- Email: [email protected]
Canadian Cardiovascular Society (CCS) CCS410 Poster: Outcomes and Registries in CVD Monday, October 25, 2010
Abstracts and mortality. The objective of this study was to investigate the degree of LV mass regression and the changes of LV diastolic function 1 year after transcatheter aortic valve implantation (TAVI). CONCLUSION: A significant regression in LV mass was found 1 year after TAVI. However, regression was incomplete and was not accompanied by an improvement in LV diastolic function.
400
A 3D FSI MODEL OF THE AORTIC VALVE INCLUDING THE CORONARY STRUCTURE – IMPACT OF OSTIA POSITION ON CORONARY FLOW S Nobari, R Mongrain, R Leask, R Cartier Montréal, Québec Several numerical studies have been carried out to improve the quality of the surgical procedures that exist to correct pathologies of the aortic valve. However, none of these studies consider the coronary structures. Incorporating these arteries allow examination of coronary flow perturbations due to mechanical and geometric modifications of this region. In this work, we study the impact of positioning the ostia at different heights during surgical procedures. We believe this positioning can be critical and might affect the amount of blood entering these structures and consequently interfere with the normal sinus vortex creation and subsequently affect valve dynamics. In this study we have, for the first time, created a 3D model of the aortic root including the coronary arteries to study the hemodynamic of this region and the effect of ostia position during surgical procedures such as Bental and remodelling. The results have been derived for the normal height of the ostia and they correspond well with the physiological data available through previous studies and clinical data. Such a model has the potential to aid in improving surgical procedures and a better comprehension of hemodynamic of the region. FQRNT (Le Fonds québécois de la recherche sur la nature et les technologies)
within the Canadian Anticoagulant PCI Registry conducted in eight centres across six provinces in Canada. In this population of patients undergoing PCI across Canada, radial artery access was not associated with increased risk of periprocedural complications. There was no difference in hematological decrease in hemoglobin, clinically documented bleeding or hematoma. Radial arterial access was associated with increased frequency of anticoagulant switching from enoxaparin to unfractionated heparin. Randomized clinical trials comparing arterial access site are critical to determine risks and benefits of the various arterial access procedures. sanofi aventis
403
DISCONTINUATION OF ANTI-PLATELET THERAPIES BUT NOT ANEMIA SEVERITY PREDICTS OUTCOME IN PATIENTS REQUIRING TRANSFUSION FOLLOWING PERCUTANEOUS CORONARY INTERVENTION (PCI) SD Robinson, C Janssen, EB Fretz, B Berry, RG Carere, A Fung, G Simkus, JD Hilton, WP Klinke Victoria, British Columbia BACKGROUND: Bleeding and transfusion following percutaneous coronary intervention (PCI) predicts an increased risk of death although the reason for this is unclear. We investigated whether discontinuation of antiplatelet pharmacotherapy or anemia severity was associated with mortality in patients transfused following PCI. CONCLUSION: The severity of anemia does not appear to predict 30-day mortality in patients requiring transfusion following PCI. Premature discontinuation of anti-platelet agents occurred more frequently in transfused patients who died following PCI. Given their proven benefit in the prevention of recurrent ischemic events and stent thrombosis, early cessation of these medications may contribute to the increased risk of death in patients receiving blood. Victoria Foundation (Canadian Charity 130650898RR0001)
401
POPULATION CHARACTERISTICS AND FINAL DISPOSITION FOR PATIENTS REFERRED TO A FOCUSED TRANSCATHETER AORTIC VALVE IMPLANTATION CLINIC GS Parmar, RJ Chisholm, MD Peterson, DA Latter, AN Cheema Toronto, Ontario Transcatheter Aortic Valve Implantation (TAVI) offers a novel approach for treatment of severe symptomatic aortic stenosis in patients deemed at prohibitive risk for conventional AVR. However, appropriate assessment of risk and benefits at an individual level and careful patient selection is essential to maximize benefits of this emerging technology. In this study, we report population characteristics and follow up outcomes of patients referred to a focused TAVI clinic at a tertiary care hospital for consideration of TAVI. Only 27% of patients referred to a focused TAVI clinic for surgical consideration underwent TAVI. In addition, 14% of patients declined to undergo TAVI and 11% of patients died during the work up process. These findings highlight the importance of careful screening to maximize resource utilization at TAVI clinics. Furthermore, adequate resources to optimize assessment of potential candidates may improve clinical outcomes during the waiting period.
402
Canadian Cardiovascular Society (CCS) CCS410 Poster OUTCOMES AND REGISTRIES IN CVD Monday, October 25, 2010 406
WEIGHT GAIN IS NOT ALWAYS DETRIMENTAL TO HEART RATE VARIABILITY IN PATIENTS WITH DIABETES AFTER CORONARY ARTERY BYPASS SURGERY V Valiquette-Trépanier, G Salamin, P Brassard, J Després, OF Bertrand, N Alméras, O Costerousse, P Poirier Québec, Québec BACKGROUND: Rosiglitazone, an oral anti-diabetic drug, is associated with weight gain while obesity is associated with altered heart rate variability (HRV). However, it is unknown whether or not weight gain resulting from rosiglitazone therapy is associated with changes in HRV. CONCLUSION: Our results suggest that heart rate variability in patients with diabetes after coronary artery bypass surgery is not altered by rosiglitazone therapy despite a significant increase in body weight which is entirely explained by an increase in subcutaneous adiposity.
ARTERIAL ACCESS SITE WITHIN THE CANADIAN ANTICOAGULANT PERCUTANEOUS CORONARY INTERVENTION REGISTRY (CAPCIR)
407
R Welsh, AJ DellaSiega, J Déry, N Fam, E Schampaert, RH Zimmermann, A Fung, M Hervas-Malo, B Rose Edmonton, Alberta Prior registry data and retrospective analysis from clinical trials had suggested a benefit of radial arterial access compared to femoral arterial access in patients undergoing percutaneous coronary intervention (PCI). Despite this, there are limited rigorous data addressing this in a prospective fashion within patients in Canada. Accordingly we assessed arterial access site
F Bonenfant, DH Do, S Lepage, B Essadiqi, M Brochu, P Farand Sherbrooke, Québec Exercise echocardiography (EE) is an accurate non-invasive test to detect inducible ischemia in patients with coronary artery disease (CAD). Previous studies have already shown its good prognostic value. Our center has recently integrated the EE in its clinical exams for CAD investigation.
Can J Cardiol Vol 26 Suppl D October 2010
RAPID LEARNING CURVE WITH GOOD CLINICAL RESULTS OF A NEW EXERCISE ECHOCARDIOGRAPHY PROGRAM
87D
Abstracts Consequently, the number of EE has considerably increased in the last few years. Our objective was to assess the one year prognostic value of EE at our institution. At our center, EE has an excellent negative predictive value. False negatives, although rare, are more common in patients with a history of past revascularisation reflecting the higher pretest probability. Special attention should be given to this group of patients. EE is an accurate exam for CAD prognostic evaluation and requires fewer investments than other second line non invasive stratification exams. This study shows the rapid learning curve of an EE program with good clinical results. These results could be rapidly achieved in other centers especially in a time of scarce resources and restricted supply of medical isotopes.
408
OUTCOME OF PATIENTS SUBJECTED TO MILD THERAPEUTIC HYPOTHERMIA AFTER SUCCESSFUL RESUSCITATION FROM CARDIAC ARREST M Bachand, M Houle, C St-Pierre, P Farand Sherbrooke, Québec BACKGROUND: Despite significant advances in the treatment of heart disease, the outcome of patients experiencing sudden cardiac arrest (SCA) remains poor. Among survivors of SCA, only 20% have a favourable neurologic outcome at hospital discharge. Several studies have shown that mild therapeutic hypothermia markedly mitigates brain damage after SCA. A cooling protocol (involving infusion of refrigerated fluids) for inducing mild hypothermia in survivors of SCA has been implemented in 2006 at our center (CHUS). The goal of our study was to document the outcome of these patients. CONCLUSION: Despite the fact that current guidelines encourage the use of TH for all patients successfully resuscitated, it remains a recommendation based on weaker evidences for patients with factors known to be associated with a poor outcome. Our results question the use of TH for these patients and we believe that the use of cooling protocol at our center should be restrained to the patients presenting with a ventricular tachyarrhythmia as the initial rhythm. Moreover, the large number of patients transferred from other hospitals in our study underscores the importance of starting the cooling at the referent center whenever possible. Finally, our complication rates appear to be similar to those mentioned in the literature, except that we had more cases of pulmonary congestion.
409
SUCCESSFUL INDUCED HYPOTHERMIA POST-CARDIAC ARREST: EVALUATING PROTOCOL TO EXPAND THERAPEUTIC SCOPE M Chan, C Hoffman, W Hui, DJ Kutsogiannis, P Topipat, R Williams Edmonton, Alberta BACKGROUND: Induced hypothermia (IH) improves outcomes, using stringent selection criteria, thus the American Heart Association recommends IH for out-of-hospital cardiac arrest when VF is the initial cardiac rhythm. Systematic reviews demonstrating positive outcomes only included studies where cooling was initiated within 6 hours of arrest. Therefore, investigations need to establish defined protocol for IH to expand its scope. Primarily, we evaluated our IH protocol in terms of survival and neurological outcome, comparing IH patients to matched (by GCS) controls. Our secondary objective was to gain insights about benefits of IH in relation to described selection criteria and protocols. CONCLUSION: IH provided survival benefit when considering patients of similar neurological status on admission. IH may benefit patients who do not meet currently recommended selection criteria. IH patients arresting in-hospital died (27.3%) less often than those arresting out-of-hospital (66.6%) and those without IH (76.2% in controls with GCS under 7). IH patients with initial rhythms other than VF also seemed to derive benefit (65.2% vs 76.2% death in controls with GCS under 7), while those with non-witnessed arrests had similar survival (76.9% deaths) to the controls with similar GCS. In IH protocols, there should also be consideration of the timing of IH initiation, with 6 hours perhaps being a critical threshold. More studies with long-term follow up are required to better understand the neurological outcomes.
88D
411
SAFETY OF AN ACCELERATED TRANSOESOPHAGEAL STRESS ECHOCARDIOGRAPHY IN THE PREOPERATIVE EVALUATION OF HIGH RISK SEVERELY OBESE SUBJECTS AWAITING BARIATRIC SURGERY S Legault, M Sénéchal, S Bergeron, M Tessier, M Arsenault, J Guimond, P Poirier Québec, Québec Severe obesity is associated with an increased risk of coronary artery disease (CAD). Bariatric surgery is an effective procedure for long term weight management as well as reduction of comorbidities. Preoperative evaluation of cardiac operative risk may often be necessary but unfortunately standard imaging techniques are often suboptimal in these subjects. The purpose of this study was to demonstrate the feasibility and safety of transoesophageal dobutamine stress echocardiography (TE-DSE) using an adapted accelerated dobutamine infusion protocol in severely obese subjects with comorbidities being evaluated for bariatric surgery for assessing the presence of myocardial ischemia. In conclusion, TE-DSE with an accelerated protocol is a safe and well tolerated imaging technique for the evaluation of suspected myocardial ischemia and cardiac operative risk in severely obese patients awaiting bariatric surgery.
412
PERCUTANEOUS TRANSLUMINAL SEPTAL MYOCARDIAL ABLATION IN HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY – ACUTE AND MEDIUM-TERM FOLLOW-UP T Hamid, M Luckie, HM Hadi, R Khattar Manchester, United Kingdom BACKGROUND: Percutaneous trans-luminal septal myocardial ablation (PTSMA) is an alternative therapeutic method to the gold standard surgical myectomy in the treatment of left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic obstructive cardiomyopathy (HOCM). PTSMA is performed by injecting alcohol into a target septal branch of the left anterior descending (LAD) coronary artery. Here, we report the acute and medium-term clinical outcomes of patients undergoing PTSMA for symptomatic HOCM in a single tertiary centre in the United Kingdom (UK). CONCLUSION: PTSMA is an effective non-surgical technique for treatment of symptoms related to LVOT obstruction in HOCM. Medium-term follow-up demonstrates persistent reduction in LVOT obstruction and improvement in NYHA functional class. Conduction defects requiring permanent pacemaker implantation may occur. Long-term studies of larger populations are necessary in order to determine the prognostic significance of the procedure.
413
THE CARDIOVASCULAR DISEASE BURDEN IN A COHORT OF METIS PERSONS, COMPARED TO THE REST OF THE POPULATION OF ONTARIO CL Atzema, J Klein-Geltink, M Gravelle, E Asllani, L Pigeau, J MacQuarrie Toronto, Ontario BACKGROUND: The burden of cardiovascular disease in the Métis is unknown. We examined the rates of four major cardiovascular diseases in the Métis, including acute coronary syndromes (ACS), congestive heart failure (CHF), cerebrovascular disease (CVD), and atrial fibrillation, relative to the rest of the Ontario population, as well as associated outcomes. CONCLUSION: The burden of cardiovascular disease was significantly higher in the Métis persons in this cohort, including much higher rates of ACS and atrial fibrillation in particular. In Métis with CHF, hospital readmission rate was double that the rest of the population, but no differences were found for the other diseases. Higher mortality rates were found only in patients with atrial fibrillation. Public Health Agency of Canada (PHAC)
Can J Cardiol Vol 26 Suppl D October 2010
Abstracts
414
MANAGEMENT OF RISK FACTORS AMONG AMBULATORY PATIENTS AT HIGH CARDIOVASCULAR RISK IN CANADA: CAN WE DO BETTER? E Elbarasi, SG Goodman, RT Yan, A Casanova, M Tan, DG Hackam, LA Leiter, A Langer, AT Yan Toronto, Ontario BACKGROUND: Risk factor modification is an important aspect of the management of cardiovascular disease, and is supported by clinical trials and recommended by practice guidelines. Several cross-sectional studies have evaluated the extent to which guideline-recommended treatment targets are attained in ambulatory patients with cardiovascular disease. However, there are limited longitudinal data on the temporal changes in the attainment of these targets among ambulatory patients with cardiovascular disease in Canada. CONCLUSION: A substantial proportion of patients without 6-month follow-up did not attain guideline-recommended BP and LDL-C targets at baseline. Although there were improvements in blood pressure and lipid control at 6 months among patients with follow-up, the majority still failed to achieve both optimal blood pressure and lipid targets. Effective ongoing quality improvement measures for management of cardiovascular risk factors are warranted.
415
A CATCH ALBERTA INTER-PROFESSIONAL INDO-ASIAN CARDIOVASCULAR HEALTH AND MANAGEMENT PROGRAM M Coleman, K Barnachea, J Hefferton, J Koppel, W Mainville, A Wilson, H Yau, B Hatoum, S Wiens, C Cox, M Gukert, N Hassam, CA Jones Calgary, Alberta BACKGROUND: Indo-Asians (IA) are predisposed to hypertension, dyslipidemia, diabetes, obesity, and cardiovascular disease (CVD). A recent study of CVD risk factors in a Calgary, Alberta IA population, identified poor risk factor control and follow-through with treatment recommendations, despite the high level of satisfaction with the program. The purpose of this study is to consult this same IA community to identify the determinants of the poor risk factor control and follow-up. And, based on these findings, pilot the implementation of a CVD prevention program that includes risk factor screening and education sessions targeted to the identified needs of the community members. CONCLUSION: Many IA clients are aware of their CVD risk. For many, management of risk factors is still poor. Client interest in lifestyle education is high; therefore, such education shows promise in improving CVD risk factor management. Further CVD risk screening/education sessions are required in multiple community settings in order to make a greater impact on CVD prevention in the IA population.
Canadian Cardiovascular Society (CCS) CCS415 Poster MANAGEMENT OF BRADY AND TACHYARRHYTHMIAS Monday, October 25, 2010 418
CIRCUMFERENTIAL VS SEGMENTAL ANTRAL ABLATION FOR PAROXYSMAL ATRIAL FIBRILLATION RW Sy, LJ Gula, P Leong-Sit, R Yee, A Krahn, GJ Klein, AC Skanes London, Ontario BACKGROUND: Circumferential antral ablation is widely used for treating paroxysmal AF. However, complete encirclement of the pulmonary vein (PV) antra may not be necessary. We compared a segmental approach limiting ablation to segments of the antra required for PV-LA conduction to a standard circumferential approach.
Can J Cardiol Vol 26 Suppl D October 2010
CONCLUSION: Compared to circumferential ablation, segmental antral ablation achieves similar success rates with shorter procedural and ablation times. A prospective randomized trial is warranted.
419
ELECTROPHYSIOLOGIC CHARACTERISTICS AND ABLATION OF ATRIAL TACHYCARDIA AFTER CIRCUMFERENTIAL ABLATION FOR ATRIAL FIBRILLATION: IMPLICATIONS REGARDING ITS MECHANISMS JP Man, MW Deyell, V Bhole, S Chakrabarti, JA Yeung-Lai-Wah Vancouver, British Columbia BACKGROUND: Atrial tachycardia (AT) is a significant sequel of circumferential ablation (CA) for atrial fibrillation (AF). There are limited data regarding activation mapping and ablation of AT. The aim of this review is to determine whether AT results from deficiencies in the line lesions or occur de novo, using activation mapping techniques. Better characterization of recurrent AT would assist in initial ablation. CONCLUSION: ATs post-CA occur de novo remote from the line lesions in CA in a slim majority of cases; however, recovery of previously created line lesions also contributes to a significant minority of ATs. Concomitant RA isthmus ablation would reduce AT as there is a significant proportion of patients with right sided isthmus-dependent flutters. Correct mapping is crucial in determining the mechanism of AT because of the large variability in causes.
420
ARE TRADITIONAL SVT ENTRAINMENT CRITERIA VALID TO DIFFERENTIATE ATYPICAL AVNRT WITH LONG RETROGRADE CONDUCTION TIME FROM AVRT USING A SLOWLY CONDUCTING SEPTAL ACCESSORY PATHWAY? MT Bennett, P Leong-Sit, LJ Gula, AC Skanes, A Krahn, GJ Klein London, Ontario RV entrainment criteria have been published to distinguish atypical AV node reentrant tachycardia (AVNRT) from atrio-ventricular reentrant tachycardia (AVRT) using a septal accessory pathway. In atypical AVNRT, the difference between the post pacing interval and the tachycardia cycle length (PPI-TCL) is greater than 115 msec. Similarly, the difference in the ventriculo-atrial interval during pacing and tachycardia (StimA-VA) is greater than 85 msec in atypical AVNRT but less in AVRT. These criteria have not been adequately validated in patients with slowly conducting and decremental retrograde pathways. These preliminary data suggest that the traditional ventricular entrainment criteria for SVT mechanism will not be reliable for differentiating atypical AVNRT with a long VA conduction time from AVRT using a slowly conducting or decremental retrograde septal accessory pathway.
421
ABLATION CATHETER IMPEDANCE DECREASES IN THE PULMONARY VEIN AND LEFT ATRIUM DURING AN ATRIAL FIBRILLATION ABLATION PROCEDURE NA Cromie, O Sultan, S Agarwal, R Ayou, L Chen, P Novak, LD Sterns, R Leather, AS Tang Victoria, British Columbia BACKGROUND: Pulmonary vein (PV) isolation is a commonly performed curative procedure for atrial fibrillation. PV stenosis is a complication that occurs in 1% of patients. There is a higher risk of stenosis when ablation is performed within the vein, rather than its antrum. Impedance changes occur between the left atrium (LA) and PV and are frequently used to direct application of radiofrequency ablation. If these impedances changed over time it could lead to inadvertent ablation within the PV increasing the risk of stenosis. This study was designed to monitor impedance changes in the PV and LA during PV isolation. CONCLUSION: During PV isolation, there is a significant drop in impedance within the PVs, the PV os and the LA body. The average impedance for the combined PVmid and PVdist fell from baseline (264Ω) to 248Ω after the first ipsilateral vein isolation and further after all PVs
89D
400
A 3D FSI MODEL OF THE AORTIC VALVE INCLUDING THE CORONARY STRUCTURE – IMPACT OF OSTIA POSITION ON CORONARY FLOW S Nobari, R Mongrain, R Leask, R Cartier Montréal, Québec Several numerical studies have been carried out to improve the quality of the surgical procedures that exist to correct pathologies of the aortic valve. However, none of these studies consider the coronary structures. Incorporating these arteries allow examination of coronary flow perturbations due to mechanical and geometric modifications of this region. In this work, we study the impact of positioning the ostia at different heights during surgical procedures. We believe this positioning can be critical and might affect the amount of blood entering these structures and consequently interfere with the normal sinus vortex creation and subsequently affect valve dynamics. In this study we have, for the first time, created a 3D model of the aortic root including the coronary arteries to study the hemodynamic of this region and the effect of ostia position during surgical procedures such as Bental and remodelling. The results have been derived for the normal height of the ostia and they correspond well with the physiological data available through previous studies and clinical data. Such a model has the potential to aid in improving surgical procedures and a better comprehension of hemodynamic of the region. FQRNT (Le Fonds québécois de la recherche sur la nature et les technologies)
within the Canadian Anticoagulant PCI Registry conducted in eight centres across six provinces in Canada. In this population of patients undergoing PCI across Canada, radial artery access was not associated with increased risk of periprocedural complications. There was no difference in hematological decrease in hemoglobin, clinically documented bleeding or hematoma. Radial arterial access was associated with increased frequency of anticoagulant switching from enoxaparin to unfractionated heparin. Randomized clinical trials comparing arterial access site are critical to determine risks and benefits of the various arterial access procedures. sanofi aventis
403
DISCONTINUATION OF ANTI-PLATELET THERAPIES BUT NOT ANEMIA SEVERITY PREDICTS OUTCOME IN PATIENTS REQUIRING TRANSFUSION FOLLOWING PERCUTANEOUS CORONARY INTERVENTION (PCI) SD Robinson, C Janssen, EB Fretz, B Berry, RG Carere, A Fung, G Simkus, JD Hilton, WP Klinke Victoria, British Columbia BACKGROUND: Bleeding and transfusion following percutaneous coronary intervention (PCI) predicts an increased risk of death although the reason for this is unclear. We investigated whether discontinuation of antiplatelet pharmacotherapy or anemia severity was associated with mortality in patients transfused following PCI. CONCLUSION: The severity of anemia does not appear to predict 30-day mortality in patients requiring transfusion following PCI. Premature discontinuation of anti-platelet agents occurred more frequently in transfused patients who died following PCI. Given their proven benefit in the prevention of recurrent ischemic events and stent thrombosis, early cessation of these medications may contribute to the increased risk of death in patients receiving blood. Victoria Foundation (Canadian Charity 130650898RR0001)
401
POPULATION CHARACTERISTICS AND FINAL DISPOSITION FOR PATIENTS REFERRED TO A FOCUSED TRANSCATHETER AORTIC VALVE IMPLANTATION CLINIC GS Parmar, RJ Chisholm, MD Peterson, DA Latter, AN Cheema Toronto, Ontario Transcatheter Aortic Valve Implantation (TAVI) offers a novel approach for treatment of severe symptomatic aortic stenosis in patients deemed at prohibitive risk for conventional AVR. However, appropriate assessment of risk and benefits at an individual level and careful patient selection is essential to maximize benefits of this emerging technology. In this study, we report population characteristics and follow up outcomes of patients referred to a focused TAVI clinic at a tertiary care hospital for consideration of TAVI. Only 27% of patients referred to a focused TAVI clinic for surgical consideration underwent TAVI. In addition, 14% of patients declined to undergo TAVI and 11% of patients died during the work up process. These findings highlight the importance of careful screening to maximize resource utilization at TAVI clinics. Furthermore, adequate resources to optimize assessment of potential candidates may improve clinical outcomes during the waiting period.
402
Canadian Cardiovascular Society (CCS) CCS410 Poster OUTCOMES AND REGISTRIES IN CVD Monday, October 25, 2010 406
WEIGHT GAIN IS NOT ALWAYS DETRIMENTAL TO HEART RATE VARIABILITY IN PATIENTS WITH DIABETES AFTER CORONARY ARTERY BYPASS SURGERY V Valiquette-Trépanier, G Salamin, P Brassard, J Després, OF Bertrand, N Alméras, O Costerousse, P Poirier Québec, Québec BACKGROUND: Rosiglitazone, an oral anti-diabetic drug, is associated with weight gain while obesity is associated with altered heart rate variability (HRV). However, it is unknown whether or not weight gain resulting from rosiglitazone therapy is associated with changes in HRV. CONCLUSION: Our results suggest that heart rate variability in patients with diabetes after coronary artery bypass surgery is not altered by rosiglitazone therapy despite a significant increase in body weight which is entirely explained by an increase in subcutaneous adiposity.
ARTERIAL ACCESS SITE WITHIN THE CANADIAN ANTICOAGULANT PERCUTANEOUS CORONARY INTERVENTION REGISTRY (CAPCIR)
407
R Welsh, AJ DellaSiega, J Déry, N Fam, E Schampaert, RH Zimmermann, A Fung, M Hervas-Malo, B Rose Edmonton, Alberta Prior registry data and retrospective analysis from clinical trials had suggested a benefit of radial arterial access compared to femoral arterial access in patients undergoing percutaneous coronary intervention (PCI). Despite this, there are limited rigorous data addressing this in a prospective fashion within patients in Canada. Accordingly we assessed arterial access site
F Bonenfant, DH Do, S Lepage, B Essadiqi, M Brochu, P Farand Sherbrooke, Québec Exercise echocardiography (EE) is an accurate non-invasive test to detect inducible ischemia in patients with coronary artery disease (CAD). Previous studies have already shown its good prognostic value. Our center has recently integrated the EE in its clinical exams for CAD investigation.
Can J Cardiol Vol 26 Suppl D October 2010
RAPID LEARNING CURVE WITH GOOD CLINICAL RESULTS OF A NEW EXERCISE ECHOCARDIOGRAPHY PROGRAM
87D
Abstracts Consequently, the number of EE has considerably increased in the last few years. Our objective was to assess the one year prognostic value of EE at our institution. At our center, EE has an excellent negative predictive value. False negatives, although rare, are more common in patients with a history of past revascularisation reflecting the higher pretest probability. Special attention should be given to this group of patients. EE is an accurate exam for CAD prognostic evaluation and requires fewer investments than other second line non invasive stratification exams. This study shows the rapid learning curve of an EE program with good clinical results. These results could be rapidly achieved in other centers especially in a time of scarce resources and restricted supply of medical isotopes.
408
OUTCOME OF PATIENTS SUBJECTED TO MILD THERAPEUTIC HYPOTHERMIA AFTER SUCCESSFUL RESUSCITATION FROM CARDIAC ARREST M Bachand, M Houle, C St-Pierre, P Farand Sherbrooke, Québec BACKGROUND: Despite significant advances in the treatment of heart disease, the outcome of patients experiencing sudden cardiac arrest (SCA) remains poor. Among survivors of SCA, only 20% have a favourable neurologic outcome at hospital discharge. Several studies have shown that mild therapeutic hypothermia markedly mitigates brain damage after SCA. A cooling protocol (involving infusion of refrigerated fluids) for inducing mild hypothermia in survivors of SCA has been implemented in 2006 at our center (CHUS). The goal of our study was to document the outcome of these patients. CONCLUSION: Despite the fact that current guidelines encourage the use of TH for all patients successfully resuscitated, it remains a recommendation based on weaker evidences for patients with factors known to be associated with a poor outcome. Our results question the use of TH for these patients and we believe that the use of cooling protocol at our center should be restrained to the patients presenting with a ventricular tachyarrhythmia as the initial rhythm. Moreover, the large number of patients transferred from other hospitals in our study underscores the importance of starting the cooling at the referent center whenever possible. Finally, our complication rates appear to be similar to those mentioned in the literature, except that we had more cases of pulmonary congestion.
409
SUCCESSFUL INDUCED HYPOTHERMIA POST-CARDIAC ARREST: EVALUATING PROTOCOL TO EXPAND THERAPEUTIC SCOPE M Chan, C Hoffman, W Hui, DJ Kutsogiannis, P Topipat, R Williams Edmonton, Alberta BACKGROUND: Induced hypothermia (IH) improves outcomes, using stringent selection criteria, thus the American Heart Association recommends IH for out-of-hospital cardiac arrest when VF is the initial cardiac rhythm. Systematic reviews demonstrating positive outcomes only included studies where cooling was initiated within 6 hours of arrest. Therefore, investigations need to establish defined protocol for IH to expand its scope. Primarily, we evaluated our IH protocol in terms of survival and neurological outcome, comparing IH patients to matched (by GCS) controls. Our secondary objective was to gain insights about benefits of IH in relation to described selection criteria and protocols. CONCLUSION: IH provided survival benefit when considering patients of similar neurological status on admission. IH may benefit patients who do not meet currently recommended selection criteria. IH patients arresting in-hospital died (27.3%) less often than those arresting out-of-hospital (66.6%) and those without IH (76.2% in controls with GCS under 7). IH patients with initial rhythms other than VF also seemed to derive benefit (65.2% vs 76.2% death in controls with GCS under 7), while those with non-witnessed arrests had similar survival (76.9% deaths) to the controls with similar GCS. In IH protocols, there should also be consideration of the timing of IH initiation, with 6 hours perhaps being a critical threshold. More studies with long-term follow up are required to better understand the neurological outcomes.
88D
411
SAFETY OF AN ACCELERATED TRANSOESOPHAGEAL STRESS ECHOCARDIOGRAPHY IN THE PREOPERATIVE EVALUATION OF HIGH RISK SEVERELY OBESE SUBJECTS AWAITING BARIATRIC SURGERY S Legault, M Sénéchal, S Bergeron, M Tessier, M Arsenault, J Guimond, P Poirier Québec, Québec Severe obesity is associated with an increased risk of coronary artery disease (CAD). Bariatric surgery is an effective procedure for long term weight management as well as reduction of comorbidities. Preoperative evaluation of cardiac operative risk may often be necessary but unfortunately standard imaging techniques are often suboptimal in these subjects. The purpose of this study was to demonstrate the feasibility and safety of transoesophageal dobutamine stress echocardiography (TE-DSE) using an adapted accelerated dobutamine infusion protocol in severely obese subjects with comorbidities being evaluated for bariatric surgery for assessing the presence of myocardial ischemia. In conclusion, TE-DSE with an accelerated protocol is a safe and well tolerated imaging technique for the evaluation of suspected myocardial ischemia and cardiac operative risk in severely obese patients awaiting bariatric surgery.
412
PERCUTANEOUS TRANSLUMINAL SEPTAL MYOCARDIAL ABLATION IN HYPERTROPHIC OBSTRUCTIVE CARDIOMYOPATHY – ACUTE AND MEDIUM-TERM FOLLOW-UP T Hamid, M Luckie, HM Hadi, R Khattar Manchester, United Kingdom BACKGROUND: Percutaneous trans-luminal septal myocardial ablation (PTSMA) is an alternative therapeutic method to the gold standard surgical myectomy in the treatment of left ventricular outflow tract (LVOT) obstruction in patients with hypertrophic obstructive cardiomyopathy (HOCM). PTSMA is performed by injecting alcohol into a target septal branch of the left anterior descending (LAD) coronary artery. Here, we report the acute and medium-term clinical outcomes of patients undergoing PTSMA for symptomatic HOCM in a single tertiary centre in the United Kingdom (UK). CONCLUSION: PTSMA is an effective non-surgical technique for treatment of symptoms related to LVOT obstruction in HOCM. Medium-term follow-up demonstrates persistent reduction in LVOT obstruction and improvement in NYHA functional class. Conduction defects requiring permanent pacemaker implantation may occur. Long-term studies of larger populations are necessary in order to determine the prognostic significance of the procedure.
413
THE CARDIOVASCULAR DISEASE BURDEN IN A COHORT OF METIS PERSONS, COMPARED TO THE REST OF THE POPULATION OF ONTARIO CL Atzema, J Klein-Geltink, M Gravelle, E Asllani, L Pigeau, J MacQuarrie Toronto, Ontario BACKGROUND: The burden of cardiovascular disease in the Métis is unknown. We examined the rates of four major cardiovascular diseases in the Métis, including acute coronary syndromes (ACS), congestive heart failure (CHF), cerebrovascular disease (CVD), and atrial fibrillation, relative to the rest of the Ontario population, as well as associated outcomes. CONCLUSION: The burden of cardiovascular disease was significantly higher in the Métis persons in this cohort, including much higher rates of ACS and atrial fibrillation in particular. In Métis with CHF, hospital readmission rate was double that the rest of the population, but no differences were found for the other diseases. Higher mortality rates were found only in patients with atrial fibrillation. Public Health Agency of Canada (PHAC)
Can J Cardiol Vol 26 Suppl D October 2010
Abstracts
414
MANAGEMENT OF RISK FACTORS AMONG AMBULATORY PATIENTS AT HIGH CARDIOVASCULAR RISK IN CANADA: CAN WE DO BETTER? E Elbarasi, SG Goodman, RT Yan, A Casanova, M Tan, DG Hackam, LA Leiter, A Langer, AT Yan Toronto, Ontario BACKGROUND: Risk factor modification is an important aspect of the management of cardiovascular disease, and is supported by clinical trials and recommended by practice guidelines. Several cross-sectional studies have evaluated the extent to which guideline-recommended treatment targets are attained in ambulatory patients with cardiovascular disease. However, there are limited longitudinal data on the temporal changes in the attainment of these targets among ambulatory patients with cardiovascular disease in Canada. CONCLUSION: A substantial proportion of patients without 6-month follow-up did not attain guideline-recommended BP and LDL-C targets at baseline. Although there were improvements in blood pressure and lipid control at 6 months among patients with follow-up, the majority still failed to achieve both optimal blood pressure and lipid targets. Effective ongoing quality improvement measures for management of cardiovascular risk factors are warranted.
415
A CATCH ALBERTA INTER-PROFESSIONAL INDO-ASIAN CARDIOVASCULAR HEALTH AND MANAGEMENT PROGRAM M Coleman, K Barnachea, J Hefferton, J Koppel, W Mainville, A Wilson, H Yau, B Hatoum, S Wiens, C Cox, M Gukert, N Hassam, CA Jones Calgary, Alberta BACKGROUND: Indo-Asians (IA) are predisposed to hypertension, dyslipidemia, diabetes, obesity, and cardiovascular disease (CVD). A recent study of CVD risk factors in a Calgary, Alberta IA population, identified poor risk factor control and follow-through with treatment recommendations, despite the high level of satisfaction with the program. The purpose of this study is to consult this same IA community to identify the determinants of the poor risk factor control and follow-up. And, based on these findings, pilot the implementation of a CVD prevention program that includes risk factor screening and education sessions targeted to the identified needs of the community members. CONCLUSION: Many IA clients are aware of their CVD risk. For many, management of risk factors is still poor. Client interest in lifestyle education is high; therefore, such education shows promise in improving CVD risk factor management. Further CVD risk screening/education sessions are required in multiple community settings in order to make a greater impact on CVD prevention in the IA population.
Canadian Cardiovascular Society (CCS) CCS415 Poster MANAGEMENT OF BRADY AND TACHYARRHYTHMIAS Monday, October 25, 2010 418
CIRCUMFERENTIAL VS SEGMENTAL ANTRAL ABLATION FOR PAROXYSMAL ATRIAL FIBRILLATION RW Sy, LJ Gula, P Leong-Sit, R Yee, A Krahn, GJ Klein, AC Skanes London, Ontario BACKGROUND: Circumferential antral ablation is widely used for treating paroxysmal AF. However, complete encirclement of the pulmonary vein (PV) antra may not be necessary. We compared a segmental approach limiting ablation to segments of the antra required for PV-LA conduction to a standard circumferential approach.
Can J Cardiol Vol 26 Suppl D October 2010
CONCLUSION: Compared to circumferential ablation, segmental antral ablation achieves similar success rates with shorter procedural and ablation times. A prospective randomized trial is warranted.
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ELECTROPHYSIOLOGIC CHARACTERISTICS AND ABLATION OF ATRIAL TACHYCARDIA AFTER CIRCUMFERENTIAL ABLATION FOR ATRIAL FIBRILLATION: IMPLICATIONS REGARDING ITS MECHANISMS JP Man, MW Deyell, V Bhole, S Chakrabarti, JA Yeung-Lai-Wah Vancouver, British Columbia BACKGROUND: Atrial tachycardia (AT) is a significant sequel of circumferential ablation (CA) for atrial fibrillation (AF). There are limited data regarding activation mapping and ablation of AT. The aim of this review is to determine whether AT results from deficiencies in the line lesions or occur de novo, using activation mapping techniques. Better characterization of recurrent AT would assist in initial ablation. CONCLUSION: ATs post-CA occur de novo remote from the line lesions in CA in a slim majority of cases; however, recovery of previously created line lesions also contributes to a significant minority of ATs. Concomitant RA isthmus ablation would reduce AT as there is a significant proportion of patients with right sided isthmus-dependent flutters. Correct mapping is crucial in determining the mechanism of AT because of the large variability in causes.
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ARE TRADITIONAL SVT ENTRAINMENT CRITERIA VALID TO DIFFERENTIATE ATYPICAL AVNRT WITH LONG RETROGRADE CONDUCTION TIME FROM AVRT USING A SLOWLY CONDUCTING SEPTAL ACCESSORY PATHWAY? MT Bennett, P Leong-Sit, LJ Gula, AC Skanes, A Krahn, GJ Klein London, Ontario RV entrainment criteria have been published to distinguish atypical AV node reentrant tachycardia (AVNRT) from atrio-ventricular reentrant tachycardia (AVRT) using a septal accessory pathway. In atypical AVNRT, the difference between the post pacing interval and the tachycardia cycle length (PPI-TCL) is greater than 115 msec. Similarly, the difference in the ventriculo-atrial interval during pacing and tachycardia (StimA-VA) is greater than 85 msec in atypical AVNRT but less in AVRT. These criteria have not been adequately validated in patients with slowly conducting and decremental retrograde pathways. These preliminary data suggest that the traditional ventricular entrainment criteria for SVT mechanism will not be reliable for differentiating atypical AVNRT with a long VA conduction time from AVRT using a slowly conducting or decremental retrograde septal accessory pathway.
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ABLATION CATHETER IMPEDANCE DECREASES IN THE PULMONARY VEIN AND LEFT ATRIUM DURING AN ATRIAL FIBRILLATION ABLATION PROCEDURE NA Cromie, O Sultan, S Agarwal, R Ayou, L Chen, P Novak, LD Sterns, R Leather, AS Tang Victoria, British Columbia BACKGROUND: Pulmonary vein (PV) isolation is a commonly performed curative procedure for atrial fibrillation. PV stenosis is a complication that occurs in 1% of patients. There is a higher risk of stenosis when ablation is performed within the vein, rather than its antrum. Impedance changes occur between the left atrium (LA) and PV and are frequently used to direct application of radiofrequency ablation. If these impedances changed over time it could lead to inadvertent ablation within the PV increasing the risk of stenosis. This study was designed to monitor impedance changes in the PV and LA during PV isolation. CONCLUSION: During PV isolation, there is a significant drop in impedance within the PVs, the PV os and the LA body. The average impedance for the combined PVmid and PVdist fell from baseline (264Ω) to 248Ω after the first ipsilateral vein isolation and further after all PVs
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