The impact of establishing a regional infective endocarditis (IE) network on pre-operative IE-related complications and on post-operative outcome

Background

Infective endocarditis (IE) requires a high degree of suspicion and advanced level of multidisciplinary management. In 2015, the European guidelines recommended the formation of an endocarditis-team (ET) for optimal treatment of IE. In 2011, we already established an ET within the hospital that was only consulted on demand for certain patients. Since 2015, ET has been increasingly involved in the management of almost all patients with IE. In addition, we established in 2015 a statewide endocarditis- (E) network for the referring hospitals.

Purpose

We investigated the effect of E-network on reducing referral latency and pre-operative IE-related complications. We also investigated the adherence to the ET management recommendations in our hospital and its impact on post-operative stroke and mortality.

Methods

We retrospectively analyzed data from patients operated for IE in our center between 01/2007 and 03/2018. We conducted univariate analysis using Chi-square or Fisher's exact test, Multivariate logistic regression models for in-hospital mortality and post-operative stroke, and Kaplan-Meier estimate of 5-years survival.

Results

Among 630 patients operated for IE in our center, 409 (65%) underwent surgery in the 1st era before 12/2014. S. aureus IE was more frequent in the second era (34% vs 25%, p<0.001). The median time from the onset of symptoms to referral in the 2nd era was halved compared to the first one [7 days (IQR 2–19) vs 15 days (IQR 6–35)]. Patients in the 2nd era were admitted with less IE-related complications, i.e. less preoperative stroke (14% vs 27%, p<0.001), less heart failure (45% vs 69%, p<0.001) less cardiac abscesses (24% vs 34%, p=0.018), less acute renal insufficiency requiring hemodialysis (8% vs 14%, p=0.026). The lack of ET management recommendations was an independent predictor for in-hospital mortality (adjusted OR: 2.13, 95% CI: 1.27–3.53, p=0.004) and post-operative stroke (adjusted OR: 2.23, 95% CI: 1.12–4.39, p=0.02), and was associated with worse 5-years survival (59% compared to 40%, log rank<0.001).

Conclusion

Endocarditis-network led to earlier referral of patients, which resulted in less IE-related complications on admission. Lack of ET management recommendations was an independent predictor for post-operative stroke, in-hospital mortality and was associated with worse 5-years survival.

Funding Acknowledgement

Type of funding sources: None. Figure 1Figure 2

Coronary computed tomography angiography for heart team decision-making in multivessel coronary artery disease

Aims

Coronary computed tomography angiography (CTA) has emerged as a non-invasive diagnostic method for patients with suspected coronary artery disease, but its usefulness in patients with complex coronary artery disease remains to be investigated. The present study sought to determine the agreement between separate heart teams on treatment decision-making based on either coronary CTA or conventional angiography.

Methods and results

Separate heart teams composed of an interventional cardiologist, a cardiac surgeon, and a radiologist were randomized to assess the coronary artery disease with either coronary CTA or conventional angiography in patients with de novo left main or three-vessel coronary artery disease. Each heart team, blinded for the other imaging modality, quantified the anatomical complexity using the SYNTAX score and integrated clinical information using the SYNTAX Score II to provide a treatment recommendations based on mortality prediction at 4 years: coronary artery bypass grafting (CABG), percutaneous coronary intervention (PCI), or equipoise between CABG and PCI. The primary endpoint was the agreement between heart teams on the revascularization strategy. The secondary endpoint was the impact of fractional flow reserve derived from coronary CTA (FFRCT) on treatment decision and procedural planning. Overall, 223 patients were included. A treatment recommendation of CABG was made in 28% of the cases with coronary CTA and in 26% with conventional angiography. The agreement concerning treatment decision between coronary CTA and conventional angiography was high (Cohen's kappa 0.82, 95% confidence interval 0.74-0.91). The heart teams agreed on the coronary segments to be revascularized in 80% of the cases. FFRCT was available for 869/1108 lesions (196/223 patients). Fractional flow reserve derived from coronary CTA changed the treatment decision in 7% of the patients.

Conclusion

In patients with left main or three-vessel coronary artery disease, a heart team treatment decision-making based on coronary CTA showed high agreement with the decision derived from conventional coronary angiography suggesting the potential feasibility of a treatment decision-making and planning based solely on this non-invasive imaging modality and clinical information.

Trial registration number

NCT02813473.

Predictors of future arrhythmic events in patients with unexplained syncope

AIMS

The purpose of this study was to examine the usefulness of implantable loop recorders (ILRs) for symptom-rhythm correlation and to identify predictors of future arrhythmic events.

PATIENTS AND METHODS

In our dual-centre study, we analysed ILR data of 189 patients (mean age 67.4 ± 15.2 years, 114 male) with unexplained syncope (single syncope 21 patients, recurrent 168 patients, traumatic injury 43 patients). Patients had severe comorbidities such as hypertension (n = 127), coronary artery disease (n = 31), diabetes mellitus (n = 33) and chronic renal insufficiency (n = 18). The median ILR usage was 29 months (M), with a range between 1 and 46 M.

RESULTS

Forty-nine (26%) patients experienced syncope during the study, with a median of 8 M to first recurrence of syncope. In 43 patients, pacemaker implantation was performed because of sinus node disease (n = 29), high-degree AV-block (n = 6) or atrial fibrillation with slow ventricular rate (n = 8). In five patients, an ICD was implanted because of documented ventricular tachycardia (n = 4) or left ventricular ejection fraction <35% (n = 1). One patient received ablation of the cavotricuspid isthmus because of documented atrial flutter. Concerning the clinical course, in five patients explantation of the ILR was necessary due to pocket infection. Three patients died due to non-cardiac causes. Logistic regression analysis revealed that older patients had a significantly higher risk for future arrhythmic events (OR 1.3, p = .039).

CONCLUSIONS

ILR monitoring is effective in indicating causes of unexplained syncope by providing symptom-rhythm associations. Only age was a predictor of future arrhythmic events. The mortality in patients with unexplained syncope was very low.

[Renal manifestations of light chain associated diseases - epidemiology and prognosis]

BACKGROUND

An impaired renal function in light chain associated disorders may be caused by myeloma cast nephropathy (MCN) but also by AL-amyloidosis (AL-A) and monoclonal immundeposition disease (MIDD).

PATIENTS AND METHODS

In a monocentric, retrospective analysis, patients suffering from multiple myeloma (MM) (n = 392) requiring medical therapy, AL-A (n = 53) or MIDD (n = 12) diagnosed between 1996 and 2008 were evaluated for renal insufficiency. The different patient cohorts were compared in terms of their clinical course and outcome.

RESULTS

Renal insufficiency in MM-, AL-A- or MIDD-patients at the time of diagnosis was found in 45,5 % of the patients. MCN, AL-A and MIDD were found in 68, 25 and 6 %, respectively. Dialysis dependency was seen in 17 % of MCN, in 8 % of AL-A and in 50 % of MIDD patients. Signs of hypervolemia were the leading symptoms in MIDD/AL-A. The time between the occurence of first symptoms and diagnosis was as long as 52 weeks in patients with AL-A. Patients with renal involvement showed a reduced median survival of 17 compared with 77 months in patients with a normal renal function. Median survival was only 12 months in AL-A compared to 21 months in MCN. Stabilization of renal function after chemotherapy occurred only in MCN. Multivariate Cox regression analysis showed impaired renal function as independent risk factor (Hazard-Ratio 2,88 [2,06-4,0]. In terms of survival and kidney function, autologous stem cell transplantation (ASCT) was beneficial for patients with renal involvement.

CONCLUSION

Renal insufficiency is an independent risk factor in MM, AL-A and MIDD. Specific therapy, especially ASCT may improve prognosis in patients with renal insufficiency and could stabilize renal function in MCN-patients.

Expression of androgen-binding protein (ABP) in human cardiac myocytes

Cardiomyocytes are known to be androgen targets. Changing systemic steroid levels are thought to be linked to various cardiac ailments, including dilated cardiomyopathy (DCM). The mode of action of gonadal steroid hormones on the human heart is unknown to date. In the present study, we used high-resolution immunocytochemistry on semithin sections (1 microm thick), IN SITU hybridization, and mass spectrometry to investigate the expression of androgen-binding protein (ABP) in human myocardial biopsies taken from male patients with DCM. We observed distinct cytoplasmic ABP immunoreactivity in a fraction of the myocytes. IN SITU hybridization with synthetic oligonucleotide probes revealed specific hybridization signals in these cells. A portion of the ABP-positive cells contained immunostaining for androgen receptor. With SELDI TOF mass spectrometry of affinity purified tissue extracts of human myocardium, we confirmed the presence of a 50 kDa protein similar to ABP. Our observations provide evidence of an intrinsic expression of ABP in human heart. ABP may be secreted from myocytes in a paracrine manner perhaps to influence the bioavailabity of gonadal steroids in myocardium.

Doppelbilder und kardiogener Schock

Idiopathic giant cell myocarditis is a rare and frequently fatal inflammatory heart disease which leads to congestive heart failure or ventricular arrhythmias. It is often associated with other autoimmune disorders. We report a 39-year-old woman who first presented with diplopia and painful eye movements, the typical clinical picture of orbital myositis. Shortly afterwards, she developed rapidly progressive congestive heart failure due to giant cell myocarditis, which took a fatal course within some weeks. Autopsy confirmed both disorders. This case report underlines the importance of early and repeated monitoring of cardiac function, if orbital myositis is suspected, in order to consider cardiac transplantation, the only efficacious treatment of giant cell myocarditis, in time.

Damaged myocytes as detected by the colocalization of DNA fragmentation and tissue transglutaminase and their prognostic significance in enterovirus-associated dilated cardiomyopathy

BACKGROUND

Apoptotic cardiac myocytes have been described in chronic heart failure, but no data exist on the relationship between these 'damaged' myocytes and myocardial detection of enterovirus RNA often associated with dilated cardiomyopathy (DCM).

DESIGN

In patients with idiopathic DCM, endomyocardial biopsy samples were studied for enteroviral RNA by one step reverse transcription-polymerase chain reaction (PCR) and a subsequent hybridization of the PCR product using a Southern blot technique. The endomyocardial biopsies were further investigated for markers of cell damage and apoptosis: DNA fragmentation and expression of tissue-transglutaminase (TTG) in the myocytes using the in-situ endlabelling method or an anti-TTG-staining, respectively. To assess the prognostic significance of these two markers the correlation between the percentage of myocytes positive both for DNA fragmentation and TTG (the index of damaged myocytes) and the hemodynamic course of the patients during a mean follow-up period of 15.9 +/- 6.2 months was investigated prospectively by echocardiography.

RESULTS

In 14 (45%) of the 31 patients with idiopathic DCM, enteroviral RNA was found in the endomyocardial biopsy samples, while 17 patients (55%) were enterovirus-negative. In enterovirus-positive patients, the index of 'damaged' myocytes was significantly lower (10.7 +/- 4.9% vs. 19.2 +/- 8.8%, P = 0.002) and the left ventricular ejection fraction (LVEF) improved significantly (P = 0.00017 vs. P = 0.13) during long-term follow-up. In addition, a weak negative correlation was seen between the index of damaged myocytes and the changes in LVEF in all patients during long-term follow-up (r = - 0.48, P = 0.004).

CONCLUSION

Our results favour the view that enterovirus-positive patients with DCM have less damaged myocytes and a better haemodynamic course than enterovirus-negative patients.

Immunohistochemical properties of dipyrone-induced cytochromes P450 in rats

1. Rat hepatic cytochrome P450s induced by dipyrone were studied enzymatically, immunochemically and immunohistochemically. 2. Dipyrone administered to male Wistar rats increased pentoxyresorufin O-depentylation (PROD), ethoxyresorufin O-deethylation (EROD) and 7-ethoxycoumarin O-deethylation (ECOD) activities up to 44-, 1.9-, and 2.6-fold, respectively. Aryl hydrocarbon hydroxylase (AHH) activity was not affected. 3. Immunoinhibition with the monoclonal antibody (Mab) 2-66-3 (to CYP2B1/2) markedly decreased PROD and EROD activities, but not AHH activity. The Mab 1-7-1 (to CYP1A1/2) was without effect. 4. Histochemically, the Mab 2-66-3 gave a strong and uniform staining in livers from dipyrone-treated rats, whereas the Mab 1-7-1 gave a positive reaction in a narrow perivenous strip. 5. The induction pattern as well as inhibition by the Mabs convincingly demonstrate the predominant production of CYP2B1/2 in the induction spectrum of dipyrone. The increase in enzyme activities other than PROD may be due to the overlapping substrate specificity of CYP2B1/2 enzymes. The immunohistochemical analysis also indicated the participation of CYP1A1/2.

[An anticholinergic syndrome with hallucinatory psychosis after diphenhydramine poisoning]

HISTORY AND CLINICAL FINDINGS

A 27-year-old female student was hospitalized as an emergency because of gait and speech disorders which had developed over just a few hours. Conflicts with her partner and frequent alcohol abuse were reported. It was not possible to interview the patient herself. Consciousness was clouded by optical and acoustic hallucination. Body temperature was 38.1 degrees C: the skin was warm and dry, the tongue dry. Heart rate was 120/min, blood pressure 150/100 mm Hg. Neck and limb muscle tone was increased. Hallucinatory psychosis, encephalitis and alcohol withdrawal delirium were considered in the differential diagnosis.

TESTS

There was hypokalaemia, slightly increased serum creatinine and metabolic alkalosis. The alcohol level was 0.18%. The ECG was normal except for sinus tachycardia.

TREATMENT AND COURSE

In the meantime, two empty packets of 20 tablets each had been found in the patient's flat. They had contained Vivinox and Sediat (total of 1.5 g diphenhydramine), so that a central anticholinergic syndrome due to an overdose with this drug could be assumed. The diphenhydramine level was 2.8 micrograms/ml. After administration of altogether four times 2 mg physostigmine and 5 mg diazepam intravenously and normalization of electrolytes the symptoms regressed within 12 hours. The patient then admitted to having taken the drugs with suicidal intent. She was transferred to the psychiatric department because of the risk of further suicidal attempts.

Coronary vascular hyperpermeability and angiotensin II

Elevations in plasma angiotensin II (AngII) are associated with evidence of vascular hyperpermeability expressed as efflux of plasma macromolecules into the perivascular and interstitial space. This exudative response is followed by a series of fibrogenic events that lead to a perivascular fibrosis of involved vessels. Mediators of hyperpermeability and fibrogenesis are unknown. In dogs receiving intravenous AngII, hemodynamic factors (i.e., arterial hypertension or coronary venoconstriction) were discounted as being responsible for the rise in cardiac lymph-to-plasma protein ratio. Accordingly, we investigated the relationship between AngII-induced coronary hyperpermeability and the release of prostaglandin E2 (PGE2) and activation of the basement membrane degrading matrix metalloproteinase, gelatinase/type IV collagenase. In dogs, cardiac lymph was monitored over the course of a 90-minute intravenous infusion of either AngII (0.2 to 0.3 micrograms/kg/min; n = 8) or saline solution (n = 6). Lymph was examined at 30-minute intervals for the following: total protein (Lowry's method), albumin (sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE)), plasma fibronectin (SDS-PAGE and enzyme-linked immunosorbent assay); PGE2 (radioimmunoassay) and gelatinase/type IV collagenase (zymography). In comparison with baseline we found a consistent rise in lymph flow (p = 0.02), total protein (p = 0.02), albumin, fibronectin, PGE2 (p = 0.03), and gelatinase/type IV collagenase (p = 0.019), which began after 30 minutes of AngII infusion. Similar trends were not observed in dogs receiving saline solution alone. We therefore conclude that AngII-induced coronary vascular hyperpermeability is associated with an early release of PGE2 and gelatinase.

Pharmacokinetic interactions of nifedipine and quinidine

Several clinical investigations have been published regarding the interaction of nifedipine and quinidine. The results of these studies are contradictory. In vitro studies indicate that the 3-hydroxylation and N-oxigenation of quinidine appear to involve the P4503A4 family, a form of cytochrome that predominantly catalyzes the aromatization of nifedipine, too. The aim of our study was to investigate the effect of oral intake of 200 mg quinidine on the kinetics of 20 mg nifedipine as a retarded formulation and vice versa. Twelve healthy male volunteers between 18 and 40 years were treated. Each subject was studied on three occasions each separated by a one week washout period. Drug administration consisted of one oral dose of nifedipine (Adalat retard 20 mg), one oral dose of quinidine (Chinidin sulfuricum "Buchler" 200 mg) or a combination of both (20 mg nifedipine and 200 mg quinidine) in a randomised 3 way crossover. Administration of the test drugs in combination slightly increased the bioavailability of both--nifedipine [N] to 18% and quinidine [Q] to 16%--and decreased the clearance of both drugs. The results were not statistically significant. Based on our data, the combination of nifedipine and quinidine seems to lack a clinically relevant interaction.

Lack of effect of grapefruit juice on diltiazem bioavailability in normal subjects

The objective of the presented two-way randomized crossover study was to investigate whether repeated doses of grapefruit juice (200 ml at 0, 2, 4, 8 and 12 h) enhanced bioavailability of diltiazem (120 mg, orally) in nine healthy male subjects. Grapefruit juice did not alter AUC or cmax of diltiazem, whereas the half life experienced a slight, but statistically significant, increase (4.1 +/- = 1.2 vs 5.1 +/- 0.7 h). The N-demethyldiltiazem/diltiazem and deacetyldiltiazem/diltiazem ratios were not affected by grapefruit juice intake, which indicates that these metabolic pathways are not inhibited. Whereas bioavailability of some calcium channel antagonists of the dihydropyridine type metabolized via the same cytochrome P450 has been shown to be dramatically increased by grapefruit juice intake, the bioavailability of the benzothiazepine calcium channel antagonist diltiazem remained unchanged. This suggests that factors other than biotransformation may contribute to the clear effect of grapefruit juice on the bioavailability of those substances.

Influence of grapefruit juice on the pharmacokinetics of a slow release nifedipine formulation

The objective of this study was to investigate in a twoway randomized crossover whether repeated uptake of grapefruit juice (200 ml at 0, 2, 4, 8 and 12 h enhances bioavailability of a nifedipine (1) slow release formulation (20 mg) in ten healthy volunteers. Grapefruit juice increased the AUC and cmax of 1 statistically significantly by 103 (SD 73, range 48 to 265)% and 94 (SD 83, range -23 to 259)%, respectively. AUC of dehydronifedipine (2) was also higher during grapefruit phase, but to a lesser extent (mean increase 66, SD 106, range -30 to 236)%. Half lives of neither 1 nor 2 were altered by grapefruit juice. Because 2/1-ratio was not lowered by grapefruit juice in comparison to control, a selective inhibition of cytochrome P450 3A based on the presented in vivo data is not very likely. In the light of other reports concerning grapefruit juice induced increase in bioavailability our data contradict the assumption of a selective inhibition of only one cytochrome P450 subfamily. The observed effect could be clinically significant, especially if other factors affecting the elimination of 1 occur.

Grapefruit juice inhibits 7-hydroxylation of coumarin in healthy volunteers

The effect of grapefruit juice on the urinary excretion of 7-hydroxycoumarin after oral administration of 10 mg coumarin, as an index of cytochrome P450 dependent coumarin metabolism, has been investigated in an open, randomised cross over study in 13 healthy volunteers (7 female, 6 male). The percentage of 7-hydroxycoumarin found in urine was significantly decreased up to 8 h after simultaneous intake of 300 ml grapefruit juice. If the same volume of juice was swallowed 30 min prior to the administration of coumarin, 7-hydroxycoumarin excretion was delayed by up to 6 h. MRTexcr. of coumarin was 70% extended by coadministration of grapefruit juice. It appears that grapefruit flavonoids inhibit cytochrome P450 2A dependent metabolic pathways. The mechanism of cytochrome P450 inhibition by these flavonoids is still poorly understood.

Differential inhibition of coumarin 7-hydroxylase activity in mouse and human liver microsomes

Coumarin is 7-hydroxylated by the P450 isoform Cyp2a-5 in mice and CYP2A6 in humans. Various drugs, endogenous substances, plant substances and carcinogens, altogether about 90 chemicals, were evaluated as possible inhibitors of coumarin 7-hydroxylase (COH) activity in mouse microsomes. The effects of selected compounds on COH activity in human liver microsomes were also tested. The furanocoumarin derivatives methoxsalen (8-methoxypsoralen) and psoralen proved to be the most potent inhibitors of mouse COH activity (IC50 values 1.0 and 3.1 microM, respectively). The furanocoumarins bergapten (5-methoxypsoralen), isopimpinellin (5,8-dimethoxypsoralen), imperatorin and sphondin also effectively inhibited mouse COH activity (IC50 values 19-40 microM). Methoxsalen, isopimpinellin and metyrapone were also inhibitors in mice in vivo. Methoxsalen was a potent inhibitor of COH activity also in human liver microsomes, (IC50 value 5.4 microM), whereas bergapten, isopimpinellin and imperatorin had no effect. The imidazole antimycotic miconazole was a potent but non-specific inhibitor of COH activity. Several known substrates and inhibitors of members in the CYP1A, CYP2B, CYP2C, CYP2D and CYP3A subfamilies were poor inhibitors of COH activity. These results suggest that (i) the coumarin-type compounds in particular interact with the active sites of Cyp2a-5 and CYP2A6, and (ii) the active sites of Cyp2a-5 and CYP2A6 are structurally different, since a number of compounds inhibited mouse, but not human COH activity.