Floris Kauer

Angiographic and Optical Coherence Tomography Insights Into Bioresorbable Scaffold Thrombosis Single-Center Experience

Background—As bioresorbable vascular scaffolds (BVSs) are being increasingly used in complex real-world lesions and populations, BVS thrombosis cases have been reported. We present angiographic and optical coherence tomography (OCT) findings in a series of patients treated in our center for definite bioresorbable scaffold thrombosis. Methods and Results—Up to June 2014, 14 patients presented with definite BVS thrombosis in our center. OCT was performed in 9 patients at the operator’s discretion. Angiographic and OCT findings were compared with a control group comprising 15 patients with definite metallic stent thrombosis. In the BVS group, time interval from index procedure to scaffold thrombosis ranged from 0 to 675 days. Incomplete lesion coverage by angiography was identified in 4 of 14 cases, malapposition by OCT in 5 of 9 cases, strut discontinuity in 2 of 9 cases, and underexpansion in 2 of 9 cases. Five patients had discontinued dual antiplatelet therapy, and in 3 of them discontinued dual antiplatelet therapy discontinuation had occurred the week preceding the event. There were no significant differences in angiographic or OCT findings between BVS and metallic stent thrombosis. Conclusions—Suboptimal implantation with incomplete lesion coverage, underexpansion, and malapposition comprises the main pathomechanism for both early and late BVS thrombosis, similar to metallic stent thrombosis. Dual antiplatelet therapy discontinuation seems to also be a secondary contributor in several late events. Our observations suggest that several potential triggers for BVS thrombosis could be avoided.

Frequency of Conduction Abnormalities After Transcatheter Aortic Valve Implantation With the Medtronic-CoreValve and the Effect on Left Ventricular Ejection Fraction

New conduction abnormalities occur frequently after transcatheter aortic valve implantation (TAVI). The relation between new conduction disorders and left ventricular (LV) systolic function after TAVI is unknown. The purpose of the present prospective, single-center study was to investigate the effect of TAVI on LV systolic function in relation to TAVI-induced conduction abnormalities. A total of 27 patients had undergone electrocardiography and transthoracic echocardiography the day before and 6 days after TAVI with the Medtronic-CoreValve system. The LV ejection fraction (EF) was calculated using the biplane Simpson method. The systolic mitral annular velocities and longitudinal strain were measured using speckle tracking echocardiography. After TAVI, 18 patients (67%) had new conduction abnormalities; 4 (15%) had a new paced rhythm and 14 patients (52%) had new left bundle branch block. In the patients with new conduction abnormalities, the EF decreased from 47 ± 12% to 44 ± 10%. In contrast, in those without new conduction abnormalities, the EF increased from 49 ± 12% to 54% ± 12%. The change in EF was significantly different among those with and without new conduction abnormalities (p <0.05). In patients without new conduction abnormalities, an improvement was found in the systolic mitral annular velocities and longitudinal strain (p <0.05). In contrast, in patients with new conduction abnormalities, the changes were not significant. In conclusion, the induction of new conduction abnormalities after TAVI with the Medtronic-CoreValve was associated with a lack of improvement in LV systolic function.

Influence of the pattern of hypertrophy on left ventricular twist in hypertrophic cardiomyopathy

Background/objective: Left ventricular (LV) twist has an important role in LV function. The influence of the pattern of LV hypertrophy on LV twist in hypertrophic cardiomyopathy (HCM) patients is unknown. This study sought to assess LV twist in a large group of HCM patients according to the pattern of LV hypertrophy. Methods: The final study population consisted of 43 patients with HCM (mean age 43 (15) years, 31 men) and a typical sigmoidal (nu200a=u200a16) or reverse septal curvature (nu200a=u200a27) and 43 age-matched and gender-matched healthy control subjects. LV peak systolic rotation (Rotmax), LV peak systolic twist (Twistmax) and untwisting at 5%, 10% and 15% of diastole were determined by speckle tracking echocardiography (STE). Results: Compared to control subjects, HCM patients had increased basal Rotmax (−5.5° (2.3°) vs −3.4° (1.7°), p<0.001) and comparable apical Rotmax (7.3° (3.1°) vs 7.0° (2.2°), pu200a=u200aNS), resulting in increased Twistmax (12.4° (4.0°) vs 9.9° (2.7°), p<0.01). Untwisting at 5%, 10% and 15% of diastole was decreased in HCM patients (all p<0.05). There was a striking difference in apical Rotmax (9.4° (2.8°) vs 6.0° (2.6°), p<0.01) and Twistmax (15.3° (3.2°) vs 10.6° (3.3°), p<0.01) between HCM patients with a sigmoidal and reverse septal curvature. Conclusions: STE may provide novel non-invasive indices to assess LV function in patients with HCM. Apical Rotmax and Twistmax in HCM patients are dependent on the pattern of LV hypertrophy.

The Rotterdam Radial Access Research: Ultrasound-Based Radial Artery Evaluation for Diagnostic and Therapeutic Coronary Procedures.

Background—Radial artery wall might be damaged after cannulation for cardiac catheterization. We investigated structural changes of the radial artery wall after catheterization to understand whether these might predict radial pulsation loss or occlusion and local pain or functional impairment of the upper extremity. Methods and Results—Ninety patients underwent transradial coronary angiography or intervention and were scanned with a high-resolution 40-MHz ultrasound before cannulation and at 3 hours and 30 days after procedure. Acute injuries of the radial artery occurred in all patients: dissection and intramural hematoma were the most common. However, these phenomena did not predict loss of radial pulsation or occlusion, local pain, or functional impairment at 30 days. Overall, the radial artery lumen was significantly reduced distal to the puncture site. Radial artery intima and total wall thickness increased 3 hours after puncture and persisted at 30 days. Radial occlusion and pulsation loss were observed in 3.9% and 9.2% of patients, respectively, at 30 days. Smaller radial artery lumen at baseline increased the risk of radial pulsation loss at 30 days (odds ratio, 1.23; P=0.049). The number of radial puncture attempts predicted pulsation loss (odds ratio, 2.64; P=0.027), occlusion (odds ratio, 3.49; P=0.022), and symptoms (odds ratio, 2.24; P=0.05) at 30-day follow-up. Conclusions—After catheterization, radial artery puncture site is associated with increased intima and total wall thickness and with modest decrease of inner lumen diameter. Acute injuries of the vessel wall were ubiquitous, but contrary to repeated puncture attempts, did not seem to affect postprocedural radial occlusion or loss of pulsation.

Role of left ventricular twist mechanics in cardiomyopathies, dance of the helices.

Left ventricular twist is an essential part of left ventricular function. Nevertheless, knowledge is limited in the cardiology community as it comes to twist mechanics. Fortunately the development of speckle tracking echocardiography, allowing accurate, reproducible and rapid bedside assessment of left ventricular twist, has boosted the interest in this important mechanical aspect of left ventricular deformation. Although the fundamental physiological role of left ventricular twist is undisputable, the clinical relevance of assessment of left ventricular twist in cardiomyopathies still needs to be established. The fact remains; analysis of left ventricular twist mechanics has already provided substantial pathophysiological understanding on a comprehensive variety of cardiomyopathies. It has become clear that increased left ventricular twist in for example hypertrophic cardiomyopathy may be an early sign of subendocardial (microvascular) dysfunction. Furthermore, decreased left ventricular twist may be caused by left ventricular dilatation or an extensive myocardial scar. Finally, the detection of left ventricular rigid body rotation in noncompaction cardiomyopathy may provide an indispensible method to objectively confirm this difficult diagnosis. All this endorses the value of left ventricular twist in the field of cardiomyopathies and may further encourage the implementation of left ventricular twist parameters in the diagnostic toolbox for cardiomyopathies.

Response by Costa et al to Letter Regarding Article, "The Rotterdam Radial Access Research: Ultrasound-Based Radial Artery Evaluation for Diagnostic and Therapeutic Coronary Procedures".

In response to the comments of Chugh et al on our study,1 we would like to point out that the rate of radial artery occlusion (RAO) ranged from <1% to 30% in recent studies (mean 7.89%), whereas in the Rotterdam Radial Access Research study, this was <4% at all time points.1 The incidence of RAO varies and seems multifactorial, including anatomic substrate (ie, vessel size), access technique, and access management before, during, and after the procedure. Our study underscores the clinical importance of number of radial punctures to obtain arterial access …