Catheter ablation vs. antiarrhythmic drug therapy in patients with symptomatic atrioventricular nodal re-entrant tachycardia: a randomized, controlled trial.

Aims: To conduct a randomized trial in order to guide the optimum therapy of symptomatic atrioventricular nodal re-entrant tachycardia (AVNRT). Methods and Results: Patients with at least one symptomatic episode of tachycardia per month and an electrophysiologic diagnosis of AVNRT were randomly assigned to catheter ablation or chronic antiarrhythmic drug (AAD) therapy with bisoprolol (5 mg od) and/or diltiazem (120-300 mg od). All patients were properly educated to treat subsequent tachycardia episodes with autonomic manoeuvres or a 'pill in the pocket' approach. The primary endpoint of the study was hospital admission for persistent tachycardia cardioversion, during a follow-up period of 5 years. Sixty-one patients were included in the study. In the ablation group, 1 patient was lost to follow-up, and 29 were free of arrhythmia or conduction disturbances at a 5-year follow-up. In the AAD group, three patients were lost to follow-up. Of the remainder, 10 patients (35.7%) continued with initial therapy, 11 patients (39.2%) remained on diltiazem alone, and 7 patients (25%) interrupted their therapy within the first 3 months following randomization, and subsequently developed an episode requiring cardioversion. During a follow-up of 5 years, 21 patients in the AAD group required hospital admission for cardioversion. Survival free from the study endpoint was significantly higher in the ablation group compared with the AAD group (log-rank test, P < 0.001). Conclusions: Catheter ablation is the therapy of choice for symptomatic AVNRT. Antiarrhythmic drug therapy is ineffective and not well tolerated

Flow Patterns at Stented Coronary Bifurcations Computational Fluid Dynamics Analysis

Background—The ideal bifurcation stenting technique is not established, and data on the hemodynamic characteristics at stented bifurcations are limited. Methods and Results—We used computational fluid dynamics analysis to assess hemodynamic parameters known affect the risk of restenosis and thrombosis at coronary bifurcations after the use of various single- and double-stenting techniques. We assessed the distributions and surface integrals of the time averaged wall shear stress (TAWSS), oscillatory shear index (OSI), and relative residence time (tr). Single main branch stenting without side branch balloon angioplasty or stenting provided the most favorable hemodynamic results (integrated values of TAWSS=4.13·10−4 N, OSI=7.52·10−6 m2, tr=5.57·10−4 m2/Pa) with bifurcational area subjected to OSI values >0.25, >0.35, and >0.45 calculated as 0.36 mm2, 0.04 mm2, and 0 mm2, respectively. Extended bifurcation areas subjected to these OSI values were seen after T-stenting: 0.61 mm2, 0.18 mm2, and 0.02 mm2, respectively. Among the considered double-stenting techniques, crush stenting (integrated values of TAWSS=1.18·10−4 N, OSI=7.75·10−6 m2, tr=6.16·10−4 m2/Pa) gave the most favorable results compared with T-stenting (TAWSS=0.78·10−4 N, OSI=10.40·10−6 m2, tr=6.87·10−4 m2/Pa) or the culotte technique (TAWSS=1.30· 10−4 N, OSI=9.87·10−6 m2, tr=8.78·10−4 m2/Pa). Conclusions—In the studied models of computer simulations, stenting of the main branch with our without balloon angioplasty of the side branch offers hemodynamic advantages over double stenting. When double stenting is considered, the crush technique with the use of a thin-strut stent may result in improved immediate hemodynamics compared with culotte or T-stenting

Remote magnetic versus manual catheters: evaluation of ablation effect in atrial fibrillation by myocardial marker levels

Background A remote magnetic navigation (MN) system is available for radiofrequency ablation of atrial fibrillation (AF), challenging the conventional manual ablation technique. The myocardial markers were measured to compare the effects of the two types of MN catheters with those of a manual-irrigated catheter in AF ablation. Methods AF patients underwent an ablation procedure using either a conventional manual-irrigated catheter (CIR, n=65) or an MN system utilizing either an irrigated (RMI, n=23) or non-irrigated catheter (RMN, n=26). Levels of troponin T (TnT) and the cardiac isoform of creatin kinase (CKMB) were measured before and after ablation. Results Mean procedure times and total ablation times were longer employing the remote magnetic system. In all groups, there were pronounced increases in markers of myocardial injury after ablation, demonstrating a significant correlation between total ablation time and post-ablation levels of TnT and CKMB (CIR r=0.61 and 0.53, p<0.001; RMI r=0.74 and 0.73, p<0.001; and RMN r=0.51 and 0.59, p<0.01). Time-corrected release of TnT was significantly higher in the CIR group than in the other groups. Of the patients, 59.6% were free from AF at follow-up (12.2± 5.4 months) and there were no differences in success rate between the three groups. Conclusions Remote magnetic catheters may create more discrete and predictable ablation lesions measured by myocardial enzymes and may require longer total ablation time to reach the procedural endpoints. Remote magnetic non-irrigated catheters do not appear to be inferior to magnetic irrigated catheters in terms of myocardial enzyme release and clinical outcome

Detection of silent myocardial ischemia in asymptomatic patients with diabetes: results of a randomized trial and meta-analysis assessing the effectiveness of systematic screening

<p>Abstract</p> <p>Background</p> <p>Most guidelines recommend a systematic screening of asymptomatic high risk patients with diabetes for silent ischemia, but the clinical benefit of this strategy has not been demonstrated compared with the simple control of cardiovascular risk factors. We sought to determine whether referring asymptomatic diabetic patients for screening of silent ischemia decreases the risk of cardiovascular events compared with usual care.</p> <p>Methods</p> <p>DYNAMIT was a prospective, randomized, open, blinded end-point multicenter trial run between 2000 and 2005, with a 3.5 year mean follow-up in ambulatory care in 45 French hospitals. The study included 631 male and female with diabetes aged 63.9 ± 5.1 years, with no evidence of coronary artery disease and at least 2 additional cardiovascular risk factors, receiving appropriate medical treatment. The patients were randomized centrally to either screening for silent ischemia using a bicycle exercise test or Dipyridamole Single Photon Emission Computed Tomography (N = 316), or follow-up without screening (N = 315). The main study end point was time to death from all causes, non-fatal myocardial infarction, non-fatal stroke, or heart failure requiring hospitalization or emergency service intervention. The results of a meta-analysis of DYNAMIT and DIAD, a similar study, are also presented.</p> <p>Results</p> <p>The study was discontinued prematurely because of difficulties in recruitment and a lower-than expected event rate. Follow-up was complete for 98.9% patients regarding mortality and for 97.5% regarding the main study end point. Silent ischemia detection procedure was positive or uncertain in 68 (21.5%) patients of the screening group. There was no significant difference between the screening and the usual care group for the main outcome (hazard ratio = 1.00 95%CI 0.59 to 1.71). The meta-analysis of these and DIAD results gave similar results, with narrower confidence intervals for each endpoint.</p> <p>Conclusions</p> <p>These results suggest that the systematic detection of silent ischemia in high-risk asymptomatic patients with diabetes is unlikely to provide any major benefit on hard outcomes in patients whose cardiovascular risk is controlled by an optimal medical treatment.</p> <p>Trial registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00627783">NCT00627783</a></p

MicroRNAs as Biomarkers for Myocardial Infarction

MicroRNAs (miRs) are short non-coding RNA molecules involved in post-transcriptional gene regulation by binding to the 3′ untranslated region of a messenger RNA (mRNA), thereby inhibiting the translation or inducing mRNA destabilization. MiRs are generally considered to act as intracellular mediators essential for normal cardiac function, and their deregulated expression profiles have been associated with cardiovascular diseases. Recent studies have revealed the existence of freely circulating miRs in human peripheral blood, which are present in a stable nature. This has raised the possibility that miRs may be released in the circulation and can serve as novel diagnostic markers for acute or chronic human disorders, including myocardial infarction (MI). This review summarizes the recent findings of miRs that fulfill the criteria of candidate biomarkers for MI