Klappenvitien im Erwachsenenalter

Short-Term Changes in Arterial Stiffness Measured by 2D Speckle Tracking in Patients Undergoing Transcatheter Aortic Valve Implantation

Arterial stiffness has received increasing interest as a cardiovascular marker in patients with aortic valve stenosis (AS). So far, studies on the impact of aortic valve replacement (AVR) on arterial stiffness have been equivocal. Two-dimensional speckle tracking (2DST) is a novel, non-invasive method to measure the motion of the vessel wall. In this prospective observational study, we aimed to assess the change in arterial stiffness of the common carotid artery (CCA) measured by 2DST in patients undergoing transcatheter aortic valve implantation (TAVI). A total of 47 patients were included in the study (age 80.04 ± 6.065 years). Peak circumferential strain (CS) was significantly improved after TAVI (4.50 ± 2.292 vs. 5.12 ± 2.958, p = 0.012), as was the peak strain rate (CSR) (0.85 ± 0.567 vs. 1.35 ± 0.710, p = 0.002). Body mass index (BMI), mean arterial pressure (MAP) and hemodynamic parameters were associated with this change. 2DST results did not correlate with aortic pulse wave velocity (aPWV) or augmentation index normalized to heart rate (AIx@75), suggesting a distinct difference between arterial stiffness of the CCA and other stiffness parameters. 2DST seems to be a promising new tool to assess arterial stiffness in TAVI patients.

[Anticoagulation after heart valve replacement]

In patients after mechanical heart valve replacement anticoagulation is required for the prevention of thrombotic and thromboembolic events. In this setting oral anticoagulation can only be performed with vitamin K antagonists (VKA), while currently all available non-vitamin K dependent oral anticoagulants (NOAC) are contraindicated in patients with mechanical heart valve replacement. This review deals with anticoagulation in patients with mechanical heart valve replacement as well as coagulation inhibition after bioprosthetic or percutaneous valve replacement. In addition, recommendations are given for antithrombotic medication in patients with mechanical heart valve replacement in various clinical scenarios.

Temporal Views of Flattened Mitral Valve Geometries

The mitral valve, one of the four valves in the human heart, controls the bloodflow between the left atrium and ventricle and may suffer from various pathologies. Malfunctioning valves can be treated by reconstructive surgeries, which have to be carefully planned and evaluated. While current research focuses on the modeling and segmentation of the valve, we base our work on existing segmentations of patient-specific mitral valves, that are also time-resolved ( 3D+t) over the cardiac cycle. The interpretation of the data can be ambiguous, due to the complex surface of the valve and multiple time steps. We therefore propose a software prototype to analyze such 3D+t data, by extracting pathophysiological parameters and presenting them via dimensionally reduced visualizations. For this, we rely on an existing algorithm to unroll the convoluted valve surface towards a flattened 2D representation. In this paper, we show that the 3D+t data can be transferred to 3D or 2D representations in a way that allows the domain expert to faithfully grasp important aspects of the cardiac cycle. In this course, we not only consider common pathophysiological parameters, but also introduce new observations that are derived from landmarks within the segmentation model. Our analysis techniques were developed in collaboration with domain experts and a survey showed that the insights have the potential to support mitral valve diagnosis and the comparison of the pre- and post-operative condition of a patient.

Impact of concomitant mitral regurgitation on transvalvular gradient and flow in severe aortic stenosis: a systematic ex vivo analysis of a subentity of low-flow low-gradient aortic stenosis

AIMS

Evaluation of aortic stenosis (AS) is based on echocardiographic measurement of mean pressure gradient (MPG), flow velocity (Vmax) and aortic valve area (AVA). The objective of the present study was to analyse the impact of systemic haemodynamic variables and concomitant mitral regurgitation (MR) on aortic MPG, Vmax and AVA in severe AS.

METHODS AND RESULTS

A pulsatile circulatory model was designed to study function and interdependence of stenotic aortic (AVA: 1.0 cm², 0.8 cm² and 0.6 cm²) and insufficient mitral prosthetic valves (n=8; effective regurgitant orifice area [EROA] <0.2 cm² vs. >0.4 cm²) using Doppler ultrasound. In the absence of severe MR, a stepwise increase of stroke volume (SV) and a decrease of AVA was associated with a proportional increase of aortic MPG. When MR with EROA <0.2 cm² vs. >0.4 cm² was introduced, forward SV decreased significantly (70.9±1.1 ml vs. 60.8±1.6 ml vs. 47.4±1.1 ml; p=0.02) while MR volume increased proportionally. This was associated with a subsequent reduction of aortic MPG (57.1±9.4 mmHg vs. 48.6±13.8 mmHg vs. 33.64±9.5 mmHg; p=0.035) and Vmax (5.09±0.4 m/s vs. 4.91±0.73 m/s vs. 3.75±0.57 m/s; p=0.007). Calculated AVA remained unchanged (without MR: AVA=0.53±0.04 cm² vs. with MR: AVA=0.52±0.05 cm²; p=ns). In the setting of severe AS without MR, changes of vascular resistance (SVR) and compliance (C) did not impact on aortic MPG (low SVR and C: 66±13.8 mmHg and 61.1±20 mmHg vs. high SVR and C: 60.9±9.2 mmHg and 71.5±13.5 mmHg; p=ns) In concomitant severe MR, aortic MPG and Vmax were not significantly reduced by increased SVR (36.6±2.2 mmHg vs. 34.9±5.6 mmHg, p=0.608; 3.89±0.18 m/s vs. 3.96±0.28 m/s; p=ns).

CONCLUSIONS

Systemic haemodynamic variables and concomitant MR may potentially affect diagnostic accuracy of echocardiographic AS evaluation. As demonstrated in the present study, MPG and Vmax are flow-dependent and significantly reduced by a reduction of forward SV from concomitant severe MR, resulting in another entity of low-flow low-gradient aortic stenosis. In contrast, calculated AVA appears to be a robust parameter of AS evaluation if severe MR is present. Changes of SVR and C did not affect the diagnostic accuracy of AS evaluation.

Can postoperative mean transprosthetic pressure gradient predict survival after aortic valve replacement?

Background

In this study, we sought to determine the effect of the mean transprosthetic pressure gradient (TPG), measured at 6 weeks after aortic valve replacement (AVR) or AVR with coronary artery bypass grafting (CABG) on late all-cause mortality.

Methods

Between January 1998 and March 2012, 2,276 patients (mean age 68 ± 11 years) underwent TPG analysis at 6 weeks after AVR (n = 1,318) or AVR with CABG (n = 958) at a single institution. Mean TPG was 11.6 ± 7.8 mmHg and median TPG 11 mmHg. Based on the TPG, the patients were split into three groups: patients with a low TPG (<10 mmHg), patients with a medium TPG (10–19 mmHg) and patients with a high TPG (≥20 mmHg). Cox proportional-hazard regression analysis was used to determine univariate predictors and multivariate independent predictors of late mortality.

Results

Overall survival for the entire group at 1, 3, 5, and 10 years was 97, 93, 87 and 67 %, respectively. There was no significant difference in long-term survival between patients with a low, medium or high TPG (p = 0.258). Independent predictors of late mortality included age, diabetes, peripheral vascular disease, renal dysfunction, chronic obstructive pulmonary disease, a history of a cerebrovascular accident and cardiopulmonary bypass time. Prosthesis–patient mismatch (PPM), severe PPM and TPG measured at 6 weeks postoperatively were not significantly associated with late mortality.

Conclusions

TPG measured at 6 weeks after AVR or AVR with CABG is not an independent predictor of all-cause late mortality and there is no significant difference in long-term survival between patients with a low, medium or high TPG.

Cardiac stem cells in patients with heart disease

The heart has been regarded as a terminally differentiated organ for decades. There are numerous indicators for the potency of myocardial regeneration, which opens up new avenues for the treatment of heart disease. Cardiac stem cells (CSCs) have been discovered in the human heart and they play a vital role in myocardial regeneration. This review discusses the distribution, properties and proliferation of CSCs in the myocardium of patients with heart disease. Additionally, the potency of myocardial regeneration in patients with heart disease is discussed.

[Transcutaneous aortic valve implantation]

Due to increasing life expectancy in the coming decades the number of elderly patients with aortic valve stenosis (AS) and various concomitant diseases will increase. Conventional surgical aortic valve replacement represents the treatment of choice in patients with severe and symptomatic AS. Transfemoral and transapical aortic valve implantation (T-AVI) has evolved as a standard procedure for patients with severe AS who are technically inoperable or at very high risk for surgical valve replacement. The T-AVI approach has been shown to be superior to the standard medical treatment in these high-risk patients. All patients to be considered for T-AVI should be discussed in a consensus conference consisting of cardiac surgeons and cardiologists (heart team).

Percutaneous and surgical treatment of mitral valve regurgitation

BACKGROUND

Mitral valve regurgitation is the second most common clinically relevant valvular heart disease in adults, with an incidence of about 2% to 3% per year. Surgical mitral valve repair is the treatment of choice. Recent years have seen major advances in minimally invasive mitral valve surgery. Several new catheter-based techniques are now being clinically evaluated, including percutaneous endovascular mitral valve repair with a mitral clip.

METHOD

This review is based on a selective review of the literature and on the authors' clinical experience.

RESULTS

Minimally invasive and reconstructive techniques for mitral valve surgery have come into more common use in recent years. In Germany, more than 50% of all mitral valve defects are now treated with a valve-preserving repair procedure. At the same time, percutaneous techniques have been developed that enable reduction of mitral regurgitation in the cardiac catheterization laboratory, without surgery. The implantation of a mitral clip is the sole currently approved technique of this type. In a recently published, randomized comparative clinical trial (EVEREST II), it was found to be safer, but less effective, than surgery.

CONCLUSION

Mitral valve surgery remains the treatment of choice for severe mitral regurgitation. For patients at high risk from surgery, and particularly those with severe heart failure, the implantation of a mitral clip is a safe and feasible treatment option.

[Cardiac syncope : diagnosis and therapy]

The second most frequent category of syncope is cardiac syncope. In contrast to syncope of noncardiac causes, the 1-year mortality of patients presenting with cardiac syncope without treatment is as high as 33%. Therefore, immediate diagnosis and treatment are necessary. Bradyarrhythmias or tachyarrhythmias are the most common causes of cardiac syncope. In many cases, an initial evaluation including history, physical examination, and electrocardiogram identifies the cause of syncope, so that specific treatment can be initiated immediately. In the remainder of cases, implantable loop recorders are useful to identify arrhythmias, while the presence or absence of structural cardiac disease is diagnosed by echocardiography. Syncope due to arrhythmias is typically treated with implantation of a pacemaker or an implantable cardioverter-defibrillator; treatment of syncope of other cardiac causes requires therapy of the underlying heart disease.

[Prevalence and clinical significance of incidental cardiac findings in non-ECG-gated chest CT scans]

BACKGROUND

The purpose of this study was to evaluate the prevalence and clinical significance of incidental cardiac findings in non-ECG-gated chest CT.

PATIENTS AND METHODS

Non-ECG-gated chest CT examinations of 300 patients were retrospectively analyzed for incidental cardiac findings. Subsequently, these findings were evaluated for their clinical relevance by a cardiologist.

RESULTS

A total of 107 out of 300 examined patients had 174 incidental cardiac findings including coronary calcification (90), aortic/mitral valve calcification (42), iatrogenic changes (23), pericardial effusion (6), dilatation of the heart (4), myocardial changes (3), thrombus in the left ventricle (2), constrictive pericarditis (2) and atrial myxoma (1). Of the cardiac findings 51% were described in the written report and in 53 out of the 107 patients the cardiac findings were unknown. Newly detected incidental findings from 8 patients were rated as clinically significant: pericardial effusion (4), constrictive pericarditis (1), thrombus in the left ventricle (1), atrial myxoma (1) and dilatation of the heart (1).

CONCLUSION

Incidental cardiac findings are frequent in non-ECG-gated chest CT and may have a high clinical relevance.

[Disappearing borders between cardiology and cardiothoracic surgery: status quo]

Cardiology and cardiothoracic surgery are closely related so that collaboration and communication are required to offer optimal therapy for patients. During the last decades many innovations have reduced the borders between cardiology and cardiothoracic surgery. Today, cardiologists may perform coronary interventions with good results that would have previously been the domain of coronary bypass surgery. In addition new valvular interventions have been developed, such as transfemoral or transapical aortic valve implantation and endovascular mitral valve reconstruction. New developments in cardiothoracic surgery have led to less invasive procedures and many surgical procedures can now be performed with minimally invasive techniques and without a cardiopulmonary bypass. To enable optimal therapy for patients, closer collaboration between cardiologists and cardiothoracic surgeons is required setting the stage for individualized therapy in the future.

Heart valve surgery today: indications, operative technique, and selected aspects of postoperative care in acquired valvular heart disease

BACKGROUND

Surgery plays a central role in the management of acquired valvular heart disease. The optimal diagnostic evaluation, surgical treatment, and postoperative care of these patients are only possible through a cooperative effort of the primary care physician, the cardiologist, and the cardiac surgeon.

METHODS

The literature was selectively searched for information on surgical indications, operative techniques, and postoperative care in acquired valvular heart disease. Evidence-based guidelines and treatment recommendations were also taken into account.

RESULTS

A wide variety of techniques and implants are now available for the surgical treatment of acquired valvular heart disease. If they are used in evidence-based fashion, the perioperative mortality is low and the long-term outcome is favorable.

CONCLUSIONS

The volume of surgery for acquired valvular heart disease in Germany has increased substantially in recent years, from 25,495 cases in 2002 (corresponding to 26.5% of all heart operations in that year) to 33,412 in 2007 (36.5% of all heart operations). The causes for this include both demographic changes and the availability of new, less invasive surgical techniques that yield better results in elderly and/or multimorbid patients. Because of these new techniques, the indications for surgery have widened, while the results have remained favorable.

[Anticoagulation and thrombophilia in pregnancy]

A review of coagulation disturbances during pregnancy and the current management of the anticoagulated patient with heart valve prostheses, atrial fibrillation, and thromboembolic events is presented. All patients with mechanical heart valve prostheses require life-long oral anticoagulation with coumarin or one of its derivatives. Recommendations for the treatment and prevention of thromboembolic events are discussed. The advantages and disadvantages of three different treatment approaches to anticoagulation during pregnancy are discussed and recommendations for the management in different situations are outlined with delineation of specific risks for the mother and the fetus.

Eight-year follow-up after prospectively randomized implantation of different mechanical aortic valves

OBJECTIVE

The aim of this prospectively randomized study was to evaluate the hemodynamic and functional outcomes after aortic valve replacement with three different bileaflet mechanical valves.

METHODS

From March 1996 to August 1998, 300 consecutive patients were randomly assigned to receive ATS (n = 100), Carbomedics (n = 100), or St Jude Medical Hemodynamic Plus (n = 100) mechanical aortic valve replacement. There were no significant differences regarding patient age (61 +/- 8 years), gender, NYHA, aortic valve pathology, ventricular morphology, ejection fraction and requirement for additional procedures at implant. Mean follow-up extends to 95 +/- 21 months at a total of 2,891 patients years and is in 95.3% complete.

RESULTS

Implanted valve sizes were comparable at 24 +/- 2 mm (ATS), 23.7 +/- 1.6 mm (CM), and 23.6 +/- 1.9 mm (SJMHP) (NS). Follow-up results were: transvalvular flow velocities 2.3/2.3/2.2 m/s, ejection fraction 64/59/63%, trivial transvalvular incompetence 3/3/2; paravalvular leak 2/3/2; freedom of reoperation 100/99/99%, NYHA functional status 1.5/1.8/1.6, overall survival 86.4/82.8/80.6%, freedom from thrombembolic events 100/96/98%, freedom from hemorrhage 100/100/99%, freedom from all valve related events was 100/96/98%; respectively (NS). There were no episodes of endocarditis. Ninety-four percent of the patients were satisfied with the procedure enjoying an enhanced daily life activity.

CONCLUSIONS

There are no clinically relevant differences among the tested bileaflet aortic valves. Regardless of valve type, there was a rather low complication rate in this relatively young population. All three bileaflet prostheses are well suited for aortic valve replacement.

Durability of bioprosthetic cardiac valves

INTRODUCTION

The choice of type of heart valve prosthesis is determined by the patient's age since bioprostheses have a limited lifespan. This article reviews current recommendations and the literature on cardiac valve replacement.

METHODS

Selective literature search in Medline/PubMed back to 1996 and review of current national and international recommendations from specialist societies.

RESULTS

The recommendations guiding the type of heart valve replacement have been revised in recent years. Of particular interest are the new generation of biological prostheses with extended durability, a growing use of stentless bioprostheses, a decrease in mortality of reoperation and an increase in life expectancy. Comorbidities such as chronic renal insufficiency or chronic atrial fibrillation are no longer contraindications to bioprosthesis. The number of heart valve replacements in recent years rose despite a concomitant increase in valve repairs. Aortic valves are being increasingly replaced by bioprostheses.

DISCUSSION

The choice of heart valve prosthesis should be tailored to each patient taking into account the patient's age, life expectancy, comorbidities, and life style. Different decisions may be made now than those based on earlier recommendations resulting in an individualized treatment, in patients over the age of 65 or 70.