First-in-Human Study of the Saranas Early Bird Bleed Monitoring System for the Detection of Endovascular Procedure-Related Bleeding Events.

OBJECTIVES: To evaluate the safety and accuracy of the Early Bird Bleed Monitoring System (EBBMS; Saranas) for the detection of access-site related bleeds in humans undergoing endovascular procedures. BACKGROUND: Bleeding complications after endovascular procedures are frequent and associated with poor prognosis. The EBBMS is a novel technology designed to detect in real time the onset, progression, and severity of internal bleeds. METHODS: The EBBMS was used during and after endovascular procedures, either as a venous or arterial access sheath. The primary endpoint was the level of agreement in bleed detection between the Saranas EBBMS and postprocedural computed tomography. RESULTS: From August 2018 to December 2018, a total of 60 patients from five United States sites were enrolled and underwent elective endovascular procedures (transcatheter aortic valve replacement [67%], percutaneous coronary intervention [13%], percutaneous ventricular assist device [8%], balloon aortic valvuloplasty [7%], transcatheter mitral valve repair/replacement [4%], and endovascular aneurysmal repair [2%]). The EBBMS detected the absence of bleeds in 21 patients (35%) and bleeds in 39 patients (65%), with bleeding severity level 1 in 20 patients (33%), level 2 in 15 patients (25%), and level 3 in 4 patients (7%). Bleeding detection occurred during the procedure in 31% of patients and post procedure in 69% of patients. The level of agreement between the EBBMS and computed tomography scan was high (Cohen's kappa=0.84). No device-related complications were reported. CONCLUSIONS: The EBBMS was safe across a variety of endovascular procedures and detected bleeding events with a high level of agreement with postprocedural computed tomography scan.

Implantable cardioverter-defibrillator prescription in the elderly.

BACKGROUND: Because sudden cardiac death increases with age, implantable cardioverter-defibrillators (ICDs) might greatly benefit the elderly. However, elderly patients are underrepresented in clinical trials, and comorbid conditions may attenuate benefit. OBJECTIVE: The purpose of this study was to examine ICD prescription in the elderly. METHODS: The ages, indications, and implanted ICD type of patients enrolled in the Advancements in ICD Therapy (ACT) Registry were compared to those from the National Cardiovascular Data Registry (NCDR). RESULTS: The ACT Registry included 4,566 patients who underwent first ICD or cardiac resynchronization therapy ICD (CRT-D) implantation. Among these patients, 2.6% were 18-39 years old, 8.6% were 40-49 years, 20.1% were 50-59 years, 27.6% were 60-69 years, 29.0% were 70-79 years, and 12.0% were >or=80 years. In the six age groups, 82.5%, 79.4%, 77.3%, 80.1%, 77.7%, and 74.6% received devices for primary prevention, and single-chamber ICDs were implanted in 41.4%, 42.8%, 38.7%, 33.8%, 25.2%, and 28.1%, respectively (P <.0001). Two-year mortality rates increased incrementally from 5.80% to 17.80% in the six groups (P <.05). Noncardiac death was more common in older than in younger patients. Among patients >or=80 years old receiving a CRT-D, 78% had QRS duration and New York Heart Association class that met accepted implantation criteria. Age distribution, indication, and type of device were similar in the ACT Registry and in 74,476 patients in the NCDR. CONCLUSION: More than 40% of new ICDs and CRT-Ds are implanted in patients >70 years old and more than 10% in patients >or=80 years old. A significant proportion of those receiving a CRT-D did not fulfill accepted criteria for implantation. Noncardiac death occurred more frequently in older patients, but cardiac death rates were similar.

Increased base rate of atrial pacing for prevention of atrial fibrillation after implantation of a dual-chamber pacemaker: insights from the Atrial Overdrive Pacing Study.

AIMS: Different pacing sites and various algorithms have been utilized to prevent atrial fibrillation (AF) in pacemaker recipients. However, the optimal pacing rate settings have not yet been established. In this randomized, prospective, multicentre, single-blinded, cross over study, rate-adaptive pacing at a high base rate (BR) in patients, age 60 years or above, or a history of paroxysmal AF, who underwent dual-chamber (DDD) pacemaker implantation for standard pacing indications, was evaluated for prevention of AF. METHODS AND RESULTS: In the study cohort of 145 patients implanted with DDD pacemakers with a programmable rest rate (RR) feature, the BR/RR settings were sequentially but randomly adjusted as follows: 60 bpm/Off for the baseline quarter (initial 3 months) and then to either 'A-B-C' or 'C-B-A' settings (A = 70/65 bpm, B = 70/Off, C = 80/65 bpm) for the subsequent quarters each of 3 months duration. Data on automatic mode switch episodes, device diagnostics, and a questionnaire evaluating pacemaker awareness and palpitations were collected. Ninety-nine patients, mean age 77 +/- 10 years, who completed the study protocol and followed for 12 months did not show significant differences in the number of mode switch episodes between any settings used. The percentage of atrial pacing was lower during baseline pacing compared to settings A, B, and C (P < 0.0001). Setting C produced a higher percentage of atrial pacing than A and B (P < 0.01). Although a higher percentage of atrial pacing correlated with a lower incidence of mode switch episodes, there was no statistically significant difference in the number of mode switch episodes between settings A, B, and C. There were no significant differences in the questionnaire scores relating to pacemaker awareness or palpitation. CONCLUSION: Overdrive single-site pacing in the right atrium achieved by programming analysed settings in the present study did not reduce AF as assessed by mode switch episodes. Additionally, no change in the symptoms of arrhythmia or awareness of pacing was seen.

AutoCapture with dual-coil leads of implantable cardioverter defibrillator.

AutoCapture (AC) can confirm ventricular capture with true bipolar single coil leads of implantable cardioverter defibrillators (ICD). The compatibility of AC with a new, true bipolar, dual-coil ICD lead needed to be evaluated. This multicenter study enrolled 46 patients (69 +/- 10 years, 37 men) undergoing ICD implantation. All patients received a true bipolar, dual-coil lead. Evoked response (ER) sensitivity and AC threshold tests were performed using a pulse generator with the AC algorithm. Mean capture threshold was 0.85 +/- 0.67 V, pacing impedance 612 +/- 225 Omega, R wave amplitude 13.85 +/- 6.17 mV, and defibrillation threshold 14.4 +/- 5.1 J. AC was recommended in 45 patients (97.8%) with ER and polarization values of 14.86 +/- 7.32 mV and 0.87 +/- 0.69 mV, respectively. The AC algorithm was highly compatible with true bipolar, dual-coil ICD leads. An AC algorithm specifically designed for an ICD may improve the generator longevity. Further examination of AC compatibility with other leads is warranted.

Rhythm classification by correlation-waveform morphology analysis of atrial and ventricular electrogram signals.

We tested the use of correlation-waveform analysis (CWA) of atrial and ventricular electrograms (EGMs) to distinguish ventricular tachycardia (VT) from supraventricular tachycardia (SVT). Patients undergoing electrophysiologic testing were enrolled. EGMs recorded during induced tachycardias were compared with EGMs recorded during sinus and paced rhythms, taken as templates, by assigning a CWA percent-match (CPM) score. Twenty-two patients were studied: 15 men and 7 women (mean age 48 years); 16 with SVT and 6 with VT. Using a sinus-rhythm template, the atrial CPM scores for SVT and VT were 66%+/- 20% and 93%+/- 5%, respectively (P = 0.0034). With a CPM-score cutoff of 85%, the sensitivity for correctly identifying VT was 100% and the specificity for rejection of SVT was 80%. The corresponding ventricular-CPM scores for SVT and VT were 81%+/- 12% and 72%+/- 24%, respectively (P = 0.13, cutoff = 65%, sensitivity = 50%, and specificity = 90%). Using a ventricular template with atrial pacing, the ventricular-CPM scores for SVT and VT were 87%+/- 9% and 76%+/- 14%, respectively (P = 0.028, cutoff = 70%, sensitivity = 50%, and specificity = 93%). Atrial CWA matching is superior to ventricular CWA matching in discriminating between SVT and VT. CWA matching in both chambers could potentially achieve better discrimination.

Effect of short pulse width programming in AutoCapture devices.

Pacing chronaxie can increase over time. The impact of a short pulse duration on threshold (THR) variations, frequency of noncapture episodes, and overall patient safety has not been fully studied. AutoCapture (AC) pacemakers are capable of memorizing THR trends and loss of capture (LOC) episodes. The study included 20 recipients of AC pacemakers (mean age = 76 +/- 9 years, 15 men) followed for 6 months. They were randomly assigned to pulse durations of 0.2 versus 1.0 ms at 1 month, and crossed over to the alternate programming at 3 months. Evoked response (ER) and AC tests were performed at follow-up. At 0.2 ms and 1.0 ms, the mean number of LOC/day was 2.37 +/- 5.81 and 0.91 +/- 0.49, respectively (ns). LOC trends between follow-up were significantly different with 0.2 versus 1.0 ms pulse duration (P < 0.01). AC THR at 1.0 ms was significantly lower (0.44 +/- 0.77) than at 2.0 ms (0.97 +/- 0.26, P < 0.05). No patient reported symptoms related to LOC during the study. Pulse duration programmed near the strength-duration curve is associated with greater variations in THR and LOC. AC responds to these changes by delivering 4.5 V pulses and keeping the capture THR at low, though safe values.

Use of the AutoCapture Pacing System with implantable defibrillator leads.

INTRODUCTION: Previous studies using various bipolar pacemaker leads have shown that the AutoCapture (AC) Pacing System is able to verify ventricular capture and regulate pacing output, increasing patient safety with respect to unexpected threshold changes and potentially prolonging device longevity. An increasing number of patients with implantable cardioverter defibrillators (ICDs) require ventricular pacing that contributes to a shortening of longevity of these systems. This prospective study tested the compatibility of the AC system with bipolar ICD leads. METHODS: The AC algorithm was evaluated prior to ICD testing in 30 ICD recipients. A single coil, active fixation, true bipolar ventricular lead was implanted in 21 patients, and a dual coil, passive fixation, integrated bipolar ventricular lead was implanted in 9 patients. A ventricular evoked response sensitivity test and an AC threshold test were performed using a pacemaker with the ventricular AC algorithm. RESULTS: AC was recommended in 22/30 (73.3%) of implants, including 20/21 (95.2%) with the single coil and 2/9 (22.2%) with the dual coil lead. Mean polarization was lower (1.23 +/- 0.95 mV vs 3.70 +/- 2.33 mV, P = 0.013) while the mean evoked response was higher (18.04 +/- 8.29 mV vs 10.13 +/- 4.22 mV, P = 0.002) with the single coil leads. CONCLUSION: Automatic threshold tracking using the AC is compatible with ICD leads. Leads with lower polarization and greater evoked response are more likely to result in recommendation of AC use. Use of this system offers the potential for increasing ICD generator longevity and improving patient safety in response to late unexpected threshold increases.