Cost-effectiveness Analysis of Intravascular Ultrasound Guided Percutaneous Coronary Intervention versus Conventional Percutaneous Coronary Intervention

Objective - Investigation of the cost-effectiveness of intravascular ultrasound (IVUS) guided percutaneous coronary intervention (PCI) compared to PCI guided by coronary angiography (CAG). Methods - One hundred and eight men referred for PCI, were randomized to IVUS or CAG guided PCI. After 6 months, the patients were subjected to a study related clinical and invasive follow-up investigation by CAG, IVUS and intracoronary Doppler flow measurements. Incremental costs of IVUS guided procedures and costs of reinterventions were estimated using the Activity Based Costing (ABC) method. Results - Patients randomized to IVUS guided PCI experienced an improved clinical outcome, with lower angina levels than patients in the CAG guided group. The initial cost of performing IVUS guidance was increased due to extra procedure time, IVUS catheters and slightly more balloons and stents, but fewer patients in the IVUS guided group needed re-intervention. Overall, these savings outweighed the initial cost increase. Conclusion - Our data suggest that when performing IVUS guided PCI, costs as well as benefits increase. The increased benefits measured as cost savings resulting from less restenosis outweigh the cost increase from performing the IVUS guided PCI as opposed to CAG guided PCI.     

Predictors of Restenosis after Coronary Angioplasty. A Study on Demographic and Metabolic Variables

Objective - The major concern about percutaneous transluminal coronary angioplasty (PTCA) is the high incidence of restenosis. Methods - Demographic, clinical and biochemical data were recorded 2 weeks prior to PTCA in 388 patients fulfilling the criteria for initial stenosis, successful PTCA, and angiographic follow-up after 6 months. Restenosis was evaluated by quantitative coronary angiography. Results - Variables predictive of restenosis in univariate analysis were diabetes mellitus, male gender, and the levels of high density lipoprotein (HDL) cholesterol, apolipoprotein A1 (Apo A1) and thio-barbituric acid-reactive substances (TBARS). In trend analysis through quartiles TBARS and fasting glucose levels were significantly associated with restenosis (p = 0.016 and 0.044, respectively), whereas the negative predictivity of Apo A1 and HDL-cholesterol were of borderline significance. In multivariate analysis male gender and diabetes mellitus showed predictivity of significance, and a negative predictivity was also apparent for HDL-cholesterol. Conclusion - We conclude that diabetes mellitus, male gender, and low HDL-cholesterol are predictors of restenosis 6 months after PTCA. In addition, TBARS may be a marker for the development of restenosis after PTCA.     

Assessment of Myocardium at Risk with Computerized Vectorcardiography and Technetium-99m-Sestamibi-Single Photon Emission Computed Tomography during Coronary Angioplasty

Objective - To compare the myocardium at risk (MAR) as estimated by computerized vectorcardiography (cVCG) with MAR determined by Tc-99m-sestamibi-SPECT using coronary angioplasty as the model for transient transmural ischemia in humans. Methods and results - In 37 patients with stable angina pectoris, cVCG was recorded continuously during coronary angioplasty. The scintigraphic defect was quantified using an automated software program (CEqual). The ST vector magnitude (ST-VM) and the ST change vector magnitude (STC-VM) correlated well with MAR estimated by scintigraphy, ST-VM ( r = 0.71, p < 0.001) and STC-VM ( r = 0.84, p < 0.001). All patients with STC-VM <50 &#119 V during occlusion had defects of less than 10% of the left ventricle. Conclusion - 1) ST-VM and STC-VM give a reasonable useful estimate of MAR size during transient coronary occlusion. 2) STC-VM <50 &#119 V is a reliable limit to identify patients with MAR size less than 10%. 3) ST-VM does not add information to STC-VM with respect to detection of ischemia. 4) The existence of collateral vessels has great impact on both ST-vector changes and scintigraphic imaging of myocardial ischemia.     

Routine Use of Intravascular Ultrasound for Endovascular Aneurysm Repair: Angiography is not Necessary

INTRODUCTION: to assess the outcome of endovascular aortic aneurysm repair (EVAR) using intravascular ultrasound (IVUS) without angiography. MATERIALS/METHODS: eighty consecutive patients (median age 69 years (range 25-90): male 72 (90%), female 8 (10%)) underwent endovascular aneurysm repair (AAA 68 (85%), TAA 12 (15%)) using either angiography in 31/80 patients (39%) or IVUS in 49/80 patients (61%) in accordance to the surgeons preference. RESULTS: hospital mortality was 2/80 (3%), 1/68 for AAA (2%), 1/12 for TAA (8%), 2/31 for angiography (7%), and 0/49 for IVUS (0.0%: NS). Median quantity of contrast medium was 190 ml (range: 20-350) for angiography versus 0 ml for IVUS (p<0.01). Median X-ray exposure time 24 min (range 9-65 min) versus 8 min (range 0-60 min) for IVUS (p<0.05). No coverage of renal or suprarenal artery orifices occurred in either group. Conversion to open surgery was necessary in 4/80 patients (5%), 1/31 for angiography (3%) and 3/49 patients for IVUS (6%: NS). Early endoleaks were observed in 13/80 patients (16%): 8/31 patients for angiography (26%) versus 5/49 for IVUS (10%: p<0.05): 5/13 endoleaks resolved spontaneously (39%) whereas 8/13 (61%) required additional procedures. CONCLUSIONS: IVUS is a reliable tool for EVAR. In most cases, perprocedural angiography is not necessary.     

Long-Term Retention of A Novel Antioxidant Sulphur-substituted Fatty Acid Analogue After Local Delivery in Porcine Coronary Arteries

Objective: Antioxidants have been suggested to reduce restenosis after balloon angioplasty. A novel sulphurcontaining fatty acid, tetradecylthioacetic acid (TTA), with antioxidant properties, is efficiently incorporated into cellular phospholipids. We have determined the uptake and retention of TTA after local coronary artery delivery in 20 pigs. Design: Radiolabelled TTA was delivered to 40 main coronary arteries via a multiporous coronary angioplasty balloon catheter inflated before, after, or without overstretch vessel injury. The animals were killed at intervals of up to 6 weeks post-procedure. The radioactivity of the tissue sections was determined as nmol TTA/g tissue. Results:     

Intensive use of intravascular ultrasound during coronary angioplasty. A six-month campaign

BACKGROUND: Compared to coronary angiography, intravascular ultrasound (IVUS) gives additional information important for the percutaneous transluminal coronary angioplasty (PTCA) procedure, but is time-consuming and may cause complications. AIM: To evaluate, during a period of intensive use of IVUS, the impact of IVUS on the final decision on balloon/stent diameter, consumption of devices, time-consumption and IVUS-related complications. METHOD: During a 6-month period, IVUS was contemplated in all PTCA procedures and the reason for not using IVUS was specified. We used CVIS during the first, and Endosonics during the last 3 months, and both periods started with 1 week of hands-on practice. All procedures were to be planned according to an initial quantitative coronary angiography (QCA), and the finally achieved result, material used and complications were registered. RESULTS: The proportion of IVUS/PTCA was 37% during, 8% 6 months before and 12% 6 months after the study period. Three hundred and twenty-three patients were included in the study (57% of all patients), 199 of them were subjected to IVUS. The indications for PTCA during the study period were stable angina (58%), unstable angina (32%) and acute myocardial infarction (10%). The main reasons for not doing IVUS were use of 6F guiding catheter (13%), urgent procedure (12%) and occluded vessel (11%). Initial QCA detected 253 stenoses in 199 patients and 64 additional stenoses were treated, most of them probably detected by IVUS. QCA systematically underestimated vessel size, particularly in small vessels. There was a non-significant trend to more accurate estimations towards the end of the study in small vessels. Dissection, probably due to IVUS, occurred in two cases (1%). There were no significant differences in the number of devices used in IVUS compared to non-IVUS patients. The procedural time was 24 min longer in IVUS than in non-IVUS cases and more stenoses were treated per procedure in the IVUS group. CONCLUSION: Coronary angiography often underestimated balloon/stent size but in an unpredictable way, with a substantial proportion of significant stenoses being undetected. IVUS had few serious complications, did not increase device consumption but prolonged procedural time.     

Ultrasound Guided Human Thrombin Injection. A New Modality in the Management of Femoral Artery Pseudo-aneurysms

OBJECTIVES: We report our initial results of a prospective study of duplex ultrasound-guided injection (UGTI ) of thrombin in the management of femoral artery pseudo-aneurysms. We used human thrombin to avoid the increase in the human antibodies directed against fibrinogen, with the use of bovine thrombus, that preclude further utilisation of the bovine fibrin glue during cardio-thoracic surgery. METHODS: From 1999 to 2001, 19 patients, aged 69 (range 52-85) years presented with 21 femoral pseudo-aneurysms were treated. The mean pseudoaneurysm diameter was 30 (15-55) mm. All but two were secondary to cardiac procedures and the common femoral artery was the injured vessel in all instances. Patients were referred within 2-21 days following their iatrogenic injury. RESULTS: Immediate thrombosis of the sac occurred in 19 (90%) of the 21 pseudo-aneurysms. After a second injection, complete occlusion occurred in the remaining two patients. Two patients (CI 95%; 1-19) with three femoral pseudo-aneurysms developed leg pain. Duplex ultrasound follow-up showed two recurrences (9.5% - CI 95%; 1-19) and both were treated by repeat UGTI. There was no conversion to surgical repair. CONCLUSION: This percutaneous minimally invasive technique is safe and effective in the management of iatrogenic pseudo-aneurysms in this high-risk group of patients. Human thrombin has significant advantages over bovine thrombin.     

Use of the cell saver during elective abdominal aortic aneurysm surgery--influence on transfusion with bank blood. A retrospective survey.

One hundred and two patients undergoing elective abdominal aortic aneurysm repair and admitted to ICU at RPAH in 1989/90 were studied. In forty patients a cell saver was used during the operative procedure (Group CS) while in the remaining sixty-two patients intraoperative blood loss was drained and discarded conventionally (Group NCS). Preoperative ASA grade and postoperative APACHE score were similar in these two groups. The amount of bank blood transfused intraoperatively was less in Group CS than in Group NCS (0.6 +/- 0.2 vs 3.3 +/- 0.3 units) (mean +/- SEM) (P less than 0.0001). The total amount of bank blood transfused during hospital admission was also less in Group CS (1.5 +/- 0.4 vs 4.8 +/- 0.4 units, P less than 0.0001). Of Group CS, 22 patients (55%) received no bank blood compared to two patients (3%) in Group NCS. There was no difference between the groups with respect to postoperative haemoglobin and creatinine levels. ICU stay was similar in both groups. We conclude that use of the cell saver reduces perioperative bank blood transfusion in elective abdominal aortic surgery.     

Use of colony-stimulating factors (CSF) during chemotherapy of patients with testicular cancer. A comparison between G-CSF and GM-CSF

Colony-stimulating factors (CSF) are frequently used in cases of cytostatic therapy of patients with testicular cancer assuming that they support hematopoietic recovery and, thus, shorten duration of neutropenia as well as reduce infections. Currently, G-CSF and GM-CSF are clinically used. In the present study efficacy and toxicity of these two drugs were investigated and compared in patients with testicular cancer treated by standard chemotherapy. Studying 83 chemotherapy cycles applied to 31 patients with advanced germ cell tumors the effectivity and the side effects of the two CSF were examined by questioning, clinical evaluation, and blood chemistry studies. G-CSF (480 micrograms subcutaneously (s.c.)) were used in 55 and GM-CSF (400 micrograms s.c.) in 28 chemotherapeutic cycles. The indications consisted in the treatment of leukocytopenia on the one hand and in the prophylaxis in subsequent cycles on the other hand. No difference between the two CSF could be found either with regard to postponement of the next cycle (G-CSF: 6.8 vs. GM-CSF: 7.3 days), or to the number of injections per cycle (G-CSF: 8 vs. GM-CSF: 12.5), or to the leukocyte (G-CSF: 2.1 vs. GM-CSF: 1.6 x 10(3)/microliter) or platelet nadir (G-CSF: 0.5 vs. GM-CSF: 0.5 x 10(5)/microliter; mean values of all cycles, respectively). Both CSF did not seem to influence the production of platelets. However, a difference between the two CSF was demonstrated with respect to the toxicity. Frequency (G-CSF: 38.5% vs. GM-CSF: 69.3%) as well as intensity of side effects causing a change of the drug (G-CSF: n = 1 vs. GM-CSF: n = 7) were lower in the case of G-CSF. In conclusion, these data demonstrate no difference was seen between G-CSF and GM-CSF with respect to the efficacy in patients with testicular cancer treated by standard chemotherapy. However, the use of G-CSF seems to be associated with lower toxicity.     

Use of colony-stimulating factors (CSF) during chemotherapy of patients with testicular cancer. A comparison between G-CSF and GM-CSF A comparison between G-CSF and GM-CSF

Colony-stimulating factors (CSF) are frequently used in cases of cytostatic therapy of patients with testicular cancer assuming that they support hematopoietic recovery and, thus, shorten duration of neutropenia as well as reduce infections. Currently, G-CSF and GM-CSF are clinically used. In the present study efficacy and toxicity of these two drugs were investigated and compared in patients with testicular cancer treated by standard chemotherapy. Studying 83 chemotherapy cycles applied to 31 patients with advanced germ cell tumors the effectivity and the side effects of the two CSF were examined by questioning, clinical evaluation, and blood chemistry studies. G-CSF (480 μg subcutaneously (sc)) were used in 55 and GM-CSF (400 μg sc) in 28 chemotherapeutic cycles. The indications consisted in the treatment of leukocytopenia on the one hand and in the prophylaxis in subsequent cycles on the other hand. No difference between the two CSF could be found either with regard to postponement of the next cycle (G-CSF: 6.8 vs. GM-CSF: 7.3 days), or to the number of injections per cycle (G-CSF: 8 vs. GM-CSF: 12.5), or to the leukocyte (G-CSF: 2.1 vs. GM-CSF: 1.6 × 10³/μl) or platelet nadir (G-CSF: 0.5 vs. GM-CSF: 0.5 × 10⁵/μl; mean values of all cycles, respectively). Both CSF did not seem to influence the production of platelets. However, a difference between the two CSF was demonstrated with respect to the toxicity. Frequency (G-CSF: 38.5 % vs. GM-CSF: 69.3 %) as well as intensity of side effects causing a change of the drug (G-CSF: n = 1 vs. GM-CSF: n = 7) were lower in the case of G-CSF. In conclusion, these data demonstrate no difference was seen between G-CSF and GM-CSF with respect to the efficacy in patients with testicular cancer treated by standard chemotherapy. However, the use of G-CSF seems to be associated with lower toxicity.