Practical Changes in Reference Services: A Case Study

Between 2018 and 2019, the librarians at the Strauss Health Sciences Library improved the efficiency and reach of their reference service by implementing four small-scale changes. These changes included revising the method of collecting statistics, creating FAQs, utilizing an appointment scheduler, and launching proactive chat. This case study will provide the background and research to support these changes, details on how the changes were implemented using Springshare tools, as well as the results and implications. Finally, the librarians will share their lessons learned along with recommendations for institutions interested in adopting similar changes.

[Infective endocarditis]

Colonization of native cardiac valves or polymer implants, e.g. valves, conduits, rings, electrode leads and polymer-associated endocarditis (PIE), by microorganisms, primarily gram-positive bacteria (infective endocarditis), constitutes a severe, prognostically unfavorable disease. Fever and in the majority of cases development of a valve regurgitant murmur are clinical landmark findings. The white blood cell count, erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) are regularly elevated. With a normal CRP level, infective endocarditis is extremely unlikely. Irrespective of body temperature, at least three blood cultures (aerobic and anaerobic) should be taken and if initiation of antimicrobial therapy is urgent, 1 h apart before therapy is initiated. Identification of the pathogen to the species level and testing antimicrobial susceptibility to antibiotics by a quantitative hemodilution test, not with agar diffusion tests, are obligatory. A minimum inhibitory concentration should be administered for antibiotics and usual combinations of antibiotics with an expected synergistic potential. Streptococci, staphylococci and enterococci are the most frequent causative organisms. Immediate initiation of transthoracic echocardiography (TTE) is mandatory followed by transesophageal echocardiography if imaging quality is poor, involvement of intracardiac implants is possible or TTE is insufficient to establish the diagnosis. An insufficiently long antimicrobial therapy promotes recurrent infections, thus a 4-week treatment is standard, while in special cases (e.g. PIE) treatment for 6 weeks should be the rule. If typical complications of infective endocarditis, such as uncontrolled local infection, systemic thromboembolism, central nervous involvement, development of a severe valve incompetence or mitral kissing vegetation in primary aortic valve endocarditis occur, urgent surgical intervention should be considered. If cardiac implants are involved, early surgical removal followed by a 6-week antimicrobial treatment is the rule. Adequate and timely diagnosis and treatment are the key to improve the overall prognosis.

Metastatic castration-resistant prostate cancer: integrating new learnings to optimise treatment outcomes

The approval or clinical evaluation of several new agents - cabazitaxel, abiraterone acetate, enzalutamide, sipuleucel-T, and radium-223 - has changed the management of patients with metastatic castration-resistant prostate cancer (mCRPC) prior to or after docetaxel-based chemotherapy significantly. All of these agents have resulted in a significant survival benefit as compared to their control group. However, treatment responses might differ depending on the associated comorbidities and the extent and the biological aggressiveness of the disease. Furthermore, treatment associated side effects differ between the various drugs. As new drugs become approved, new treatment strategies and markers to best select which patients will best respond to which drug are needed. It is the aim of the current article to: (1) summarize the data of established treatment options in mCRPC; (2) highlight new developments of medical treatment; (3) provide clinically useful algorithms for the daily routine and to (4) point out future developments of medical treatment.

[The "asymptomatic" patient with chronic acquired heart valve disease]

An intervention for chronic acquired valvular heart disease may either be indicated in symptomatic patients to relieve symptoms and improve quality of life or in asymptomatic patients to improve long-term prognosis, e.g., by preventing disease-related complications like chronic heart failure or arrhythmias. For proper action according to current guidelines, the systematic evaluation of symptoms related to the underlying valve disease is of utmost importance. If a discrepancy between symptoms reported or not reported by the patients and the severity of the valve disease is supposed, true absence of symptoms and exercise tolerance should be verified by spiroergometry. In the truly asymptomatic patient with a severe valvular lesion, preservation of myocardial adaption to the chronic volume or pressure overload should be tested utilizing appropriate imaging techniques like radionuclide ventriculography under exercise conditions. The proper evaluation of the functional status is of growing importance in our aging population with its sedentary lifestyle. In this context, the results of a survey should be kept in mind, which indicated that a significant proportion of patients still have interventions too late during the natural history of their valve disease with symptoms of congestive heart failure, arrhythmias, and the risk of sudden cardiac death persisting after a primarily successful valve repair or replacement.

[Metastasectomy for renal cell cancer]

BACKGROUND

Metastasectomy prior to or after systemic medical cancer treatment is performed within a multimodal therapeutic approach in metastatic renal cell cancer (mRCC) to improve the prognosis. The role of metastasectomy in mRCC is controversially discussed and the potential therapeutic benefit is unquantifiable. The purpose of the current review is to critically discuss the available data.

METHODS

A systematic literature search was carried out in the MedLinedatabase to identify original publications, review articles and editorials with respect to metastasectomy in mRCC and the current European guidelines were also taken into consideration.

RESULTS

Metastasectomy is one of the approaches for mRCC recommended in the guidelines in cases of stable disease for at least 3 months, complete resectability of all metastatic lesions independent of the anatomic localization and a good performance status of the patient. The median survival time varies between 35 and 55 months.

CONCLUSIONS

In mRCC metastasectomy is an indiviudal therapeutic approach which might be considered for limited metastatic disease and the presence of good prognostic risk factors to improve average survival time. Especially in renal cell cancer metastasectomy should be considered early.

Functional and oncologic outcomes of nephron-sparing surgery (NSS) for patients with renal cell carcinoma (RCC) greater than 4 cm in diameter

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Background: Organ preserving surgery represents the guideline recommended surgical treatment of choice for patients with small renal tumors ≤ 4cm in diameter. There are only few data in the literature with regard to the oncological and functional outcome of elective NSS in RCC larger than 4cm.

Methods: We retrospectively reviewed the charts of all patients who underwent elective NSS for RCC at our institution during 2004-2009. We identified 288 patients of whom 196 (68.1%) patients and 92(31.9%) patients underwent NSS for a tumor < 4cm (group 1) and a tumour ≥ 4cm (group 2), respectively. We analyzed tumor size, TNM-classification, OR time, surgical margins, complications, mortality, recurrences and metastases in both groups.

Results: We identified significant differences between group 1 and 2 for the following variables: mean tumor size (2.9 vs. 8.6cm, p = 0.03), necessity for warm ischemia (15.1% vs. 51%, p = 0.001), mean ischemia time (3.5 vs. 10.2 min, p = 0.002), need for endoluminal stenting due to involvement of the renal pelvis (0.5% vs. 24.2%, p = 0.001). Significantly less pT2 (12.7% vs. 29.7%, p = 0.03) and pT3 tumors (8.7% vs. 12%, p = 0.05) were identified in group 1 when compared to group 2. There were no significant differences with regard to mean OR time (61 vs. 74 min), positive surgical margins (1/192 vs. 1/92), hospital stay, and perioperative complications. There were no significant differences with regard to stage specific overall survival, cancer-specific survival and progression-free survival. There was no significant survival difference between NSS and radical nephrectomy.

Conclusions: NSS can be safely performed in RCC > 4 cm without increasing the frequency of treatment-associated complications or decreasing cancer-specific survival. NSS should represent the treatment of choice in all patients with RCC of 4-7cm in diameter if technically feasible.

No significant financial relationships to disclose.

Long-term therapy with sunitinib and sorafenib in patients with metastasizing renal cell carcinoma

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Background: Multitargeted tyrosine kinase inhibitors (MTKIs) constitute the established therapy in patients with metastasizing renal cell carcinoma. There are only few data concerning efficiency and safety, the reasons for a longterm response with good tolerability under MTKIs is still unknown.

Methods: We retrospectively analyzed the data of patients (pts.) under long-term therapy (>1 year) with sorafenib or sunitinib. Localization of metastases, number of cycles, sequence of therapy, treatment-associated toxicities, and frequency of dose reductions were our main focus of interest.

Results: 15 pts. (14 male, one female) with an mean age of 66,33 (44-81) years, were treated with 19,86 (12-35) cycles of sorafenib or sunitinib. 14/15 pts. underwent radical nephrectomy before the treatment. Localization of metastasis were as follows: pulmonary (9/15), hepatic (4/15), nodal (8/15), osseous (3/15), and pancreatic (2/15). In four pts. two or more organs were affected, in six pts. only one organ. As a first-line therapy nine pts. received sunitinib for 20.67 (12-35) cycles and one patient sorafenib for 44 cycles. For second line therapy two pts. were treated with sunitinib for 13 (12-14) cycles and three pts. with sorafenib for 23.33 (18-28) cycles. In five pts. a dose reduction of 25-50% was necessary due to significant treatment associated side effects, afterwards toxicities were tolerable under long term therapy (grade 1 in 10 pts.).

Conclusions: The results show, that longterm therapy with sunitinib or sorafenib is tolerable and efficacious independent on previous treatment. Prognostic factors concerning longterm response and low toxicity profile at a molecular biological level are still unknown, further investigations are of importance and are currently performed at our institution.

No significant financial relationships to disclose.

[Management of patients with heart valve diseases in 2008. What has changed in the last three decades?]

In Central Europe, the vast majority of patients with valvar heart disease today suffer from degenerative aortic valve stenosis or mitral regurgitation. Due to the aging population, the prevalence of both diseases is rapidly increasing. Despite older age at the time of intervention and more co-morbidities, perioperative mortality has been constantly low (about 3.5 % in Germany). Clinical symptoms reported by patients are often inappropriate to chose the optimal time for intervention. Myocardial contractility reserve is yet the most appropriate measure to assess myocardial adaption to the chronic pressure and/or volume overload. Awaiting myocardial maladaption is hampered by a significant worsening in prognosis. This is especially true for mitral regurgitation, where imaging techniques regularly fail to assess LV pump function due to the low left ventricular impedance. For patients with valvar heart disease requiring therapy with vitamin K antagonists, stability of oral anticoagulation therapy is essential to avoid thromboembolic as well as bleeding complications. For the majority of these patients, a target INR of 2.5 is optimal. INR point of care self management results in a more than 30 % reduction of adverse events.

New aspects of infective endocarditis

The current incidence of infective endocarditis (IE) is estimated as 7 cases per 100,000 population per year and continues to increase. The prognosis is significantly influenced by proper diagnosis and adequate therapy. In cases with unconfirmed IE, transesophageal echocardiography is the imaging technique of choice. Culture-negative endocarditis requires either termination of antimicrobial treatment initiated without mircobiological test results and reevaluation of blood samples or serological/molecular biological techniques to identify the causative organism. Antimicrobial therapy should be established only after quantitative sensitivity tests of antibiotics (minimal inhibitory concentrations, MIC) and guided by drug monitoring. In the first 3 weeks after primary manifestation, an index embolism is frequently followed by recurrencies. If vegetations can still be demonstrated by echocardiography after an embolic event, a surgical intervention should seriously be considered. Cerebral embolic events are no contraindication for cardiac surgery, as long as a cerebral bleeding has been excluded by cranial computed tomography immediately preoperatively and the operation is performed before a significant disturbance of the blood-brain barrier (<72 hours) has manifested. A significant prognostic improvement has also been demonstrated for patients with early surgical intervention suffering from myocardial failure due to acute valve incompetence, acute renal failure, mitral kissing vegetations in primary aortic valve IE, and in patients with sepsis persisting for more than 48 hours despite adequate antimicrobial therapy.

Tolerability and efficacy of multidose epoetin beta (Reco-Pen) for subcutaneous administration in patients with anemia due to renal failure

AIMS

To assess the tolerability, safety and efficacy of the epoetin beta multidose cartridge formulation, self-administered subcutaneously via a pen device (Reco-Pen), in adult patients with renal anemia.

METHODS

Patients receiving maintenance epoetin therapy were switched to the subcutaneous (SC) multidose formulation of epoetin beta (NeoRecormon). The frequency of adverse events, local tolerability, and changes in blood pressure and laboratory variables were recorded. Hematologic parameters, transfusion requirements and epoetin beta dosage were also assessed.

RESULTS

A total of 406 patients were entered in the intention-to-treat analysis. Mean treatment duration was 82.3 days. Fifty patients (12.3%) withdrew from the study; 14 (3.4%) discontinued because of adverse events. Treatment was well tolerated, with adverse events considered probably related to treatment in only 5 cases, and 1 case of local intolerability. There were no clinically significant changes in blood pressure or laboratory variables, and no changes in hematologic parameters or transfusion requirements. Unexpectedly, the epoetin beta dose was reduced by almost one-third in patients previously maintained on SC epoetin.

CONCLUSION

SC administration of this multidose epoetin beta formulation with the Reco-Pen device was well tolerated and effective. It is possible that the improved capacity to individualize dose may have contributed to the considerable reduction in SC epoetin beta dosage requirement.

[The Lyme carditis as a rare differential diagnosis to an anterior myocardial infarction]

An acute Lyme carditis affects about 0.3-4% of patients with Lyme borreliosis. The acute period of the disease may be associated with critical atrioventricular conduction abnormalities (complete heart block), supraventricular and ventricular arrhythmias as well a left ventricular failure. Normally, Lyme carditis is completely reversible. Therefore the prognosis largely depends on the management of the acute complications and early antibiotic therapy. Even if the symptoms are spontaneously reversible, antibiotic therapy should be applied to prevent a chronic cardiomyopathy and other manifestations of Lyme borreliosis. We report on a 47-year old patient with acute ECG changes initially suggesting an acute coronary syndrome. However, case history and the erythema migrans indicated an acute Lyme carditis which was confirmed serologically and by myocardial biopsy later.

The importance of secondary mitral valve involvement in primary aortic valve endocarditis; the mitral kissing vegetation

AIMS

Secondary involvement of the mitral valve is well documented in primary aortic valve endocarditis. A poorly considered, but probably important causative mechanism, involving both left-sided valves, is 'mitral kissing vegetation'. This results from large aortic vegetations prolapsing into the left ventricular outflow tract and making contact with the ventricular aspect of the anterior mitral leaflet thus causing secondary infection.

METHODS AND RESULTS

In 192 consecutive patients with aortic valve endocarditis, two to 18 (7.6+/-2.6) serial transoesophageal echocardiographic examinations were analysed per patient to demonstrate the development of mitral kissing vegetation on initially competent, morphologically normal mitral leaflets. In 19 patients (9.9%) with aortic valve endocarditis, mitral kissing vegetation was diagnosed within 11.6+/-9.0 (range 1-31) days following primary transoesophageal echocardiography. In all patients with mitral kissing vegetation, vegetations attached to aortic cusps were >6 mm. On hospital admission, patients with aortic valve endocarditis plus mitral kissing vegetation presented more often with a positive sepsis score, embolic events, renal failure and had larger aortic valve vegetations (9.9+/-3.3 vs 5.7+/-2.3 mm). Prognosis of aortic valve endocarditis plus mitral kissing vegetation was unfavourable (P<0.005) when compared to patients with aortic valve endocarditis alone.

CONCLUSION

In aortic valve endocarditis early echocardiographic detection of mitral kissing vegetation and timely surgery may preserve the mitral valve apparatus, and favourably influence the long-term prognosis.

Stroke is not a contraindication for urgent valve replacement in acute infective endocarditis

BACKGROUND AND AIM OF THE STUDY

A treatment dilemma arises when endocarditis is complicated by cerebral embolism. Secondary cerebral hemorrhagic complications may arise following suppression of coagulation during extracorporeal circulation. Extensive valvular vegetation is regarded as an indicator for urgent surgery. The study aim was to determine the relative risk of thromboembolic complications, and to analyze the prognostic influence of different treatment strategies following onset of these complications, in particular, secondary cerebral hemorrhagic events after urgent surgery.

METHODS

Between 1978 and 1993, endocarditis was diagnosed in 288 consecutive patients. Patients treated before 1982 (6.9%) were analyzed retrospectively. The remaining patients (93.1%) were followed prospectively (mean 4.3+/-1.7 years).

RESULTS

In 50 patients (17.4%), the clinical course was complicated by one embolism, and in 58 patients (20.2%) by recurrent embolisms. In total, 71% of all embolisms were cerebral events. The operated patients were categorized with regard to the time between recurrent thromboembolic events and cardiac surgery (<72 h, 3-8 days, and >8 days). The prognosis for patients operated within 72 h was significantly more favorable (p <0.0001) than for those treated medically. Patients undergoing cardiac surgery more than eight days after stroke, and those treated conservatively, had poor prognoses.

CONCLUSION

When endocarditis is complicated by stroke, it is recommended that cardiac surgery be performed within 72 h of the cerebral embolism, when the risk of secondary cerebral hemorrhage appears to be low. Cranial computed tomography is obligatory immediately before surgery in order to identify patients with early reperfusion hemorrhages due to spontaneous fragmentation of the thrombus. In these patients, cardiac surgery must be postponed because of the high risk of severe cerebral bleeding during extensive perioperative anticoagulation, and is only justified in the case of an otherwise unfavorable prognosis.

[Is Na+Ca(2+) exchanger expression altered in the endomyocardium of patients with chronic heart valve diseases parallel to myocardial dysfunction?]

BACKGROUND

Na(+)-Ca2+ exchanger (EXCH) is an important regulator of intracellular calcium homeostasis. To maintain a normal intracellular Ca2+ concentration, EXCH expression may be upregulated before the onset of end-stage heart failure. We tested for a correlation between the EXCH transcription level and the degree of myocardial dysfunction as well as the suitability of EXCH transcription as a molecular marker for early detection of a transition from adequate to inadequate myocardial adaptation to chronic pressure and/or volume overload in valvular heart disease (VHD).

METHODS

The level of EXCH transcription was analyzed in myocardial biopsies from eleven patients with aortic stenosis (AS), five with aortic regurgitation (AR) and six with primary mitral regurgitation (MR) of different hemodynamic severity and myocardial impairment using the quantitative rt-PCR technique. In addition, endomyocardial tissue from thirteen explanted hearts with end-stage heart failure and biopsies from seven individuals without heart disease were investigated.

RESULTS

The mean level of EXCH transcription in patients with AS was: 1.8 +/- 1.4 amol/ng total RNA, with AR: 1.9 +/- 0.8 amol/ng and with MR: 2.2 +/- +2.1 amol/ng. This was not from different controls (2.6 +/- 1.2 amol/ng total RNA). However, in myocardium from end-stage heart failure, EXCH transcription was increased fourfold amounting to 8.9 +/- 1.9 amol/ng total RNA. No difference in the EXCH transcription was found in VHD with respect to the degree of myocardial dysfunction: cardiac index (CI) > 3.5 l/min/m2 (EXCH 1.4 +/- 1.1 amol/ng total RNA); CI 3.5-2.4 (EXCH 2.5 +/- 1.8); CI < 2.4 (EXCH 1.8 +/- 1.0); EF-angio > 50% (EXCH 1.9 +/- 1.8); EF-angio < or = 50% (EXCH 1.9 +/- 0.9); EF-RNV > 50% (EXCH 2.4 +/- 1.8), EF-RNV < or = 50% (EXCH 1.7 +/- 1.0).

CONCLUSION

Myocardial EXCH transcription does not change parallel to the degree of myocardial dysfunction in VHD. Consequently, myocardial EXCH transcription does not appear to be suitable as a parameter indicating the transition from adequate to inadequate myocardial adaptation to chronic volume and/or pressure overload.

Is myocardial Na+/Ca2+ exchanger transcription a marker for different stages of myocardial dysfunction? Quantitative polymerase chain reaction of the messenger RNA in endomyocardial biopsies of patients with heart failure

OBJECTIVES

This study was designed to determine the stage of myocardial dysfunction at which an upregulation of the Na+/Ca2+ exchanger (EXCH) transcription takes place.

BACKGROUND

Because EXCH is an important regulator of intracellular calcium homeostasis, alterations in EXCH expression may occur before the onset of end-stage heart failure (HF) to maintain normal intracellular Ca2+ concentrations. We analyzed whether the EXCH transcription level is correlated to the degree of myocardial dysfunction and whether it can be a suitable molecular marker to define the transition to myocardial decompensation early on.

METHODS

By quantitative polymerase chain reaction technique, the level of EXCH transcription was analyzed in myocardial biopsies from 40 patients with various degrees of myocardial dysfunction due to valvular heart disease (VHD; n = 22) or dilated cardiomyopathy (DCM; n = 18). Additionally, biopsies from 7 individuals with excluded heart disease and explanted heart tissue from 13 patients with end-stage HF were investigated.

RESULTS

The level of EXCH transcription of controls (2.6 +/- 1.2 attomoles [amol]/ng total RNA) did not differ from that of patients with DCM (2.3 +/- 1.5 amol/ng) or VHD (2.1 +/- 1.5 amol/ng). No alteration in the EXCH transcription was found in VHD and DCM patients with respect to the severity of myocardial dysfunction. However, patients with end-stage HF showed a four-fold increase in EXCH transcription, amounting to 8.9 +/- 1.9 amol/ng (p < 0.05).

CONCLUSIONS

The upregulation in EXCH transcription either occurs very late in human heart failure or is a phenomenon of heart transplantation in end-stage HF. Consequently, myocardial EXCH transcription cannot be used as a marker for early myocardial decompensation.

[Is the estimation of the progression of valvular aortic stenosis possible?]

BACKGROUND AND OBJECTIVE

It is of great importance to assess progression of aortic valvar stenosis (AVS) when cardiac surgery is planned for other indications when established criteria for aortic valve replacement are not fulfilled at that moment. These considerations have often been ignored in prospective planning of treatment, necessitating a second cardiac surgical intervention just a few years later. The aim of this study was to establish criteria for estimating the rate of progression of AVS.

PATIENTS AND METHODS

Clinical, echocardiographic and haemodynamic data were analysed for 169 patients with aortic valvar stenosis (169 men, 88 women; mean age at first cardiac catheterization [CC] 55.2 +/- 15.7 years, at second CC 63.4 +/- 15.6 years.

RESULTS

The degree of AVS increases exponentially in relation to the extent of calcification (graded 0-3) and the fall in transaortic gradient (TG), from a TG > 0.6 mmHg/ml stroke volume and can be sufficiently predictable for clinical purposes. But neither age, sex nor the aetiology/pathology of the valvar defect have a sustained influence on the progression of AVS.

CONCLUSIONS

These data indicate that knowing the current reduction in TG and the degree of calcification makes it possible to assess the likely progression of previously asymptomatic AVS and thus greatly facilitate the decision of whether or not to combine aortic valve replacement with another indicated cardiac operation.

[Congenital tubular supravalvular aortic stenosis with massive coronary artery dilatation in a 35-year-old man]

Supravalvular aortic stenosis is a rare cause of left ventricular outflow obstruction in adults. It occurs as an isolated defect sporadically or on a hereditary basis with an autosomal dominant trait without further phenotypical anomalies, or as part of the Williams syndrome with mental retardation and multiple other anomalies. This lesion was proved to result from a defect of the elastin coding gene. Supravalvular aortic stenosis is frequently associated with cardiovascular defects, particularly of the peripheral pulmonary arteries, thoracic aorta, carotid, subclavian, and coronary arteries and the aortic valve. The coronary arteries are subject to an increased perfusion pressure leading to dilatation, tortuosity and accelerated arteriosclerosis. We give details of a 35-year-old patient in whom a previously asymptomatic supravalvular aortic stenosis is associated with an excessive dilatation of the right coronary artery and the left anterior descending coronary artery as well as an ostium stenosis of the left common carotid artery. The patient did not present any phenotypical anomalies of the Williams syndrome.

[Intracardiac thrombosis and consecutive thromboembolisms in patients with heart valve diseases: predisposition and concepts for prevention]

For patients with acquired heart valve lesions with increased risk for intracardiac thrombosis and consequent cardiogenic embolism there is consensus that oral anticoagulation therapy improves the overall prognosis. In mitral valve lesions anticoagulation is necessary after manifestation of atrial fibrillation or in cases of unstable sinus rhythm. The risk for thromboembolic events is increasing parallel to the enlargement of the left ventricular enddiastolic diameter, the left atrial size and dropping cardiac index. Spontaneous echo contrast (so called smoke like echos) indicate a prethrombotic state. In these cases an intensive anticoagulation is indicated. Aortic valve lesions require anticoagulation after manifestation of atrial fibrillation, the first manifestation of a thromboembolism or of spontaneous echo contrast. The risk for thromboembolism is increasing parallel to the reduction of left ventricular pump function. Life long oral anticoagulation therapy should be managed by use of the International Normalized Ratio (INR), and should be individualized taking into account patient related cardiac morphology and physiology, which may predispose to cardiogenic embolism. The target INR can range between 2.0 and 4.0.

[Thrombosis of prosthetic heart valves: diagnosis and management]

The incidence of prosthetic valve thrombosis (PVT) has been reported to be < 0.1-0.25%/year following isolated aortic valve replacement and < 0.1-2.5%/year after mitral valve implantation. In a consecutive series 10.3% of PVT occurred after an interruption of oral anticoagulant therapy for weeks or months, in 20.7% with inadequate low anticoagulation while in 34.5% of PVT cases intensity of the oral anticoagulant therapy showed significant ups and downs. There was an obvious increase of PVT incidences during the winter months, concomitant with increasing fibrinogen levels and plasma viscosity. The diagnosis of PVT can be made with a high specificity and sensitivity by analysis of the typical opening and closing clicks of the valve occluder. Parameters indicating chronic intravascular hemolysis, fluoroscopy and echocardiography are additionally helpful to confirm the diagnosis. The therapy of choice is prosthetic valve re-replacement. Systemic thrombolytic therapy may be an alternative in selected patient groups.

[Prospective study of the incidence, pathogenesis and therapy of spontaneous, by coronary angiography diagnosed coronary artery dissection]

Spontaneous coronary artery dissection is a rare cause of ischemic heart disease. Incidence, etiology and optimal treatment are ill-defined. Between July 1995 and December 1997, we prospectively identified 42 patients (36 men, six women, mean age 59 +/- 12 years) with spontaneous coronary artery dissection among 3803 consecutive angiographic examinations in which the diagnosis of coronary artery disease was established for the first time (incidence 1.1%). In comparison to the remaining study population with stable angina pectoris (8 cases of spontaneous coronary artery dissection among 2852 patients; incidence: 0.3%), the incidence of spontaneous coronary artery dissection was significantly higher in the patient subgroups with acute myocardial infarction (13/450; 2.9%) and with unstable angina pectoris or postinfarction angina (21/501; 4.2%). Dissection was most frequently located in the left anterior descending coronary artery (19 cases), followed by the right coronary artery (15 cases) and the left circumflex coronary artery (8 cases). Because of an ambiguous angiographic lesion appearance intravascular ultrasound imaging was performed in 13 patients to confirm the diagnosis. The presumed etiology of spontaneous coronary artery dissection was atherosclerotic plaque rupture in 35 cases, heavy physical exercise in four cases and hormonal influences related to pregnancy and contraception in one case. In two cases, no obvious risk factor could be identified. Therapy consisted of intracoronary stenting in 24 patients (including ten patients with acute myocardial infarction), coronary artery bypass grafting (CABG) in 8 patients and balloon angioplasty (PTCA) in seven patients. Three patients were treated conservatively. During a mean follow-up period of 13.5 +/- 9.9 months, two patients died and 31 patients remained entirely asymptomatic, including all patients who were treated with CABG. Restenosis developed in three patients after stent implantation (restenosis rate: 12.5%). Following primary PTCA, spontaneous coronary artery dissection recurred in two patients, one of whom subsequently died.

[Diagnostic approach and optimal treatment of aortic valve stenosis]

The slow progression of valvular aortic stenosis enables the left ventricular myocardium to adapt itself to the increasing afterload. When myocardial adaption is exhausted, surgical intervention is urgent, the prognosis, however, is already limited. To quantify the hemodynamic severity of aortic stenosis, transaortic pressure gradients (dp) measured by Doppler echocardiography or hemodynamically are inappropriate, because dp is significantly dependent on the transaortic flow volume. In severe aortic stenosis, despite constant narrowing of the aortic valve area, the reduced stroke volume results in decreasing transaortic pressure gradients. With aortic valve resistance or transaortic pressure loss (PL)--the quotient of pressure gradient and stroke volume--the hemodynamic severity of aortic stenosis can be described accurately. If PL is known, a decompensated aortic stenosis (PL > 1 mm Hg/ml) may be differentiated from myocardial failure of another etiology and a concomitant left ventricular outflow tract obstruction. With respect to medical therapy, the prevention of bacterial endocarditis and thromboembolic complications is important. Knowing the potential danger of syncopies and ventricular arrhythmias during exercise with increasing severity of aortic stenosis, patients have to be informed about their limited functional capacity. The occurrence of typical symptoms during the natural history of chronic aortic stenosis (e.g. dizziness, syncopes, angina pectoris, arrhythmias) manifestation of ST-T-alterations or silent myocardial ischemias and demonstration of an inadequate myocardial adaptation to the chronic pressure overload in asymptomatic patients are accepted indications for a surgical intervention. If the indication for surgery remains uncertain, stress tests (e.g. radionuclidventriculography) may be performed to demonstrate an exhausted myocardial adaptation. If the PL and the severity of aortic valve/anulus calcification is known, the progression of a chronic aortic stenosis can be estimated. This might be important, if a cardiosurgical intervention has to be performed for other indications and aortic stenosis is co-existent but does not require an intervention at that time. For prognostic reasons myocardial decompensation due to aortic stenosis is an indication for an urgent surgical intervention. Attempts for medical recompensation or bridging strategies (e.g. balloon valvotomy) worsens the prognosis significantly.

[Optimal management of primary and secondary mitral regurgitation]

While morphologic alteration of parts of the mitral valve apparatus (ventricular wall, papillary muscles, chordae tendineae, valve annulus and leaflets) may result in a loss of its functional integrity (primary mitral regurgitation, MR) mitral annulus dilatation following left ventricular enlargement or change in chamber geometry and consecutive opening of the angle between papillary muscles and valve annulus cause secondary MR. Irrespective of these etiologies MR is chronically progressive and much more than the severity of MR the grade of myocardial adaptation to the chronic volume overload is of prognostic significance. Inadequate myocardial adaptation is demonstrated by an increase of the echocardiographically determined radius (r) to wall thickness (Th) ratio (r/Th > 3.0), indicating increasing left ventricular wall stress or by an insufficient increase of the left ventricular ejection fraction (< or = 5% of resting values) under exercise conditions, e.g. with radionuclide angiocardiography (RNV). Stressecho may replace RNV in the future for this indication. Actually, stress echo is not reliable to determine changes in left ventricular ejection fraction at rest versus exercise because of systematic errors and error reproduction. There are preliminary reports on biochemical markers like noradrenaline or tumor necrosis factor alpha being helpful to determine the breakdown of myocardial adaptation mechanisms. Surgical intervention is indicated in chronic MR irrespective of the hemodynamic severity, if myocardial adaptation is inadequate. If mitral reconstruction, the surgical technique of choice, remains insufficient to restore normal valve function, mitral valve replacement with preservation of the subvalvular apparatus is unavoidable. For a deceleration of the progressive volume overload in chronic MR for which a surgical intervention is not yet indicated, a long-term afterload reducing medical therapy preferably with long acting ACE-inhibitors seem to be prognostically favorable.

[Emergency heart valve replacement after acute cerebral embolism during florid endocarditis]

BACKGROUND

The indication for urgent cardiac surgical interventions in patients with active infective endocarditis has to be considered carefully following thromboembolic events, because of the high recurrence rate of such complications. In the case of brain embolisms the prognostic benefit of urgent surgery has been discussed controversially as effective anticoagulation during open heart surgery may result in secondary cerebral hemorrhages.

PATIENTS AND METHODS

Between 1978 and 1993 infective endocarditis (IE) was proven in 288 consecutive and prospectively followed patients (131 females, 157 males; mean age 53.6 +/- 8.7 [9 to 81] years). To analyze potential benefits and risks of an urgent surgical intervention early after embolic cerebral infarction, cumulated survival rates were calculated for patients with and without surgical intervention with special reference to incremental risk factors and the timing of surgery.

RESULTS

In 50 patients (17.4%) the clinical course was complicated by one, and in 58 patients (20.2%) by recurrent embolic events. In 80% the first embolism occurred within 33 days following the first manifestation of typical signs and symptoms of IE. 80% of recurrent events were observed within 32 days following the initial embolism. 71% of all embolic events were cerebral. In patients with cerebral embolism corroborated by computed tomography (CCT), the clinical course was complicated by intracranial hemorrhage in 12.5% while it was only 1.5% for patients without cerebral embolism. Because of a lack of therapeutic alternatives, 22 of 49 patients with recurrent embolic events, of which at least one was cerebral, underwent urgent cardiac surgery within 4 to 366 hours after the first cerebral manifestation. The cumulated survival rate of patients operated within 72 hours after the initial cerebral embolism was significantly more favorable (p < or = 0.000) than for unoperated patients or those who were operated after more than 8 days.

CONCLUSION

An embolic event during IE carries a more than 50% risk of recurrence. In patients with short duration of signs and symptoms of IE and postembolic echocardiographic demonstration of persistent vegetations the probability is > 80%. At least for those patients urgent surgical intervention to remove the source of infection and embolic hazard seems to be beneficial. Surgical intervention using the heart-lung-machine should be performed within 72 hours. Such early timing results in a significant lower rate of secondary cerebral hemorrhages (p < or = 0.00) than a postponed operation. To exclude early reperfusion hemorrhage due to spontaneous thrombus fragmentation, CCT should be repeated directly preoperatively.

Anaemia- and malaria-attributable low birthweight in two populations in Papua New Guinea

We studied 7300 singleton births in the highlands and 4881 in coastal Papua New Guinea in order to examine the separate contribution of anaemia or malaria to low birthweight. The highland sample was selected from a non-malarious area (Goroka) and the coastal sample from an area with perennial malaria transmission (Madang). There was an approximately three-fold increased risk of low birthweight (< 2500 g) in live-births in Madang compared to Goroka. The prevalence of anaemia in the two areas was strikingly different, with 29.2% of Goroka and 89.0% of Madang women anaemic. There was a trend towards increased low birthweight with decreasing haemoglobin levels in both areas, but this was significant only for Madang. It was assumed that for a given haemoglobin level the increased low birth weight percentage in Madang compared to Goroka was due to malaria exposure, and on this basis relative risk values were estimated for the effect of malaria exposure on low birthweight. Using this approach separate estimates for anaemia and malaria population-attributable risk for low birth weight in Madang were calculated. These indicated that up to 40% of low birthweight babies born in malarious areas may be attributable to malaria and less than 10% attributable to severe anaemia (Hb < 7.0 g dl-1). The magnitude of the malaria effect estimated in this analysis places a high priority on malaria control in pregnancy as a strategy for improving birthweight and child survival.

[Acute myocardial infarct caused by a muscle bridge of the anterior interventricular ramus: complicated course with vascular perforation after stent implantation]

A 47-year-old male patient was admitted to our hospital with acute anterior myocardial infarction. Immediate coronary angiography was carried out, which showed proximal occlusion of the left anterior descending artery (LAD). After mechanical recanalization, a reduction in vessel caliber at the site of occlusion was visible, and balloon angioplasty with consecutive stent implantation because of vessel wall dissection was performed. After the procedure, diameter reduction of the entire vessel segment distal to the stent and muscular bridging with subtotal systolic obliteration of the LAD and one diagonal branch were demonstrated. Diastolic coronary flow did not appear to be limited (TIMI 3). Dipyridamole-thallium cardiac imaging revealed an incomplete perfusion defect of the anteroseptal region and a reversible perfusion reduction of the anterolateral region. For definitive treatment, we decided to implant a 3.0 mm-stent at the site of muscular bridging. Although balloon sizing was adapted to the diameter of the proximal reference segment, measured by quantitative coronary angiography, coronary perforation into the right ventricular outflow tract due to balloon oversizing in the distal dilation segment occurred. The patient remained asymptomatic at rest as well as under exercise testing, and hemodynamics remained stable. Coronary re-angiography after 1 week demonstrated a persistent fistula with complete opacification of the LAD and normal coronary flow (TIMI 3). Within the following 3 months, the coronary fistula closed spontaneously.

CONCLUSIONS

Muscular bridging is a rare cause of acute myocardial infarction. Balloon angioplasty and stent implantation in the bridged segment may be complicated by coronary artery perforation due to balloon oversizing. Risks and benefits of this therapeutic option, therefore, have to be critically evaluated, and careful selection of balloon size using measurements of proximal and distal reference diameter assessed by intravascular ultrasound is recommended. Coronary artery perforation into the myocardium with subsequent development of a fistula may be treated conservatively as long as the patient remains asymptomatic. The frequency of spontaneous closure of the fistula is high.

[Severe HELLP syndrome with temporary kidney and lung failure]

This report is on a severe case fo a HELLP-syndrome (H haemolysis, EL elevated liver enzymes, and LP low platelets). A 32-year old gravida developed severe preeclampsia with epigastric pain at 33 weeks' gestation. During a few hours post partum she showed disseminated intravascular coagulation (DIC) and required intensive care. The severe HELLP-syndrome was combined with a fast increasing acute respiratory distress syndrome (ARDS) and acute oligo-anuric renal failure. She was treated in the intensive-care unit for several days with artificial respiration, 10 acute haemodialyses, 4 plasma exchanges with fresh-frozen plasma and many blood and platelet transfusions. An early Caesarean section and treatment in the intensive care unit managed to turn the otherwise complicated progression of the disease. It is pointed out that plasma exchange with fresh-frozen plasma is a rarely employed treatment.

Late prosthetic valve endocarditis

Prosthetic valve endocarditis remains an extremely serious complication, with a low but increasing incidence. 'Late' endocarditis, occurring more than 60 days after surgery, is relatively infrequently associated with staphylococci, Gram-negative bacteria and fungi so characteristic of the endocarditis that occurs earlier. A probable source of infection can be found in 25%-80% of patients, the most frequent causes being dental procedures, urological infections and interventions, and indwelling catheters. The most common organisms are S. epidermidis, S. aureus, viridans streptococci and enterococci. The general principles of antibiotic treatment are similar to those for native valve endocarditis, but antibiotic treatment needs to be more prolonged and dosages should be used which result in maximal, nontoxic concentrations. Oral anticoagulants should be stopped and replaced by intravenous heparins. Surgical reintervention is called for if there are large highly mobile vegetations in the mitral position or within 72 h if there are cerebral thrombo-embolic episodes.

[Brain abscess in patients with cyanotic heart defects]

As a result of hypoxia following right-to-left shunts, cerebral bacterial spreading and an altered blood-brain-barrier permeability, brain abscesses (BA) are typical complications in patients with cyanotic congenital heart disease. In 483 prospectively followed patients the incidence of BA was 0.45%/year. It was higher (0.57%/year) for patients with tetralogy of Fallot where the cumulative risk within the first two decades of life was 12.1 +/- 1.7%. The risk of BA complicating cyanotic heart disease is inconstant and continuously increasing up to approximately age 12 (instantaneous risk at that time: 1.75 +/- 0.12%), decreasing thereafter. With respect to etiology, infectious endocarditis, infections per continuitatem, bacterial meningitis, bacterial lung diseases with intrapulmonary shunts, and thromboembolic complications of systemic infections have to be differentiated. The stepwise diagnosis includes CCT to demonstrate the typical contrast enhancement and a lumbar puncture which shows granulocytic pleocytosis. If the cerebral spinal fluid fails to demonstrate the typical findings, cerebral angiography may be necessary to exclude a malignant vascularized neoplasma. In cases of doubt, stereotactic cerebral biopsy should be performed. Optimal antibiotic therapy after determining the minimal bactericidal concentration and combination of antibiotics is of utmost prognostic significance. Cranial computed tomography should be repeated after 6, 14, and 24 days. Infections resistant to antibiotics may necessitate local instillation of antibiotics.