Andreas Wahl - Academia.edu (original) (raw)

Papers by Andreas Wahl

High dose dobutamine magnetic resonance stress testing has been shown to be superior to dobutamin... more High dose dobutamine magnetic resonance stress testing has been shown to be superior to dobutamine stress echocardiography for the diagnosis of coronary artery disease (CAD). We determined the feasibility of quantitative myocardial tagging during low and high dose dobutamine stress and tested the ability of global systolic and diastolic quantitative parameters to identify patients with significant CAD.

The American journal of cardiology, Jan 15, 2015

The aim of our study was to evaluate 3-dimensional (3D) color Doppler proximal isovelocity surfac... more The aim of our study was to evaluate 3-dimensional (3D) color Doppler proximal isovelocity surface area (PISA) as a tool for quantitative assessment of mitral regurgitation (MR) against in vitro and in vivo reference methods. A customized 3D PISA software was validated in vitro against a flowmeter MR phantom. Sixty consecutive patients, with ≥mild MR of any cause, were recruited and the regurgitant volume (RVol) was measured by 2D PISA, 3D peak PISA, and 3D integrated PISA, using transthoracic (TTE) and transesophageal echocardiography (TEE). Cardiac magnetic resonance imaging (CMR) was used as reference method. Flowmeter RVol was associated with 3D integrated PISA as follows: y = 0.64x + 4.7, r(2) = 0.97, p <0.0001 for TEE and y = 0.88x + 4.07, r(2) = 0.96, p <0.0001 for TTE. The bias and limit of agreement in the Bland-Altman analysis were 6.8 ml [-3.5 to 17.1] for TEE and -0.059 ml [-6.2 to 6.1] for TTE. In vivo, TEE-derived 3D integrated PISA was the most accurate method f...

JACC. Cardiovascular interventions, 2009

We sought to assess the safety and clinical efficacy of patent foramen ovale (PFO) closure under ... more We sought to assess the safety and clinical efficacy of patent foramen ovale (PFO) closure under fluoroscopic guidance only, without intraprocedural echocardiography. Percutaneous PFO closure has been shown to be safe and feasible using several devices. It is generally performed using simultaneously fluoroscopic and transesophageal or intracardiac echocardiographic guidance. Transesophageal echocardiography requires sedation or general anesthesia and intubation to avoid aspiration. Intracardiac echocardiography is costly and has inherent risks. Both lengthen the procedure. The Amplatzer PFO Occluder (AGA Medical Corporation, Golden Valley, Minnesota) can be safely implanted without echocardiographic guidance. A total of 620 patients (51 +/- 12 years; 66% male) underwent PFO closure using the Amplatzer PFO Occluder for secondary prevention of presumed paradoxical embolism. Based on size and mobility of the PFO and the interatrial septum, an 18-mm device was used in 50 patients, a 25-...

Journal of Neurology Neurosurgery and Psychiatry, 2002

Objectives. The aim was to estimate the recurrence rate and to define subgroups at increased risk... more Objectives. The aim was to estimate the recurrence rate and to define subgroups at increased risk for recurrent cerebral ischaemia in patients with patent foramen ovale (PFO) and so called cryptogenic stroke due to paradoxical embolism.Methods. Patent foramen ovale was diagnosed in 318 patients with otherwise unexplained ischaemic stroke or transient ischaemic attack (TIA). One hundred and fifty nine were

Background. Patients with transient ischemic attack (TIA) and stroke related to patent foremen ov... more Background. Patients with transient ischemic attack (TIA) and stroke related to patent foremen ovale (PFO) are at risk for recurrence. The best treatment for secondary prevention is not known. The purpose of this study was to compare the risk of recurrence between medical treatment and percutaneous PFO closure in patients with TIA and stroke related to PFO. Methods. A total of 311 patients with TIA or stroke related to PFO were retrospectively included in a case-control study. 161 patients received medical treatment (oral anticoagulation: n=80, platelet inhibitors: n=81), and 150 patients underwent percutaneous PFO closure. The actuarial risk of recurrence was calculated and compared between the two groups. Results. The mean age of the study population was 50=13 years. The two groups were matched for age, sex and presence of an associated atnal septal aneurysm. The overall mean follow-up was 2.3¢1.8 years, 2.4±1.9 years in the medical treatment group and 2.2¢1.5 years in the percutaneous PFO closure group. The average annual TIA and/or stroke rate was 6.6% in the medical and 4.5% in the endovascular group (p=0.08). There were no recurrent major strokes in the percutaneous PFO closure group compared with 7 recurrent events in the medically treated patients (p=0.02). Patients with 2 or more events before enrolment were at higher risk for recurrence when treated medically (11% per year) compared to percutaneous PFO closure (5% per year; p=0.01). Multivariate logistic regression analysis identified arterial hypertension, and more than one ambolic event at baseline as significant predictors for recurrence (OR 2.2, 95% CI 1.1-4.9). Conclusions. Our results indicate a non-significant trend towards decreased recurrence for the combined endpoint of TIA and stroke, and a significant decrease in recurrent major strokes in patients with PFO and presumed paradoxical embolism undergoing percutaneous PFO closure compared with medical treatment. The subgroup of patients with 2 or more events before enrolment had a significantly lower recurrence rate after percutaneous PFO closure compared with medical treatment. Confirmation of these results by a prospective randomized trial with longer follow-up is needed.

Journal of The American College of Cardiology, 2003

A total of 42 subjects, including 6 volunteers and 34 patients suspected of coronary artery disea... more A total of 42 subjects, including 6 volunteers and 34 patients suspected of coronary artery disease (CAD), were recruited prospectively to measure scan time, breathhold frequency, anatomic coverage, image quality, and detection of CAD. The anatomic coverage was based on the number of coronary segments visualized using the 9 coronary segment model. Image quality of each coronary segment (gradel-4: l=excellent; P=good. 3=fair, and 4=nowdiagnostic) was assessed based on both vessel border contiguity and artifact. Three investigators blindly reviewed the MR images for CAD. Their findings were compared to the coronary angiograms reviewed by interventional cardiologists. Using a modern PC (AMD) as a sequencer, the aRT generated an arbitrary waveform to switch from real-time localization (RT) to cardiac gated high-resolution (HR)

The American Journal of Medicine, 2015

Background -To identify predisposing factors that can result in the onset of Takotsubo Syndrome, ... more Background -To identify predisposing factors that can result in the onset of Takotsubo Syndrome, we performed an international, collaborative systematic review focusing on clinical characteristics and comorbidities of patients with Takotsubo Syndrome.

Trials, 2011

Background: Several studies have shown an association of cryptogenic stroke and embolism with pat... more Background: Several studies have shown an association of cryptogenic stroke and embolism with patent foramen ovale (PFO), but the question how to prevent further events in such patients is unresolved. Options include antithrombotic treatment with warfarin or antiplatelet agents or surgical or endovascular closure of the PFO. The PC-Trial was set up to compare endovascular closure and best medical treatment for prevention of recurrent events. Methods: The PC-Trial is a randomized clinical trial comparing the efficacy of percutaneous closure of the PFO using the Amplatzer PFO occluder with best medical treatment in patients with cryptogenic embolism, i.e. mostly cryptogenic stroke. Warfarin for 6 months followed by antiplatelet agents is recommended as medical treatment. Randomization is stratified according to patients age (<45 versus ≥45 years), presence of atrial septal aneurysm (ASA yes or no) and number of embolic events before randomization (one versus more than one event). Primary endpoints are death, nonfatal stroke and peripheral embolism. Discussion: patients were randomized in 29 centers

Journal of the American College of Cardiology, 2005

This study sought to investigate the safety and efficacy of transcatheter treatment of atrial sep... more This study sought to investigate the safety and efficacy of transcatheter treatment of atrial septal aneurysm (ASA) associated with patent foramen ovale (PFO). BACKGROUND Patients with both ASA and PFO are at high risk for recurrent paradoxical embolism.

Journal of the American College of Cardiology, 2002

Journal of Magnetic Resonance Imaging, 2001

Contrast between blood and myocardium in standard turbo gradient echo MR techniques (TFE) used ro... more Contrast between blood and myocardium in standard turbo gradient echo MR techniques (TFE) used routinely in clinical practice is mainly caused by unsaturated inflowing blood. Steady-state free precession (SSFP) has excellent contrast even in the absence of inflow effects. In 45 subjects cardiac cine loops in two long axis projections were acquired using TFE and compared with SSFP. A visual score (range 0 worst - 3 best) was assigned for endocardial border delineation for six myocardial segments in two long axis views. Endocardial border delineation score for TFE was 1.3 +/- 0.3 per segment and 2.4 +/- 0.3 for SSFP (P < 0.0001). Signal intensity blood/signal intensity myocardium was 1.5 +/- 0.4 at enddiastole and 1.4 +/- 0.3 at systole for TFE and 3.5 +/- 1.1 and 3.2 +/- 1.3 for SSFP, respectively (P < 0.0001). SSFP increases contrast between blood and myocardium more than twofold, resulting in an improved endocardial border definition. This may reduce variability for the determination of cardiac volumes and ejection fraction.

International Journal of Cardiology, 2009

Background: Transient apical ballooning syndrome (TABS) or Takotsubo cardiomyopathy mimics acute ... more Background: Transient apical ballooning syndrome (TABS) or Takotsubo cardiomyopathy mimics acute ST-elevation myocardial infarction, but is considered to have a good prognosis with only moderate elevation of myocardial enzymes and full recovery of left ventricular function. Although it is increasingly reported, its exact incidence, clinical presentation, and prognosis in non-Asian populations remain largely unknown. Objective: To describe the clinical characteristics and long-term follow-up of patients who presented with TABS at our institution over a 3 year-period. Methods: Patients were retrospectively retrieved from our local database. Patient charts were carefully reviewed and the diagnosis of TABS was based on the Mayo Clinic diagnostic criteria. Moreover, psychosocial stress or gastrointestinal disease was recorded. Results: During the study period, 13,715 coronary angiographies were performed at our institution, including 2459 patients presenting with an acute coronary syndrome (ACS). Forty-one TABS were diagnosed, which represents an incidence of 1.7% of ACS-patients and 0.3% of all coronary angiographies performed, respectively. Mean age was 65 years, with 85% women. Clinical presentations included chest pain, dyspnoea, and cardiogenic shock. A preceding psychological or physical condition perceived as "stress" was reported in 61%. At a mean follow-up of 675 ± 288 days, none of the patients died of cardiac causes, but two patients had a recurrence of symptoms. Conclusions: This is the largest cohort of TABS patients reported out of Europe so far. The good overall prognosis and low likelihood of recurrence were confirmed.

Heart, 2008

To carry out long-term follow-up after percutaneous closure of patent foramen ovale (PFO) in pati... more To carry out long-term follow-up after percutaneous closure of patent foramen ovale (PFO) in patients with cryptogenic stroke. Prospective cohort study. Single tertiary care centre. 525 consecutive patients (mean (SD) age 51 (12) years; 56% male). Percutaneous PFO closure without intraprocedural echocardiography. Freedom from recurrent embolic events. A mean (SD) of 1.7 (1.0) clinically apparent embolic events occurred for each patient, and 186 patients (35%) had &amp;gt;1 event. An atrial septal aneurysm was associated with the PFO in 161 patients (31%). All patients were followed up prospectively for up to 11 years. The implantation procedure failed in two patients (0.4%). There were 13 procedural complications (2.5%) without any long-term sequelae. Contrast transoesophageal echocardiography at 6 months showed complete closure in 86% of patients, and a minimal, moderate or large residual shunt in 9%, 3% and 2%, respectively. Patients with small occluders (&amp;lt;30 mm; n = 429) had fewer residual shunts (small 11% vs large 27%; p&amp;lt;0.001). During a mean (SD) follow-up of 2.9 (2.2) years (median 2.3 years; total 1534 patient-years), six ischaemic strokes, nine transient ischaemic attacks (TIAs) and two peripheral emboli occurred. Freedom from recurrent stroke, TIA, or peripheral embolism was 98% at 1 year, 97% at 2 years and 96% at 5 and 10 years, respectively. A residual shunt (hazard ratio = 3.4; 95% CI 1.3 to 9.2) was a risk factor for recurrence. This study attests to the long-term safety and efficacy of percutaneous PFO closure guided by fluoroscopy only for secondary prevention of paradoxical embolism in a large cohort of consecutive patients.

European Journal of Cardio-Thoracic Surgery, 2010

Graft right ventricular (RV) function is compromised directly posttransplant, especially in heart... more Graft right ventricular (RV) function is compromised directly posttransplant, especially in heart transplantation (HTx) recipients with pretransplant pulmonary hypertension (PH). Graft RV size and systolic function, and the effect of the recipient&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s pulmonary haemodynamics on the graft extracellular matrix are not well characterised in the patients long-term after HTx. Comparison of RV size and systolic function in HTx recipients&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39; long-term posttransplant stratified by the presence of pretransplant PH. HTx survivors &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=2 years posttransplant were divided into group I without pretransplant PH (pulmonary vascular resistance, PVR &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;2.5 Wood units, n=37) and group II with PH (PVR &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=2.5 Wood units, n=16). RV size and systolic function were measured using cardiac magnetic resonance imaging (CMR). The collagen content was assessed in septal endomyocardial biopsies obtained at HTx and at study inclusion. Mean posttransplant follow-up was 5.2+/-2.9 years (group I) and 4.9+/-2.2 years (group II) (p=0.70). PVR was 1.5+/-0.6 vs 4.1+/-1.7 Wood units pretransplant (p&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.001), and 1.2+/-0.5 vs 1.3+/-0.5 Wood units at study inclusion (p=0.43). Allograft RV size and systolic function were similar in both groups (p always &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=0.07). Collagen content at transplantation and at follow-up were not different (p always &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;gt;or=0.60). Posttransplant normalisation of pretransplant PH is associated with normal graft RV function long-term after HTx.

Circulation, 2004

Background-Dobutamine stress MR (DSMR) is highly accurate for the detection of inducible wall mot... more Background-Dobutamine stress MR (DSMR) is highly accurate for the detection of inducible wall motion abnormalities (IWMAs). Adenosine has a more favorable safety profile and is well established for the assessment of myocardial perfusion. We evaluated the diagnostic value of IWMAs during dobutamine and adenosine stress MR and adenosine MR perfusion compared with invasive coronary angiography. Methods and Results-Seventy-nine consecutive patients (suspected or known coronary disease, no history of prior myocardial infarction) scheduled for cardiac catheterization underwent cardiac MR (1.5 T). After 4 minutes of adenosine infusion (140 g · kg Ϫ1 · min Ϫ1 for 6 minutes), wall motion was assessed (steady-state free precession), and subsequently perfusion scans (3-slice turbo field echo-echo planar imaging; 0.05 mmol/kg Gd-BOPTA) were performed. After a 15-minute break, rest perfusion was imaged, followed by standard DSMR/atropine stress MR. Wall motion was classified as pathological if Ն1 segment showed IWMAs. The transmural extent of inducible perfusion deficits (Ͻ25%, 25% to 50%, 51% to 75%, and Ͼ75%) was used to grade segmental perfusion. Quantitative coronary angiography was performed with significant stenosis defined as Ͼ50% diameter stenosis. Fifty-three patients (67%) had coronary artery stenoses Ͼ50%; sensitivity and specificity for detection by dobutamine and adenosine stress and adenosine perfusion were 89% and 80%, 40% and 96%, and 91% and 62%, respectively. Adenosine IWMAs were seen only in segments with Ͼ75% transmural perfusion deficit. Conclusions-DSMR is superior to adenosine stress for the induction of IWMAs in patients with significant coronary artery disease. Visual assessment of adenosine stress perfusion is sensitive with a low specificity, whereas adenosine stress MR wall motion is highly specific because it identifies only patients with high-grade perfusion deficits. Thus, DSMR is the method of choice for current state-of-the-art treatment regimens to detect ischemia in patients with suspected or known coronary artery disease but no history of prior myocardial infarction. (Circulation. 2004;110:835-842.)