Background: The NHLBI-sponsored TIME Trial of the CCTRN investigated if the timing of stem cell d... more Background: The NHLBI-sponsored TIME Trial of the CCTRN investigated if the timing of stem cell delivery affects recovery of LV function following STEMI. It was a randomized, placebo-controlled trial of 120 patients with anterior STEMI randomized (2:1) to either 150 million autologous bone marrow mononuclear cells (BMCs) or cell-free placebo with intracoronary delivery on Day 3 or Day 7 following reperfusion with PCI in patients with LV dysfunction (LVEF ¬ Methods and Results: 85 patients (BMC=58; Placebo=27) returned for pre-specified 1 and 2-year follow-up MRIs. Data are presented as the aggregate of the Day 3 and Day 7 groups (means). While LVEF and regional wall motion increased in both groups between baseline and 6 months (p Conclusion: A significant reduction in infarct size and LV mass occurs during the initial six months following reperfused STEMI that is unaffected by BMC administration. After two years, the initial improvement in LV function remained stable in both groups ...
Left ventricular electromechanical mapping (EMM) determines myocardial viability on the basis of ... more Left ventricular electromechanical mapping (EMM) determines myocardial viability on the basis of endocardial electrograms. The aim of the present study was to validate EMM in differentiating infarcted myocardium from viable myocardium by histopathological analysis. Sixty days after implanting an ameroid constrictor over the left circumflex artery to create chronic ischemia in 19 pigs, EMM was performed to construct unipolar voltage (UPV), bipolar voltage (BPV) and linear local shortening (LLS) maps. Noninfarcted and infarcted myocardium were identified by histopathology. Threshold determinations comparing noninfarcted tissue with scarred tissue were made by measuring the area under the receiver operating characteristic curves. From the 19 hearts, 149 myocardial segments were divided into noninfarcted myocardium (n=128) and transmural infarct (n=21). UPV, BPV and LLS values (4.7+/-1.2 mV, 2.8+/-2.5 mV and 10.0+/-5.1%, respectively) of infarcted segments were significantly lower than ...
Journal of Cardiovascular Translational Research, 2021
In this study, we created a reproducible myocardial infarction (MI) model in pigs characterized b... more In this study, we created a reproducible myocardial infarction (MI) model in pigs characterized by a low mortality rate and significant changes in left ventricular function. After administering an arrhythmia prevention regimen, we created a 90-min balloon-induced percutaneous MI in 42 pigs below the first diagonal branch (D1) of the left anterior descending artery. Echocardiograms were performed before and 14 days after MI induction. Pigs with a > 30% decrease in left ventricular ejection fraction (LVEF) underwent electrophysiological mapping by the NOGA system. Our mortality rate was 4.8%. The incidence of ventricular fibrillation (VF) was 28.6%; all VF events were successfully resuscitated. At day 14, echocardiography and NOGA mapping confirmed transmural scar. LVEF decreased 41% from baseline. Radial and circumferential strain significantly decreased in the LAD distal to D1, and the LV showed dyssynchrony. An anti-arrhythmia regimen decreased mortality significantly, and our m...
Thrombus formation after stent deployment has been linked to the use of heparin and of antithromb... more Thrombus formation after stent deployment has been linked to the use of heparin and of antithrombotic agents, such as bivalirudin, during percutaneous coronary intervention. Fluoroscopy has been used to identify stent thrombosis, typically after patients become symptomatic. We describe our use of optical coherence tomography to diagnose and evaluate intraprocedural stent thrombosis in a 68-year-old man who was given bivalirudin just before a percutaneous coronary procedure. This imaging method enabled immediate therapeutic intervention.
SENECA (StEm cell iNjECtion in cAncer survivors) is a phase I, randomized, double-blind, placebo-... more SENECA (StEm cell iNjECtion in cAncer survivors) is a phase I, randomized, double-blind, placebo-controlled study to evaluate the safety and feasibility of delivering allogeneic mesenchymal stromal cells (allo-MSCs) transendocardially in subjects with anthracycline-induced cardiomyopathy (AIC). AIC is an incurable and often fatal syndrome, with a prognosis worse than that of ischemic or nonischemic cardiomyopathy. Recently, cell therapy with MSCs has emerged as a promising new approach to repair damaged myocardium. The study population is 36 cancer survivors with a diagnosis of AIC, left ventricular (LV) ejection fraction ≤40%, and symptoms of heart failure (NYHA class II-III) on optimally-tolerated medical therapy. Subjects must be clinically free of cancer for at least two years with a ≤ 30% estimated five-year risk of recurrence. The first six subjects participated in an open-label, lead-in phase and received 100 million allo-MSCs; the remaining 30 will be randomized 1:1 to recei...
Autologous bone marrow (BM) mesenchymal stem cells (MSCs) and c-kit cardiac progenitor cells (CPC... more Autologous bone marrow (BM) mesenchymal stem cells (MSCs) and c-kit cardiac progenitor cells (CPCs) are two promising cell types being evaluated for patients with heart failure (HF) secondary to ischemic cardiomyopathy. No information is available in humans regarding the relative efficacy of MSCs and CPCs and whether their combination is more efficacious than either cell type alone. CONCERT-HF (Combination Of meseNchymal and c-kit Cardiac stEm cells as Regenerative Therapy for Heart Failure) is a Phase II trial aimed at elucidating these issues by assessing the feasibility, safety, and efficacy of transendocardial administration of autologous MSCs and CPCs, alone and in combination, in patients with HF caused by chronic ischemic cardiomyopathy (coronary artery disease and old myocardial infarction). Using a randomized, double-blinded, placebo-controlled, multi-center, multi-treatment, and adaptive design, CONCERT-HF examines whether administration of MSCs alone, CPCs alone, or MSCs ...
Rationale: The TIME trial was the first cell therapy trial sufficiently powered to determine if t... more Rationale: The TIME trial was the first cell therapy trial sufficiently powered to determine if timing of cell delivery following ST-elevation myocardial infarction (STEMI) affects recovery of left ventricular (LV) function. Objective: To report the 2-year clinical and cardiac magnetic resonance imaging (cMRI) results and their modification by microvascular obstruction (MVO). Methods and Results: TIME was a randomized, double-blind, placebo-controlled trial comparing 150 million bone marrow mononuclear cells (BMC) vs. placebo in 120 patients with anterior STEMIs resulting in LV dysfunction. Primary endpoints included changes in global (LV ejection fraction (LVEF)) and regional (infarct and border zone) function. Secondary endpoints included changes in LV volumes, infarct size and major adverse cardiac events. Here, we analyzed the continued trajectory of these measures out to 2 years and the influence of MVO present at baseline on these long-term outcomes. At 2 years (n=85), LVEF wa...
Cancer patients with recently placed drug-eluting stents (DESs) often require premature dual anti... more Cancer patients with recently placed drug-eluting stents (DESs) often require premature dual antiplatelet therapy (DAPT) discontinuation for cancer-related procedures. Optical coherence tomography (OCT) can identify risk factors for stent thrombosis such as stent malapposition, incomplete strut coverage and in-stent restenosis and may help guide discontinuation of DAPT. We conducted a single-center prospective study in cancer patients with recently placed (1-12 months) DES who required premature DAPT discontinuation. Patients were evaluated with diagnostic coronary angiogram and OCT. Individuals with appropriate stent strut coverage, expansion, apposition, and absence of in-stent restenosis or intraluminal masses were considered low risk and transiently discontinued DAPT to allow optimal cancer therapy. Patients who did not meet all these criteria were considered high risk and underwent further endovascular treatment when appropriate and bridging with low-molecular weight heparin. The incidence of adverse cardiovascular events was assessed after the procedure and at 12 months. A total of 40 patients were included. Twenty-seven patients (68%) were considered low risk by OCT criteria and DAPT was transiently discontinued. Thirteen patients (32%) were considered high risk with one or more OCT findings: uncovered stent struts (4 patients, 10%); stent underexpansion (3 patients, 8%); malapposition (8 patients, 20%); in-stent restenosis (2 patients, 5%). The high-risk patients with uncovered stent struts and malapposition underwent additional stent dilatation. There were no cardiovascular events in the low-risk group. One myocardial infarction occurred in the high-risk group. Fourteen non-cardiac deaths were registered before 12 months due to cancer progression or cancer therapy. OCT imaging allows identification of low-risk cancer patients with DES placed who may safely discontinue DAPT and proceed with cancer-related surgery or procedures.
Clinical heart failure prevention and contemporary therapy often involve breaking the vicious cyc... more Clinical heart failure prevention and contemporary therapy often involve breaking the vicious cycle of global haemodynamic consequences of myocardial decay. The lack of effective regenerative therapies results in a primary focus on preventing further deterioration of cardiac performance. The cellular transplantation hypothesis has been evaluated in many different preclinical models and a handful of important clinical trials. The primary expectation that cellular transplants will be embedded into failing myocardium and fuse with existing functioning cells appears unlikely. A multitude of cellular formulas, access routes and clinical surrogate endpoints for evaluation add to the complexity of cellular therapies. Several recent large clinical trials have provided insights into both the regenerative potential and clinical improvement from non-regenerative mechanisms. Initiating endogenous repair seems to be another meaningful alternative to recover structural integrity in myocardial injury. This option may be achieved using a transcoronary sinus catheter intervention, implying the understanding of basic principles in biology. With intermittent reduction of outflow in cardiac veins (PICSO), vascular cells appear to be activated and restart a programme similar to pathways in the developing heart. Structural regeneration may be possible without requiring exogenous agents, or a combination of both approaches may become clinical reality in the next decade.
Peripheral artery disease (PAD) is important to public health as a major contributor to cardiovas... more Peripheral artery disease (PAD) is important to public health as a major contributor to cardiovascular morbidity and mortality. Recent developments in magnetic resonance imaging (MRI) techniques permit improved assessment of PAD anatomy and physiology, and may serve as surrogate end points after proangiogenic therapies. The PACE study is a randomized, double-blind, placebo-controlled clinical trial designed to assess the physiologic impact and potential clinical efficacy of autologous bone marrow-derived ALDH(br) stem cells. The primary MRI end points of the study are as follows: (1) total collateral count, (2) calf muscle plasma volume (a measure of capillary perfusion) by dynamic contrast-enhanced MRI, and (3) peak hyperemic popliteal flow by phase-contrast MRI (PC-MRI). The interreader and intrareader and test-retest results demonstrated good-to-excellent reproducibility (interclass correlation coefficient range 0.61-0.98) for all magnetic resonance measures. The PAD participants (n=82) had lower capillary perfusion measured by calf muscle plasma volume (3.8% vs 5.6%) and peak hyperemic popliteal flow (4.1 vs 13.5mL/s) as compared with the healthy participants (n=16), with a significant level of collateralization. Reproducibility of the MRI primary end points in PACE was very good to excellent. The PAD participants exhibited decreased calf muscle capillary perfusion as well as arterial flow reserve when compared with healthy participants. The MRI tools used in PACE may advance PAD science by enabling accurate measurement of PAD microvascular anatomy and perfusion before and after stem cell or other PAD therapies.
Although several preclinical studies have shown that bone marrow cell (BMC) transplantation promo... more Although several preclinical studies have shown that bone marrow cell (BMC) transplantation promotes cardiac recovery after myocardial infarction, clinical trials with unfractionated bone marrow have shown variable improvements in cardiac function. To determine whether in a population of post-myocardial infarction patients, functional recovery after BM transplant is associated with specific BMC subpopulation, we examined the association between BMCs with left ventricular (LV) function in the LateTIME-CCTRN trial. In this population, we found that older individuals had higher numbers of BM CD133(+) and CD3(+) cells. Bone marrow from individuals with high body mass index had lower CD45(dim)/CD11b(dim) levels, whereas those with hypertension and higher C-reactive protein levels had higher numbers of CD133(+) cells. Smoking was associated with higher levels of CD133(+)/CD34(+)/VEGFR2(+) cells and lower levels of CD3(+) cells. Adjusted multivariate analysis indicated that CD11b(dim) cells were negatively associated with changes in LV ejection fraction and wall motion in both the infarct and border zones. Change in LV ejection fraction was positively associated with CD133(+), CD34(+), and CD45(+)/CXCR4(dim) cells as well as faster BMC growth rates in endothelial colony forming assays. In the LateTIME population, BM composition varied with patient characteristics and treatment. Irrespective of cell therapy, recovery of LV function was greater in patients with greater BM abundance of CD133(+) and CD34(+) cells and worse in those with higher levels of CD11b(dim) cells. Bone marrow phenotype might predict clinical response before BMC therapy and administration of selected BM constituents could potentially improve outcomes of other future clinical trials.
BACKGROUND AND OBJECTIVE:Left ventricular electromechanical mapping (EMM) determines myocardial v... more BACKGROUND AND OBJECTIVE:Left ventricular electromechanical mapping (EMM) determines myocardial viability on the basis of endocardial electrograms. The aim of the present study was to validate EMM in differentiating infarcted myocardium from viable myocardium by histopathological analysis.METHODS:Sixty days after implanting an ameroid constrictor over the left circumflex artery to create chronic ischemia in 19 pigs, EMM was performed to construct unipolar voltage (UPV), bipolar voltage (BPV) and linear local shortening (LLS) maps. Noninfarcted and infarcted myocardium were identified by histopathology. Threshold determinations comparing noninfarcted tissue with scarred tissue were made by measuring the area under the receiver operating characteristic curves.RESULTS:From the 19 hearts, 149 myocardial segments were divided into noninfarcted myocardium (n=128) and transmural infarct (n=21). UPV, BPV and LLS values (4.7±1.2 mV, 2.8±2.5 mV and 10.0±5.1%, respectively) of infarcted segments were significantly lower than those in noninfarcted myocardium (10.9±3.4 mV, 4.5±2.4 mV and 15.7±9.5%, respectively; P<0.01 for each comparison). The threshold values of UPV, BPV and LLS differentiating noninfarcted from infarcted myocardium were 6.2 mV (98% sensitivity, 95% specificity, 97% accuracy), 2.8 mV (80% sensitivity, 72% specificity, 79% accuracy) and 12.3% (68% sensitivity, 67% specificity, 68% accuracy), respectively. The relative dispersion of voltage was lower for UPV versus BPV.CONCLUSION:UPV can accurately differentiate infarcted from noninfarcted tissue in the chronic ischemic heart of pigs; however, BPV and LLS results were less accurate.
Background: The NHLBI-sponsored TIME Trial of the CCTRN investigated if the timing of stem cell d... more Background: The NHLBI-sponsored TIME Trial of the CCTRN investigated if the timing of stem cell delivery affects recovery of LV function following STEMI. It was a randomized, placebo-controlled trial of 120 patients with anterior STEMI randomized (2:1) to either 150 million autologous bone marrow mononuclear cells (BMCs) or cell-free placebo with intracoronary delivery on Day 3 or Day 7 following reperfusion with PCI in patients with LV dysfunction (LVEF ¬ Methods and Results: 85 patients (BMC=58; Placebo=27) returned for pre-specified 1 and 2-year follow-up MRIs. Data are presented as the aggregate of the Day 3 and Day 7 groups (means). While LVEF and regional wall motion increased in both groups between baseline and 6 months (p Conclusion: A significant reduction in infarct size and LV mass occurs during the initial six months following reperfused STEMI that is unaffected by BMC administration. After two years, the initial improvement in LV function remained stable in both groups ...
Left ventricular electromechanical mapping (EMM) determines myocardial viability on the basis of ... more Left ventricular electromechanical mapping (EMM) determines myocardial viability on the basis of endocardial electrograms. The aim of the present study was to validate EMM in differentiating infarcted myocardium from viable myocardium by histopathological analysis. Sixty days after implanting an ameroid constrictor over the left circumflex artery to create chronic ischemia in 19 pigs, EMM was performed to construct unipolar voltage (UPV), bipolar voltage (BPV) and linear local shortening (LLS) maps. Noninfarcted and infarcted myocardium were identified by histopathology. Threshold determinations comparing noninfarcted tissue with scarred tissue were made by measuring the area under the receiver operating characteristic curves. From the 19 hearts, 149 myocardial segments were divided into noninfarcted myocardium (n=128) and transmural infarct (n=21). UPV, BPV and LLS values (4.7+/-1.2 mV, 2.8+/-2.5 mV and 10.0+/-5.1%, respectively) of infarcted segments were significantly lower than ...
Journal of Cardiovascular Translational Research, 2021
In this study, we created a reproducible myocardial infarction (MI) model in pigs characterized b... more In this study, we created a reproducible myocardial infarction (MI) model in pigs characterized by a low mortality rate and significant changes in left ventricular function. After administering an arrhythmia prevention regimen, we created a 90-min balloon-induced percutaneous MI in 42 pigs below the first diagonal branch (D1) of the left anterior descending artery. Echocardiograms were performed before and 14 days after MI induction. Pigs with a > 30% decrease in left ventricular ejection fraction (LVEF) underwent electrophysiological mapping by the NOGA system. Our mortality rate was 4.8%. The incidence of ventricular fibrillation (VF) was 28.6%; all VF events were successfully resuscitated. At day 14, echocardiography and NOGA mapping confirmed transmural scar. LVEF decreased 41% from baseline. Radial and circumferential strain significantly decreased in the LAD distal to D1, and the LV showed dyssynchrony. An anti-arrhythmia regimen decreased mortality significantly, and our m...
Thrombus formation after stent deployment has been linked to the use of heparin and of antithromb... more Thrombus formation after stent deployment has been linked to the use of heparin and of antithrombotic agents, such as bivalirudin, during percutaneous coronary intervention. Fluoroscopy has been used to identify stent thrombosis, typically after patients become symptomatic. We describe our use of optical coherence tomography to diagnose and evaluate intraprocedural stent thrombosis in a 68-year-old man who was given bivalirudin just before a percutaneous coronary procedure. This imaging method enabled immediate therapeutic intervention.
SENECA (StEm cell iNjECtion in cAncer survivors) is a phase I, randomized, double-blind, placebo-... more SENECA (StEm cell iNjECtion in cAncer survivors) is a phase I, randomized, double-blind, placebo-controlled study to evaluate the safety and feasibility of delivering allogeneic mesenchymal stromal cells (allo-MSCs) transendocardially in subjects with anthracycline-induced cardiomyopathy (AIC). AIC is an incurable and often fatal syndrome, with a prognosis worse than that of ischemic or nonischemic cardiomyopathy. Recently, cell therapy with MSCs has emerged as a promising new approach to repair damaged myocardium. The study population is 36 cancer survivors with a diagnosis of AIC, left ventricular (LV) ejection fraction ≤40%, and symptoms of heart failure (NYHA class II-III) on optimally-tolerated medical therapy. Subjects must be clinically free of cancer for at least two years with a ≤ 30% estimated five-year risk of recurrence. The first six subjects participated in an open-label, lead-in phase and received 100 million allo-MSCs; the remaining 30 will be randomized 1:1 to recei...
Autologous bone marrow (BM) mesenchymal stem cells (MSCs) and c-kit cardiac progenitor cells (CPC... more Autologous bone marrow (BM) mesenchymal stem cells (MSCs) and c-kit cardiac progenitor cells (CPCs) are two promising cell types being evaluated for patients with heart failure (HF) secondary to ischemic cardiomyopathy. No information is available in humans regarding the relative efficacy of MSCs and CPCs and whether their combination is more efficacious than either cell type alone. CONCERT-HF (Combination Of meseNchymal and c-kit Cardiac stEm cells as Regenerative Therapy for Heart Failure) is a Phase II trial aimed at elucidating these issues by assessing the feasibility, safety, and efficacy of transendocardial administration of autologous MSCs and CPCs, alone and in combination, in patients with HF caused by chronic ischemic cardiomyopathy (coronary artery disease and old myocardial infarction). Using a randomized, double-blinded, placebo-controlled, multi-center, multi-treatment, and adaptive design, CONCERT-HF examines whether administration of MSCs alone, CPCs alone, or MSCs ...
Rationale: The TIME trial was the first cell therapy trial sufficiently powered to determine if t... more Rationale: The TIME trial was the first cell therapy trial sufficiently powered to determine if timing of cell delivery following ST-elevation myocardial infarction (STEMI) affects recovery of left ventricular (LV) function. Objective: To report the 2-year clinical and cardiac magnetic resonance imaging (cMRI) results and their modification by microvascular obstruction (MVO). Methods and Results: TIME was a randomized, double-blind, placebo-controlled trial comparing 150 million bone marrow mononuclear cells (BMC) vs. placebo in 120 patients with anterior STEMIs resulting in LV dysfunction. Primary endpoints included changes in global (LV ejection fraction (LVEF)) and regional (infarct and border zone) function. Secondary endpoints included changes in LV volumes, infarct size and major adverse cardiac events. Here, we analyzed the continued trajectory of these measures out to 2 years and the influence of MVO present at baseline on these long-term outcomes. At 2 years (n=85), LVEF wa...
Cancer patients with recently placed drug-eluting stents (DESs) often require premature dual anti... more Cancer patients with recently placed drug-eluting stents (DESs) often require premature dual antiplatelet therapy (DAPT) discontinuation for cancer-related procedures. Optical coherence tomography (OCT) can identify risk factors for stent thrombosis such as stent malapposition, incomplete strut coverage and in-stent restenosis and may help guide discontinuation of DAPT. We conducted a single-center prospective study in cancer patients with recently placed (1-12 months) DES who required premature DAPT discontinuation. Patients were evaluated with diagnostic coronary angiogram and OCT. Individuals with appropriate stent strut coverage, expansion, apposition, and absence of in-stent restenosis or intraluminal masses were considered low risk and transiently discontinued DAPT to allow optimal cancer therapy. Patients who did not meet all these criteria were considered high risk and underwent further endovascular treatment when appropriate and bridging with low-molecular weight heparin. The incidence of adverse cardiovascular events was assessed after the procedure and at 12 months. A total of 40 patients were included. Twenty-seven patients (68%) were considered low risk by OCT criteria and DAPT was transiently discontinued. Thirteen patients (32%) were considered high risk with one or more OCT findings: uncovered stent struts (4 patients, 10%); stent underexpansion (3 patients, 8%); malapposition (8 patients, 20%); in-stent restenosis (2 patients, 5%). The high-risk patients with uncovered stent struts and malapposition underwent additional stent dilatation. There were no cardiovascular events in the low-risk group. One myocardial infarction occurred in the high-risk group. Fourteen non-cardiac deaths were registered before 12 months due to cancer progression or cancer therapy. OCT imaging allows identification of low-risk cancer patients with DES placed who may safely discontinue DAPT and proceed with cancer-related surgery or procedures.
Clinical heart failure prevention and contemporary therapy often involve breaking the vicious cyc... more Clinical heart failure prevention and contemporary therapy often involve breaking the vicious cycle of global haemodynamic consequences of myocardial decay. The lack of effective regenerative therapies results in a primary focus on preventing further deterioration of cardiac performance. The cellular transplantation hypothesis has been evaluated in many different preclinical models and a handful of important clinical trials. The primary expectation that cellular transplants will be embedded into failing myocardium and fuse with existing functioning cells appears unlikely. A multitude of cellular formulas, access routes and clinical surrogate endpoints for evaluation add to the complexity of cellular therapies. Several recent large clinical trials have provided insights into both the regenerative potential and clinical improvement from non-regenerative mechanisms. Initiating endogenous repair seems to be another meaningful alternative to recover structural integrity in myocardial injury. This option may be achieved using a transcoronary sinus catheter intervention, implying the understanding of basic principles in biology. With intermittent reduction of outflow in cardiac veins (PICSO), vascular cells appear to be activated and restart a programme similar to pathways in the developing heart. Structural regeneration may be possible without requiring exogenous agents, or a combination of both approaches may become clinical reality in the next decade.
Peripheral artery disease (PAD) is important to public health as a major contributor to cardiovas... more Peripheral artery disease (PAD) is important to public health as a major contributor to cardiovascular morbidity and mortality. Recent developments in magnetic resonance imaging (MRI) techniques permit improved assessment of PAD anatomy and physiology, and may serve as surrogate end points after proangiogenic therapies. The PACE study is a randomized, double-blind, placebo-controlled clinical trial designed to assess the physiologic impact and potential clinical efficacy of autologous bone marrow-derived ALDH(br) stem cells. The primary MRI end points of the study are as follows: (1) total collateral count, (2) calf muscle plasma volume (a measure of capillary perfusion) by dynamic contrast-enhanced MRI, and (3) peak hyperemic popliteal flow by phase-contrast MRI (PC-MRI). The interreader and intrareader and test-retest results demonstrated good-to-excellent reproducibility (interclass correlation coefficient range 0.61-0.98) for all magnetic resonance measures. The PAD participants (n=82) had lower capillary perfusion measured by calf muscle plasma volume (3.8% vs 5.6%) and peak hyperemic popliteal flow (4.1 vs 13.5mL/s) as compared with the healthy participants (n=16), with a significant level of collateralization. Reproducibility of the MRI primary end points in PACE was very good to excellent. The PAD participants exhibited decreased calf muscle capillary perfusion as well as arterial flow reserve when compared with healthy participants. The MRI tools used in PACE may advance PAD science by enabling accurate measurement of PAD microvascular anatomy and perfusion before and after stem cell or other PAD therapies.
Although several preclinical studies have shown that bone marrow cell (BMC) transplantation promo... more Although several preclinical studies have shown that bone marrow cell (BMC) transplantation promotes cardiac recovery after myocardial infarction, clinical trials with unfractionated bone marrow have shown variable improvements in cardiac function. To determine whether in a population of post-myocardial infarction patients, functional recovery after BM transplant is associated with specific BMC subpopulation, we examined the association between BMCs with left ventricular (LV) function in the LateTIME-CCTRN trial. In this population, we found that older individuals had higher numbers of BM CD133(+) and CD3(+) cells. Bone marrow from individuals with high body mass index had lower CD45(dim)/CD11b(dim) levels, whereas those with hypertension and higher C-reactive protein levels had higher numbers of CD133(+) cells. Smoking was associated with higher levels of CD133(+)/CD34(+)/VEGFR2(+) cells and lower levels of CD3(+) cells. Adjusted multivariate analysis indicated that CD11b(dim) cells were negatively associated with changes in LV ejection fraction and wall motion in both the infarct and border zones. Change in LV ejection fraction was positively associated with CD133(+), CD34(+), and CD45(+)/CXCR4(dim) cells as well as faster BMC growth rates in endothelial colony forming assays. In the LateTIME population, BM composition varied with patient characteristics and treatment. Irrespective of cell therapy, recovery of LV function was greater in patients with greater BM abundance of CD133(+) and CD34(+) cells and worse in those with higher levels of CD11b(dim) cells. Bone marrow phenotype might predict clinical response before BMC therapy and administration of selected BM constituents could potentially improve outcomes of other future clinical trials.
BACKGROUND AND OBJECTIVE:Left ventricular electromechanical mapping (EMM) determines myocardial v... more BACKGROUND AND OBJECTIVE:Left ventricular electromechanical mapping (EMM) determines myocardial viability on the basis of endocardial electrograms. The aim of the present study was to validate EMM in differentiating infarcted myocardium from viable myocardium by histopathological analysis.METHODS:Sixty days after implanting an ameroid constrictor over the left circumflex artery to create chronic ischemia in 19 pigs, EMM was performed to construct unipolar voltage (UPV), bipolar voltage (BPV) and linear local shortening (LLS) maps. Noninfarcted and infarcted myocardium were identified by histopathology. Threshold determinations comparing noninfarcted tissue with scarred tissue were made by measuring the area under the receiver operating characteristic curves.RESULTS:From the 19 hearts, 149 myocardial segments were divided into noninfarcted myocardium (n=128) and transmural infarct (n=21). UPV, BPV and LLS values (4.7±1.2 mV, 2.8±2.5 mV and 10.0±5.1%, respectively) of infarcted segments were significantly lower than those in noninfarcted myocardium (10.9±3.4 mV, 4.5±2.4 mV and 15.7±9.5%, respectively; P<0.01 for each comparison). The threshold values of UPV, BPV and LLS differentiating noninfarcted from infarcted myocardium were 6.2 mV (98% sensitivity, 95% specificity, 97% accuracy), 2.8 mV (80% sensitivity, 72% specificity, 79% accuracy) and 12.3% (68% sensitivity, 67% specificity, 68% accuracy), respectively. The relative dispersion of voltage was lower for UPV versus BPV.CONCLUSION:UPV can accurately differentiate infarcted from noninfarcted tissue in the chronic ischemic heart of pigs; however, BPV and LLS results were less accurate.
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