Maurits S. Buiten

The dialysis procedure as a trigger for atrial fibrillation: new insights in the development of atrial fibrillation in dialysis patients

Aims Atrial fibrillation (AF) is common in dialysis patients and is associated with increased morbidity and mortality. The pathophysiology may be related to common risk factors for both AF and renal disease or to dialysis-specific factors. The purpose of this study was to determine whether and how AF onset relates to the dialysis procedure itself. Methods All dialysis patients enrolled in the implantable cardioverter defibrillator-2 (ICD-2) trial until January 2012, who were implanted with an ICD, were included in this study. Using the ICD remote monitoring function, the exact time of onset of all AF episodes was registered. Subsequently, this was linked to the timing of dialysis procedures. Results For the current study, a total of 40 patients were included, follow-up was 28±16 months, 80% male, 70±8 years old. A total of 428 episodes of AF were monitored in 14 patients. AF onset was more frequent on the days of haemodialysis (HD) (p<0.001) and specifically increased during the dialysis procedure itself (p=0.04). Patients with AF had a larger left atrium (p<0.001) and a higher systolic blood pressure before and after HD (p<0.001). Conclusion This study provides insight in the exact timing of AF onset in relation to the dialysis procedure itself. In HD patients, AF occurred significantly more often on a dialysis day and especially during HD. These findings might help to elucidate some aspects of the pathophysiology of AF in dialysis patients and could facilitate early detection of AF in these high-risk patients.

The clinical course of patients with implantable cardioverter-defibrillators: Extended experience on clinical outcome, device replacements, and device-related complications

BACKGROUND Large randomized trials demonstrated the beneficial effect of implantable cardioverter-defibrillator (ICD) and cardiac resynchronization therapy-defibrillator (CRT-D) treatments in selected patients. Data on long-term follow-up of patients outside the setting of clinical trials are scarce. OBJECTIVE The aim of this study was to evaluate the long-term outcome of ICD and CRT-D recipients. METHODS All patients who underwent ICD (n = 1729 [57%]) or CRT-D (n = 1326 [43%]) implantation at the Leiden University Medical Center since 1996 were evaluated. Follow-up visits were performed every 3-6 months, and events were registered. Cumulative incidence curves of device therapy and device-related complications were adjusted for the competing risk of all-cause mortality. RESULTS After a median follow-up of 5.1 years (25th-75th percentile 3.1-7.8 years), 842 patients (28%) died. The cumulative incidence of all-cause mortality was 49% (95% confidence interval [CI] 45%-54%) in ICD recipients after 12 years of follow-up and 55% (95% CI 52%-58%) in CRT-D recipients after 8 years of follow-up. A total of 1081 patients (35%) received appropriate defibrillator therapy. The cumulative incidence of appropriate therapy in ICD patients was 58% (95% CI 54%-62%) after 12 years of follow-up and 39% (95% CI 35%-43%) in CRT-D patients after 8 years of follow-up. Twelve-year cumulative incidences of adverse events were 20% (95% CI 18%-22%) for inappropriate shock, 6% (95% CI 5%-8%) for device-related infection, and 17% (95% CI 14%-21%) for lead failure. CONCLUSION After long-term follow-up of ICD (12 years) and CRT-D (8 years) recipients, 49% of ICD recipients and 55% of CRT-D recipients had died. Appropriate ICD therapy was received by the majority (58%) of ICD recipients and by almost 40% of CRT-D recipients.

How adequate are the current methods of lead extraction? A review of the efficiency and safety of transvenous lead extraction methods

Currently several extraction tools are available in order to allow safe and successful transvenous lead extraction (TLE) of pacemaker and ICD leads; however, no directives exist to guide physicians in their choice of extraction tools and approaches. To aim of the current review is to provide an overview of the success and complication rates of different extraction methods and tools available. A comprehensive search of all published literature was conducted in the databases of PubMed, Embase, Web of Science, and Central. Included papers were original articles describing a specific method of TLE and the corresponding success rates of at least 50 patients. Fifty-three studies were included; the majority (56%) utilized 2 (1-4) different venous extraction approaches (subclavian and femoral), the median number of extraction tools used was 3 (1-6). A stepwise approach was utilized in the majority of the studies, starting with simple traction which resulted in successful TLE in 7-85% of the leads. When applicable the procedure was continued with non-powered tools resulting in a successful extraction of 34-87% leads. Subsequently, powered tools were applied whereby success rates further increased to 74-100%. The final step in TLE was usually utilized by femoral snare leading to an overall TLE success rate of 96-100%. The median procedure-related mortality and major complication described were, respectively, 0% (0-3%) and 1% (0-7%) per patient. In conclusion, a stepwise extraction approach can result in a clinical successful TLE in up to 100% of the leads with a relatively low risk of procedure-related mortality and complications.

CT coronary angiography is feasible for the assessment of coronary artery disease in chronic dialysis patients, despite high average calcium scores.

Purpose Significant obstructive coronary artery disease (CAD) is common in asymptomatic dialysis patients. Identifying these high risk patients is warranted and may improve the prognosis of this vulnerable patient group. Routine catheterization of incident dialysis patients has been proposed, but is considered too invasive. CT-angiography may therefore be more appropriate. However, extensive coronary calcification, often present in this patient group, might hamper adequate lumen evaluation. The objective of this study was to assess the feasibility of CT-angiography in this patient group. Methods For this analysis all patients currently participating in the ICD2 trial (ISRCTN20479861), with no history of PCI or CABG were included. The major epicardial vessels were evaluated on a segment basis (segment 1–3, 5–8, 11 and 13) by a team consisting of an interventional and an imaging specialist. Segments were scored as not significant, significant and not interpretable. Results A total of 70 dialysis patients, with a mean age of 66±8 yrs and predominantly male (70%) were included. The median calcium score was 623 [79, 1619]. Over 90% of the analyzed segments were considered interpretable. The incidence of significant CAD on CT was 43% and was associated with cardiovascular events during follow-up. The incidence of cardiovascular events after 2-years follow-up: 36% vs. 0% in patients with no significant CAD (p<0.01). Conclusion Despite the high calcium scores CT-angiography is feasible for the evaluation of the extent of CAD in dialysis patients. Moreover the presence of significant CAD on CT was associated with events during follow-up.

Serum Cardiac Troponin-I is Superior to Troponin-T as a Marker for Left Ventricular Dysfunction in Clinically Stable Patients with End-Stage Renal Disease

Background Serum troponin assays, widely used to detect acute cardiac ischemia, might be useful biomarkers to detect chronic cardiovascular disease (CVD). Cardiac-specific troponin-I (cTnI) and troponin-T (cTnT) generally detect myocardial necrosis equally well. In dialysis patients however, serum cTnT levels are often elevated, unlike cTnI levels. The present study aims to elucidate the associations of cTnI and cTnT with CVD in clinically stable dialysis patients. Methods Troponin levels were measured using 5th generation hs-cTnT assays (Roche) and STAT hs-cTnI assays (Abbott) in a cohort of dialysis patients. Serum troponin levels were divided into tertiles with the lowest tertile as a reference value. Serum troponins were associated with indicators of CVD such as left ventricular mass index (LVMI), left ventricular ejection fraction (LVEF) and the presence of coronary artery disease (CAD). Associations were explored using regression analysis. Results We included 154 consecutive patients, 68±7 years old, 77% male, 70% hemodialysis. Median serum cTnT was 51ng/L (exceeding the 99th percentile of the healthy population in 98%) and median serum cTnI was 13ng/L (elevated in 20%). A high cTnI (T3) was significantly associated with a higher LVMI (Beta 31.60; p=0.001) and LVEF (Beta -4.78; p=0.005) after adjusting for confounders whereas a high serum cTnT was not. CAD was significantly associated with a high cTnT (OR 4.70 p=0.02) but not with a high cTnI. Unlike cTnI, cTnT was associated with residual renal function (Beta:-0.09; p=0.006). Conclusion In the present cohort, serum cTnI levels showed a stronger association with LVMI and LVEF than cTnT. However, cTnT was significantly associated with CAD and residual renal function, unlike cTnI. Therefore, cTnI seems to be superior to cTnT as a marker of left ventricular dysfunction in asymptomatic dialysis patients, while cTnT might be better suited to detect CAD in these patients.

Epicardial leads in adult cardiac resynchronization therapy recipients: a study on lead performance, durability, and safety.

BACKGROUND Transvenous left ventricular (LV) lead placement for cardiac resynchronization therapy-defibrillator (CRT-D) delivery is unsuccessful in 8% to 10% of cases. These patients might benefit from an epicardial lead. However, data on long-term epicardial lead performance are scarce. Furthermore, extracting an epicardial lead requires a rethoracotomy. OBJECTIVE The purpose of this study was to determine data on almost a decade of experience with epicardial leads and investigate the safety of partially leaving this lead in place after device infection. METHODS All adult patients receiving an epicardial lead (Medtronic CapSure Epi, model 4968) for CRT-D in the Leiden University Medical Center were included. Leads were implanted during a standalone procedure or in combination with other cardiothoracic procedures. Electrical lead parameters were assessed at implantation and every 6 months thereafter. In case of device infection the epicardial lead was cut off parasternal, just outside the thoracic cavity, leaving the distal part of the lead in place. RESULTS Two-hundred sixteen patients were included with a median follow-up of 3 years (25th-75th percentile 1.0-5.5). LV pacing threshold decreased within 6 months after implantation [1.1 V (95% confidence interval [CI] 0.9-1.2) vs 0.8 V (95% CI 0.7-0.9), P = .01] and stabilized thereafter. Mean LV electrogram was 15.2 ± 7.5 mV, and average lead impedance was 633.5 ± 174.0 Ω. Five-year cumulative incidence was 1.6% for lead failure and 9.6% for device infection. The retained epicardial lead caused skin erosion in 3 patients and fistula formation in 1. CONCLUSION This study demonstrates that epicardial LV leads have an excellent long-term performance. Partially retaining the lead after device infection was associated with a risk of reinfection with limited long-term clinical implications for the patient.

How to reduce sudden cardiac death in patients with renal failure

Prevention of sudden cardiac death (SCD) is an important target for improving survival in various patient groups and many prevention options have been evaluated. In the past decade several trials have documented beneficial effects for implantable cardioverter-defibrillator (ICD) implantation in patients surviving out-of-hospital cardiac arrest (secondary prevention) and in patients with diminished left ventricular function (primary prevention).1 However, within these patient groups a variety of comorbidities is present which might influence the benefit conferred by prophylactic ICD implantation. One of these comorbidities is chronic kidney disease (CKD), a condition that is highly prevalent among patients with a current ICD indication. CKD is of particular interest since this condition is associated with a substantial risk for non-arrhythmic death and this might negatively influence the beneficial effects of prophylactic ICD implantation. Accordingly this raises the question whether ICD implantation in these patients is appropriate for prevention of SCD or whether other more conservative treatment strategies are preferred with regard to safety and cost effectiveness. The mechanisms that underlie SCD in patients with CKD are complex and many factors have been associated with increasing the risk for SCD. Beside coronary artery disease (CAD), present in 80% of the patients dying from SCD, many other factors are believed to contribute to the development of SCD in patients with CKD which also might form therapeutic targets for preventing SCD in these patients. The key factors in the development of SCD, including CAD, will be discussed below and are summarised in table 1. View this table: Table 1 Mechanisms associated with sudden cardiac death in patients with chronic kidney disease ### Ischaemic heart disease CAD is highly prevalent among patients with CKD and is more severe compared to …

Republished: How to reduce sudden cardiac death in patients with renal failure.

Prevention of sudden cardiac death (SCD) is an important target for improving survival in various patient groups and many prevention options have been evaluated. In the past decade several trials have documented beneficial effects for implantable cardioverter-defibrillator (ICD) implantation in patients surviving out-of-hospital cardiac arrest (secondary prevention) and in patients with diminished left ventricular function (primary prevention).1 However, within these patient groups a variety of comorbidities is present which might influence the benefit conferred by prophylactic ICD implantation. One of these comorbidities is chronic kidney disease (CKD), a condition that is highly prevalent among patients with a current ICD indication. CKD is of particular interest since this condition is associated with a substantial risk for non-arrhythmic death and this might negatively influence the beneficial effects of prophylactic ICD implantation. Accordingly this raises the question whether ICD implantation in these patients is appropriate for prevention of SCD or whether other more conservative treatment strategies are preferred with regard to safety and cost effectiveness. The mechanisms that underlie SCD in patients with CKD are complex and many factors have been associated with increasing the risk for SCD. Beside coronary artery disease (CAD), present in 80% of the patients dying from SCD, many other factors are believed to contribute to the development of SCD in patients with CKD which also might form therapeutic targets for preventing SCD in these patients. The key factors in the development of SCD, including CAD, will be discussed below and are summarised in table 1. View this table: Table 1 Mechanisms associated with sudden cardiac death in patients with chronic kidney disease ### Ischaemic heart disease CAD is highly prevalent among patients with CKD and is more severe compared to …