Response and outcomes of cardiac resynchronization therapy in patients with renal dysfunction.

PURPOSE: Renal dysfunction is often associated with chronic heart failure, leading to increased morbi-mortality. However, data regarding these patients after cardiac resynchronization therapy (CRT) is sparse. We sought to evaluate response and long-term mortality in patients with heart failure and renal dysfunction and assess renal improvement after CRT. METHODS: We analyzed 178 consecutive patients who underwent successful CRT device implantation (age 64 ± 11 years; 69% male; 92% in New York Heart Association (NYHA) functional class ≥ III; 34% with ischemic cardiomyopathy). Echocardiographic response was defined as ≥ 15% reduction in left ventricular end-systolic diameter and clinical response as a sustained improvement of at least one NYHA functional class. Renal dysfunction was defined as an estimated glomerular filtration rate (eGFR) below 60 mL/min/1.73 m2. RESULTS: Renal dysfunction was present in 34.7%. Renal dysfunction was not an independent predictor of echocardiographic response (OR 1.109, 95% CI 0.713-1.725, p 0.646) nor clinical response (OR 1.003; 95% CI 0.997-1.010; p 0.324). During follow-up (mean 55.2 ± 32 months), patients with eGFR < 60mL/min/1.73 m2 had higher overall mortality (HR 4.902, 95% CI 1.118-21.482, p 0.035). However, clinical response in patients with renal dysfunction was independently associated with better long-term survival (HR 0.236, 95% CI 0.073-0.767, p 0.016). Renal function was significantly improved in patients who respond to CRT (ΔeGFR + 5.5 mL/min/1.73 m2 at baseline vs. follow-up, p 0.049), while this was not evident in nonresponders. Improvements in eGFR of at least 10 mL/min/1.73 m2 were associated with improved survival in renal dysfunction patients (log-rank p 0.036). CONCLUSION: Renal dysfunction was associated with higher long-term mortality in CRT patients, though, it did not influence echocardiographic nor functional response. Despite worse overall prognosis, renal dysfunction patients who are responders showed long-term survival benefit and improvement in renal function following CRT.

What happens to non-responders in cardiac resynchronization therapy?

INTRODUCTION AND OBJECTIVES: Left ventricular reverse remodeling (LVRR) is strongly related to the long-term prognosis of patients undergoing cardiac resynchronization therapy (CRT). The aim of this study was to assess the long-term clinical outcome of patients without LVRR at six months after CRT implantation and to determine the prognostic impact of clinical response in this population. METHODS: We analyzed 178 consecutive patients who underwent successful CRT device implantation (age 64±11 years; 69% male; 89% in New York Heart Association [NYHA] functional class III; 35% with ischemic cardiomyopathy). Clinical status and echocardiographic parameters were determined before and six months after CRT implantation. We identified those without criteria for LVRR (≥10% increase in left ventricular ejection fraction with ≥15% reduction in left ventricular end-systolic diameter compared to baseline). Clinical responders were defined by a sustained improvement of at least one NYHA functional class. RESULTS: At six-month assessment after CRT, 109 (61%) patients showed LVRR. During a mean follow-up of 56±21 months, 47 (26%) patients died, with higher mortality in the group without LVRR (36% vs. 20%, p=0.023). Clinical response was greater in patients with LVRR (88% vs. 55%, p<0.001). In patients without LVRR, clinical response to CRT was the strongest independent predictor of survival (hazard ratio: 0.120; 95% confidence interval: 0.039-0.366; p<0.001). CONCLUSION: Although patients without LVRR six months after CRT implantation had a worse prognosis, with higher all-cause mortality, clinical response can be an independent predictor of survival in this population.

Benefits of cardiac resynchronization therapy in "very dilated cardiomyopathy".

INTRODUCTION: Recent clinical trials have studied parameters that could predict response to cardiac resynchronization therapy (CRT) in patients with advanced heart failure. Left ventricular end-diastolic dimension (LVEDD) is regarded as a possible predictor of response to CRT. OBJECTIVE: To study the response to CRT in patients with very dilated cardiomyopathy, i.e. those at a more advanced stage of the pathology, analyzing both the responder rate and reverse remodeling in two groups of patients classified according to LVEDD. METHODS: We performed a retrospective analysis of 71 patients who underwent CRT (aged 62 +/- 11 years; 65% male; 93% in NYHA functional class > or = III; 31% with ischemic cardiomyopathy; left ventricular ejection fraction [LVEF] 25.6 +/- 6.8%; 32% in atrial fibrillation; QRS 176 +/- 31 ms). Twenty-two (31%) patients with LVEDD > or = 45 mm/m2 (49.2 +/- 3.5 mm/m2) were considered to have very dilated cardiomyopathy (Group A) and 49 patients had LVEDD > 37 mm/m2 and < 45 mm/m2 (39.4 +/- 3.8 mm/m2) (Group B). All patients were assessed by two-dimensional echocardiography at baseline and six months after CRT. The following parameters were analyzed: NYHA functional class, LVEF and LVEDD. Responders were defined clinically (improvement of > or = 1 NYHA class) and by echocardiography, with a minimum 15% increase over baseline LVEF combined with a reduction in LVEDD (reverse remodeling). RESULTS: There were no significant differences in baseline demographic characteristics between the two groups. At six-month followup, we observed an improvement in LVEF (delta 8.5 +/- 11.8%) and a reduction in LVEDD (delta 3.7 +/- 6.8 mm/m2), with fifty-seven (79%) patients being classified as clinical responders. The percentage of patients with reverse remodeling was similar in both groups (64% vs. 73%, p = NS), as were percentages of improved LVEF (delta 6.3 +/- 11% vs. delta 9.6 +/- 12%; p = NS) and decreased LVEDD (delta 3.7 +/- 5.5 mm/m2 vs. delta 3.7 +/- 7.4 mm/m2; p = NS). We found a higher percentage of clinical responders in patients with very dilated cardiomyopathy (96% vs. 72%, p < 0.05). CONCLUSION: In this study, a significant number of responders showed reverse remodeling after CRT. Although a higher percentage of patients with very dilated cardiomyopathy showed improvement in functional class, the extent of reverse remodeling was similar in both groups.

Echocardiographic variables predictive of appropriate therapies for ventricular tachyarrhythmia in patients undergoing combined cardiac resynchronization therapy.

INTRODUCTION: The significant risk of sudden arrhythmic death in patients with congestive heart failure and electromechanical ventricular dyssynchrony has led to increased use of combined cardiac resynchronization therapy defibrillator (CRT-D) devices. OBJECTIVES: To evaluate the echocardiographic variables in patients undergoing CRT-D that predict the occurrence of appropriate therapies (AT) for ventricular tachyarrhythmia. METHODS: We analyzed 38 consecutive patients (mean age 60 +/- 12 years, 63% male) with echocardiographic evaluation before and 6 months after CRT-D implantation. Patients with AT were identified in a mean follow-up of 471 +/- 323 days. A standard echocardiographic study was performed including tissue Doppler imaging (TDI). Responders were defined as patients with improvement in NYHA class of < or = 1 in the first six months, and reverse remodeling as a decrease in left ventricular end-systolic volume of < or = 15% and/or an increase in left ventricular ejection fraction of > 25%. RESULTS: The responder rate was 74%, and the reverse remodeling rate was 55%. AT occurred in 21% of patients, who presented with greater left ventricular end-diastolic internal diameter (LVEDD) before implantation (86 +/- 8 vs. 76 +/- 11 mm, p = 0.03) and at 6 months (81 +/- 8 vs. 72 +/- 14 mm, p = 0.08), and increased left ventricular end-systolic internal diameter (66 +/- 14 vs. 56 +/- 14 mm, p = 0.03) and lower ejection fraction (24 +/- 6 vs. 34 +/- 14%, p = 0.08) at 6 months. In the group with AT, the responder rate was lower (38 vs. 83%, p = 0.03), without significant differences in reverse remodeling (38% for the AT group vs. 60%, p = 0.426) or in the other variables. By univariate analysis, predictors of AT were LVEDD before implantation and E' after implantation. Age, gender, ischemic etiology, use of antiarrhythmic drugs, reverse remodeling and the other echocardiographic parameters did not predict AT. In multivariate logistic regression analysis, both LVEDD before implantation (OR 1.24, 95% CI 1.04-1.48, p = 0.019) and postimplantation E' (OR 0.27, 95% CI 0.09-0.76, p = 0.014) remained as independent predictors of AT. CONCLUSIONS: In patients undergoing CRT-D, episodes of ventricular tachyarrhythmia occur with high incidence, independently of echocardiographic response, with LVEDD before implantation and E' after implantation as the only independent predictors of AT in the medium-term. These results highlight the importance of combined devices with defibrillation capability.

National Registry on Cardiac Electrophysiology 2007 and 2008.

Clinical electrophysiology remains one of the most dynamic areas of cardiology, with continuing developments in equipping centers with more modern mapping and navigation systems. This has enabled an increase in the number and variety of interventions, resulting in significant improvements in results of therapeutic ablation of arrhythmias and prevention of sudden cardiac death. In this phase of transition towards implementation of a computerized national registry with nationwide data transmitted via the internet, publication of the registry in its previous form, although requiring more work, still seems justified, in order to appraise and disseminate qualitative and quantitative developments in this activity and enable comparisons with what is being done internationally, assess the centers' training capacity and inform national and European health authorities of the activities and real needs in this sector. The authors analyze the number and type of procedures performed during 2007 and 2008 based on a survey sent to centers performing diagnostic and interventional electrophysiology (16 centers in 2007 and 2008) and/or implanting cardioverter-defibrillators (ICDs) (19 centers in 2007 and 21 in 2008). Compared to 2006, one more center began interventional electrophysiology in 2007 and two centers began implanting ICDs in 2008. In the years under review, 2060 electrophysiological studies were performed in 2007 and 2007 were performed in 2008, of which 74 and 79.5% respectively were followed by therapeutic ablation, making totals of 1523 and 1596 ablations (increases of 10.7 and 4.6% from previous years). Atrioventricular nodal reentrant tachycardia was the main indication for ablation (28.4 and 28.7%), followed by accessory pathways (26.8 and 25.4%), atrial flutter (20.8 and 19.7%), atrial fibrillation (13.9 and 14.6%), ventricular tachycardia (4.7 and 5.1%), atrial tachycardia (2.8 and 2.6%) and atrioventricular junction ablation (2.7 and 3.9%). Regarding ICDs, a total of 890 devices were implanted in 2007 and 1040 devices in 2008, of which 63 and 75 respectively were battery replacements and 827 and 965 were first implantations, with the following distribution: single chamber--53.7% in 2007 and 61.4% in 2008; dual chamber--13.8 and 8.4% respectively in 2007 and 2008; resynchronization systems with ICD--32.5% in 2007 and 30.2% in 2008. The figures for first implantations show growth of 18.5% between 2006 and 2007 and 14.3% between 2007 and 2008. First implantations increased from 67.4 devices per million population in 2006 to 82.7 in 2007 and 96.5 in 2008.

National Registry on Cardiac Electrophysiology--2006.

Clinical electrophysiology is one of the areas of cardiology that has seen most growth in Portugal, particularly in interventional cardiology, which includes ablation of arrhythmias and prevention of sudden cardiac death. The annual publication of a national registry enables us to assess qualitative and quantitative progress, compare our results with international data, assess the centers' training capabilities and inform health authorities of the activities and needs of the sector. The authors analyze the number and type of procedures performed during 2006 based on a survey sent to 19 national centers (15 public and 4 private) that performed diagnostic and interventional electrophysiology (15 centers) and/or implanted cardioverter-defibrillators (ICDs) (19 centers) in that year. The number of electrophysiology centers remained unchanged from 2005, but four new centers began implanting ICDs in 2006. In the year under review, 1805 electrophysiological studies were performed, 75.3% of which were followed by ablation therapy, a total of 1360 ablation procedures (a 22.3% increase over the previous year). Accessory pathways were the main indication for ablation (32%), followed by atrial flutter (25%), atrioventricular nodal reentrant tachycardia (23%), atrial fibrillation (10%), ventricular tachycardia (5%), atrial tachycardia (3%) and atrioventricular junction ablation (2%). In 2006, a total of 738 ICD devices were implanted, of which 64 were battery replacements and 674 were first implantations, with the following distribution: 346 single chamber (51.3%), 98 dual chamber (14.5%) and 230 integrated in ventricular resynchronization systems (34.1%). These figures reflect a lower growth rate than that of 2005, even though in 2006 first implantations rose from 54.7 to 67.4 devices per million population. The ICD implantation rate in Portugal is still far below the European average, which means there is a continuing need to raise awareness of this therapeutic option among the Portuguese medical community. With regard to the training capabilities currently available in Portugal, only 5 centers (all public) had a sufficient level of activity to fulfill the requirements stipulated for the subspecialty of cardiac electrophysiology. As for implantation of ICDs, 12 centers implanted more than 10 units, the minimum annual curricular limit for this subspecialty.

Head-up tilt testing with different nitroglycerin dosages: experience in elderly patients with unexplained syncope.

AIMS: Protocols using sublingual nitrates have been increasingly used to improve diagnostic accuracy of head-up tilt testing (HUT). Nevertheless, exaggerated responses to nitrates have been frequently described, particularly in elderly patients. The aim of this article is to evaluate, in an elderly population with unexplained syncope, whether the impact of sublingual nitroglycerin (NTG) used as a provocative agent is dose-dependent. METHODS AND RESULTS: One hundred and twenty consecutive elderly patients submitted to HUT using NTG after an asymptomatic drug-free phase were studied. Patients were divided into three groups according to the NTG dosage: 500, 375 and 250 microg. The test was considered positive when there was reproduction of symptoms with bradycardia and/or arterial hypotension. A gradual decrease in the blood pressure after NTG was considered an exaggerated response to nitrates. There were no differences in the clinical characteristics of the different subgroups. A positive test was obtained in 50% of the patients in each group. The rate of exaggerated responses was identical in all groups and ranged between 15 and 17%. CONCLUSION: In an elderly population with syncope of unknown origin submitted to HUT, the response to NTG is not dose-dependent, and no difference was found in the rate of exaggerated responses to nitrates with different NTG dosages.

Rupture of a congenital aneurysm of the non-coronary sinus of Valsalva into the right atrium.

We present the case of a patient evaluated for a continuous murmur, in which a ruptured congenital sinus of Valsalva aneurysm with fistulization to the right atrium was demonstrated by echocardiography. The authors review the relevant clinical features of this entity.

Permanent junctional reciprocating tachycardia: an incessant tachycardia in children.

UNLABELLED: Permanent junctional reciprocating tachycardia is an infrequent form of reentrant supraventricular tachycardia but is the commonest incessant tachycardia in childhood. The persistent nature of the tachycardia can lead to heart failure secondary to left ventricular dysfunction and the arrhythmia is often refractory to drug control. STUDY OBJECTIVE: To review the main clinical features and therapeutic options currently available for this arrhythmia. DESIGN: Retrospective study. PATIENTS: A group of 5 children with a diagnosis of permanent junctional reciprocating tachycardia. RESULTS: Age at presentation ranged between 14 days and 12 years. Three were asymptomatic. The first echocardiogram displayed left ventricular dilation and decreased shortening fraction in one child. Pharmacological therapy was initially successful in all. During follow-up (0.2-4.5 years) the arrhythmia became resistant to medication in one case and radiofrequency ablation was carried out. CONCLUSIONS: Permanent junctional reciprocating tachycardia has a wide range of clinical presentations. Pharmacological therapy is recommended, but radiofrequency ablation is the definitive treatment and only depends on patient age.