Transvenous lead extraction (TLE) is a complex invasive procedure and the experience of the operator and the team is a major determinant of procedural outcomes. Because of very limited data available on minimum procedural volumes to enable training and ongoing competency for TLEs, we performed a meta-analysis aimed at assessing the outcomes of TLE in the centres with low, medium, and high volume of procedures. Of the 280 papers initially retrieved until February 2013, 66 observational studies met inclusion criteria and were included in at least one stratified meta-analysis: 17 were prospective studies; 47 had a retrospective design; and 2 were defined ‘experience studies’. We included only articles published after the introduction of laser technique (year 1999). We divided the studies in low, medium, and high volume centres utilizing either the European Heart Rhythm Association (EHRA) or Lexicon classification criteria. When meta-analyses were carried out separately for the studies with larger and smaller sample sizes, either using EHRA or Lexicon classification criteria, no clear differences emerged in the combined rate of major complications or intraoperative deaths. In contrast, both minor complications and mortality at 30 days decreased as centre volume increased. In our meta-analysis of observational studies, patients who have been treated in higher volume centres have a lower probability of minor complications and death at 30 days regardless of the infection rate, length of lead duration, type of device, and type of extraction.

Objective: Recent data suggest that vagus nerve stimulation (VNS) can inhibit cytokine release by inflammatory cells. Accordingly, an association between impaired cardiac parasympathetic function, as assessed by heart rate variability (HRV), and increased markers of inflammation has recently been reported. In this study we assessed the effect of direct left VNS on inflammatory markers and HRV in patients with refractory epilepsy. Methods: A 24-hour electrocardiogram Holter recording was performed both at baseline and after 3 months of left VNS in 8 patients (age 32 ± 24 years, 2 men) who underwent implantation of a VNS device because of refractory epilepsy. Tumor necrosis factor-α, interleukin-6 and C-reactive protein serum levels were measured, as markers of inflammation, at the same times. Results: No significant changes were found after 3 months of left VNS, compared to baseline, both for HRV variables and inflammatory markers. Also, no consistent correlation could be demonstrated between HRV parameters and inflammatory markers in these patients. Conclusions: Our data in epileptic patients without cardiovascular disease failed to show a significant effect of left VNS on cardiac autonomic function and on systemic inflammation at short-term follow-up.

A great deal of evidence has revealed an important link between gut microbiota and the heart. In particular, the gut microbiota plays a key role in the onset of cardiovascular (CV) disease, including heart failure (HF). In HF, splanchnic hypoperfusion causes intestinal ischemia resulting in the translocation of bacteria and their metabolites into the blood circulation. Among these metabolites, the most important is Trimethylamine N-Oxide (TMAO), which is responsible, through various mechanisms, for pathological processes in different organs and tissues. In this review, we summarise the complex interaction between gut microbiota and CV disease, particularly with respect to HF, and the possible strategies for influencing its composition and function. Finally, we highlight the potential role of TMAO as a novel prognostic marker and a new therapeutic target for HF.

Objectives: The aim of our study was to assess the prognostic value of heart rate variability (HRV) in ST-segment elevation acute myocardial infarction (STEMI) patients treated by percutaneous transluminal coronary angioplasty (PTCA) and optimal medical therapy. Methods: We enrolled 182 consecutive patients with a first STEMI (59.1 ± 11 years; 82.4% men) treated by primary PTCA. HRV was assessed on 24-hour Holter ECG recordings before discharge and 1 and 6 months after discharge. The primary end point was the occurrence of major clinical events (MCE), defined as death or new acute myocardial infarction (AMI). Results: At a follow-up of 42 ± 23 months, MCE occurred in 14 patients (7.6%; 3 deaths and 11 re-AMIs). HRV parameters before discharge were significantly lower in patients with MCE, with standard deviation of all RR intervals (SDNN) and very low frequency and low frequency (LF) amplitude being the most predictive variables. HRV assessed at follow-up instead did not significantly predict MCE. At multivariate analysis, only SDNN (HR 0.97; p = 0.02) and LF (HR 0.90; p = 0.04) remained significantly associated with MCE. Lower tertile SDNN and LF values were associated with a multivariate HR of 3.91 (p = 0.015) and of 2.92 (p = 0.048), respectively. Similar results were observed considering re-AMI only as the end point. Conclusions: In STEMI patients treated by PTCA, HRV assessed before discharge was an independent predictor of MCE and re-AMI.

Lanza GA, Barone L, Scalone G, Pitocco D, Sgueglia GA, Mollo R, Nerla R, Zaccardi F, Ghirlanda G, Crea F (Istituto di Cardiologia; and Università Cattolica del Sacro Cuore, Roma; Italy). Inflammation‐related effects of adjuvant influenza A vaccination on platelet activation and cardiac autonomic function. J Intern Med 2010; 269: 118–125. Background. Inflammation, platelet reactivity and cardiac autonomic dysfunction increase the risk of cardiovascular events, but the relationships between these prognostic markers are poorly defined. In this study, we investigated the effect of an inflammatory stimulus (influenza A vaccine) on platelet activation and cardiac autonomic function. Methods. We measured serum C‐reactive protein (CRP) and interleukin‐6 levels, monocyte–platelet aggregates (MPAs) and monocyte/platelet receptor expression before and after adjuvant influenza A vaccination in 28 patients with type II diabetes (mean age 62.1 ± 8 years, 18 men). Twenty‐four‐hour Holter electrocardiogram was recorded 24 h before and after vaccination; heart rate variability (HRV) was assessed as a measure of cardiac autonomic function. Results. Inflammatory cytokines, MPA formation and monocyte/platelet receptor expression increased after vaccination. CRP was 2.6 ± 2.8 and 7.1 ± 5.7 mg L⁻¹ 48 h before and after vaccination, respectively (P < 0.0001). HRV parameters decreased after vaccination compared to baseline, with very low‐frequency amplitude showing the most significant change (34.6 ± 11.8 and 31.0 ± 10.2 ms 48 h before and after vaccination, respectively; P = 0.002). A significant correlation was found between percentage changes in CRP levels and in most HRV variables, with the most significant correlations between changes in CRP levels and changes in standard deviation of all normal RR intervals (r = 0.43; P = 0.02). Conclusions. Together with an inflammatory reaction, influenza A vaccine induced platelet activation and sympathovagal imbalance towards adrenergic predominance. Significant correlations were found between CRP levels and HRV parameters, suggesting a pathophysiological link between inflammation and cardiac autonomic regulation. The vaccine‐related platelet activation and cardiac autonomic dysfunction may transiently increase the risk of cardiovascular events.