[Operative risk of geriatric patients in cardiac surgery]. / Operatives Risiko geriatrischer Patienten in der Herzchirurgie.

BACKGROUND: Despite substantial progress in interventional cardiology, there are still many geriatric patients who require cardiac surgery. Estimation of the operative risk is therefore of great importance. OBJECTIVE: The prognostic value of the geriatric assessment for estimation of the operative risk was evaluated. MATERIAL AND METHODS: Between 2008 and 2009 a geriatric assessment was carried out on 500 patients before an urgent or elective cardiac surgery intervention. The primary endpoints were in-hospital death, death within 30 days after the intervention and stroke. A secondary endpoint was the combination of death, stroke and in-hospital complications. RESULTS: The average age of the patients was 77.1 ± 4.6 years and 44.3% of the particpants were women. Aortic stenosis was the primary reason for surgery in 49.2% of patients and coronary artery disease in 38.8% of patients. Half of the patients (56.5%) showed functional impairments in one or more evaluated domains. Significant limitations in cognitive function were present in 11.8% and in mobility in 2.4% of the patients. The 30-day mortality was 2.9% and stroke occurred in 1.4% of the patients. After multivariate analysis cognitive impairment remained independently associated with the operative mortality (odds ratio OR 3.8, 95% confidence interval CI 1.2-12.7). CONCLUSION: The perioperative mortality of older patients in cardiac surgery is low. A limited functional status detected in the geriatric assessment is associated with an increased mortality. Impaired cognitive function is an independent predictor of postoperative mortality.

Preexisting atrial fibrillation as predictor for late-time mortality in patients with end-stage renal disease undergoing cardiac surgery--a multicenter study.

BACKGROUND: Although patients with end-stage renal disease (ESRD) are considered to be high-risk patients in cardiac surgery, the reported studies are rather small, resulting in unsatisfactory analyses of outcome determinants. Therefore, we aimed to identify possible risk factors, with a particular focus on the impact of pre-existing atrial fibrillation (AF) on the postoperative short-term and long-term mortality of ESRD patients undergoing cardiac surgery. METHODS: In a multicenter study 522 patients with ESRD undergoing CABG only (62.9 %), valve surgery only (17.2 %), or both (19.9 %) with comparable demographic and other cardiac risk factor characteristics were investigated retrospectively over a period of 10 years. The outcome was divided into perioperative (within 30 days) and late morbidity and mortality, and multivariate analysis was performed for both. RESULTS: The mean perioperative mortality was 11.5 % and the 5-year survival rate was 42 %. Emergency surgery, insulin-dependent diabetes mellitus, the number of vein grafts and age were identified as risk factors whereas complete revascularization, the use of an internal thoracic artery and the presence of sinus rhythm were identified as beneficial factors for long-term survival. 14.1 % of all patients had pre-existing AF. Although AF was not identified as an independent risk factor for perioperative mortality ( P = 0.59), it was identified as an independent predictor for late mortality ( P < 0.001). Median survival of patients without AF was 1816 days, while for patients with AF it was only 715 days. CONCLUSIONS: AF does represent an independent predictor for long-term but not perioperative mortality in patients with ESRD. However, effective treatment of AF is controversially discussed. Anticoagulation therapy or perioperative ablation of the arrhythmia should be considered in order to improve the survival of these patients.

Recombinant hirudin for cardiopulmonary bypass anticoagulation: a randomized, prospective, and heparin-controlled pilot study.

BACKGROUND: Lepirudin, a recombinant hirudin, is a direct acting thrombin inhibitor that has been used as a heparin alternative in patients with heparin-induced thrombocytopenia requiring on-pump cardiac surgery. To evaluate the efficacy, safety, and clinical utility of lepirudin as a cardiopulmonary bypass (CPB) anticoagulant, we compared lepirudin with heparin in a routine CPB setting. METHODS: Twenty patients were randomly assigned to receive lepirudin (0.25 mg/kg b. w. bolus and 0.2 mg/kg b. w. added to the CPB priming) or heparin (400 U/kg b. w. bolus) with protamine reversal. Lepirudin and heparin anticoagulation during CPB was monitored using the ecarin clotting time or ACT, respectively and additional lepirudin (5 mg) or heparin (5000 U) boluses were administered. RESULTS: The CPB circuit was performed in both groups without thromboembolic complications. Median blood loss during the first 36 hours was statistically higher ( P = 0.007) in the lepirudin group (1.226 +/- 316 ml) compared to the heparin group (869 +/- 189 ml). One patient of the lepirudin group developed pulmonary embolism 24 hours after surgery. This patient was tested homozygous for the FV-Leiden mutation. CONCLUSION: Lepirudin provides effective CPB anticoagulation but induces a higher postoperative blood loss than heparin. Lepirudin should be restricted to patients undergoing CPB who cannot be exposed to heparin.

Lepirudin for cardiopulmonary bypass surgery in a patient with terminal renal insufficiency and acute heparin-induced thrombocytopenia.

A patient with triple heart valve disease, heparin-induced thrombocytopenia, and terminal renal insufficiency was treated successfully using lepirudin for anticoagulation of cardiopulmonary bypass (CPB) and during the postoperative course. Anticoagulatory monitoring was performed with ecarin clotting time during CPB and aPTT postoperatively.

Pulmonary embolism after cesarian section due to heparin-induced thrombocytopenia despite normal platelet count.

Heparin-induced thrombocytopenia (HIT) type II is typically characterized by a decrease in platelet count to values between 20 and 120 x 10 (9)/L or a platelet count fall of greater than 50%. We report on a patient who developed a HIT syndrome, thrombosis of the vena cava, and fulminant pulmonary embolism during heparin treatment after cesarean section, without a significant decrease in platelet count. Lepirudin anticoagulation and ecarin clotting time (ECT) monitoring were used successfully during cardiopulmonary bypass.

Correction of congenital heart defects and mitral valve operations using limited anterolateral thoracotomy.

PURPOSE: Median sternotomy, which generally is used as a standard access for atrial septal defect (ASD) and mitral valve operations, has a significant risk of postoperative instability/osteomyelitis of the sternum. Moreover, especially in young women, the resulting large scar is a poor cosmetic result that may have adverse psychological consequences. Our presentation suggests that these difficulties may be avoided by the use of a less invasive approach consisting of a limited anterolateral thoracotomy with standard cannulation. MATERIAL AND METHODS: From June 1997 until December 1999, 13 women, mean age 31.9 +/- 9.2 years, with atrial septum defect (n = 8), sinus venosus defect with partial anomalous pulmonary venous connection (n = 1), left atrial myxoma (n =1) or mitral valve regurgitation (n = 3), were scheduled for less invasive operation. In all cases a double lumen tube was used for ventilation. After a submammarian skin incision of about 10 cm a limited anterolateral thoracotomy was performed in the fifth right intercostal space. For cannulation of the ascending aorta a trochar cannula was used. Both caval veins were cannulated by angled vena cava catheters. Standard cardiopulmonary bypass was established using normothermia in all patients undergoing operations with correction of congenital heart defects and mild hypothermia (32 degrees C) in the three patients undergoing mitral valve operation. Surgery was performed in cardioplegic arrest using Bretschneider's solution. All corrections of congenital heart defects were performed by Goretex patches. Mitral valve reconstruction was carried out in two patients, and one patient underwent mitral valve replacement. RESULTS: No complications occurred in any of the 13 patients peri- or postoperatively. Total time of operation was 211.9 +/- 36.0 minutes, the perfusion time was 77.0 +/- 25.8 minutes, and the aortic cross-clamp time was 51.8 +/- 21.9 minutes. Mean stay in ICU was 1.2 +/- 0.4 days (total hospital stay: 7.8 +/- 2.2 days). Postoperative thoracic x-ray and cardiac echocardiography/dopplersonography revealed no pathological findings in any patients. CONCLUSION: Atrial septal defect operations, including partial anomalous pulmonary venous connection, left atrial myxoma and mitral valve operations, can be performed safely and effectively using a limited anterolateral thoracotomy and standard cannulation technique with excellent cosmetic results.

Clinical outcome of patients with and without renal impairment undergoing a minimally invasive LIMA-to-LAD bypass operation.

PURPOSE: Patients with renal impairment undergoing conventional coronary artery bypass grafting (CABG) have a significant risk of postoperative deterioration of kidney function. We investigated the outcome of patients with and without renal impairment treated by off-pump coronary artery surgery. METHODS: From January 1997 until January 2000, 158 consecutive patients (mean age 63 +/- 9.8 years, 126 male, 32 female) underwent minimally LIMA-to-LAD bypass operations. The patients were divided into three groups: group I patients (n = 133) had a preoperative creatinine of < 1.3 mg/dL, group II patients (n = 21) had a creatinine of > 1.3 mg/dL, and patients of group III (n = 4) required chronic dialysis due to terminal kidney dysfunction. Monitoring of the blood creatinine was performed during the entire hospital stay. A postoperative angiogram was performed in 113 of the 158 patients. RESULTS: All operations were performed without intraoperative complications. Postoperative angiograms revealed a patent LIMA-to-LAD bypass in all but one patient, who demonstrated a dissection of the left internal mammary artery (LIMA) graft. Mean creatinine value on admission was 1.0 +/- 0.1 mg/dL in group I and 2.7 +/- 1.9 mg/dL in group II. The maximal postoperative creatinine value was 1.1 +/- 0.4 mg/dL in group I and 2.9 +/- 2.7 mg/dL in group II. Neither hemofiltration nor hemodialysis was necessary in any patient of group I or group II during the postoperative course. CONCLUSION: Minimally invasive LIMA-to-LAD bypass is a safe and effective procedure with low morbidity and no mortality in the first 158 patients. Preoperative renal impairment had no adverse effect on outcome or residual kidney function. Thus, higher doses of diuretics and hemofiltration/dialysis were not used, resulting in a cost reduction. Therefore, this approach may be worthwhile to consider in patients with significant renal impairment who have to undergo CABG.

A new method for coronary occlusion and local stabilization during minimally invasive LIMA-to-LAD-bypass.

The minimally invasive direct coronary occlusion and stabilizing technique (midCOAST)-system, a new device for coronary occlusion and local stabilization during minimally invasive LIMA-to-LAD-bypass is presented. A closed platform with an oval opening in its center provides optimal immobilization together with platform-fixed vessel-loops, which are used for LAD-occlusion. Clinical results in 72 consecutive patients indicate that the midCOAST-device can be safely and effectively used for minimally invasive LIMA-to-LAD-procedure, even in patients with impaired left ventricular function. Due to the optimal immobilization of the target area the quality of the LIMA-to-LAD-anastomosis, documented by post-operative angiography (62/72), was excellent in all cases.

Beating heart operations including hybrid revascularization: initial experiences.

BACKGROUND: The outcome of patients (n = 45) with coronary one- to three-vessel disease undergoing beating heart operations using a recently developed stabilizing device was investigated. METHODS: Left internal mammary artery-to-left anterior descending coronary artery (LIMA-to-LAD) revascularization was carried out alone (n = 31) or as hybrid procedure in combination with a balloon angioplasty (n = 14). RESULTS: All 45 patients underwent a successful LIMA-to-LAD procedure without intraoperative complication during a 21 +/- 8-minute (range, 10 to 53 minutes) LAD occlusion time. In 14 hybrid procedures a total of 19 stenoses including 3 left main stenoses were treated successfully by percutaneous transluminal coronary angioplasty and stenting. The postoperative courses were uneventful with the exception of two surgical reexplorations necessitated by bleeding. No worsening of renal, neurologic, or respiratory functions occurred in any patient. In the group having a single LIMA-to-LAD procedure, early postoperative coronary angiograms (22 of 31) showed a patent LIMA graft and excellent anastomosis; this was also true in 4 patients 12 months after operation as shown in angiograms. All patients undergoing hybrid revascularization demonstrated a patent LIMA-to-LAD anastomosis; in 1 patient there was a dissection in the midlevel of the LIMA, which was stented successfully. The 6-month follow-up angiograms in 7 of 14 patients revealed open LIMA bypass grafts in all patients except 1, who was stented because of dissection. CONCLUSIONS: These data indicate that a beating heart operation including hybrid revascularization is safe and effective in selected patients with coronary one- to three-vessel disease including left main stenosis. This approach may be especially advantageous in comparison with conventional coronary artery bypass grafting in patients with severe concomitant disease.

Recombinant hirudin as an anticoagulant during cardiac operations: experiments in a pig model.

OBJECTIVE: The efficacy and safety of recombinant hirudin (r-hirudin) compared with heparin as an anticoagulant during open-heart surgery has been studied in a pig model. METHODS: A total of 18 Göttingen minipigs were randomly divided into three treatment groups and subjected to cardiopulmonary bypass for 1 h. Heparin-treated animals received a bolus of unfractionated heparin of 400 IU/kg body weight. Recombinant hirudin was given by a bolus injection of 1 mg/kg body weight, followed by a 1 h lasting infusion of 1 mg/kg body weight per h. The heparin-anticoagulated animals and one group of the hirudin-treated animals additionally received aprotinin at a dosage of 17500 KIU/kg body weight (KIU, kallikrein inhibitory units). In the second group of r-hirudin-treated animals, the aprotinin was replaced by saline. RESULTS: The extracorporeal circuit remained patent for a 1 h pump period in all of the animals studied. There was no evidence of vascular occlusion or clot formation in the r-hirudin-treated animals. The anticoagulant efficacy of the hirudin protocol used is further demonstrated by the results of electron-microscopical scans of the pump-line filters. Fibrin deposits were visible only in the heparin-treated animals and not in r-hirudin-treated pigs. Despite this strong anticoagulant effect, there was no evidence of an increased bleeding tendency in r-hirudin-treated pigs. Moreover, histological studies showed a statistically significant (P < 0.05) higher incidence of tissue bleeding in the heparin/aprotinin-treated animals compared with the r-hirudin/aprotinin-treated pigs. Studying the platelet function, a statistically significant (P < 0.01) better preserved ADP- and collagen-induced platelet aggregation was seen in the r-hirudin/aprotinin-treated animals when compared with heparin/aprotinin-treated animals. CONCLUSIONS: These data demonstrate that r-hirudin can be used successfully as an alternative anticoagulant to heparin during cardiac operations including cardiopulmonary bypass. The better preservation of platelet function suggests that r-hirudin may reduce the postoperative risk of bleeding.

Amplification of resistance genes in Haemophilus influenzae plasmids.

Intramolecular amplification produces tandem repeats of tetracycline and combined tetracycline-chloramphenicol resistance determinants in conjugative plasmids of Haemophilus influenzae. This process depends on host recombination pathways. Physical mapping revealed the tetracycline transposon involved in amplification to be almost identical with Tn10, including two IS10 insertion elements. The chloramphenicol resistance determinant of the combined transposon is 1.9 kilobases (kb) in size and is bound by two 1.3-kb inverted repeats. Insertion in the close vicinity of the inside end of the left-hand IS10 generates a deletion of a 1.6-kb Tn10 region. The amplifiable units were resolved to comprise not only the respective resistance transposons, but also an additional 1.6-kb sequence (designated AS) which was demonstrated to be identically present in the different amplification systems studied. AS separates amplified transposons from each other, thereby maintaining the same orientation. Moreover, AS is present at the left flank of the transposons, but is missing at the right one. It was shown that AS represents a general constituent of the H. influenzae plasmids of the 45-kb class. Evaluation of the results suggests that AS is responsible for the recombinational events involved in the gene amplification process.

Origin of Haemophilus influenzae R factors.

The Haemophilus influenzae R plasmids specifying resistance against one, two, or three antibiotics which have emerged in different parts of the world were shown to have closely related but not identical plasmid cores. The gene for ampicillin resistance in the H. influenzae plasmid pKRE5367 is part of a transposon similar to Tn3, which was transposed from pKRE5367 onto RSF1010 in Escherichia coli. An indigenous H. influenzae plasmid (pW266) was isolated. Its properties correspond to those of the H. influenzae R plasmids, except for the presence of a drug resistance transposon. The in vitro-generated H. influenzae R plasmids carrying an ampicillin resistance transposon, a tetracycline resistance transposon, and a transposon for combined tetracycline-chloramphenicol resistance resembled the natural isolates. The findings support the hypothesis that the R plasmids of H. influenzae are of multiclonal evolutionary origin.