Arrhythmic Mitral Valve Prolapse and Sports Activity: Pathophysiology, Risk Stratification, and Sports Eligibility Assessment.

Although mitral valve prolapse (MVP) is the most prevalent valvular abnormality in Western countries and generally carries a good prognosis, a small subset of patients is exposed to a significant risk of malignant ventricular arrhythmias (VAs) and sudden cardiac death (SCD), the so-called arrhythmic MVP (AMVP) syndrome. Recent work has emphasized phenotypical risk features of severe AMVP and clarified its pathophysiology. However, the appropriate assessment and risk stratification of patients with suspected AMVP remains a clinical conundrum, with the possibility of both overestimating and underestimating the risk of malignant VAs, with the inappropriate use of advanced imaging and invasive electrophysiology study on one hand, and the catastrophic occurrence of SCD on the other. Furthermore, the sports eligibility assessment of athletes with AMVP remains ill defined, especially in the grey zone of intermediate arrhythmic risk. The definition, epidemiology, pathophysiology, risk stratification, and treatment of AMVP are covered in the present review. Considering recent guidelines and expert consensus statements, we propose a comprehensive pathway to facilitate appropriate counseling concerning the practice of competitive/leisure-time sports, envisioning shared decision making and the multidisciplinary "sports heart team" evaluation of borderline cases. Our final aim is to encourage an active lifestyle without compromising patients' safety.

Detect Long-term Complications After ICD Replacement (DECODE): Rationale and Study Design of a Multicenter Italian Registry.

The replacement of implantable cardioverter-defibrillators (ICDs) may give rise to considerable clinical consequences, the importance of which is underrated by the medical community. Replacement-related adverse events are difficult to identify and require monitoring of both short-term complications and long-term patient outcome. The aim of this study is to perform a structured evaluation of both short- and long-term adverse events and a cost analysis of consecutive ICD replacement procedures. Detect Long-term Complications After ICD Replacement (DECODE) is a prospective, single-arm, multicenter cohort study designed to estimate long-term complication rates (at 12 months and 5 years) in patients undergoing ICD generator replacement. The study will also evaluate predictors of complications, patient management before and during the replacement procedure in clinical practice, and the costs related to use of health care resources. About 800 consecutive patients with standard indications for ICD generator replacement will be enrolled in this study. The decision to undertake generator replacement/upgrade will be made according to the investigators' own judgment (which will be recorded). Patients will be followed for 60 months through periodic in-hospital examinations or remote monitoring. Detailed data on complications related to ICD replacement in current clinical practice are still lacking. The analysis of adverse events will reveal the value of new preventive strategies, thereby yielding both clinical and economic benefits. Moreover, assessment of complication rates after ICD replacement in a real-life setting will help estimate the actual long-term cost of ICD therapy and assess the real impact of increasing ICD longevity on cost-effectiveness.

Improved implant and postoperative lead performance in CRT-D patients implanted with a quadripolar left ventricular lead. A 6-month follow-up analysis from a multicenter prospective comparative study.

PURPOSE: Small single-center comparative studies suggest improved outcomes in cardiac resynchronization therapy (CRT) patients implanted with a quadripolar left ventricular (LV) lead in comparison with non-quadripolar (bipolar) leads. This study represents the first large multicenter prospective registry comparing implant and 6-month postoperative lead performance following CRT-defibrillator (CRT-D) implantation with quadripolar vs. bipolar leads. METHODS: During a 39-month period, 418 consecutive patients having CRT-D implantation attempts with either a quadripolar (n = 230) or bipolar LV lead (n = 188) were enrolled in the registry. The primary outcome of the study was LV lead failure defined as any abnormality, excluding infection, resulting in surgical lead revision or CRT termination. Additionally, operative and follow-up data were analyzed for significant difference between groups. RESULTS: Baseline characteristics of both groups were similar. In 72.9 % of quadripolar leads versus 65.0 % of bipolar leads, the LV lead successfully engaged the predefined ideal target side branch (p = 0.47). Implant duration and fluoroscopy times were significantly shorter when a quadripolar lead was used (p = 0.007 and p = 0.001, respectively). The primary end point occurred in six patients (2.7 %) in the quadripolar group and in 14 patients (8.0 %) in the bipolar group (p = 0.02). Clinically significant phrenic nerve stimulation (PNS) occurred in 4.6 vs. 14.2 % of quadripolar vs. bipolar patients, respectively (p = 0.002); all PNS were resolved noninvasively through programming in the quadripolar group vs. 84 % in bipolar group (p = 0.75). The use of a bipolar lead was associated with a higher risk of surgical LV lead revision (6.3 vs. 2.3 %; p = 0.057) and a higher incidence of dislodgment (5.7 vs. 2.7 %; p = 0.16). CONCLUSIONS: This multicenter study demonstrates that the use of a quadripolar LV lead results in significantly lower rates of lead-related problems and reduced procedural and fluoroscopic times for biventricular system implantation. This has important implications for LV pacing lead choice.

Clinical impact of catheter ablation in patients with asymptomatic atrial fibrillation: the IRON-AF (Italian registry on NavX atrial fibrillation ablation procedures) study.

Whether and to what extent patients with asymptomatic atrial fibrillation (AF) would benefit from catheter ablation has not been investigated. This is the first multicenter prospective study reporting on the outcome of catheter ablation in patients with asymptomatic AF. Consecutive patients (n = 545) referred for AF ablation were prospectively enrolled in a multicenter Italian registry. Of these patients, 54 have asymptomatic AF and composed our patient population. At 24 month follow-up, catheter ablation in asymptomatic AF patients resulted to be as safe and effective as in patients with drug refractory symptomatic AF. Our study provides significant insights on the role of AF ablation in asymptomatic patients. Further studies in much larger cohorts are needed to validate our conclusions.

New insights into molecular mechanisms of diffuse coronary ectasiae: a possible role for VEGF.

BACKGROUND: Diffuse coronary artery ectasiae (DCE) are occasionally found at necropsy or at angiography. Pathogenetic mechanisms of DCE are still poorly known. Matrix metalloproteinases (MMPs), tissue inhibitors of MMPs (TIMPs) and vascular endothelial growth factor (VEGF) are involved in vascular remodeling and may play a role in DCE. METHODS: A total of 1280 consecutive coronary angiograms performed in a single institution in 1 year were screened. DCE were found in 15 patients. Diagnosis at hospital admission was acute coronary syndromes in all of them. Two patients died during initial admission and 1 refused blood sampling; the remaining 12 patients were enrolled in the study. No patient with DCE exhibited coronary stenoses. Plasma levels of VEGF, MMP-2, TIMP-1, TIMP-2 and C-reactive protein (CRP) were measured in these 12 patients 12 months after discharge during a silent clinical phase, in 12 age- and sex-matched patients with stable angina (SA) and coronary artery disease, and in 12 age- and sex-matched patients with normal coronary arteries (NCA). RESULTS: VEGF levels were higher in patients with DCE than in SA or NCA (151.6 pg/ml [36.2-252.9] vs. 66.6 pg/ml [36.4-93.3] and 54.8 pg/ml [14.5-87.1], respectively, p = 0.012]. TIMP-2 levels were lower in DCE and SA than in NCA (5.9 ng/ml [0-33.6] and 5.0 [0-17.4] vs. 139.3 ng/ml [114.4-237.4], respectively, p < 0.001). TIMP-1 and MMP-2 plasma levels were similar in all groups (p = NS), and CRP levels were within normal limits (< 3 mg/L) in most patients, irrespective of their coronary anatomy (75% for DCE, 66% for SA, and 84% for NCA [p = NS]). CONCLUSIONS: Symptomatic patients with DCE typically present with an acute coronary syndrome and exhibit lack of obstructive stenosis at angiography, decreased plasma levels of TIMP-2 and raised plasma levels of VEGF. The simultaneous occurrence of reduced MMPs inhibition and increased angiogenetic activity suggests an accelerated and persistent extracellular matrix remodeling process favouring arterial remodeling and aneurysms formation which is likely to enhance the risk of thrombosis because of low shear stress.

Stenting versus surgical bypass grafting for coronary artery disease: systematic overview and meta-analysis of randomized trials.

BACKGROUND: Coronary angioplasty and coronary artery bypass grafting (CABG) are both major techniques for the management of coronary artery disease, but CABG is associated with a lower incidence of repeat revascularization. Recent studies comparing angioplasty with stenting vs CABG have yielded conflicting results, with some suggesting improved survival with stenting, and others the opposite. We thus undertook a systematic overview of the randomized trials comparing stenting vs CABG in coronary artery disease. METHODS: MEDLINE (January 1986-February 2003), ISI Current Contents, the Cochrane Controlled Trial Register, LILACS and the American Heart Association, American College of Cardiology, European Society of Cardiology, and Transcatheter Cardiovascular Therapeutics conference proceedings were among the databases we searched. Abstraction was performed in a non-blinded manner on pre-specified forms. The random-effect odds ratios for death, myocardial infarction, stroke, repeat revascularization, and symptomatic angina were computed for the longest available follow-up. RESULTS: Nine randomized trials (3283 patients, representing only 6% of all screened subjects) with an average follow-up of 28 months were included in the analysis, while four studies were excluded because they were still unpublished, ongoing, or with non-systematic stenting. No study used drug-eluting stents. The odds ratios for stenting vs CABG were 0.82 (95% confidence interval-CI 0.57-1.18, p = 0.3) for the occurrence of death, non-fatal myocardial infarction or stroke, 4.6 (95% CI 3.5-5.9, p < 0.00001) for repeat revascularization, and 2.3 (95% CI 1.8-2.8, p < 0.00001) for symptomatic angina. Heterogeneity tests were not statistically significant. The results of sensitivity analysis were similar even after stratification for single vessel, off-pump, single center or high-quality studies. CONCLUSIONS: Overall and event-free survival after conventional stenting for coronary artery disease are similar to those after CABG, but surgery is still associated with a significantly lower incidence of repeat revascularization and symptoms. The role of next-generation drug-eluting stents in widening the indications for stenting and overcoming restenosis will need to be assessed in future observational and randomized studies comparing stenting vs CABG.