Tim Süselbeck

Incidence and severity of coronary artery disease in patients with atrial fibrillation undergoing first-time coronary angiography.

Background In standard reference sources, the incidence of coronary artery disease (CAD) in patients with atrial fibrillation (AF) ranged between 24 and 46.5%. Since then, the incidence of cardiovascular risk factors (CRF) has increased and modern treatment strategies (“pill in the pocket”) are only applicable to patients without structural heart disease. The aim of this study was to investigate the incidence and severity of CAD in patients with AF. Methods From January 2005 until December 2009, we included 261 consecutive patients admitted to hospital with paroxysmal, persistent or permanent AF in this prospective study. All patients underwent coronary angiography and the Framingham risk score (FRS) was calculated. Patients with previously diagnosed or previously excluded CAD were excluded. Results The overall incidence of CAD in patients presenting with AF was 34%; in patients >70 years, the incidence of CAD was 41%. The incidence of patients undergoing a percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) was 21%. Patients with CAD were older (73±8 years vs 68±10 years, p = 0.001), had significantly more frequent hypercholesterolemia (60% vs 30%, p<0.001), were more frequent smokers (26% vs 13%, p = 0.017) and suffered from angina more often (37% vs 2%, p<0.001). There was a significant linear trend among the FRS categories in percentage and the prevalence of CAD and PCI/CABG (p<0.0001). Conclusions The overall incidence of CAD in patients presenting with AF was relatively high at 34%; the incidence of PCI/CABG was 21%. Based upon increasing CRF in the western world, we recommend a careful investigation respecting the FRS to either definitely exclude or establish an early diagnosis of CAD – which could contribute to an early and safe therapeutic strategy considering type Ic antiarrhythmics and oral anticoagulation.

In vivo intravascular electric impedance spectroscopy using a new catheter with integrated microelectrodes.

Abstract Interventional techniques are necessary, which allow the characterization of intravascular pathological processes. Electric impedance spectroscopy (EIS) can provide cellular information of biological tissue. We tested the feasibility of intravascular EIS by using a new impedance catheter system with integrated microelectrodes in an experimental animal model. Eighteen stents were implanted into the iliac arteries of female New Zealand White rabbits (n = 11) to induce intimal proliferation. After 14, 28 and 56 days the electric impedance was measured inside and outside of the stented arterial segments by using a balloon catheter with four integrated microelectrodes. The impedance was recorded at a frequency ranging from 1 Hz to 1 MHz. After the measurements, the stents were explanted and histomorphometry was performed. The impedance inside and outside the stent was analysed and compared with the histomorphometric data.Fourteen (n = 6), 28 (n = 5) and 56 (n = 6) days after stent implantation the difference of the electrical impedance between the native and the stented iliac artery segment increased from –924 ± 715 Ohm to 3689 ± 1385 Ohm (14 days vs. 28 days; p < 0.05) and 8637 ± 2881 Ohm (14 days vs. 56 days; p < 0.05), respectively. The increase of the electrical impedance corresponded to an increased neointimal proliferation in the stented arterial segment of 3.6% ± 0.7% after 14 days, 8.4% ± 4.8% after 28 days (14 days vs. 28 days; p < 0.05) and 10.0% ± 4.1% after 56 days (14 days vs. 56 days; p < 0.01).Intravascular EIS can be performed by a balloon catheter with integrated microelectrodes and allows the detection of neointimal proliferation after stent implantation.

Intravascular electric impedance spectroscopy of atherosclerotic lesions using a new impedance catheter system

Newer techniques are required to identify atherosclerotic lesions that are prone to rupture. Electric impedance spectroscopy (EIS) can characterize biological tissues by measuring the electrical impedance over a frequency range. We tested a newly designed intravascular impedance catheter (IC) by measuring the impedance of different stages of atherosclerosis induced in an animal rabbit model. Six female New Zealand White rabbits were fed for 17 weeks with a 5% cholesterol–enriched diet to induce early forms of atherosclerotic plaques. All aortas were prepared from the aortic arch to the renal arteries and segments of 5–10 mm were marked by ink spots. A balloon catheter system with an integrated polyimide–based microelectrode structure was introduced into the aorta and the impedance was measured at each spot by using an impedance analyzer. The impedance was measured at frequencies of 1 kHz and 10 kHz and compared with the corresponding histomorphometric data of each aortic segment.Forty–four aortic segments without plaques and 48 segments with evolving atherosclerotic lesions could be exactly matched by the histomorphometric analysis. In normal aortic segments (P0) the change of the magnitude of impedance at 1 kHz and at 10 kHz (|Z|1 kHz – |Z|10 kHz, = ICF) was 208.5 ± 357.6 Ω. In the area of aortic segments with a plaque smaller than that of the aortic wall diameter (PI), the ICF was 137.7 ± 192.8 Ω. (P 0 vs. P I; p = 0.52), whereas in aortic segments with plaque formations larger than the aortic wall (PII) the ICF was significantly lower –22.2 ± 259.9 Ω. (P0 vs. PII; p = 0.002). Intravascular EIS could be successfully performed by using a newly designed microelectrode integrated onto a conventional coronary balloon catheter. In this experimental animal model atherosclerotic aortic lesions showed significantly higher ICF in comparison to the normal aortic tissue.

Intracoronary Delivery of Injectable Bioabsorbable Scaffold (IK-5001) to Treat Left Ventricular Remodeling After ST-Elevation Myocardial Infarction A First-in-Man Study

Background—We aimed to test, for the first time, the feasibility of intracoronary delivery of an innovative, injectable bioabsorbable scaffold (IK-5001), to prevent or reverse adverse left ventricular remodeling and dysfunction in patients after ST-segment–elevation myocardial infarction. Methods and Results—Patients (n=27) with moderate-to-large ST-segment–elevation myocardial infarctions, after successful revascularization, were enrolled. Two milliliters of IK-5001, a solution of 1% sodium alginate plus 0.3% calcium gluconate, was administered by selective injection through the infarct-related coronary artery within 7 days after myocardial infarction. IK-5001 is assumed to permeate the infarcted tissue, cross-linking into a hydrogel and forming a bioabsorbable cardiac scaffold. Coronary angiography, 3 minutes after injection, confirmed that the injection did not impair coronary flow and myocardial perfusion. Furthermore, IK-5001 deployment was not associated with additional myocardial injury or re-elevation of cardiac biomarkers. Clinical assessments, echocardiographic studies, 12-lead electrocardiograms, 24-hour Holter monitoring, blood tests, and completion of Minnesota Living with Heart Failure Questionnaires were repeated during follow-up visits at 30, 90, and 180 days after treatment. During a 6-month follow-up, these tests confirmed favorable tolerability of the procedure, without device-related adverse events, serious arrhythmias, blood test abnormalities, or death. Serial echocardiographic studies showed preservation of left ventricular indices and left ventricular ejection fraction. Conclusions—This first-in-man pilot study shows that intracoronary deployment of an IK-5001 scaffold is feasible and well tolerated. Our results have promoted the initiation of a multicenter, randomized controlled trial to confirm the safety and efficacy of this new approach in high-risk patients after ST-segment–elevation myocardial infarction. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01226563.

Role of vessel size as a predictor for the occurrence of in-stent restenosis in patients with diabetes mellitus

Intracoronary stents have been shown to reduce the rate of restenosis when compared with balloon angioplasty, but in-stent restenosis continues to be an important clinical problem. It was therefore the aim of this registry to identify procedural and angiographic predictors for the occurrence of in-stent restenosis. We analyzed 368 patients with 421 lesions who underwent coronary stent implantation between January 1998 and February 2000. Indications for the placement of a coronary stent were severe dissections (37%), suboptimal angiographic results (38%), restenotic lesions (20%), and graft lesions (4%). Angiographic follow-up was obtained in 270 patients (73%) with 293 lesions after 6 months. Clinical and angiographic variables were analyzed by univariate and multivariate models for the ability to predict the occurrence of in-stent restenosis, defined as a diameter stenosis >50%. In-stent restenosis was angiographically documented in 67 patients and 68 lesions (23%). Under all tested variables the reference luminal diameter before stent implantation (p = 0.006) and diabetes mellitus (p = 0.023) were identified as independent predictors for the occurrence of in-stent restenosis. The comparison of diabetic and nondiabetic patients according to vessel size revealed a 2 times higher rate of in-stent restenosis in small vessels (44% vs 23%, p = 0.002), whereas in vessels >3.0 mm the rate of in-stent restenosis was not significantly different between the 2 groups. In this registry, the clinical variable diabetes and the procedural variable reference vessel size were independent predictors for the occurrence of in-stent restenosis. In these patients, the rate of in-stent restenosis was as high as 45%.

Takotsubo cardiomyopathy is not due to plaque rupture: an intravascular ultrasound study.

Plaque rupture with subsequent transient thrombotic coronary occlusion by a fast‐dissolving clot is one of the proposed pathogenic mechanisms in Takotsubo cardiomyopathy (TC).

Takotsubo Cardiomyopathy (Acute Left Ventricular Apical Ballooning Syndrome) Occurring in the Intensive Care Unit

ObjectiveDiagnosis of Takotsubo cardiomyopathy (also known as stress cardiomyopathy or acute left ventricular apical ballooning syndrome) can be challenging in patients who are being treated for other diseases in the intensive care unit, because symptoms could erroneously be attributed to the underlying disease or patients may not experience symptoms due to analgesia and sedation. The aim of our study was to assess clinical features of Takotsubo cardiomyopathy occurring in the intensive care unit.DesignProspective observational study.SettingUniversity hospital.PatientsSix consecutive patients diagnosed with Takotsubo cardiomyopathy who were being treated for other diseases in the intensive care unit.InterventionsNone.Measurements and main resultsSudden hemodynamic deterioration (i.e., sudden hypotension, tachycardia or drop in monitored stroke volume) requiring vasopressor support was the presenting symptom in five of the six patients. Only one patient was able to report angina-like chest pain, all others were unable to experience symptoms due to analgesia and sedation. The electrocardiogram was abnormal in all patients upon diagnosis, demonstrating either ST-segment elevation (n = 2) and/or T-wave inversion (n = 5). Mild elevation of cardiac enzymes disproportionate to the extent of wall motion abnormalities on left ventriculography was present in all patients. All patients survived their acute event.ConclusionsSudden hemodynamic deterioration requiring vasopressor support and/or ECG abnormalities consisting of ST-segment elevation, ST-segment depression or T-wave inversion may be the presenting symptom of Takotsubo cardiomyopathy in the intensive care unit and should be included in the diagnostic algorithm.

Global and regional myocardial function quantification by two-dimensional strain in Takotsubo cardiomyopathy

AIMS This study sought to characterize global and regional systolic function in Takotsubo cardiomyopathy (TC) using two-dimensional (2D) strain imaging. METHODS AND RESULTS Twelve consecutive patients (11 women, 1 man) underwent 2D echocardiography on admission and on early follow-up (34 +/- 16 days). Two-dimensional images were analysed to measure longitudinal and radial strain and to calculate post-systolic shortening (PSS) and the post-systolic index (PSI). Mean age was 64 +/- 14 years. Upon presentation ejection fraction, average longitudinal and radial strains were 42 +/- 9%, -10.6 +/- 5.5%, and 20.1 +/- 17.3%, respectively. Values improved to 59 +/- 8%, -17.6 +/- 3.0%, and 50.2 +/- 17.0%, respectively (all P < 0.001). PSS was present in 69% of segments upon presentation and in 53% of segments upon follow-up. PSI was -0.16 at baseline and improved to -0.06 upon follow-up (P < 0.001). CONCLUSION Patients with TC show abnormal global and regional strain patterns during the acute phase of the disease which improve over time. However, subtle abnormalities of regional LV function seem to persist into the early follow-up period as suggested by the presence of PSS in more than half of LV segments. Long-term follow-up studies are needed to clarify whether these subtle abnormalities will further improve.

Long-Term Results of Transapical Versus Transfemoral TAVI in a Real World Population of 1000 Patients With Severe Symptomatic Aortic Stenosis

Background—Transapical transcatheter aortic valve implantation is generally perceived to be associated with increased morbidity compared with transfemoral transcatheter aortic valve implantation. We aimed to compare access-related complications and survival using propensity score matching. Methods and Results—Prospective, single-center registry of 1000 consecutive patients undergoing transapical and transfemoral transcatheter aortic valve implantation between May 2008 and April 2012. Transapical was performed in 413 patients and transfemoral in 587 patients. Patients with transapical access were less often women and less had pulmonary hypertension. Further they had more peripheral arterial disease, coronary artery disease, carotid stenosis, and recurrent surgery and a higher logistic EuroSCORE I (24.3%±16.2% for transapical versus 22.2%±16.2% for transfemoral; P<0.01). After building 2 propensity score–matched groups of 354 patients each with either access route (total 708 patients), baseline characteristics were comparable. In this analysis, there was no significant difference in 30 day mortality (5.9% transapical versus 8.5% transfemoral; P=0.19), the rate of myocardial infarction (2.5% transapical versus 2.0% transfemoral; P=0.61), stroke (2.0% transapical versus 2.3% transfemoral; P=0.79), bleeding complications, pacemaker implantation rates, or moderate aortic insufficiency. Stage 1 renal complications were more common in transapical patients (odds ratio, 2.81; 95% confidence interval, 1.93–4.09), whereas major vascular complications were less common (odds ratio, 0.14; 95% confidence interval, 0.06–0.29). Survival probability over the long term was not statistically different (hazard ratio, 0.89; 95% confidence interval, 0.72–1.10; log-rank Test, P=0.27). Conclusions—The data demonstrate that in an experienced multidisciplinary heart team, either access route can be performed with comparable results.

CMR findings in patients with hypertrophic cardiomyopathy and atrial fibrillation

ObjectivesWe sought to evaluate the relation between atrial fibrillation (AF) and the extent of myocardial scarring together with left ventricular (LV) and atrial parameters assessed by late gadolinium-enhancement (LGE) cardiovascular magnetic resonance (CMR) in patients with hypertrophic cardiomyopathy (HCM).BackgroundAF is the most common arrhythmia in HCM. Myocardial scarring is also identified frequently in HCM. However, the impact of myocardial scarring assessed by LGE CMR on the presence of AF has not been evaluated yet.Methods87 HCM patients underwent LGE CMR, echocardiography and regular ECG recordings. LV function, volumes, myocardial thickness, left atrial (LA) volume and the extent of LGE, were assessed using CMR and correlated to AF. Additionally, the presence of diastolic dysfunction and mitral regurgitation were obtained by echocardiography and also correlated to AF.ResultsEpisodes of AF were documented in 37 patients (42%). Indexed LV volumes and mass were comparable between HCM patients with and without AF. However, indexed LA volume was significantly higher in HCM patients with AF than in HCM patients without AF (68 ± 24 ml·m-2 versus 46 ± 18 ml·m-2, p = 0.0002, respectively). The mean extent of LGE was higher in HCM patients with AF than those without AF (12.4 ± 14.5% versus 6.0 ± 8.6%, p = 0.02). When adjusting for age, gender and LV mass, LGE and indexed LA volume significantly correlated to AF (r = 0.34, p = 0.02 and r = 0.42, p < 0.001 respectively). By echocardiographic examination, LV diastolic dysfunction was evident in 35 (40%) patients. Mitral regurgitation greater than II was observed in 12 patients (14%). Multivariate analysis demonstrated that LA volume and presence of diastolic dysfunction were the only independent determinant of AF in HCM patients (p = 0.006, p = 0.01 respectively). Receiver operating characteristic curve analysis indicated good predictive performance of LA volume and LGE (AUC = 0.74 and 0.64 respectively) with respect to AF.ConclusionHCM patients with AF display significantly more LGE than HCM patients without AF. However, the extent of LGE is inferior to the LA size for predicting AF prevalence. LA dilation is the strongest determinant of AF in HCM patients, and is related to the extent of LGE in the LV, irrespective of LV mass.