Voltage and propagation mapping: New tools to improve successful ablation of atrioventricular nodal reentry tachycardia.

INTRODUCTION: Mapping system is useful in ablation of atrioventricular nodal reentry tachycardia (AVNRT) and localization of anatomic variances. Voltage mapping identifies a low voltage area in the Koch triangle called low-voltage-bridge (LVB); propagation mapping identifies the collision point (CP) of atrial wavefront convergence. We conducted a prospective study to evaluate the relationship between LVB and CP with successful site of ablation and identify standard value for LVB. MATERIALS AND METHODS: Three-dimensional (3D) maps of the right atria were constructed from intracardiac recordings using the ablation catheter. Cut-off values on voltage map were adjusted until LVB was observed. On propagation map, atrial wavefronts during sinus rhythm collide in the site representing CP, indicating the area of slow pathway conduction. Ablation site was selected targeting LVB and CP site, confirmed by anatomic position on fluoroscopy and atrioventricular ratio. RESULTS: Twenty-seven consecutive patients were included. LVB and CP were present in all patients. Postprocedural evaluation identified standard cut-off of 0.3-1 mV useful for LVB identification. An overlap between LVB and CP was observed in 23 (85%) patients. Procedure success was achieved in all patient with effective site at first application in 22 (81%) patients. There was a significant correlation between LVB, CP, and the site of effective ablation (p = .001). CONCLUSION: We found correlation between LVB and CP with the site of effective ablation, identifying a voltage range useful for standardized LVB identification. These techniques could be useful to identify ablation site and minimize radiation exposure.

Drug-eluting compared to bare metal stents in patients with end-stage renal disease on dialysis: a meta-analysis.

AIMS: To systematically review literature comparing bare metal stent (BMS) to drug-eluting stent (DES) in end-stage renal disease (ESRD) patients on dialysis. ESRD patients on dialysis often suffer from accelerated atherosclerosis and higher rate of stent-related complications including major adverse cardiovascular events. Because dialysis usually qualifies ineligibility for randomized clinical trials, an evidenced-based stent choice for these patients is scarce. METHODS: PUBMED, CINHAL, COCHRANE, EMBASE and WEB OF SCIENCE were searched for studies comparing BMS vs. DES outcome in ESRD patients on dialysis. RESULTS: Twenty studies including 64 232 patients were considered. The use of DES was significantly associated with a reduction in all-cause mortality [odds ratio (OR) 0.83, 95% confidence interval (CI) 0.76-0.89], death from a cardiovascular cause (OR 0.80, 95% CI 0.76-0.84) and target lesion revascularization/target vessel revascularization (OR 0.73, 95% CI 0.53-1.00). No significant difference was found in stent thrombosis (OR 1.08, 95% CI 0.50-2.33) and myocardial infarction incidence (OR 0.91, 95% CI 0.69-1.20). CONCLUSIONS: Our meta-analysis shows a significant reduction in all-cause and cardiovascular mortality with the use of DES over BMS in dialyzed patients. Despite the lack of randomized studies, systematic use of DES in these high-risk patients should thus reasonably be considered as a first option in percutaneous coronary intervention candidates.

Drug eluting stents are superior to bare metal stents to reduce clinical outcome and stent-related complications in CKD patients, a systematic review, meta-analysis and network meta-analysis.

Aims To compare clinical outcome in Chronic kidney disease (CKD) patients receiving coronary stents according to stent type BMS versus DES and 1st generation versus 2nd generation DES. Methods and Results PubMed, Cinhal, Cochrane, Embase, and Web of Science were searched for studies including CKD patients. CKD was defined as eGFR < 60 mL/min. We selected n = 35 articles leading to 376 169 patients, of which 76 557 CKD patients receiving BMS n = 35,807, 1st generation DES n = 37,650, or 2nd generation DES n = 3100. Patient receiving DES, compared to BMS, had a 18% lower all-cause mortality (RR 0.82, 95%CI 0.71-0.94). The composite of death or myocardial infarction (MI) was lower in DES patients (RR 0.78, 95%CI 0.67-0.91), as was stent thrombosis (ST) (RR 0.57, 95%CI 0.34-0.95), target vessel/lesion revascularization (TVR/TLR) (RR 0.69, 95%CI 0.57-0.84) and death for cardiovascular cause (RR 0.43, 95%CI 0.25-0.74). We also found a gradient between 1st and 2nd generation DES, through BMS. Second, compared to 1st generation DES, were associated with further relative risk (RR) reduction of -18% in of all-cause death, and lower incidence of stent-related clinical events: -39% RR of ST risk; -27 RR of TVR/TLR risk. Conclusions DES in CKD patients undergoing PCI were superior to BMS in reducing major adverse clinical events. This was possibly explained, by a lower risk of stent-related events as ST and TVR or TLR. Second, compared to 1st generation DES may furtherly reduce clinical events.

Infections, immunity and atherosclerosis: pathogenic mechanisms and unsolved questions.

The role of inflammation and immunity in the pathogenesis and clinical manifestations of atherosclerotic disease has been widely studied. Common infectious diseases can be associated with a chronic inflammatory state which is the hallmark of atherosclerosis, thus suggesting a possible link between the two pathological conditions. Therefore, a great number of studies have tested the "infection hypothesis", but their results are conflicting. Nevertheless, several molecular and biological mechanisms possibly involved in the complex relationship between infections, immune response, vascular wall damage and atherosclerosis onset and progression have been described. The purpose of this article is to offer an overview of the principal mechanisms and molecular pathways that probably constitute the most relevant biological substrate on which the infection hypothesis is founded; some of these mechanisms are not fully understood yet. Nevertheless, their comprehension could be essential for the development of new preventive and therapeutic strategies.