Feasibility of self-directed learning in clerkships.

BACKGROUND: Self-directed learning has been well described in preclinical settings. However, studies report conflicting results when self-directed initiatives are implemented in clinical clerkships. AIM: To explore the feasibility of self-directed learning stimulated by clinical encounter-cards (CECs) in clinical clerkships. METHODS: Two focus groups of year-four and year-five students were interviewed about the usefulness of CECs to their learning in clerkships. The CECs were then introduced in two cohorts of 248 year-four and 250 year-five medical students and evaluated on a nine-point scale with regard to usefulness and feasibility. RESULTS: The pilot groups reported that the CECs had positive effects in terms of engaging in diagnostic reasoning, reflection on management plans, and professional identity formation. However, the two large cohorts of students rated the usefulness of the CECs on learning in clerkship low (year-four: mean 2.92, SD 1.54; year-five: mean 2.28, SD 1.06) along with preceptor support (year-four: mean 2.68, SD 1.62; year-five: mean 2.59, SD 1.78, p = 0.34). CONCLUSION: Self-directed CECs can have a positive effect on participation and clinical reasoning but are highly dependent on the context of use. Self-directed learning initiatives that aim to increase participation in communities of practice may not be feasible without major faculty development initiatives.

Increased cardiac BNP expression associated with myocardial ischemia.

Congestive heart failure is accompanied by increased cardiac brain natriuretic peptide (BNP) gene expression with elevated plasma concentrations of BNP and its precursor, proBNP. We investigated if myocardial ischemia in the absence of overt heart failure may be another mechanism for increased myocardial BNP expression. The BNP expression was examined in hypoxic myocardium of patients undergoing coronary bypass grafting surgery, in patients with coronary artery disease and normal left ventricular function undergoing percutaneous transluminal intervention therapy, and in heart failure patients without coronary artery disease. BNP mRNA was quantified by real-time PCR, and plasma BNP and proBNP concentrations were measured with radioimmunoassays. Quantitative analysis of BNP mRNA in atrial and ventricular biopsies from coronary bypass grafting patients revealed close associations of plasma BNP and proBNP concentrations to ventricular, but not atrial, BNP mRNA levels. Plasma BNP and proBNP concentrations were markedly increased in patients with coronary artery disease but without concomitant left ventricular dysfunction. These results are compatible with the notion that myocardial ischemia, even in the absence of left ventricular dysfunction, augments cardiac BNP gene expression and increases plasma BNP and proBNP concentrations. Thus, elevated BNP and proBNP concentrations do not necessarily reflect heart failure but may also result from cardiac ischemia.

Electric impedance for evaluation of body fluid balance in cardiac surgical patients.

OBJECTIVE: To evaluate whether electric impedance can be used to monitor body fluid balance and fluid distribution in cardiac surgical patients. DESIGN: Prospective clinical study. SETTING: Heart Center, Rigshospital, Copenhagen. PARTICIPANTS: Sixteen consecutive patients scheduled for cardiac surgery. MEASUREMENTS AND MAIN RESULTS: Body weight, fluid balance, central hemodynamics, and total and segmental body impedance were examined perioperatively. During semisupine rest before surgery, changes in impedance indicated relocation of fluid from the legs to the thorax, mostly in the extracellular space. After surgery, weight and fluid balance increased by 3.87 +/- 0.35 kg and 1.86 +/- 0.16 L (mean +/- SE, p < 0.01) and remained elevated through the next 2 days. Impedance decreased by 30% over the thorax, by 24% over the abdomen, by 2% over the leg, and by 4% over the entire body. Changes in total and thoracoabdominal impedances had the highest correlation to the fluid balance (r = -0.86 and r = -0.87). After correction of impedance values by the constant from the regression model, the mean difference in estimation of fluid changes obtained by electric impedance and by fluid balance was 0 +/- 0.1 L at the range of changes of 4.6 L. CONCLUSION: Alterations in electric impedance closely follow changes in fluid balance during the perioperative period. This method can be used in clinical practice to control postoperative body fluid balance in cardiac surgical patients.

[Heart transplantation]. / Hjertetransplantation.

In carefully selected patients with end-stage heart failure heart transplantation has developed from an experimental procedure to standard therapy during the last 30 years. It is currently accepted as a procedure for prolonging life and also for improving quality of life. According to the Registry of the International Society for Heart and Lung Transplantation the overall one-year actuarial survival is 79% and 10-year survival barely 50%. Nine years after the start of the Heart Transplant Program at Rigshospitalet the overall actuarial survival of 157 consecutive patients is 66%. Due to the limited donor access a decline of heart transplant recipients has been recorded during the late nineties. Mechanical replacement of the heart may develop from technological advances and possibly this therapy may gain a complementary status in heart failure, however the human biological replacement is currently the standard.

[DANAMI. A Danish study of invasive versus conservative treatment of patients with post-infarction ischemia who had received thrombolytic therapy]. / DANAMI. En dansk undersøgelse af invasiv versus medicinsk behandling af trombolysebehandlede patienter med postinfarkt iskaemi.

INTRODUCTION: To compare an invasive strategy employing percutaneous transluminal coronary angioplasty (PTCA) or coronary artery by-pass grafting (CABG) with a medical strategy in patients who had received thrombolytic treatment for first acute myocardial infarction (AMI), and with signs of inducible ischaemia. METHODS: In a prospective study 1008 patients were randomized, 503 to invasive treatment, of whom 266 (52.9%) had PTCA, and 147 (29.2%) CABG, 505 to conservative treatment, of whom eight (1.6%) were revascularized within two months. RESULTS: After a median follow-up of 2.4 years the mortality in the invasive group was 3.6% vs. 4.4% (p = 0.45) in the conservative group, re-infarction incidence was 5.6% vs. 10.5% (p = 0.0038) and percentage of admissions with unstable angina was 17.9% vs. 29.5% (p < 0.00001). DISCUSSION: We conclude that post-infarct patients with inducible ischaemia should be referred to coronary angiography and revascularised accordingly.

Health related quality of life after conservative or invasive treatment of inducible postinfarction ischaemia. DANAMI study group.

OBJECTIVE: To assess health related quality of life in patients with inducible postinfarction ischaemia. DESIGN: A questionnaire based follow up study on patients randomised to conservative or invasive treatment because of postinfarction ischaemia. SETTING: Seven county hospitals in eastern Denmark and the Heart Centre, National University Hospital, Copenhagen, Denmark. PATIENTS: 113 patients with inducible postinfarction ischaemia: 51 were randomised to conservative treatment and 62 to invasive treatment. Average follow up time was three years (19-57 months). MAIN OUTCOME MEASURES: SF-36, Rose angina and dyspnoea questionnaire, drug use, lifestyle, and cognitive function. RESULTS: Invasively treated patients scored better on the SF-36 scales of physical functioning (p = 0.03) and on role-physical (p = 0.04) and physical component scales (p = 0.05) and took significantly less anti-ischaemic drug treatment. Angina occurred in 18% of the invasively treated patients and 31% of the conservatively treated patients (p = 0.09). However, more invasively treated patients suffered from concentration difficulties (18% v 4%; p = 0.04). CONCLUSIONS: Patients who were treated invasively had better health related quality of life scores in the physical variables compared with conservatively treated patients. However, a larger proportion of invasively treated patients had concentration difficulties.

Myocardial perfusion scintigraphy as a screening method for significant coronary artery stenosis in cardiac transplant recipients.

BACKGROUND: Several studies have explored the feasibility of using myocardial perfusion imaging to detect allograft vasculopathy after heart transplantation. We undertook the present prospective consecutive study to comparatively evaluate the role of serial myocardial perfusion single-photon emission computed tomography (SPECT) scanning and coronary arteriography (CAG) in detecting coronary artery stenosis suitable for coronary angioplasty in heart transplant recipients. METHODS: Within a 2-week interval during a follow-up period of 5.6 (95% confidence limits 2.1 to 12) years, 255 serial CAGs and myocardial perfusion scintigraphies were performed in 67 patients. Arteriography and scintigraphy were performed once yearly after heart transplantation. We retrospectively analyzed the data. RESULTS: Myocardial scintigraphy showed pathologic reversible defects in 9 out of 67 patients. Four of these patients had significant (>50% and also >70%) focal segmental stenosis in the middle and proximal parts of the coronary arteries (Type A lesions), 1 had diffuse and circumferential narrowing in the distal parts (Type B lesions), whereas CAG showed no lesions in the remaining 4 patients. The patients with significant Type A lesions were revascularized with percutaneous coronary angioplasty. Coronary arteriography showed that 1 patient had extensive Type A and Type B lesions, whereas myocardial perfusion scans detected no. The predictive value of a negative (normal) SPECT was 98% (95% confidence limits 94% to 100%) for the detection of lesions suited for revascularization. CONCLUSIONS: Annual myocardial SPECT seems well suited to screen for significant coronary artery stenosis. A SPECT study without reversible defects virtually excludes lesions suitable for coronary artery revascularization.

Emergency coronary artery bypass surgery after failed percutaneous transluminal coronary angioplasty.

Coronary complications caused by percutaneous transluminal coronary angioplasty (PTCA) may necessitate emergency coronary artery bypass grafting (CABG). In 1994-1998, 132 patients (1.5% of the patients registered in the Danish PTCA registry) underwent CABG within 24 h because of angioplasty complications. We reviewed the files of 86 patients who had emergency operations within 6 h and found that 35% suffered from 1-vessel disease. Fifty-eight percent were taken directly to the operating room from the cardiovascular laboratory, and 13% were given preoperative cardiovascular resuscitation. The vessels most frequently injured were the right coronary artery and the left anterior descending branch (LAD). The patients received a mean of 2.4 coronary bypasses each. Forty-three percent of the patients with lesions of the left main coronary artery and/or the LAD received a vein graft to the LAD. A perioperative Q-wave myocardial infarction developed in 51% of the patients. The in-hospital mortality rate was 12%. These results are inferior to those obtained after elective surgery. Local cardiothoracic backup is vital when PTCA is performed in an unselected patient group.

Calf blood flow during prolonged tilt in idiopathic dilated cardiomyopathy and after cardiac transplantation.

In severe congestive heart failure (CHF), abnormal reflex control of calf blood flow during brief head-up tilt that appears to normalize after transplantation (HTX) may be present during prolonged observation also. Therefore, we studied the effect of prolonged (30 min) 50 degrees head-up tilt on calf skeletal muscle blood flow measured by the local (133)Xe washout method in CHF and after HTX and in patients with the presence vs. absence of native right atrium (+PNA and -PNA, respectively). During brief head-up tilt, skeletal muscle blood flow increased 13 +/- 42% in 9 severe CHF patients in contrast to a -28 +/- 22% decrease (P < 0.01) in 11 control subjects, -24 +/- 30% decrease in 15 moderate CHF patients (P < 0.05), -25 +/- 14% decrease in 12 patients with recent HTX (P < 0.01), and -21 +/- 24% decrease in 8 patients with distant HTX (P = 0.06). However, during sustained tilt, blood flow declined to similar levels of that in the other groups in severe CHF. HTX -PNA vs. +PNA showed blunted skeletal muscle vasomotor control (P < 0.05) and a higher systolic blood pressure (139 +/- 14 vs. 125 +/- 15 mmHg, P < 0.05) and heart rate (92 +/- 10 vs. 83 +/- 8 beats/min, P < 0.05). Thus paradox vasodilatation of calf skeletal muscle in severe CHF is present only during brief but not prolonged tilt. This may be one explanation of the rare presence of orthostatic intolerance in CHF and implies only a minor possible role for the abnormality in edema pathogenesis. Removal of all right atrium in HTX has an important hemodynamic impact that may possibly affect later clinical outcome.

Effects of passive tilting on capillary filtration in the lower leg in idiopathic dilated cardiomyopathy and after heart transplantation for the same condition.

Abnormal reflex control of the peripheral microvasculature during orthostasis in congestive heart failure (CHF) and after heart transplantation (HT) may cause failure of microvascular homeostasis and peripheral edema. We explored the effect of passive head-up tilt on lower leg capillary filtration measured by strain-gauge plethysmography in 24 patients with CHF, in 20 patients after HT (12 patients with preserved native right atrium, 8 patients without native right atrium), and in 18 controls. We hypothesized that an impaired peripheral microvascular reflex during orthostasis in CHF and HT might allow increased arterial hydrostatic pressure to increase pressure at the capillary level. To identify an impact of changes in arterial hydrostatic pressure, capillary fluid filtration was expressed per mm Hg arterial hydrostatic pressure (capillary filtration coefficient(arterial pressure) [CFC(AP)]) and was measured (1) during elevated venous pressure alone (50 mm Hg venous stasis in supine position), and (2) during elevated hydrostatic pressure at both the venous and arterial side of the vascular tree (head-up tilt with a vertical distance from the right atrium to the strain-gauge of 68 cm of water [50 mmHg]). Elevated venous pressure alone resulted in the highest CFC(AP) in controls (0.79+/-0.28 ml/min x 100 ml mm Hg x 10(-3)+/-SD) versus those with CHF (0.44+/-0.23, p <0.0001) and those after HT (0.54+/-0.22, p <0.01). However, during head-up tilt, CFC(AP) was similar in all 3 groups, because CFC(AP) decreased in controls (to 0.49+/-0.22, p <0.0001), in contrast to unchanged CFC(AP) in those with CHF (0.43+/-0.24) and in those with HT (0.50+/-0.21). HT patients with complete removal of the native right atrium had higher CFC(AP) (0.62+/-0.17) during head-up tilt than patients with preserved native right atrium (0.36+/-0.16, p <0.005). In conclusion, patients with CHF and those after HT have increased capillary filtration to a lesser degree than controls during elevated venous pressure alone. However, during orthostasis this apparent edema-protective mechanism vanishes, probably because of compromised microvascular reflex control. During daily upright activities, this may be one important factor in the edema pathogenesis. The phenomenon is particularly distinct in HT patients without preserved native right atrium.

Pulmonary function in chronic heart failure. Changes after heart transplantation.

To investigate the impact of chronic heart failure on pulmonary function in heart transplant recipients, pulmonary function was evaluated in 41 consecutive patients (mean age 43 years, range 15-57 years) before and 6 months after successful heart transplantation. The pulmonary function tests included measurements of forced vital capacity [FVC], forced expiratory volume in 1.s [FEV1], FEV1/FVC ratio, total lung capacity [TLC], and diffusion capacity for carbon monoxide [TLCO] and KCO [TLCO per l alveolar volume]. Compared to pretransplant values, spirometry after transplantation revealed modest improvements in FVC (from 77 +/- 16 to 88 +/- 21% of predicted [%pred]; p < 0.001) and FEV1 (from 75 +/- 16 to 85 +/- 22%pred; p < 0.001), whereas the FEV1/FVC ratio was unchanged (81% +/- 11 and 80% +/- 10; p = NS). A slight but statistically significant increase in TLC (from 78 +/- 15 to 86 +/- 18%pred, p < 0.001) was also observed. Prior to transplantation the mean TLCO was 76 +/- 17%pred; 7 of the patients had a TLCO below 60%pred (mean 51% pred). In 33 of the 41 patients a reduction in TLCO was observed after transplantation; for all 41 patients the mean fall in TLCO was 14% of the predicted value (SD 12%pred) (p < 0.0001). Likewise, a significant reduction in KCO was noted (p < 0.0001). Multiple regression analysis revealed that high pretransplant TLCO %pred (p = 0.02) and FVC %pred (p = 0.04) were associated with a less favorable outcome concerning posttransplant TLCO %pred. Although normalization of FEV1, FVC and TLC can be anticipated after correction of severe chronic left ventricular failure by heart transplantation, the pronounced concomitant decline in diffusion capacity observed in this study may be explained by underlying pulmonary disease caused by factors other than long-standing heart failure. Our findings support the notion that pulmonary function abnormalities attributable to chronic heart failure should not preclude consideration for heart transplantation.

CABG shortly after AMI treated with thrombolysis: an analysis of the surgical group and a comparison with PTCA in the DANAMI study. Danish multicenter randomized study of invasive versus conservative treatment in patients with inducible ischemia after thrombolysis in acute myocardial infarction.

OBJECTIVE: To present surgical results of the DANAMI study comparing conservative and invasive treatment of postinfarction myocardial ischaemia and to compare these with percutaneous transluminal angioplasty (PTCA) which was the alternative invasive treatment in that study. METHODS: A group of 413 patients with verified acute myocardial infarction treated with thrombolysis within 12 h of the onset of symptoms, who demonstrated postinfarction myocardial ischaemia were treated with coronary artery bypass grafting (CABG) or PTCA. Patients with left main lesions, three-vessel disease, two-vessel disease with more than three stenoses and patients with occlusions of a non-infarct related vessel had primary CABG. Patients with 1- and 2-vessel disease with not more than a total of three stenoses had PTCA. In case of failed PTCA patients had secondary CABG. The median distance from AMI to CABG was 45 days. PTCA was performed at a mean of 39 days after the infarction. RESULTS: A total of 147 patients had CABG and 266 had PTCA. The operative mortality for CABG was 1.4%. No PTCA patients died in relation to the procedure, 0.8% developed acute myocardial infarction as a consequence of the procedure, 1.5% had acute CABG and 3.5% elective CABG due to failed PTCA. In spite of more severe coronary artery disease among the CABG patients there was no difference in survival at 2.4 years. The CABG group had significantly fewer episodes of unstable angina, 10.2% versus 25.6% (P = 0.0002). No CABG patients had re-do revascularisation at 2.4 years follow-up versus 15.4% of the PTCA patients. At 3 years 80% of the CABG patients were free of angina compared to the 61% of the PTCA group (P < 0.0001). CONCLUSION: Low morbidity and mortality justifies the deferred elective revascularisation in patients with postinfarction myocardial ischaemia even in patients with silent ischaemia. There is no difference in survival at 2.4 years between CABG and PTCA but CABG offers more lasting results concerning incidence of stable and unstable angina than PTCA, which, however, is a valuable alternative in patients with less severe coronary artery disease.

Danish multicenter randomized study of invasive versus conservative treatment in patients with inducible ischemia after thrombolysis in acute myocardial infarction (DANAMI). DANish trial in Acute Myocardial Infarction.

BACKGROUND: The aim of the DANish trial in Acute Myocardial Infarction (DANAMI) study was to compare an invasive strategy of percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG) with a conservative strategy in patients with inducible myocardial ischemia who received thrombolytic treatment for a first acute myocardial infarction (AMI). METHODS AND RESULTS: Of the 503 patients randomized to an invasive strategy, PTCA was performed in 266 (52.9%) and CABG in 147 (29.2%) from 2 to 10 weeks after the AMI. Of the 505 patients in the conservative treatment group, only 8 (1.6%) had been revascularized 2 months after the AMI. The patients were followed up from 1 to 4.5 years. The primary end points were mortality, reinfarction, and admission with unstable angina. At 2.4 years' follow-up (median), mortality was 3.6% in the invasive treatment group and 4.4% in the conservative treatment group (not significant). Invasive treatment was associated with a lower incidence of AMI (5.6% versus 10.5%; P=.0038) and a lower incidence of admission for unstable angina (17.9% versus 29.5%; P<.00001). The percentages of patients with a primary end point were 15.4% and 29.5% at 1 year, 23.5% and 36.6% at 2 years, and 31.7% versus 44.0% at 4 years (P=<.00001) in the invasive and conservative treatment groups, respectively. At 12 months, stable angina pectoris was present in 21% of patients in the invasive treatment group and 43% in the conservative treatment group. CONCLUSIONS: Invasive treatment in post-AMI patients with inducible ischemia results in a reduction in the incidence of reinfarction, fewer admissions due to unstable angina, and lower prevalence of stable angina. We conclude that patients with inducible ischemia before discharge who have received treatment with thrombolytic drugs for their first AMI should be referred to coronary arteriography and revascularized accordingly.

[Clinical results after en block double lung transplantation with direct bronchial revascularization. The first three and a half years' experience in Denmark]. / Kliniske resultater efter en bloc dobbeltlungetransplantation med direkte bronkial revaskularisering. De første tre et halvt års erfaring i Danmark.

En-bloc double lung transplantation with tracheal anastomosis and direct revascularization of the bronchial arteries to the left internal mammary artery has been carried out in Denmark since June 1992. Forty-seven patients (32 with alfa-1 antitrypsin deficiency, 11 with chronic obstructive pulmonary disease, two with cystic fibrosis and two with primary pulmonary hypertension), 25 men and 22 women, average age 39 years (17-64 years), have received their first double-lung transplant with bronchial artery revascularization. Arteriography of the internal mammary artery and bronchial arteries was performed in 42 (89%) of the patients from 1-150 days after the operation. Successful bronchial artery revascularization was demonstrated arteriographically in 40 patients, in two patients the arteriography failed to show bronchial artery revascularization. Arteriography was not performed in five patients due to early complications and death. Bronchoscopy showed rapid, uncomplicated airway healing in 42 patients. Mucosal necrosis under the tracheal anastomosis was found in three patients, and severe obstructive endobronchial growth of the fungus Aspergillus fumigatus was diagnosed in the last two patients. The one- and two-year survival is 83% (Kaplan-Meier). Eleven patients are dead, five due to pulmonary causes and six due to extra-pulmonary causes. Pulmonary function became normal in nearly all surviving patients between three to six months after the transplantation. In conclusion, en-bloc double-lung transplantation with bronchial artery vascularization has shown good short-term results, and the one- and two-year survival gives hope that a successful bronchial artery revascularization will improve the long-term survival following lung transplantation.

Surgical and arteriographic results of bronchial artery revascularization in lung and heart lung transplantation.

BACKGROUND: On the basis of our experience with bronchial artery revascularization (BAR) in lung transplantation since its introduction in Copenhagen in 1992, a description of the surgical anatomy of the bronchial arteries and the results of attempted BAR in these patients will be presented. METHODS: Since June 1992, BAR was performed in 50 en bloc double lung, six single lung, and nine heart-lung transplantations. The location, number, type, and size of each bronchial artery identified and revascularized were recorded. Our choice of conduit for BAR was the internal mammary artery. Routine internal mammary-bronchial arteriography was performed early after the transplantation to evaluate the result of BAR. All arteriograms were carefully studied together with the surgical records. The arteriographic results after attempted BAR were classified as complete, incomplete (bilateral, hemilateral, or poor), or failed. The surgical and arteriographic anatomy of the bronchial arteries has been described, and nomenclature for the as yet unnamed bronchial arteries has been developed. RESULTS: During surgery 128 bronchial arteries were identified in the descending aorta of the 64 donor lung blocs. Internal mammary-bronchial arteriography was performed in 53 patients. BAR was complete in 32, incomplete in 18, and failed in 3. The number of bronchial arteries identified and revascularized in each case increased with experience. The central and intrapulmonary bronchial artery anatomy was described, and different patterns have been identified. CONCLUSIONS: Bronchial artery identification is reliable, but a learning process is involved. BAR is possible with a high success rate. Complete BAR is an obtainable goal in most cases.

Direct bronchial artery revascularization and en bloc double lung transplantation--surgical techniques and early outcome.

BACKGROUND: Lung transplantation including direct bronchial artery revascularization (BAR) has produced promising early results in small clinical series. METHODS: In Copenhagen primary en bloc double lung transplantation with BAR, with the left mammary artery used as conduit, has been performed in 47 patients from 1992 to the end of 1995. After introduction of the bloc into the recipient, the mammary-to-bronchial artery anastomosis is performed as the first anastomosis, allowing perfect exposure and early reperfusion. Internal mammary-bronchial artery arteriography has been performed routinely after operation. RESULTS: Bronchoscopic examination performed in all patients documented normal airway healing in 42, disturbed in two, and complicated in three. Arteriography performed in 42 patients demonstrated complete BAR in 25, incomplete in 15, and failed BAR in 2. Failed BAR was associated with complicated airway healing. The 1- and 2-year survival rate (Kaplan-Meyer) is 83%. Eleven patients have died, only one within 30 days. The total incidence of bronchiolitis obliterans syndrome at 3 years (with Kaplan-Meier technique) is 33%. Successful BAR has also been performed with an adjusted technique in a limited number of heart-lung and single lung transplantations. Our total experience of BAR in any type of lung transplantation includes 65 patients with an arteriographic BAR success rate of 94% (50 of 53 examined patients). CONCLUSIONS: Experience has improved the surgical technique and has made BAR reliable and safe, be it double lung, single lung, or heart-lung transplantation. Early results are good, but only follow-up will show if long-term results after lung transplantation will be improved by BAR. Already today, en bloc double lung transplantation with BAR is a viable alternative to sequential bilateral lung transplantation.

[Coronary bypass surgery at the Rigshospitalet 1993-1995. Results after 1.000 consecutive operations]. / Koronar bypass-kirurgi på Rigshospitalet 1993-1995. Resultater efter 1.000 konsekutive operationer.

During 1993-95 1000 consecutive patients were admitted for coronary bypass surgery. The total 30-day mortality of 1.9% was 0.9% for elective cases, 0.8% for reoperations and 0.2% for urgent cases. Perioperative myocardial infarction occurred in 44 patients of whom 25% had infarction at the start of the operation. Respiratory insufficiency occurred in 1.4% of the patients, 3.6% developed renal insufficiency and 1.8% had neurological defects postoperatively. Reoperation for bleeding occurred in 6%, and 0.2% developed sternal or mediastinal infection. This study demonstrates that the results of coronary bypass surgery at Rigshospitalet, Copenhagen are fully comparable to similar results in our neighbouring countries. The results can probably be further improved by more intensive treatment of perioperative ischaemia, especially in reoperations and urgent cases.

Effect of nitroglycerin in patients with increased pulmonary vascular resistance undergoing cardiac transplantation.

Acute right ventricular failure due to persistent pulmonary hypertension is a risk factor for premature death after cardiac transplantation. The purpose of this study was to follow changes in pulmonary haemodynamics in patients with pulmonary hypertension undergoing heart transplantation, and to examine whether postoperative changes can be predicted from a preoperative nitroglycerin (NTG) challenge. Seventeen consecutive patients with NYHA class IV heart failure and pulmonary hypertension (pulmonal vascular resistance (PVR) > 2.5 Wood units) underwent an NTG infusion before cardiac transplantation and were followed up using measurements of pulmonary haemodynamics before, early (24 h) and late (6 months) after cardiac transplantation. The effect of NTG was measured preoperatively and compared with posttransplantation values. Postoperative (24 h) PVR was reduced in all patients when compared with preoperative findings (PVR from 4.1 +/- 0.2 to 1.9 +/- 0.2 Wood units, Mean +/- SEM, p < 0.05). Mean pulmonary artery pressure (mPAP) was lowered in 16 of out 17 patients (41 +/- 2 to 26 +/- 1 mmHg, p < 0.05). None of the parameters were significantly changed during the subsequent 6 months. Postoperative PVR and mPAP were accurately estimated by preoperative NTG infusion (NTG vs 24 h posttranspl: PVR 2.2 +/- 0.2 vs 1.9 +/- 0.2 Wood units, p > 0.05; mPAP 30 +/- 2 vs 26 +/- 1 mmHg, p > 0.05). Heart transplantation candidates with pulmonary hypertension responsive to NTG can be expected to obtain a postoperative immediate fall in pulmonary pressures and PVR. The magnitude of this circulatory improvement can be predicted from a preoperative NTG infusion and is not different from values measured 6 months after transplantation.

Significance and management of early graft failure after coronary artery bypass grafting: feasibility and results of acute angiography and re-re-vascularization.

UNLABELLED: Perioperative ischaemia and infarction after CABG are associated with increased morbidity and mortality. OBJECTIVE: To study causes of perioperative ischaemia and infarction by acute re-angiography and to treat incomplete re-vascularization caused by graft failure or any other cause. METHODS: Between 1990 and 1995, 2003 patients underwent an isolated CABG operation. Myocardial ischaemia was suspected if one or more of the following criteria were present: New changes in the ST-segment in the ECG; a CKMB value greater than 80 U/L; new Q-waves in the ECG; recurrent episodes of, or sustained ventricular tachyarrhythmia; ventricular fibrillation; haemodynamic deterioration and left ventricular failure. Acute coronary angiography was performed in stable patients, while haemodynamically severely compromised patients were rushed to the operating room. RESULTS: A total of 71 (3.5%) patients of all CABGs with suspected graft failure were identified and included in the study. Patients were grouped according to whether they had an acute re-angiography (n = 59; group 1) or an immediate re-operation (n = 12; group 2) performed. In group 1, the acute re-angiography demonstrated graft failure/incomplete re-vascularization in 43 patients (73%). The angiographic findings were: Occluded vein graft(s) in 19 (32%); poor distal run-off to the grafted coronary artery in ten (17%); internal mammary artery stenosis in four (7%); internal mammary artery occlusion in three (5%); vein graft stenoses in three (5%); left mammary artery subclavian artery steal in two (3%); and the wrong coronary artery grafted in one (2%). Based on the angiography findings, 27 patients were re-operated and re-grafted. At the time of re-operation, 18 patients (67%) had evolving infarction documented by ECG or CKMB. Two patients (3%) experienced stroke in immediate relation to the re-angiography. The 30-day mortality was three (7%). In group 2, graft occlusions were found in 11 patients (92%). The 30-day mortality was six (50%). CONCLUSION: An acute re-angiography demonstrated graft failure or incomplete re-vascularization in the majority of patients with myocardial ischaemia early after CABG. Re-operation for re-re-vascularization was performed with low risk. Few patients with circulatory collapse could be saved by an immediate re-operation without preceding angiography.