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179 Does Pump Speed Determine Exercise Capacity in Patients Receiving Continuous Flow Support with HMII Device?
S66
The Journal of Heart and Lung Transplantation, Vol 30, No 4S, April 2011
Minneapolis, MN; 2Emergency Medicine, Abbott North Western Hospital, Minneapolis, MN. Purpose: Increasing use of second and third generation ventricular assist devices (LVADS), as well as improved survival of patients with these pumps will mean a larger number of patients with VADs in the community. This will necessitate an increasing need for well-trained and knowledgeable emergency medical services technicians (EMST). The aim of the study was to evaluate the level of knowledge and formal education amongst EMS technicians and their preparedness to respond appropriately when a clinical situation with a patient with a LVAD arises in the field. Methods and Materials: We conducted an anonymous web based survey amongst EMST in one mid-western state. The survey consisted, of seven questions to assess EMSTs’ ability to respond to an unstable patient with a VAD in the community. Electronically generated responses were collected and analyzed. Results: Total of 299 EMST responded to the survey, 67.9% from small communities with population of less than 50,000 and 32.1% from large communities with population of ⬎ 50,000. Hundred and seventeen responders (40.8%) never heard the term LVAD, 246 (86%) never took care of a patient with LVAD, 209 (81.6%) were able to identify the main indication of mechanical circulatory support. The presence of pulse and measurable blood pressure were perceived as the most useful initial assessment (47% and 52.9% of responders respectively). In a setting of cardiac arrest 50.4% of responders answered that chest compression is indicated. Finally, 199 (83.3%) EMST admitted to not having any type of training in the care of patients with LVADs. Conclusions: There appears to be a significant unmet need for formal training of EMTS in the emergency management of patients with LVADs. National guidelines and structured educational programs should be developed to provide adequate emergency care training, increase awareness and improve responses to ill patients with LVADs once they are discharged back to their home communities. 178 Risk of Bleeding and Stroke in 700 HeartMate II LVAD Outpatients S.D. Russell,1 A. Boyle,2 B. Sun,3 U. Jorde,4 S.J. Park,5 O.H. Frazier,6 K.S. Sundareswaran,7 D. Farrar,7 C.A. Milano.8 1Medicine/Cardiology, Johns Hopkins Hospital, Baltimore, MD; 2Medicine, Aurora St. Lukes Medical Center, Milwaukee, WI; 3Surgery, Ohio State University, Columbus, OH; 4Medicine, Columbia University School of Medicine, New York, NY; 5Surgery, Mayo Clinic, Rochester, MN; 6Surgery, Texas Heart Institute, Houston, TX; 7Thoratec Corporation, Pleasanton, CA; 8 Surgery, Duke University Medical Center, Durham, NC. Purpose: Bleeding is the most frequent adverse event in patients (pts) with left ventricular assist devices (LVAD), and stroke is one of the most serious. We sought to determine pre- and post-operative risk factors for late bleeding and stroke in HeartMate II (HMII) LVAD pts. Methods and Materials: Advanced heart failure pts (n⫽701) discharged from the hospital in the HMII bridge to transplant (n⫽395) and destination therapy (n⫽306) clinical trials were evaluated. Average age was 56 ⫾ 14 yrs, 51% had ischemic etiology, 12% prior stroke, 85% on inotropic support, and LV ejection fraction was 17 ⫾ 6%. Mean LVAD support duration was 1.3 ⫾ 1.2 yrs (longest: 5.2 yr). Bleeding (BL) requiring transfusion of ⬎ 2 U/24 hours or surgery, stroke [hemorrhagic (HS) and ischemic (IS)], and pump thrombosis (PT) requiring clinical intervention were tracked from hospital discharge until pt outcome. Statistical analysis was performed using Cox Proportional Hazard Models. Results: Older age, lower preoperative serum albumin, ischemic etiology, and female sex were statistically significant multivariate predictors of BL. The main sites of bleeding included gastrointestinal (38% of events), wound (13%), epistaxis (5%), and anemia (19%). Females had over twice the event rates vs males of HS, IS, and PT. Bleeding events occurred over all INR ranges, but 31% of events occurred with INRs ⬎ 2.5 and over 38% (12/32) of IS occurred at INR⬍1.5. 34% of pts with IS, 20% with HS, and 38% with PT had an infection within 2 weeks of the event.
Table Preop factor
Bleeding1 H.R.2
Isc. stroke1 H.R.2
Hem. stroke1 H.R.2
Sex M
0.60
1.54 [1.16, 2.04]** 0.02
F
0.97
0.05
2.57 [1.28, 5.13]**
2.18 [1.25, 3.81]**
ns
ns
ns
ns
Age ⬍⫽65
0.63
⬎65
0.85
0.03
⬍⫽3.3
0.80
1.41 [1.10, 1.82]** 0.03
⬎3.3
0.65
0.04
1.35 [1.03, 1.77]*
0.03
Serum albumin
1
*
Events/Patient-Year; 2Hazard Ratio from multivariate Cox Model; p ⬍ 0.05; **p⬍ 0.01
Conclusions: Bleeding is higher in older pts, and hemorrhagic and ischemic strokes are higher in females and those with active infections, suggesting anticoagulation should be appropriately tailored to these groups. 179 Does Pump Speed Determine Exercise Capacity in Patients Receiving Continuous Flow Support with HMII Device? M. Noor,1,2 C. Bowles,1,2 C. Webb,1 S. Rahman Haley,1 N.R. Banner.1,2 1 Department of Cardiopulmonary Transplantation, Royal Brompton and Harefield NHS Foundation Trust, Harefield Hospital, Harefield, Middlesex, United Kingdom; 2Imperial College London, London, United Kingdom. Purpose: Patients receiving support with Thoratec HeartMate II devices are normally maintained with fixed pump speed. Recently some manufacturers have sort to develop algorithms to increase pump speed and flow during exercise. It is uncertain whether this would have a significant effect on exercise capacity since pump flow is determined by preload on the pump (residual LV function) and afterload (influenced by vasodilatation in exercising muscle). Methods and Materials: We exercised 30 patients at 6 months post HMII implantation, using a modified Bruce protocol at the lowest pump speed available (approx 6000 rpm) and again at usual speed (approx 9000 rpm). To analyse the interaction between residual LV function, pump speed and exercise capacity we divided the patients in two groups; group A (n ⫽ 19) patients had improved ejection fraction (ⱖ 40%) at the time of testing and group B (n ⫽ 11) had reduced ejection fraction (⬍ 40%). Results: In group A, at 6000 rpm the peak VO2 was 20.8 ⫾ 5.5 ml/kg per min, rising to 21.4 ⫾ 4.8 ml/kg per min (p⫽0.38) with increased pump speed at 9000 rpm. In group B the peak VO2 was lower for both speeds; 14.7 ⫾ 5.9 (p⫽ 0.03 versus group A) and 17.2 ⫾ 5.3 (p⫽ 0.09 versus group A) respectively. However, in group B the peak VO2 increased significantly by 2.5 ml/kg per min (p⫽0.02) when the pump speed was increased. Conclusions: HMII patients with poor residual LV function have a lower peak VO2 and are more sensitive to pump speed than patients with improved LV function. This suggests that if a speed adjustment algorithm were to be used, it is likely to be of most benefit to patients with a poor residual LV function. 180 Gastrointestinal Bleeding (GIB) with Left Ventricular Assist Devices (LVADs): Risk Factors, Etiology and Outcomes S. Sharma,1 V. Kushnir,2 C.P. Gyawali,2 G.A. Ewald,1 J. Seccombe,3 E. Novak,1 I.-W. Wang,4 S. Joseph.1 1Division of Cardiovascular Disease, Washington University School of Medicine, Saint Louis, MO; 2 Division of Gastroenterology, Washington University School of Medicine, Saint Louis, MO; 3Internal Medicine, Washington University School of Medicine, Saint Louis, MO; 4Division of Cardiothoracic Surgery, Washington University School of Medicine, Saint Louis, MO. Purpose: High rates of GIB are described with LVADs but etiology remains unclear. We reviewed presentations and outcomes to assess mechanisms of GIB. Methods and Materials: Clinical records of 154 pts (55.4 yr, 122 M/32F) with continuous flow HM II (n⫽112) and pulsatile flow HM XVE (n⫽42) LVADs implanted were retrospectively interrogated. Overt or occult GIB
The Journal of Heart and Lung Transplantation, Vol 30, No 4S, April 2011
Minneapolis, MN; 2Emergency Medicine, Abbott North Western Hospital, Minneapolis, MN. Purpose: Increasing use of second and third generation ventricular assist devices (LVADS), as well as improved survival of patients with these pumps will mean a larger number of patients with VADs in the community. This will necessitate an increasing need for well-trained and knowledgeable emergency medical services technicians (EMST). The aim of the study was to evaluate the level of knowledge and formal education amongst EMS technicians and their preparedness to respond appropriately when a clinical situation with a patient with a LVAD arises in the field. Methods and Materials: We conducted an anonymous web based survey amongst EMST in one mid-western state. The survey consisted, of seven questions to assess EMSTs’ ability to respond to an unstable patient with a VAD in the community. Electronically generated responses were collected and analyzed. Results: Total of 299 EMST responded to the survey, 67.9% from small communities with population of less than 50,000 and 32.1% from large communities with population of ⬎ 50,000. Hundred and seventeen responders (40.8%) never heard the term LVAD, 246 (86%) never took care of a patient with LVAD, 209 (81.6%) were able to identify the main indication of mechanical circulatory support. The presence of pulse and measurable blood pressure were perceived as the most useful initial assessment (47% and 52.9% of responders respectively). In a setting of cardiac arrest 50.4% of responders answered that chest compression is indicated. Finally, 199 (83.3%) EMST admitted to not having any type of training in the care of patients with LVADs. Conclusions: There appears to be a significant unmet need for formal training of EMTS in the emergency management of patients with LVADs. National guidelines and structured educational programs should be developed to provide adequate emergency care training, increase awareness and improve responses to ill patients with LVADs once they are discharged back to their home communities. 178 Risk of Bleeding and Stroke in 700 HeartMate II LVAD Outpatients S.D. Russell,1 A. Boyle,2 B. Sun,3 U. Jorde,4 S.J. Park,5 O.H. Frazier,6 K.S. Sundareswaran,7 D. Farrar,7 C.A. Milano.8 1Medicine/Cardiology, Johns Hopkins Hospital, Baltimore, MD; 2Medicine, Aurora St. Lukes Medical Center, Milwaukee, WI; 3Surgery, Ohio State University, Columbus, OH; 4Medicine, Columbia University School of Medicine, New York, NY; 5Surgery, Mayo Clinic, Rochester, MN; 6Surgery, Texas Heart Institute, Houston, TX; 7Thoratec Corporation, Pleasanton, CA; 8 Surgery, Duke University Medical Center, Durham, NC. Purpose: Bleeding is the most frequent adverse event in patients (pts) with left ventricular assist devices (LVAD), and stroke is one of the most serious. We sought to determine pre- and post-operative risk factors for late bleeding and stroke in HeartMate II (HMII) LVAD pts. Methods and Materials: Advanced heart failure pts (n⫽701) discharged from the hospital in the HMII bridge to transplant (n⫽395) and destination therapy (n⫽306) clinical trials were evaluated. Average age was 56 ⫾ 14 yrs, 51% had ischemic etiology, 12% prior stroke, 85% on inotropic support, and LV ejection fraction was 17 ⫾ 6%. Mean LVAD support duration was 1.3 ⫾ 1.2 yrs (longest: 5.2 yr). Bleeding (BL) requiring transfusion of ⬎ 2 U/24 hours or surgery, stroke [hemorrhagic (HS) and ischemic (IS)], and pump thrombosis (PT) requiring clinical intervention were tracked from hospital discharge until pt outcome. Statistical analysis was performed using Cox Proportional Hazard Models. Results: Older age, lower preoperative serum albumin, ischemic etiology, and female sex were statistically significant multivariate predictors of BL. The main sites of bleeding included gastrointestinal (38% of events), wound (13%), epistaxis (5%), and anemia (19%). Females had over twice the event rates vs males of HS, IS, and PT. Bleeding events occurred over all INR ranges, but 31% of events occurred with INRs ⬎ 2.5 and over 38% (12/32) of IS occurred at INR⬍1.5. 34% of pts with IS, 20% with HS, and 38% with PT had an infection within 2 weeks of the event.
Table Preop factor
Bleeding1 H.R.2
Isc. stroke1 H.R.2
Hem. stroke1 H.R.2
Sex M
0.60
1.54 [1.16, 2.04]** 0.02
F
0.97
0.05
2.57 [1.28, 5.13]**
2.18 [1.25, 3.81]**
ns
ns
ns
ns
Age ⬍⫽65
0.63
⬎65
0.85
0.03
⬍⫽3.3
0.80
1.41 [1.10, 1.82]** 0.03
⬎3.3
0.65
0.04
1.35 [1.03, 1.77]*
0.03
Serum albumin
1
*
Events/Patient-Year; 2Hazard Ratio from multivariate Cox Model; p ⬍ 0.05; **p⬍ 0.01
Conclusions: Bleeding is higher in older pts, and hemorrhagic and ischemic strokes are higher in females and those with active infections, suggesting anticoagulation should be appropriately tailored to these groups. 179 Does Pump Speed Determine Exercise Capacity in Patients Receiving Continuous Flow Support with HMII Device? M. Noor,1,2 C. Bowles,1,2 C. Webb,1 S. Rahman Haley,1 N.R. Banner.1,2 1 Department of Cardiopulmonary Transplantation, Royal Brompton and Harefield NHS Foundation Trust, Harefield Hospital, Harefield, Middlesex, United Kingdom; 2Imperial College London, London, United Kingdom. Purpose: Patients receiving support with Thoratec HeartMate II devices are normally maintained with fixed pump speed. Recently some manufacturers have sort to develop algorithms to increase pump speed and flow during exercise. It is uncertain whether this would have a significant effect on exercise capacity since pump flow is determined by preload on the pump (residual LV function) and afterload (influenced by vasodilatation in exercising muscle). Methods and Materials: We exercised 30 patients at 6 months post HMII implantation, using a modified Bruce protocol at the lowest pump speed available (approx 6000 rpm) and again at usual speed (approx 9000 rpm). To analyse the interaction between residual LV function, pump speed and exercise capacity we divided the patients in two groups; group A (n ⫽ 19) patients had improved ejection fraction (ⱖ 40%) at the time of testing and group B (n ⫽ 11) had reduced ejection fraction (⬍ 40%). Results: In group A, at 6000 rpm the peak VO2 was 20.8 ⫾ 5.5 ml/kg per min, rising to 21.4 ⫾ 4.8 ml/kg per min (p⫽0.38) with increased pump speed at 9000 rpm. In group B the peak VO2 was lower for both speeds; 14.7 ⫾ 5.9 (p⫽ 0.03 versus group A) and 17.2 ⫾ 5.3 (p⫽ 0.09 versus group A) respectively. However, in group B the peak VO2 increased significantly by 2.5 ml/kg per min (p⫽0.02) when the pump speed was increased. Conclusions: HMII patients with poor residual LV function have a lower peak VO2 and are more sensitive to pump speed than patients with improved LV function. This suggests that if a speed adjustment algorithm were to be used, it is likely to be of most benefit to patients with a poor residual LV function. 180 Gastrointestinal Bleeding (GIB) with Left Ventricular Assist Devices (LVADs): Risk Factors, Etiology and Outcomes S. Sharma,1 V. Kushnir,2 C.P. Gyawali,2 G.A. Ewald,1 J. Seccombe,3 E. Novak,1 I.-W. Wang,4 S. Joseph.1 1Division of Cardiovascular Disease, Washington University School of Medicine, Saint Louis, MO; 2 Division of Gastroenterology, Washington University School of Medicine, Saint Louis, MO; 3Internal Medicine, Washington University School of Medicine, Saint Louis, MO; 4Division of Cardiothoracic Surgery, Washington University School of Medicine, Saint Louis, MO. Purpose: High rates of GIB are described with LVADs but etiology remains unclear. We reviewed presentations and outcomes to assess mechanisms of GIB. Methods and Materials: Clinical records of 154 pts (55.4 yr, 122 M/32F) with continuous flow HM II (n⫽112) and pulsatile flow HM XVE (n⫽42) LVADs implanted were retrospectively interrogated. Overt or occult GIB