Firas Zahr - Academia.edu (original) (raw)

Papers by Firas Zahr

Research paper thumbnail of Percutaneous Treatment of Adverse Left Ventricular Remodeling

Catheter Based Valve and Aortic Surgery, 2016

Research paper thumbnail of The clinical picture : A young man with unexplained dyspnea

Cleveland Clinic Journal of Medicine, 2006

Research paper thumbnail of Giant saphenous vein graft pseudoaneurysm to right posterior descending artery presenting with superior vena cava syndrome

World journal of cardiology, Jan 26, 2015

Saphenous vein grafts (SVG) pseudoaneurysms, especially giant ones, are rare and occur as a late ... more Saphenous vein grafts (SVG) pseudoaneurysms, especially giant ones, are rare and occur as a late complication of coronary artery bypass grafting. This condition affects both genders and typically occurs within the sixth decade of life. The clinical presentation ranges from an asymptomatic incidental finding on imaging studies to new onset angina, dyspnea, myocardial infarction or symptoms related to compression of neighboring structures. An 82-year-old woman presented with acute onset back pain, dyspnea and was noted to have significantly engorged neck veins. In the emergency department, a chest computed tomographic angiogram with intravenous contrast revealed a ruptured giant bilobed SVG pseudoaneurysm to the right posterior descending artery (RPDA). This imaging modality also demonstrated compression of the superior vena cava (SVC) by the SVG pseudoaneurysm. Coronary angiogram with bypass study was performed to establish the patency of this graft. Endovascular coiling and emboliza...

Research paper thumbnail of A young man with unexplained dyspnea

Cleveland Clinic Journal of Medicine, 2006

22-YEAR-OLD MAN presents to the pul-monary clinic with persistent dyspnea with exertion, nasal co... more 22-YEAR-OLD MAN presents to the pul-monary clinic with persistent dyspnea with exertion, nasal congestion, and epistaxis. About a year ago, the patient was evalu-ated for the same symptoms at a community hospital. At the time, computed tomography (CT) of the chest revealed ...

Research paper thumbnail of Late Bacterial Endocarditis of an Amplatzer Atrial Septal Defect Occluder Device

The American Journal of Cardiology, 2010

A 66-year-old man with a large secundum atrial septal defect (ASD) that had been repaired percuta... more A 66-year-old man with a large secundum atrial septal defect (ASD) that had been repaired percutaneously 30 months previously with an Amplatzer ASD occluder (ASO) presented with fevers and Staphylococcus aureus bacteremia. Transesophageal echocardiography revealed a 1.5 x 1.5 cm mobile mass on the left atrial side of his ASO consistent with a vegetation. When the ASO was explanted, the left atrial side of the device was poorly endothelialized. In conclusion, the present report is the first description of late infective endocarditis in an adult with an ASO.

Research paper thumbnail of Ventral cardiac denervation increased right coronary arterial blood flow

International Journal of Cardiology, Jan 18, 2007

Background: Cardiac denervation accompanied with coronary artery bypass surgery has been widely p... more Background: Cardiac denervation accompanied with coronary artery bypass surgery has been widely performed for the treatment of vasospastic angina associated with atherosclerotic coronary artery disease. However, the effect of cardiac denervation on phasic coronary blood flow patterns of the left anterior descending coronary artery (LAD), left circumflex coronary artery (LCX) and right coronary artery (RCA) remains unknown. This study aimed to investigate the effect of cardiac denervation on phasic coronary blood flow patterns of the LAD, LCX and RCA. Methods: Phasic coronary blood flow patterns were analyzed using three flow probes placed around the LAD, LCX and RCA with and without LAD stenosis. Ventral cardiac denervation (VCD) was performed in 8 pigs, and 16 pigs were used as control subjects. Autonomic activities before and after the VCD were quantified by wavelet analysis of heart rate variability. Results: The mean LAD flow (34.4 T 9.4 to 32.6 T 7.1 ml/min, p = 0.638) and mean LCX flow (26.3 T 10.2 to 27.2 T 6.0 ml/min, p = 0.825) showed no significant change after VCD, while the mean RCA flow (31.3 T 9.0 to 38.2 T 11.2 ml/min, p = 0.003) significantly increased. The hemodynamic variables in the VCD group were well maintained after creation of LAD stenosis, while they deteriorated in the control group. The low-frequency components, high-frequency components and their ratio did not change after VCD. Conclusions: VCD prevented the deterioration of cardiac function after creation of an LAD stenosis and resulted in an increase of the mean RCA flow. VCD did not affect autonomic nervous system activity. D

Research paper thumbnail of Abstract 16050: Regional System to Optimize Door-to-Balloon Times in Patients Transferred for Primary Percutaneous Coronary Intervention

Circulation, Nov 20, 2012

Research paper thumbnail of Development of a Samll, Implantable Right Ventricular Assist Device

Research paper thumbnail of Preoperative Risk Factors for Mortality after Biventricular Assist Device Implantation

J Card Fail, 2007

A right ventricular assist device is a treatment option for patients with severe right ventricula... more A right ventricular assist device is a treatment option for patients with severe right ventricular failure after left ventricular assist device (LVAD) implantation. Recognition of risk factors for mortality after biventricular assist device (BiVAD) implantation is important for patient selection and optimal outcomes. We reviewed our experiences between 1991 and 2005 in 44 patients who were supported by both an LVAD and a right ventricular assist device. Thirteen patients (30%) survived until heart transplantation, and 31 patients (70%) died while on support. The multivariate analysis shows that post-LVAD extracorporeal membrane oxygenation and worsening renal function are associated with the highest postoperative mortality. The univariate analysis also included previous thoracic surgery and ischemic cardiomyopathy as potential preoperative indicators for poor outcome after BiVAD implants. No differences were observed in the rates for the need of preoperative support with a ventilator, an intra-aortic balloon pump, or extracorporeal membrane oxygenation, or in the rates of postoperative complications between survivors and nonsurvivors. BiVAD implantation remains one of the challenges in treating severe heart failure. Previous cardiac surgery, elevated creatinine, and post-LVAD extracorporeal membrane oxygenation were risk factors for mortality after BiVAD implantation. Dialated Cardiomyopathy on the other hand was associated with a more favorable outcome.

Research paper thumbnail of Impact of left atrial appendage exclusion on left atrial function

Objectives: We sought to investigate the short-term and midterm effects of left atrial appendage ... more Objectives: We sought to investigate the short-term and midterm effects of left atrial appendage exclusion on left atrial function. Left atrial appendage exclusion is considered a possible therapeutic option for stroke prevention in patients with atrial fibrillation. Favorable outcomes have encouraged widespread use of left atrial appendage exclusion for cardiac surgical patients-even for patients in sinus rhythm who have stroke risk factors; however, the chronic effects on left atrial function of left atrial appendage exclusion are unclear.

Research paper thumbnail of Abstract 2549: Impact of Left Atrial Appendage Exclusion on Left Atrial Function

Circulation, Oct 31, 2006

Research paper thumbnail of Trends in hospitalization for takotsubo cardiomyopathy in the United States

American Heart Journal, 2016

Takotsubo (or stress induced) cardiomyopathy is characterized by transient left ventricular systo... more Takotsubo (or stress induced) cardiomyopathy is characterized by transient left ventricular systolic dysfunction. Recent trends in patient volume, characteristics, and outcomes in the United States are unknown. Using 2007-2012 National Inpatient Sample data, we identified 22,005 adults (≥18 years) with a primary and 31,942 adults with a secondary discharge diagnosis of takotsubo cardiomyopathy (International Classification of Diseases, Ninth Revision, code 429.83) who underwent diagnostic coronary angiography. During 2007 to 2012, the incidence of takotsubo cardiomyopathy increased over 3-fold: 52/million discharges in 2007 to 178/million in 2012 (P < .001). We found a temporal increase in the prevalence of cardiac arrest, cardiogenic shock, cardiovascular risk factors (diabetes, hypertension), and psychiatric disorders (P trend < .0001 for all). In-hospital mortality was 1.1% and remained unchanged over this period (P = .22). Compared to the primary diagnosis group, mortality in the secondary diagnosis group was higher (1.1% vs 3.2%) and was associated with higher incidence of cardiogenic shock, cardiac arrest, and respiratory failure. Men represent 8% of patients in the primary diagnosis group and 12% in the secondary group. In both groups, men had a higher incidence of shock, cardiac arrest, and respiratory failure. Although their mortality was higher than women in the primary group (3.0% vs 0.9%, adjusted odds ratio 3.85, 1.74-8.51), it was comparable in the secondary group (4.8% vs 3.0%). We found a marked increase in the hospitalization for takotsubo cardiomyopathy in the United States in recent years, suggesting higher incidence than prior reports. Although outcomes have remained favorable, there is an increasing burden of cardiovascular and psychiatric disorders in this population with growing cost of care. Risk of mortality is higher in men and in patients with underlying critical illness. The excess mortality in these groups appears to be mediated by greater severity of disease.

Research paper thumbnail of Trends in Hospitalization for Takotsubo Cardiomyopathy in the United States, 2007-2012

Journal of the American College of Cardiology, 2015

Background: Takotsubo cardiomyopathy (TCMP) is a stress-induced left ventricular systolic dysfunc... more Background: Takotsubo cardiomyopathy (TCMP) is a stress-induced left ventricular systolic dysfunction that is usually reversible and is more common in women. Contemporary trends in hospitalization due to TCMP in the U.S. as well as predictors of in-hospital mortality are unknown.

Research paper thumbnail of Phasic coronary blood flow patterns in dogs vs. pigs: an acute ischemic heart study

Medical science monitor : international medical journal of experimental and clinical research, 2008

Canine and porcine hearts have been widely used to investigate diagnoses, interventions, and surg... more Canine and porcine hearts have been widely used to investigate diagnoses, interventions, and surgical therapies for ischemic heart disease. Dogs and pigs are known to vary with regard to the anatomic distribution of their coronary arteries. However, the mechanisms of these differences and the differing phasic coronary blood flow patterns between the two species are not well characterized. Phasic coronary blood flow patterns and hemodynamic data were analyzed using three flow probes placed around the left anterior descending (LAD), left circumflex (LCX), and right coronary (RCA) arteries in both canine and porcine models. Systolic left ventricular pressure, arterial pressure, and systemic vascular resistance in dogs were higher than in pigs. Likewise, total coronary blood flow, LAD flow, and LCX flow were higher in dogs than in pigs. LCX flow was higher in dogs, but RCA flow was higher in pigs. Diastolic fraction and diastolic/systolic peak velocity ratio of the LAD, LCX, and RCA sho...

Research paper thumbnail of Endoscopic Management of Biliary Complications After Liver Transplantation

Therapeutic Gastrointestinal Endoscopy, 2011

Research paper thumbnail of Impact of left atrial appendage exclusion on left atrial function

The Journal of Thoracic and Cardiovascular Surgery, 2007

Objectives: We sought to investigate the short-term and midterm effects of left atrial appendage ... more Objectives: We sought to investigate the short-term and midterm effects of left atrial appendage exclusion on left atrial function. Left atrial appendage exclusion is considered a possible therapeutic option for stroke prevention in patients with atrial fibrillation. Favorable outcomes have encouraged widespread use of left atrial appendage exclusion for cardiac surgical patients-even for patients in sinus rhythm who have stroke risk factors; however, the chronic effects on left atrial function of left atrial appendage exclusion are unclear.

Research paper thumbnail of A novel device for left atrial appendage exclusion: The third-generation atrial exclusion device

The Journal of Thoracic and Cardiovascular Surgery, 2008

Objective: Occlusion of the left atrial appendage is proposed to reduce the risk of stroke in pat... more Objective: Occlusion of the left atrial appendage is proposed to reduce the risk of stroke in patients with atrial fibrillation. The third-generation atrial exclusion device, modified to provide uniform distribution of pressure at appendage exclusion, was assessed for safety and effectiveness in a canine model and compared with a surgical stapler.

Research paper thumbnail of TCT-824 The impact of creation of a transcatheter aortic valve program on surgical aortic valve replacement (sAVR) volume and outcomes: A single center experience

Journal of the American College of Cardiology, 2012

Research paper thumbnail of Platelet Reactivity Testing Following Coronary Percutaneous Intervention is Independent of the Initial Clinical Presentation

Journal of the American College of Cardiology, 2010

Background: Patients undergoing percutaneous coronary interventions (PCI) have been shown to be a... more Background: Patients undergoing percutaneous coronary interventions (PCI) have been shown to be at risk for recurrent events if they are low responders to clopidogrel. However, whether the increased platelet reactivity accompanying an acute coronary syndrome (ACS) is a cause for low response to clopidogrel is unknown. Accordingly, we investigated the impact of clinical presentation (ACS vs. Stable Angina, SA) on platelet reactivity and clopidogrel response in patients undergoing PCI.

Research paper thumbnail of Preoperative Risk Factors for Mortality after Biventricular Assist Device Implantation

Journal of Cardiac Failure, 2007

A right ventricular assist device is a treatment option for patients with severe right ventricula... more A right ventricular assist device is a treatment option for patients with severe right ventricular failure after left ventricular assist device (LVAD) implantation. Recognition of risk factors for mortality after biventricular assist device (BiVAD) implantation is important for patient selection and optimal outcomes. We reviewed our experiences between 1991 and 2005 in 44 patients who were supported by both an LVAD and a right ventricular assist device. Thirteen patients (30%) survived until heart transplantation, and 31 patients (70%) died while on support. The multivariate analysis shows that post-LVAD extracorporeal membrane oxygenation and worsening renal function are associated with the highest postoperative mortality. The univariate analysis also included previous thoracic surgery and ischemic cardiomyopathy as potential preoperative indicators for poor outcome after BiVAD implants. No differences were observed in the rates for the need of preoperative support with a ventilator, an intra-aortic balloon pump, or extracorporeal membrane oxygenation, or in the rates of postoperative complications between survivors and nonsurvivors. BiVAD implantation remains one of the challenges in treating severe heart failure. Previous cardiac surgery, elevated creatinine, and post-LVAD extracorporeal membrane oxygenation were risk factors for mortality after BiVAD implantation. Dialated Cardiomyopathy on the other hand was associated with a more favorable outcome.

Research paper thumbnail of Percutaneous Treatment of Adverse Left Ventricular Remodeling

Catheter Based Valve and Aortic Surgery, 2016

Research paper thumbnail of The clinical picture : A young man with unexplained dyspnea

Cleveland Clinic Journal of Medicine, 2006

Research paper thumbnail of Giant saphenous vein graft pseudoaneurysm to right posterior descending artery presenting with superior vena cava syndrome

World journal of cardiology, Jan 26, 2015

Saphenous vein grafts (SVG) pseudoaneurysms, especially giant ones, are rare and occur as a late ... more Saphenous vein grafts (SVG) pseudoaneurysms, especially giant ones, are rare and occur as a late complication of coronary artery bypass grafting. This condition affects both genders and typically occurs within the sixth decade of life. The clinical presentation ranges from an asymptomatic incidental finding on imaging studies to new onset angina, dyspnea, myocardial infarction or symptoms related to compression of neighboring structures. An 82-year-old woman presented with acute onset back pain, dyspnea and was noted to have significantly engorged neck veins. In the emergency department, a chest computed tomographic angiogram with intravenous contrast revealed a ruptured giant bilobed SVG pseudoaneurysm to the right posterior descending artery (RPDA). This imaging modality also demonstrated compression of the superior vena cava (SVC) by the SVG pseudoaneurysm. Coronary angiogram with bypass study was performed to establish the patency of this graft. Endovascular coiling and emboliza...

Research paper thumbnail of A young man with unexplained dyspnea

Cleveland Clinic Journal of Medicine, 2006

22-YEAR-OLD MAN presents to the pul-monary clinic with persistent dyspnea with exertion, nasal co... more 22-YEAR-OLD MAN presents to the pul-monary clinic with persistent dyspnea with exertion, nasal congestion, and epistaxis. About a year ago, the patient was evalu-ated for the same symptoms at a community hospital. At the time, computed tomography (CT) of the chest revealed ...

Research paper thumbnail of Late Bacterial Endocarditis of an Amplatzer Atrial Septal Defect Occluder Device

The American Journal of Cardiology, 2010

A 66-year-old man with a large secundum atrial septal defect (ASD) that had been repaired percuta... more A 66-year-old man with a large secundum atrial septal defect (ASD) that had been repaired percutaneously 30 months previously with an Amplatzer ASD occluder (ASO) presented with fevers and Staphylococcus aureus bacteremia. Transesophageal echocardiography revealed a 1.5 x 1.5 cm mobile mass on the left atrial side of his ASO consistent with a vegetation. When the ASO was explanted, the left atrial side of the device was poorly endothelialized. In conclusion, the present report is the first description of late infective endocarditis in an adult with an ASO.

Research paper thumbnail of Ventral cardiac denervation increased right coronary arterial blood flow

International Journal of Cardiology, Jan 18, 2007

Background: Cardiac denervation accompanied with coronary artery bypass surgery has been widely p... more Background: Cardiac denervation accompanied with coronary artery bypass surgery has been widely performed for the treatment of vasospastic angina associated with atherosclerotic coronary artery disease. However, the effect of cardiac denervation on phasic coronary blood flow patterns of the left anterior descending coronary artery (LAD), left circumflex coronary artery (LCX) and right coronary artery (RCA) remains unknown. This study aimed to investigate the effect of cardiac denervation on phasic coronary blood flow patterns of the LAD, LCX and RCA. Methods: Phasic coronary blood flow patterns were analyzed using three flow probes placed around the LAD, LCX and RCA with and without LAD stenosis. Ventral cardiac denervation (VCD) was performed in 8 pigs, and 16 pigs were used as control subjects. Autonomic activities before and after the VCD were quantified by wavelet analysis of heart rate variability. Results: The mean LAD flow (34.4 T 9.4 to 32.6 T 7.1 ml/min, p = 0.638) and mean LCX flow (26.3 T 10.2 to 27.2 T 6.0 ml/min, p = 0.825) showed no significant change after VCD, while the mean RCA flow (31.3 T 9.0 to 38.2 T 11.2 ml/min, p = 0.003) significantly increased. The hemodynamic variables in the VCD group were well maintained after creation of LAD stenosis, while they deteriorated in the control group. The low-frequency components, high-frequency components and their ratio did not change after VCD. Conclusions: VCD prevented the deterioration of cardiac function after creation of an LAD stenosis and resulted in an increase of the mean RCA flow. VCD did not affect autonomic nervous system activity. D

Research paper thumbnail of Abstract 16050: Regional System to Optimize Door-to-Balloon Times in Patients Transferred for Primary Percutaneous Coronary Intervention

Circulation, Nov 20, 2012

Research paper thumbnail of Development of a Samll, Implantable Right Ventricular Assist Device

Research paper thumbnail of Preoperative Risk Factors for Mortality after Biventricular Assist Device Implantation

J Card Fail, 2007

A right ventricular assist device is a treatment option for patients with severe right ventricula... more A right ventricular assist device is a treatment option for patients with severe right ventricular failure after left ventricular assist device (LVAD) implantation. Recognition of risk factors for mortality after biventricular assist device (BiVAD) implantation is important for patient selection and optimal outcomes. We reviewed our experiences between 1991 and 2005 in 44 patients who were supported by both an LVAD and a right ventricular assist device. Thirteen patients (30%) survived until heart transplantation, and 31 patients (70%) died while on support. The multivariate analysis shows that post-LVAD extracorporeal membrane oxygenation and worsening renal function are associated with the highest postoperative mortality. The univariate analysis also included previous thoracic surgery and ischemic cardiomyopathy as potential preoperative indicators for poor outcome after BiVAD implants. No differences were observed in the rates for the need of preoperative support with a ventilator, an intra-aortic balloon pump, or extracorporeal membrane oxygenation, or in the rates of postoperative complications between survivors and nonsurvivors. BiVAD implantation remains one of the challenges in treating severe heart failure. Previous cardiac surgery, elevated creatinine, and post-LVAD extracorporeal membrane oxygenation were risk factors for mortality after BiVAD implantation. Dialated Cardiomyopathy on the other hand was associated with a more favorable outcome.

Research paper thumbnail of Impact of left atrial appendage exclusion on left atrial function

Objectives: We sought to investigate the short-term and midterm effects of left atrial appendage ... more Objectives: We sought to investigate the short-term and midterm effects of left atrial appendage exclusion on left atrial function. Left atrial appendage exclusion is considered a possible therapeutic option for stroke prevention in patients with atrial fibrillation. Favorable outcomes have encouraged widespread use of left atrial appendage exclusion for cardiac surgical patients-even for patients in sinus rhythm who have stroke risk factors; however, the chronic effects on left atrial function of left atrial appendage exclusion are unclear.

Research paper thumbnail of Abstract 2549: Impact of Left Atrial Appendage Exclusion on Left Atrial Function

Circulation, Oct 31, 2006

Research paper thumbnail of Trends in hospitalization for takotsubo cardiomyopathy in the United States

American Heart Journal, 2016

Takotsubo (or stress induced) cardiomyopathy is characterized by transient left ventricular systo... more Takotsubo (or stress induced) cardiomyopathy is characterized by transient left ventricular systolic dysfunction. Recent trends in patient volume, characteristics, and outcomes in the United States are unknown. Using 2007-2012 National Inpatient Sample data, we identified 22,005 adults (≥18 years) with a primary and 31,942 adults with a secondary discharge diagnosis of takotsubo cardiomyopathy (International Classification of Diseases, Ninth Revision, code 429.83) who underwent diagnostic coronary angiography. During 2007 to 2012, the incidence of takotsubo cardiomyopathy increased over 3-fold: 52/million discharges in 2007 to 178/million in 2012 (P < .001). We found a temporal increase in the prevalence of cardiac arrest, cardiogenic shock, cardiovascular risk factors (diabetes, hypertension), and psychiatric disorders (P trend < .0001 for all). In-hospital mortality was 1.1% and remained unchanged over this period (P = .22). Compared to the primary diagnosis group, mortality in the secondary diagnosis group was higher (1.1% vs 3.2%) and was associated with higher incidence of cardiogenic shock, cardiac arrest, and respiratory failure. Men represent 8% of patients in the primary diagnosis group and 12% in the secondary group. In both groups, men had a higher incidence of shock, cardiac arrest, and respiratory failure. Although their mortality was higher than women in the primary group (3.0% vs 0.9%, adjusted odds ratio 3.85, 1.74-8.51), it was comparable in the secondary group (4.8% vs 3.0%). We found a marked increase in the hospitalization for takotsubo cardiomyopathy in the United States in recent years, suggesting higher incidence than prior reports. Although outcomes have remained favorable, there is an increasing burden of cardiovascular and psychiatric disorders in this population with growing cost of care. Risk of mortality is higher in men and in patients with underlying critical illness. The excess mortality in these groups appears to be mediated by greater severity of disease.

Research paper thumbnail of Trends in Hospitalization for Takotsubo Cardiomyopathy in the United States, 2007-2012

Journal of the American College of Cardiology, 2015

Background: Takotsubo cardiomyopathy (TCMP) is a stress-induced left ventricular systolic dysfunc... more Background: Takotsubo cardiomyopathy (TCMP) is a stress-induced left ventricular systolic dysfunction that is usually reversible and is more common in women. Contemporary trends in hospitalization due to TCMP in the U.S. as well as predictors of in-hospital mortality are unknown.

Research paper thumbnail of Phasic coronary blood flow patterns in dogs vs. pigs: an acute ischemic heart study

Medical science monitor : international medical journal of experimental and clinical research, 2008

Canine and porcine hearts have been widely used to investigate diagnoses, interventions, and surg... more Canine and porcine hearts have been widely used to investigate diagnoses, interventions, and surgical therapies for ischemic heart disease. Dogs and pigs are known to vary with regard to the anatomic distribution of their coronary arteries. However, the mechanisms of these differences and the differing phasic coronary blood flow patterns between the two species are not well characterized. Phasic coronary blood flow patterns and hemodynamic data were analyzed using three flow probes placed around the left anterior descending (LAD), left circumflex (LCX), and right coronary (RCA) arteries in both canine and porcine models. Systolic left ventricular pressure, arterial pressure, and systemic vascular resistance in dogs were higher than in pigs. Likewise, total coronary blood flow, LAD flow, and LCX flow were higher in dogs than in pigs. LCX flow was higher in dogs, but RCA flow was higher in pigs. Diastolic fraction and diastolic/systolic peak velocity ratio of the LAD, LCX, and RCA sho...

Research paper thumbnail of Endoscopic Management of Biliary Complications After Liver Transplantation

Therapeutic Gastrointestinal Endoscopy, 2011

Research paper thumbnail of Impact of left atrial appendage exclusion on left atrial function

The Journal of Thoracic and Cardiovascular Surgery, 2007

Objectives: We sought to investigate the short-term and midterm effects of left atrial appendage ... more Objectives: We sought to investigate the short-term and midterm effects of left atrial appendage exclusion on left atrial function. Left atrial appendage exclusion is considered a possible therapeutic option for stroke prevention in patients with atrial fibrillation. Favorable outcomes have encouraged widespread use of left atrial appendage exclusion for cardiac surgical patients-even for patients in sinus rhythm who have stroke risk factors; however, the chronic effects on left atrial function of left atrial appendage exclusion are unclear.

Research paper thumbnail of A novel device for left atrial appendage exclusion: The third-generation atrial exclusion device

The Journal of Thoracic and Cardiovascular Surgery, 2008

Objective: Occlusion of the left atrial appendage is proposed to reduce the risk of stroke in pat... more Objective: Occlusion of the left atrial appendage is proposed to reduce the risk of stroke in patients with atrial fibrillation. The third-generation atrial exclusion device, modified to provide uniform distribution of pressure at appendage exclusion, was assessed for safety and effectiveness in a canine model and compared with a surgical stapler.

Research paper thumbnail of TCT-824 The impact of creation of a transcatheter aortic valve program on surgical aortic valve replacement (sAVR) volume and outcomes: A single center experience

Journal of the American College of Cardiology, 2012

Research paper thumbnail of Platelet Reactivity Testing Following Coronary Percutaneous Intervention is Independent of the Initial Clinical Presentation

Journal of the American College of Cardiology, 2010

Background: Patients undergoing percutaneous coronary interventions (PCI) have been shown to be a... more Background: Patients undergoing percutaneous coronary interventions (PCI) have been shown to be at risk for recurrent events if they are low responders to clopidogrel. However, whether the increased platelet reactivity accompanying an acute coronary syndrome (ACS) is a cause for low response to clopidogrel is unknown. Accordingly, we investigated the impact of clinical presentation (ACS vs. Stable Angina, SA) on platelet reactivity and clopidogrel response in patients undergoing PCI.

Research paper thumbnail of Preoperative Risk Factors for Mortality after Biventricular Assist Device Implantation

Journal of Cardiac Failure, 2007

A right ventricular assist device is a treatment option for patients with severe right ventricula... more A right ventricular assist device is a treatment option for patients with severe right ventricular failure after left ventricular assist device (LVAD) implantation. Recognition of risk factors for mortality after biventricular assist device (BiVAD) implantation is important for patient selection and optimal outcomes. We reviewed our experiences between 1991 and 2005 in 44 patients who were supported by both an LVAD and a right ventricular assist device. Thirteen patients (30%) survived until heart transplantation, and 31 patients (70%) died while on support. The multivariate analysis shows that post-LVAD extracorporeal membrane oxygenation and worsening renal function are associated with the highest postoperative mortality. The univariate analysis also included previous thoracic surgery and ischemic cardiomyopathy as potential preoperative indicators for poor outcome after BiVAD implants. No differences were observed in the rates for the need of preoperative support with a ventilator, an intra-aortic balloon pump, or extracorporeal membrane oxygenation, or in the rates of postoperative complications between survivors and nonsurvivors. BiVAD implantation remains one of the challenges in treating severe heart failure. Previous cardiac surgery, elevated creatinine, and post-LVAD extracorporeal membrane oxygenation were risk factors for mortality after BiVAD implantation. Dialated Cardiomyopathy on the other hand was associated with a more favorable outcome.