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Biomedical subjects

Guy Friedrich

Publications and source records attributed to Guy Friedrich.

14 recordsLinked to original sources
PubMed2006

Risk factors of postoperative nephropathy in patients undergoing innovative CABG and intraoperative graft angiography.

INTRODUCTION: Intraoperative graft angiography is considered gold standard in quality control of innovative CABG techniques. Iodixanol, an iso-osmolar, non-ionic contrast agent has been safely applied in patients with impaired renal function. We aimed to quantify postoperative nephropathy in CABG patients undergoing intraoperative angiography and to define associated risk factors. METHODS: One hundred and thirty-five patients, aged 61 years (range: 43-83), underwent intraoperative angiography following CABG (36 robotically assisted CABG via sternotomy, 41 OPCAB and MIDCAB, 51 AHTECAB, 7 BHTECAB). In all patients iodixanol (Visipaque) was used, median amount: 150 ml (range: 20-500). Nephropathy was defined as an increase in serum creatinine concentration >or= 0.5 mg/dl compared with preoperative values. RESULTS: Nephropathy occured in 19/135 (14%) patients, and was correlated with the following variables: preoperative serum creatinine (p = 0.015, r = 0.208), age (p = 0.008, r = 0.229), postoperative peak troponin T levels (p < 0.001, r = 0.545), postoperative CK-MB peak levels (p = 0.028, r = 0.189), and presence of peripheral vascular disease (p = 0.011). No correlation was found for the contrast agent amount, diabetes mellitus, hypertension, preoperative urea level, cardiopulmonary bypass time, aortic cross clamp time, postoperative CK peak levels. Multivariate analysis showed that postoperative peak troponin T levels (p < 0.001), preoperative serum creatinine (p = 0.031), and patient age (p = 0.043) were independently associated with a postoperative increase of serum creatinine. In all 19 patients with postoperative nephropathy serum creatinine levels returned to preoperative levels. CONCLUSION: Patients with older age and elevated serum creatinine levels undergoing innovative CABG and intraoperative angiography were at increased risk of postoperative nephropathy. However, no correlation was found between the amount of contrast agent (iodixanol) applied and the nephropathy rate and none of the nephropathy cases persisted.

Adult↗
PubMed2006

Integrated coronary revascularization: percutaneous coronary intervention plus robotic totally endoscopic coronary artery bypass.

BACKGROUND: Robotic totally endoscopic coronary artery bypass (TECAB) of the left anterior descending artery (LAD) coupled with percutaneous coronary intervention (PCI) of a second coronary artery has been investigated in patients with multivessel disease to provide a minimally invasive therapeutic option. METHODS AND RESULTS: TECAB of the LAD was performed using the left internal mammary artery (LIMA). A second lesion was treated with PCI before surgery, simultaneously, or after surgery. Three-month angiographic follow-up was performed in all patients and was subject to independent review. A total of 27 patients requiring double vessel revascularization were treated at 7 centers. Eleven patients underwent PCI before surgery, 12 patients underwent PCI after surgery, and 4 patients underwent simultaneous surgical and percutaneous intervention. Ten patients (37%) were treated with bare metal stents, whereas 17 patients (63%) were treated with drug-eluting stents. Postoperative angiographic evaluation demonstrated an overall LIMA anastomotic patency of 96.3% and PCI vessel patency of 66.7%. There were no deaths or strokes. One patient experienced a perioperative myocardial infarction. Eight of 27 patients (29.6%) required reintervention, 1 LIMA anastomotic stenosis (3.7%), 3 after bare metal stent (30%), and 4 after drug-eluting stent placement (23.5%). CONCLUSIONS: Integrated revascularization treatment plans provide minimally invasive options for patients with multivessel coronary artery disease. This approach may be accomplished with no mortality, low perioperative morbidity, and excellent angiographic LIMA patency. The reintervention rate after PCI in this series was higher than that reported elsewhere and should be investigated further. The choice of suitable vessel, type of stent and timing of the treatment must be carefully considered before implementing this hybrid strategy.

Adult↗
PubMed2006

Effect of intensive versus standard lipid-lowering treatment with atorvastatin on the progression of calcified coronary atherosclerosis over 12 months: a multicenter, randomized, double-blind trial.

BACKGROUND: Recent clinical trials have suggested that intensive versus standard lipid-lowering therapy provides for additional benefit. Electron-beam computed tomography provides the opportunity to quantify the progression of coronary artery calcification (CAC) in serial measurements. METHODS AND RESULTS: In a multicenter, randomized, double-blind trial, 471 patients (age 61+/-8 years) who had no history of coronary artery disease and no evidence of high-grade coronary stenoses (>50% diameter reduction) were randomized if they had > or =2 cardiovascular risk factors and moderate calcified coronary atherosclerosis as evidenced by a CAC score > or =30. Patients were assigned to receive 80 mg or 10 mg of atorvastatin per day over 12 months. Progression of CAC volume scores could be analyzed in 366 patients. After pretreatment with 10 mg of atorvastatin for 4 weeks, 12 months of study medication reduced LDL cholesterol from 106+/-22 to 87+/-33 mg/dL in the group randomized to receive 80 mg of atorvastatin (P<0.001), whereas levels remained stable in the group randomized to receive 10 mg (108+/-23 at baseline, 109+/-28 mg/dL at the end of the study, P=NS). The mean progression of CAC volume scores, corrected for the baseline CAC volume score, was 27% (95% CI 20.8% to 33.1%) in the 80-mg atorvastatin group and 25% (95% CI 19.1% to 30.8%) in the 10-mg atorvastatin group (P=0.65). CAC progression showed no relationship with on-treatment LDL cholesterol levels. CONCLUSIONS: We did not observe a relationship between on-treatment LDL cholesterol levels and the progression of calcified coronary atherosclerosis. Over a period of 12 months, intensive atorvastatin therapy was unable to attenuate CAC progression compared with standard atorvastatin therapy. The possibility remains that the time window was too short to demonstrate an effect.

Adult↗
PubMed2005

Robotic totally endoscopic coronary artery bypass and catheter based coronary intervention in one operative session.

A 56-year-old male patient underwent robotically assisted totally endoscopic left internal mammary artery (LIMA) to left anterior descending artery (LAD) grafting. After protamine administration complete heart block developed in the patient. On intraoperative angiography the LIMA to LAD graft was perfectly patent but an acute occlusion of the right coronary artery (RCA) was noted. We performed an immediate on table percutaneous coronary angioplasty and stent placement to the RCA. The heart regained sinus rhythm and the wall motion abnormalities on the back wall of the heart resolved. No clinical symptoms indicating ongoing myocardial ischemia were noted postoperatively. This case demonstrates that a hybrid procedure of robotic totally endoscopic coronary artery bypass grafting and catheter based coronary intervention is feasible in one simultaneous session.

Angioplasty↗
PubMed2005

Cardiac transplantation complicated by acute thrombotic occlusion of the right coronary artery.

We report the case of a 63-year-old male patient undergoing cardiac transplantation due to fourth time aortic valve endocarditis. The postoperative course was complicated by thrombotic occlusion of the right coronary artery (RCA) causing acute right ventricular myocardial infarction, which required extracorporeal membrane oxygenation. The RCA could be reopened by catheter-based intervention and the patient stabilized. In order to avoid further immobilization, a right ventricular assist device was implanted and an aortocoronary bypass to the RCA was performed. After that, the patient stabilized progressively, could be weaned from the assist device, and was discharged home 6 weeks after transplantation. On coronary angiography, which is routinely performed 4 to 6 weeks after transplantation, a fistula from the RCA to the right ventricle was detected which was treated conservatively. Five months after transplantation, the patient is in good clinical condition without signs of recurrent endocarditis. This case shows that intense interdisciplinary cooperation of cardiac specialists allows the successful management of very complex patients in serious clinical conditions.

Aortic Valve↗
PubMed2005

Does preoperative multislice computed tomography predict operative times in total endoscopic coronary artery bypass grafting?

OBJECTIVE: Multislice computed tomography (MSCT) is currently discussed as a potential tool for procedure planning in endoscopic heart surgery. We aimed to assess the influence of various thoracic measurements on operative times in arrested heart totally endoscopic coronary artery bypass grafting (AHTECAB). METHODS: 34 patients (aged 59 years, 71% male) scheduled for AHTECAB were examined prospectively with ECG-gated 16-channel MSCT angiography of coronary arteries and internal mammary arteries. All AHTECABs were single LIMA to LAD bypass operations using the Da Vinci telemanipulator and the ESTECH remote access perfusion system. RESULTS: The LIMA-LAD distances were: I (at origin of the first diagonal branch) 4.3 cm (2.5-6.0), II (aortic valve level) 3.7 cm (1.1-6.4), III (mitral valve level) 2.9 cm (0.7-5.0), and IV (basis cordis) 2.3 cm (0.6-4.3). The anterioposterior thoracic diameter was 12.4 cm (8.9-15.6), and the transverse diameter was 24.9 cm (21.1-26.8). LIMA-LAD distances I (P = .025, r = .396) and III (P = .042, r = .356) significantly correlated with the anastomotic time. Increased rotation of the heart to the left was associated with a decreased cardiopulmonary bypass time (p = .016, r = -.451). CONCLUSION: These data suggest that MSCT has the potential to predict operative times in robotic AHTECAB.

Coronary Angiography↗
PubMed2005

Assessment of health-related quality of life after coronary revascularization.

The use of patient-oriented outcomes, in particular health-related quality if life (HRQOL), to evaluate coronary revascularization is continuously increasing. Current data underline that patients undergoing conventional CABG show a tremendous improvement of HRQOL status as early as 3 months postoperatively. There seems to be no clear benefit concerning HRQOL for off-pump coronary surgery versus conventional CABG. The benefits of minimal invasive CABG via mini-thoracotomy are compromised by increased incidence of pain during the immediate postoperative period. Totally endoscopic approaches seem to be more effective with regard to pain reduction and resume of every day activities. Compared to catheter-based interventions there is evidence that conventional CABG offers significant advantages over PCI. The influence of drug-eluting stents and newer surgical techniques on HRQOL remains to be determined. Inclusion of HRQOL data in CABG and PCI databases can play a central role in order to identify patient groups who benefit the most from each revascularization strategy.

Angioplasty, Balloon, Coronary↗
PubMed2004

Sternal osteomyelitis complicating percutaneous coronary artery stenting.

Hematogenous sternal osteomyelitis is a rare infection that has been associated with i.v drug abuse and blunt thoracic trauma, but iatrogenic infections have also been described following resuscitation and in conjunction with hemodialysis catheters. Staphylococcus aureus is the most common causative organism. Stenting is the preferred treatment for isolated stenosis of the coronary artery and is associated with a low complication rate and high patency rate. Such intravascular procedures are rarely complicated by infections. A 72-year-old man developed hematogenous sternal osteomyelitis following coronary artery stenting. Radiological diagnosis was made using CT scan and MRI, and blood cultures and aspiration fluid from the infected soft tissue were positive for S. aureus. Initial therapy consisted of i.v. second-generation cephalosporin followed by oral cephalexin and later linezolid. Prolonged antibiotic therapy without surgical intervention was successful in controlling this rare complication. The patient was well at the one-year follow up, with patent stent and no signs for recurrent osteomyelitis. Although transcutaneous stenting is a widely accepted strategy for treating stenosed arteries, this case highlights the possibility of hazardous infectious complications associated with such procedures.

Aged↗
PubMed2004

C-reactive protein plasma levels but not factor VII activity predict clinical outcome in patients undergoing elective coronary intervention.

BACKGROUND: Both vascular inflammation as determined by C-reactive protein (CRP) and extrinsic coagulation as measured by factor VII activity (F VII) may predict clinical restenosis rate in patients with stable angina pectoris undergoing elective percutaneous coronary intervention (PCI). HYPOTHESIS: The primary objective of this study was to investigate the associations between baseline CRP levels, F VII activity, and restenosis rate after elective PCI in a 6-month follow-up period. METHODS: This prospective study included 81 patients aged > or = 19 years undergoing PCI for angiographically significant (> or = 70%) stenosis, with or without stenting, and 49 controls. Factor VII activity and CRP were measured in samples collected at angiography and 16-24 h post procedure after overnight fast. Successful PCI was defined as final diameter of < 50% with TIMI 3 flow and no complication within 1 h. After 6 months all patients who had undergone PCI were evaluated via a standardized questionnaire. Clinical restenosis was defined as the occurrence of a major adverse coronary events (MACE), within the follow-up period. RESULTS: Diagnostic angiography led to a significant increase in CRP levels after 16-20 h in patients with discrete CAD (n = 22) but not in patients without any signs of coronary atherosclerosis (n = 27). During a 6-month follow-up after PCI, 17 of 81 (21%) patients developed MACE. Tertiles of CRP levels independently predicted clinical restenosis, as it developed in 33.3% of patients with the highest CRP levels (0.7-4.8 mg/dl), in 16.6% of patients with second tertile CRP levels (0.23-0.69 mg/dl), and in 7.4% of patients with lowest tertile CRP levels (0.0-0.22 mg/dl). There was a significant difference in the restenosis rate between patients from the first and the third tertiles (p = 0.018). Successful PCI was associated with a significant decrease of mean CRP levels after 6 months, whereas PCI in patients suffering from MACE led to no change in CRP levels. There was no association between factor VII activity and clinical outcome after PCI, and F VII activity did not change over a 6-month period. CONCLUSIONS: In patients with stable angina pectoris undergoing elective PCI, increased preprocedural and 6-month follow-up CRP plasma levels are associated with clinical restenosis. Factor VII plasma activity lacks such correlations.

Adult↗
PubMed2003

Intraoperative angiography for quality control in MIDCAB and OPCAB.

We present our initial experience with intraoperative angiographic evaluation of coronary artery bypass grafts placed on the beating heart. Thirty-three grafts were investigated in 23 patients. Transfemoral angiography was performed using an OEC 9800 mobile C-arm. Spasm of the graft and/or target vessel was present in 11 grafts, two grafts were severely stenosed requiring surgical revision. In a third case an additional bypass graft was placed due to angiography findings. There was no hospital mortality and no significant perioperative myocardial ischemic event. All patients were free of angina 6 months postoperatively. Intraoperative angiography seems to reveal valuable information in beating heart coronary surgery.

Adult↗
PubMed1996

Validation of Automated Border Detection in Intravascular Ultrasound Images.

Intravascular ultrasound (IVUS) imaging provides cross-sectional views of the vessel lumen; however, lumen measurements still rely on operator-dependent border delineation and time-consuming lumen tracings. We tested a new system for automated lumen border detection in IVUS images based on acoustic quantification of blood and vessel wall. In 10 rabbits, 29 segments of the aorta were imaged in vivo using a 2.9-Fr IVUS catheter. IVUS images were obtained during motorized pullbacks of aortic segments of 18 mm length. Automated measurements of lumen dimensions were compared to automated measurements of a second pullback through the same segment, lumen measurements derived from visual border tracings in IVUS images, and to quantitative angiography. The automated system showed good reproducibility: Correlations for repeated measurements of lumen area, maximal and minimal lumen diameters were r = 0.97, r = 0.91, and r = 0.93, respectively. Automated measurements also correlated well to visual image analysis (lumen area, r = 0.97; maximal lumen diameter, r = 0.89; minimal lumen diameter, r = 0.89) and to angiographic measurements (lumen area, r = 0.93; lumen diameter, r = 0.95). In 12% of the images, the automated system overestimated lumen dimensions because of weak wall signals in the presence of echolucent structures next to the wall. Signal artifacts from the IVUS catheter itself or strong blood backscatter resulted in lumen underestimation in 6% of the images. Over- and underestimation of lumen by the border detection system were often associated with eccentric catheter position. Thus, lumen measurements in vivo IVUS images can be performed using an automated border detection system based on acoustic quantification of blood and vessel wall. The system allows reproducible and accurate measurements of lumen area and diameters. (ECHOCARDIOGRAPHY, Volume 13, November 1996)

Journal Article↗