Effects of exogenous surfactant on the non‐heart‐beating donor lung graft in experimental lung transplantation – a stereological study

The use of non‐heart‐beating donor (NHBD) lungs may help to overcome the shortage of lung grafts in clinical lung transplantation, but warm ischaemia and ischaemia/reperfusion injury (I/R injury) resulting in primary graft dysfunction represent a considerable threat. Thus, better strategies for optimized preservation of lung grafts are urgently needed. Surfactant dysfunction has been shown to contribute to I/R injury, and surfactant replacement therapy is effective in enhancing lung function and structural integrity in related rat models. In the present study we hypothesize that surfactant replacement therapy reduces oedema formation in a pig model of NHBD lung transplantation. Oedema formation was quantified with (SF) and without (non‐SF) surfactant replacement therapy in interstitial and alveolar compartments by means of design‐based stereology in NHBD lungs 7 h after cardiac arrest, reperfusion and transplantation. A sham‐operated group served as control. In both NHBD groups, nearly all animals died within the first hours after transplantation due to right heart failure. Both SF and non‐SF developed an interstitial oedema of similar degree, as shown by an increase in septal wall volume and arithmetic mean thickness as well as an increase in the volume of peribron‐chovascular connective tissue. Regarding intra‐alveolar oedema, no statistically significant difference could be found between SF and non‐SF. In conclusion, surfactant replacement therapy cannot prevent poor outcome after prolonged warm ischaemia of 7 h in this model. While the beneficial effects of surfactant replacement therapy have been observed in several experimental and clinical studies related to heart‐beating donor lungs and cold ischaemia, it is unlikely that surfactant replacement therapy will overcome the shortage of organs in the context of prolonged warm ischaemia, for example, 7 h. Moreover, our data demonstrate that right heart function and dysfunctions of the pulmonary vascular bed are limiting factors that need to be addressed in NHBD.     

Heart transplantation and consecutive mitral valve replacement

A 48-year-old man was diagnosed with progressive mitral insufficiency due to fibrosis of papillary muscles and chordae tendineae, necessitating mitral valve replacement (MVR) 8 months after cardiac transplantation. Donor echocardiography and inspection of the heart at procurement were inconspicuous. The patient is alive, free from valve-related complications and functionally improved six years after MVR. The limited yet successful experiences with left-sided valve repair or replacement in the transplanted heart are reviewed.     

Intermittent antegrade warm myocardial protection compared to intermittent cold blood cardioplegia in elective coronary surgery--do we have to change?

OBJECTIVE: Intermittent antegrade warm blood cardioplegia (IAWBC) is a simple and cost-effective method of myocardial preservation. However, there are only few prospective trials comparing this type of cardioplegia to established cardioplegic strategies in elective on-pump coronary surgery with respect to myocardial protection and outcome. METHODS: In a prospective, randomized trial IAWBC (33 degrees C) (n=100) was compared to intermittent antegrade cold (4 degrees C) blood cardioplegia (n=100), regarding clinical outcome and myocardial protection using cardiac troponin-I (cTNI) and creatine kinase MB isoenzyme (CK-MB) measurements to assess ischemia. RESULTS: Preoperative parameters were comparable in both groups. Results demonstrated no differences in-between the groups regarding mortality (2.0% both), incidence of perioperative myocardial infarction (2 versus 3%), need for intra-aortic balloon pump (3 versus 4%), length of ICU stay (2.0+/-2.5 versus 2.1+/-3.0 days) and incidence of postoperative atrial fibrillation (41 versus 34%). However, the necessity of defibrillation after cardiac arrest (18 versus 43%, P<0.001) was significantly less frequent and of lower intensity (3.4+/-10.8 versus 10.8+/-20.6 J, P<0.001) in the IAWBC-group. Postoperatively the ischemia markers were significantly lower in the IAWBC-group, cTNI within the first 72 h (from P<0.001 to P=0.013) and even CK-MB within the first 24 h (from P=0.004 to P<0.011). CONCLUSION: IAWBC is a safe and simple method in elective on-pump coronary artery bypass surgery. Significantly lower ischemic markers suggest an improved myocardial protection compared to cold blood cardioplegia in these patients.     

Correlation between serial measurements of N-terminal pro brain natriuretic peptide and ambulatory cardiac filling pressures in outpatients with chronic heart failure

BACKGROUND: Serial measurements of N-terminal pro brain natriuretic peptide (NT-proBNP) have been suggested for the management of outpatients with chronic heart failure (CHF). The relationship between NT-proBNP plasma levels and central haemodynamic parameters in this setting is not known. METHODS: In 19 outpatients with CHF, NT-proBNP was related to central haemodynamic information, continuously measured with an implanted haemodynamic monitor (IHM) during 24 h of daily living activities ("24 h") and during supine rest ("rest"). In 13 patients, three to seven serial measurements were obtained with a mean time interval of 39 days (range 19-113). RESULTS: At the first visit (n=19), NT-proBNP plasma levels were dispersed over a wide range of filling pressures and not correlated with the 24 h median of the right ventricular systolic pressure (RVSP) and the estimated pulmonary artery pressure (ePAD). However, in the individual patient, serial measurements yielded significant positive correlations between NT-proBNP and RVSP (p=0.006) and ePAD (p=0.001). During "24 h" compared with "rest", the median RVSP and ePAD were elevated by 20+/-16% and 32+/-18%, respectively, and corresponded better with NT-proBNP (p<0.05). CONCLUSION: In outpatients with CHF, single measurements of NT-proBNP are not correlated with cardiac filling pressures. However, serial measurements of NT-proBNP in each individual patient show a significant positive correlation with central haemodynamic parameters and reflect changes in the haemodynamic state over time.     

Kinetic of procalcitonin in the early postoperative course following heart transplantation

Abstract   Background: It was the aim of the study to determine the kinetics of procalcitonin (PCT) levels following heart transplantation (HTx) and to investigate the prognostic suitability of postoperative changes in PCT levels for patients' outcome. Methods: 52 adult heart transplant recipients were divided into two groups according to their in-hospital postoperative outcome retrospectively. Group A (eventful ± nonsurvivors) of 24 patients (21 males, three females, mean age 54.5 ± 10.1 years) was compared with Group B (uneventful) of 28 patients (22 males, six females, mean age 53.6 ± 8.1 years). Results: Serum PCT levels were measured before and daily after operation until day seven. Demographic data, operative data, and clinical endpoints (mortality, infection, severe complication) were analyzed. Mean PCT levels immediately before HTx were <0.3 ng/mL in both groups, respectively. PCT increased with maximum concentrations on the second post-operative day (Group A: 54.6 ± 44.3 ng/mL; Group B: 9.1 ± 9.3 ng/mL). After day two the levels decreased to 7.8 ± 8.8 ng/mL in Group A and 0.6 ± 0.8 ng/mL in Group B on day seven. Postoperative PCT was increased in nonsurvivors compared to survivors in Group A (81.6 ± 58.7 ng/mL vs 44.7 ± 19.8 ng/ml; p < 0.05). Conclusions: PCT levels have been consistently low (<10 ng/mL) in patients with an uneventful course, but more frequently increased in patients with postoperative complications and even associated with an increased mortality early postoperatively when values exceed 80 ng/mL. As a clinical consequence, PCT levels in the first few days following cardiac transplantation can help to identify patients at risk, when concentrations exceed the "normal" posttransplant range.     

Excellent early and late outcomes of aortic valve replacement in people aged 80 and older

OBJECTIVES: To investigate early and late outcome of aortic valve replacement (AVR) in a large cohort of patients aged 80 and older.
DESIGN: Retrospective study of consecutive patients undergoing AVR using a computerized database based on the New York State Department of Health registry. Data collection was performed prospectively.
SETTING: University hospital (single institution).
PARTICIPANTS: One thousand three hundred eight patients undergoing AVR (231 (17.6%) aged ≥80, 1,077 (82.4%) <80).
MEASUREMENTS: Patient characteristics, hospital mortality, morbidity, length of stay and long-term survival were analyzed.
RESULTS: Subjects aged 80 and older were more likely to be female, had a lower body mass index, and presented significantly more often with comorbidities such as heart failure, renal failure, and extensive aortic calcification. Crude hospital mortality was 5.2% (n=12) in subjects age 80 and older, compared with 4.5% (n=48) in those younger than 80 ( P =.37). Respiratory failure occurred more frequently in those aged 80 and older. In multivariate logistic regression analysis, age of 80 and older was not a predictor of hospital mortality. The median length of stay was significantly higher in those aged 80 and older than in those younger than 80 (10 days vs 7 days, P =.01). Five-year survival was 64±5% in those aged 80 and older, which was similar to that of the age- and sex-matched general U.S. population.
CONCLUSION: Excellent results after AVR can be expected in patients aged 80 and older, with minimal increase in postoperative mortality and acceptable postoperative morbidity. Respiratory failure is the main postoperative complication in patients aged 80 and older. Recent advances in operative techniques and perioperative management have contributed to better surgical outcomes in these patients than found in historical reports.