Trends in ablation procedures in Greece over the 2008-2018 period: Results from the Hellenic Cardiology Society Ablation Registry.

OBJECTIVE: In 2008, the radiofrequency ablation (RFA) procedures registry of the Hellenic Society of Cardiology was created. This online database allowed electrophysiologists around the country to input data for all performed ablation procedures. The aim of this study is to provide a thorough report and interpretation of the data submitted to the registry between 2008 and 2018. METHODS: In 2008, a total of 27 centers/medical teams in 24 hospitals were licensed to perform RFA in Greece. By 2018, the number had risen to 31. Each center was tasked with inserting their own data into the registry, which included patient demographics (anonymized), type of procedure and technique, complications, and outcomes. RESULTS: A total of 18587 procedures in 17900 patients were recorded in the period of 2008-2018. By 2018, slightly more than 70% of procedures were performed in 7 high-volume centers (>100 cases/year). The most common procedure since 2014 was atrial fibrillation ablation, followed by atrioventricular nodal reentry tachycardia ablation. Complication rates were low, and success rates remained high, whereas the 6-month relapse rates declined steadily. CONCLUSION: This online RFA registry has proved that ablation procedures in Greece have reached a very high standard, with results and complication rates comparable to European and American standards. Ablation procedures for atrial fibrillation are increasing constantly, with it being the most common intervention over the last 6-year period, although the absolute number of procedures still remains low, compared to other European countries.

"Real life" longevity of implantable cardioverter-defibrillator devices.

BACKGROUND: Manufacturers of implantable cardioverter-defibrillators (ICDs) promise a 5- to 9-year projected longevity; however, real-life data indicate otherwise. The aim of the present study was to assess ICD longevity among 685 consecutive patients over the last 20 years. HYPOTHESIS: Real-life longevity of ICDs may differ from that stated by the manufacturers. METHODS: The study included 601 men and 84 women (mean age, 63.1 ± 13.3 years). The underlying disease was coronary (n = 396) or valvular (n = 15) disease, cardiomyopathy (n = 220), or electrical disease (n = 54). The mean ejection fraction was 35%. Devices were implanted for secondary (n = 562) or primary (n = 123) prevention. Single- (n = 292) or dual-chamber (n = 269) or cardiac resynchronization therapy (CRT) devices (n = 124) were implanted in the abdomen (n = 17) or chest (n = 668). RESULTS: Over 20 years, ICD pulse generator replacements were performed in 238 patients (209 men; age 63.7 ± 13.9 years; ejection fraction, 37.7% ± 14.0%) who had an ICD for secondary (n = 210) or primary (n = 28) prevention. The mean ICD longevity was 58.3 ± 18.7 months. In 20 (8.4%) patients, devices exhibited premature battery depletion within 36 months. Most (94%) patients had none, minor, or modest use of ICD therapy. Longevity was longest for single-chamber devices and shortest for CRT devices. Latest-generation devices replaced over the second decade lasted longer compared with devices replaced during the first decade. When analyzed by manufacturer, Medtronic devices appeared to have longer longevity by 13 to 18 months. CONCLUSIONS: ICDs continue to have limited longevity of 4.9 ± 1.6 years, and 8% demonstrate premature battery depletion by 3 years. CRT devices have the shortest longevity (mean, 3.8 years) by 13 to 17 months, compared with other ICD devices. These findings have important implications, particularly in view of the high expense involved with this type of electrical therapy.

Peak Early Diastolic Transmitral Velocity As A Surrogate Marker Of Short-Term Atrial Fibrillation Recurrence After Electrical Cardioversion.

OBJECTIVES: The aim of this study was to assess if peak early diastolic transmitral velocity (E-wave) can be used as a surrogate marker of short-term atrial fibrillation (AF) recurrence. METHODS: We prospectively studied 57 consecutive patients who underwent electrical cardioversion (ECV) for AF and successfully converted to sinus rhythm. N-terminal brain natriuretic peptide levels (BNP) before and after ECV was measured in all patients. The follow-up included physical examination and a 12-lead electrocardiogram 14 days and one month after the ECV. RESULTS: In 42.1% patients AF recurred during one-month follow-up period. Gender, presence of mitral regurgitation, treatment with angiotensin II receptor blocker and left atrium diameter independently influenced E-wave velocity before ECV. E-wave velocity fell immediately after successful ECV (94.0±27 cm/s vs 79.7±23 cm/s, P<0.0001). E-wave velocity before ECV>94 cm/s and E-wave velocity after ECV >80 cm/s were predictors of one-month AF recurrence [(Hazard Ratio) HR=3.62 with 95% CI=1.49-8.78 and HR=3.76 with 95% CI=1.40-10.10, respectively]. E-wave velocity before and E-wave velocity after ECV remained predictors of AF recurrence but only in non-hypertensive patients (HR=1.01 with 95% C.I=1.01-1.03 and HR=1.03 with 95% C.I=1.01-1.06, respectively). Similarly, BNP levels before and after ECV were associated with an increased the risk of AF recurrence (HR=1.14 with 95% C.I 1.01-1.28 and HR= 1.16 with 95% C.I 1.03- 1.31, respectively). The addition of BNP levels to E-wave velocity before ECV appeared to have incremental value on short-term AF recurrence but at a marginally statistical significance (LR chi2=3.28, p=0.07). CONCLUSIONS: E-wave velocity before and after ECV appears to be a marker of short-term recurrence of AF.

Relationship between pre-implant ejection fraction and outcome after cardiac resynchronization therapy in symptomatic patients.

BACKGROUND: Left-ventricular ejection fraction (LVEF) is regarded as a strong predictor for morbidity and mortality in heart failure patients. The aim of the analysis was to assess the relationship between pre-implant LVEF and outcome of patients with advanced heart failure who received cardiac resynchronization therapy (CRT). METHODS: We analysed the two-year follow-up of 366 patients who had been enrolled in the MASCOT study which included NYHA class III/IV patients with a class I CRT indication. Pre-implant LVEF was stratified by tertile. RESULTS: The boundaries for pre-implant LVEF were < 22% (n = 128; 18.2 +/- 3.1%; T(low)), 22% to 28% (n = 121; 25.4 +/- 1.4%; T(middle)) and > 28% (n = 117; 32.6 +/- 3.9%; T(high)) for each tertile.Two-year post-implant LVEF was 32.0 +/- 11.5% (T(low)), 33.7 +/- 10.8% (T(middle)) and 36.4 +/- 9.9% (T(high)). T(Iow) had a greater increase between pre- and post-implant LVEF compared to T(middle) (P = 0.03) and T(high) (P = 0.0001). NYHA class improved similarly among the three groups as well as the quality of life score. No significant differences were detected between the three groups for all-cause mortality, cardiac death, all-cause hospitalization, and hospitalization due to worsening heart failure. CONCLUSIONS: Symptomatic heart failure patients with a wide QRS complex and a severe impaired LV function had a better improvement of their pre-implant LVEF than patients with a more preserved LVEF. This may be one reason that in these patient groups long-term morbidity and mortality were not related to their pre-implant LVEF. Pre-implant LVEF was in symptomatic CRT patients not predictive for their long-term cardiovascular morbidity and mortality.

Gender-related safety and efficacy of cardiac resynchronization therapy.

BACKGROUND: Cardiac resynchronization therapy (CRT) is an established therapy for patients with chronic heart failure (CHF) and a broad QRS complex. Gender-related safety and efficacy data are necessary for informed patient decision-making for female patients with CHF. The aim of the study was to assess the effects of gender on the outcome of CRT in highly symptomatic heart failure patients. HYPOTHESIS: Gender may have an effect on the outcome of heart failure patients undergoing cardiac resynchronisation therapy. METHODS: The study analyzed the 2-year follow-up of 393 New York Heart Association (NYHA) class III/IV patients with a class I CRT indication enrolled in the Management of Atrial Fibrillation Suppression in AF-HF Comorbidity Therapy (MASCOT) study. RESULTS: In female patients (n = 82), compared with male patients (n = 311), CHF was more often due to dilated cardiomyopathy (74% vs 44%, respectively; P < 0.0001). Females also had a more impaired quality-of-life score and a smaller left ventricular end-diastolic diameter (LVEDD). Women were less likely than men to have received a CRT defibrillator (35% vs 61%, respectively; P < 0.0001). After 2 years, the devices had delivered more biventricular pacing in women than in men (96% ± 13% vs 94% ± 13%, respectively; P < 0.0004). Women had a greater reduction in LVEDD than did men (-8.2 mm ± 11.1 mm vs -1.1 mm ± 22.1 mm, respectively; P < 0.02). Both genders improved similarly in NYHA functional class. Women reported greater improvement than men in quality-of-life score (-21.1 ± 26.5 vs -16.2 ± 22.1, respectively; P < 0.0001). After adjustment for cardiovascular history, women had lower all-cause mortality (P = 0.0007), less cardiac death (P = 0.04), and fewer hospitalizations for worsening heart failure (P = 0.01). CONCLUSIONS: Females exhibited a better response to CRT than did males. Because females have such impressive benefits from CRT, improved screening and advocacy for CRT implantation in women should be considered.

One-year outcome after CRT implantation in NYHA class IV in comparison to NYHA class III patients.

BACKGROUND: The aim of the analysis was to compare the outcome of heart failure patients in New York Heart Association (NYHA) class IV to that of NYHA class III patients 1 year after implantation of a CRT device. METHODS: The analysis was based on the 405 CRT patients enrolled in the MASCOT trial. At enrollment, 350 patients (86%) were in NYHA class III and 55 (14 %) were in NYHA class IV. RESULTS: At 1-year follow-up, the improvement of the ejection fraction was not statistically significantly different between NYHA class III (+7.6 ± 11.7%) and NYHA class IV patients (+9.2 ± 14.2 %; p = 0.78). NYHA class IV patients had a better mean NYHA class reduction with -1.93 ± 0.83 than NYHA class III patients with -0.93 ± 0.70 (p < 0.0001). There was a greater mean quality of life improvement in NYHA class IV (-27.2 ± 20.9) compared to NYHA class III (-17.7 ± 23.9; p = 0.02). All-cause mortality as well as cardiac mortality remained higher in NYHA class IV with 25.5 and 16.4% than in NYHA class III with 7.1 and 3.1% (p < 0.0001). CONCLUSIONS: In this study, 14% of all patients receiving a CRT device had NYHA class IV at implantation. The data support the concept to implant a CRT device in NYHA class IV patients, because at 1 year after implantation, they experienced better symptomatic improvement compared to NYHA class III patients. The higher cardiac as well as non-cardiac mortality resulted in a fivefold higher all-cause mortality compared to NYHA class III patients.

Lead complications, device infections, and clinical outcomes in the first year after implantation of cardiac resynchronization therapy-defibrillator and cardiac resynchronization therapy-pacemaker.

AIMS: The decision to implant a cardiac resynchronization therapy (CRT) system with (defibrillator, CRT-D) or without (pacemaker, CRT-P) cardioverter defibrillator should weigh its benefits and risks. This study examined the (i) incidence of loss of capture and infectious complications and (ii) 1-year clinical outcomes of 402 CRT-D and CRT-P recipients enrolled in the MASCOT study. METHODS AND RESULTS: The indications for CRT-D or CRT-P were posed by the implanting physicians. All (i) losses of atrial and right and left ventricular capture, (ii) system-related infections, and (iii) clinical outcomes, including hospitalizations for worsening heart failure (HF) and deaths from all causes, were recorded up to 1 year of follow-up. Cardiac resynchronization therapy-defibrillator was implanted in 228 (57%) and CRT-P in 174 (43%) patients. The incidence of loss of capture was greater in CRT-D with 21 patients (9.2%) than in CRT-P with 6 patient (3.5%) recipients (P = 0.01), while the infection rates were 1.3% (3 patients) and 1.2% (2 patients), respectively (ns). In the CRT-D group, 42 of 228 patients (18.4%) died or were hospitalized for HF, compared with 38 of 174 patients (21.8%) in the CRT-P group (ns). In the CRT-D group, 23 patients (10.1%) were hospitalized for worsening HF and 20 (8.8%) patients died, vs. 22 (12.6%) and 19 (10.9%) patients, respectively, in the CRT-P group (ns for both comparisons). CONCLUSIONS: Cardiac resynchronization therapy-defibrillator was implanted in 57% of candidates for CRT. Within 1 year after device implant, the incidence of loss of capture at any lead was nearly three-fold greater among CRT-D than among CRT-P recipients. System-related infections were infrequent and clinical outcomes were similar in both groups.

Radiofrequency ablation procedures in Greece: initial experience and results from the national registry 2008-2010.

INTRODUCTION: In 2008 the radiofrequency ablation procedures (RFA) registry of the Hellenic Cardiological Society (HCS) was created. This is a dynamic, web-based application, which acts as the interface for storing and retrieving patients' demographic data and ablation procedures. Access to the site is permitted only to registered users. The purpose of this study is to report the results of RFA procedures performed in Greece over the 2008-2010 period. METHODS: There are 27 centers in 24 hospitals that are licensed to perform RFA in Greece. During the period 2008-2010, 3541 RFA procedures were performed in 3344 patients in 23 centers. Four centers did not contribute data at all for various reasons. It is interesting that nearly 50% of the total number of procedures were performed at 3 high volume centers (>100 cases/year). RESULTS: The most common procedure was slow pathway ablation for atrioventricular reentrant tachycardia, the second was ablation of accessory pathway related tachycardias, and the third was ablation of atrial fibrillation. Success rates were high (92.1%), the complication rate was 3% (serious complications <1%) and total relapse rate was 8.7% at six months' follow up. CONCLUSIONS: The electronic RFA registry in Greece confirmed that all RFA procedures are performed in Greece with high success and low complication rates, comparable to the European and US standards. The experience and results from the first three-year period using the registry are very interesting and encouraging, thus indicating the need for development of similar databases at the national level.

Disorders of the autonomic nervous system in patients with Brugada syndrome: a pilot study.

INTRODUCTION: The aim of this study was to examine autonomic disorders in patients with Brugada syndrome by performing a cardiac sympathetic innervation evaluation, a head-up tilt-test (HUT) and heart rate variability (HRV) analysis. METHODS AND RESULTS: We enrolled 20 patients with Brugada syndrome (mean age 42.5 +/- 8.8 years), 9 with spontaneous and 11 with an induced type 1 electrocardiogram (ECG) in the setting of symptoms and 20 age-matched controls. All subjects underwent a HUT with parallel measurements of plasma catecholamines and cortisol, a (123)I-metaiodobenzylguanidine single photon emission tomography, and HRV evaluation. Ten control subjects participated in the innervation portion of the study. The tilt-test with clomipramine challenge was positive in 15 of 20 (75%) patients (7 spontaneous, 8 induced) and in 1 in controls (P < 0.01). A sympathoadrenal imbalance was shown in positive tests. The pattern of innervation in all groups was heterogenic and similar to controls with a trend towards lower measurements in patients with a spontaneous type 1 ECG and a positive HUT. HRV analysis did not reveal any significant differences during day and night. Four patients (20%) had sustained ventricular arrhythmias during a follow-up of 31.1 +/- 8.6 months, but no correlations with innervation or response to tilting were found. CONCLUSION: A high susceptibility to vasovagal syncope was observed in patients with Brugada syndrome, which could be disease-related symptoms. Conversely, sympathetic innervation was observed to follow a physiological, heterogenic pattern; however, these factors did not have prognostic value for life-threatening arrhythmias.

Ablation of atrial tachycardias with radiofrequency current after surgical repair of complex congenital heart defects.

INTRODUCTION: Atrial tachycardias are a common problem following the surgical repair of complex congenital heart defects (CHD) and have a poor response to medication. The aim of this study was to describe the results of the treatment of such tachycardias with radiofrequency ablation in our hospital. METHODS: A retrospective study was performed of the medical records and electronically stored data from electrophysiological studies (EPS) and ablation procedures in patients with atrial tachycardias following the surgical repair of CHD. Established electrophysiological techniques were used in all patients, while newer three-dimensional imaging methods were also employed in some cases. Ablation was carried out using a radiofrequency generator and catheters with a 4-10 mm terminal electrode. RESULTS: Twenty-two patients aged 11-45 years (30.6 +/- 10.8), including 9 women, underwent an EPS and ablation of atrial tachycardias after the surgical repair of CHD. All had recurrent tachycardias refractory to antiarrhythmic medication. The anatomical diagnoses were tetralogy of Fallot (8), transposition of the great arteries (6), single ventricle (3), and other (5). Most patients had typical atrial flutter and/or incisional atrial reentrant tachycardia. The initial success rate of ablation for all arrhythmias was 88% in patients with tetralogy of Fallot, 83% for transposition of the great arteries, 66% for single ventricle, and 80% for the other diagnoses. Three-dimensional imaging was of significant assistance in mapping and ablation and in reducing the duration of fluoroscopy. Two vascular complications (femoral arteriovenous fistulae) were observed. The tachycardia recurrence rate was 54%. After repeated procedures, 59% of patients were free of arrhythmias and antiarrhythmic medications. No patient with a single ventricle remained free of arrhythmias during follow up, while in the other groups the arrhythmia/drug-free rate was 66-75%. Two patients with unsuccessful ablation died, one from heart failure and the other because of the tachycardia. CONCLUSIONS: Atrial tachycardias in patients with surgically treated CHD are associated with increased morbidity and mortality. Radiofrequency ablation has satisfactory results. In spite of the high relapse rate, a significant number of patients can become free of arrhythmias after repeat procedures.

Cardiac resynchronization therapy decreases the mitral coaptation point displacement in heart failure patients.

BACKGROUND: In patients with left ventricular (LV) dysfunction the mitral leaflet coaptation point (CPMA) is displaced towards the LV apex. The aim of our study was to estimate the value of CPMA measurement as a simple index regarding the acute effects of cardiac resynchronization therapy (CRT), which is coming to be an established method of treatment for congestive heart failure (CHF). METHODS: We studied 20 patients with CHF (NYHA III-IV) and LV ejection fraction (LVEF) 22 +/- 4%. All patients received CRT and an echocardiogram was performed within 24-48 hours. The echocardiographic indices LV end-diastolic diameter (LVEDD) and end-systolic diameter (LVESD), LVEF, mitral annulus diameter (MAD), and the degree of intraventricular desynchronization, were measured at CRT off and CRT on. The CPMA, the distance between the coaptation point of the mitral leaflets and the mitral annulus, was measured from the apical 4-chamber view in end-systole at both CRT on and CRT off. RESULTS: CRT improved both the contractility and dimensional indices in CHF patients. CPMA decreased from 11.3 +/- 2 mm at CRT off to 9.1 +/- 1.8 mm after CRT on (p < 0.001) and MAD from 38.9 +/- 3.9 mm at CRT off to 37.5 +/- 3.7 mm at CRT on (p < 0.002). LVEF improved from 24.5 +/- 5.7% at CRT off to 29.5 +/- 5.1% at CRT on (p < 0.001). There was an improvement in LV synchronization from 88 +/- 7 ms at CRT off to 48 +/- 3 ms at CRT on (p < .001). CPMA was correlated with MAD (r = 0.52, p < 0.05 and r = 0.59, p < 0.05 at CRT off and CRT on, respectively). Moreover, the absolute change in CPMA was correlated with LVESD (r = 0.68) and LVEDD (r = 0.65), both p < 0.05, with the time difference of the basal segments of the septal and lateral wall at CRT on (r = 0.68, p < 0.01), and inversely correlated with LVEF (r = -0.55, p < 0.05). CONCLUSION: In patients with severe LV systolic dysfunction and dilatation CRT was associated with an improvement in both CPMA and MAD.

Cardiac and sternocleidomastoid muscle involvement in Duchenne muscular dystrophy: an MRI study.

OBJECTIVE: To examine the extent of cardiac muscle and sternocleidomastoid muscle (SCM) involvement detected by MRI measurement of T2 relaxation time in patients with Duchenne muscular dystrophy (DMD) and no cardiorespiratory symptoms. DESIGN: Prospective controlled study. SETTING: Teaching referral hospital and university hospital. SUBJECTS: Seventeen patients with DMD (age range, 7 to 25 years) and 17 age-matched control subjects. All patients were free of cardiac or respiratory complaints and had normal ECG, echocardiograph, and Holter monitor examination findings. METHODS: We assessed respiratory function by means of standard pulmonary function testing. MRI measurements included the T2 relaxation time of the myocardium and the SCM in patients and control subjects. RESULTS: The FVC and FEV1 values were lower in patients with DMD than in age-matched control subjects, whereas the FEV1/FVC ratio was normal in all subjects. Patients with DMD had lower T2 relaxation time of the heart (37.8 +/- 6.1 ms vs 58.1 +/- 7.1 ms, p < 0.001) and lower T2 relaxation time of the right SCM (24.5 +/- 2.6 ms vs 42.2 +/- 1.3 ms, p < 0.001) and left SCM (23.2 +/- 3.2 ms vs 42.2 +/- 1.6 ms, p < 0.001), compared to control subjects (+/- SD). In children (< 12 years of age), the T2 of the SCM was lower than that of the control subjects, but T2 of the heart did not differ between the two groups. In the patient group, T2 relaxation time of the heart decreased with age (r = - 0.80, p < 0.001). In patients with FVC < 80% of predicted, the T2 values of the heart were lower than the T2 values of patients with FVC > or = 80% of predicted (35.6 +/- 5.8 ms vs 41.8 +/- 4.6 ms, p < 0.05). CONCLUSIONS: MRI measurements of the T2 relaxation time in the myocardium and SCM of patients with DMD and no cardiorespiratory symptoms are abnormal, indicating altered tissue composition. These measurements may prove a clinically useful test for monitoring cardiac and respiratory muscle involvement in these patients.