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Intra-Thoracic Impedance and the Onset of Atrial and Ventricular Tachyarrhythmias: A Meta-Analysis
S70 Journal of Cardiac Failure Vol. 23 No. 8S August 2017
Electrophysiology/Arrhythmias 185
187
Arrhythmia Burden and Its Effect on in-Hospital Outcomes in Patients with Hypertrophic Obstructive Cardiomyopathy Siva Sagar Taduru1, Shubha Deep Roy1, Dushyant Ramakrishnan2, Alankrita Taneja3, Laith Derbas1, Anweshan Samanta1, Paramdeep Baweja1; 1University of Missouri Kansas City, Kansas City, Missouri; 2Osmania Medical College, Hyderabad, India; 3Armed Forces Medical College, Pune, India
Intra-Thoracic Impedance and the Onset of Atrial and Ventricular Tachyarrhythmias: A Meta-Analysis Hossam Abubakar1, Mohammed Osman2, Emmanuel Akintoye1, Ahmed Subahi1, Aiden Abidov1,3; 1Wayne State University, Detroit, Michigan; 2Hurley Medical Center/Michigan State University, Flint, Michigan; 3John D. Dingell VA Medical Center, Detroit, Michigan
Background: Hypertrophic obstructive cardiomyopathy (HOCM) is known to be associated with supraventricular and ventricular arrhythmias. The burden of such arrhythmias and its effect on in-hospital outcomes in patients hospitalized with HOCM is not clear. Objectives: Our aim was to identify the burden of arrhythmia and its effect on in-hospital mortality in patients hospitalized with HOCM in recent years (2008 - 2014) using National Inpatient Sample (NIS). Methods: We identified patients who were hospitalized with primary diagnosis of HOCM using International Classification of Diseases codes - 9th edition (ICD-9) code 425.11. We identified presence of arrhythmias in this group using appropriate ICD-9 codes. We used multivariate binary logistic regression and multivariate linear regression to identify predictors associated with in-hospital mortality, length of stay (LOS), and total hospital charges respectively. Results: We identified 8534 patients discharged with diagnosis of HOCM. A total of 2880 (33.7%) patients had concomitant diagnosis of any arrhythmia. Among patients with HOCM, 235 (2.8%) patients had ventricular fibrillation (VF), 2025 (23.7%) had atrial fibrillation (AF), 324 (3.8%) had atrial flutter (AFL), 347 (4.1%) had atrioventricular nodal blocks, and 268 (3.1%) had premature beats. The in-hospital mortality in arrhythmia group was 2.6% compared to 1.5% in non-arrhythmia group. We found that only VF had significant effect on in-hospital mortality with these patients having adjusted odds ratio (AOR) of 19.41 (95% CI = 10.39 - 36.25, P < .001) when compared to patients without VF. Median length of stay in arrhythmia group was 5 days compared to 3 days in non-arrhythmia group. Arrhythmias predicting increased LOS included VF (average of 3.63 days longer), AF (average of 0.61 days longer), and AFL (average of 6.95 days longer). Mean total charges of arrhythmia group were $122,503 compared to $76,435 in non-arrhythmia group. Arrhythmias predicting increased total hospitalization charges included VF (increased by an average of $70,572), and AFL (increased by an average of $131,193). Conclusion: About 1/3rd of patients admitted with HOCM had a concomitant diagnosis of arrhythmia. Atrial fibrillation was the most common arrhythmia. Presence of VF was a significant predictor of in-hospital mortality. Presence of VF, AF, AFL increased the LOS, while VF and AFL were associated with increased total hospital charges in patients hospitalized with HOCM.
Background and Purpose: Although Congestive heart failure (CHF) is a presumed culprit for the occurrence of atrial tachyarrhythmias (AT/AF) and ventricular tachyarrhythmias (VT/VF), the relationship between these two disease processes is not completely understood. Technological advances of ICD and CRT-D devices allow correlating changes in the intra-thoracic impedance (TI), an indicator of fluid overload, with the onset of arrhythmic events. In an attempt to attain a better understanding of this relationship, we conducted a meta-analysis of studies that investigated the association between (TI) changes and onset of AT/AF and/or VT/VF in patients with implanted ICD and CRT devices. Methods: We performed a meta-analysis of studies published through January 2017 that reported an association between decrease in the (TI) measured by the OptiVol fluid index (OI) crossing a threshold of 60 ohm-days (previously demonstrated to indicate worsening CHF), and occurrence of AT/AF and VT/VF. Four databases were searched: PubMed, Embase, CINAHL and Cochrane. Effect estimates were extracted from each study in the form of Odds Ratio (OR) and 95% confidence intervals. The OR from individual studies that assessed VT/VF were pooled together using the random effect model to account for between-study variation. The same was done for studies that assessed AT/AF. Heterogeneity between studies was assesed and potential sources of heterogeneity were explored using the metaregression method. Results: From the initially retrieved 602 publications, we defined 8 articles with results of the original research allowing to extract data for the OR calculation. Our pooled sample included 94,666 patients from 4 studies for AT/AF and 23,601 patients from 6 studies for VT/VF. Two studies were included in both analyses. The pooled OR for fluid index threshold crossing of 60 ohm-days was 1.56 (95% CI 1.35, 1.81) for VT/VF (Fig. 1A) and 1.8 (95% CI 1.43, 2.27) for AT/AF (Fig. 1B). Heterogeneity between studies was statistically significant and was not explained by the variables assessed by meta-regression. Conclusion: The findings of our Metaanalysis based on the large pooled population of >110,000 patients, reveal that decreased TI (measured by OI threshold crossing of 60 ohm-days) is a significant risk factor for the onset of AT/AF and VT/VF. Further research is needed to define whether management of subclinical fluid overload guided by the remote monitoring of TI changes, might reduce the incidence of arrhythmic events in patients with implantable devices.
186 Relationship between the Transmural Dispersion of Repolarization and Left Atrial Pressure during Diuresis in a Volume Overloaded State RamaDilip Gajulapalli, Mohamed Alalwani, Deepak Pattanshetty, Wilson Tang; Cleveland Clinic, Cleveland, Ohio Background: Ventricular volume overload causing mechanical wall stress has been suspected of causing exaggeration of transmural dispersion of repolarization. We hypothesized that the T peak to T end interval (Tpe) as measured on the surface electrocardiogram (EKG) and presumed to be the surrogate of transmural dispersion of repolarization is related to measurements by the Swan Ganz (SG) pulmonary artery (PA) catheter indicating the volume status in patients admitted to hospital for presumed acute decompensated heart failure. Methods: Retrospective review of patient records admitted to the heart failure unit at our institution in 2015 for goal directed therapy using Swan Ganz monitoring as well as having a documented EKG at admission and discharge or follow up when they were deemed euvolemic. After de identification and blinding, the Tpe interval as defined by the standard tangent method was measured using electronic calipers. Admission Tpe measurements were then compared to those at discharge or follow up. All clinical characteristics including SG measurements during their treatment are documented for comparison. Results: In a total of 100 subjects, the mean Tpe (milliseconds) during volume overloaded state was 2.43 compared to 2.01 post diuresis or at follow up (P < .001). The mean pulmonary capillary wedge pressure (PCWP) during volume overloaded state was 29.84 mmHg compared to 16.75 mmHg post diuresis (P < .001). There seemed to be a positive trend between the change in Tpe and simultaneous reduction in PCWP (r = 0.16), however the correlation seemed stronger in those patients whose Tpe improved better than the median (r = 0.25) than those who did not improve at all or improved less than the median (r = 0.13). Patients who were paced seemed to have a weaker correlation (r = 0.02) than non-paced subjects (r = 0.21). Patients without a pacer and whose Tpe improved more than the median had the best correlation (r = 0.40) Conclusions: Subjects whose Tpe improved better than median seem to have better correlation between Tpe and PA pressures than those whose Tpe improved marginally or not at all. Non Paced subjects correlated better that paced subjects. Tpe may have a potential in the prediction of volume overloaded state in heart failure patients.
Fig. 1. A. Association of OI threshold crossing of 60 ohm-days with Ventricular Tachyarrhythmias (VT/VF). B. Association of OI threshold crossing of 60 ohm-days with Atrial Tachyarrhythmias (AT/AF).
Electrophysiology/Arrhythmias 185
187
Arrhythmia Burden and Its Effect on in-Hospital Outcomes in Patients with Hypertrophic Obstructive Cardiomyopathy Siva Sagar Taduru1, Shubha Deep Roy1, Dushyant Ramakrishnan2, Alankrita Taneja3, Laith Derbas1, Anweshan Samanta1, Paramdeep Baweja1; 1University of Missouri Kansas City, Kansas City, Missouri; 2Osmania Medical College, Hyderabad, India; 3Armed Forces Medical College, Pune, India
Intra-Thoracic Impedance and the Onset of Atrial and Ventricular Tachyarrhythmias: A Meta-Analysis Hossam Abubakar1, Mohammed Osman2, Emmanuel Akintoye1, Ahmed Subahi1, Aiden Abidov1,3; 1Wayne State University, Detroit, Michigan; 2Hurley Medical Center/Michigan State University, Flint, Michigan; 3John D. Dingell VA Medical Center, Detroit, Michigan
Background: Hypertrophic obstructive cardiomyopathy (HOCM) is known to be associated with supraventricular and ventricular arrhythmias. The burden of such arrhythmias and its effect on in-hospital outcomes in patients hospitalized with HOCM is not clear. Objectives: Our aim was to identify the burden of arrhythmia and its effect on in-hospital mortality in patients hospitalized with HOCM in recent years (2008 - 2014) using National Inpatient Sample (NIS). Methods: We identified patients who were hospitalized with primary diagnosis of HOCM using International Classification of Diseases codes - 9th edition (ICD-9) code 425.11. We identified presence of arrhythmias in this group using appropriate ICD-9 codes. We used multivariate binary logistic regression and multivariate linear regression to identify predictors associated with in-hospital mortality, length of stay (LOS), and total hospital charges respectively. Results: We identified 8534 patients discharged with diagnosis of HOCM. A total of 2880 (33.7%) patients had concomitant diagnosis of any arrhythmia. Among patients with HOCM, 235 (2.8%) patients had ventricular fibrillation (VF), 2025 (23.7%) had atrial fibrillation (AF), 324 (3.8%) had atrial flutter (AFL), 347 (4.1%) had atrioventricular nodal blocks, and 268 (3.1%) had premature beats. The in-hospital mortality in arrhythmia group was 2.6% compared to 1.5% in non-arrhythmia group. We found that only VF had significant effect on in-hospital mortality with these patients having adjusted odds ratio (AOR) of 19.41 (95% CI = 10.39 - 36.25, P < .001) when compared to patients without VF. Median length of stay in arrhythmia group was 5 days compared to 3 days in non-arrhythmia group. Arrhythmias predicting increased LOS included VF (average of 3.63 days longer), AF (average of 0.61 days longer), and AFL (average of 6.95 days longer). Mean total charges of arrhythmia group were $122,503 compared to $76,435 in non-arrhythmia group. Arrhythmias predicting increased total hospitalization charges included VF (increased by an average of $70,572), and AFL (increased by an average of $131,193). Conclusion: About 1/3rd of patients admitted with HOCM had a concomitant diagnosis of arrhythmia. Atrial fibrillation was the most common arrhythmia. Presence of VF was a significant predictor of in-hospital mortality. Presence of VF, AF, AFL increased the LOS, while VF and AFL were associated with increased total hospital charges in patients hospitalized with HOCM.
Background and Purpose: Although Congestive heart failure (CHF) is a presumed culprit for the occurrence of atrial tachyarrhythmias (AT/AF) and ventricular tachyarrhythmias (VT/VF), the relationship between these two disease processes is not completely understood. Technological advances of ICD and CRT-D devices allow correlating changes in the intra-thoracic impedance (TI), an indicator of fluid overload, with the onset of arrhythmic events. In an attempt to attain a better understanding of this relationship, we conducted a meta-analysis of studies that investigated the association between (TI) changes and onset of AT/AF and/or VT/VF in patients with implanted ICD and CRT devices. Methods: We performed a meta-analysis of studies published through January 2017 that reported an association between decrease in the (TI) measured by the OptiVol fluid index (OI) crossing a threshold of 60 ohm-days (previously demonstrated to indicate worsening CHF), and occurrence of AT/AF and VT/VF. Four databases were searched: PubMed, Embase, CINAHL and Cochrane. Effect estimates were extracted from each study in the form of Odds Ratio (OR) and 95% confidence intervals. The OR from individual studies that assessed VT/VF were pooled together using the random effect model to account for between-study variation. The same was done for studies that assessed AT/AF. Heterogeneity between studies was assesed and potential sources of heterogeneity were explored using the metaregression method. Results: From the initially retrieved 602 publications, we defined 8 articles with results of the original research allowing to extract data for the OR calculation. Our pooled sample included 94,666 patients from 4 studies for AT/AF and 23,601 patients from 6 studies for VT/VF. Two studies were included in both analyses. The pooled OR for fluid index threshold crossing of 60 ohm-days was 1.56 (95% CI 1.35, 1.81) for VT/VF (Fig. 1A) and 1.8 (95% CI 1.43, 2.27) for AT/AF (Fig. 1B). Heterogeneity between studies was statistically significant and was not explained by the variables assessed by meta-regression. Conclusion: The findings of our Metaanalysis based on the large pooled population of >110,000 patients, reveal that decreased TI (measured by OI threshold crossing of 60 ohm-days) is a significant risk factor for the onset of AT/AF and VT/VF. Further research is needed to define whether management of subclinical fluid overload guided by the remote monitoring of TI changes, might reduce the incidence of arrhythmic events in patients with implantable devices.
186 Relationship between the Transmural Dispersion of Repolarization and Left Atrial Pressure during Diuresis in a Volume Overloaded State RamaDilip Gajulapalli, Mohamed Alalwani, Deepak Pattanshetty, Wilson Tang; Cleveland Clinic, Cleveland, Ohio Background: Ventricular volume overload causing mechanical wall stress has been suspected of causing exaggeration of transmural dispersion of repolarization. We hypothesized that the T peak to T end interval (Tpe) as measured on the surface electrocardiogram (EKG) and presumed to be the surrogate of transmural dispersion of repolarization is related to measurements by the Swan Ganz (SG) pulmonary artery (PA) catheter indicating the volume status in patients admitted to hospital for presumed acute decompensated heart failure. Methods: Retrospective review of patient records admitted to the heart failure unit at our institution in 2015 for goal directed therapy using Swan Ganz monitoring as well as having a documented EKG at admission and discharge or follow up when they were deemed euvolemic. After de identification and blinding, the Tpe interval as defined by the standard tangent method was measured using electronic calipers. Admission Tpe measurements were then compared to those at discharge or follow up. All clinical characteristics including SG measurements during their treatment are documented for comparison. Results: In a total of 100 subjects, the mean Tpe (milliseconds) during volume overloaded state was 2.43 compared to 2.01 post diuresis or at follow up (P < .001). The mean pulmonary capillary wedge pressure (PCWP) during volume overloaded state was 29.84 mmHg compared to 16.75 mmHg post diuresis (P < .001). There seemed to be a positive trend between the change in Tpe and simultaneous reduction in PCWP (r = 0.16), however the correlation seemed stronger in those patients whose Tpe improved better than the median (r = 0.25) than those who did not improve at all or improved less than the median (r = 0.13). Patients who were paced seemed to have a weaker correlation (r = 0.02) than non-paced subjects (r = 0.21). Patients without a pacer and whose Tpe improved more than the median had the best correlation (r = 0.40) Conclusions: Subjects whose Tpe improved better than median seem to have better correlation between Tpe and PA pressures than those whose Tpe improved marginally or not at all. Non Paced subjects correlated better that paced subjects. Tpe may have a potential in the prediction of volume overloaded state in heart failure patients.
Fig. 1. A. Association of OI threshold crossing of 60 ohm-days with Ventricular Tachyarrhythmias (VT/VF). B. Association of OI threshold crossing of 60 ohm-days with Atrial Tachyarrhythmias (AT/AF).