David Duncker

Implantable defibrillator therapy for ventricular tachyarrhythmia in left ventricular assist device patients

Ventricular arrhythmias (VA) occur frequently after permanent left ventricular assist device (LVAD) implantation in end stage heart failure. Left ventricular assist device patients require rhythm control in contrast to patients with biventricular support. However, the rationale for implantable cardioverter‐defibrillator (ICD) utilization in LVAD patients remains unclear. This study investigated the safety and efficacy of primary prevention ICD therapy and the rate of appropriate ICD interventions in LVAD patients.

Risk for ventricular fibrillation in peripartum cardiomyopathy with severely reduced left ventricular function—value of the wearable cardioverter/defibrillator

The true incidence of life‐threatening ventricular tachyarrhythmic events and the risk of sudden cardiac death in the early stage of peripartum cardiomyopathy (PPCM) are still unknown. We aimed to assess the usefulness of the wearable cardioverter/defibrillator (WCD) to bridge a potential risk for life‐threatening arrhythmic events in patients with early PPCM, severely reduced left ventricular ejection fraction (LVEF) and symptoms of heart failure.

Avoiding Untimely Implantable Cardioverter/Defibrillator Implantation by Intensified Heart Failure Therapy Optimization Supported by the Wearable Cardioverter/Defibrillator-The PROLONG Study.

Background Optimal timing of implantation of an implantable cardioverter/defibrillator (ICD) after newly diagnosed heart failure is unclear given that late reverse remodelling may occur. We aimed to analyze left ventricular ejection fraction (LVEF) after diagnosis of an LVEF ≤35% during optimization of heart failure drug therapy. Methods and Results One hundred fifty‐six patients with newly diagnosed LVEF ≤35% receiving a wearable cardioverter/defibrillator (WCD) were analyzed. WCD was prescribed for 3 months until first re‐evaluation. Indications for prolongation of WCD wearing period instead of ICD implantation were: (1) LVEF at 3‐month visit 30% to 35%; (2) increase in LVEF of ≥5% compared to the last visit; and (3) nonoptimized heart failure medication. Mean LVEF was 24±7% at diagnosis and 39±11% at last follow‐up (mean, 12±10 months). Whereas 88 patients presented a primary preventive ICD indication (LVEF ≤35%) at 3‐month follow‐up, only 58 showed a persistent primary preventive ICD indication at last follow‐up. This delayed improvement in LVEF was related to nonischemic origin of cardiomyopathy, New York Heart Association functional class at baseline, heart rate, better LVEF after 3 months, and higher dosages of mineralocorticoid receptor antagonist. Twelve appropriate WCD shocks for ventricular tachycardia/ventricular fibrillation occurred in 11 patients. Two patients suffered from ventricular tachycardia/ventricular fibrillation beyond 3 months after diagnosis. Conclusions A relevant proportion of patients with newly diagnosed heart failure shows recovery of LVEF >35% beyond 3 months after initiation of heart failure therapy. To avoid untimely ICD implantation, prolongation of WCD period should be considered in these patients to prevent sudden cardiac death while allowing left ventricular reverse remodeling during intensified drug therapy.

Clinical relevance of slow ventricular tachycardia in heart failure patients with primary prophylactic implantable cardioverter defibrillator indication

AIMS Implantable cardioverter defibrillators (ICDs) have shown to reduce all-cause mortality in heart failure patients. In SCD-HeFT study, ICDs were programmed with a detection zone of ≥ 187 b.p.m. Thus, the incidence and clinical significance of slower ventricular tachycardias (VTs) in these patients remains largely unknown, though clinically important for device selection, programming, and follow-up. METHODS AND RESULTS We prospectively studied symptomatic heart failure patients with an indication for a primary prophylactic ICD with or without concomitant resynchronization therapy according to SCD-HeFT inclusion criteria. Devices were programmed to an additional monitor zone for slow VTs at heart rates 130-186 b.p.m. Two hundred consecutive patients (86% male) were followed for a mean of 509 ± 308 days. One hundred and thirty-seven patients (68.5%) were New York Heart Association class III, 75 patients (37.5%) were on cardiac resynchronization therapy, and 124 (62%) had ischaemic cardiomyopathy. We observed 473 VT episodes in 36 patients (18%) and 131 ventricular fibrillation episodes in 30 patients (15%). Ventricular tachycardia overall occurred in 40 patients (20%). The incidence of slow VTs was low in only 12 patients (6%). No patient with slow VT suffered from syncope, palpitation, or decompensation leading to hospitalization. We did not find any reliable predictor for increased long-term risk of slow VTs. CONCLUSION Incidence of slow VTs in a typical heart failure population with primary prophylactic ICD-implantation ± resynchronization therapy is very low. Slow VTs detected in the ICD monitor zone remained clinically asymptomatic. Thus, single chamber and atriobiventricular ICDs with a VT/ventricular fibrillation zone of ≥ 187 b.p.m. and one burst before shock delivery might be sufficient and pragmatic for the vast majority of these patients.

Subcutaneous Implantable Cardioverter-Defibrillator Shocks After Left Ventricular Assist Device Implantation

A 42-year-old man experiencing nonischemic cardiomyopathy with severely reduced left ventricular function and advanced heart failure met the criteria for primary prophylactic implantation of an implantable cardioverter-defibrillator (ICD). A subcutaneous ICD (S-ICD; EMBLEM; Boston Scientific, Marlborough, MA) was implanted at a secondary center in November 2015 with the lead (3401; Boston Scientific) tunnelled in left parasternal position. Before implantation, surface ECG screening was performed following the manufacturer’s instructions. A few weeks later, the patient was transferred to Hannover Medical School because of heart failure deterioration (New York Heart Association class IV). After careful evaluation, a continuous-flow left ventricular assist device (LVAD; HeartMate 3; Thoratec, Pleasanton, CA) was implanted using conventional sternotomy.1 Approximately 1 hour after LVAD implantation, the patient received 31 S-ICD shocks. The device was immediately deactivated. Interrogation of the S-ICD revealed normal sinus rhythm during the shocks. However, R waves were diminished and superimposed by electric …

Stable Cystatin C Serum Levels Confirm Normal Renal Function in Patients With Dronedarone-Associated Increase in Serum Creatinine

Dronedarone is a new antiarrhythmic drug for patients with nonpermanent atrial fibrillation (AF). A relatively consistent finding in all trials studying dronedarone was a moderate but significant elevation of serum creatinine. Since dronedarone competes for the same organic cation transporter in the distal renal tubule with creatinine, serum creatinine and its derived estimated glomerular filtration rate might not reflect true renal function in patients on dronedarone. We therefore investigated alternative markers for renal function in these patients. We prospectively included 20 patients with nonpermanent AF in whom dronedarone 400 mg twice daily was started. Patients had normal renal function and serum creatinine; serum cystatin C and creatinine clearance were measured before treatment and 10 and 90 days after treatment started. Mean serum creatinine level for all 20 patients at baseline (day 0) was 84.55 ± 12.14 and 87.8 ± 17.59 µmol/L on day 10. This slight increase in all patients was not significant. Patients were now divided into the predefined groups of “increased creatinine” (increase in serum creatinine level > 1 standard deviation) and “not increased creatinine.” Patients with increased creatinine levels (n = 5) showed a significant elevation of serum creatinine levels from day 0 to day 10 (82.4 ± 9.18 to 104.4 ± 12.74 µmol/L; P = .003), whereas change in serum creatinine levels in the not increased creatinine group (n = 15) was not significant. Serum cystatin C levels remained stable in both of these groups (increased creatinine group: 0.76 ± 0.08 to 0.78 ± 0.08 mg/L; P = .65; not increased creatinine group: 0.77 ± 0.108 to 0.77 ± 0.107 mg/L; P = .906). In conclusion, cystatin C represents an easily available and reliable biomarker for estimation of true renal function in patients on dronedarone treatment.

Ablation of Typical Right Atrial Flutter in Patients with Pulmonary Hypertension

BACKGROUND RF ablation for cavotricuspid isthmus (CTI) dependent flutter is an established therapy. Right atrial hypertrophy and enlargement are associated with the occurrence of cavotricuspid isthmus dependent flutter. Therefore, patients with pulmonary hypertension (PAH) are prone to atrial arrhythmias like cavotricuspid isthmus dependent flutter. However, the influence of PAH on typical atrial flutter ablation procedure has not been systematically examined. METHODS In a retrospective single-centre analysis data of patients undergoing an ablation procedure for cavotricuspid isthmus dependent flutter between January 2007 and October 2009 at Hannover Medical School, Germany were analysed. Only procedures performed by experienced electrophysiologists with an 8mm RF-ablation catheter were included. Data for 196 patients were analysed. Thirty-eight patients were identified with PAH and were compared to 158 patients without PAH for procedural ablation parameters, procedure time, ablation time, ablation points and fluoroscopy time. RESULTS A bidirectional block of the CTI was achieved in all patients. Patients with severe PAH had a significantly longer procedure time (78±40 min vs. 62±29 min; p=0.033), total ablation time (20±11 min vs. 15±9 min; p=0.02) and more ablation lesions (26±16 vs. 19±12; p=0.018) as compared to patients without PAH. CONCLUSION Cavotricuspid isthmus dependent flutter ablation in patients with PAH is associated with longer procedure duration and a greater amount of cumulative tissue ablation needed to achieve bidirectional block of the CTI compared to patients without pulmonary hypertension.

Ventricular arrhythmias in patients with newly diagnosed nonischemic cardiomyopathy: Insights from the PROLONG study: Ventricular arrhythmias in newly diagnosed non-ischemic cardiomyopathy

Patients with nonischemic cardiomyopathy (NICM) reportedly have low incidence of appropriate shocks from wearable cardioverter‐defibrillators (WCDs). A recent study questions the benefit from primary preventive implantation of implantable cardioverter‐defibrillators in NICM. We therefore analyzed a subgroup of patients with NICM from the PROLONG study.

Cardiac resynchronization therapy improves psycho-cognitive performance in patients with heart failure

BACKGROUND Reduced cognitive performance and high prevalence of depression have been reported in patients with congestive heart failure (CHF) and severe left ventricular dysfunction. However, effects of contemporary device therapy on cognitive performance and depression symptoms have not been studied thoroughly. METHODS Seventy-four consecutive CHF patients-45 receiving a biventricular defibrillator (CRT-D) and 29 receiving an implantable single or dual-chamber defibrillator (ICD) as a control group-were enrolled in this investigator-initiated, prospective, controlled, and investigator-blinded study. A set of neuropsychological tests (mini-mental state examination, DemTect, age-concentration test, and Beck depression inventory) was performed before, at 3 and at 6 months after device implantation. RESULTS DemTect-score improved significantly (F = 7.8; P = 0.007) after CRT-D-implantation compared with ICD. Age-concentration test revealed better concentration ability after CRT-D-implantation (F = 8.3; P = 0.005) compared with ICD. Under CRT-D mini-mental state examination showed a significant improvement (F = 4.2; P = 0.043). CRT with defibrillator therapy also improved depression revealed by beck depression inventory (F = 14.7; P< 0.001) compared with ICD. CONCLUSION This prospective study is the first to demonstrate psycho-cognitive improvement by resynchronization therapy in CHF patients with severe left ventricular dysfunction. In contrast to ICD therapy, the beneficial effect of CRT-D on psycho-cognitive performance might be attributed to improved cardiac function and haemodynamics.

Association of left atrial low-voltage area and thromboembolic risk in patients with atrial fibrillation

Aims Atrial fibrillation (AF) is associated with thromboembolic events. Currently, the CHA2DS2-VASc score is recommended for thromboembolic risk stratification in non-valvular AF patients. However, recent data suggested a potential role of atrial remodelling on thromboembolism. This study aimed to assess the association between left atrial low-voltage area (LVA) and history of clinical manifest as well as subclinical silent cerebral ischaemia (SCI) in AF patients. Methods and results Two-hundred patients [64 ± 10.5 years, 75 women (37.5%)] with symptomatic paroxysmal (n = 88, 44%) or persistent AF undergoing pulmonary vein isolation (PVI) were prospectively enrolled. Left atrial LVA (bipolar voltage < 0.5mV) was evaluated by intra-procedural mapping (>300 points per patient) during sinus rhythm. Cerebral delayed-enhancement magnetic resonance imaging was performed after PVI for detection of pre-existing procedural-independent SCI. Over all, 17 patients (8.5%) had previous history of stroke. Pre-existing SCIs were detected in 135 patients (67.5%). Patients with previous stroke (4.0 ± 1.5 vs. 2.1 ± 1.3, P < 0.0001) and pre-existing SCI (2.7 ± 1.3 vs. 1.5 ± 1.4, P < 0.0001) had a significantly higher CHA2DS2-VASc score. LVA was significantly larger in patients with previous stroke (12.5 ± 8.5% vs. 3.4 ± 5.4%, P < 0.0001) as well as pre-existing SCI (5.8 ± 6.9% vs. 0.8 ± 1.7%, P < 0.0001). Multivariate regression analysis revealed that LVA was independently associated with the presence of SCI [hazard ratio (HR) per 1% LVA 1.13 (1.06-1.22), P = 0.0003] and history of stroke [HR per 1% LVA 1.36 (1.19-1.60), P < 0.0001] after adjustment of CHA2DS2-VASc score. Conclusion Left atrial LVA is associated with history of stroke and SCI in patients with non-valvular AF and might improve thromboembolic risk stratification after confirmation of its predictive value in future studies.