- Email: [email protected]
PREDICTORS OF PACEMAKER IMPLANTATION AND LONG-TERM PACEMAKER DEPENDENCY POST CARDIAC SURGERY
Abstracts
surveillance were included. Data was accessed 04-14-16. The percentage of patients whose ICD’s NID were programmed to 30/40 at their most recent CARELINK transmission was documented. This percentage was then stratified by implant year, province, and number of patients per clinic enrolled in CARELINK. RESULTS: 1418 of the 2265 patients from 47 clinics were programmed to an NID of at least 30/40. The percentage of patients programmed to an NID of at least 30/40 increased incrementally dependent on implant year (figure) and differed significantly by province ranging from 0% to 93%. There was no relationship between the number of patients enrolled in CARELINK in each specific clinic and the percentage of patients with an NID of at least 30/40. CONCLUSIONS: Changes in ICD programming is most likely to occur at implantation than at clinic visits. Across Canada, there is a significant variation in the percentage of patients who are programmed to an NID of at least 30/40.
S141
(OR) were reported for dichotomous variables. Five studies (4 retrospective and 1 prospective non-randomized) involving 1636 adult patients were identified. MRI compatible pacemakers were deployed in 692 patients. Baseline characteristics were similar between both groups. MRI group had a trend for higher overall complications in comparison to conventional group (7% vs. 2%, OR 2.99 (95% confidence interval [CI] 0.97; 9.24), p¼0.06) and higher rates of cardiac tamponade/ pericardial effusion (3% vs. 1%, OR 3.97 (95% CI 0.83; 18.90), p¼0.08). The rate of pacemaker leads dislodgement (atrial or ventricular) was significantly higher in the MRI group (4% vs. 1%, OR 3.67 (95% CI 1.59; 8.43), p¼0.002). CONCLUSION: In this meta-analysis, signals were seen favoring the safety of conventional pacemakers in comparison to MRI compatible pacemakers for overall complications including cardiac tamponade/pericardial effusion but neither was statistically significant because of low event rates. The rate of pacemaker leads dislodgement was significantly higher in the MRI group. More high-quality data are required to further assess the safety of MRI compatible pacemakers.
131 PREDICTORS OF PACEMAKER IMPLANTATION AND LONG-TERM PACEMAKER DEPENDENCY POST CARDIAC SURGERY A Merdad, C Khoo, CM Seifer, RC Arora, BM Heibert, WF McIntyre Winnipeg, Manitoba BACKGROUND:
130 IS THERE AN INCREASED COMPLICATION RATE WITH MRI-COMPATIBLE PACEMAKERS IN COMPARISON TO CONVENTIONAL PACEMAKERS? A META-ANALYSIS M Shurrab, S Haj-Yahia, A Kaoutskaia, T Singarajah, C Lau, I Lashevsky, D Newman, E Crystal Nablus, Palestine BACKGROUND:
Magnetic resonance imaging (MRI) usage for diagnostic purposes is increasing exponentially. Hence the use of MRI-compatible pacing systems has expanded significantly. MRI-compatible pacing systems require significant changes in hardware. In this meta-analysis, we examine the safety of MRI compatible pacing systems in comparison to conventional systems. METHODS/RESULTS: An electronic search was performed using major databases including studies that compared the outcomes of interest between patients receiving MRI compatible pacemakers (MRI group) versus conventional pacemakers (conventional group). All references were reviewed manually. Primary outcome was overall complication rate. Odds ratios
Patients undergoing cardiac surgery are at risk of developing conduction abnormalities and often require permanent pacemaker (PPM) implantation. This occurs in 1.4-8.5% of cardiac surgery patients. We aimed to identify risk factors for early pacemaker implantation after cardiac surgery and predictors of long-term pacemaker dependency. METHODS: We conducted a retrospective analysis of 6113 patients who underwent cardiac surgery. Kaplan-Meier analysis was done to assess freedom from PPM Dependency at follow-up. Variables were compared using Chi-Square or Fisher’s Exact Test and Mann-Whitney Test. A multivariable logistic regression model was developed to look for independent risk factors for PPM implantation and long-term dependency. RESULTS: One hundred and forty patients (1.85%) underwent PPM implantation after surgery. Complete heart block (CHB) was the most common indication (57%), followed by sinus node dysfunction (35.2%), and atrial fibrillation with slow ventricular response (7.8%). Multivariable analysis showed that older age, aortic valve surgery and mitral valve surgery, were independent risk factors for PPM implantation. Data on long-term dependency was available in 116 patients and 32.8% were dependent. The mean follow-up period was 2.3 years. Multivariate analysis showed that CHB and combined mitral and aortic valve surgery, were independent risk factors for PPM dependency at long-term follow-up.
S142 CONCLUSION:
Independent risk factors for PPM implantation include older age, aortic and mitral valve surgery. Patients at an increased risk for long-term pacemaker dependency include those with postoperative CHB and those undergoing combined valve surgeries.
Canadian Cardiovascular Society (CCS) ePoster GLIMPSES AT FUTURE THERAPIES: HEART FAILURE BASIC SCIENCE Saturday, October 22, 2016
Canadian Journal of Cardiology Volume 32 2016
WAT communicate and that this signalling pathway plays a role in regulating cardiac insulin sensitivity. The importance of this intra-organ communication in HF is currently being investigated.
133 VEGF-INDUCED MYOCARDIAL CELL ANTIAPOPTOTIC EVENTS REQUIRES S100A6 SIGNALING J Tsoporis, S Izhar, V Salpeas, IK Rizos, TG Parker Toronto, Ontario
132 THE EFFECTS OF ADIPOCYTE-SPECIFIC ADIPOSE TRIGLYCERIDE LIPASE DELETION ON CARDIAC FUNCTION N Parajuli, S Bairwa, EE Kershaw, JR Dyck Edmonton, Alberta BACKGROUND:
Although diabetes is a risk factor for heart failure (HF), it is clear from the existing literature that the converse is also true and that HF itself induces systemic insulin resistance. Of interest, studies in mice and humans have demonstrated that inflammation of white adipose tissue (WAT) is induced by HF and that this inflammation occurs as a result of excessive WAT lipolysis. Moreover, recent work has shown that HF induces excessive WAT lipolysis via increased activation of adipose triglyceride lipase (ATGL; the ratelimiting enzyme involved in mediating lipolysis) and that this leads to WAT inflammation. Thus, we hypothesized that HFinduced WAT lipolysis and inflammation also contributes to cardiac insulin resistance, and that this intra-organ signalling axis contributes to worsening cardiac function by reducing cardiac glucose utilization during HF. METHODS/RESULTS: To address this, we prevented adiposespecific ATGL-mediated lipolysis in HF using adipose tissuespecific ATGL-deficient mice (atATGL-KO) mice that were generated after crossing B6N.129-Pnpla2tm1Eek (atgl-flox) with B6N.FVB.Tg (Adipoq-Cre)1evr/J mice. For initial characterization, hearts were obtained from atATGL-KO and atgl-floxed (control) mice. Western blot analysis shows that NF-kb expression is increased in WAT from control mice with HF compared to non-HF controls, suggesting WAT inflammation is increased in mice with HF. In addition, hearts from at ATGL-KO mice have increased insulin-dependent cardiac glucose uptake compared to controls, suggesting improved cardiac insulin sensitivity in the KO mice. Consistent with improved insulin sensitivity, a significant decrease in Akt (w2 fold) (p<0.05) was observed in hearts from atATGL-KO mice compared to controls. CONCLUSION: The increase in cardiac insulin sensitivity in the hearts from atATGL-KO mice suggests that the heart and
BACKGROUND:
Coronary artery bypass graft (CABG)-related cardiomyocyte apoptosis can result from overproduction of reactive oxygen species (ROS) following restoration of coronary blood flow. A number of endothelial markers including vascular endothelial growth factor (VEGF) may be released post CABG and may modulate the cardiomyocyte apoptotic response. We aimed to determine a possible role for VEGF in CABG-induced cardiomyocyte apoptosis. METHODS: During CABG surgery with cardiopulmonary bypass (CPB), sequential biopsies were taken from the right atrial appendage (RAA) before CPB and after aortic cross clamp release. The apoptotic markers caspase 3 activity, BAX, BCL2 and the BAX/BCL2 mRNA ratio, along with VEGF, the VEGF receptors VEGFR2 (KDR) and VEGFR3 (FLT-1) mRNA and protein were assessed. RESULTS: The patient group consisted of 15 women and 42 men with a mean S.E. age of 66.571.78 and 63.021.15 years respectively, CPB was associated with increased myocyte apoptosis as assessed by a 3.5 fold increase in the BAX/BCL2 mRNA ratio and a 15 per cent increase in caspase 3 activity in the RAA. VEGF and VEGFR3 mRNA and protein in the RAA were increased approximately 2-3 fold. There were negative correlations between RAA VEGF and BAX/BCL2 mRNAs (r¼-0.279, p¼0.032) and RAA VEGFR3 and BAX/BCL2 mRNAs (r¼-0.494, p<0.001). Interestingly, there were positive correlations between RAA VEGF and the anti-apoptotic S100 calcium binding protein S100A6 (r¼0.471, p<0.001) and RAA VEGFR3 and S100A6 (r¼0.437, p<0.001). Mechanistically, treatment of cultured neonatal rat neonatal cardiomyocytes with VEGF (10 nM) increased S100A6 protein and mRNA 2-3 fold and inhibited the H2O2induced increase in the BAX/BCL2 ratio by 65%. Whereas, in the presence of S100A6 siRNA, VEGF had no effect on H2O2-induced cardiomyocyte apoptosis. CONCLUSION: VEGF ligand binding to VEGFR3 exerts cardiac protection via anti-apoptotic effects dependent on S100A6 signaling.
surveillance were included. Data was accessed 04-14-16. The percentage of patients whose ICD’s NID were programmed to 30/40 at their most recent CARELINK transmission was documented. This percentage was then stratified by implant year, province, and number of patients per clinic enrolled in CARELINK. RESULTS: 1418 of the 2265 patients from 47 clinics were programmed to an NID of at least 30/40. The percentage of patients programmed to an NID of at least 30/40 increased incrementally dependent on implant year (figure) and differed significantly by province ranging from 0% to 93%. There was no relationship between the number of patients enrolled in CARELINK in each specific clinic and the percentage of patients with an NID of at least 30/40. CONCLUSIONS: Changes in ICD programming is most likely to occur at implantation than at clinic visits. Across Canada, there is a significant variation in the percentage of patients who are programmed to an NID of at least 30/40.
S141
(OR) were reported for dichotomous variables. Five studies (4 retrospective and 1 prospective non-randomized) involving 1636 adult patients were identified. MRI compatible pacemakers were deployed in 692 patients. Baseline characteristics were similar between both groups. MRI group had a trend for higher overall complications in comparison to conventional group (7% vs. 2%, OR 2.99 (95% confidence interval [CI] 0.97; 9.24), p¼0.06) and higher rates of cardiac tamponade/ pericardial effusion (3% vs. 1%, OR 3.97 (95% CI 0.83; 18.90), p¼0.08). The rate of pacemaker leads dislodgement (atrial or ventricular) was significantly higher in the MRI group (4% vs. 1%, OR 3.67 (95% CI 1.59; 8.43), p¼0.002). CONCLUSION: In this meta-analysis, signals were seen favoring the safety of conventional pacemakers in comparison to MRI compatible pacemakers for overall complications including cardiac tamponade/pericardial effusion but neither was statistically significant because of low event rates. The rate of pacemaker leads dislodgement was significantly higher in the MRI group. More high-quality data are required to further assess the safety of MRI compatible pacemakers.
131 PREDICTORS OF PACEMAKER IMPLANTATION AND LONG-TERM PACEMAKER DEPENDENCY POST CARDIAC SURGERY A Merdad, C Khoo, CM Seifer, RC Arora, BM Heibert, WF McIntyre Winnipeg, Manitoba BACKGROUND:
130 IS THERE AN INCREASED COMPLICATION RATE WITH MRI-COMPATIBLE PACEMAKERS IN COMPARISON TO CONVENTIONAL PACEMAKERS? A META-ANALYSIS M Shurrab, S Haj-Yahia, A Kaoutskaia, T Singarajah, C Lau, I Lashevsky, D Newman, E Crystal Nablus, Palestine BACKGROUND:
Magnetic resonance imaging (MRI) usage for diagnostic purposes is increasing exponentially. Hence the use of MRI-compatible pacing systems has expanded significantly. MRI-compatible pacing systems require significant changes in hardware. In this meta-analysis, we examine the safety of MRI compatible pacing systems in comparison to conventional systems. METHODS/RESULTS: An electronic search was performed using major databases including studies that compared the outcomes of interest between patients receiving MRI compatible pacemakers (MRI group) versus conventional pacemakers (conventional group). All references were reviewed manually. Primary outcome was overall complication rate. Odds ratios
Patients undergoing cardiac surgery are at risk of developing conduction abnormalities and often require permanent pacemaker (PPM) implantation. This occurs in 1.4-8.5% of cardiac surgery patients. We aimed to identify risk factors for early pacemaker implantation after cardiac surgery and predictors of long-term pacemaker dependency. METHODS: We conducted a retrospective analysis of 6113 patients who underwent cardiac surgery. Kaplan-Meier analysis was done to assess freedom from PPM Dependency at follow-up. Variables were compared using Chi-Square or Fisher’s Exact Test and Mann-Whitney Test. A multivariable logistic regression model was developed to look for independent risk factors for PPM implantation and long-term dependency. RESULTS: One hundred and forty patients (1.85%) underwent PPM implantation after surgery. Complete heart block (CHB) was the most common indication (57%), followed by sinus node dysfunction (35.2%), and atrial fibrillation with slow ventricular response (7.8%). Multivariable analysis showed that older age, aortic valve surgery and mitral valve surgery, were independent risk factors for PPM implantation. Data on long-term dependency was available in 116 patients and 32.8% were dependent. The mean follow-up period was 2.3 years. Multivariate analysis showed that CHB and combined mitral and aortic valve surgery, were independent risk factors for PPM dependency at long-term follow-up.
S142 CONCLUSION:
Independent risk factors for PPM implantation include older age, aortic and mitral valve surgery. Patients at an increased risk for long-term pacemaker dependency include those with postoperative CHB and those undergoing combined valve surgeries.
Canadian Cardiovascular Society (CCS) ePoster GLIMPSES AT FUTURE THERAPIES: HEART FAILURE BASIC SCIENCE Saturday, October 22, 2016
Canadian Journal of Cardiology Volume 32 2016
WAT communicate and that this signalling pathway plays a role in regulating cardiac insulin sensitivity. The importance of this intra-organ communication in HF is currently being investigated.
133 VEGF-INDUCED MYOCARDIAL CELL ANTIAPOPTOTIC EVENTS REQUIRES S100A6 SIGNALING J Tsoporis, S Izhar, V Salpeas, IK Rizos, TG Parker Toronto, Ontario
132 THE EFFECTS OF ADIPOCYTE-SPECIFIC ADIPOSE TRIGLYCERIDE LIPASE DELETION ON CARDIAC FUNCTION N Parajuli, S Bairwa, EE Kershaw, JR Dyck Edmonton, Alberta BACKGROUND:
Although diabetes is a risk factor for heart failure (HF), it is clear from the existing literature that the converse is also true and that HF itself induces systemic insulin resistance. Of interest, studies in mice and humans have demonstrated that inflammation of white adipose tissue (WAT) is induced by HF and that this inflammation occurs as a result of excessive WAT lipolysis. Moreover, recent work has shown that HF induces excessive WAT lipolysis via increased activation of adipose triglyceride lipase (ATGL; the ratelimiting enzyme involved in mediating lipolysis) and that this leads to WAT inflammation. Thus, we hypothesized that HFinduced WAT lipolysis and inflammation also contributes to cardiac insulin resistance, and that this intra-organ signalling axis contributes to worsening cardiac function by reducing cardiac glucose utilization during HF. METHODS/RESULTS: To address this, we prevented adiposespecific ATGL-mediated lipolysis in HF using adipose tissuespecific ATGL-deficient mice (atATGL-KO) mice that were generated after crossing B6N.129-Pnpla2tm1Eek (atgl-flox) with B6N.FVB.Tg (Adipoq-Cre)1evr/J mice. For initial characterization, hearts were obtained from atATGL-KO and atgl-floxed (control) mice. Western blot analysis shows that NF-kb expression is increased in WAT from control mice with HF compared to non-HF controls, suggesting WAT inflammation is increased in mice with HF. In addition, hearts from at ATGL-KO mice have increased insulin-dependent cardiac glucose uptake compared to controls, suggesting improved cardiac insulin sensitivity in the KO mice. Consistent with improved insulin sensitivity, a significant decrease in Akt (w2 fold) (p<0.05) was observed in hearts from atATGL-KO mice compared to controls. CONCLUSION: The increase in cardiac insulin sensitivity in the hearts from atATGL-KO mice suggests that the heart and
BACKGROUND:
Coronary artery bypass graft (CABG)-related cardiomyocyte apoptosis can result from overproduction of reactive oxygen species (ROS) following restoration of coronary blood flow. A number of endothelial markers including vascular endothelial growth factor (VEGF) may be released post CABG and may modulate the cardiomyocyte apoptotic response. We aimed to determine a possible role for VEGF in CABG-induced cardiomyocyte apoptosis. METHODS: During CABG surgery with cardiopulmonary bypass (CPB), sequential biopsies were taken from the right atrial appendage (RAA) before CPB and after aortic cross clamp release. The apoptotic markers caspase 3 activity, BAX, BCL2 and the BAX/BCL2 mRNA ratio, along with VEGF, the VEGF receptors VEGFR2 (KDR) and VEGFR3 (FLT-1) mRNA and protein were assessed. RESULTS: The patient group consisted of 15 women and 42 men with a mean S.E. age of 66.571.78 and 63.021.15 years respectively, CPB was associated with increased myocyte apoptosis as assessed by a 3.5 fold increase in the BAX/BCL2 mRNA ratio and a 15 per cent increase in caspase 3 activity in the RAA. VEGF and VEGFR3 mRNA and protein in the RAA were increased approximately 2-3 fold. There were negative correlations between RAA VEGF and BAX/BCL2 mRNAs (r¼-0.279, p¼0.032) and RAA VEGFR3 and BAX/BCL2 mRNAs (r¼-0.494, p<0.001). Interestingly, there were positive correlations between RAA VEGF and the anti-apoptotic S100 calcium binding protein S100A6 (r¼0.471, p<0.001) and RAA VEGFR3 and S100A6 (r¼0.437, p<0.001). Mechanistically, treatment of cultured neonatal rat neonatal cardiomyocytes with VEGF (10 nM) increased S100A6 protein and mRNA 2-3 fold and inhibited the H2O2induced increase in the BAX/BCL2 ratio by 65%. Whereas, in the presence of S100A6 siRNA, VEGF had no effect on H2O2-induced cardiomyocyte apoptosis. CONCLUSION: VEGF ligand binding to VEGFR3 exerts cardiac protection via anti-apoptotic effects dependent on S100A6 signaling.