Electromagnetic interference from left ventricular assist devices detected in patients with implantable cardioverter-defibrillators.

INTRODUCTION: Electromagnetic interference (EMI) from left ventricular assist devices (LVADs) can cause implantable cardioverter-defibrillator (ICD) oversensing. We sought to assess the frequency of inappropriate shocks/oversensing due to LVAD-related EMI and prospectively compare integrated (IB) versus dedicated bipolar (DB) sensing in patients with LVADs. METHODS: Single-center study in LVAD patients with Medtronic or Abbott ICDs between September 2017 and March 2020. We excluded patients that were pacemaker dependent. Measurements were obtained of IB and DB sensing and noise to calculate a signal-to-noise ratio (SNR). Device checks were reviewed to assess appropriate and inappropriate sensing events. RESULTS: Forty patients (age 52 ± 14 years, 75% men, 38% ischemic cardiomyopathy) were included with the median time between LVAD implantation and enrollment of 6.7 months (2.3, 11.4 months). LVAD subtypes included: HeartWare (n = 22, 55%), Heartmate II (n = 10, 25%), and Heartmate III (n = 8, 20%). Over a follow-up duration of 21.6 ± 12.9 months after LVAD implantation, 5% of patients (n = 2) had oversensing of EMI from the LVAD (both with HeartWare LVADs and Abbott ICDs) at 4 days and 10.8 months after LVAD implantation. Both patients underwent adjustment of ventricular sensing with resolution of oversensing and no further events over 5 and 15 months of further follow-up. The SNR was similar between IB and DB sensing (50 [29-67] and 57 [41-69], p = 0.89). CONCLUSION: ICD oversensing of EMI from LVADs is infrequent and can be managed with reprogramming the sensitivity. There was no significant difference in the R-wave SNR with IB versus DB ICD leads.

Impact of ultra-conservative ICD programming in patients with LVADs: Avoiding potentially unnecessary tachy-therapies.

BACKGROUND: Patients with left ventricular assist devices (LVAD) often tolerate ventricular arrhythmias (VA). We aim to assess the frequency and outcomes of ICD therapies averted by ultraconservative ICD programming (UCP) in LVAD patients. METHODS: This single center, retrospective cohort study included patients with LVADs and ICDs implanted from 2015 to 2019 that had UCP. The aim for UCP was to maximally delay VA treatments and maximize anti-tachycardia pacing (ATP) prior to ICD shocks. VA events were reviewed after UCP and evaluated under prior conservative programming to assess for potentially averted events (that would have resulted in either ATP or defibrillation with prior programming). RESULTS: Fifty patients were included in the study with follow-up of median 16 ± 10.2 months after UCP. The median time from LVAD implantation to reprogramming was 7 days (IQR 5-9 days). Fourteen patients (28%) had potentially averted VA events that would have been treated with their prior ICD programming (82 total events, median two events per patient, IQR 1-10 events). Treated VA events occurred in 15 patients (30%). Eleven of the 14 patients with potentially averted VAs had treated events as well. Only one patient reported definitive symptoms of self-limited "dizziness" during a potentially averted event that did not result in hospitalization. No patients died of complications from or needed emergent care/hospitalization due a potentially averted VA. CONCLUSIONS: UCP in LVAD patients likely prevented unnecessary VA treatments in many patients with minimal reported symptoms during these potentially averted events. Prospective studies are necessary to confirm these findings.

Impact of short term oral steroid use for intravenous contrast media hypersensitivity prophylaxis in diabetic patients undergoing nonemergent coronary angiography or interventions.

OBJECTIVES: Oral steroids are routinely administered in the United States for prophylaxis of iodinated contrast media hypersensitivity (ICMH). We studied the impact of short-term steroid use in diabetic patients with ICMH undergoing nonemergent coronary angiography. METHODS: We retrospectively analyzed records of diabetic patients with and without ICMH who underwent nonemergent coronary angiography at our center. Primary study endpoint was 30-day major adverse cardiac events (MACE) and secondary endpoints were pre- and postprocedure fasting blood glucose (FBG), highest in hospital blood glucose, pre- and postprocedure systolic blood pressure (SBP), and use of intravenous insulin and antihypertensive medications. RESULTS: A total of 88 diabetics with ICMH (study group) and 76 diabetics without ICMH (control group) undergoing angiography were enrolled. Demographics and hemoglobin A1c values were similar in both groups. Preprocedural FBG was significantly higher in the study group. The study group had significantly higher post angiography FBG (239.93 + 96.88 mg/dl vs. 156.6 + 59.88 mg/dl) and greater use of intravenous (IV) insulin (67.27% vs. 32.43%). Further, those who received steroids had significantly higher systolic SBP postprocedure (146.16 + 25.35 mmHg vs. 130.8 + 21.59 mmHg), a higher incidence of severe hypertension and use of IV antihypertensive medications (80.95% vs. 19.05%) periprocedurally. There were no differences in 30-day MACE between groups. CONCLUSION: Short-term steroid use for ICMH results in a significant increase in surrogate markers for adverse clinical events after coronary procedures. Study findings highlight the need for better periprocedural management of these patients and to limit steroid prophylaxis to those with only true ICMH.

Safety and Feasibility of Rotational Atherectomy in Elderly Patients With Severe Aortic Stenosis.

BACKGROUND: Percutaneous coronary intervention (PCI) followed by transcatheter aortic valve replacement (TAVR) is an alternative to surgery in patients with severe aortic stenosis (AS) and coronary artery disease (CAD). In many, the coronary arteries are severely calcified and best treated with rotational atherectomy (RA). However, RA is not routinely performed in severe AS patients due to safety concerns. There is a paucity of data on the safety of RA in severe AS patients with calcific CAD. METHODS: We retrospectively analyzed the medical records of 29 patients with severe AS who underwent elective RA-facilitated PCI at our center between January 1, 2011 and December 31, 2015. RESULTS: Twenty-nine patients (mean age, 79.8 ± 8.8 years) were enrolled. Mean aortic valve area was 0.71 ± 0.20 cm², mean aortic valve gradient was 40.32 ± 9.88 mm Hg. All PCIs were successful (mean diameter stenosis, 86.3 ± 7.6%; mean burr size, 1.62 ± 0.19 mm). Nineteen patients (65.5%) required temporary pacemaker. Eight patients (27.6%) required vasopressors during PCI. There was a significant reduction in systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and heart rate (HR) during RA, but without clinical events. No procedure was aborted and there were no deaths or clinical myocardial infarctions. CONCLUSION: RA-facilitated PCI can be safely performed in elderly patients with severe AS and severely calcified CAD with low risk of complications. There was a significant but transient drop in SBP, DBP, MAP, and HR during RA. However, this was not associated with clinically significant adverse events.