Nikolaos Dagres

Influence of the duration of Holter monitoring on the detection of arrhythmia recurrences after catheter ablation of atrial fibrillation: Implications for patient follow-up

We investigated the influence of Holter duration on the detection of recurrences after ablation for atrial fibrillation (AF). Two-hundred-and-fifteen patients underwent a 7-day Holter ECG at 6 months after catheter ablation. We analyzed the number of patients who had a recurrence within the first 24, 48, 72 h etc. up to the total of 7 days. During the complete 7-day recording, 30% had a recurrence. All Holter durations ≤5 days would have detected significantly less patients with recurrence than the complete 7-day recording. A 24-hour Holter would have detected 59%, a 48-hour Holter 67% and a 72-hour Holter 80% of patients with recurrences, whereas a 4-day recording would have detected 91% of the recurrences that were detected with the complete 7-day recording. In conclusion, a Holter duration of less than 4 days misses a great portion of recurrences, whereas a 4-day recording might offer a reasonable compromise.

Steerable Versus Nonsteerable Sheath Technology in Atrial Fibrillation Ablation A Prospective, Randomized Study

Background— Steerable sheath technology is designed to facilitate catheter access, stability, and tissue contact in target sites of atrial fibrillation (AF) catheter ablation. We hypothesized that rhythm control after interventional AF treatment is more successful using a steerable as compared with a nonsteerable sheath access. Methods and Results— One hundred thirty patients with paroxysmal or persistent drug-refractory AF undergoing their first ablation procedure were prospectively included in a randomized fashion in 2 centers. Ablation was performed by 10 operators with different levels of clinical experience. Treatment outcome was measured with serial 7-day Holter ECGs and additional symptom-based arrhythmia documentation. Single procedure success (freedom from AF and/or atrial macroreentrant tachycardia) was significantly higher in patients ablated with a steerable sheath (78% versus 55% after 3 months, P=0.005; 76% versus 53% after 6 months, P=0.008). Rate of pulmonary vein isolation, procedure duration, and radiofrequency application time did not differ significantly, whereas fluoroscopy time was lower in the steerable sheath group (33±14 minutes versus 45±17 minutes, P<0.001). Complication rates showed no significant difference (3.2% versus 5%, P=0.608). On multivariable analysis, steerable sheath usage remained the only powerful predictor for rhythm outcome after 6 months of follow-up (hazard ratio, 2.837 [1.197 to 6.723]). Conclusions— AF catheter ablation using a manually controlled, steerable sheath for catheter navigation resulted in a significantly higher clinical success rate, with comparable complication rates and with a reduction in periprocedural fluoroscopy time. Clinical Trial Registration— URL: http://clinicaltrials.gov. Unique identifier: NCT00469638.

Risk stratification after myocardial infarction: is left ventricular ejection fraction enough to prevent sudden cardiac death?

Patients who have experienced a myocardial infarction (MI) are at increased risk of sudden cardiac death (SCD). With the advent of implantable cardioverter-defibrillators (ICDs), accurate risk stratification has become very relevant. Numerous investigations have proven that a reduced left ventricular ejection fraction (LVEF) significantly increases the SCD risk. Furthermore, ICD implantation in patients with reduced LVEF confers significant survival benefit. As a result, LVEF is the cornerstone of current decision making for prophylactic ICD implantation after MI. However, LVEF as standalone risk stratifier has major limitations: (i) the majority of SCD cases occur in patients with preserved or moderately reduced LVEF, (ii) only relatively few patients with reduced LVEF will benefit from an ICD (most will never experience a threatening arrhythmic event, others have a high risk for non-sudden death), (iii) a reduced LVEF is a risk factor for both sudden and non-sudden death. Several other non-invasive and invasive risk stratifiers, such as ventricular ectopy, QRS duration, signal-averaged electrocardiogram, microvolt T-wave alternans, markers of autonomic tone as well as programmed ventricular stimulation, have been evaluated. However, none of these techniques has unequivocally demonstrated the efficacy when applied alone or in combination with LVEF. Apart from their limited sensitivity, most of them are risk factors for both sudden and non-sudden death. Considering the multiple mechanisms involved in SCD, it seems unlikely that a single test will prove adequate for all patients. A combination of clinical characteristics with selected stratification tools may significantly improve risk stratification in the future.

Changes in QRS voltage in cardiac tamponade and pericardial effusion: reversibility after pericardiocentesis and after anti-inflammatory drug treatment

OBJECTIVES The goal of this study was to define the association between low QRS voltage and cardiac tamponade or pericardial effusion and to assess the reversibility of low QRS voltage after therapeutic procedures. BACKGROUND It is unclear whether low QRS voltage is a sign of cardiac tamponade or whether it is a sign of pericardial effusion per se. METHODS In a prospective study design, we recorded consecutive 12-lead electrocardiograms and echocardiograms in 43 patients who were referred to our institution for evaluation and therapy of a significant pericardial effusion. Cardiac tamponade was present in 23 patients (53%). Low QRS voltage (defined as maximum QRS amplitude <0.5 mV in the limb leads) was found in 14 of these 23 subjects (61%). Nine of these 14 patients were treated by pericardiocentesis (group A). Five patients received anti-inflammatory medication (group B). Group C consisted of nine patients with pericarditis and significant pericardial effusion who had no clinical evidence of tamponade. RESULTS In group A, low QRS voltage remained largely unchanged immediately after successful pericardiocentesis (0.36 +/- 0.17 mV before vs. 0.42 +/- 0.21 mV after, p = NS), but QRS amplitude recovered within a week (0.78 +/- 0.33 mV, p < 0.001). In group B, the maximum QRS amplitude increased from 0.40 +/- 0.20 mV to 0.80 +/- 0.36 mV (p < 0.001) within six days. In group C, all patients had a normal QRS amplitude initially (1.09 +/- 0.55 mV) and during a seven-day follow-up (1.10 +/- 0.56 mV, p = NS). CONCLUSIONS Low QRS voltage is a feature of cardiac tamponade but not of pericardial effusion per se. Our findings indicate that the presence and severity of cardiac tamponade, in addition to inflammatory mechanisms, may contribute to the development of low QRS voltage in patients with large pericardial effusions.

Significant gender-related differences in radiofrequency catheter ablation therapy.

OBJECTIVES We investigated possible differences between male and female patients regarding ablation therapy. BACKGROUND Gender-related differences might have a major impact on different aspects of radiofrequency ablation therapy. Data on this topic are very limited, focusing almost exclusively on success and recurrence rates. METHODS The study population consisted of 894 consecutive patients who underwent catheter ablation of accessory pathways (n = 519) and/or atrioventricular nodal re-entrant tachycardia (AVNRT) (n = 379). There were 418 (46.8%) male and 476 (53.2%) female patients. RESULTS Female patients were referred for ablation later than male patients (185 +/- 143 vs. 157 +/- 144 months after onset of symptoms, p < 0.001) and after having been given more antiarrhythmic drugs (1.6 +/- 1.2 vs. 1.3 +/- 1.1, p < 0.001). Women were more symptomatic, with a higher number of patients having >1 tachycardia episode per month (80.3% vs. 70.3% in men, p < 0.001). Fluoroscopy time, radiofrequency applications, and procedure duration were similar in male and female patients undergoing accessory pathway ablation as well as in male and female patients undergoing AVNRT ablation. No difference was seen in success, complication, and recurrence rates between men and women. CONCLUSIONS Physicians and/or patients tend toward a more conservative approach in female patients. Women are referred for ablation later than are men, after a longer duration of symptoms, and after having been given more antiarrhythmic drugs. However, potential concerns on behalf of physicians or female patients do not seem to be justified: ablation procedures in women had equally high success, low complication, and low recurrence rates as those procedures in male patients.

Atrial fibrillation in chronic non-cardiac disease: Where do we stand?

Atrial fibrillation is the most common arrhythmia, and is associated with increased risk of stroke and death. Most of present knowledge is derived from studies in patients with cardiac disease whilst limited information is available for patients with several chronic non-cardiac conditions like cancer, chronic obstructive pulmonary disease and chronic kidney disease. Although millions of patients are affected and are at risk of adverse prognosis due to co-existent atrial fibrillation, we are left with very limited guidance for management of atrial fibrillation itself and prevention of complications in those patients. In this paper, we review data on incidence, prognostic importance and treatment modalities of atrial fibrillation in patients with cancer, chronic obstructive pulmonary disease, and chronic kidney disease.

Current practice in transvenous lead extraction: a European Heart Rhythm Association EP Network Survey

AIM Current practice with regard to transvenous lead extraction among European implanting centres was analysed by this survey. METHODS AND RESULTS Among all contacted centres, 164, from 30 countries, declared that they perform transvenous lead extraction and answered 58 questions with a compliance rate of 99.9%. Data from the survey show that there seems to be an overall increasing experience of managing various techniques of lead extraction and a widespread involvement of cardiac centres in this treatment. Results and complication rates seem comparable with those of main international registries. CONCLUSION This survey gives an interesting snapshot of lead extraction in Europe today and gives some clues for future research and prospective European registries.

Long-term follow-up after atrial fibrillation ablation in patients with impaired left ventricular systolic function: The importance of rhythm and rate control

BACKGROUND Atrial fibrillation (AF) ablation is increasingly used in patients with reduced left ventricular ejection fraction (LVEF), but long-term outcomes are still unknown. OBJECTIVE To assess the long-term effects of AF ablation in patients with systolic heart failure according to rhythm outcome. METHODS We included 69 patients with LVEF ≤40%, referred for circumferential pulmonary vein isolation with or without additional substrate modification to our institution in 2006-2010. Follow-up included 7-day Holter electrocardiography and echocardiography at baseline and at 6, 12, and 24 months after ablation. A matched control group (n = 69) after AF ablation without heart failure was used for comparison. RESULTS After 28 ± 11 months and 1.6 ± 0.7 ablation procedures, 45 (65%) patients were still in the stable sinus rhythm (SSR) group. LVEF increased from 33 ± 6% to 53 ± 11% (P < .001) in the SSR group and from 33 ± 5% to 38 ± 12% (P = .03) in patients with recurrences (atrial tachycardia/fibrillation group). While LVEF increase was similar in the 2 groups at 6 months (15 ± 12% vs 8 ± 11%; P = .2), further LVEF improvements were observed in the SSR group only. Adjustments for baseline characteristics revealed that the increase in LVEF at 6 months was associated with higher baseline heart rate and not with rhythm outcome. Heart rate did not change in either group after 6 months of follow-up. Complications and procedural data of the study group were similar to the control group. CONCLUSION In patients with heart failure undergoing AF ablation, there is an initial short-term LVEF improvement related to baseline heart rate. However, long-term LVEF improvement is associated with rhythm outcome.

Lipoprotein-Associated Phospholipase A2 Bound on High-Density Lipoprotein Is Associated With Lower Risk for Cardiac Death in Stable Coronary Artery Disease Patients : A 3-Year Follow-Up

OBJECTIVES The aim of this study was to examine the prognostic value of lipoprotein-associated phospholipase A(2) (Lp-PLA(2)) associated with high-density lipoprotein (HDL) (HDL-Lp-PLA(2)) in patients with stable coronary artery disease (CAD). BACKGROUND Lp-PLA(2) is a novel risk factor for cardiovascular disease. It has been postulated that the role of Lp-PLA(2) in atherosclerosis may depend on the type of lipoprotein with which it is associated. METHODS Total plasma Lp-PLA(2) and HDL-Lp-PLA(2) mass and activity, lipids, and C-reactive protein were measured in 524 consecutive patients with stable CAD who were followed for a median of 34 months. The primary endpoint was cardiac death, and the secondary endpoint was hospitalization for acute coronary syndromes, myocardial revascularization, arrhythmic event, or stroke. RESULTS Follow-up data were obtained from 477 patients. One hundred twenty-three patients (25.8%) presented with cardiovascular events (24 cardiac deaths, 47 acute coronary syndromes, 28 revascularizations, 22 arrhythmic events, and 2 strokes). Total plasma Lp-PLA(2) mass and activity were predictors of cardiac death (hazard ratio [HR]: 1.013; 95% confidence interval [CI]: 1.005 to 1.021; p = 0.002; and HR: 1.040; 95% CI: 1.005 to 1.076; p = 0.025, respectively) after adjustment for traditional risk factors for CAD. In contrast, HDL-Lp-PLA(2) mass and activity were associated with lower risk for cardiac death (HR: 0.972; 95% CI: 0.952 to 0.993; p = 0.010; and HR: 0.689; 95% CI: 0.496 to 0.957; p = 0.026, respectively) after adjustment for traditional risk factors for CAD. CONCLUSIONS Total plasma Lp-PLA(2) is a predictor of cardiac death, while HDL-Lp-PLA(2) is associated with lower risk for cardiac death in patients with stable CAD, independently of other traditional cardiovascular risk factors.

Contemporary management of patients undergoing atrial fibrillation ablation: in-hospital and 1-year follow-up findings from the ESC-EHRA atrial fibrillation ablation long-term registry

Aims The ESC-EHRA Atrial Fibrillation Ablation Long-Term registry is a prospective, multinational study that aims at providing an accurate picture of contemporary real-world ablation for atrial fibrillation (AFib) and its outcome. Methods and results A total of 104 centres in 27 European countries participated and were asked to enrol 20–50 consecutive patients scheduled for first and re-do AFib ablation. Pre-procedural, procedural and 1-year follow-up data were captured on a web-based electronic case record form. Overall, 3630 patients were included, of which 3593 underwent an AFib ablation (98.9%). Median age was 59 years and 32.4% patients had lone atrial fibrillation. Pulmonary vein isolation was attempted in 98.8% of patients and achieved in 95–97%. AFib-related symptoms were present in 97%. In-hospital complications occurred in 7.8% and one patient died due to an atrioesophageal fistula. One-year follow-up was performed in 3180 (88.6%) at a median of 12.4 months (11.9–13.4) after ablation: 52.8% by clinical visit, 44.2% by telephone contact and 3.0% by contact with the general practitioner. At 12-months, the success rate with or without antiarrhythmic drugs (AADs) was 73.6%. A significant portion (46%) was still on AADs. Late complications included 14 additional deaths (4 cardiac, 4 vascular, 6 other causes) and 333 (10.7%) other complications. Conclusion AFib ablation in clinical practice is mostly performed in symptomatic, relatively young and otherwise healthy patients. Overall success rate is satisfactory, but complication rate remains considerable and a significant portion of patients remain on AADs. Monitoring after ablation shows wide variations. Antithrombotic treatment after ablation shows insufficient guideline-adherence.