Federated machine learning for a facilitated implementation of Artificial Intelligence in healthcare - a proof of concept study for the prediction of coronary artery calcification scores.

The implementation of Artificial Intelligence (AI) still faces significant hurdles and one key factor is the access to data. One approach that could support that is federated machine learning (FL) since it allows for privacy preserving data access. For this proof of concept, a prediction model for coronary artery calcification scores (CACS) has been applied. The FL was trained based on the data in the different institutions, while the centralized machine learning model was trained on one allocation of data. Both algorithms predict patients with risk scores ≥5 based on age, biological sex, waist circumference, dyslipidemia and HbA1c. The centralized model yields a sensitivity of c. 66% and a specificity of c. 70%. The FL slightly outperforms that with a sensitivity of 67% while slightly underperforming it with a specificity of 69%. It could be demonstrated that CACS prediction is feasible via both, a centralized and an FL approach, and that both show very comparable accuracy. In order to increase accuracy, additional and a higher volume of patient data is required and for that FL is utterly necessary. The developed "CACulator" serves as proof of concept, is available as research tool and shall support future research to facilitate AI implementation.

Five-year results of the Multicenter Randomized Controlled Open-Label Study of the CYPHER Sirolimus-Eluting Stent in the Treatment of Diabetic Patients with De Novo Native Coronary Artery Lesions (SCORPIUS) study: a German multicenter investigation on the effectiveness of sirolimus-eluting stents in diabetic patients.

BACKGROUND: Because a delayed arterial healing response after drug-eluting stent implantation has raised concerns about safety in diabetic patients, long-term effects of treatment with sirolimus-eluting stent (SES), as compared with bare-metal stent (BMS), have to be established. The aim of the 5-year follow-up of the randomized, controlled, open-label multicenter SCORPIUS study was to assess long-term safety and efficacy of the CYPHER (Cordis, Johnson & Johnson, Bridgewater, NJ) SES in percutaneous coronary intervention of diabetic patients. METHODS: A total of 190 patients with type 2 diabetes mellitus were randomized to receive either a SES (n = 95) or a BMS (n = 95). Dual-antiplatelet therapy (aspirin plus clopidogrel) was prescribed for at least 6 months. Clinical follow-up data were scheduled at 1, 8, and 12 months and 5 years. RESULTS: Treatment with SES resulted in a 16% decrease in the rate of major adverse cardiac events (36% vs 52%; hazard ratio 0.6, 95% CI 0.4-0.9; P = .02). This reduction in major adverse cardiac events with SES at 5 years was mostly attributable to a lower number of repeat target lesion revascularization (13% vs 29%; hazard ratio 0.4, 95% CI 0.2-0.7; P = .003). No differences between groups were observed for safety end points (all-cause mortality 21% vs 21%, cardiac death 15% vs 13%, repeat myocardial infarction 8% vs 9%, and stent thrombosis 5% vs 6%) at 5 years. CONCLUSIONS: The 5-year follow-up of the SCORPIUS trial demonstrates the long-term antirestenotic efficacy of SES in diabetic patients with significantly reduced target lesion revascularization and comparable rates of mortality, myocardial infarction, and stent thrombosis compared with BMS.

Long-term outcome after sirolimus-eluting stents versus bare metal stents in patients with diabetes mellitus: a patient-level meta-analysis of randomized trials.

BACKGROUND: Although it is widely believed that patients with diabetes mellitus obtain the greatest benefit from drug-eluting stents, convincing evidence on long-term efficacy and safety of these stents is lacking. METHODS: We performed a meta-analysis of individual patient data from four randomized trials including 583 patients comparing sirolimus eluting with bare metal stents (median follow-up of 4.2 years). These were the only specific trials reporting on drug-eluting stents in diabetic patients. The primary endpoint was the incidence of major cardiac events. The secondary endpoints were all-cause mortality and myocardial infarction as a safety endpoint and target lesion re-intervention as an efficacy endpoint. Stent thrombosis was also evaluated. RESULTS: There was a significant reduction in the overall hazard of major cardiac events (hazard ratio [HR] 0.48, 95% confidence interval [CI] 0.36-0.63, P < 0.001) with sirolimus-eluting stents. This was mostly due to a significant reduction in the overall hazard of repeat revascularization (HR 0.27, 95% CI 0.18-0.41, P < 0.001) in favor of sirolimus-eluting stents. However, the overall hazard of death (HR 0.91, 95% CI 0.59-1.41, P = 0.68) as well as death or myocardial infarction (HR 0.77, 95% CI 0.54-1.09, P = 0.14) were not significantly different between the groups. No significant differences were observed regarding stent thrombosis (HR 0.50, 95% CI 0.15-1.69, P = 0.26). CONCLUSIONS: Sirolimus-eluting stents are highly effective in reducing the risk for major cardiac events and safe in diabetic patients with coronary artery disease.

One-year results of the SCORPIUS study: a German multicenter investigation on the effectiveness of sirolimus-eluting stents in diabetic patients.

OBJECTIVES: This study sought to analyze the effectiveness of drug-eluting stents in a high-risk group of diabetic patients. Previously, this had been analyzed only in substudies of larger trials or in clinical investigations enrolling a small number of patients. BACKGROUND: Drug-eluting stents are highly effective in reducing the rate of in-stent restenosis. METHODS: Two hundred patients with diabetes and de novo coronary artery lesions were enrolled in 16 centers: 98 were randomly assigned to sirolimus-eluting stents (SES) and 102 received bare-metal stents (BMS). The primary end point was in-segment late luminal loss. Major adverse cardiac events (MACE) rate was analyzed at 30 days and 8 and 12 months. RESULTS: The extent of in-segment late luminal loss in the SES group was 0.18 mm compared with 0.74 mm in the BMS group. In-segment restenosis was identified on follow-up angiography in 8.8% of the patients in SES and in 42.1% in BMS (p < 0.0001). Target lesion revascularization was performed in 5.3% of the patients in SES and in 21.1% of the patients in BMS (p = 0.002). The SES was effective in the treatment group with oral diabetic medication as well as in the insulin-dependent treatment group (3.6% SES vs. 38.8% BMS). There was no subacute stent thrombosis in the SES group up to 1 year. The MACE rate was not significantly different at 30 days. At 12 months, MACE rate was 14.7% in SES versus 35.8% in BMS. CONCLUSIONS: The SES is safe and highly effective in patients with diabetes mellitus and coronary artery disease and associated with a significant decrease in the extent of late luminal loss.

[Preventive whole-body screening encompassing modern imaging using magnetic resonance tomography]. / Präventives Ganzkörperscreening unter Einbeziehung moderner Bildgebung mit Hilfe der Magnetresonanztomographie.

BACKGROUND: With respect to the prognosis of the population and costs, the focus of the health-care system should lie more on preventive medicine in the future. The value of screening examinations as secondary prevention is, however, controversial, as only few investigations exist. PATIENTS AND METHODS: The authors report on 1,007 consecutive patients who underwent a screening examination based on clinical examinations and whole-body magnetic resonance imaging (MRI) of the brain, arterial system, heart and abdomen in a private outpatient center. Clinical examinations consisted of physical examination, ECG, stress ECG, lung function test, ultrasound of carotid vessels and thyroid, blood and urinary tests. Besides clinical tests, all patients were studied by routine MRI of the brain, the heart (exclusive of the coronary system) and whole-body MR angiography. In the same setting, 855 of the patients (855/1,007) underwent an MR colonoscopy in dark-lumen technique, and the remaining 152 of the patients (152/1,007) an abdominal MR overview (T(1) Vibe). Patients with MR colonography obtained triple-dose gadolinium-BOPTA. RESULTS: Screening was performed in 1,007 patients, 71% were men and 29% women. Altogether, 895 relevant findings were reported in 1,007 patients. 24% of the findings were detected exclusively by MRI. Most of the MR-based diagnoses were cardiovascular in nature, including 29 silent myocardial infarctions (3.2%), 27 aortic aneurysms (3%), two of them being > 5 cm in diameter, eleven intracranial extraaxial tumors (1.2%), 75 colonic polyps (8.4%), four neoplastic tumors (0.44%; three renal cell carcinomas, one bronchial carcinoma), and two cerebral aneurysms (0.22%). The MRI results of two colonic polyps were false-positive. CONCLUSION: Whole-body screening reveals a number of therapeutically relevant diagnoses, primarily of cardiovascular origin. MRI yields valuable additional diagnoses that have a significant impact on the further medical strategy. The value of the screening examination lies mainly in the experienced interpretation of both radiologic and clinical tests and the integration into an overall medical concept and clinical management.

Analysis of 14 trials comparing sirolimus-eluting stents with bare-metal stents.

BACKGROUND: The long-term effects of treatment with sirolimus-eluting stents, as compared with bare-metal stents, have not been established. METHODS: We performed an analysis of individual data on 4958 patients enrolled in 14 randomized trials comparing sirolimus-eluting stents with bare-metal stents (mean follow-up interval, 12.1 to 58.9 months). The primary end point was death from any cause. Other outcomes were stent thrombosis, the composite end point of death or myocardial infarction, and the composite of death, myocardial infarction, or reintervention. RESULTS: The overall risk of death (hazard ratio, 1.03; 95% confidence interval [CI], 0.80 to 1.30) and the combined risk of death or myocardial infarction (hazard ratio, 0.97; 95% CI, 0.81 to 1.16) were not significantly different for patients receiving sirolimus-eluting stents versus bare-metal stents. There was a significant reduction in the combined risk of death, myocardial infarction, or reintervention (hazard ratio, 0.43; 95% CI, 0.34 to 0.54) associated with the use of sirolimus-eluting stents. There was no significant difference in the overall risk of stent thrombosis with sirolimus-eluting stents versus bare-metal stents (hazard ratio, 1.09; 95% CI, 0.64 to 1.86). However, there was evidence of a slight increase in the risk of stent thrombosis associated with sirolimus-eluting stents after the first year. CONCLUSIONS: The use of sirolimus-eluting stents does not have a significant effect on overall long-term survival and survival free of myocardial infarction, as compared with bare-metal stents. There is a sustained reduction in the need for reintervention after the use of sirolimus-eluting stents. The risk of stent thrombosis is at least as great as that seen with bare-metal stents.

Frequency and outcomes of acute renal failure following thoracic aortic stent-graft placement.

We assessed the incidence, correlates, and outcomes of acute renal failure (ARF) after thoracic aortic stent-graft placement. Postprocedural ARF is an inherent complication of catheter-based interventional procedures that use intra-arterial contrast agents and has adverse effects on short- and long-term outcomes. However, few data exist on the incidence, predictors, and outcomes of ARF after thoracic aortic stent-graft placement. We analyzed data of 97 patients (64.4 +/- 11.6 years of age; 73% men) who underwent thoracic aortic stent-graft placement from July 1999 to October 2005. Postprocedural ARF was defined as an increase > or = 25% and/or > or = 0.5 mg/dl in preprocedural serum creatinine at 48 hours after the procedure. Baseline estimated glomerular filtration rate was 65 +/- 24 ml/min/1.73 m2. Chronic kidney disease (glomerular filtration rate < or = 60 ml/min/1.73 m2) at baseline was present in 45% of patients. During the stent-graft procedure, patients received 307 +/- 188 ml of nonionic contrast medium. Postprocedural ARF occurred in 33 patients (34%), and 3 required dialysis. Multivariable analysis identified American Society of Anesthesiologists class > 3 (odds ratio 5.53, 95% confidence interval 1.71 to 17.85, p = 0.004) and duration of the stent-graft procedure (odds ratio 1.01, 95% confidence interval 1.001 to 1.014, p = 0.022) as independent predictors of postprocedural ARF. Compared with patients without ARF, those with ARF had markedly higher 30-day (18.2 +/- 6.7% vs 1.6 +/- 1.6%, p = 0.0022) and 1-year (35.2 +/- 8.6% vs 10.1 +/- 3.9%, p = 0.001) mortality. In conclusion, postprocedural ARF is a frequent complication of thoracic aortic stent-graft placement and has a significant adverse effect on 30-day and 1-year survival. Baseline factors identified in our study as associated with increased risk of ARF may facilitate a comprehensive informed consent process by way of patient education. In addition, identification of an at-risk subset may allow modification of reversible periprocedural factors that may help decrease postprocedural ARF.

Underlying aortic pathology and clinical health status determine success of endovascular stent-grafting for descending thoracic aortic disease.

Despite advances in medical and surgical treatment, acute as well as chronic diseases of the thoracic aorta are still associated with a high mortality. For the descending thoracic aorta, endovascular stent-graft placement competes with surgical therapy for clinical outcome. From July 1999 till December 2004, a total of 84 patients (64 +/- 14 years) with aortic disease of the descending thoracic aorta were treated. Nine patients had acute (AAD) and 35 chronic aortic dissection (AD), 16 had thoracic aortic aneurysms (TAA), 21 had penetrating aortic ulcer (PAU), and 3 patients had traumatic dissection (trans). Initial clinical status was assessed using the American Society of Anesthesiologists (ASA) classification. Fifty-three patients were in class 2, 16 in class 3, 8 in class 4, and 7 in class 5. Stent-graft placement was performed in the cardiac catheterization laboratory with the patient under general anesthesia. Technical success was obtained in 81/84 patients (96%). Within 30 days, seven patients (8%) died, four of them due to aortic rupture. In 14 patients, additional stent-grafts had to be implanted due to type I endovascular leakage (n = 5) or additional entry site adding up to a total of 107 implanted stent-grafts. During a follow-up period of 21 +/- 18 months, 17 additional patients died (22%). In 10 patients, death was disease- or procedure-related (13%). This long-term mortality depended on the underlying disease and was highest in the group with TAA (45%) followed by AAD (38%) and AD (18%). Patients in ASA class 4 and 5 had a significantly worse outcome. No aortic-related death occurred among patients with PAU or traumatic transsections. Overall, there was only one transient neurological deficit. Endovascular stent-graft placement has acceptable results in the treatment of patients with disease of the descending thoracic aorta. The outcome strongly depends on the underlying aortic pathology and the clinical health status of the patients. Randomized trials are necessary in order to establish the exact value of this new therapeutic option.

Endovascular stent-graft treatment of penetrating aortic ulcer: results over a median follow-up of 27 months.

BACKGROUND: Penetrating aortic ulcer (PAU) is increasingly acknowledged as a pathological variant of classic false-lumen aortic dissection with a high incidence of bleeding complications and rupture in up to 40% of patients. The objective of this study was to investigate the results of endovascular stent-graft placement for the treatment of patients with PAUs. METHODS: Between July 1999 and December 2004, endovascular stent-graft repair of PAU was performed in 22 patients (69.1 +/- 7.8 years, 16 men), 3 (14%) of whom had contained aortic rupture. Stent-graft placement was performed in the cardiac catheterization laboratory with the patient under general anesthesia, using a surgical access. RESULTS: Procedural success was achieved in all but 1 patient (technical success rate 96%). Postoperatively, 1 (5%) patient had minor stroke with transient amentia. There were no other inhospital complications or deaths. During a median follow-up of 27 (range 1-62) months, 1 patient underwent adjunctive stent-graft placement for type I endoleak. Three patients died unrelated to the aortic disease late during follow-up. Overall survival rates were 100% at 30 days, 100% at 1 year, 82.5% +/- 11.3% at 2 years, and 61.9% +/- 20.0% at 5 years. CONCLUSIONS: Endovascular stent-graft treatment is an effective treatment for patients with PAU and is associated with low procedural morbidity. Both acute and midterm mortality of this novel treatment concept appear to be favorable compared with the natural course of the disease.

Endovascular stent-graft placement in aortic dissection: a meta-analysis.

AIMS: This article summarizes all available published data with respect to clinical success, complications, and outcomes of endovascular stent-graft placement among patients with descending aortic dissection (AD). METHODS AND RESULTS: We performed a meta-analysis of all published series on retrograde endovascular stent-graft placement encompassing >or=3 patients with AD. Thirty-nine studies, involving a total of 609 patients, were included. Procedural success was reported in 98.2+/-0.5% of patients. Major complications were reported in 11.1+/-1.4%, with the most dreaded neurologic complications in 2.9+/-0.7% patients. Periprocedural stroke was encountered more frequently than paraplegia (1.9+/-0.6% vs. 0.8+/-0.4%). Overall complications were significantly higher in patients undergoing stent-graft placement for acute AD than in patients with chronic AD (21.7+/-2.8% vs. 9.1+/-2.3%, P=0.005). The overall 30-day mortality was 5.3+/-0.9%, and was three-fold higher in patients with acute AD when compared with chronic AD (9.8+/-2.2% vs. 3.2+/-1.4%, P=0.015). In addition, 2.8+/-0.7% of patients died over a mean follow-up period of 19.5+/-7.1 months. Kaplan-Meier analysis yielded overall survival rates of 90.6+/-1.6% at 6 months, 89.9+/-1.7% at 1 year, and 88.8+/-1.9% at 2 years, respectively. CONCLUSION: Endovascular stent-graft placement in type B-AD is technically feasible with success rates of >95% in selected cohort. Although minimally invasive, major complications occurred in 14-18% of patients depending upon the acuity of presentation, with very low incidence of paraplegia. Both, acute and mid-term mortality of this novel treatment strategy appear to favourably compare with surgical treatment but further studies are necessary to compare stent-graft placement with medical treatment in uncomplicated AD.

Endovascular stent-graft placement for acute and contained rupture of the descending thoracic aorta.

OBJECTIVES: To identify determinants of postinterventional death after endovascular stent-graft placement for acute rupture of the descending thoracic aorta, an emerging therapeutic modality for this highly life-threatening condition. METHODS: Between July 1999 and November 2004, 17 patients (14 males; mean age, 65+/-16 (25-83) years) underwent stent-graft repair of the descending thoracic aorta for acute rupture from a thoracic aneurysm (TAA, n=6), acute aortic dissection (AAD, n=6), penetrating aortic ulcer (PAU, n=3), or blunt chest trauma (n=2). Immediate, 30-day, 1-year, and 3-year mortality was assessed. Twenty-one clinical and procedural variables were evaluated in a post-hoc analysis regarding their influence on mortality. Of these, four preprocedural factors with the greatest impact were used to construct a rupture score with a scale from 0 (no adverse prognostic factors present) to 4 (all four adverse factors present). RESULTS: Stent-graft placement was technically feasible in all patients. Complete exclusion of the ruptured aortic pathology could be achieved in only 11 (65%) patients, despite implantation of 1.6+/-0.9 stent-grafts per patient, with a median length of 130 mm. There was one procedure-related early complication (bleeding at the access site). One patient died immediately following the procedure because of progressive mediastinal hematoma, although the rupture site was effectively sealed. Overall survival rates were (76.5+/-10.3)% at 30 days and (52.9+/-12.1)% at 1 year and remained at (52.9+/-12.1)% at 3 years. The four most important preprocedural denominators of death were (1) TAA or AAD as the underlying etiology of aortic rupture (P=0.024), (2) maximum aortic diameter>5 cm (P=0.024), (3) presence of mediastinal hematoma (P=0.056), and (4) an estimated lesion length requiring >1 stent-graft to be covered (P=0.009). Furthermore, residual leakage at the conclusion of the procedure (P=0.009), postprocedural need for dialysis (P=0.004), and prolonged ventilation (P=0.043) were significantly associated with postprocedural death. Using a threshold of >or=3, the rupture score constructed on the basis of the four preprocedural denominators of death was found to be well suited to discriminate postprocedural death (1-year survival: (20.0+/-12.7)% in patients with a rupture score>or=3 vs. 100% in patients with a rupture score<3, P=0.001). CONCLUSION: Endovascular stent-graft placement in patients with acute aortic rupture was technically feasible, albeit still associated with high mortality. A simple risk score constructed in retrospect, on the basis of preprocedural prognostic factors, appeared to provide a useful separation of candidates who are likely to benefit from a straightforward endovascular procedure and should be tested prospectively in future studies.

Endovascular stent-graft treatment of aortic dissection: determinants of post-interventional outcome.

AIMS: To investigate the results of endovascular stent-graft placement for the treatment of patients with type B aortic dissection (B-AD). METHODS AND RESULTS: A total of 38 patients (62+/-10 years, 32 male) with acute (n=10) and chronic (n=28) type B-AD were treated with endovascular stent-grafts. The implantation procedure was successful in all patients. Peri-procedural non-fatal complications occurred in four (11%) patients. Overall, 4/38 (11%) patients died during the in-hospital period. Patients undergoing stent-graft placement for acute AD had a significantly higher in-hospital mortality than patients with chronic AD (40 vs. 0%, P=0.001). During a median follow-up of 18 (1-57) months, there were six additional deaths. Overall survival rates were 97.4+/-2.6% at 30 days, 80.4+/-6.7% at 1 year, 73.2+/-7.8% at 2 years, and 54.9+/-16.9% at 4 years. Patients with a poor clinical health status (ASA class > 3) had a significantly reduced life expectancy compared with patients with only moderate co-morbidities (ASA class 3) pre-operatively (HR=29.5, 95% CI 1.5-581.9, P=0.026) and increased age (HR=1.1, 95% CI 0.9-1.2, P=0.084) were independent determinants of post-interventional mortality. CONCLUSION: Endovascular stent-graft treatment is a safe alternative for patients with AD. The pre-operative clinical health status of the patient is the most important determinant of post-interventional outcome. Careful patient selection is thus of particular importance.

The EchoMap System: online integration of intracoronary ultrasound and Doppler images into angiographic images during cardiac catheterization. Influence on radiation exposure and procedure parameters.

The EchoMap system allows online integration of intravascular ultrasound (IVUS) and intracoronary Doppler (ICD) images into angiographic images during catheterization, providing exact localization of the IVUS transducer and the ICD wire tip position. Although this is a major advance, the use of the system could lead to more angiographic documentation sequences and enhanced radiation exposure. We investigated the influence of system use on radiation and procedure parameters. During a 22-month period, 794 patients underwent coronary angiography with simultaneous performance of IVUS and/or ICD. The EchoMap system was applied in 392 patients ("EchoMap group"), the remaining 402 patients formed the "No-EchoMap group." Multivariate regression analysis showed no independent association between the use of EchoMap and fluoroscopy time (14.7 +/- 8.5 minutes in the EchoMap group vs 14.5 +/- 10 minutes in the No-EchoMap group, P = NS) or dose area product (7589 +/- 4916 in the EchoMap group vs 7031 +/- 5434 cGy x cm(2), P = NS). EchoMap use was significantly associated with a moderate increase in contrast media amount (392 +/- 162 in the EchoMap vs 356 +/- 155 mL in the No-EchoMap group, P = 0.001). In conclusion, the use of the EchoMap system had no significant influence on radiation exposure during cardiac catheterization, whereas it was associated with a moderate increase in contrast media amount.

Impact of gender on femoral access complications secondary to application of a collagen-based vascular closure device.

BACKGROUND: Vascular complications at the femoral access site continue to be a significant problem after cardiac catheterization procedures. It was the aim of the present study to assess the impact of gender on the incidence of severe femoral access complications following the application of a collagen-based vascular closure device after transfemoral catheterization procedures. METHODS: A total of 1,294 consecutive patients (977 male, 317 female) underwent closure of femoral access sites with 8F collagen-based vascular closure devices (Angioseal) immediately after diagnostic or interventional coronary catheterization procedures, independently of the coagulation status. All patients were closely monitored for the occurrence of complications during the following 24 hours. RESULTS: Between male and female patients, there was no difference in the technical performance of the device with successful deployment being achieved in 96.7% and 95.9%, respectively (p=0.60). Severe access complications were found to be significantly higher in female versus male patients (1.6% vs. 0.2%; Odds ratio 7.7, 95% confidence interval 1.5-40.1; p=0.015), although similar accomplishment of an immediate hemostasis was seen in 92.8% and 92.4% of male and female patients (p=0.98). CONCLUSION: Women show a significantly increased risk of developing severe femoral access complications secondary to the application of a collagen-based vascular closure device, although the overall incidence of these complications is relatively low. We speculate that the increased risk in women may be related to smaller arterial dimensions, which could be evaluated by femoral angiography prior to deployment of a closure device.

Identification of syndrome X using intravascular ultrasound imaging and Doppler flow mapping.

BACKGROUND: The purpose of this study was to assess the morphological changes and physiological function of coronary arteries in patients presenting with chest pain but having normal coronary angiograms, using intravascular ultrasound imaging (IVUS) and intracoronary Doppler (ICD) flow measurements, in order to elucidate the mechanism of syndrome X. METHODS: A total of 126 patients [67 males, 59 females, mean age (53.1 +/- 13.0) years] who experienced chest pain but had normal coronary angiograms were included in this study. ICD flow measurements of the left anterior descending coronary artery (LAD) were performed using a Cardiometrics FloMap II system. Coronary flow velocity reserve (CFVR) was defined as the ratio of the average peak velocity during hyperemia to that at baseline, induced by an intracoronary bolus injection of 18 microg adenosine. A 3.2F or 2.9 F 30 MHz mechanical rotating ultrasound catheter (CVIS, Boston Scientific) or a 3.0 F 20 MHz electronic ultrasound catheter (Endosonics) was used for IVUS. RESULTS: The mean CFVR value of the LAD was 2.71 +/- 0.74. Reduction of CFVR (< 3.0) was found in 82 of 126 (65.1%) patients. IVUS images of the LAD were available for 109 patients. Plaque formation was detected in 76/109 (69.7%) patients. Based on the presence or absence of plaque formation as well as the reduction or non-reduction of CFVR, patients were divided into four groups: Group I (n = 10), normal IVUS findings and normal CFVR; Group II (n = 23), normal IVUS findings with reduction in CFVR; Group III (n = 29), IVUS evidence of plaque formation but normal CFVR; and Group IV (n = 47), IVUS evidence of plaque formation with reduction in CFVR. CONCLUSION: This study shows the important clinical value of a combination of IVUS and ICD in diagnosing patients with angiographically normal coronary arteries. Only 10% of patients studied (Group I) were found to be truly free of coronary disease, while 20% of patients (Group II) would be diagnosed as suffering from syndrome X.

Spectrum of remodeling behavior observed with serial long-term (>/=12 months) follow-up intravascular ultrasound studies in left main coronary arteries.

Most intravascular ultrasound (IVUS) studies of arterial remodeling in native coronary arteries reported a remodeling index obtained at a single time point. We analyzed serial IVUS examinations, including the vessel cross-sectional area changes (remodeling behavior), of 60 hemodynamically nonstenotic left main lesions (baseline vs 18.4 +/- 9.4 months follow-up). Lumen reduction resulted from vessel reduction (sometimes despite plaque + media decrease), plaque + media increase (with or without vessel increase), or both. The percent annual changes in lumen area correlated strongly with changes in vessel (r = 0.84), but not with changes in plaque + media area. Plaques were classified as group A lesions, reflecting positive remodeling behavior (vessel changes >0), or group B lesions, reflecting negative (or intermediate) remodeling behavior (vessel changes <==0). Both groups did not differ significantly in demographics, laboratory data, and medications. Group A lesions (n = 40) more often showed plaque + media increase than group B lesions (32 of 40 [80%] vs 9 of 20 [45%]; p = 0.02). Group A lesions had, on average, mild annual lumen increase despite mild plaque + media increase, i.e, overcompensation of remodeling for plaque + media increase (vessel increase greater than plaque + media area increase, 19 of 40 [47%]). Conversely, group B lesions (n = 20) showed a significant lumen area reduction (-2.8 +/- 2.6 mm(2)/year) as a result of a decrease in vessel area only. Thus, serial long-term reduction of lumen size may result from vessel shrinkage (sometimes despite plaque decrease), plaque increase (with or without vessel increase), or both; overall, only the remodeling behavior has a significant relation to lumen changes. More than 30% of lesions show a negative remodeling behavior, which shows no relation to patient characteristics or initial plaque burden.

Aortoesophageal fistula secondary to stent-graft repair of the thoracic aorta.

PURPOSE: To report the incidence and management of aortoesophageal fistula (AEF) secondary to endovascular stent-graft repair of the descending thoracic aorta. METHODS: A retrospective review was conducted of patients treated at our facility between July 1999 and June 2003. During this interval, 60 patients (46 men; average age 66+/-10 years) underwent thoracic aortic stent-graft placement for a variety of pathologies. RESULTS: AEF occurred in 3 (5%) patients. One 62-year-old man presented with recurrent back pain and fever and died suddenly due to fatal exsanguination; the AEF was revealed at necropsy. The other 2 patients (both women) presented with hematemesis after endovascular repair of thoracic aortic aneurysms. AEF was detected by esophagogastroduodenoscopy. Both patients were treated conservatively, as open surgical repair was refused because of their general condition. Both patients developed severe mediastinitis and died after 5 weeks and 10 months, respectively. CONCLUSIONS: Aortoesophageal fistula is, in our experience, a catastrophic complication of endovascular stent-graft placement. Treatment options are very limited, as these patients are usually not candidates for open surgery. Outcome under conservative management is, however, almost invariably fatal.

Intracoronary brachytherapy, a promising treatment option for diabetic patients: Results from a European multicenter registry (RENO).

Despite advances in the interventional treatment of coronary disease, diabetics still have double the case fatality rate as nondiabetics. The purpose of this analysis from the Radiation in Europe With Novoste (RENO) registry was to assess the clinical and angiographic 6-month outcome of diabetic patients in comparison to nondiabetic patients after localized beta-radiation. A total of 1,098 patients (83.8% with in-stent restenosis) treated with the Novoste Beta-Cath system in Europe were enrolled in the RENO registry. Diabetes was, irrespective of the type of lesion treated, no significant risk factor for major adverse cardiac events or target vessel revascularization. Individuals with diabetes (n = 256) and without diabetes (n = 833) displayed no significant differences concerning clinical or angiographic endpoints. Vascular brachytherapy appears to be the first technique to even out the increased risk of diabetic patients undergoing percutaneous coronary interventions in the routine clinical setting. Thus, intracoronary brachytherapy represents a promising treatment option for diabetic patients.

Successful reduction of in-stent restenosis in long lesions using beta-radiation--subanalysis from the RENO registry.

PURPOSE: Long lesions remain a challenging task in interventional cardiology, with a high propensity of restenosis, especially within the stented segment. Although intracoronary gamma-radiation has been proved to reduce diffuse in-stent restenosis in long lesions, such an effect remains to be determined using beta-radiation. METHODS AND MATERIALS: Of 1098 consecutive patients at 46 European centers treated with localized beta-radiation ((90)Sr, Novoste Beta-Cath System), 139 patients (mean age 61.5 +/- 10.7 years, 84% male, 22% with diabetes mellitus) with lesions treated using a >40-mm source length underwent radiation using a single 60-mm source train (34%) or a stepping/pullback procedure with a 30-mm (12%) or 40-mm (87%) source length after conventional interventional procedures. The mean lesion length was 35.3 +/- 17.9 mm. RESULTS: Technical success was achieved in 96% of cases. Geographic miss was noted in 9 patients (6.5%). The reference (placebo) group was obtained from the Washington Hospital Center for In-Stent Restenosis Trial (WRIST) and the WRIST Trial for long lesions (LONG WRIST) studies by selecting the cases (94 patients) that required a dummy source length >/=13 seeds (or >51 mm in length). Statistically significant improvement was noted in late angiographic restenosis (34.7% vs. 76.5%, p <0.0001), target vessel revascularization (14.9% vs. 60.6), and major adverse cardiac events (i.e., death, myocardial infarction, or total vessel revascularization) (17.9% vs. 64.9%, p <0.0001) at 6 months in reference to the nonradiation group. CONCLUSION: This subanalysis from the Radiation in Europe with Novoste study confirms the safety and efficacy of beta-radiation combined with conventional interventional procedures in patients with diffuse, long, in-stent restenosis