Stephen W. Waldo
University of Colorado Denver
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Featured researches published by Stephen W. Waldo.
Vascular Health and Risk Management | 2016
Vikas Aggarwal; Stephen W. Waldo; Ehrin J. Armstrong
Atherosclerotic iliac artery disease is increasingly being treated with endovascular techniques. A number of new stent technologies can be utilized with high long-term patency, including self-expanding stents, balloon-expandable stents, and covered stents, but comparative data on these stent types and in more complex lesions are lacking. This article provides a review of currently available iliac stent technologies, as well as complex procedural aspects of iliac artery interventions, including approaches to the treatment of iliac bifurcation disease, long segment occlusions, choice of stent type, and treatment of iliac artery in-stent restenosis.
Catheterization and Cardiovascular Interventions | 2017
T. Raymond Foley; Ryan Cotter; Damianos G. Kokkinidis; Daniel D. Nguyen; Stephen W. Waldo; Ehrin J. Armstrong
To assess the intraprocedural and mid‐term outcomes of orbital atherectomy (OA) combined with drug‐coated balloon (DCB) angioplasty for the treatment of calcified femoropopliteal disease.
Expert Review of Cardiovascular Therapy | 2017
Damianos G. Kokkinidis; Stephen W. Waldo; Ehrin J. Armstrong
ABSTRACT Introduction: Although drug-eluting stents (DES) have significantly reduced the incidence and prevalence of coronary in-stent restenosis (ISR), ISR still occurs in approximately 10% of patients in real-world practice. Areas covered: The development of newer generations of DES, drug-coated balloons (DCB) and increased use of intracoronary imaging have improved our treatment options for and pathophysiologic understanding of ISR. These technological advancements have also largely supplanted older modalities for treatment of ISR, such as brachytherapy, bare metal stents, conventional and cutting balloon angioplasty, and atherectomy devices. This article reviews the presentation, pathophysiology, and treatment of coronary artery ISR, with a focus on recent clinical data and emerging therapies for this difficult to treat clinical problem. Expert commentary: DCB and second-generation DES are the most effective treatment options for ISR. Most trials support a slight superiority of second-generation DES, while DCB have the advantage of not adding another metal layer. The role of bioresorbable vascular scaffolds will be determined in the near future.
Vascular Medicine | 2016
T. Raymond Foley; Stephen W. Waldo; Ehrin J. Armstrong
Antiplatelet agents are recommended for the reduction of major adverse cardiovascular events among all patients with symptomatic peripheral artery disease. However, the optimal antiplatelet regimen and duration of therapy in peripheral artery disease (PAD) remains unclear, largely due to limited and conflicting data in this patient population. This article reviews current data on antithrombotic therapy in PAD and discusses the implications of this data for current practice and future research.
Heart | 2016
T Raymond Foley; Ehrin J. Armstrong; Stephen W. Waldo
Peripheral artery disease (PAD) includes atherosclerosis of the aorta and lower extremities. Affecting a large segment of the population, PAD is associated with impaired functional capacity and reduced quality of life as well as an increased risk of stroke, myocardial infarction and cardiovascular death. The evaluation of PAD begins with the physical examination, incorporating non-invasive testing such as ankle-brachial indices to confirm the diagnosis. Therapeutic interventions are aimed at alleviating symptoms while preserving limb integrity and reducing overall cardiovascular risk. With this in mind, risk factor modification with exercise and medical therapy are the mainstays of treatment for many patients with PAD. Persistent symptoms or non-healing wounds should prompt more aggressive therapies with endovascular or surgical revascularisation. The following manuscript provides a comprehensive review on the contemporary evaluation and management of PAD.
Journal of the American Heart Association | 2017
T. Raymond Foley; Gagan D. Singh; Damianos G. Kokkinidis; Ho Hin K. Choy; Thai Pham; Ezra A. Amsterdam; John C. Rutledge; Stephen W. Waldo; Ehrin J. Armstrong; John R. Laird
Background The relative benefit of higher statin dosing in patients with peripheral artery disease has not been reported previously. We compared the effectiveness of low‐ or moderate‐intensity (LMI) versus high‐intensity (HI) statin dose on clinical outcomes in patients with peripheral artery disease. Methods and Results We reviewed patients with symptomatic peripheral artery disease who underwent peripheral angiography and/or endovascular intervention from 2006 to 2013 who were not taking other lipid‐lowering medications. HI statin use was defined as atorvastatin 40–80 mg or rosuvastatin 20–40 mg. Baseline demographics, procedural data, and outcomes were retrospectively analyzed. Among 909 patients, 629 (69%) were prescribed statins, and 124 (13.6%) were treated with HI statin therapy. Mean low‐density lipoprotein level was similar in patients on LMI versus HI (80±30 versus 87±44 mg/dL, P=0.14). Demographics including age (68±12 versus 67±10 years, P=0.25), smoking history (76% versus 80%, P=0.42), diabetes mellitus (54% versus 48%, P=0.17), and hypertension (88% versus 89%, P=0.78) were similar between groups (LMI versus HI). There was a higher prevalence of coronary artery disease (56% versus 75%, P=0.0001) among patients on HI statin (versus LMI). After propensity weighting, HI statin therapy was associated with improved survival (hazard ratio for mortality: 0.52; 95% confidence interval, 0.33–0.81; P=0.004) and decreased major adverse cardiovascular events (hazard ratio: 0.58; 95% confidence interval 0.37–0.92, P=0.02). Conclusions In patients with peripheral artery disease who were referred for peripheral angiography or endovascular intervention, HI statin therapy was associated with improved survival and fewer major adverse cardiovascular events compared with LMI statin therapy.
Journal of Endovascular Therapy | 2018
Damianos G. Kokkinidis; Prio Hossain; Omar Jawaid; Bejan Alvandi; T. Raymond Foley; Gagan D. Singh; Stephen W. Waldo; John R. Laird; Ehrin J. Armstrong
Purpose: To examine whether laser atherectomy combined with drug-coated balloons (laser + DCB) can improve the outcomes of femoropopliteal (FP) in-stent restenosis (ISR). Methods: A dual-center retrospective study was conducted of 112 consecutive patients (mean age 70.3±10.6 years; 86 men) with Tosaka class II (n=29; diffuse stenosis) or III (n=83; occlusion) FP-ISR lesions. Sixty-two patients (mean age 68.5±10 years; 51 men) underwent laser + DCB while the other 50 patients (mean age 72.5±10.8 years; 35 men) had laser atherectomy plus balloon angioplasty (laser + BA). Critical limb ischemia was the indication in 33% of the interventions. The average lesion length was 247 mm. A Cox regression hazard model was developed to examine the association between laser + DCB vs laser + BA; the results are presented as the hazard ratio (HR) and 95% confidence interval (CI). One-year target lesion revascularization (TLR) and reocclusion were estimated using the Kaplan-Meier method. Results: Overall procedure success was 98% and was similar between groups. Bailout stenting was less often required in the laser + DCB group (31.7% vs 58%, p=0.006). The combination of laser + DCB was associated with improved 12-month estimates for freedom from TLR (72.5% vs 50.5%, p=0.043) and freedom from reocclusion (86.7% vs 56.9%, p=0.003). Among patients with Tosaka III FP-ISR, combination therapy with laser + DCB was also associated with increased freedom from reocclusion (87.1% vs 57.1%, p=0. 028). On multivariable analysis, treatment with laser + DCB was associated with a significantly reduced risk of reocclusion (HR 0.08, 95% CI 0.17 to 0.38; p=0.002). Conclusion: When used for treatment of complex FP-ISR lesions, DCB angioplasty combined with laser atherectomy is associated with significantly reduced 1-year TLR and reocclusion rates.
Current Cardiology Reports | 2016
Ehrin J. Armstrong; Kalkidan Bishu; Stephen W. Waldo
Endovascular treatment of infrapopliteal disease is focused on the treatment of patients with rest pain or critical limb ischemia (CLI) due to severe atherosclerotic disease. While the evidence base surrounding the comparative effectiveness of endovascular intervention vs. surgery is lacking, many operators have adopted an “endovascular first” approach to the treatment of infrapopliteal atherosclerotic disease due to the lower morbidity of these procedures. This manuscript reviews current data on the endovascular treatment of CLI, including a comparison of endovascular and surgical approaches, current indications for and outcomes with balloon angioplasty of infrapopliteal PAD, angiosome-guided revascularization, and emerging technologies to improve long-term vessel patency after endovascular intervention.
Catheterization and Cardiovascular Interventions | 2018
Damianos G. Kokkinidis; Andrew F. Prouse; Seth Avner; Joo Myung Lee; Stephen W. Waldo; Ehrin J. Armstrong
The benefit of drug‐eluting stents (DES) versus drug‐coated balloons (DCB) in coronary artery in‐stent restenosis (ISR) for the prevention of target lesion revascularization (TLR), stent thrombosis, and mortality remains uncertain. Our aim was to synthesize the available evidence from randomized clinical trials (RCTs) and observational studies that directly compare second‐generation drug‐eluting stents (SG‐DES) and DCB for the treatment of coronary ISR.
Interventional cardiology clinics | 2016
Dominik M. Wiktor; Stephen W. Waldo; Ehrin J. Armstrong
Current-generation coronary drug-eluting stents are associated with low rates of restenosis and target lesion revascularization. However, several mechanisms of stent failure remain clinically important. Stent fracture may occur in areas of excessive torsion or angulation. Longitudinal stent deformation is related to axial stent compression owing to extrinsic forces or secondary devices that disrupt stent architecture. Stent recoil occurs when a stent does not deploy at its optimal cross-sectional area. Tissue prolapse between stent struts may also predispose patients to adverse outcomes. Prevention, recognition, and treatment of these stent failures are necessary to optimize patient outcomes after percutaneous coronary interventions.