Meta-analysis of safety and efficacy of uninterrupted warfarin compared to heparin-based bridging therapy during implantation of cardiac rhythm devices.

Optimal management of perioperative anticoagulation in patients undergoing pacemaker or implantable cardioverter-defibrillator implantation is not yet established. We performed a meta-analysis of the published literature to assess the safety and efficacy of perioperative heparin-based bridging therapy versus uninterrupted warfarin therapy in patients undergoing pacemaker or implantable cardioverter-defibrillator implantation. We performed a systematic review of MEDLINE (1950 to 2012), EMBASE (1988 to 2012), Cochrane Controlled Trials Register (fourth quarter 2011), and reports presented at scientific meetings (1994 to 2011). Randomized controlled trials, case-control, or cohort studies comparing the safety and efficacy of uninterrupted warfarin therapy to heparin-based bridging therapy were eligible. Outcomes reported in eligible studies were rates of bleeding and thromboembolic events. Of 3,195 reports initially reviewed, we identified 8 studies enrolling 2,321 patients for the meta-analysis. Maintenance of therapeutic warfarin was associated with significantly lower bleeding postoperatively compared to heparin-based bridging therapy (odds ratio 0.30, 95% confidence interval 0.18 to 0.50, p <0.01). There was no significant difference in risk of thromboembolic events between these 2 strategies (odds ratio 0.65, 95% confidence interval 0.14 to 3.02, p = 0.58). In conclusion, strategy of uninterrupted warfarin therapy throughout pacemaker or implantable cardioverter-defibrillator implantation is associated with decreased risk of bleeding without increasing risk of thromboembolic events. This strategy is a viable alternative to heparin-based bridging therapy.

Devices to treat peripheral chronic total occlusions.

Chronic total occlusions occur in approximately 40% of patients with peripheral vascular disease and are a difficult lesion subset to treat by endovascular approaches. The challenge lies in the difficulty in placing a wire across the site of occlusion and remaining in an intraluminal position. Conventional percutaneous transluminal balloon angioplasty for chronic total occlusions involves advancing a stiff wire through the site of obstruction, has the chance for vessel dissection and perforation, and is associated with high rates of procedural failure. Several mechanical devices have thus been developed to treat peripheral chronic total occlusions. In this article, we provide a review of the currently available devices that may increase the procedural success of treating peripheral chronic total occlusions.

Electromagnetic interference between external defibrillator and cardiac resynchronization therapy-pacemaker (CRT-P) devices.

BACKGROUND: Implantable heart rhythm devices are susceptible to interference in hospitals where electromagnetic interference (EMI) sources are ubiquitous. CASE DESCRIPTION: We report three cases in which EMI from the external defibrillator caused the inability to interrogate Boston Scientific cardiac resynchronization therapy-pacemaker (CRT-P) devices. We have documented interference with the Boston Scientific CRT-P Contact Renewal device model numbers H120/H125 (Natick, MA, USA) and two brands of external defibrillators: the Philips Heartstart XL model number M4735A (Andover, MA, USA) and the Hewlett-Packard Codemaster model number M1722B (Palo Alto, CA, USA). For device implants, we routinely place external pacing pads with the external defibrillator in the "standby" mode for transcutaneous pacing so that only the pacer "start/stop" button needs to be pressed when necessary. We have not been able to interrogate three consecutive Boston Scientific CRT-P devices prior to closure while the external defibrillator had the back-up pacing mode on "standby." In our initial case, a second device was opened because this interaction was not recognized. We documented EMI with the standby pacing mode ON and discovered that by disabling only the "standby" pacing mode on the external defibrillator, the device could be interrogated without difficulty. CONCLUSIONS: This is a case series reporting EMI with a Boston Scientific CRT-P Contact Renewal device H120/H125 telemetry from an external defibrillator with pacing mode on "standby." Failure to recognize this important interaction may lead to inappropriate device and resource utilization.

Use of a percutaneous left ventricular assist device for high-risk cardiac interventions and cardiogenic shock.

OBJECTIVE: We sought to describe the use of the TandemHeart percutaneous left ventricular assist device (PVAD) in a group of high-risk patients undergoing complex cardiovascular procedures. BACKGROUND: There is a substantial risk of acute decompensation and death in patients with cardiogenic shock or a reduced cardiac reserve undergoing high-risk cardiovascular interventions. The TandemHeart PVAD provides near-total hemodynamic support in this setting. METHODS: Thirty-seven high-risk patients underwent placement of the TandemHeart PVAD during 38 separate procedures between April 2007 and April 2009. PVAD insertion was considered emergent if a patient was not expected to survive more than 6 hours without PVAD support. Technical success was defined as successful initiation of the PVAD and completion of the intended interventional procedure. RESULTS: All 37 patients were in cardiogenic shock or undergoing complex coronary and valvular interventions with a high probability of hemodynamic collapse. The mean (+/- standard deviation) patient age was 73 +/- 14 years; 97% were in either NYHA class III-IV heart failure or cardiogenic shock; and the mean EuroSCORE was 11 +/- 3.4. Indications for ventricular assist device placement included critical aortic stenosis (n = 8), severe left main coronary stenosis (n = 18), severe multivessel coronary stenosis (n = 19) and severe cardiomyopathy (n = 23). Four patients were being managed for fulminant myocarditis, ventricular free-wall rupture, flail mitral valve or severe paravalvular leak. Despite their critical status and frequent (82%) need for post-procedure blood transfusion, this complex and high-risk patient population tolerated PVAD-supported intervention well and technical success was achieved in all patients. Seventy-one percent of patients survived to hospital discharge with improved functional status. Most deaths occurred in patients not expected to survive due to their moribund status and multiorgan failure. CONCLUSION: This experience demonstrates the utility and effectiveness of TandemHeart PVAD support in patients with advanced disease, critical clinical status and limited therapeutic options.

Peripheral chronic total occlusions treated with subintimal angioplasty and a true lumen re-entry device.

OBJECTIVE: We sought to verify how effective the Pioneer catheter (Medtronic, Inc., Minneapolis, Minnesota) is in overcoming the complexity of re-entry during subintimal angioplasty and provide a case series describing the technique. BACKGROUND: Subintimal angioplasty is effective in treating peripheral chronic total occlusions (CTO). However, this technique is often limited by the inability to re-enter the true lumen after subintimal crossing of the occluded segment. The Pioneer catheter was the first device to address this difficulty associated with subintimal angioplasty. METHODS: A retrospective review of 21 consecutive cases of peripheral CTOs requiring use of the Pioneer catheter were reviewed. The patients' demographics, indications for the procedure, location and extent of occlusion, lesion characteristics, technique, procedural success and complications were recorded. RESULTS: Twenty of 21 cases were procedurally successful (defined as < or = 30% post-procedure stenosis), for a rate of 95%. The most commonly occluded vessels were the common iliac artery and the superficial femoral artery. The average occlusion length was 107 mm (standard deviation = 87) with a range of 23-300 mm. Both antegrade and retrograde approaches were successful. There was only 1 complication in the study population. CONCLUSIONS: The Pioneer catheter is a re-entry device that is versatile and improves success rates of subintimal angioplasty, which may lead to improvement in the care of patients with CTOs. The cases series demonstrates the use of the Pioneer catheter in treating CTOs.

Use of high-frequency vibrational energy in the treatment of peripheral chronic total occlusions.

PURPOSE: Peripheral chronic total occlusions (CTO) are challenging lesions to treat. The CROSSER system (FlowCardia, Sunnyvale, CA) uses high-frequency low-amplitude vibrations to break through the cap of the CTO and had been shown to be successful in coronary CTOs. This is a case series demonstrating the use of the CROSSER system with peripheral CTOs. CASE REPORTS: Three patients with peripheral CTO of various lengths, locations, and complexities were treated with the CROSSER system. The device allowed placement of a guidewire across the area of occlusion, thus permitting further percutaneous intervention. The CROSSER system was effective with both ostial and distal lesions, tapered and abrupt lesion morphologies, and was used from both an ipsilateral (antegrade access) and contralateral approach. CONCLUSION: The CROSSER system is an additional device that may be used to treat peripheral CTOs.

Complication rate of diagnostic carotid angiography performed by interventional cardiologists.

OBJECTIVE: The aim of this study was to evaluate the complication rate of diagnostic carotid angiography performed by interventional cardiologists and compare it to previously published data. BACKGROUND: Percutaneous treatment for carotid artery stenosis is increasingly being performed. Previously published data describes the complication rate of diagnostic carotid angiography performed by radiologists and vascular surgeons, yet the information regarding interventional cardiologists is sparse. Currently in the United States, interventional cardiologists perform a great deal of diagnostic carotid angiograms. METHODS: A retrospective analysis was done on 333 patients who underwent diagnostic carotid angiography at a single medical center from January 2000 to February 2007. Medical records were reviewed for cardiovascular risk factors, indications for the procedure, angiography technique and in-hospital complications. Complications were categorized as neurological and non-neurological. Neurological complications were further grouped into transient (<7 days) or permanent. Non-neurological complications were grouped into major (requiring additional treatment) or minor. RESULTS: Three hundred and thirty-three patients underwent 347 diagnostic carotid angiograms. Twelve (3.5%) complications occurred in 12 patients. No cerebral vascular accidents occurred and only one (0.3%) transient ischemic attack occurred. Two patients required blood transfusions following the index procedure yielding a major non-neurological complication rate of 0.6%. Review of the literature revealed a transient neurological complication rate from 0 to 2.4% and a major non-neurological complication rate of 0.26-4.3%. CONCLUSIONS: Neurological and non-neurological complication rates for carotid angiograms performed by interventional cardiologists are low and compare well with the literature. Interventional cardiologists can safely perform diagnostic carotid angiography with low complication rates.