-stimulated apoptosis in cardiac myocytes is mediated by reactive oxygen species/c-Jun NH2-terminal kinase-dependent activation of the mitochondrial pathway.

Stimulation of beta-adrenergic receptors (betaARs) causes apoptosis in adult rat ventricular myocytes (ARVMs). The role of reactive oxygen species (ROS) in mediating betaAR-stimulated apoptosis is not known. Stimulation of betaARs with norepinephrine (10 micromol/L) in the presence of prazosin (100 nmol/L) for 24 hours increased the number of apoptotic myocytes as determined by TUNEL staining by 3.6- fold. The superoxide dismutase/catalase mimetics Mn(III)tetrakis(1-methyl-4-pyridyl)porphyrin pentachloride (MnTMPyP; 10 micromol/L) and Euk-134 decreased betaAR-stimulated apoptosis by 89+/-6% and 76+/-10%, respectively. Infection with an adenovirus expressing catalase decreased betaAR-stimulated apoptosis by 82+/-15%. The mitochondrial permeability transition pore inhibitor bongkrekic acid (50 micromol/L) decreased betaAR-stimulated apoptosis by 76+/-8%, and the caspase inhibitor zVAD-fmk (25 micromol/L) decreased betaAR-stimulated apoptosis by 62+/-11%. betaAR-stimulated cytochrome c release was inhibited by MnTMPyP. betaAR stimulation caused c-Jun NH2-terminal kinase (JNK) activation, which was abolished by MnTMPyP. Transfection with an adenovirus expressing dominant-negative JNK inhibited betaAR-stimulated apoptosis by 81+/-12%, and the JNK inhibitor SP600125 inhibited both betaAR-stimulated apoptosis and cytochrome c release. Thus, betaAR-stimulated apoptosis in ARVMs involves ROS/JNK-dependent activation of the mitochondrial death pathway.

Reciprocal modulation of mitogen-activated protein kinases and mitogen-activated protein kinase phosphatase 1 and 2 in failing human myocardium.

BACKGROUND: Mitogen-activated protein kinases (MAPKs), consisting of the ERK1/2, JNKs, and p38-kinase families, play a key role in the regulation of myocyte growth and apoptosis in vitro. The activity of MAPKs is regulated by dual-specificity MAPK phosphatases (MKPs). Because myocardial failure is associated with myocyte hypertrophy and apoptosis, MAPKs may play a pathophysiologic role in human myocardial failure. METHODS AND RESULTS: We measured MAPKs activities and the protein levels of MAPKs and MKPs (MKP-1 and MKP-2) in the myocardium explanted at the time of transplantation from patients with end-stage failure caused by idiopathic dilated cardiomyopathy (n = 5-7). Nonfailing donor hearts (n = 5-7) were used for comparison. Although the protein levels for JNK1/2 and p38-kinase in failing hearts were not different from levels in nonfailing hearts, the activities of both were decreased (P <.05). Despite a >3-fold increase in the protein level for ERK1/2 in failing hearts, ERK1/2 activity was not increased. Expression of MKP-2 was significantly increased in failing hearts, while expression of MKP-1 was increased in 5 of 7 failing hearts as measured by Western analysis. CONCLUSIONS: JNK1/2 and p38 activities are decreased in failing human myocardium. Increased expression of MKPs may therefore contribute to decreased MAPKs activity in failing human myocardium.