Erminia M. Guarneri

Catheter-Based Radiotherapy to Inhibit Restenosis after Coronary Stenting

BACKGROUND In animal models of coronary restenosis, intracoronary radiotherapy has been shown to reduce the intimal hyperplasia that is a part of restenosis. We studied the safety and efficacy of catheter-based intracoronary gamma radiation plus stenting to reduce coronary restenosis in patients with previous restenosis. METHODS Patients with restenosis underwent coronary stenting, as required, and balloon dilation and were then randomly assigned to receive catheter-based irradiation with iridium-192 or placebo. Clinical follow-up was performed, with quantitative coronary angiographic and intravascular ultrasonographic measurements at six months. RESULTS Fifty-five patients were enrolled; 26 were assigned to the iridium-192 group and 29 to the placebo group. Angiographic studies were performed in 53 patients (96 percent) at a mean (+/-SD) of 6.7+/-2.2 months. The mean minimal luminal diameter at follow-up was larger in the iridium-192 group than in the placebo group (2.43+/-0.78 mm vs. 1.85+/-0.89 mm, P=0.02). Late luminal loss was significantly lower in the iridium-192 group than in the placebo group (0.38+/-1.06 mm vs. 1.03+/-0.97 mm, P=0.03). Angiographically identified restenosis (stenosis of 50 percent or more of the luminal diameter at follow-up) occurred in 17 percent of the patients in the iridium-192 group, as compared with 54 percent of those in the placebo group (P= 0.01). There were no apparent complications of the treatment. CONCLUSIONS In this preliminary, short-term study of patients with previous coronary restenosis, coronary stenting followed by catheter-based intracoronary radiotherapy substantially reduced the rate of subsequent restenosis.

Three-year clinical and angiographic follow-up after intracoronary radiation : results of a randomized clinical trial.

BACKGROUND Although several early trials indicate treatment of restenosis with radiation therapy is safe and effective, the long-term impact of this new technology has been questioned. The objective of this report is to document angiographic and clinical outcome 3 years after treatment of restenotic stented coronary arteries with catheter-based (192)Ir. METHODS AND RESULTS A double-blind, randomized trial compared (192)Ir with placebo sources in patients with previous restenosis after coronary angioplasty. Over a 9-month period, 55 patients were enrolled; 26 were randomized to (192)Ir and 29 to placebo. At 3-year follow-up, target-lesion revascularization was significantly lower in the (192)Ir group (15. 4% versus 48.3%; P<0.01). The dichotomous restenosis rate at 3-year follow-up was also significantly lower in (192)Ir patients (33% versus 64%; P<0.05). In a subgroup of patients with 3-year angiographic follow-up not subjected to target-lesion revascularization by the 6-month angiogram, the mean minimal luminal diameter between 6 months and 3 years decreased from 2.49+/-0.81 to 2.12+/-0.73 mm in (192)Ir patients but was unchanged in placebo patients. CONCLUSIONS The early clinical benefits observed after treatment of coronary restenosis with (192)Ir appear durable at late follow-up. Angiographic restenosis continues to be significantly reduced in (192)Ir-treated patients, but a small amount of late loss was observed between the 6-month and 3-year follow-up time points. No events occurred in the (192)Ir group to suggest major untoward effects of vascular radiotherapy. At 3-year follow-up, vascular radiotherapy continues to be a promising new treatment for restenosis.

Patient management after noninvasive cardiac imaging: Results from SPARC (Study of myocardial perfusion and coronary anatomy imaging roles in coronary artery disease)

OBJECTIVES This study examined short-term cardiac catheterization rates and medication changes after cardiac imaging. BACKGROUND Noninvasive cardiac imaging is widely used in coronary artery disease, but its effects on subsequent patient management are unclear. METHODS We assessed the 90-day post-test rates of catheterization and medication changes in a prospective registry of 1,703 patients without a documented history of coronary artery disease and an intermediate to high likelihood of coronary artery disease undergoing cardiac single-photon emission computed tomography, positron emission tomography, or 64-slice coronary computed tomography angiography. RESULTS Baseline medication use was relatively infrequent. At 90 days, 9.6% of patients underwent catheterization. The rates of catheterization and medication changes increased in proportion to test abnormality findings. Among patients with the most severe test result findings, 38% to 61% were not referred to catheterization, 20% to 30% were not receiving aspirin, 35% to 44% were not receiving a beta-blocker, and 20% to 25% were not receiving a lipid-lowering agent at 90 days after the index test. Risk-adjusted analyses revealed that compared with stress single-photon emission computed tomography or positron emission tomography, changes in aspirin and lipid-lowering agent use was greater after computed tomography angiography, as was the 90-day catheterization referral rate in the setting of normal/nonobstructive and mildly abnormal test results. CONCLUSIONS Overall, noninvasive testing had only a modest impact on clinical management of patients referred for clinical testing. Although post-imaging use of cardiac catheterization and medical therapy increased in proportion to the degree of abnormality findings, the frequency of catheterization and medication change suggests possible undertreatment of higher risk patients. Patients were more likely to undergo cardiac catheterization after computed tomography angiography than after single-photon emission computed tomography or positron emission tomography after normal/nonobstructive and mildly abnormal study findings. (Study of Perfusion and Anatomys Role in Coronary Artery [CAD] [SPARC]; NCT00321399).

Five-Year Clinical Follow-Up After Intracoronary Radiation Results of a Randomized Clinical Trial

Background—Several clinical trials indicate that intracoronary radiation is safe and effective for treatment of restenotic coronary arteries. We previously reported 6-month and 3-year clinical and angiographic follow-up demonstrating significant decreases in target lesion revascularization (TLR) and angiographic restenosis after &ggr; radiation of restenotic lesions. The objective of this study was to document the clinical outcome 5 years after treatment of restenotic coronary arteries with catheter-based iridium-192 (192Ir). Methods and Results—A double-blind, randomized trail compared 192Ir to placebo sources in patients with restenosis after coronary angioplasty. Over a 9-month period, 55 patients were enrolled; 26 were randomized to 192Ir and 29 to placebo. At 5-year follow-up, TLR was significantly lower in the 192Ir group (23.1% versus 48.3%;P =0.05). There were 2 TLRs between years 3 and 5 in patients in the 192Ir group and none in patients in the placebo group. The 5-year event-free survival rate (freedom from death, myocardial infarction, or TLR) was greater in 192Ir-treated patients (61.5% versus 34.5%;P =0.02). Conclusions—Despite apparent mitigation of efficacy over time, there remains a significant reduction in TLR at 5 years and an improvement in event-free survival in patients treated with intracoronary 192Ir. The early clinical benefits after intracoronary &ggr; radiation with 192Ir seem durable at 5-year clinical follow-up.

Two-Year Follow-Up After Catheter-Based Radiotherapy to Inhibit Coronary Restenosis

BACKGROUND Although early trials indicate the treatment of restenosis with radiation therapy is safe and effective, the long-term impact of this new technology has been questioned. The possibility of late untoward consequences, such as aneurysm formation, perforation, and accelerated vascular disease, is of significant concern. Furthermore, it is not known whether the beneficial effects of radiation therapy will be durable or whether radiation will only delay restenosis. METHODS AND RESULTS A double-blind, randomized trial was undertaken to compare 192Ir with placebo sources in patients with previous restenosis after coronary angioplasty. Patients were randomly assigned to receive a 0.76-mm (0. 03-in) ribbon containing sealed sources of either 192Ir or placebo. All patients underwent repeat coronary angiography at 6 months. All living patients were contacted 24 months after their index study procedure. Patients were assessed with respect to the need for target-lesion revascularization or nontarget-lesion revascularization, occurrence of myocardial infarction, or death. Over a 9-month period, 55 patients were enrolled; 26 were randomized to 192Ir and 29 to placebo. Follow-up was obtained in 100% of living patients at a minimum of 24 months. Target-lesion revascularization was significantly lower in the 192Ir group (15.4% versus 44.8%; P<0. 01). Nontarget-lesion revascularization was similar in 192Ir and placebo patients (19.2% versus 20.7%; P=NS). There were 2 deaths in each group. The composite end point of death, myocardial infarction, or target-lesion revascularization was significantly lower in 192Ir-treated versus placebo-treated patients (23.1% versus 51.7%; P=0.03). No patient in the 192Ir group sustained a target-lesion revascularization later than 10 months. CONCLUSIONS At 2-year clinical follow-up, treatment with 192Ir demonstrates significant clinical benefit. Although further follow-up (including late angiography) will be necessary, no clinical events have occurred to date in the 192Ir group to suggest major untoward effects of vascular radiotherapy. At the intermediate follow-up time point, vascular radiotherapy continues to be a promising new treatment for restenosis.

A subgroup analysis of the scripps coronary radiation to inhibit proliferation poststenting trial

INTRODUCTION In the Scripps Coronary Radiation to Inhibit Proliferation Poststenting (SCRIPPS) Trial, 192Ir significantly reduced angiographic, ultrasonographic, and clinical endpoints of restenosis. The objective of this analysis was to quantitate the impact of patient, lesion and technical characteristics on late angiographic outcome. METHODS Patients with restenotic, stented coronary lesions were randomized to receive either 192Ir or placebo sources. Late luminal loss and loss index were calculated for several patient subgroups, including patients with diabetes, in-stent restenosis, multiple previous percutaneous transluminal coronary angioplasty (PTCA) procedures, longer lesion lengths, saphenous vein grafts, small vessel diameters, and minimum dose exposures < 8.00 Gy. Two-factor analysis of variance was used to test for an interaction between patient characteristics and treatment effect. RESULTS In the treated group, late loss was particularly low in patients with diabetes (0.19 mm), in-stent restenosis (0.17 mm), reference vessel diameters < 3.0 mm (0.07 mm), and patients who received a minimum radiation dose to the entire adventitial border of at least 8.00 Gy. The loss index in each of these subgroups was similarly low at -0.02, 0.03, -0.02, and 0.03, respectively. By 2-factor analysis of variance, a significant interaction between subgroup characteristic and treatment effect (late loss) was found in patients with in-stent restenosis (p = 0.035), and patients receiving a minimum dose of 8.00 Gy to the adventitial border (p = 0.009). CONCLUSION In this pilot study, patient characteristics associated with a more aggressive proliferative response to injury appeared to confer an enhanced response to radiotherapy. Furthermore, a dose threshold response to 192Ir was found with an enhanced response occurring when the entire circumference of the adventitial border was exposed to at least 8.00 Gy.

Healing Touch With Guided Imagery for PTSD in Returning Active Duty Military: A Randomized Controlled Trial

Post-traumatic stress disorder (PTSD) remains a significant problem in returning military and warrants swift and effective treatment. We conducted a randomized controlled trial to determine whether a complementary medicine intervention (Healing Touch with Guided Imagery [HT+GI]) reduced PTSD symptoms as compared to treatment as usual (TAU) returning combat-exposed active duty military with significant PTSD symptoms. Active duty military (n = 123) were randomized to 6 sessions (within 3 weeks) of HT+GI vs. TAU. The primary outcome was PTSD symptoms; secondary outcomes were depression, quality of life, and hostility. Repeated measures analysis of covariance with intent-to-treat analyses revealed statistically and clinically significant reduction in PTSD symptoms (p < 0.0005, Cohens d = 0.85) as well as depression (p < 0.0005, Cohens d = 0.70) for HT+GI vs. TAU. HT+GI also showed significant improvements in mental quality of life (p = 0.002, Cohens d = 0.58) and cynicism (p = 0.001, Cohens d = 0.49) vs. TAU. Participation in a complementary medicine intervention resulted in a clinically significant reduction in PTSD and related symptoms in a returning, combat-exposed active duty military population. Further investigation of GT and biofield therapy approaches for mitigating PTSD in military populations is warranted.

Differences in TIMI frame count following successful reperfusion with stenting or percutaneous transluminal coronary angioplasty for acute Myocardial Infarction

The Thrombolysis In Myocardial Infarction (TIMI) flow grade achieved in the infarct-related artery (IRA) during reperfusion therapy for acute myocardial infarction (AMI) is directly related to myocardial salvage. Recently, several series have demonstrated the safety of stenting in AMI and documented a larger postprocedure luminal diameter than that found at angioplasty, although no study has compared the effect of PTCA and stenting in AMI on flow characteristics of the IRA. The residual stenosis and the number of frames required to opacify standardized angiographic landmarks normalized for vessel length (corrected TIMI frame count) or compared with flow in a corresponding normal coronary artery (TIMI frame count index) were determined for the IRA of 39 patients who underwent angioplasty or stenting for AMI. Baseline characteristics were similar for the 20 patients who underwent stenting and the 19 patients who underwent percutaneous transluminal coronary angioplasty. After intervention, the luminal diameter was greater (3.24 vs 2.09 mm, p <0.0001) and the residual stenosis was less (-9.4% vs. 26.7%, p <0.0001) after stenting than after percutaneous transluminal coronary angioplasty. These changes in vessel geometry were associated with a lower corrected TIMI frame count (16.1 vs 30.7, p <0.002) and a lower TIMI frame count index (0.68 vs 1.3, p <0.002). Thus, stenting in AMI is associated with a greater postprocedure luminal diameter and improvement in coronary blood flow as measured by the TIMI frame count method.

Niacin: chemical forms, bioavailability, and health effects

Elevated low-density lipoprotein cholesterol (LDL-C) has been the main target of lipid-altering therapy to reduce cardiovascular risk associated with dyslipidemia. Residual cardiovascular risk remains, however, after achievement of goal LDL-C levels and is associated in part with other risk markers of cardiovascular disease, including low high-density lipoprotein cholesterol (HDL-C), high lipoprotein a, and hypertriglyceridemia. Niacin is considered a valuable agent for therapy to modify high LDL-C as well as low HDL-C, high lipoprotein a, and hypertriglyceridemia. The forms of niacin available in the marketplace include unbound niacin, or free nicotinic acid (NA); extended-release NA, a form of NA that is released gradually over a period of time; inositol hexanicotinate, six molecules of NA covalently bonded to one molecule of inositol; and nicotinamide, or niacinamide, the amide form of NA, which is readily bioavailable. This review is designed to assist healthcare professionals in evaluating the form(s) of niacin best suited for a particular therapeutic goal. Further, it provides a literature-based evaluation of risk for NA, extended-release NA, inositol hexanicotinate, and nicotinamide.

Endovascular brachytherapy to inhibit coronary artery restenosis: An introduction to the scripps coronary radiation to inhibit proliferation post stenting trial

This year is the 100th anniversary of the use of ionizing radiation to treat disease. Since the turn of the century, many benign and malignant diseases have been treated with radiation therapy (RT). Through the decades, however, the application of RT in the treatment of benign diseases has largely disappeared-supplanted by other medical or surgical therapies. RT has most recently been committed to the treatment of malignancies to such a degree that the specialty was renamed radiation oncology. However, a continued. though very limited, role for RT has persisted in the treatment of certain benign hyperplastic disorders. RT significantly inhibits excessive fibroblast activity. Judicious clinical use of low-dose RT is highly effective in inhibiting such benign conditions as conjunctival pterygia. keloid scars. and aggressive fibromatosis. Excessive bone formation by the osteoblast, a derivative of the fibroblast. is successfully inhibited by low-dose RT and thereby inhibits heterotopic ossification. Although such benign hyperplasia disorders are significant clinical entities, the main thrust of RT continues to be the treatment of malignancies. With the coming millennium, a new therapeutic application of RT in benign disease promises to open new vistas previously unimagined. Studies have just begun in using RT to prevent vascular restenosis. RT may provide a powerful tool to solve what has become a vexing problem in vascular disease. In this review, we shall discuss early preclinical evidence that endovascular brachytherapy may inhibit coronary artery restenosis. We shall also introduce and describe the Scripps Clinic’s ongoing trial of endovascular RT in the prevention of coronary artery restenosis. The Scripps Coronary Radiation to Inhibit Proliferation Post Stenting trial (SCRIPPS) is the first attempt to use catheter-based intracoronary ionizing radiation in a prospective double-blinded randomized study. The study’s objective is to determine the initial safety and efficacy in reversing and preventing coronary artery restenosis by adding lowdose RT to today’s optima1 conventional cardiovascular therapy. This review will hopefully also provide a basis to understand the rationale and some of the potential benefits of applying radiation in the treatment of coronary artery restenosis.