Imaging for planning of transcatheter aortic valve implantation.

Transcatheter aortic valve implantation (TAVI) has proven to be the standard of care for patients with prohibitive and high operative risk; today, it is considered a reasonable alternative to surgical aortic valve replacement in intermediate-risk patients. As indications for TAVI move toward patients at lower risk, safety aspects are becoming even more important. Furthermore, adequate patient selection is key for predictable procedural success with minimal complications, translating into an optimal clinical outcome. Decisions on valve type and size as well as on the access route are based on multimodality imaging including echocardiography, multislice computed tomography, and cardiac catheterization with peripheral angiography. This combination of multiple imaging modalities provides the best picture of a patient's anatomical and physiological suitability for the TAVI procedure. Yet, the reliability of preprocedural imaging is influenced by the quality of the images, which should be as high as possible, and both image acquisition and interpretation should be performed in a standardized manner. This article provides a concise overview of standardized multimodality imaging for the preprocedural planning and assessment of patients undergoing TAVI.

The minimally invasive MitraClip™ procedure for mitral regurgitation under general anaesthesia: immediate effects on the pulmonary circulation and right ventricular function.

A relatively new minimally invasive cardiological procedure, called the MitraClip(™), does not require sternotomy and may have a number of advantages compared with open mitral valve surgery, but its acute impact on the pulmonary circulation and right ventricular function during general anaesthesia is unclear. We prospectively assessed the effects of the MitraClip procedure in 81 patients with or without pulmonary hypertension (defined as mean pulmonary artery pressure > 25 mmHg), who were anaesthetised using fentanyl (5 µg.kg(-1)), etomidate (0.2-0.3 mg.kg(-1)), rocuronium (0.5-0.6 mg.kg(-1)) and isoflurane. Placement of the MitraClip led to a 60% increase in mean (SD) right ventricular stroke work index (from 512 (321) to 820 (470) mmHg.ml.m(-2), p < 0.0001), while mean (SD) pulmonary vascular resistance index decreased by 24% (522 (330) to 399 (244) dyn.s.cm(-5), p < 0.0001), and mean (SD) pulmonary artery pressure decreased by 10% (30 (8) to 27 (8) mmHg, p < 0.0001). Patients with pulmonary hypertension experienced a similar decrease in mean pulmonary artery pressure compared with those without, and they also had a slight reduction in mean (SD) pulmonary artery occlusion pressure (22 (6) down to 20 (6) mmHg, p = 0.044). We conclude that successful MitraClip treatment for mitral regurgitation acutely improves right ventricular performance by reducing right ventricular afterload, regardless of whether patients have pre-operative pulmonary hypertension.

A novel calcium scoring system accurately predicts likelihood and location of post-TAVI paravalvular leak.

AIM: Sclerosis distribution, topography and morphology in aortic stenosis may have an impact on the localisation of post-procedural paravalvular leakage (PVL) following transcatheter aortic valve implantation (TAVI). METHODS: Between 05/2005 and 03/2011 a total of 208 patients underwent either transapical (TA) or transvascular (TV) TAVI using the Edwards-SAPIEN(TM), or CoreValve(TM) system. Aortic cusp and annular sclerosis distribution and aortic valve sclerosis symmetry were evaluated by preoperative transesophageal echocardiography (TOE). Mild, moderate and severe PVL after TAVI (group 1, N.=117) were analysed and compared to those patients with no signs of postprocedural PVL (group 2, N.=91). Commercial available image processing and analysing software were used to evaluate all relevant calcific sections (aortic sclerosis score 0-66; symmetry score 0-5) and were matched with the localization of the PVLs. RESULTS: A total of 117 patients (83±6 years, mean logistic EuroSCORE 20.1±12.7%) were identified with a mild-moderate PVL (TV, N.=102; TA, N.=15). Mean aortic sclerosis score was 38.7±7.6 in group 1 compared to 33.7±8.3 in group 2 (P<0.001) showing highest calcification in the non-coronary part for both groups. The mean symmetry score was 1.9±1.0 group 1 compared to 1.7±1.0 in group 2 (P=0.12). Regression analysis showed a significant relation of preoperative cusp localisation to the corresponding paravalvular leakage (P<0.001). CONCLUSION: The present study shows that a aortic sclerosis score constructed by TOE enables prediction of postoperative PVL and moreover, the localisation of PVL after TAVI correlates with the corresponding preoperative amount of sclerosis for each cusp.

Arrhythmogenic risk of pulmonary artery catheterisation in patients with severe aortic stenosis undergoing transcatheter aortic valve implantation.

Many clinicians consider severe aortic stenosis to be a contraindication to pulmonary artery catheterisation, except during open heart surgery with cardiopulmonary bypass. This is due to the perceived high risk of arrhythmia, although the true incidence of ventricular tachycardia and fibrillation remains unclear. We conducted a retrospective study to estimate the incidence of severe arrhythmias during pulmonary artery catheterisation in 380 patients with severe aortic stenosis scheduled for transcatheter aortic valve implantation. Ventricular fibrillation was seen in only one patient (0.26%), and this was successfully terminated by external defibrillation. No episodes of ventricular tachycardia were recorded and there were also no arrhythmias during removal of the catheter. We have therefore concluded that pulmonary artery catheterisation in patients with severe aortic stenosis is not associated with a high incidence of ventricular fibrillation or tachycardia, allowing pulmonary artery pressure monitoring to be performed relatively safely in such patients.

Compassionate use of the self-expandable medtronic CoreValve prosthesis for the treatment of pure aortic regurgitation in a patient at prohibitive risk for surgical valve replacement.

Transcatheter aortic valve implantation (TAVI) is a viable treatment option for high- and prohibitive-risk patients with severe, calcified pure or predominant aortic valve stenosis, but not for pure aortic valve regurgitation. In fact, the use of TAVI for this indication is even considered unlikely due to the lack of calcium which appears essential for anchoring the stent-valve and prevents dislocation. We report a case of a patient with severe, symptomatic pure aortic regurgitation, and a history of two previous open-heart surgeries who was successfully treated by compassionate use implantation of an oversized Medtronic CoreValve prosthesis as an ultima ratio treatment option.

[Renal denervation: current state and future perspectives]. / Renale Denervierung: Atueller Stand und Perspektiven.

Hypertension is a well-known risk factor for major cardiovascular events. Despite advances in medical therapy, sufficient treatment of hypertension remains unsatisfying in a substantial number of patients and is therefore one of the main challenges in modern medicine. In Germany 5-15 % of patients with hypertension suffer from resistant hypertension with elevated blood pressure despite the use of at least three antihypertensive drugs. Additionally patients often suffer from side effects. In patients with resistant hypertension the important role of the sympathetic nervous system with increased sympathetic activity is well known. In the past surgical sympathectomy with extended removal of sympathetic ganglia was performed to reduce blood pressure in patients with malignant hypertension. The positive effect of this highly invasive procedure on blood pressure led to the development of new strategies for the treatment of uncontrolled hypertension. One of the novel procedures includes catheter-based renal sympathetic denervation. The most common system is the radiofrequency ablation catheter (Symplicity®, Medtronic, Minneapolis, USA) which ablates the nerve fibers in the adventitia of the renal arteries by using high-frequency energy. As the results of the Symplicity trials (HTN-1 and HTN-2) showed significant reduction of systolic and diastolic blood pressure after renal denervation there is growing interest in this novel procedure. Moreover, by reducing the sympathetic activity after renal denervation early results indicate a positive impact on glucose metabolism, sleep apnea syndrome, as well as heart and renal failure. These effects led to the development of many different devices for renal denervation; however, trials with a higher number of patients and longer follow-up need to confirm these initially promising results and the value of newer devices. Until then renal denervation should not be regarded as standard therapy for arterial hypertension or an alternative to medical antihypertensive treatment and should be reserved for selected patients with resistant hypertension and specialized medical centres.

[Interventional left atrial appendage occlusion. A reasonable alternative to oral anticoagulation - even in the era of the new substances?]. / Interventioneller Vorhofohrverschluss. Alternative zur oralen Antikoagulation - auch im Zeitalter der neuen Substanzen?

As a potential alternative to long-term oral anticoagulation with vitamin K antagonists in patients with atrial fibrillation, the interventional left atrial appendage occlusion has shown to be non-inferior regarding neurological events. With the new oral direct factor II and factor Xa inhibitors playing an emerging role in stroke prophylaxis, an individual treatment strategy has to be found weighing bleeding and stroke risk against the peri-interventional complication rate based on established risk scores.

Current developments in transcatheter aortic valve implantation techniques.

Transcatheter aortic valve implantation (TAVI) has become a viable treatment option in high-risk patients with symptomatic aortic stenosis. The widespread uses of TAVI procedures in recent years and the steadily growing evolution of numerous new catheter-based devices have led to a remarkable shift in the treatment of this patients group towards TAVI procedures. Several developments have now overcome most of the initial problems with the early devices and have been quickly implemented in clinical routine. Nevertheless, several current TAVI systems have shown a number of limitations and disadvantages relating to valve design, the occurrence of paravalvular leakages, valve positioning and deployment, the occurrence of thromboembolic events during the procedure, as well as vascular or conduction complications. As a result, all current efforts in further development focus primarily on the following issues: (1) the further miniaturization of catheter devices and sheaths not only to facilitate transarterial but also transapical access; (2) the development of a broad variety of valve sizes to cover all aortic annulus sizes; (3) the development of retrievable, repositionable and removable systems; (4) the development or modification of stent design to prevent or reduce paravalvular leakages; (5) the implementation of modern imaging and navigation tools; (6) and finally, the initial development of prophylactic devices to prevent thromboembolic events. The present article provides a review of current developments in the field of TAVI.

Transfemoral aortic valve implantation under sedation and monitored anaesthetic care--a feasibility study.

Surgical aortic valve replacement is the conventional treatment for symptomatic aortic valve stenosis; however, the technique of transfemoral transcatheter aortic valve implantation has recently been developed for older patients at high risk for surgery. We assessed whether this procedure could be safely performed under sedation in 100 patients. Their predicted surgical mortality was 21.6% and mean (SD) age 80 (6.6) years. Sedation was provided by remifentanil infusion (0-0.2 µg.kg(-1).min(-1)) and midazolam (1-3 mg), as required. All patients were closely haemodynamically monitored throughout by an anaesthetist and inotropic drugs administered as indicated by invasive monitoring. Sedation alone was required in 83 patients; in 17 patients sedation had to be converted to general anaesthesia, mainly because of interventional complications (n = 12). All conversions to general anaesthesia occurred after successful valve implantation. Mean (SD) anaesthesia time was 31 (12) min and procedural time 107 (77) min; 30-day and 1-year all-cause mortality were 6% and 13%, respectively. In the majority of patients, transcatheter valve implantation can safely be facilitated by sedation, provided monitoring and drug administration are carried out by an experienced cardiac anaesthetist.

Transcatheter aortic valve implantation: evidence on safety and efficacy compared with medical therapy. A systematic review of current literature.

OBJECTIVES: Transcatheter aortic valve implantation (TAVI) promises effective treatment for high-risk elderly patients with symptomatic severe aortic stenosis (AS). However, the adoption of TAVI must be justified and guarantee long-term performance. Systematic reviews are a core methodology in evidence-based health economics for judging medical effectiveness. In this work, the methodology was applied to provide objective evidence on the efficacy and safety of TAVI at 1-year follow-up and to assess whether TAVI confers a survival benefit compared with medical therapy. METHODS: In accordance with the toolkit of the "German Scientific Working Group Technology Assessment for Health Care" (GSWG), a systematic literature review on the safety and efficacy of TAVI procedures was conducted in major bibliographic databases to identify all relevant publications. Preestablished inclusion criteria were defined. An initial screening of identified articles regarding titles and abstracts was followed by a full-text screening. Data from eligible articles were extracted and evaluated according to GSWG checklists followed by a qualitative synthesis of information. RESULTS: The systematic literature search identified 12 primary publications (derived from 1,849 citations) for TAVI [number of patients (n) = 1,049] and 11 publications (derived from 189 citations) for medical therapy of AS (n = 946) that fulfilled the inclusion criteria. Mean overall procedural success rate for included TAVI interventions was 93.3%. Mean combined procedural, post-procedural, and cumulative in-hospital/30-day mortality was 11.4% (n = 116; range 5.3-23%). 1 year after TAVI, the mean overall survival rate was 75.9% (range 64.1-87%) compared with 62.4% (range 40-84.8%) for medically treated patients (p value < 0.01). 1-year survival after TAVI for patients treated with transvascular (TV) procedures was higher than after transapical (TA) procedures (79.2 vs. 73.6%) (p value = 0.04). At 1-year follow-up, the improved valvular function remained stable, and there was a trend towards an improved ventricular function. CONCLUSION: Based on the best available data, in patients with symptomatic severe AS, TAVI demonstrates an improved 1-year survival compared with medical treatment. The survival benefit of TV-TAVI over medical therapy elucidated from this systematic literature review is +16.8% and therefore, in good congruence with the recently published results from the randomized PARTNER US trial (+20%).

Intramural hematoma and penetrating ulcers: indications to endovascular treatment.

Intramural hematoma (IMH) of the aorta and penetrating aortic ulcer (PAU) are important variant forms of classic double-barrel aortic dissection in patients presenting with acute aortic syndrome. Recent insights provided by modern high-resolution imaging are currently challenging previous pathophysiologic concepts underlying IMH and PAU, suggesting a close relationship of both entities. Thoracic endovascular aortic repair (TEVAR) offers a less invasive approach to the treatment of affected patients with very encouraging early to midterm results. This review discusses current indication for TEVAR in IMH and PAU patients in the view of an improved understanding of these diseases.

Negative inotropic effect of rapamycin on isolated human cardiomyocytes.

Rapamycin is an increasingly important immunosuppressive drug and reduces restenosis after coronary stenting, but its effects on cardiac contractility are largely unknown. We investigated the acute inotropic effects of rapamycin on isolated human cardiomyocytes. Cardiomyocytes were enzymatically isolated from right atrial appendages obtained during routine coronary artery bypass surgery. Cell morphology was examined by confocal microscopy. Cell contraction was recorded after electrical stimulation. Rapamycin elicited a concentration-dependent decrease in fractional cell shortening ranging from 14.3 +/- 2.6% at 10(-8) M rapamycin to 26.4 +/- 4.2% at 10(-5) M. Rapamycin also caused a concentration-dependent decrease in diastolic cell length. Contractile performance of isolated cardiomyocytes was well preserved, as evidenced by the profound positive inotropic effects of high extracellular calcium concentration and the beta-adrenoreceptor agonist isoproterenol. The acute negative inotropic effect of rapamycin on human cardiomyocytes might be due to altered calcium homeostasis through the binding of rapamycin to FKBP12.6 and its regulatory function on the ryanodine receptor, with increased calcium leakage from the sarcoplasmic reticulum.

Effect of gender and highly active antiretroviral therapy on HIV-related pulmonary arterial hypertension: results of the HIV-HEART Study.

BACKGROUND: Idiopathic pulmonary arterial hypertension (PAH) is a rare disease. HIV-infected patients exhibit a considerably higher rate of development of this condition compared to the general population. METHODS: This cross-sectional study of 802 (83.4% male; age 44.3+/-10.3 years) HIV-positive patients aimed to evaluate the male-to-female ratio in HIV-related PAH and to elucidate whether PAH is more likely to occur in patients receiving highly active antiretroviral therapy (HAART) than in HIV-treatment-naïve patients. All patients were examined by Doppler echocardiography to estimate systolic pulmonary arterial pressure (sPAP). Manifest PAH was defined as sPAP >35 mmHg at rest in combination with symptoms of dyspnoea. RESULTS: A total of 38 (4.7%) patients were diagnosed with elevated sPAP >35 mmHg. Fourteen (1.7%; 11 male) of these patients presented with symptoms of dyspnoea, resulting in a male-to-female ratio of manifest HIV-associated PAH of 1:1.4. Patients with symptoms of dyspnoea and sPAP>35 mmHg were more likely to receive HAART (13/14 patients). CONCLUSIONS: In HIV patients, sPAP occurs more frequently than has been reported previously; the condition is possibly associated with HAART. Furthermore, HIV-positive females exhibit a higher prevalence of HIV-related PAH (HIV-PAH) than HIV-positive males.

Gadolinium-based coronary angiography in patients with contraindication for iodinated x-ray contrast medium: a word of caution.

BACKGROUND: In coronary angiography, the use of contrast agents containing iodine still defines the gold standard. In patients with contraindications for iodine exposition, gadolinium has been considered to be a safe alternative to standard iodinated contrast medium for coronary angiography. The aim of the present study was to assess the safety and technical quality of gadolinium-based coronary angiography. METHODS: Nineteen consecutive patients with contraindication to iodinated contrast medium underwent gadolinium-based coronary angiography. Contraindications included previous anaphylactic shock or severe allergic reaction to iodinated contrast medium (n = 13) or thyrotoxicosis (n = 6). Gadolinium was diluted 1:1 with sodium chloride before application. Patients were clinically observed for potential side effects, and renal function was assessed by determination of creatinine values and calculation of creatinine clearance in pre- and postprocedural blood samples. Image quality was evaluated by two independent observers, and classified into three different categories (grade 1, high diagnostic quality; grade 2, moderate diagnostic quality; and grade 3, poor quality). RESULTS: During angiography, a mean of 32.6 +/- 10.9 mL (range 10-45 mL) gadolinium was used. No patient developed a significant impairment of renal function within 24 hours after the examination (mean creatinine value preprocedural: 1.12 +/- 0.15 mg/dL, postprocedural: 6 hours 1.15 +/- 0.18 mg/dL, 24 hours 1.13 +/- 0.16 mg/dL) (baseline vs. 6 hours P = 0.23, baseline vs. 24 hours P = 0.66, 6 hours vs. 24 hours P = 0.12) (mean creatinine clearance preprocedural: 73.8 +/- 18 mg/dL, postprocedural: 6 hours 71.7 +/- 16.8 mg/dL, 24 hours 73.2 +/- 17.8 mg/dL) (baseline vs. 6 hours P = 0.2, baseline vs. 24 hours P = 0.71, 6 hours vs. 24 hours P = 0.21). Four patients (21%) suffered severe complications due to gadolinium application, such as malignant cardiac arrhythmias (n = 3) and hemodynamic decompensation (n = 1). Image quality was generally reduced in comparison to iodine contrast coronary angiography, but was adequate for diagnostic purposes (13 patients [68.4%] had reasonably good picture contrast [grade 2.1 +/- 0.3]; in 6 patients [31.6%], image quality was satisfactory [grade 2.6 +/- 0.13]). Opacification of distal vessels as compared to proximal segments was remarkably reduced. CONCLUSIONS: Gadolinium-based coronary angiography is a potential alternative technique in patients with allergy to iodinated contrast medium or thyrotoxicosis with reduced, but acceptable, image quality for diagnostic purposes. Nevertheless, possible life-threatening side effects and complications have to be considered.