Retrograde internal mammary artery as coronary bypass. A prospective study with postoperative angiographic evaluation.

Although the internal mammary artery (IMA) as a coronary graft offers better long-term patency than the saphenous vein, a factor limiting its use has been the length of the artery's pedicle. In an attempt to overcome this limitation, we evaluated the use of retrograde right IMA in a prospective study. In ten patients scheduled for routine coronary artery bypass surgery, bilateral IMA grafting was used, the left IMA in routine fashion, but the right IMA dissected from the level of the first rib, cut there and placed as an inverted graft. Three months postoperatively the patients were clinically evaluated with stress exercise test (n = 10) and coronary angiography (n = 9). No patient had recurrence of angina. Angiography revealed patency of the retrograde right IMA graft in six of nine patients. On the basis of these data we do not recommend routine use of retrograde IMA.

The CarboMedics valve: midterm follow-up with analysis of risk factors.

BACKGROUND: This study examined the midterm results with the CarboMedics prosthetic valve. METHODS: From 1987 through 1991 a total of 569 patients received the CarboMedics prosthesis. RESULTS: Early mortality was 4.9% and related to emergency operation, presence of diabetes mellitus, coronary artery disease, preoperative New York Heart Association class, duration of cardiopulmonary bypass, and aortic cross-clamp time. Midterm follow-up with respect to mortality was 100% complete. All patients were followed up in the hospital after 1 year. In addition 86% of the patients responded to a questionnaire. Mean follow-up was 3 years (range, 0 to 5.6 years). Cumulative survival at 1 and 4 years was 91.2% +/- 1.2% and 83.7% +/- 1.8%, respectively. Five patients experienced obstructive valve thrombosis (0.3%/patient-year), 16 patients had major thromboembolic events (0.9%/patient-year), and 10 patients had major warfarin-related bleeding (0.6%/patient-year) requiring hospitalization or blood transfusions. Eight patients were reoperated on for paraprosthetic leak (0.4%/patient-year). Prosthetic valve endocarditis developed in 4 patients (0.2%/patient-year). No structural valve failure was observed. CONCLUSIONS: Midterm follow-up demonstrates that the CarboMedics mechanical prosthesis is reliable and has an acceptable rate of valve-related complications.

Risk factors for early and late mortality in surgical treatment of coronary artery disease.

A total of 1025 patients who had coronary bypass surgery at the Surgical Department A, Rikshospitalet, Oslo, between 1982 and 1986, were analysed for factors associated with early mortality and long-term survival. The cumulative follow-up time accounted for 6553 patient-years; the median follow-up was 6.45 years and ranged from the day of admission to 10 years. In total, 31 patients (3%) died within 30 days of surgery. Some 30 possible risk factors were analysed. Univariate analysis followed by a multivariate analysis defined six independent risk factors for early mortality. These were lack of sinus rhythm, previous heart surgery, mitral regurgitation, left main stem stenosis, unstable angina, and an elevated left ventricular end-diastolic pressure. Estimation of attributable risk showed that these factors could identify all patients who died early. Independent risk factors for late death were: lack of sinus rhythm, resection of a left ventricular aneurysm, left main stem stenosis, New York Heart Association (NYHA) class IV on admission, an elevated end-diastolic pressure, and prolonged cross-clamping time. The attributable risk analysis showed that independent risk factors for total mortality explained only about half of the patients who died. This appeared to be because of the competing effect of non-cardiac mortality. Results of the study show that risk factors for early mortality are good indicators for the outcome of coronary artery bypass surgery, identifying all deaths, whereas long-term mortality cannot be predicted. Stratification of independent risk factors allows a better comparison of mortality in different centres, and also better quality control of bypass surgery.

Pericardio-peritoneal window for recurrent postoperative effusion. Case report.

A pericardio-peritoneal window was created to relieve cardiac tamponade by recurrent effusion after heart transplantation. The effect was echocardiographically evaluated. The technique is described. It requires no sternal splitting for pericardial access and no foreign materials such as drains or shunts. The method should be considered for immunologically compromised, infection-prone patients with heart transplantation.

Complement activation during extracorporeal circulation. In vitro comparison of Duraflo II heparin-coated and uncoated oxygenator circuits.

The degree of complement activation during cardiopulmonary bypass is considered a valuable parameter of biocompatibility of the extracorporeal circuit. In an in vitro setting with a heart-lung machine primed with fresh whole blood and saline solution, the C3 activation products C3b, iC3b, and C3c and the terminal complement complex were measured in double-antibody enzyme immunosorbent assays. No differences were found between seven sets treated with Duraflo II heparin coating and seven uncoated sets after 2 hours of circulation. C3 activation products (expressed as median and 95% confidence intervals) increased from 4.5 AU (2.8 to 12.3 AU) to 16.5 AU (10.0 to 19.4 AU) in the uncoated sets (p = 0.02) and from 4.6 AU (2.2 to 5.8 AU) to 19.3 AU (3.5 to 27.1 AU) in the coated sets (p = 0.02). Terminal complement complex increased from 5.7 AU (2.7 to 11.3 AU) to 13.6 AU (8.2 to 17.8 AU) in the uncoated sets (p = 0.02) and from 7.9 AU (4.6 to 11.4 AU) to 17.3 AU (9.4 to 35.1 AU) in the coated sets (p = 0.02). A significant drop in thrombocyte levels was observed in both coated and uncoated sets. In a supplementary series, the sterilization process did not influence the results. Although Duraflo II heparin coating is considered highly effective in preventing coagulation, it did not prevent complement activation in the present in vitro study. We hypothesize that the mode by which the heparin molecule is bound to the surface may be essential to obtain effects on both coagulation and complement system.

Aortic valve replacement four years after cardiac transplantation.

Severe aortic insufficiency developed in a 56-year-old woman 4 years after cardiac transplantation. Aortic valve replacement was performed with insertion of a 23 mm Carbo Medics mechanical prosthesis. The patient recovered completely and is, 5 months after valvular replacement, in New York Heart Association functional class I.

Cyclosporine A monitoring in patients with renal, cardiac, and liver transplants: a comparison between fluorescence polarization immunoassay and two different RIA methods.

In the present study a new method for selectively determining parent cyclosporine (CsA) in whole blood, a fluorescence polarization immunoassay (FPIA; TDx Abbott), was compared with a RIA method (Sandimmun, Sandoz Ltd, Basle, Switzerland). A total of 974 samples were collected during the first 3 post-operative months from 63 renal, cardiac, and liver transplant recipients. The CsA concentrations measured with FPIA ranged from 14% to 19% above RIA (specific) in the middle ranges. Regression equations in renal transplants: FPIA = 1.001 x RIA + 28; in heart transplants: FPIA = 1.08 x RIA + 27 and in liver transplants: FPIA = 1.13 x RIA + 13. Considering the improved precision of the new method (inter-assay CV with FPIA: 3.8-9.5%; with RIA: 18.6%), the slightly lower specificity will usually be of minor importance in the therapeutic range for whole blood CsA concentrations following organ transplantations. The FPIA measurements which deviated most from the regression line compared with RIA-specific CsA values, tended to coincide with high CsA concentrations or rather extreme RIA specific to RIA non-specific ratios. In addition to analytical imprecision with the RIA-specific method, lower specificity of the FPIA vs. some of the metabolites may explain these deviations. The majority of these observations occurred as isolated episodes with normal relationship between RIA specific and FPIA on preceding and following days. Accordingly large dosage adjustments should await verification in repeated samples. Following these precautions the FPIA method may prove useful and safe in the monitoring of cyclosporine treatment.

Single lung transplantation. Morphological surveillance by transbronchial biopsy.

Seven cases of single lung transplantation are reported. The recipients were all below 60 years of age and severely disabled with end-stage lung disease. Transplantation was performed according to ABO blood group compatibility and negative lymphocytotoxic cross-match between donor and recipient irrespective of HLA mismatch. Recipients' diagnoses were sarcoidosis (3), alfa-1 antitrypsin deficiency (3), and idiopathic emphysema (1). Mean recipient age was 48 +/- 2.4 years (range 45-52). Donor age was 29.7 +/- 5.6 years (range 16-49). The immunosuppressive regimen included cyclosporin A, azathioprine, steroids and rabbit antithymocyte globulin. Excellent graft function was achieved. Six patients survived the postoperative period and are alive 4-18 months posttransplant. One patient died after the operation due to pneumonia with respiratory distress syndrome. Graft function was also monitored by transbronchial biopsy, and 57 biopsy procedures were performed without fatal complications. Acute cellular rejection was seen in 16 biopsy specimens from 5 recipients (grade 1 and 2 rejection in 14, grade 3 rejection in 2). Neither severe rejection with septal necrosis (grade 4) nor obliterative bronchiolitis was seen. The rejection rate was 0.03 episodes per patient/month. In contrast to other reports, episodes of cellular rejection occurred throughout the observation period, and were not mainly limited to the first 4 months posttransplant. Graft vascular occlusive disease or chronic vascular rejection was found in 6 biopsy specimens from one recipient. Five patients experienced 7 episodes of cytomegalovirus infection. The cytomegalovirus infection rate was 0.01 episodes per patient/month. The incidence of infection was significantly lower compared to previous studies of rejection in other lung graft combinations. Both infections and rejection episodes may contribute to the development of obliterative bronchiolitis. Almost one third of the specimens (30%) showed lymphocytic bronchitis without perivascular inflammation. The absence of perivascular infiltrates and exclusion of infectious agents leaves in question the aetiology of this inflammation. The lymphocytic bronchitis could be ischaemic, related to aspiration, or represent recurrent sarcoidosis, or, in fact, express bronchial rejection. All biopsy specimens regarded as rejection with cellular infiltrates in the lung parenchyma also showed a lymphocytic bronchitis. The impact of HLA mismatch on cellular and vascular rejection is unclear. Transbronchial biopsy is a reasonably safe and reliable method in the diagnosis of rejection and infection in single lung transplantation.

Surgical intervention following failed percutaneous coronary angioplasty.

Percutaneous transluminal coronary angioplasty (PTCA) was performed on 725 occasions at the National Hospital of Norway in 1981-1990. Acute surgical intervention was necessary within 24 hours after PTCA in 15 cases, on indications that included coronary artery dissection (8 cases) and acute thrombotic occlusion (5). Electrocardiographic signs of ischemia were present in 11 patients with anginal pain, while two had severe angina but normal electrocardiogram. Two patients had a non-ischemic indication for surgery. Despite surgery, ten of the 15 patients had acute myocardial infarction. One of the ten died. At follow-up nine of 12 patients were free from angina and three had recurrent symptoms.

Morbidity risk factors in human cardiac transplantation. Histoincompatibility and protracted graft ischemia entail high risk of rejection and infection.

Data from the first 103 human heart transplantations performed on 100 recipients (aged 14-62 years) at a single center from November 1983 to January 1990 were analyzed in order to detect morbidity-causing risk factors. Cumulative one- and five-year graft survival was 82% and 68%. Multivariate analysis revealed three independent risk factors for early rejection, viz. HLA-DR and HLA-B mismatches and no prior cardiac surgery. Graft ischemic time exceeding 71 min was an independent risk factor for rejection, especially for moderate or severe events, and for infection. HLA-DR mismatch was an independent risk factor for moderate and severe rejection events and for infections. Finally, patients operated on because of end-stage ischemic heart disease were at significantly higher risk of rejection than those with other cardiac disorders. The study has several implications: Prospective tissue typing for cardiac transplantation and selection of donors may have an impact on graft function: Damage to the graft by prolonged ischemia may be reduced by improved organ preservation.

Patency of the internal mammary artery used as sequential graft.

In 28 patients with the left internal mammary artery (IMA) used as a sequential coronary artery graft, clinical and angiographic evaluation was made 19-47 months postoperatively. Patency was 96% in the proximal anastomoses and 93% in all the anastomoses. Angiography, however, showed optimal function in only 75% of the distal graft ends. These observations indicate that routine use of left IMA as a sequential graft should be restricted to experienced surgeons. Clinical and angiographic findings did not always correlate, emphasizing that evaluation of IMA-graft patency should include angiography.

Hemodynamic evaluation of the CarboMedics prosthetic heart valve in the aortic position: comparison of noninvasive and invasive techniques.

Seventy-three patients with a CarboMedics aortic bileaflet valve prosthesis were examined by Doppler ultrasonography, and 27 of them were also assessed by transseptal catheterization. The ultrasonic mean systolic gradient was 17.1 +/- 5.6 mm Hg for valve size 19 mm, falling gradually with increasing valve size to 6.8 +/- 2.5 mm Hg for size 27 mm. The catheter mean systolic gradient was consistently smaller than the ultrasonic gradient (4.3 +/- 4.8 mm Hg), but Tobit regression analysis showed a significant association between the two methods. In all patients both methods revealed negligible to small amounts of retrograde leakage, which is assumed to be a normal finding for this valve. The effective flow areas of the valves calculated from the ultrasonic data were similar to the in vitro calculated flow areas. The hemodynamic potential of this valve is therefore completely utilized in vivo. The effective orifice area corrected for body surface area increased with increasing valve size, which demonstrates a moderate valve-patient mismatch.

Effects of chronic amiodarone treatment on human myocardial beta adrenoceptor density and adenylate cyclase response.

STUDY OBJECTIVE: The aim of the study was to evaluate the effect of chronic treatment by amiodarone on beta adrenoceptor density and adenylate cyclase response in human myocardium. DESIGN: Density of beta 1 and beta 2 adrenoceptors was measured by radioligand binding assay. beta Adrenoceptor stimulated production of cAMP was measured by adenylate cyclase assay. EXPERIMENTAL MATERIAL: Right auricular tissue from five patients on chronic amiodarone treatment was compared with that from nine patients in similar clinical and haemodynamic state undergoing coronary bypass surgery. MEASUREMENTS AND MAIN RESULTS: beta 1 and beta 2 adrenoceptor subtypes were quantified using the highly beta 1 selective antagonist Sandoz 204 545. The total beta adrenoceptor density was 28% lower in the amiodarone treated group than in the controls (42.0 v 58.3 fmol.mg-1 protein, p less than 0.02), beta 1 adrenoceptors were 25% lower (33.1 v 44.3 fmol.mg-1 protein, p less than 0.02), and beta 2 adrenoceptors were 36% lower (8.9 v 14.0 fmol.mg-1 protein, p less than 0.02). The cAMP production following non-selective beta adrenoceptor stimulation (isoprenaline 5 mumol.litre-1) was reduced by 38% in the amiodarone treated group (14.2 to 8.7 pmol.min-1.mg-1 protein, p = 0.05). Terbutaline stimulated cAMP production was reduced by 49% (8.3 to 4.3 pmol.min-1.mg-1 protein, p = 0.03). Fluoride stimulated cAMP production was not significantly different (9.4 v 8.4 pmol.min-1.mg-1 protein, p = 0.15). CONCLUSIONS: Chronic treatment with amiodarone is associated with a non-selective downregulation of beta adrenoceptors. beta Adrenoceptor stimulated cAMP production was also reduced. The "beta blocking effect" of amiodarone is probably related to downregulation of beta adrenoceptors.

Intrapericardial left atrial aneurysm diagnosed by transoesophageal echocardiography and nuclear magnetic resonance imaging.

A case of intrapericardial left atrial aneurysm is described in a 38-year-old woman, who presented with invalidating paroxysmal atrial fibrillation. The diagnosis was suspected by 2D-echocardiography, and confirmed by transoesophageal echocardiography and magnetic resonance imaging. Chest X-ray, right and left ventricular and coronary angiography were normal. The aneurysm was surgically removed, and the patient has subsequently remained free from symptoms.

[Results of 6 1/2 years of heart transplantation at Rikshospitalet]. / Resultater med hjertetransplantasjon ved Rikshospitalet etter 6 1/2 år.

We discuss our experience from 6 1/2 years of orthotopic heart transplantation at Rikshospitalet (the National Hospital). 112 grafts were performed on 109 patients (19 women and 90 men), mean age 47 years (range 14-63). In the first nine patients the immunosuppressive regimen consisted of cyclosporine A and prednisolone, and in the last 100 azathioprine was added (triple medication). There was no operative mortality. 21 patients died, giving an 81% cumulative survival, with a significantly better prognosis among those who received triple immunosuppressive regimen. The main complications were rejection, infection and arrhythmia. Since our main problem was rejection it is concluded that careful supervision, concentrated on as few cardiologists as possible, and a liberal indication for myocardial biopsy, are decisive for the prognosis.

[Single lung transplantation as treatment of terminal lung diseases]. / Transplantasjon av en lunge som behandling av terminal lungesykdom.

The article describes the first cases of single lung transplantation in Norway. The indication for surgery was end-stage pulmonary disease (1 sarcoidosis, 2 emphysema) in three severely disabled patients requiring administration of oxygen. The operation necessitated cardiopulmonary bypass in all patients. Primary graft function was excellent. Epidural analgesia, peripheral pulse oxymetry and continuous monitoring of mixed venous oxygen saturation aided early extubation. The initial postoperative course with a four drug immunosuppressive regimen has been encouraging. Rejection is monitored by clinical examination, chest x-ray, serial pulmonary function tests and transbronchial biopsies.

Risk factors for total and cause-specific mortality in human cardiac transplantation. Prolonged extracorporeal bypass time: a high risk factor for rejection and infection.

Data from the first 103 human heart transplantations in 100 recipients performed at a single centre from November 1983 to January 1990 were analysed to detect risk factors for overall and cause-specific mortality. Twenty-two patients died. Cumulative 1 year graft survival was 82% and 5 year, 68%. Acute and chronic rejection was the cause of death in 9 patients, disseminated infection in 8 and cancer in 3. One patient died from cerebral haemorrhage and 1 from acute cardiac failure. The mean observation time was 803 days (range: 1-2 308 days). Total follow-up was 226.6 graft years. Risk factors were analysed by univariate and multivariate methods. The type of immunosuppression regimen and recipient age above 50 years were independent risk factors for mortality. Histocompatibility mismatching (HLA-DR) and type of immunosuppression were independent risk factors for lethal rejection and a female recipient was an independent risk factor for lethal infection. Prolonged time on extracorporeal bypass was an independent risk factor for both lethal rejection and infection, and also for overall mortality. The impact of extracorporeal bypass time on rejection and infection is discussed, and the importance of prospective HLA matching in heart transplantation is stressed. The association between recipient female sex and infection remains uncertain.

Heart transplantation in patients with severe pulmonary hypertension and increased pulmonary vascular resistance.

Irreversibly increased pulmonary vascular resistance is a contraindication for cardiac transplantation. At our hospital patients referred for recipient evaluation with systolic pulmonary artery pressure greater than 50 mmHg and pulmonary vascular resistance greater than 2 Wood units (Wu) are tested with intravenous sodium nitroprusside for reversibility. In 23 patients whose increased systolic pulmonary artery pressure (67.4 +/- 10.4 mmHg) and resistance (4.8 +/- 2.4 Wu) were reduced by nitroprusside, orthotopic heart transplantation was performed without early mortality. Right heart catheterization after transplantation revealed a significant and persistent fall of the elevated pulmonary artery pressure and pulmonary vascular resistance. We conclude that if severe pulmonary hypertension and elevated pulmonary vascular resistance are reversible with nitroprusside, the patient can safely undergo heart transplantation.