Influence of temperature management on neurocognitive function in biological aortic valve replacement. A prospective randomized trial.

AIM: Aim of this study was to elucidate if postoperative neurocognitive function after biological aortic valve replacement (AVR) can be influenced by temperature management during cardiopulmonary bypass (CPB). METHODS: In this prospective randomized study, we measured the effect of mild hypothermic (32 °C, N.=30) vs. normothermic (37 °C, N.=30) CPB on neurocognitive function. All patients underwent elective isolated biological AVR (mean age 67 ± 8 years, mean additional EuroSCORE 5.6 ± 2.4). Neurocognitive function was objectively measured by means of objective P300 auditory-evoked potentials before surgery, one week and four months after surgery. Clinical data and outcome were monitored. RESULTS: P300 evoked potentials were comparable between patients operated with mild hypothermic (370 ± 30 ms) and normothermic CPB (373 ± 32 ms) before surgery (P=0.85). P300 peak latencies were prolonged (=impaired) in patients operated with normothermic (402 ± 29, P<0.0001) as well as with mild hypothermic CPB (405 ± 30 ms, P<0.0001) one week after surgery. Even four months after surgery, still impairment of P300 peak latencies could be documented in either patients operated with normothermic (394 ± 28 ms) and mild hypothermic CPB (400 ± 33 ms,) in repeated measures analysis of variance (P=0.042). Group comparison revealed no difference between patients operated with normothermic and mild hypothermic CPB at one week (P=0.54) and four months (P=0.67) after surgery. Clinical data as well as postoperative adverse events were comparable between the two groups. CONCLUSION: Normothermic temperature management during CPB is non-inferior to hypothermic in means of neuroprotection. Since patients after biological aortic valve replacement show a subclinical but measurable cognitive deficit up to four months after surgery, other factors have to be addressed to add further benefit to the extremely good results of open biological AVR.

Gender-related differences in patients undergoing mechanical aortic valve replacement with the CarboMedics valve.

AIM: The aim of this paper was to evaluate gender-related differences in patients undergoing mechanical aortic valve replacement with the CarboMedics valve. METHODS: During a 20 year period, 629 patients (median age 60 years) underwent mechanical aortic valve replacement with the CarboMedics valve. Of these, 215 patients were female (34%). The median follow-up for the entire cohort was 10.2 ± 6.2 years. RESULTS: In-hospital mortality for the entire cohort was 9% (male 7.3% vs. female 11.0%, P=0.005). Cox regression analysis revealed redo-surgery (HR=2.35, CI 1.35-4.08), LVEF<30% (HR=2.31, CI 1.36-3.93), age (HR=1.60, CI 1.27-2.02), as well as female gender (HR=2.07, CI 1.28-3.35) as independent predictors of survival. For male gender LVEF<30% (HR=2.47, CI 1.23-4.93) and age (HR=1.75, CI 1.25-2.43) were independent predictors of survival. For female gender, additional CABG (HR=2.15, CI 1.08-4.28), redo surgery (HR=3.64, CI 1.78-7.46) as well as age (HR=1.48, CI 1.06-2.06) were independent predictors of survival. CONCLUSION: Gender per se is an independent risk factor of survival after mechanical aortic valve replacement. Severely impaired LVEF independently predicts survival in males whereas additional CABG and redo surgery do in females. Age affects survival in both sexes. These findings may serve as a basis for further improving gender related outcome.

Human heart-type fatty-acid-binding protein as a point-of-care test in the early diagnosis of acute myocardial infarction.

BACKGROUND: At very early stages of acute myocardial infarction (AMI), highly sensitive biomarkers are still lacking. AIM: To evaluate the utility of human heart-type fatty acid-binding protein (h-FABP) for early diagnosis of AMI. DESIGN: Prospective diagnostic study. METHODS: Consecutive patients presenting to the emergency department with chest pain or dyspnoea within 24 h of symptom onset were included. At presentation, the h-FABP test result was compared to the standard diagnostic work-up, including repeated ECG and troponin T measurements. Sensitivity analysis was performed for inconclusive tests. RESULTS: We enrolled 280 patients presenting to hospital with a median symptom onset of 3 h (IQR 2-6 h): 109 (39%) had AMI. At presentation, h-FABP had a sensitivity of 69% (95%CI 59-77) and specificity of 74% (95%CI 66-80); 45 tests were false-positive and 34 were false-negative. Omitting inconclusive tests increased sensitivity and specificity only slightly. AMI was identified significantly earlier by h-FABP than by troponin T (24 vs. 8 patients, p=0.005). DISCUSSION: Although h-FABP can help to detect myocardial damage at an early stage in patients with chest pain or dyspnoea, it appears unsuitable as a stand-alone test for ruling out AMI.

Compromising bradycardia: management in the emergency department.

AIM OF THE STUDY: Bradycardia may represent a serious emergency. The need for temporary and permanent pacing is unknown. METHODS: We analysed a registry for the incidence, symptoms, presenting rhythm, underlying mechanism, management and outcome of patients presenting with compromising bradycardia to the emergency department of a university hospital retrospectively during a 10-year period. RESULTS: We identified 277 patients, 173 male (62%), median age 68 (IQR 58-78), median ventricular rate 33 min(-1) (IQR 30-40). The leading symptoms were syncope [94 (33%)], dizziness [61 (22%)], collapse [46 (17%)], angina [46 (17%)] and dyspnoea/heart failure [30 (11%)]. The initial ECG showed high grade AV block [134 (48%)], sinus bradycardia/AV block [46 (17%)], sinuatrial arrest [42 (15%)], bradycardic atrial fibrillation [39 (14%)] and pacemaker-failure [16 (6%)]. The underlying mechanisms were primary disturbance of cardiac automaticity and/or conduction [135 (49%)], adverse drug effect [58 (21%)], acute myocardial infarction [40 (14%)], pacemaker failure [16 (6%)], intoxication [16 (6%)] and electrolyte disorder [12 patients (4%)]. In 107 (39%) patients bed rest resolved the symptoms. Intravenous drugs to increase ventricular rate were given to 170 (61%) patients, 54 (20%) required additional temporary transvenous/transcutaneous pacing. Two severely intoxicated patients could be stabilised only by cardiopulmonary bypass. A permanent pacemaker was implanted in 137 patients (50%). Mortality was 5% at 30 days. CONCLUSION: In our cohort, about 20% of the patients presenting with compromising bradycardia required temporary emergency pacing for initial stabilisation, in 50% permanent pacing had to be established.

Proton pump inhibition prevents gastrointestinal bleeding in ultramarathon runners: a randomised, double blinded, placebo controlled study.

BACKGROUND: Ultra-endurance running is emerging as a popular sport in Western industrialised countries. Gastrointestinal bleeding has been reported to be an adverse effect in these runners. OBJECTIVE: To see if the oral administration of a proton pump inhibitor would reduce the incidence of gastrointestinal bleeding in an ultramarathon. METHODS: In a randomised, double blinded, placebo controlled study, a prophylactic regimen of three days of an oral proton pump inhibitor (pantoprazole 20 mg) was tested in healthy athletes participating in the Spartathlon ultramarathon. The incidence of gastrointestinal bleeding was assessed by a stool guaiac test. RESULTS: Results were obtained for 70 healthy volunteers. The data for 20 of 35 runners in the intervention group and 17 of 35 runners in the placebo group were entered into the final analysis. At the end of the ultramarathon, two subjects in the intervention group and 12 in the placebo group had positive stool guaiac tests (risk difference 0.86; 95% confidence interval 0.45 to 0.96; p = 0.001). CONCLUSION: A short prophylactic regimen of oral proton pump inhibition can successfully decrease the incidence of gastrointestinal bleeding in participants in an ultramarathon.

The role of Chlamydia pneumoniae in human aortic disease-a hypothesis revisited.

BACKGROUND: The role of Chlamydia pneumoniae in the pathogenesis of aortic aneurysm is controversial. We investigated the presence of C. pneumoniae in tissue samples excised from patients and controls. METHODS: Aortic wall specimens were obtained from 17 patients with acute Stanford type A aortic dissection, 25 patients with thoracic aortic aneurysms (TAA) and 23 patients with abdominal aortic aneurysms (AAA). Eighty-three tissue samples of 73 control patients free of aortic disease were obtained either at surgery or autopsy. The presence of Chlamydia subspecies DNA (sequences specific for all known Chlamydiaceae) and DNA of C. pneumoniae, C. trachomatis and C. psittaci were assessed by a validated highly sensitive and specific real time polymerase chain reaction (PCR) analysis. Atherosclerotic risk factors were assessed in all patients. RESULTS: We failed to detect C. pneumoniae and C. psittaci-DNA in any of the 148 vessel specimens. C. trachomatis-DNA was detected in 1/65 patients and in none of 83 controls (P=0.43). Chlamydia subspecies DNA was found in samples of eight cases and in one control (P=0.01), however, no significant differences were found between the subgroups aortic dissection (P=0.09), TAA (P=0.99) and AAA (P=0.15) and respective controls. CONCLUSIONS: C. pneumoniae does not play a clinically relevant role in acute and chronic aortic disease. The impact of other organisms of the family Chlamydiaceae needs further evaluation.

Treatment of toxoplasmosis in pregnancy: concentrations of spiramycin and neospiramycin in maternal serum and amniotic fluid.

Toxoplasma infection during pregnancy is widely treated with oral spiramycin to reduce the risk of congenital toxoplasmosis in the infant. Failures of therapy have been observed, however. In this study, a sensitive high-performance liquid chromatography technique was used to measure concentrations of spiramycin and neospiramycin, one of the major metabolites of spiramycin, in maternal serum and amniotic fluid. Samples were obtained from 18 women who underwent amniocentesis for polymerase chain reaction (PCR) diagnosis of fetal infection 5-109 days following the prescription of spiramycin therapy (3 g/day). Concentrations of spiramycin and neospiramycin in both serum and amniotic fluid were highly variable, ranging from nondetectable values to 1 microg/ml. None of the concentrations measured were within the range reported to inhibit growth of the parasite in vitro. Consistent with previous reports, part of the observed variability in maternal and fetal drug concentrations could be explained by individual differences in several pharmacokinetic parameters: intestinal absorption, tissue distribution, cellular uptake, metabolism, transfer across the placenta, drug accumulation in fetal tissue, and maternal and fetal drug elimination. The heterogeneity of the data could also be related to differences in patient compliance with the medication prescribed. By addressing factors that could impair adequate treatment of toxoplasmosis during pregnancy, the data presented call for a larger-scale controlled study to determine individual and diurnal variations in maternal drug levels, patient compliance, and outcomes of the offspring. The activity of neospiramycin against Toxoplasma gondii should be assessed.

Acute type A aortic dissection: the prognostic impact of preoperative cardiac tamponade.

OBJECTIVE: Acute type A aortic dissection requires emergency surgery and is associated with considerable mortality. The aim of the study was to evaluate whether occurrence of preoperative cardiac tamponade with or without palpable pulses in these patients is associated with higher incidence of multiple organ failure (MOF) and in-hospital mortality. METHODS: A retrospective cohort study included 87 patients with acute type A aortic dissection, who were admitted via an emergency department between December 1991 and December 1999 for emergency surgery. Impending cardiac tamponade (with palpable pulses) and severe cardiac tamponade (without palpable pulses) were recorded and patients were followed for occurrence of MOF and/or in-hospital mortality. RESULTS: Impending cardiac tamponade with palpable pulses was diagnosed in 33 patients (38%), signs of severe cardiac tamponade without palpable pulses were found in seven patients (8%). MOF occurred in 41 patients (47%); 32 patients (37%) died during the present stay, all of them had MOF. Preoperative severe cardiac tamponade without palpable pulses was associated with a significantly increased risk for poor outcome (odds ratio (OR)=16.1, 70% confidence interval (CI) 4.8-71.7, P=0.04), particularly preoperative death (n=6 of 7). Impending cardiac tamponade with palpable pulses (OR=1.6, 70% CI 0.8-3.3, P=0.2) was not associated with the occurrence of MOF/death. Hemodynamic shock (OR=6.5, 70% CI 3.0-13.9, P=0.01) was also associated with poor outcome. CONCLUSION: Patients with acute type A aortic dissection and signs of preoperative cardiac tamponade without palpable pulses had a 16-fold increased risk for poor outcome, particularly preoperative death. In contrast, cardiac tamponade with palpable pulses was not associated with increased frequency of MOF/in-hospital mortality.