Timothy D. Henry

The VIVA Trial

Background—Recombinant human vascular endothelial growth factor protein (rhVEGF) stimulates angiogenesis in animal models and was well tolerated in Phase I clinical trials. VIVA (Vascular endothelial growth factor in Ischemia for Vascular Angiogenesis) is a double-blind, placebo-controlled trial designed to evaluate the safety and efficacy of intracoronary and intravenous infusions of rhVEGF. Methods and Results—A total of 178 patients with stable exertional angina, unsuitable for standard revascularization, were randomized to receive placebo, low-dose rhVEGF (17 ng · kg−1 · min−1), or high-dose rhVEGF (50 ng · kg−1 · min−1) by intracoronary infusion on day 0, followed by intravenous infusions on days 3, 6, and 9. Exercise treadmill tests, angina class, and quality of life assessments were performed at baseline, day 60, and day 120. Myocardial perfusion imaging was performed at baseline and day 60. At day 60, the change in exercise treadmill test (ETT) time from baseline was not different between groups (placebo, +48 seconds; low dose, +30 seconds; high dose, +30 seconds). Angina class and quality of life were significantly improved within each group, with no difference between groups. By day 120, placebo-treated patients demonstrated reduced benefit in all three measures, with no significant difference compared with low-dose rhVEGF. In contrast, high-dose rhVEGF resulted in significant improvement in angina class (P =0.05) and nonsignificant trends in ETT time (P =0.15) and angina frequency (P =0.09) as compared with placebo. Conclusions—rhVEGF seems to be safe and well tolerated. rhVEGF offered no improvement beyond placebo in all measurements by day 60. By day 120, high-dose rhVEGF resulted in significant improvement in angina and favorable trends in ETT time and angina frequency.

Intramyocardial transplantation of autologous CD34+ stem cells for intractable angina : A phase I/IIa double-blind, randomized controlled trial

Background— A growing population of patients with coronary artery disease experiences angina that is not amenable to revascularization and is refractory to medical therapy. Preclinical studies have indicated that human CD34+ stem cells induce neovascularization in ischemic myocardium, which enhances perfusion and function. Methods and Results— Twenty-four patients (19 men and 5 women aged 48 to 84 years) with Canadian Cardiovascular Society class 3 or 4 angina who were undergoing optimal medical treatment and who were not candidates for mechanical revascularization were enrolled in a double-blind, randomized (3:1), placebo-controlled dose-escalating study. Patients received granulocyte colony-stimulating factor 5 &mgr;g · kg−1 · d−1 for 5 days with leukapheresis on the fifth day. Selection of CD34+ cells was performed with a Food and Drug Administration–approved device. Electromechanical mapping was performed to identify ischemic but viable regions of myocardium for injection of cells (versus saline). The total dose of cells was distributed in 10 intramyocardial, transendocardial injections. Patients were required to have an implantable cardioverter-defibrillator or to temporarily wear a LifeVest wearable defibrillator. No incidence was observed of myocardial infarction induced by mobilization or intramyocardial injection. The intramyocardial injection of cells or saline did not result in cardiac enzyme elevation, perforation, or pericardial effusion. No incidence of ventricular tachycardia or ventricular fibrillation occurred during the administration of granulocyte colony-stimulating factor or intramyocardial injections. One patient with a history of sudden cardiac death/ventricular tachycardia/ventricular fibrillation had catheter-induced ventricular tachycardia during mapping that required cardioversion. Serious adverse events were evenly distributed. Efficacy parameters including angina frequency, nitroglycerine usage, exercise time, and Canadian Cardiovascular Society class showed trends that favored CD34+ cell–treated patients versus control subjects given placebo. Conclusions— A randomized trial of intramyocardial injection of autologous CD34+ cells in patients with intractable angina was completed that provides evidence for feasibility, safety, and bioactivity. A larger phase IIb study is currently under way to further evaluate this therapy.

Platelet reactivity and clinical outcomes after coronary artery implantation of drug-eluting stents (ADAPT-DES): a prospective multicentre registry study

BACKGROUND The relation between platelet reactivity and stent thrombosis, major bleeding, and other adverse events after coronary artery implantation of drug-eluting stents has been incompletely characterised. We aimed to determine the relation between platelet reactivity during dual therapy with aspirin and clopidogrel and clinical outcomes after successful coronary drug-eluting stent implantation. METHODS ADAPT-DES was a prospective, multicentre registry of patients successfully treated with one or more drug-eluting stents and given aspirin and clopidogrel at 10-15 US and European hospitals. We assessed platelet reactivity in those patients after successful percutaneous coronary intervention using VerifyNow point-of-care assays, and assigned different cutoffs to define high platelet reactivity. The primary endpoint was definite or probable stent thrombosis; other endpoints were all-cause mortality, myocardial infarction, and clinically relevant bleeding. We did a propensity-adjusted multivariable analysis to determine the relation between platelet reactivity and subsequent adverse events. This study is registered with ClinicalTrials.gov, number NCT00638794. FINDINGS Between Jan 7, 2008, and Sept 16, 2010, 8665 patients were prospectively enrolled at 11 sites, of which 8583 were eligible. At 1-year follow-up, stent thrombosis had occurred in 70 (0·8%) patients, myocardial infarction in 269 (3·1%), clinically relevant bleeding in 531 (6·2%), and death in 161 (1·9%) patients. High platelet reactivity on clopidogrel was strongly related to stent thrombosis (adjusted HR 2·49 [95% CI 1·43-4·31], p=0·001) and myocardial infarction (adjusted HR 1·42 [1·09-1·86], p=0·01), was inversely related to bleeding (adjusted HR 0·73 [0·61-0·89], p=0·002), but was not related to mortality (adjusted HR 1·20 [0·85-1·70], p=0·30). High platelet reactivity on aspirin was not significantly associated with stent thrombosis (adjusted HR 1·46 [0·58-3·64], p=0·42), myocardial infarction, or death, but was inversely related to bleeding (adjusted HR 0·65 [0·43-0·99], p=0·04). INTERPRETATION The findings from this study emphasise the counter-balancing effects of haemorrhagic and ischaemic complications after stent implantation, and suggest that safer drugs or tailored strategies for the use of more potent agents must be developed if the benefits of greater platelet inhibition in patients with cardiovascular disease are to be realised. FUNDING Boston Scientific, Abbott Vascular, Medtronic, Cordis, Biosensors, The Medicines Company, Daiichi-Sankyo, Eli Lilly, Volcano, and Accumetrics.

Results of a Double-Blind, Placebo-Controlled Study to Assess the Safety of Intramuscular Injection of Hepatocyte Growth Factor Plasmid to Improve Limb Perfusion in Patients With Critical Limb Ischemia

Background— The Study to Assess the Safety of Intramuscular Injection of Hepatocyte Growth Factor Plasmid to Improve Limb Perfusion in Patients With Critical Limb Ischemia (HGF-STAT trial) determined the effect of hepatocyte growth factor (HGF) plasmid on safety and limb tissue perfusion as measured by transcutaneous oxygen tension (TcPo2) in patients with critical limb ischemia (CLI). Methods and Results— Randomized patients with rest pain or ischemic ulcers and TcPo2 <40 mm Hg and/or toe pressure <50 mm Hg received placebo or HGF-plasmid intramuscular injection as follows: 0.4 mg at days 0, 14, and 28 (low dose); 4.0 mg at days 0 and 28 (middle dose); or 4.0 mg at days 0, 14, and 28 (high dose). Patients were evaluated for safety, changes in TcPo2 and ankle and toe pressure, amputation, and wound healing. Ninety-three of 104 treated patients were evaluated for safety (mean age 70 years, 63% male, 53% diabetic, 64% with tissue loss, mean ankle-brachial index 0.41, and mean toe pressure 26 mm Hg). Adverse events occurred in 86% of the patients, most of which were related to CLI or comorbid conditions and were not different between groups. TcPo2 (mean±SE) increased at 6 months in the high-dose group (24.0±4.2 mm Hg, 95% CI 15.5 to 32.4 mm Hg) compared with the placebo (9.4±4.2 mm Hg, 95% CI 0.9 to 17.8), low-dose (11.1±3.7 mm Hg, CI 3.7 to 18.7 mm Hg), and middle-dose (7.3±4.8 mm Hg, CI −2.2 to 17.0 mm Hg) groups (ANCOVA P=0.0015). There was no difference between groups in secondary end points, including ankle-brachial index, toe-brachial index, pain relief, wound healing, or major amputation. Conclusions— Intramuscular injection of HGF plasmid was safe and well tolerated. Larger studies to determine whether HGF plasmid can improve wound healing and limb salvage in patients with CLI are warranted.

A target-mediated model to describe the pharmacokinetics and hemodynamic effects of recombinant human vascular endothelial growth factor in humans

The Vascular Endothelial Growth Factor (VEGF) in Ischemiafor Vascular Angiogenesis (VIVA) trial was a double‐blind, placebo‐controlled, phase II clinical trial designed to evaluate the safety, efficacy, and pharmacokinetics of combinedintracoronary and intravenous infusions of recombinant human vascular endothelial growth factor (rhVEGF165) for therapeutic angiogenesis. This study describes the use of a mechanism‐based model to characterize the nonlinear kinetics observed after intravenous administration of rhVEGF165. The model predicts that rhVEGF165 distribution occurs through both saturable binding to high‐affinity receptors and reversible interactions with low‐affinity binding sites.

Meta-Analysis of Cell-based CaRdiac stUdiEs (ACCRUE) in Patients With Acute Myocardial Infarction Based on Individual Patient Data

RATIONALE The meta-Analysis of Cell-based CaRdiac study is the first prospectively declared collaborative multinational database, including individual data of patients with ischemic heart disease treated with cell therapy. OBJECTIVE We analyzed the safety and efficacy of intracoronary cell therapy after acute myocardial infarction (AMI), including individual patient data from 12 randomized trials (ASTAMI, Aalst, BOOST, BONAMI, CADUCEUS, FINCELL, REGENT, REPAIR-AMI, SCAMI, SWISS-AMI, TIME, LATE-TIME; n=1252). METHODS AND RESULTS The primary end point was freedom from combined major adverse cardiac and cerebrovascular events (including all-cause death, AMI recurrance, stroke, and target vessel revascularization). The secondary end point was freedom from hard clinical end points (death, AMI recurrence, or stroke), assessed with random-effects meta-analyses and Cox regressions for interactions. Secondary efficacy end points included changes in end-diastolic volume, end-systolic volume, and ejection fraction, analyzed with random-effects meta-analyses and ANCOVA. We reported weighted mean differences between cell therapy and control groups. No effect of cell therapy on major adverse cardiac and cerebrovascular events (14.0% versus 16.3%; hazard ratio, 0.86; 95% confidence interval, 0.63-1.18) or death (1.4% versus 2.1%) or death/AMI recurrence/stroke (2.9% versus 4.7%) was identified in comparison with controls. No changes in ejection fraction (mean difference: 0.96%; 95% confidence interval, -0.2 to 2.1), end-diastolic volume, or systolic volume were observed compared with controls. These results were not influenced by anterior AMI location, reduced baseline ejection fraction, or the use of MRI for assessing left ventricular parameters. CONCLUSIONS This meta-analysis of individual patient data from randomized trials in patients with recent AMI revealed that intracoronary cell therapy provided no benefit, in terms of clinical events or changes in left ventricular function. CLINICAL TRIAL REGISTRATION URL: http://www.clinicaltrials.gov. Unique identifier: NCT01098591.

Relationship Between Intravascular Ultrasound Guidance and Clinical Outcomes After Drug-Eluting Stents The Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents (ADAPT-DES) Study

Background— Prior small to modest-sized studies suggest a benefit of intravascular ultrasound (IVUS) guidance in noncomplex lesions. Whether IVUS guidance is associated with improved clinical outcomes after drug-eluting stent (DES) implantation in an unrestricted patient population is unknown. Methods and Results— Assessment of Dual Antiplatelet Therapy With Drug-Eluting Stents (ADAPT-DES) was a prospective, multicenter, nonrandomized “all-comers” study of 8583 consecutive patients at 11 international centers designed to determine the frequency, timing, and correlates of stent thrombosis and adverse clinical events after DES. Propensity-adjusted multivariable analysis was performed to examine the relationship between IVUS guidance and 1-year outcomes. IVUS was utilized in 3349 patients (39%), and larger-diameter devices, longer stents, and/or higher inflation pressures were used in 74% of IVUS-guided cases. IVUS guidance compared with angiography guidance was associated with reduced 1-year rates of definite/probable stent thrombosis (0.6% [18 events] versus 1.0% [53 events]; adjusted hazard radio, 0.40; 95% confidence interval, 0.21–0.73; P=0.003), myocardial infarction (2.5% versus 3.7%; adjusted hazard radio, 0.66; 95% confidence interval, 0.49–0.88; P=0.004), and composite adjudicated major adverse cardiac events (ie, cardiac death, myocardial infarction, or stent thrombosis) (3.1% versus 4.7%; adjusted hazard radio, 0.70; 95% confidence interval, 0.55–0.88; P=0.002). The benefits of IVUS were especially evident in patients with acute coronary syndromes and complex lesions, although significant reductions in major adverse cardiac events were present in all patient subgroups those with including stable angina and single-vessel disease. Conclusions— In ADAPT-DES, the largest study of IVUS use to date, IVUS guidance was associated with a reduction in stent thrombosis, myocardial infarction, and major adverse cardiac events within 1 year after DES implantation. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00638794.

Therapeutic Hypothermia After Out-of-Hospital Cardiac Arrest Evaluation of a Regional System to Increase Access to Cooling

Background— Therapeutic hypothermia (TH) improves survival and confers neuroprotection in out-of-hospital cardiac arrest (OHCA), but TH is underutilized, and regional systems of care for OHCA that include TH are needed. Methods and Results— The Cool It protocol has established TH as the standard of care for OHCA across a regional network of hospitals transferring patients to a central TH-capable hospital. Between February 2006 and August 2009, 140 OHCA patients who remained unresponsive after return of spontaneous circulation were cooled and rewarmed with the use of an automated, noninvasive cooling device. Three quarters of the patients (n=107) were transferred to the TH-capable hospital from referring network hospitals. Positive neurological outcome was defined as Cerebral Performance Category 1 or 2 at discharge. Patients with non–ventricular fibrillation arrest or cardiogenic shock were included, and patients with concurrent ST-segment elevation myocardial infarction (n=68) received cardiac intervention and cooling simultaneously. Overall survival to hospital discharge was 56%, and 92% of survivors were discharged with a positive neurological outcome. Survival was similar in transferred and nontransferred patients. Non–ventricular fibrillation arrest and presence of cardiogenic shock were associated strongly with mortality, but survivors with these event characteristics had high rates of positive neurological recovery (100% and 89%, respectively). A 20% increase in the risk of death (95% confidence interval, 4% to 39%) was observed for every hour of delay to initiation of cooling. Conclusions— A comprehensive TH protocol can be integrated into a regional ST-segment elevation myocardial infarction network and achieves broad dispersion of this essential therapy for OHCA.Background— Therapeutic hypothermia (TH) improves survival and confers neuroprotection in out-of-hospital cardiac arrest (OHCA), but TH is underutilized, and regional systems of care for OHCA that include TH are needed. Methods and Results— The Cool It protocol has established TH as the standard of care for OHCA across a regional network of hospitals transferring patients to a central TH-capable hospital. Between February 2006 and August 2009, 140 OHCA patients who remained unresponsive after return of spontaneous circulation were cooled and rewarmed with the use of an automated, noninvasive cooling device. Three quarters of the patients (n=107) were transferred to the TH-capable hospital from referring network hospitals. Positive neurological outcome was defined as Cerebral Performance Category 1 or 2 at discharge. Patients with non–ventricular fibrillation arrest or cardiogenic shock were included, and patients with concurrent ST-segment elevation myocardial infarction (n=68) received cardiac intervention and cooling simultaneously. Overall survival to hospital discharge was 56%, and 92% of survivors were discharged with a positive neurological outcome. Survival was similar in transferred and nontransferred patients. Non–ventricular fibrillation arrest and presence of cardiogenic shock were associated strongly with mortality, but survivors with these event characteristics had high rates of positive neurological recovery (100% and 89%, respectively). A 20% increase in the risk of death (95% confidence interval, 4% to 39%) was observed for every hour of delay to initiation of cooling. Conclusions— A comprehensive TH protocol can be integrated into a regional ST-segment elevation myocardial infarction network and achieves broad dispersion of this essential therapy for OHCA. # Clinical Perspective {#article-title-40}

Extracellular Proteases in Atherosclerosis and Restenosis

Extracellular proteolysis plays a key role in many pathophysiologic processes including cancer, inflammatory diseases, and cardiovascular conditions such as atherosclerosis and restenosis. Whereas matrix metalloproteinases are their best known member, many others are becoming better known. The extracellular proteases are a complex and heterogeneous superfamily of enzymes. They include metalloproteinases (matrix metalloproteinases, adamalysins, or pappalysins), serine proteases (elastase, coagulation factors, plasmin, tissue plasminogen activator, urokinase plasminogen activator), and the cysteine proteases (such cathepsins). In addition to their matrix degradation capabilities, they have other less well known biologic functions that include angiogenesis, growth factor bioavailability, cytokine modulation, receptor shedding, enhancing cell migration, proliferation, invasion, and apoptosis. This review discusses extracellular proteases relevant to the vasculature, their classification and function, and how protease disorders contribute to arterial plaque growth, including chronic atherosclerosis, acute coronary syndromes, restenosis, and vascular remodeling. These broad extracellular protease functions make them potentially interesting therapeutic targets.

Benefit of Transferring ST-Segment–Elevation Myocardial Infarction Patients for Percutaneous Coronary Intervention Compared With Administration of Onsite Fibrinolytic Declines as Delays Increase

Background— Although randomized trials suggest that transfer for primary percutaneous coronary intervention (X-PCI) in ST-segment–elevation myocardial infarction is superior to onsite fibrinolytic therapy (O-FT), the generalizability of these findings to routine clinical practice is unclear because door-to-balloon (XDB) times are rapid in randomized trials but are frequently prolonged in practice. We hypothesized that delays resulting from transfer would reduce the survival advantage of X-PCI compared with O-FT. Methods and Results— ST-segment–elevation myocardial infarction patients enrolled in the National Registry of Myocardial Infarction (NRMI) within 12 hours of pain onset were identified. Propensity matching of patients treated with X-PCI and O-FT was performed, and the effect of PCI-related delay on in-hospital mortality was assessed. PCI-related delay was calculated by subtracting the XDB from the door-to-needle time in each matched pair. Conditional logistic regression adjusted for patient and hospital variables identified the XDB door-to-needle time at which no mortality advantage for X-PCI over O-FT was present. Eighty-one percent of X-PCI patients were matched (n=9506) to O-FT patients (n=9506). In the matched cohort, X-PCI was performed with delays >90 minutes in 68%. Multivariable analysis found no mortality advantage for X-PCI over O-FT when XDB door-to-needle time exceeded ≈120 minutes. Conclusion— PCI-related delays are extensive among patients transferred for X-PCI and are associated with poorer outcomes. No differential excess in mortality was seen with X-PCI compared with O-FT even with long PCI-related delays, but as XDB door-to-needle time times increase, the mortality advantage for X-PCI over O-FT declines.