Selected Original Research Abstracts from The Journal of Invasive Cardiology March 2011-August 2011

Transcoronary Pacing in a Porcine Model — Impact of Guidewire Insulation

Konstantin M. Heinroth, MD, Susanne Unverzagt, PhD, Michael Buerke, MD, Justin Carter, MD, Dirk Mahnkopf, MD^†, Karl Werdan, MD, Roland Prondzinsky, MD^*
From Martin-Luther-University Halle-Wittenberg, Department of Medicine III, ^†IMTR GmbH Rottmersleben, and ^*Klinikum Merseburg, Department of Medicine I, Merseburg, Germany.
This study was supported by a restricted grant from Biotronik (Berlin, Germany). None of the authors has any financial affiliations with this company. Data analysis and interpretation were performed completely independent from this company.

ABSTRACT: Background. Bradycardia complicating percutaneous coronary intervention (PCI) can require temporary pacing. A transcoronary approach using the guidewire in the coronary artery may be a useful alternative to transvenous pacing. The purpose of the present study was to compare the efficacy of two different coronary guidewires in transcoronary pacing: a novel guidewire (VisionWire^®, Biotronik, Germany) which has a coating to electrically insulate the shaft, thereby maximizing current delivery through the intracoronary section compared to a standard guidewire (without insulation) and a standard guidewire/balloon combination. Methods and Results. Unipolar transcoronary pacing was performed in 15 pigs under general anesthesia. In each animal, the new VisionWire was compared to a standard floppy guidewire and to a standard floppy guidewire loaded with a standard angioplasty balloon (which provides additional shaft insulation). The coronary guidewire was the cathode and a skin patch electrode (on the anterior or posterior chest wall) was the anode. We examined the effect of different electrode combinations on transcoronary pacing as assessed by threshold and impedance data and the magnitude of the epicardial electrocardiogram. Transcoronary pacing with the bare standard guidewire was effective in 77% of cases using an anterior skin patch electrode and in 87% with a posterior patch at pacing thresholds of 6.7 ± 2.9 V and 4.1 ± 3.0 V, respectively. Loading the same guidewire with an angioplasty balloon increased the pacing efficacy to 100% with significantly lower pacing thresholds of 2.4 ± 1.6 V with an anterior patch and 1.6 ± 1.3 V with a posterior patch (p < 0.001). The bare VisionWire yielded 100% pacing efficacy, with the lowest pacing thresholds of 1.6 ± 0.7 V and 1.0 ± 0.6 V anterior and posterior patch positions, respectively (p < 0.001). In all studies the pacing efficacy was higher and thresholds lower with the skin patch electrode on the posterior chest wall than on the anterior chest wall. Conclusions. Transcoronary pacing in the animal model is an effective technique. The VisionWire, (even without the additional insulation of a balloon in place) performed better than a standard guidewire (with or without balloon use), and enabled 100% pacing efficacy at acceptable thresholds. Thus, transcoronary pacing, particularly with specific coronary guidewires may be a useful alternative to transvenous pacing during PCI, particularly in the emergency situation when unexpected bradycardias arise during transradial angioplasty when no central venous access is immediately available for transvenous pacing.

J INVASIVE CARDIOL 2011;23:108–114

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Rotational Atherectomy in the Drug-Eluting Stent Era: A Single-Center Experience

Bryan G. Schwartz, MD^*, Guy S. Mayeda, MD§, Christina Economides, MD^§,
Robert A. Kloner, MD, PhD^*,£, David M. Shavelle, MD^£, Steven Burstein, MD^§
From the ^*Heart Institute and ^§Department of Cardiology, Good Samaritan Hospital, Los Angeles, California and the ^£Department of Internal Medicine, Division of Cardiovascular Medicine, Keck School of Medicine at the University of Southern California, Los Angeles, California.

ABSTRACT: Background. In heavily calcified lesions, rotational atherectomy (RA) improves procedural success and facilitates stent deployment. Reports on RA in the drug-eluting stent (DES) era are limited. The objective of this study was to determine the presenting characteristics, procedural and in-hospital clinical outcomes of patients who underwent RA at our institution in the DES era. Methods. Consecutive cases involving RA between January 1, 2004 and December 31, 2009 at a private, tertiary referral hospital were reviewed retrospectively. Results. A total of 158 patients (236 lesions) who underwent RA are described, including 112 patients (158 lesions) with subsequent DES implantation, 19 patients (28 lesions) with bare-metal stent (BMS) implantation, and 27 patients (50 lesions) with no stent. RA was utilized to modify heavily calcified plaque (84%), as bail-out therapy (16%), to preserve the patency of sidebranches (25%) and as debulking therapy for chronic total occlusion (13 lesions) and in-stent restenosis (7 lesions). DES were not placed in 46 patients (23%) due to reference vessel diameter < 2.25 or > 3.75 mm, inability to deliver DES, or desire to avert clopidogrel therapy. Angiographic and procedural success rates were significantly higher in the DES and BMS groups compared with the no stent group (angiographic success: 99.1% for DES versus 95% for BMS versus 63% for no stent; p < 0.05; procedural success: 96.4% for DES versus 95% for BMS versus 63% for no stent; p < 0.05). Conclusion. In the DES era, RA remains utilized primarily to modify heavily calcified plaque. In unadjusted analysis, procedural success appears high with subsequent stent placement (DES or BMS) versus RA alone. However, 1 in 4 are not candidates for stent placement, and the lower procedural success rate in this population should be considered prior to embarking on RA.

J INVASIVE CARDIOL 2011;23:133–139

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Safety and Efficacy of the New Angio-Seal Evolution^™ Closure Device: A Single-Center Experience

Alessandro Lupi, MD, Maurizio Lazzero, MD, Laura Plebani, MD, Mara Sansa, MD, Angelo S. Bongo, MD
From the Department of Cardiology, Maggiore della Carità, Novara, Italy.

ABSTRACT: Background. The Angio-Seal Evolution (ASE) is a novel vascular closure device (VCD) engineered to reduce the individual skills needed for deployment. A clinical comparison of ASE with manual femoral compression (MC) has never been reported. Methods and Results. A total of 451 consecutive patients treated by ASE following cardiac catheterization were compared with 451 propensity-score matched controls treated by MC. Early failure of ASE and in-hospital major vascular complications (any retroperitoneal hemorrhage, limb-threatening ischemia or surgical repair) and minor vascular complications (any groin hematoma ≥ 5 cm or pseudoaneurysm) following ASE deployment were prospectively assessed. Early failure of ASE was rare (1.8%). In the two groups, the major vascular complication rate was similar [odds ratio (OR), 2.5; 95% confidence interval (CI), 0.5–13.0; p = NS]. However, patients treated by ASE showed a significantly higher risk for minor vascular complications (OR, 2.2; 95% CI, 1.1–4.3; p = 0.029). In comparison to successful deployment, early ASE failure was associated with a very high risk for both major (OR, 15.7; 95% CI, 1.56–158.7; p = 0.002) and minor (OR, 6.1; 95% CI, 1.2–31.8; p = 0.015) vascular complications. Conclusion. In a large, single-center experience, early ASE failure was rare and the rate of major vascular complications following ASE deployment was similar to controls. However, an excess of minor vascular complications (generally large groin hematomas) was observed in patients treated by ASE. Our study confirms that early ASE failure is an important risk factor for severe vascular complications.

J INVASIVE CARDIOL 2011;23:150–155

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Fluoroscopically-Guided Micropuncture Femoral Artery Access for Large-Caliber Sheath Insertion

Mehmet Cilingiroglu, MD, Ted Feldman, MD, Michael H. Salinger, MD, Justin Levisay, MD, Zoltan G. Turi, MD^†
From the NorthShore University HealthSystem, Evanston, Illinois, and ^†Cooper University Hospital, Camden, New Jersey.

ABSTRACT: Over the last decade, significant developments have been made in the treatment of structural heart disease. Some of these techniques require placement of large arterial sheaths for device delivery. Optimal vascular access is essential for successful large-vessel sheath insertion as well as to avoid vascular complications. The critical step for ideal percutaneous vessel entry is single anterior wall-only puncture of the common femoral artery in a location above the femoral bifurcation and below the inguinal ligament. We describe a fluoroscopically-guided micropuncture technique for accurate placement of large-caliber arterial sheaths.

J INVASIVE CARDIOL 2011;23:157–161

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Improvement in Hemodynamics with a New, Larger-Volume (50 cc) Intra-Aortic Balloon for High-Risk Percutaneous Coronary Intervention

Pradeep K. Nair, MD, Sun Scolieri, MD, Ashley B. Lee, MD
From the Cardiovascular Institute at the University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.

ABSTRACT: A primary cause of adverse outcomes among high-risk patients undergoing percutaneous coronary intervention (PCI) may be a diminished capacity to tolerate the hemodynamic and ischemic insults that can occur during the procedure. A common means of mechanical support during PCI has been the intra-aortic balloon pump (IABP). We describe successful periprocedural mechanical support with a new, 50 cc IABP in a patient with both severe left ventricular dysfunction and extensive coronary arteriosclerosis, for whom PCI with stenting was indicated. The prophylactic use of this 50 cc IABP, which traditionally would be contraindicated because of the patient’s height (162.6 cm), markedly increased the diastolic aortic pressure (by ~110 mmHg) over the baseline level, while promptly reducing left-sided heart pressures. This finding appears to exceed the average diastolic augmentation reported for smaller-volume balloons. Although the role of the IABP in high-risk PCI remains controversial, further research is warranted to clarify and compare this new 50 cc IABP to smaller-volume balloons, and ascertain whether the observed hemodynamic benefits can translate into improved clinical outcomes among patients requiring mechanical support during PCI.

J INVASIVE CARDIOL 2011;23:162–166

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Successful Thrombus Aspiration During Primary Percutaneous Coronary Intervention Reduces Infarct Size and Preserves Myocardial Viability: A Cardiac Magnetic Resonance Imaging Study

Yoshimori An, MD, Shuichiro Kaji, MD, Kitae Kim, MD, Atsushi Yamamuro, MD, Makoto Kinoshita, MD^*, Natsuhiko Ehara, MD, Atsushi Kobori, MD, Takeshi Kitai, MD, Tomoko Tani, MD, Toru Kita, MD, Yutaka Furukawa, MD
From the Department of Cardiovascular Medicine, Kobe City Medical Center General Hospital, Kobe, Japan, and the ^*Institute of Biomedical Research and Inno- vation, Kobe, Japan.

ABSTRACT: Background. The purpose of this study was to evaluate the influence of thrombus aspiration during primary percutaneous coronary intervention (PCI) on myocardial viability in patients with ST-segment elevation myocardial infarction (STEMI) using cardiac magnetic resonance imaging (MRI). Methods and Results. We performed cardiac MRI in 62 patients who underwent primary PCI for STEMI with manual thrombus aspiration. We divided the patients into two groups: those who had thrombus aspiration during primary PCI, which resulted in a successful procedure (n = 47 patients; TA group) and those who had thrombus aspiration and an unsuccessful procedure (n = 15 patients; non-TA group). Thrombus aspiration was defined as successful or unsuccessful, based on the histological evidence of atherothrombotic material in the aspirate samples. The infarct volume was quantified using delayed-contrast enhancement on cardiac MRI. The reference volume was defined as transmural myocardial volume at the infarcted segment. Myocardial viability was assessed by a transmurality index defined as the ratio of the infarct volume to the reference volume. Although baseline characteristics and the reference volume were comparable between the two groups (24.5 ± 12.5 ml for TA group versus 29.0 ± 9.6 ml for non-TA group; p = 0.21), the infarct size was significantly smaller in the TA group than in the non-TA group (12.2 ± 7.1 ml versus 17.4 ± 7.1 ml, respectively; p = 0.01). The transmurality index was also significantly lower in the TA group (49.3 ± 10.6% versus 60.9 ± 13.9%, respectively; p = 0.001). Conclusion. Patients with successful TA showed more reduced infarct size and preserved myocardial viability than patients without TA. These effects of TA may lead to preserved left ventricular systolic function and better clinical outcomes.

J INVASIVE CARDIOL 2011;23:172–176

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Causes of Peri-Operative Mortality After Transcatheter Aortic Valve Implantation: A Pooled Analysis of 12 Studies and 1,223 Patients

Raul Moreno, MD¹, Luis Calvo, MD¹, Pablo Salinas, MD¹, David Dobarro, MD¹, Jimenez Valero Santiago, MD, Angel Sanchez-Recalde, MD¹, Guillermo Galeote, MD¹, Luis Riera, MD², Isidro Moreno-Gomez, MD³, Jose Mesa, MD⁴, Ignacio Plaza, MD⁵, Jose Lopez-Sendon, MD¹
From the Departments of ¹Interventional Cardiology, ²Vascular Surgery, ³Cardiovascular Anesthesia, and ⁴Cardiac Surgery, University Hospital La Paz, Madrid, Spain; and ⁵Hospital Infanta Sofia, San Sebastian de los Reyes, Madrid, Spain.

ABSTRACT: Background. In order to improve technique and to prevent serious procedural complications during transcatheter aortic valve implantation (TAVI), it is crucial to identify the causes of death of patients undergoing this procedure. Objective. The objective of this study was to identify the causes of death during the procedure and at 1 month in patients with severe aortic stenosis undergoing TAVI. Methods. 12 published studies with information about the causes of death in patients undergoing TAVI were selected. Overall, 1,223 patients were included in these studies, and 249 deaths were reported (119 at 1 month and 130 at > 1 month post-procedure). Mortality during the procedure and at 1 month was 2.3% and 9.7%, respectively. The proportion of cardiac deaths was higher at < 1 month in comparison with > 1 month (56% versus 34%, respectively; p = 0.001). At 1 month, the most frequent causes of death were cardiac failure/multi-organ failure (24%), sudden death/cardiac arrest (17%), vascular and bleeding complications (17%), stroke (11%), sepsis (11%), and cardiac tamponade (10%). During the procedure, the most frequent causes of death were cardiac tamponade (39%), cardiac failure (21%), cardiac arrest (18%), and vascular and/or bleeding complications (18%). In patients treated with the CoreValve system (Medtronic, Minneapolis, Minnesota) versus those treated with Edwards valves (Cribier-Edwards, Edwards-SAPIEN or SAPIEN XT valve, Edward Lifesciences, Irvine, California), deaths at 1 month due to vascular and bleeding complications were less frequent (3% versus 22%, respectively; p = 0.019), but those due to cardiac tamponade (26% versus 6%, respectively; p = 0.019), and because of aortic regurgitation (10% versus 0%, respectively; p = 0.03) were more frequent. Conclusion. In this pooled analysis, mortality at 1 month after TAVI was 9.7%. The causes of death were widely variable, and of both cardiac and non-cardiac origin. There were some important differences between both devices in the cause of mortality.

J INVASIVE CARDIOL 2011;23:180–184

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Endovascular Treatment of Acute Thoracic Aortic Syndromes with a Proximal Landing Zone Extension Strategy: Procedural and Follow-up Results

Marco Vaghetti, MD^*, Cataldo Palmieri, MD^*, Anees Al-Jabri, MD^*, Marcello Ravani, MD^*, Antonio Rizza, MD^*, Giuseppe Trianni, MD^*, Massimiliano Mariani, MD^*, Mattia Glauber, MD§, Roberto Troiani, MD^£, Dante Chiappino, MD^†, Sergio Berti, MD^*
From the Departments of ^*Cardiology, ^§Cardiac Surgery and ^†Imaging Diagnostic, Pasquinucci Heart Hospital, Toscana Gabriele Monasterio Foundation, Massa, Italy; and the ^£Department of Vascular Surgery, Toscana, Carrara, Italy.

ABSTRACT: Purpose. To report the procedural and long-term follow-up data (mean, 43 ± 29 months; range, 12–90 months) of endovascular stent grafting (ESG) of acute thoracic aortic syndromes (ATAS) with a proximal landing zone extension strategy. Methods. From November 1999 to May 2008, 26 patients (25 males, 1 female; mean age, 57.9 ± 17 years) with ATAS underwent ESG at our institution. Underlying pathologies were: penetrating aortic ulcer (n = 7); rupture of a descending aorta aneurysm (n = 5), post-traumatic false aneurysm (n = 5); acute type B dissection (n = 6) and traumatic descending aorta transection (n = 3). Results. ESG was performed successfully in all patients. In 5 patients (19%), an extra-anatomic revascularization of the supra-aortic vessels was performed. In 19 patients (73%), overstenting of the left subclavian artery, without preliminary revascularization, was performed. The mean proximal landing zone length was 57 ± 19 mm. No intraprocedural deaths occurred; 3 patients died postoperatively (1 from an unrelated cause, 1 from a myocardial infarction and 1 for the sequelae of an ischemic stroke). One patient underwent cardiac surgery for post-procedural retrograde type-A dissection. Follow up involved a computed tomography (CT) scan at 1, 3, 6 and 12 months, then yearly thereafter. At follow up, no deaths or major complications occurred. The CT scans revealed 1 small type-IB endoleak at 1 year. Conclusion. In ATAS patients treated with ESG, the extension of the proximal landing zone, despite the need of subclavian coverage or hybrid procedures, is associated with an immediate procedural outcome and low morbidity at follow-up.

J INVASIVE CARDIOL 2011;23:187–192

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Efficacy and Safety of the Nitinol Clip-Based Vascular Closure Device (Starclose) for Closure of Common Femoral Arterial Cannulation at or Near the Bifurcation: A Propensity Score-Adjusted Analysis

Sripal Bangalore, MD, MHA^*,  Venkatesan D. Vidi, MD^§,  Christopher B. Liu, PAC^§,  Pinak B. Shah, MD^§, Frederic S. Resnic, MD, MS^§
From ^*New York University School of Medicine, New York, New York and ^§Brigham and Women’s Hospital, Boston, Massachusetts.

ABSTRACT: Objectives. To evaluate the efficacy and safety of the nitinol clip-based closure device (Starclose^®, Abbott Vascular, Santa Clara, California) in patients with femoral arterial cannulation at the common femoral artery bifurcation. Background. Femoral artery puncture at the bifurcation of common femoral artery is a relative contraindication for the use of vascular closure devices with intravascular components, and patients with bifurcation cannulation were excluded from the pivotal trials of these devices. The nitinol clip-based closure device (Starclose) is extravascular and is sometimes used in such patients; however, the efficacy and safety of this approach is unknown. Methods. We evaluated consecutive patients undergoing deployment of a Starclose device following a coronary procedure via the femoral artery approach. Quantitative femoral angiographic analyses were performed using a hand caliper. The distance of the artery puncture site from the bifurcation was recorded in each patient. Any arterial cannulation ≤ 3 mm from the bifurcation was categorized as a bifurcation cannulation (as the outer diameter of the nitinol clip of Starclose is 4 mm). Results. Among 1,096 patients who underwent deployment of a Starclose device, 217 (20%) were within 3 mm of the bifurcation. Starclose deployment at the bifurcation was not associated with a significant increase in the risk of any (0.9% vs. 1.0%; p = 0.892) major (0.0% vs. 0.3%; p = 0.389) or minor vascular complications (0.9% vs. 0.7%; p = 0.711) compared to deployment for non-bifurcation cannulations (both for diagnostic and percutaneous coronary interventional procedures). The results were unchanged in both a regression model adjusted for a propensity score (41 baseline covariates) as well as a propensity score-matched cohort (217 bifurcation cannulations vs. 217 non-bifurcation cannulations). Conclusion. In a select group of patients, vascular closure using a extravascular closure device (Starclose) appears to be safe for arterial cannulations at or near the bifurcation.

J INVASIVE CARDIOL 2011;23:194–199

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In Vivo Virtual Histology Intravascular Ultrasound Comparison of Neointimal Hyperplasia Within Drug-Eluting- Versus Bare Metal Stents

Kohei Wakabayashi, MD, Gary Mintz, MD^†, Cedric Delhaye, MD, Yu Jeong Choi, MD, Joon Hyung Doh, MD, Itsik Ben-Dor, MD, Michael Gaglia, Jr., MD, Rajbabu Pakala, MD,  William Suddath, MD, Lowell Satler, MD, Kenneth Kent, MD, Augusto Pichard, MD, Neil Weissman, MD, Ron Waksman, MD
From the Washington Hospital Center, Division of Cardiology, Washington, DC and the ^†Cardiovascular Research Foundation, New York, New York.

ABSTRACT: Background. The process of in-stent neointimal hyperplasia (NIH) between drug-eluting stents (DES) and bare metal stents (BMS) might be different. We compared in vivo composition of in-stent NIH between DES and BMS using virtual histology-intravascular ultrasound (VH-IVUS). Methods and Results. Volumetric VH-IVUS was used to compare in-stent NIH between 23 DES and 15 BMS in 30 patients who underwent coronary angiography because of angina. The inner and outer VH-IVUS contours were drawn in a way to avoid the stent strut artifacts. Cross-sectional analysis was done at every VH-IVUS frame within the stent, thereby allowing volumetric measurement of stent, lumen, and NIH and its components. Baseline characteristics and IVUS measurements were similar between DES and BMS groups. The duration of follow-up was similar between DES (median 38 months [interquartile range, 7–59]) vs. BMS (median 40 months [interquartile range, 7–99]), (p=0.26). % necrotic core (NC) volume was significantly higher in DES than BMS: 19.5 [16.3, 25.6] vs. 12.1 [8.2, 18.5] (p=0.006). %NC volume significantly increased with time in BMS (p=0.007), but not in DES (p=0.24) so that at any given time point, %NC in DES was greater than in BMS. After adjustment for baseline differences, only DES (p=0.003) and stent age (p=0.043) were independent predictors of %NC volume. VH-IVUS in-stent thin-cap fibroatheromas were detected only in the DES group: 34.8% vs. 0%, p=0.013. Conclusion. In vivo composition of in-stent NIH between DES and BMS was different, suggesting that the process of in-stent NIH in DES and BMS is diverse.

J INVASIVE CARDIOL 2011;23:262–268

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Comparison of Six-Year Clinical Outcome of Sirolimus- and Paclitaxel-Eluting Stents to Bare-Metal Stents in Patients with ST-Segment Elevation Myocardial Infarction: An Analysis of the RESEARCH and T-SEARCH Registries

Cihan Simsek, MD, Michael Magro, MD, Eric Boersma, PhD, Yoshinobu Onuma, MD, Sjoerd Nauta, MSc, Joost Daemen, MD, PhD, Marcia Gaspersz, MSc, Robert-Jan van Geuns, MD, PhD, Willem van der Giessen, MD, PhD, Ron van Domburg, PhD, Patrick Serruys, MD, PhD
From the Thoraxcenter, Department of Cardiology, Erasmus Medical Center Rotterdam, the Netherlands.

ABSTRACT: Background. Short- and long-term data showed that drug-eluting stents (DES) significantly decreased target vessel revascularization (TVR) and major adverse cardiac event (MACE) rates compared to bare-metal stents (BMS). However, conflicting long-term data remain for patients with ST-segment elevation myocardial infarction (STEMI). Objective. Our aim was to assess the 6-year clinical outcome of all patients undergoing primary percutaneous coronary intervention (PPCI) for a de novo lesion with exclusive use of BMS, sirolimus-eluting stents (SES) and paclitaxel-eluting stents (PES). Methods. Three PPCI cohorts (BMS = 80; SES = 92; PES = 162) were systematically followed for the occurrence of MACE. Results. Very late stent thrombosis was more common after the implantation of SES as compared to PES or BMS (7.6%, 0.6%, and 0.0%, respectively; p = 0.001). Kaplan-Meier estimates indicate no statistically significant difference for mortality between the three stent types at 6 years (BMS = 25%; SES = 15%; PES = 21%; Log-rank p = 0.2). After adjustment for differences in baseline characteristics, mortality, mortality/myocardial infarction (MI), and MACE rates were significantly lower for SES compared to BMS, but not for PES (aHR = 0.41, 95% CI: 0.17–0.98; aHR = 0.44, 95% CI: 0.21–0.96; aHR = 0.35, 95% CI: 0.17–0.72, respectively). No differences were observed between the three stent types for TVR rates. Conclusion. Neither SES nor PES improved safety or efficacy as compared to BMS in a STEMI population at 6 years. After adjusting, the usage of SES resulted in a significant decrease in mortality, mortality/MI and MACE rates as compared to BMS, in contrast to the usage of PES. SES and PES have a similar effectiveness and safety profile, although very late stent thrombosis was more common with SES.

J INVASIVE CARDIOL 2011;23:336–341