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Browsing by Author "Zipes, Douglas P."
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Item Association of the US Department of Justice Investigation of Implantable Cardioverter-Defibrillators and Devices Not Meeting the Medicare National Coverage Determination, 2007-2015(AMA, 2018-07) Desai, Nihar R.; Bourdillon, Paul M.; Parzynski, Craig S.; Brindis, Ralph G.; Spatz, Erica S.; Masters, Claire; Minges, Karl E.; Peterson, Pamela; Masoudi, Frederick A.; Oetgen, William J.; Buxton, Alfred; Zipes, Douglas P.; Curtis, Jeptha P.; Medicine, School of MedicineImportance The US Department of Justice (DOJ) conducted an investigation into implantable cardioverter-defibrillators (ICDs) not meeting the Centers for Medicare & Medicaid Services National Coverage Determination (NCD) criteria. Objective To examine changes in the proportion of initial primary prevention ICDs that did not meet NCD criteria following the announcement of the DOJ investigation at hospitals that reached settlements (settlement hospitals) and those that did not (nonsettlement hospitals). Design, Setting, and Participants Multicenter, longitudinal, serial cross-sectional analysis of 300 151 initial primary prevention ICDs among Medicare beneficiaries from January 1, 2007, through December 31, 2015, at 1809 US hospitals in the National Cardiovascular Data Registry (NCDR) ICD Registry, of which 452 hospitals (with 99 591 primary prevention ICDs) reached settlements with the DOJ. Exposures The DOJ investigation announcement in 2010. Main Outcomes and Measures Proportion of initial primary prevention ICDs not meeting NCD criteria. Results In January 2007, the proportion of initial ICDs not meeting NCD criteria was 25.8% (95% CI, 24.7% to 26.8%) at settlement hospitals and 22.8% (95% CI, 22.1% to 23.5%) at nonsettlement hospitals (P < .001). Over the study period, there was a 62.7% (95% CI, 59.2% to 66.1%) relative decrease and 16.1% (95% CI, 14.8% to 17.5%) absolute decrease in the proportion of ICDs not meeting NCD criteria at settlement hospitals compared with a 53.2% (95% CI, 50.4% to 56.0%) relative decrease and 12.1% (95% CI, 11.2% to 13.0%) absolute decrease in proportion at nonsettlement hospitals (P < .001 for both; P for interaction < .001). Trends significantly differed between hospital groups only in the period following the announcement of the DOJ investigation (January 2010-June 2011), with larger and more rapid decreases at settlement hospitals (P for interaction = .01). Over the study period, there was a 32.8% (95% CI, 29.9% to 35.7%) relative decrease and a 1703 ICDs (95% CI, 1520 to 1886) absolute decrease in the volume of primary prevention ICDs implanted at settlement hospitals compared with a 17.4% (95% CI, 14.8% to 20.0%) relative decrease and a 1495 ICDs (95% CI, 1249 to 1741) absolute decrease in volume at nonsettlement hospitals (P < .001 for both; P for interaction < .001), with more modest decreases or slight increases in secondary prevention ICD volume. These patterns were similar when examining ICD utilization among non–Medicare beneficiaries. Conclusions and Relevance From 2007 through 2015, the volume of primary prevention implantable cardioverter-defibrillators and the proportion of devices not meeting the Centers for Medicare & Medicaid Services National Coverage Determination criteria decreased at all hospitals with substantially larger decreases at hospitals that reached settlements in the US Department of Justice investigation. These patterns extended to implantable cardioverter-defibrillators placed in non–Medicare beneficiaries, which were not the focus of the US Department of Justice investigation.Item Chronic Low-Level Vagus Nerve Stimulation Reduces Stellate Ganglion Nerve Activity and Paroxysmal Atrial Tachyarrhythmias in Ambulatory Canines(Office of the Vice Chancellor for Research, 2011-04-08) Shen, Mark J.; Shinohara, Tetsuji; Park, Hyung-Wook; Frick, Kyle; Ice, Daniel S.; Choi, Eue-Keun; Han, Seongwook; Sharma, Rahul; Shen, Changyu; Fishbein, Michael C.; Chen, Lan S.; Lopshire, John C.; Zipes, Douglas P.; Lin, Shien-Fong; Chen, Peng-ShengIntroduction: Left sided low-level vagus nerve stimulation (LL-VNS) is used clinically for epilepsy and depression. We hypothesize that LL-VNS can suppress sympathetic outflow and reduce atrial tachyarrhythmias in ambulatory dogs. Methods: We implanted in 12 dogs a neurostimulator in left cervical vagus nerve and a radiotransmitter for continuous recording of left stellate ganglion nerve activities (SGNA), left thoracic vagal nerve activities (VNA) and electrocardiograms. The first 6 dogs (Group 1) underwent 1 week continuous LL-VNS. Another 6 dogs (Group 2) underwent intermittent rapid atrial pacing followed by active or sham LL-VNS on alternate weeks. Results: Integrated SGNA was significantly reduced during LL-VNS (7.8±0.9 mV-s vs. 9.4±0.9 mVs at baseline, P<0.05) in Group 1.The reduction was most apparent from 7 to 9 AM, (31% reduction, 10.8±2.5 mV-s versus 15.6±2.9 mV-s at baseline, P<0.01), along with a significantly reduced heart rate (P<0.05). SGNA-induced heart rate acceleration averaged 107.9±9.0 bpm during LL-VNS and 129.2±9.3 bpm at baseline (P<0.05). LL-VNS did not change VNA. The tyrosine hydroxylase-positive nerve structures in the left stellate ganglion were 99,684±22,257 µm2/mm2 in LL-VNS dogs and 186,561±11,383 µm2/mm2 (P<0.01) in normal control dogs. In Group 2, the frequencies of paroxysmal atrial fibrillation and atrial tachycardia during active LLVNS were 1.4±2.5/d and 8.0±5.8/d, respectively, significantly lower than during sham stimulation (9.2±6.2/d, P<0.01 and 22.0±4.4/d, P<0.001, respectively). Conclusion: LL-VNS suppresses SGNA and reduces the incidences of paroxysmal atrial tachyarrhythmias in ambulatory dogs. Significant neural remodeling of the left stellate ganglion is evident one week after cessation of chronic LL-VNS.Item Determining the Feasibility of Spinal Cord Neuromodulation for the Treatment of Chronic Systolic Heart Failure(Elsevier, 2016-02) Zipes, Douglas P.; Neuzil, Petr; Theres, Heinz; Caraway, David; Mann, Douglas L.; Mannheimer, Clas; Van Buren, Peter; Linde, Cecilia; Linderoth, Bengt; Kueffer, Fred; Sarazin, Scott A.; DeJongste, Michael J. L.; Department of Medicine, IU School of MedicineObjectives The primary objective of the study was a change in left ventricular end-systolic volume index (LVESVi) from baseline to 6 months of spinal cord stimulation (SCS) therapy in the treatment arm compared to the control arm as measured by echocardiography. Secondary objectives were changes in peak oxygen uptake and N-terminal pro–B-type natriuretic peptide (NT-proBNP) between the treatment arm and control arm from baseline through 6 months. Background Abnormal neurohormonal activation is often responsible for progression of heart failure (HF). Treatment has often included drug therapy to modulate the neurohormonal axis. The purpose of the DEFEAT-HF (Determining the Feasibility of Spinal Cord Neuromodulation for the Treatment of Chronic Heart Failure) clinical study was to evaluate whether direct modulation of the nervous system through SCS improved HF metrics, including heart size, biomarkers, functional capacity, and symptoms. Methods The DEFEAT-HF study was a prospective, multicenter randomized (3:2), parallel, single-blind, controlled study to investigate whether SCS was a feasible therapy for the treatment of systolic HF for patients with New York Heart Association functional class III HF, left ventricular ejection fraction (LVEF) ≤35%, QRS duration <120 ms, and left ventricular end-diastolic dimension ≥55 mm. The primary objective of the DEFEAT-HF study was to evaluate the reduction in LVESVi after 6 months of SCS therapy in the treatment arm compared to the control arm. Results In total, 81 patients were enrolled, with 66 successfully randomized and implanted with the SCS device system. Seventy-six percent (50 of 66) had an implantable cardioverter-defibrillator at the baseline visit. Among randomized patients, the mean age was 61 years, 79% were male, mean LVEF was 27%, and mean QRS duration was 105 ms. The change in LVESVi over 6 months was not significantly different between randomization arms (SCS OFF: –2.2 [95% confidence interval: –9.1 to 4.6] vs. SCS ON: 2.1 [95% confidence interval: –2.7 to 6.9]; p = 0.30). Analyses of secondary endpoints for the study were also not significantly different. Conclusions The present study does not provide evidence to support a meaningful change in clinical outcomes for HF patients receiving SCS.Item Interventional and Device-based Autonomic Modulation in Heart Failure(Elsevier, 2015) Shen, Mark J.; Zipes, Douglas P.; Department of Medicine, IU School of MedicineHeart failure is an increasingly prevalent disease with high mortality and public health burden. It is associated with autonomic imbalance characterized by sympathetic hyperactivity and parasympathetic hypoactivity. Evolving novel interventional and device-based therapy has sought to restore autonomic balance by neuromodulation. Results of preclinical animal studies and early clinical trials have demonstrated its safety and efficacy in heart failure. In this review article, we will discuss specific neuromodulatory treatment modalities individually—spinal cord stimulation, vagus nerve stimulation, baroreceptor activation therapy and renal sympathetic nerve denervation.Item Physicians Writing Fiction(Radcliffe Cardiology, 2019-07) Zipes, Douglas P.; Medicine, School of Medicine