Association of Remote Monitoring With Survival in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy: Retrospective Observational Study.

BACKGROUND: Remote monitoring is an established, guideline-recommended technology with unequivocal clinical benefits; however, its ability to improve survival is contradictory. OBJECTIVE: The aim of our study was to investigate the effects of remote monitoring on mortality in an optimally treated heart failure patient population undergoing cardiac resynchronization defibrillator therapy (CRT-D) implantation in a large-volume tertiary referral center. METHODS: The population of this single-center, retrospective, observational study included 231 consecutive patients receiving CRT-D devices in the Medical Centre of the Hungarian Defence Forces (Budapest, Hungary) from January 2011 to June 2016. Clinical outcomes were compared between patients on remote monitoring and conventional follow-up. RESULTS: The mean follow-up time was 28.4 (SD 18.1) months. Patients on remote monitoring were more likely to have atrial fibrillation, received heart failure management at our dedicated heart failure outpatient clinic more often, and have a slightly lower functional capacity. Crude all-cause mortality of remote-monitored patients was significantly lower compared with patients followed conventionally (hazard ratio [HR] 0.368, 95% CI 0.186-0.727, P=.004). The survival benefit remained statistically significant after adjustment for important baseline parameters (adjusted HR 0.361, 95% CI 0.181-0.722, P=.004). CONCLUSIONS: In this single-center, retrospective study of optimally treated heart failure patients undergoing CRT-D implantation, the use of remote monitoring systems was associated with a significantly better survival rate.

Physical activity detection in patients with intracardiac leadless pacemaker.

INTRODUCTION: The Micra Transcatheter Pacing System provides a rate adaptive pacing using an individually programmable three-axis accelerometer. We evaluated the short- and mid-term performance of the Micra activity sensor by testing all three available activity vectors during the exercise tests. METHODS AND RESULTS: Implantation and follow-up data were prospectively collected from the patients undergoing Micra implantation at our institution. Patients underwent a 5-minute exercise test for each vector at predischarge (initial testing) and at scheduled in-office visits (repeat testing). On the basis of measurements of activity counts during the test, vectors were categorized to be adequate (excellent or acceptable) or poor. A total of 278 tests with 818 vector measurements were analyzed in 51 patients during follow-up (median duration was 18 months). Initial testing revealed the adequate quality of the nominal Vector 1 in 74.5% of the patients. Upon repeated testing at subsequent in-office visits, Vectors 1 and 3 were comparable (adequate quality in 64.7% vs 68.6% of the patients; P = 0.65) but better compared with Vector 2 (51.0%; P = 0.10 vs Vector 1, P = 0.01 vs Vector 3). In a subgroup of 45 patients programmed to VVIR mode, Vector 1 was selected in 46.7% of the patients after the initial test (Vector 2, 8.9%; Vector 3, 44.4%). Vector change was performed in 10 patients (22.2%) following repeated tests within 3 months of postimplantation. CONCLUSION: The three-axis accelerometer-based rate adaptive pacing feature proved to be feasible after manual selection of an adequate activity vector. Vector testing in Micra patients with chronotropic incompetence appears to be beneficial compared with the use of nominal Vector 1.

Needle aspiration for treating iatrogenic pneumothorax after cardiac electronic device implantation: a pilot study.

PURPOSE: Pneumothorax (PTX) following cardiac implantable electronic device procedures is traditionally treated with chest tube drainage (CTD). We hypothesized that, in a subset of patients, the less invasive needle aspiration (NA) may also be effective. We compared the strategy of primary NA with that of primary CTD in a single-center observational study. METHODS: Of the 970 procedures with subclavian venous access between January 2016 and June 2018, 23 patients had PTX requiring intervention. Beginning with March 2017, the traditional primary CTD (9 cases) has been replaced by the "NA first" strategy (14 patients). Outcome measures were procedural success rate and duration of hospitalization evaluated both as time to event (log-rank test) and as a discrete variable (Wilcoxon-Mann-Whitney test). RESULTS: Needle aspiration was successful in 8/14 (57.1%) of the cases (95% CI 28.9-82.3%), whereas PTX resolved in all patients after CTD was 9/9 (100%, 95% CI 66.4-100.0%, p = 0.0481). Regarding length of hospital stay, intention to treat time to event analysis showed no difference between the two approaches (p = 0.73). Also, the median difference was not statistically significant (- 2.0 days, p = 0.17). In contrast, per protocol evaluation revealed reduced risk of prolonged hospitalization for NA patients (p = 0.0025) with a median difference of - 4.0 days (p = 0.0012). Failure of NA did not result in a meaningful delay in discharge timing as median difference was 1.5 days (p = 0.28). CONCLUSIONS: Our data suggest that in a number of patients iatrogenic PTX may be successfully treated with NA resulting in shorter hospitalization without the risk of meaningful discharge delay in unsuccessful cases.

The impact of serum concentration-guided digoxin therapy on mortality of heart failure patients: A long-term follow-up, propensity-matched cohort study.

BACKGROUND: Recently published studies suggested that digoxin may increase mortality in heart failure with reduced ejection fraction (HFrEF). However, in the vast majority of former trials serum digoxin concentration (SDC) was not measured and therapy was not SDC-guided. AIM: To assess the impact of SDC-guided digoxin therapy on mortality in HFrEF patients. METHODS: Data of 580 HFrEF patients were retrospectively analyzed. In patients on digoxin, SDC was measured every 3 months and digoxin dosage was SDC-guided (target SDC: 0.5-0.9 ng/mL). All-cause mortality of digoxin users and nonusers was compared after propensity score matching (PSM). RESULTS: After 7.1 ± 4.7 years follow-up period (FUP) all-cause mortality of digoxin users (n = 180) was significantly higher than nonusers (n = 297) (propensity-adjusted HR = 1.430; 95% CI = 1.134-1.804; P = .003). Patients having SDC of 0.9 to 1.1 ng/mL (n = 60) or > 1.1 ng/mL (n = 44) at any time during the FUP had an increased risk of all-cause mortality (HR = 1.750; 95% CI = 1.257-2.436, P = .001 and HR = 1.687; 95% CI = 1.153-2.466, P = .007), while patients having a maximal SDC < 0.9 ng/mL (n = 76) had similar mortality risk (HR = 1.139; 95% CI = 0.827-1.570, P = .426), compared to digoxin nonusers. CONCLUSIONS: According to our propensity-matched analysis, SDC-guided digoxin therapy was associated with increased all-cause mortality in optimally treated HFrEF patients, especially with SDC ≥0.9 ng/mL. These results reinforce the expert opinion that digoxin in HFrEF can only be used among carefully selected patients with close SDC monitoring.

Effects of implantation of quadripolar left ventricular leads on CRT response.

BACKGROUND: The use of quadripolar (QP) left ventricular leads for cardiac resynchronization therapy (CRT) is intended to improve outcomes compared with conventional bipolar leads (BP). Hence, the number of implanted quadripolar CRT systems is increasing despite limited long-term data. PURPOSE: The aim of this study is to evaluate clinical response and long-term outcomes of CRT recipients who were implanted with quadripolar versus bipolar left ventricular leads. METHODS: Data from consecutive patients receiving a CRT defibrillator in one German and one Hungarian tertiary referral center were retrospectively collected. Long-term survival and response to CRT were analyzed. RESULTS: A total of 536 patients with structural heart disease and a mean left ventricular ejection fraction (LVEF) of 25% received a CRT defibrillator (CRT-D) system for primary (79%) or secondary (21%) prevention of sudden death. Comorbidities did not differ significantly between patients receiving a QP (n = 123) or a BP lead (n = 413). Procedure (101 vs. 120 min) and fluoroscopy times (14 vs. 20 min) were shorter in patients implanted with QP compared with BP (both p < 0.001). At 6 months follow-up, QP patients were more likely to respond to CRT measured as improvement in the New York Heart Association (NYHA) functional class (77% vs. 63%; p < 0.001). Use of QP left ventricle/left ventricular (LV) leads was associated with greater reduction in QRS duration compared with patients implanted with BP LV leads (- 21 ± 30 vs. - 8 ± 35 ms, p = 0.004). Mortality was not significantly different between patients with QP and patients with BP LV leads at a mean follow-up of 39 ± 31 months. CONCLUSION: Implantation of quadripolar left ventricular leads was associated with better CRT response compared with bipolar left ventricular leads.

Risk of cardiac arrhythmias after electrical accident: a single-center study of 480 patients.

OBJECTIVE: Patients with electrical injury are considered to be at high risk of cardiac arrhythmias. Due to the small number of studies, there is no widely accepted guideline regarding the risk assessment and management of arrhythmic complications after electrical accident (EA). Our retrospective observational study was designed to determine the prevalence of ECG abnormalities and cardiac arrhythmias after EA, to evaluate the predictive value of cardiac biomarkers for this condition and to assess in-hospital and 30-day mortality. METHODS: Consecutive patients presenting after EA at the emergency department of our institution between 2011 and 2016 were involved in the current analysis. ECG abnormalities and arrhythmias were analyzed at admission and during ECG monitoring. Levels of cardiac troponin I, CK and CK-MB were also collected. In-hospital and 30-day mortality data were obtained from hospital records and from the national insurance database. RESULTS: Of the 480 patients included, 184 (38.3%) had suffered a workplace accident. The majority of patients (96.2%) had incurred a low-voltage injury (< 1000 V). One hundred and four (21.7%) patients had a transthoracic electrical injury while 13 (2.7%) patients reported loss of consciousness. The most frequent ECG disorders at admission were sinus bradycardia (< 60 bpm, n = 50, 10.4%) and sinus tachycardia (> 100 bpm, n = 21, 4.4%). Other detected arrhythmias were as follows: newly diagnosed atrial fibrillation (n = 1); frequent multifocal atrial premature complexes (n = 1); sinus arrest with atrial escape rhythm (n = 2); ventricular fibrillation terminated out of hospital (n = 1); ventricular bigeminy (n = 1); and repetitive nonsustained ventricular tachycardia (n = 1). ECG monitoring was performed in 182 (37.9%) patients for 12.7 ± 7.1 h at the ED. Except for one case with regular supraventricular tachycardia terminated via vagal maneuver and one other case with paroxysmal atrial fibrillation, no clinically relevant arrhythmias were detected during the ECG monitoring. Cardiac troponin I was measured in 354 (73.8%) cases at 4.6 ± 4.3 h after the EA and was significantly elevated only in one resuscitated patient. CK elevation was frequent, but CK-MB was under 5% in all patients. Both in-hospital and 30-day mortality were 0%. CONCLUSIONS: Most of cardiac arrhythmias in patients presenting after EA can be diagnosed by an ECG on admission, thus routine ECG monitoring appears to be unnecessary. In our patient cohort cardiac troponin I and CK-MB were not useful in risk assessment after EA. Late-onset malignant arrhythmias were not observed.

ICD lead type and RV lead position in CRT-D recipients.

BACKGROUND: Data on preferred ICD lead type and optimal RV lead position in patients undergoing CRT-D implantation are limited. OBJECTIVES: To compare dual- versus single-coil ICD leads and non-apical versus apical RV lead position and their impact on clinical parameters and survival in CRT-D recipients. METHODS: A total of 563 consecutive patients with advanced heart failure and indication for CRT-D implantation were enrolled in two European tertiary centers. Endpoints were improvement in NYHA functional class, changes in echo- and electrocardiographic parameters, and all-cause and cardiovascular mortality. RESULTS: In this retrospective analysis, a total of 313 (56%) dual- and 250 (44%) single-coil ICD leads were used. RV leads were placed non-apically in 262 (47%) and apically in 296 (53%) patients, respectively. Over a mean follow-up of 41 ± 34 months, all-cause mortality and cardiovascular mortality were similar for patients with dual- versus single-coil ICD lead (adjusted HR 0.81, 95% CI 0.58-1.12 and aHR 1.22, 95% CI 0.73-2.04) and non-apical versus apical RV lead position (aHR 0.98, 95% CI 0.71-1.36 and aHR 0.76, 95% CI 0.44-1.31). Non-apical RV lead position was associated with greater reduction in QRS duration after CRT implantation (- 14.4 ± 32.1 vs. - 4.3 ± 34.3 ms, p < 0.001). CONCLUSIONS: We found no association between ICD lead type or RV lead position and outcomes in CRT-D recipients. Non-apical RV lead position was associated with larger reduction in QRS duration.

Refined heart failure detection algorithm for improved clinical reliability of OptiVol alerts in CRT-D recipients.

BACKGROUND: The reliability of intrathoracic impedance monitoring for prediction of heart failure (HF) by implantable cardiac devices is controversial. Despite using additional device-based parameters described in the PARTNERS HF study, such as new onset of arrhythmias, abnormal autonomics, low biventricular pacing rate or patient activity level, the predictive power of device diagnostic algorithm is still in doubt. The objective of this study was to compare the device diagnostic algorithm described in the PARTNERS HF study to a newly developed algorithm applying refined diagnostic criteria. METHODS: Fourty two patients were prospectively enrolled who had been implanted with an intrathoracic impedance and remote monitoring capable implantable cardiac defibrillator with a cardiac resychroniza-tion therapy (CRT-D) device in this observational study. If a remote OptiVolTM alert occurred, patients were checked for presence of HF symptoms. A new algorithm was derived from the original PARTNERS HF criteria, considering more sensitive cut-offs and changes of patterns of the device-based parameters. RESULTS: During an average follow-up of 38 months, 722 remote transmissions were received. From the total of 128 transmissions with OptiVol alerts, 32 (25%) corresponded to true HF events. Upon multivariate discriminant analysis, low patient activity, high nocturnal heart rate, and low CRT pacing (< 90%) proved to be independent predictors of true HF events (all p < 0.01). Incorporating these three refined criteria in a new algorithm, the diagnostic yield of OptiVol was improved by increasing specific-ity from 37.5% to 86.5%, positive predictive value from 34.1% to 69.8% and area under the curve from 0.787 to 0.922 (p < 0.01), without a relevant loss in sensitivity (96.9% vs. 93.8%). CONCLUSIONS: A refined device diagnostic algorithm based on the parameters of low activity level, high nocturnal heart rate, and suboptimal biventricular pacing might improve the clinical reliability of OptiVol alerts.

Ventricular rate stabilization for treatment of recurrent VT.

A patient with ischaemic cardiomyopathy received a secondary prevention VVI implantable cardioverter-defibrillator (ICD) after an episode of sustained ventricular tachycardia (VT). Because of recurrent VTs transmitted via CareLink, medical therapy was optimized and VT ablation was performed. Subsequently, a fast VT with a typical short-long-short initiation developed. In addition, there was an increasing need for ventricular pacing due to sinus bradycardia. This new type of VT could be successfully dealt with by upgrading to DDD ICD and activating the Ventricular Rate Stabilization algorithm.

Effect of cardiac resynchronization therapy with implantable cardioverter defibrillator versus cardiac resynchronization therapy with pacemaker on mortality in heart failure patients: results of a high-volume, single-centre experience.

AIMS: There are limited and contradictory data on the effects of CRT with implantable cardioverter defibrillator (CRT-D) on mortality as compared with CRT with pacemaker (CRT-P). METHODS AND RESULTS: We evaluated the long-term outcome of patients implanted with a CRT-D or CRT-P device in our high-volume single-centre experience. Data on all-cause mortality were derived from clinic visits and the Hungarian National Healthcare Fund Death Registry. Kaplan-Meier survival analyses and multivariate Cox regression models were used to evaluate all-cause mortality in patients with CRT-D vs. CRT-P, stratified by the aetiology of cardiomyopathy. From 2000 to 2011, 1122 CRT devices, 693 CRT-P (LVEF 28.2 ± 7.4%) and 429 CRT-D (LVEF 27.6 ± 6.4%), were implanted at our centre. During the median follow-up of 28 months, 379 patients died from any cause, 250 patients (36%) with an implanted CRT-P and 129 patients (30%) with an implanted CRT-D. There was no evidence of mortality benefit in patients implanted with a CRT-D compared with a CRT-P in the total cohort [hazard ratio (HR) 0.98, 95% confidence interval (CI) 0.73-1.32, P = 0.884]. In patients with ischaemic cardiomyopathy, CRT-D treatment was associated with a significant 30% risk reduction in all-cause mortality compared with an implanted CRT-P (HR 0.70, 95% CI 0.51-0.97, P = 0.03). In non-ischaemic patients, there was no mortality benefit of CRT-D over CRT-P (HR 0.98, 95% CI 0.73-1.32, P = 0.894, interaction P-value = 0.15). CONCLUSIONS: In heart failure patients with ischaemic cardiomyopathy, CRT-D was associated with a mortality benefit compared with CRT-P, but no benefit of CRT-D over CRT-P in mortality was observed in non-ischaemic cardiomyopathy.