Device-detected atrial sensing amplitudes as a marker of increased risk for new onset and progression of atrial high-rate episodes.

BACKGROUND: Atrial high-rate episodes (AHREs) are frequent in patients with cardiac implantable electronic devices. A decrease in device-detected P-wave amplitude may be an indicator of periods of increased risk of AHRE. OBJECTIVE: The objective of this study was to assess the association between P-wave amplitude and AHRE incidence. METHODS: Remote monitoring data from 2579 patients with no history of atrial fibrillation (23% pacemakers and 77% implantable cardioverter-defibrillators, of which 40% provided cardiac resynchronization therapy) were used to calculate the mean P-wave amplitude during 1 month after implantation. The association with AHRE incidence according to 4 strata of daily burden duration (≥15 minutes, ≥6 hours, ≥24 hours, ≥7 days) was investigated by adjusting the hazard ratio with the CHA2DS2-VASc score. RESULTS: The adjusted hazard ratio for 1-mV lower mean P-wave amplitude during the first month increased from 1.10 (95% confidence interval [CI], 1.05-1.15; P < .001) to 1.18 (CI, 1.09-1.28; P < .001) with AHRE duration strata from ≥15 minutes to ≥7 days independent of the CHA2DS2-VASc score. Of 871 patients with AHREs, those with 1-month P-wave amplitude <2.45 mV had an adjusted hazard ratio of 1.51 (CI, 1.19-1.91; P = .001) for progression of AHREs from ≥15 minutes to ≥7 days compared with those with 1-month P-wave amplitude ≥2.45 mV. Device-detected P-wave amplitudes decreased linearly during the 1 year before the first AHRE by 7.3% (CI, 5.1%-9.5%; P < .001 vs patients without AHRE). CONCLUSION: Device-detected P-wave amplitudes <2.45 mV were associated with an increased risk of AHRE onset and progression to persistent forms of AHRE independent of the patient's risk profile.

The Impact of COVID-19 Outbreak on Syncope Units Activities in Italy: A Report from the Italian Multidisciplinary Working Group on Syncope (GIMSI).

The aim of our study was to evaluate the impact of the COVID-19 outbreak on Syncope Units (SUs) Activities in Italy. Methods: Data about types of SU activities and admissions were obtained from 10 SUs throughout Italy, certified by the Italian Multidisciplinary Working Group on Syncope (GIMSI), from 10 March 2020 to 31 December 2020 and compared with the same time frame in 2019. Results: A remarkable reduction in overall non-invasive diagnostic tests (-67%; p < 0.001) and cardiac invasive procedure. Elective cardiac pacing procedures disclosed a significant decrease (-62.7%; p < 0.001); conversely, the decrease of urgent procedures was not significant (-50%; p = 0.08). There was a significantly increased rate of patients who underwent both telemedicine follow-up visits (+225%, p < 0.001) and cardiac implantable electronic devices (CIEDs) remote monitoring follow-up visits (+100%; p < 0.001). Conclusion: The COVID-19 outbreak was associated with a remarkable decrease in all clinical activities of Syncope Units in Italy, including both non-invasive tests and cardiac invasive procedures; conversely, a significant increase in telehealth activities was shown.

Heart failure hospitalizations and costs in ICD/CRT-D recipients following replacement or upgrade: the DECODE registry.

AIMS: The aim of this study is to report heart failure hospitalization (HFH) rates and associated costs within 12 months following implantable cardioverter defibrillator (ICD)/cardiac resynchronization therapy defibrillator (CRT-D) device replacement or upgrade from ICD to CRT-D. METHODS AND RESULTS: The DEtect long-term COmplications after icD rEplacement (DECODE) was a prospective, single-arm, multicentre cohort study that explored complications in ICD/CRT-D recipients. All clinical and survival data at 12 months were prospectively analysed. For each adjudicated HFH, admission and discharge dates and ICD-9-CM diagnosis and procedure codes were recorded. The reimbursement for each HFH was calculated for each diagnosis-related group code. Between 2013 and 2015, 983 patients (mean age 71 years, male 76%, mean left ventricular ejection fraction 35%, and New York Heart Association Class I/II 75.6%) were enrolled. Patients underwent device replacement (900; 91.6%, 446 ICD/454 CRT-D) or ICD upgrade to CRT-D (83; 8.4%). Post-replacement hospitalizations occurred in 220 patients, with the primary discharge diagnosis identifying cardiovascular causes in 175 patients (80%). Fifty-five (5.6%) patients experienced at least one HFH. Overall, 91 HFH events occurred (9.6% event rate, 95% confidence interval: 7.7-11.7) in 70 patients; 66 (6.7%) patients died, 40 (60.6%) of cardiovascular causes. The HFH rate was significantly higher following upgrades, and the occurrence of HFH was associated with an 11-fold increased mortality risk (95% confidence interval: 5.9-20.5, P < 0.0001). Medical diagnosis-related group accounted for 91.2% of HFH; the mean cost per HFH was €5662 ± 9497, and the mean cost per patient was €9369 ± 12 687. On multivariate analysis, predictors of HFH were atrial fibrillation, chronic kidney disease, and all-cause hospitalization within 30 days prior to the procedure. CONCLUSIONS: In the DECODE registry, HFH and mortality rates in the year following ICD/CRT-D replacement or upgrade were low. In this particular subset, underlying cardiac disease was the main driver of HFH, mortality, and higher healthcare expenditures.

The role of atrial sensing for new-onset atrial arrhythmias diagnosis and management in single-chamber implantable cardioverter-defibrillator recipients: Results from the THINGS registry.

INTRODUCTION: Atrial tachycardia/fibrillation (AT/AF) episodes are common in implantable cardioverter-defibrillator (ICD) recipients and can be undetected by standard single-chamber devices. This study aims to explore whether a single-lead ICD with an atrial dipole (ICD DX; BIOTRONIK SE & Co, Berlin, Germany) could improve the AT/AF diagnosis and management as compared to standard ICD (ICD VR). METHODS AND RESULTS: We selected patients without AT/AF history from the THINGS registry which included consecutive patients implanted with ICD for standard indications. The ICD VR and the ICD DX groups included 236 (62.8%) and 140 (37.2%) patients, respectively, and had no significant differences in baseline characteristics. During a median follow-up of 27 months, there were 7 AT/AF diagnoses in the ICD VR and 18 in the ICD DX group. The 2-year incidence of AT/AF diagnosis was 3.6% (95% confidence interval [CI]: 1.6%-9.6%) for the ICD VR and 11.4% (95% CI: 6.8%-18.9%) for the ICD DX group (adjusted hazard ratio [HR]: 3.85 [95% CI: 1.58-9.41]; P = .003). Initiation of oral anticoagulation (OAC) due to AT/AF diagnosis was reported in 15 patients. The 2-year incidence of OAC onset was 3.6% (95% CI: 1.6%-7.8%) for the ICD VR and 6.3% (95% CI: 3.0%-12.7%) for ICD DX group (adjusted HR: 1.99 [95% CI: 0.72-5.56]; P = .184). CONCLUSION: We observed that atrial sensing capability in single-chamber ICD patients without evidence of atrial arrhythmias at implant is associated with a greater likelihood of detecting AT/AF episodes. The management of these diagnosed arrhythmias often led to clinical interventions, mainly represented by initiation of OAC therapy.

Impact of pacemaker longevity on expected device replacement rates: Results from computer simulations based on a multicenter registry (ESSENTIAL).

BACKGROUND: The rate of device replacement in pacemaker recipients has not been investigated in detail. HYPOTHESIS: Current pacemakers with automatic management of atrial and ventricular pacing output provide sufficient longevity to minimize replacement rate. METHODS: We considered a cohort of 542 pacemaker patients (age 78 ± 9 years, 60% male, 71% de-novo implants) and combined 1-month projected device longevity with survival data and late complication rate in a 3-state Markov model tested in several Monte Carlo computer simulations. Predetermined subgroups were: age < or ≥ 70; gender; primary indication to cardiac pacing. RESULTS: At the 1-month follow-up the reported projected device longevity was 153 ± 45 months. With these values the proportion of patients expected to undergo a device replacement due to battery depletion was higher in patients aged <70 (49.9%, range 32.1%-61.9%) than in age ≥70 (24.5%, range 19.9%-28.8%); in women (39.9%, range 30.8%-48.1%) than in men (32.0%, range 24.7%-37.5%); in sinus node dysfunction (41.5%, range 30.2%-53.0%) than in atrio-ventricular block (33.5%, range 27.1-38.8%) or atrial fibrillation with bradycardia (27.9%, range 18.5%-37.0%). The expected replacement rate was inversely related to the assumed device longevity and depended on age class: a 50% increase in battery longevity implied a 5% reduction of replacement rates in patients aged ≥80. CONCLUSIONS: With current device technology 1/4 of pacemaker recipients aged ≥70 are expected to receive a second device in their life. Replacement rate depends on age, gender, and primary indication owing to differences in patients' survival expectancy. Additional improvements in device service time may modestly impact expected replacement rates especially in patients ≥80 years.

Automatic management of atrial and ventricular stimulation in a contemporary unselected population of pacemaker recipients: the ESSENTIAL Registry.

AIMS: We investigated the applicability of the Ventricular Capture Control (VCC) and Atrial Capture Control (ACC) algorithms for automatic management of cardiac stimulation featured by Biotronik pacemakers in a broad, unselected population of pacemaker recipients. METHODS AND RESULTS: Ventricular Capture Control and Atrial Capture Control were programmed to work at a maximum adapted output voltage as 4.8 V in consecutive recipients of Biotronik pacemakers. Ambulatory threshold measurements were made 1 and 12 months after pacemaker implant/replacement in all possible pacing/sensing configurations, and were compared with manual measurements. Among 542 patients aged 80 (73-85) years, 382 had a pacemaker implant and 160 a pacemaker replacement. Ventricular Capture Control could work at long term in 97% of patients irrespectively of pacing indication, lead type, and lead service life, performance being superior with discordant pacing/sensing configurations. Atrial Capture Control could work in 93% of patients at 4.8 V maximum adapted voltage and at any pulse width, regardless of pacing indication, lead type, and service life. At 12-month follow-up, a ventricular threshold increase ≥1.5 V had occurred in 4.4% of patients uneventfully owing to VCC functioning. Projected pacemaker longevity at 1 month was strongly correlated with the 12-month estimate, and exceeded 13 years in >60% of patients. CONCLUSION: These algorithms for automatic management of pacing output ensure patient safety in the event of a huge increase of pacing threshold, while enabling maximization of battery longevity. Their applicability is quite broad in an unselected pacemaker population irrespectively of lead choice and service of life.

Cardiac device therapy in patients with left ventricular dysfunction and heart failure: 'real-world' data on long-term outcomes (mortality, hospitalizations, days alive and out of hospital).

BACKGROUND: The impact on long-term outcomes of implantable cardioverter defibrillators (ICDs) and biventricular defibrillators for cardiac resynchronization (CRT-D) devices in 'real world' patients with heart failure (HF) needs to be assessed in terms of clinical effectiveness. METHODS AND RESULTS: A registry including consecutive HF patients who underwent a first implant of an ICD (891 patients) or a CRT-D device (709 patients) in 2006-2010 was followed (median 1487 days and 1516 days, respectively), collecting administrative data on survival, all-cause hospitalizations, cardiovascular or HF hospitalizations, and days alive and out of hospital (DAOH). Survival free from death/cardiac transplant was 61.9% and 63.8% at 5 years for ICD and CRT-D patients, respectively. Associated comorbidities (Charlson Comorbidity Index) had a significant impact on death/cardiac transplant, as well as on hospitalizations. The median values of DAOH% were 97.4% for ICD and 97.7% for CRT-D patients, but data were highly skewed, with the lower quartile of DAOH% values including values ranging between 0% and 52.8% for ICD and between 0% and 56.1% for CRT-D patients. Charlson Comorbidity Index was a very strong predictor of DAOH%. CONCLUSIONS: Patients who were implanted in 'real world' clinical practice with an ICD or a CRT-D device have, on average, a relatively favourable outcome, with a survival of around 62-64% at 5 years, but with an important burden of hospitalizations. Comorbidities, as evaluated by means of the Charlson Comorbidity Index, have a significant impact on outcomes in terms of mortality/heart transplant, hospitalizations and days spent alive and out of hospital.

CHADS2 and CHA2DS2-VASc scores to predict morbidity and mortality in heart failure patients candidates to cardiac resynchronization therapy.

AIMS: CHADS2 and CHA2DS2-VASc scores are pivotal in assessing the risk of stroke in atrial fibrillation patients, and were recently proved to predict hospitalizations and mortality in specific clinical settings. Aim of this study was to evaluate whether these scores could predict clinical outcomes [first hospitalization for heart failure (HF) and a combined event of HF hospitalization and death for any cause] in patients candidates to cardiac resynchronization therapy and implantable defibrillator (CRT-D). METHODS AND RESULTS: In a retrospective multicentre Italian study, we enrolled 559 consecutive HF patients candidates to CRT-D, and we grouped them in three pre-specified risk classes: low (CHADS2/CHA2DS2-VASc 1-2), moderate (CHADS2/CHA2DS2-VASc 3-4), and high (CHADS2 5-6/CHA2DS2-VASc 5-8). All patients underwent regular follow-up at implanting centres every 6 months; data collection was extended till the 72th month of follow-up. At a median FU of 30 months, 143 patients (25.4%) were hospitalized for HF and 110 (19.5%) died. Event-free survival analysis showed a significant difference according to baseline CHADS2 and CHA2DS2-VASc scores (Log-Rank for HF P < 0.001 for CHADS2 and CHA2DS2-VASc; Log-Rank for combined end-point P = 0.001 for CHADS2, P < 0.001 for CHA2DS2-VASc). At multivariate analysis, independent predictors of endpoints were: previous atrial fibrillation (AF) or AF at implant, NYHA class, QRS duration and the CHA2DS2-VASc score (for HF hospitalization P = 0.013; for the combined event, P = 0.007), while the CHADS2 score was not independently associated with either the end-points. CONCLUSION: In CRT-D patients, pre-implant CHA2DS2-VASc score is an independent predictor of major clinical events at 30-month follow-up.

Electrocardiographic criteria of true left bundle branch block: a simple sign to predict a better clinical and instrumental response to CRT.

BACKGROUND: Cardiac resynchronization therapy (CRT) has proved to be very effective in improving morbidity and mortality in patients affected with severe congestive heart failure. Its efficacy has been shown to be greater in patients with left bundle branch block (LBBB). The aim of our study was to verify if newly proposed criteria for true LBBB identify patients with a better clinical and instrumental response to CRT. METHODS: Between May 2007 and April 2011, 111 patients with left ventricular ejection fraction (LVEF) ≤ 35% and LBBB morphology received a CRT device and were divided into two groups according to QRS morphology. Group 1 (61 patients) consisted of patients with "true" LBBB morphology; group 2 (50 patients) consisted of patients with "false" LBBB. The primary endpoint was the utility of criteria for true LBBB to predict a composite endpoint of all-cause mortality and hospital admission with heart failure. The secondary endpoint was the utility of the same criteria to predict an absolute increase in LVEF ≥ 10%. RESULTS: "False" LBBB morphology and a dose of bisoprolol <5 mg at last follow-up were the only parameters related to clinical outcome in multivariate analysis (respectively: hazard ratio [HR] 3.98, confidence interval [CI] 95% 1.51-10.48; HR 0.15, CI 95% 0.05-0.43). "True" LBBB morphology was the only variable significantly related to a greater increase in LVEF (HR 4.57, CI 95% 1.36-8.28). CONCLUSION: True LBBB morphology is related to a higher event-free survival rate in CRT patients and better echocardiographic response.

Value of right ventricular-left ventricular interlead electrical delay to predict reverse remodelling in cardiac resynchronization therapy: the INTER-V pilot study.

AIMS: Few studies have systematically evaluated the value of intra-procedural parameters in predicting response to cardiac resynchronization therapy (CRT). We investigated whether intracardiac (electrogram) measurements of electrical delays between the positioned right ventricular (RV) and left ventricular (LV) leads at implantation could predict the mid-term CRT response. METHODS AND RESULTS: Fifty-two patients underwent CRT implantation according to standard techniques and clinical indications. The RV-LV interlead electrical delay measured during spontaneous rhythm and the difference between the pacing-induced (Deltap) RV-LV interlead electrical delays measured during RV and LV pacing were defined intraoperatively using the electrical depolarizations registered at the ventricular leads on the device programmer. At 6 months, a reduction of LV end-systolic volume > or = 15% was used to define CRT responders. Responders (62%), when compared with non-responders, showed a higher proportion of ischaemic aetiology (P = 0.007) and a lower value of DeltapRV-LV interlead electrical delay (22.1 +/- 18.4 vs. 46.3 +/- 15.0 ms, P = 0.0001). At multivariate analysis, the DeltapRV-LV interlead electrical delay was the only independent predictor of response to CRT (P = 0.001). For such a parameter, the receiving operating characteristic curve analysis identified a cut-off value of 42 ms corresponding with the highest accuracy: sensitivity 90.6%; specificity 70%; positive and negative predictive value 83% and 82%, respectively. Conversely, no difference was ascertained between responders and non-responders when RV-LV interlead electrical delay was measured during spontaneous rhythm (76.1 +/- 28.5 vs. 89.6 +/- 21.2, P = 0.078). CONCLUSION: Intraprocedural measuring of paced RV-LV interlead electrical delay obtained during RV and LV pacing predicts mid-term CRT response.

Management of traumatic implantable cardioverter defibrillator lead perforation of the right ventricle after car accident: a case report.

The authors reported a case of traumatic implantable cardioverter defibrillator (ICD) lead perforation of the right ventricular (RV) apex caused by a motor vehicle accident. Clinical and echocardiographic features combined with changes in electrical parameters of the offending lead were decisive for the final diagnosis. Optimal management of ICD lead RV wall perforation is currently unclear. In our report, RV perforation was responsible for cardiac tamponade. This complication was uneventfully managed by open surgical procedure.

Value of baseline left lateral wall postsystolic displacement assessed by M-mode to predict reverse remodeling by cardiac resynchronization therapy.

Although left ventricular (LV) dyssynchrony assessed by ultrasound is emerging as superior to QRS duration in predicting response to cardiac resynchronization therapy (CRT), the role of conventional echocardiographic parameters of dyssynchrony is still debated. Forty-eight patients with heart failure in New York Heart Association classes III to IV, LV ejection fraction < or =35%, and QRS duration > or =120 ms were studied. LV dyssynchrony was evaluated by M-mode as septal-to-posterior wall motion delay and left lateral wall postsystolic displacement (LWPSD). Interventricular dyssynchrony was defined as the difference between the LV and right ventricular preejection periods measured by standard Doppler. Reverse remodeling was defined as an LV end-systolic volume decrease > or =15% after 6 months of CRT. Thirty-one patients (65%) were considered responders to CRT. At baseline responders differed from nonresponders by having less severe New York Heart Association class (p = 0.006), lower percentage of ischemic cause (p = 0.006), longer PR interval (p = 0.013), shorter LV diastolic filling time corrected for heart rate (p = 0.005), and presence of LWPSD (p = 0.003). At multivariate analysis, predictors of CRT response were LWPSD (odds ratio [OR] 1.045, 95% confidence interval [CI] 1.001 to 1.091; p = 0.043), LV diastolic filling time corrected for heart rate (OR 0.855, 95% CI 0.744 to 0.981, p = 0.026), and nonischemic cause (OR 0.109, 95% CI 0.018 to 0.657, p = 0.016). In conclusion, preimplantation assessment of cardiac dyssynchrony based on M-mode LWPSD may predict LV reverse remodeling after CRT, especially in patients with nonischemic cause and shorter diastolic filling time. This suggests the potential role of baseline postsystolic mechanical phenomena in determining response to CRT independently of QRS duration.