Carl Schultz

Anatomy of the Aortic Valvar Complex and Its Implications for Transcatheter Implantation of the Aortic Valve

The books and articles devoted to the anatomy of the aortic valvar complex are numerous. Until now, however, little consideration has been given to understanding the anatomy with percutaneous valvar replacement in mind. It is axiomatic that knowledge of the anatomy of the valve is fundamental in understanding key principles involved in valvar replacement. Such an appreciation of the anatomy helps better understand the optimal positioning for the prosthetic valve within the root of the aortia with respect to the coronary arteries, mitral valve, and the conduction system and may circumvent complications that can arise during its implantation. In this review, therefore, we describe the anatomy of the trifoliate aortic valvar complex and its implications for percutaneous valvar replacement.

Persistent conduction abnormalities and requirements for pacemaking six months after transcatheter aortic valve implantation

AIMS Early conduction abnormalities and need for pacemaking after transcatheter aortic valve implantation (TAVI) is well recognised. It is still unknown, however, if these conduction abnormalities are persistent, and what is the need for permanent pacemaking after 1-month follow-up. In this prospective study, we examined the incidence of post-procedural and 6-month conduction abnormalities and need for permanent pacemaking after TAVI. METHODS AND RESULTS We examined the 12-lead electrocardiogram (ECG) of 91 consecutive patients in whom a Medtronic CoreValve ReValving System was implanted between November 2005 and April 2009. We evaluated the ECGs before treatment, after treatment, at 1-month and 6-month follow-up. The requirement and timing of permanent pacemaking was documented. The mean age of patients was 81±7 years and the mean logistic EuroSCORE was 16±9%. Median duration of follow-up was 213 days (IQR 64, 519). There was a 39% increase in the frequency of LBBB after TAVI (15% before treatment vs. 54% after treatment, p<0.001). Importantly, there was no significant change in the frequency of LBBB from after treatment to 1- or 6-month follow-up (54% after treatment vs. 42% at 1-month follow-up, p=0.45, and 54% after treatment vs. 45% at 6-month follow-up, p=0.39). Permanent pacemaking was required in 17/91 (19%) of patients. A permanent pacemaker was implanted in 8/17 patients (47%) within seven days of TAVI, in 6/17 (35%) at 7-30 days, and in 3/17 (18%) after 30 days. Male gender, previous myocardial infarction, pre-existing right bundle branch block, actual diameter (mm) of the inflow portion of the CoreValve frame post-implantation and depth of implantation were predictors for new LBBB; pre-treatment QRS duration (msec) and septal wall thickness were predictors for permanent pacemaking. CONCLUSIONS These results suggest that early conduction abnormalities occurring after TAVI persist at 6-months follow-up. Patient-related, anatomical-related, and procedure-related factors need to be considered in the pathogenesis of conduction abnormalities after TAVI.

Aortic annulus dimensions and leaflet calcification from contrast MSCT predict the need for balloon post-dilatation after TAVI with the Medtronic CoreValve prosthesis

AIMS We compared the measurement of aortic leaflet calcification on contrast and non-contrast MSCT and investigated predictors of the need for balloon post-dilatation after TAVI. METHODS AND RESULTS In 110 patients, who had TAVI with a Medtronic CoreValve prosthesis (MCS) for symptomatic aortic stenosis, calcification of the aortic root was measured on non-contrast MSCT (conventionally) and on contrast MSCT (signal attenuation >450 Houndsfield units). Calcium volume was underestimated on contrast- when compared to non-contrast MSCT: median (IQ-range)=759 (466 to 1295) vs. 2016 (1376 to 3262) and the difference between the two methods increased with higher calcium volumes (correlation coefficient r=0.90). Calcium mass was only slightly underestimated on contrast vs. non-contrast MSCT: median (IQ-range)=441 (268 to 809) vs. 555 (341 to 950) and there was no association between the differences and increasing calcium mass (r=0.17). Balloon post-dilatation was performed for significant aortic regurgitation after TAVI in 11 of 110 patients. When compared to controls, the patients who required balloon post-dilatation had higher aortic leaflet calcium on contrast CT (p<0.01), higher aortic annulus diameters (p<0.01) and higher annulus to prosthesis area ratio (p=0.01). ROC curves demonstrated that aortic root or aortic leaflet calcium measured on either contrast- or non-contrast MSCT showed excellent discrimination for the requirement of balloon post-dilatation (area under ROC >0.80 for all), whereas the discriminatory value of aortic annulus dimensions was moderate (area under ROC=0.69) and that of prosthesis to annulus ratio was poor (area under ROC=0.36). CONCLUSIONS Dense aortic leaflet calcification measured on contrast MSCT discerned well the need for balloon post-dilatation after TAVI with an MCS for significant PAR. Non-contrast MSCT may no longer be needed to quantify aortic root calcium before TAVI.

First-in-man evaluation of intravascular optical frequency domain imaging (OFDI) of Terumo: a comparison with intravascular ultrasound and quantitative coronary angiography.

AIMS The objective of this study is to evaluate the feasibility and safety of imaging human coronary arteries in vivo by optical frequency domain imaging (OFDI) in comparison to intravascular ultrasound (IVUS). OFDI has been recently developed to overcome the limitations of conventional time-domain optical coherence tomography (OCT), namely the need for proximal balloon occlusion. The Terumo-OFDI system is capable of acquiring images with high-speed automated pullback (up to 40 mm/sec) and requires only a short injection (3-4 sec) of small amount of x-ray contrast (9-16 ml). METHODS AND RESULTS Nineteen patients who underwent stent implantation were enrolled. IVUS/OFDI were performed before and after stenting. The incidences of any adverse event and angiographic adverse findings were recorded. Lumen area (LA) was measured by IVUS and OFDI at 1 mm intervals in the stented segments (n=19) as well as in the proximal, distal, and to-be-stented segments (n=40). In addition, lumen area in the stented segment was also measured by edge (E-) and video-densitometric (VD-) quantitative coronary angiography (QCA). The OFDI images were obtained without any adverse event related to imaging procedures. Post stenting (n=19), minimal LA (MLA) measured by OFDI (5.84 ± 1.89 mm2) was larger than that of E-QCA (4.16 ± 1.46 mm2, p<0.001) and VD-QCA (4.92 ± 1.55 mm2, p<0.05). It was smaller than IVUS-MLA (6.26 ± 2.01 mm2, N.S.) but the correlation between the two measurements was highly significant (R2=0.82, p<0.001). CONCLUSIONS The OFDI imaging is feasible both before and after stenting and has a promising safety profile. The OFDI provided clear high resolution images and robust lumen measurements.

First use in patients of a combined near infra-red spectroscopy and intra-vascular ultrasound catheter to identify composition and structure of coronary plaque

A 70 year-old diabetic female with a history of hyperlipidaemia treated with statin therapy underwent coronary angioplasty of her right coronary artery (RCA, Figure 1). Post-procedure the RCA was assessed using, for the first time, a combination intravascular ultrasound (IVUS) and near infrared spectroscopy (NIRS) catheter, which indicated that the proximal end of the stent was located in an area of lipid core plaque (Figure 2 and Video 1); a potential risk factor for stent thrombosis.1 Prospective studies are needed to assess the risk of ending a stent in a fibroatheroma, and to investigate the use of NIRS-IVUS to determine the optimal landing zone for a stent. In this manner, the co-localization of lipid core with structure may provide useful information that will enhance the safety of stenting and, with prospective studies, increase the ability to correctly identify plaque at risk of rupture.

Prevalence and prognostic implications of baseline anaemia in patients undergoing transcatheter aortic valve implantation.

AIMS TAVI is a minimally invasive alternative to surgical aortic valve replacement or medical therapy in patients with a high or prohibitive operative risk. The clinical significance of baseline anemia and prognostic implications in this patient cohort are unknown. We sought to evaluate the prevalence and prognostic implications of baseline anaemia in patients undergoing transcatheter aortic valve implantation (TAVI) at our institution. METHODS AND RESULTS One hundred and eighteen consecutive patients who underwent TAVI with the Medtronic Corevalve System (Medtronic Corp., Minneapolis, MN, USA) were included in the analysis. Clinical and biochemical data were prospectively collected before, during and after the procedure. Clinical follow-up was set at one month, one year and yearly thereafter. Anaemia was defined as a haemoglobin level <13 g/dL in men and <12 g/dL in women. Mortality was confirmed by consultation of the civil registry. The prevalence of baseline anaemia was 49%. Anaemic patients undergoing TAVI required more RBC transfusions (3.3 ± 3.1 versus 1.5 ± 2.3; p<0.001) and more frequently experienced a prolonged index hospitalisation exceeding two weeks. For patients with at least 1-year follow up (N=74), mortality at 30 days was no different; however 1-year mortality was significantly higher in the anaemic cohort (44 versus 15%, p=0.006). In a multivariable analysis, baseline anaemia emerged as an independent predictor of 1- year mortality (HR 2.10 [1.06-4.18]). CONCLUSIONS In our series, baseline anaemia is common in patients undergoing TAVI, forecasts a need for more red blood cell transfusions and is associated with increased 1-year mortality.

Coronary CT Angiography for Suspected ACS in the Era of High-Sensitivity Troponins: Randomized Multicenter Study.

BACKGROUND It is uncertain whether a diagnostic strategy supplemented by early coronary computed tomography angiography (CCTA) is superior to contemporary standard optimal care (SOC) encompassing high-sensitivity troponin assays (hs-troponins) for patients suspected of acute coronary syndrome (ACS) in the emergency department (ED). OBJECTIVES This study assessed whether a diagnostic strategy supplemented by early CCTA improves clinical effectiveness compared with contemporary SOC. METHODS In a prospective, open-label, multicenter, randomized trial, we enrolled patients presenting with symptoms suggestive of an ACS at the ED of 5 community and 2 university hospitals in the Netherlands. Exclusion criteria included the need for urgent cardiac catheterization and history of ACS or coronary revascularization. The primary endpoint was the number of patients identified with significant coronary artery disease requiring revascularization within 30 days. RESULTS The study population consisted of 500 patients, of whom 236 (47%) were women (mean age 54 ± 10 years). There was no difference in the primary endpoint (22 [9%] patients underwent coronary revascularization within 30 days in the CCTA group and 17 [7%] in the SOC group [p = 0.40]). Discharge from the ED was not more frequent after CCTA (65% vs. 59%, p = 0.16), and length of stay was similar (6.3 h in both groups; p = 0.80). The CCTA group had lower direct medical costs (€337 vs. €511, p < 0.01) and less outpatient testing after the index ED visit (10 [4%] vs. 26 [10%], p < 0.01). There was no difference in incidence of undetected ACS. CONCLUSIONS CCTA, applied early in the work-up of suspected ACS, is safe and associated with less outpatient testing and lower costs. However, in the era of hs-troponins, CCTA does not identify more patients with significant CAD requiring coronary revascularization, shorten hospital stay, or allow for more direct discharge from the ED. (Better Evaluation of Acute Chest Pain with Computed Tomography Angiography [BEACON]; NCT01413282).

The use of MSCT for the evaluation of the aortic root before transcutaneous aortic valve implantation: the Rotterdam approach.

AIMS Whereas transthoracic echocardiography is the modality of choice for the diagnosis of severe aortic stenosis and cine-fluoroscopy is used to guide the implantation of the TAVI prosthesis, we believe that multislice computer tomography (MSCT) is the modality of choice for evaluation of the aortic root with a view to selecting patients with suitable anatomy and to guide sizing. We aim to describe an anatomical approach for the step by step interrogation of a 3D MSCT dataset to obtain the measurements of the aortic root required for patient selection, sizing and selection of the optimal angulation of the C-arm during the implantation procedure. METHODS AND RESULTS The landmarks used to anatomically define the aortic annulus and structures of the aortic root may be used to define the same structures for measurement on a 3D MSCT dataset by setting up orthogonal cut-planes including one axial to the aortic annulus. This allows true axial diameter measurements and also enables us to define the valve plane. CONCLUSIONS Measurement on the axial images avoids incorrect diameter measurements that do not pass through the central axis.

Frequency of familial hypercholesterolemia in patients with early-onset coronary artery disease admitted to a coronary care unit

BACKGROUND Familial hypercholesterolemia (FH) is the most common dominantly inherited cause of premature coronary artery disease (CAD). However, the diagnosis of FH in patients who have premature CAD in hospital settings is under-recognized, this also represents a missed opportunity for screening their close family members and implementing primary prevention. OBJECTIVE To investigate the point prevalence of FH in a coronary care unit (CCU) among patients with early-onset CAD. METHODS The prevalence of FH, based on modified phenotypic Dutch Lipid Clinic Network Criteria, and the spectrum of associated CAD risk factors, were investigated in a CCU setting. Data were collected on 175 coronary care patients with onset of CAD at age <60 years. RESULTS The prevalence of probable/definite FH was 14.3% (95% confidence interval, 9.0%-19.5%); 46.3% of the patients gave a family history of premature CAD and 20.6% had an untreated low-density lipoprotein cholesterol >5.0 mmol/L. Diabetes, hypertension, obesity, and smoking were common and equally prevalent in patients with and without FH. CONCLUSIONS FH is relatively frequent among patients with a history of early-onset CAD in the CCU. Every effort should be made to detect FH in these patients and to initiate cascade testing of available family members to prevent the development of CAD in those who may be unaware that they also have the condition.

Quantitative Computed Tomographic Coronary Angiography Does It Predict Functionally Significant Coronary Stenoses

Background—Coronary lesions with a diameter narrowing ≥50% on visual computed tomographic coronary angiography (CTCA) are generally considered for referral to invasive coronary angiography. However, similar to invasive coronary angiography, visual CTCA is often inaccurate in detecting functionally significant coronary lesions. We sought to compare the diagnostic performance of quantitative CTCA with visual CTCA for the detection of functionally significant coronary lesions using fractional flow reserve (FFR) as the reference standard. Methods and Results—CTCA and FFR measurements were obtained in 99 symptomatic patients. In total, 144 coronary lesions detected on CTCA were visually graded for stenosis severity. Quantitative CTCA measurements included lesion length, minimal area diameter, % area stenosis, minimal lumen diameter, % diameter stenosis, and plaque burden [(vessel area−lumen area)/vessel area×100]. Optimal cutoff values of CTCA-derived parameters were determined, and their diagnostic accuracy for the detection of flow-limiting coronary lesions (FFR ⩽0.80) was compared with visual CTCA. FFR was ⩽0.80 in 54 of 144 (38%) coronary lesions. Optimal cutoff values to predict flow-limiting coronary lesion were 10 mm for lesion length, 1.8 mm2 for minimal area diameter, 73% for % area stenosis, 1.5 mm for minimal lumen diameter, 48% for % diameter stenosis, and 76% for plaque burden. No significant difference in sensitivity was found between visual CTCA and quantitative CTCA parameters (P>0.05). The specificity of visual CTCA (42%; 95% confidence interval [CI], 31%–54%) was lower than that of minimal area diameter (68%; 95% CI, 57%–77%; P=0.001), % area stenosis (76%; 95% CI, 65%–84%; P<0.001), minimal lumen diameter (67%; 95% CI, 55%–76%; P=0.001), % diameter stenosis (72%; 95% CI, 62%–80%; P<0.001), and plaque burden (63%; 95% CI, 52%–73%; P=0.004). The specificity of lesion length was comparable with that of visual CTCA. Conclusions—Quantitative CTCA improves the prediction of functionally significant coronary lesions compared with visual CTCA assessment but remains insufficient. Functional assessment is still required in lesions of moderate stenosis to accurately detect impaired FFR.