Jonathan Passeri

Apoptosis in Human Atherosclerosis and Restenosis

BACKGROUND Apoptosis has been recognized in normal, including rapidly proliferating, cell populations and is inferred to be potentially responsible for the maintenance of stable cell numbers in tissues with various degrees of proliferative activity. Previous studies performed in rats indicated that despite the persistence of a relatively high level of injury-induced proliferative activity, total arterial smooth muscle content at 12 weeks remained unchanged from that measured at 2 weeks, suggesting that accrual of vascular smooth muscle cells is mitigated by cell death. The extent to which apoptosis may be observed in human atherosclerosis and/or restenosis, however, has not been previously established. METHODS AND RESULTS We performed immunohistochemical studies on 56 specimens retrieved from patients undergoing directional atherectomy for primary atherosclerotic lesions or recurrent arterial narrowing after percutaneous revascularization (restenosis). Immunohistochemical staining disclosed evidence of apoptosis in 35 (63%) of the 56 specimens studied. When present, immunohistochemical evidence of apoptosis was typically limited to < 2% of cells in the specimen. The finding of apoptosis, however, was not distributed equally among four groups of specimens studied. Specimens retrieved from patients with restenosis were more frequently observed to contain foci of apoptosis than specimens retrieved from patients with primary atherosclerotic lesions. Among 14 peripheral arterial specimens from patients with restenosis, 13 (93%) contained foci of apoptosis; in contrast, apoptosis was observed in only 6 (43%) of 14 peripheral specimens from patients with primary lesions (P = .0046). Among coronary arterial specimens, apoptosis was observed in 12 (86%) of 14 specimens from patients with restenosis versus 6 (29%) of 14 specimens from patients with primary obstructions (P < .0075). CONCLUSIONS Apoptosis is a feature of human vascular pathology, including restenotic lesions and, to a lesser extent, primary atherosclerotic lesions. The findings of the present study suggest that apoptosis may modulate the cellularity of lesions that produce human vascular obstruction, particularly those with evidence of more extensive proliferative activity.

Direct Intramuscular Gene Transfer of Naked DNA Encoding Vascular Endothelial Growth Factor Augments Collateral Development and Tissue Perfusion

BACKGROUND Striated muscle has been shown to be capable of taking up and expressing foreign genes transferred in the form of naked plasmid DNA, although typically with a low level of gene expression. In the case of genes that encode secreted proteins, however, low transfection efficiency may not preclude bio-activity of the secreted gene product. Accordingly, we investigated the hypothesis that intramuscular (IM) gene therapy with naked plasmid DNA encoding vascular endothelial growth factor (VEGF) could augment collateral development and tissue perfusion in an animal model of hindlimb ischemia. METHODS AND RESULTS Ten days after ischemia was induced in one rabbit hindlimb, 500 micrograms of phVEGF165, or the reporter gene LacZ, was injected IM into the ischemic hindlimb muscles. Thirty days later, angiographically recognizable collateral vessels and histologically identifiable capillaries were increased in VEGF transfectants compared with controls. This augmented vascularity improved perfusion to the ischemic limb, documented by a superior calf blood pressure ratio for phVEGF165 (0.85 +/- 0.05) versus controls (0.64 +/- 0.05, P < .01), improved blood flow in the ischemic limb (measured with an intra-arterial Doppler wire) at rest (phVEGF165 = 21.3 +/- 3.9 mL/min, control = 14.6 +/- 1.6 mL/min, P < .01) and after a vasodilator (phVEGF165 = 54.2 +/- 12.0 mL/min, control = 37.3 +/- 8.9 mL/min, P < .01) and increased microspheres in the adductor (phVEGF165 = 4.3 +/- 1.6 mL.min-1.100 g of tissue-1, control = 2.9 +/- 1.2 mL.min-1.100 g of tissue-1, P < .05) and gastrocnemius (phVEGF165 = 3.9 +/- 1.0 mL.min-1.100 g of tissue-1, control = 2.8 +/- 1.4 mL.min-1.100 g of tissue-1, P < .05) muscles of the ischemic limb. CONCLUSIONS Ischemic skeletal muscle represents a promising target for gene therapy with naked plasmid DNA. IM transfection of genes encoding angiogenic cytokines, particularly those that are naturally secreted by intact cells, may constitute an alternative treatment strategy for patients with extensive peripheral vascular disease in whom the use of intravascular catheter-based gene transfer is compromised and/or prohibited.

Assessment of Echocardiography and Biomarkers for the Extended Prediction of Cardiotoxicity in Patients treated with Anthracyclines, Taxanes and Trastuzumab

Background—Because cancer patients survive longer, the impact of cardiotoxicity associated with the use of cancer treatments escalates. The present study investigates whether early alterations of myocardial strain and blood biomarkers predict incident cardiotoxicity in patients with breast cancer during treatment with anthracyclines, taxanes, and trastuzumab. Methods and Results—Eighty-one women with newly diagnosed human epidermal growth factor receptor 2–positive breast cancer, treated with anthracyclines followed by taxanes and trastuzumab were enrolled to be evaluated every 3 months during their cancer therapy (total of 15 months) using echocardiograms and blood samples. Left ventricular ejection fraction, peak systolic longitudinal, radial, and circumferential myocardial strain were calculated. Ultrasensitive troponin I, N-terminal pro–B-type natriuretic peptide, and the interleukin family member (ST2) were also measured. Left ventricular ejection fraction decreased (64 ± 5% to 59 ± 6%; P<0.0001) over 15 months. Twenty-six patients (32%, [22%–43%]) developed cardiotoxicity as defined by the Cardiac Review and Evaluation Committee Reviewing Trastuzumab; of these patients, 5 (6%, [2%–14%]) had symptoms of heart failure. Peak systolic longitudinal myocardial strain and ultrasensitive troponin I measured at the completion of anthracyclines treatment predicted the subsequent development of cardiotoxicity; no significant associations were observed for left ventricular ejection fraction, N-terminal pro–B-type natriuretic peptide, and ST2. Longitudinal strain was <19% in all patients who later developed heart failure. Conclusions—In patients with breast cancer treated with anthracyclines, taxanes, and trastuzumab, systolic longitudinal myocardial strain and ultrasensitive troponin I measured at the completion of anthracyclines therapy are useful in the prediction of subsequent cardiotoxicity and may help guide treatment to avoid cardiac side-effects.

Accelerated Restitution of Endothelial Integrity and Endothelium-Dependent Function After phVEGF165 Gene Transfer

BACKGROUND Delinquent reendothelialization (rET) has been shown to have a permissive, if not facilitatory, impact on smooth muscle cell proliferation. This inverse relation has been attributed to certain functions of the endothelium, including barrier regulation of permeability, thrombogenicity, and leukocyte adherence, as well as production of growth-inhibitory molecules. Accordingly, the present investigation was designed to test the hypothesis that an endothelial cell (EC) mitogen could serve as the basis for a novel gene therapy strategy designed to facilitate EC regeneration, reduce neointimal thickening, and promote recovery of EC dysfunction after balloon injury. METHODS AND RESULTS New Zealand White rabbits underwent simultaneous balloon injury and gene transfer of one femoral artery with phVEGF165, encoding the 165-amino acid isoform of vascular endothelial growth factor (VEGF), or pGSVLacZ. In each animal transfected with phVEGF165 or pGSVLacZ, the contralateral femoral artery was also subjected to balloon injury but not to gene transfer. For pGSVLacZ, rET remained incomplete at 4 weeks after transfection; in contrast, phVEGF165 produced prompt rET, which was 95% complete by 1 week. Furthermore, rET in the contralateral, balloon-injured, nontransfected limb of the VEGF group was similarly accelerated. Consequently, intimal thickening was diminished, thrombotic occlusion was less frequent, and recovery of EC-dependent vasomotor reactivity was accelerated in VEGF transfectants compared with control animals. A similar benefit was observed for the contralateral, balloon-injured, nontransfected limb. CONCLUSIONS Catheter-mediated, site-specific arterial gene transfer of phVEGF165 can accelerate rET at local and remote sites, leading to inhibition of neointimal thickening, reduction in thrombogenicity, and restoration of endothelium-dependent vasomotor reactivity. These findings support the notion that gene transfer encoding for an EC-specific mitogen may be useful for preventing the complications, including restenosis, of balloon angioplasty.

Stent Endothelialization: Time Course, Impact of Local Catheter Delivery, Feasibility of Recombinant Protein Administration, and Response to Cytokine Expedition

BACKGROUND Because prior studies have established the critical role of the endothelium in preventing vascular thrombosis and intimal thickening, we designed a series of experiments to determine the feasibility of percutaneous local catheter delivery of recombinant protein to accelerate development of an intact endothelial monolayer after stent implantation. METHODS AND RESULTS Balloon injury followed by percutaneous delivery of a 15-mm-long, balloon-expandable metallic stent was performed in 64 rabbit external iliac arteries (baseline diameter, 2.67 +/- 0.07 mm). Planimetric time-course analysis disclosed < 20% stent endothelialization at 4 days, < 40% at 7 days, and near-complete endothelialization at 28 days. The reporter protein horseradish peroxidase and the endothelial cell-specific recombinant protein vascular endothelial growth factor (VEGF) were each effectively delivered from a local delivery catheter (channel balloon catheter, ChB) after stent implantation. Although local catheter delivery (of vehicle control) itself mildly retarded the extent of stent endothelialization (10.6 +/- 2.9%) versus no local delivery (25.5 +/- 6.6%, P = .045), local ChB delivery of 100 micrograms VEGF overcame this catheter effect: By day 7, stent endothelialization was nearly complete (91.8 +/- 3.8%) (P < .0001 versus no local delivery). Consequently, stent thrombus was reduced in the VEGF-treated group (mural thrombus, 5.3 +/- 3.7%) versus no local delivery (29.3 +/- 6.8%, P = .006). Occlusive thrombus was seen only in the absence of local VEGF administration. CONCLUSIONS (1) Local delivery of recombinant protein to the arterial wall is feasible after stent implantation, and (2) local delivery of the endothelial cell mitogen VEGF accelerates stent endothelialization, reducing stent thrombosis. These results thus establish a novel means by which the safety and/or bioactivity of endovascular stents may be further enhanced.

Outcomes of Transcatheter and Surgical Aortic Valve Replacement in High-Risk Patients With Aortic Stenosis and Left Ventricular Dysfunction Results From the Placement of Aortic Transcatheter Valves (PARTNER) Trial (Cohort A)

Background—The Placement of Aortic Transcatheter Valves (PARTNER) trial demonstrated similar survival after transcatheter and surgical aortic valve replacement (TAVR and SAVR, respectively) in high-risk patients with symptomatic, severe aortic stenosis. The aim of this study was to evaluate the effect of left ventricular (LV) dysfunction on clinical outcomes after TAVR and SAVR and the impact of aortic valve replacement technique on LV function. Methods and Results—The PARTNER trial randomized high-risk patients with severe aortic stenosis to TAVR or SAVR. Patients were stratified by the presence of LV ejection fraction (LVEF) <50%. All-cause mortality was similar for TAVR and SAVR at 30-days and 1 year regardless of baseline LV function and valve replacement technique. In patients with LV dysfunction, mean LVEF increased from 35.7±8.5% to 48.6±11.3% (P<0.0001) 1 year after TAVR and from 38.0±8.0% to 50.1±10.8% after SAVR (P<0.0001). Higher baseline LVEF (odds ratio, 0.90 [95% confidence interval, 0.86, 0.95]; P<0.0001) and previous permanent pacemaker (odds ratio, 0.34 [95% confidence interval, 0.15, 0.81]) were independently associated with reduced likelihood of ≥10% absolute LVEF improvement by 30 days; higher mean aortic valve gradient was associated with increased odds of LVEF improvement (odds ratio, 1.04 per 1 mm Hg [95% confidence interval, 1.01, 1.08]). Failure to improve LVEF by 30 days was associated with adverse 1-year outcomes after TAVR but not SAVR. Conclusions—In high-risk patients with severe aortic stenosis and LV dysfunction, mortality rates and LV functional recovery were comparable between valve replacement techniques. TAVR is a feasible alternative for patients with symptomatic severe aortic stenosis and LV dysfunction who are at high risk for SAVR. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00530894.

Therapeutic Angiogenesis: A New Treatment Approach for Ischemic Heart Disease—part I

Angiogenesis is the biologic process of forming new blood vessels and is being investigated as an innovative therapeutic approach to help manage ischemic heart disease and peripheral vascular disease. Research studies have identified various angiogenic growth factors and progenitor cells that can enhance new blood vessel formation. Preclinical investigations in animal models have explored the potential use of growth factors with and without progenitor cells to treat myocardial ischemia. The results of clinical trials with growth factor infusions and gene therapy techniques to enhance growth factor production have shown some promise, but therapeutic angiogenesis remains at an early stage of development.

Longitudinal Changes in Multiple Biomarkers Are Associated with Cardiotoxicity in Breast Cancer Patients Treated with Doxorubicin, Taxanes, and Trastuzumab

BACKGROUND Biomarkers may play an important role in identifying patients at risk for cancer therapy cardiotoxicity. Our objectives were to define the patterns of change in biomarkers with cancer therapy and their associations with cardiotoxicity. METHODS In a multicenter cohort of 78 breast cancer patients undergoing doxorubicin and trastuzumab therapy, 8 biomarkers were evaluated at baseline and every 3 months over a maximum follow-up of 15 months. These biomarkers, hypothesized to be mechanistically relevant to cardiotoxicity, included high-sensitivity cardiac troponin I (hs-cTnI), high-sensitivity C-reactive protein (hsCRP), N-terminal pro-B-type natriuretic peptide (NT-proBNP), growth differentiation factor 15 (GDF-15), myeloperoxidase (MPO), placental growth factor (PlGF), soluble fms-like tyrosine kinase receptor-1 (sFlt-1), and galectin 3 (gal-3). We determined if biomarker increases were associated with cardiotoxicity at the same visit and the subsequent visit over the entire course of therapy. Cardiotoxicity was defined by the Cardiac Review and Evaluation Criteria; alternative definitions were also considered. RESULTS Across the entire cohort, all biomarkers except NT-proBNP and gal-3 demonstrated increases by 3 months; these increases persisted for GDF-15, PlGF, and hs-cTnI at 15 months. Increases in MPO, PlGF, and GDF-15 were associated with cardiotoxicity at the same visit [MPO hazard ratio 1.38 (95% CI 1.10-1.71), P = 0.02; PlGF 3.78 (1.30-11.0), P = 0.047; GDF-15 1.71 (1.15-2.55), P = 0.01] and the subsequent visit. MPO was robust to alternative outcome definitions. CONCLUSIONS Increases in MPO are associated with cardiotoxicity over the entire course of doxorubicin and trastuzumab therapy. Assessment with PlGF and GDF-15 may also be of value. These findings motivate validation studies in additional cohorts.

Gender effects on cardiac valvular function in hyperprolactinaemic patients receiving cabergoline: a retrospective study

Background  Ergot‐derived dopamine agonists are associated with increased risk of valvular dysfunction in Parkinson’s disease. The risk of valvular disease associated with lower doses of cabergoline used to treat prolactinomas remains controversial.

Echocardiographic Assessment of Percutaneous Patent Foramen Ovale and Atrial Septal Defect Closure Complications

Atrial septal defect (ASD) is a common congenital defect (1 in 1000 live births) and accounts for up to 40% of clinically relevant acyanotic shunts in adults.1 Patent foramen ovale (PFO) is much more common and is present in more than 25% of adults.2,3 The clinical syndromes associated with ASD/PFO represent a significant health burden. Surgical closure is the most common therapy for these defects, and it is associated with low morbidity and mortality. However, it remains a surgical procedure requiring cardiopulmonary bypass, a significant postoperative recovery, and a sternotomy scar that may be undesirable to young patients. Catheter-based techniques for the treatment of ASD/PFO were pioneered by King and Mills in 1975.4 Since then, significant device development and modifications have been made (Table 1). Percutaneous therapy is now the preferred strategy for ASD/PFO closure, by patients and physicians alike, in the absence of complicated anatomy or another indication for traditional cardiac surgery, because it is technically simple and associated with negligible morbidity and mortality.5 Longer-term follow-up, however, remains necessary to more completely evaluate the safety and efficacy of such devices. View this table: Table 1. Summary of Devices Most Frequently Used for Percutaneous Closure of ASD or PFO The role of 2-dimensional (2D) transthoracic echocardiography (TTE) and transesophageal echocardiography (TEE) during the assessment and management of ASD/PFO has been demonstrated.6–8 Although universal practice standards, in the form of consensus committee guidelines or professional society recommendations, still have to be established for the use of echocardiography in this context, it is used by a majority of groups who perform these procedures. In our institution, TTE with color Doppler and/or agitated saline contrast injection is most frequently the method used to diagnose interatrial communication. Once the diagnosis has been made and percutaneous closure is deemed clinically appropriate, a careful …