Arterial compliance adds to conventional risk factors for prediction of angiographic coronary artery disease

Background

Arterial compliance is related to left ventricular hypertrophy and risk for cardiovascular disease events; however, its association with coronary artery stenosis remains uncertain. We sought to assess the relation between lower extremity arterial compliance and presence of angiographically defined coronary artery disease.

Methods

Lower extremity arterial compliance was measured with the use of a noninvasive air plethysmography technique in 376 subjects undergoing routine diagnostic coronary angiography.

Results

Measures of calf arterial compliance were significantly associated with the presence of one or more stenoses ≥50% compared with no stenoses, even after adjustment for age, sex, smoking, diabetes, hypertension, hypercholesterolemia, and obesity (P = .03). Measures of thigh arterial compliance were also lower in subjects with disease, although this association did not reach statistical significance (P = .07). Receiver operator curves illustrate the incremental predictive ability of calf arterial compliance over and above age, sex, and conventional risk factors.

Conclusions

Lower extremity arterial compliance is associated with presence of significant coronary stenoses in a cardiac catheterization laboratory referral population. This observation lends support for additional efforts to determine the utility of vascular stiffness measures in both clinical and pre-clinical populations to guide treatment and prevention efforts.     

Toward magnetic resonance-guided electroanatomical voltage mapping for catheter ablation of scar-related ventricular tachycardia: a comparison of registration methods

Toward MR‐Guided Electroanatomical Voltage Mapping for Catheter Ablation. Introduction: Integration of preprocedural delayed enhanced magnetic resonance imaging (DE‐MRI) with electroanatomical voltage mapping (EAVM) may provide additional high‐resolution substrate information for catheter ablation of scar‐related ventricular tachycardias (VT). Accurate and fast image integration of DE‐MRI with EAVM is desirable for MR‐guided ablation. Methods and Results: Twenty‐six VT patients with large transmural scar underwent catheter ablation and preprocedural DE‐MRI. With different registration models and EAVM input, 3 image integration methods were evaluated and compared to the commercial registration module CartoMerge. The performance was evaluated both in terms of distance measure that describes surface matching, and correlation measure that describes actual scar correspondence. Compared to CartoMerge, the method that uses the translation‐and‐rotation model and high‐density EAVM input resulted in a registration error of 4.32±0.69 mm as compared to 4.84 ± 1.07 (P <0.05); the method that uses the translation model and high‐density EAVM input resulted in a registration error of 4.60 ± 0.65 mm (P = NS); and the method that uses the translation model and a single anatomical landmark input resulted in a registration error of 6.58 ± 1.63 mm (P < 0.05). No significant difference in scar correlation was observed between all 3 methods and CartoMerge (P = NS). Conclusions: During VT ablation procedures, accurate integration of EAVM and DE‐MRI can be achieved using a translation registration model and a single anatomical landmark. This model allows for image integration in minimal mapping time and is likely to reduce fluoroscopy time and increase procedure efficacy. (J Cardiovasc Electrophysiol, Vol. 23, pp. 74‐80, January 2012)     

Six-year follow-up of a point-source exposure to CWD contaminated venison in an Upstate New York community: risk behaviours and health outcomes 2005–2011

Objectives

It is currently unknown whether chronic wasting disease (CWD), a transmissible spongiform encephalopathy of cervids, is transmissible to humans. Reported on here are the behavioural risk factors and health conditions associated with a six-year follow-up of a known point-source exposure to a CWD infected deer in an Upstate New York community.

Study design

Longitudinal.

Methods

The Oneida County Chronic Wasting Disease Surveillance Project was launched in 2005 in response to a point-source exposure to a CWD infected deer at a March 2005 Sportsmen's feast in Upstate New York. Eighty-one exposed individuals participated in the 2005 baseline data collection, and were sent follow-up questionnaires following each deer hunting season between 2005 and 2011.

Results

Over a six year period, participants reported a reduction in overall venison consumption. Participants reported no significant changes in health conditions, although several conditions (vision loss, heart disease, type 2 diabetes, weight changes, hypertension, and arthritis), were significantly associated with age.

Conclusions

To this day, this incident remains the only known large-scale point-source exposure to a CWD infected deer. Prion diseases can incubate for multiple decades before the manifestation of clinical symptoms; thus, continued surveillance of this exposed study population represents a unique opportunity to assess the risk of CWD transmission to humans. This project is uniquely situated to provide the first epidemiological evidence of CWD transmission to humans, should it occur.     

Predictors of coronary in-stent restenosis: importance of angiotensin-converting enzyme gene polymorphism and treatment with angiotensin-converting enzyme inhibitors

OBJECTIVES: This study aimed to clarify the role of the angiotensin-converting enzyme (ACE) gene polymorphism in the development of in-stent restenosis. BACKGROUND: In-stent restenosis occurs after treatment of coronary artery stenosis in 12% to 32% of coronary interventions with stents. Experimental and clinical studies have suggested that the deletion/insertion (D/I) polymorphism of the ACE gene plays a role in this. METHODS: Quantitative coronary angiography before, immediately after and six months after stent implantation were compared in 369 patients, in whom D/I typing of the ACE gene was performed. RESULTS: At follow-up we found no differences between the three genotypes in minimal lumen diameter (homozygotes with two deletion alleles in the ACE gene [DD], 2.20 mm; heterozygotes with one deletion and one insertion allele in the ACE gene [DI], 2.19 mm; and homozygotes with two insertion alleles in the ACE gene [II], 2.25 mm). The corresponding diameter stenoses were: DD: 25%, DI: 27%, II: 27% (p = NS), and the frequency of restenosis (>50% diameter stenosis) was: DD: 15.7%, DI: 11.0% and II: 16.4% (p = NS). Logistic regression analysis identified diabetes (odds ratio [OR]: 3.0, 95% confidence interval [CI]: 1.0 to 8.7), lesion length (OR: 1.1, 95% CI: 1.01 to 1.30) and minimal lumen diameter immediately after the intervention (OR: 0.3, 95% CI: 0.14 to 0.85) as predictors of in-stent restenosis. In a post hoc analysis of patients treated versus those not treated with an ACE-inhibitor antagonist or an angiotensin receptor antagonist, we found an increased frequency of in-stent restenosis in the DD genotypes (40% vs. 12%, p = 0.006). CONCLUSIONS: The D/I polymorphism is not an independent predictor of coronary in-stent restenosis in general, but it may be of clinical importance in patients treated with ACE inhibitors or angiotensin receptor antagonists.     

Factors Influencing Disease Self-Management Among Veterans with Diabetes and Poor Glycemic Control

BACKGROUND: Federal laws and regulations, including the Health Insurance Portability and Accountability Act (HIPAA) of 1996, intended primarily to protect individuals, have been described as significant barriers to the use of clinical registries and other population-based tools for health care research. Although these regulations allow for the waiver or alteration of usual consent procedures when the research meets certain specific criteria, waivers and alterations are rarely used in health care research. METHODS: The Vermont Diabetes Information System is a multistate randomized trial of a quality improvement intervention that uses a novel alteration of informed consent to help ensure that the study sample is representative of the target population. Patients are notified by mail that they are eligible for the study and that they may opt out of the study, if they desire, by calling a toll-free number. RESULTS: Seven thousand five hundred and fifty-eight patients were invited to participate. Two hundred and ten (2.8%) opted out. Three patients (0.04%) filed complaints, all of which were addressed satisfactorly. CONCLUSIONS: Health Insurance Portability and Accountability Act and other federal regulations raise challenges to the use of clinical registries in research, but modifications to the consent process, including passive consent methods, are useful tools to overcome these challenges. It is possible to recruit a broad and representative population under current law while maintaining appropriate protections for research subjects. This work was presented at the Society for General Internal Medicine National and New England Regional Meetings and Academy Health in 2005. This work was funded by the National Institute of Diabetes and Digestive and Kidney Diseases (R01 DK61167 and K24 DK068380).     

Clinical application of quantitative coronary angiography using the CAAS system: Preliminary results of the INTACT study (international nifedipine trial on antiatherosclerotic therapy)

Summary It is the objective of the INTACT-study to test in man, whether a significant retardation of the progression of coronary artery disease is attainable with the Ca-antagonist nifedipine; this may be possible on the basis of numerous animal experiments. INTACT is a prospective, randomized, double blind, placebo controlled investigation in 423 patients with preferably early stages of coronary sclerosis in whom a progression of the disease seems likely. A proper coronary angiogram led to inclusion of the patients in the study (October 1983–June 1985). Over the following 3-years-period patients received either nifedipine 80 mg/day or placebo. The study is concluded by a control coronary angiogram with angiographic projections which are identical to those of the first coronary angiography. The extent of coronary sclerosis is objectivated by computer-assisted quantitative measurement of the entire coronary arterial system with the CAAS-system (Rotterdam). For definition purposes the coronary artery system subdivided into 25 segments. Parameters for progression assessment will be mean segment diameter, minimal obstruction diameter, percentage severity of obstruction, length of obstruction and plaque area.So far 4826 coronary segments have been analyzed from the first angiograms of 383 patients. Per patient an average of 12.6 different segments could be evaluated in at least one angiographic projection. The major coronary segments could be measured in 72–93% of the patients in one or more angiographic projections (at the average about 2 different projections). Five hundred and forty-six coronary obstructions were analyzed; 131 of these were total occlusions. Only 9% of the length of the vessel contours detected by the computer algorithm required manual correction by the operators, suggesting a high reliability of the system. It can be concluded that quantitative measurement of the complete coronary artery system can indeed be obtained in a large angiographical multicenter study such as INTACT.     

Clinical Implication of Quantitative Flow Ratio After Percutaneous Coronary Intervention for 3-Vessel Disease

ObjectivesThe aim of this study was to investigate the impact of post–percutaneous coronary intervention (PCI) quantitative flow ratio (QFR) on clinical outcomes in patients with de novo 3-vessel disease (3VD) treated with contemporary PCI.BackgroundThe clinical impact of post-PCI QFR in patients treated with state-of-the-art PCI for de novo 3VD is undetermined.MethodsAll vessels treated in the SYNTAX (SYNergy between percutaneous coronary intervention with TAXus and cardiac surgery) II trial were retrospectively screened and analyzed for post-PCI QFR. The primary endpoint of this substudy was vessel-oriented composite endpoint (VOCE) at 2 years, defined as the composite of vessel-related cardiac death, vessel-related myocardial infarction, and target vessel revascularization. The receiver-operating characteristic curve was used to calculate the optimal cutoff value of post-PCI QFR for predicting 2-year VOCE. All the analyzable vessels were stratified on the basis of the optimal cutoff value.ResultsA total of 968 vessels treated with PCI were screened. Post-PCI QFR was analyzable in 771 (79.6%) vessels. A total of 52 (6.7%) VOCEs occurred at 2 years. The mean value of post-PCI QFR was 0.91 ± 0.07. The diagnostic performance of post-PCI QFR to predict 2-year VOCE was moderate (area under the curve: 0.702; 95% confidence interval: 0.633 to 0.772), with the optimal cutoff value of post-PCI QFR for predicting 2-year VOCE 0.91 (sensitivity 0.652, specificity 0.635). The incidence of 2-year VOCE in the vessels with post-PCI QFR <0.91 (n = 284) was significantly higher compared with vessels with post-PCI QFR ≥0.91 (n = 487) (12.0% vs. 3.7%; hazard ratio: 3.37; 95% confidence interval: 1.91 to 5.97; p < 0.001).ConclusionsA higher post-PCI QFR value is associated with improved vessel-related clinical outcomes in state-of-the art PCI practice for de novo 3VD. Achieving a post-PCI QFR value ≥0.91 in all treated vessels should be a target when treating de novo 3VD. These findings require confirmation in future prospective trials.     

Assessment of left ventricular dyssynchrony in patients with conduction delay and idiopathic dilated cardiomyopathy: head-to-head comparison between tissue doppler imaging and velocity-encoded magnetic resonance imaging.

OBJECTIVES: This study sought to compare tissue Doppler imaging (TDI) with velocity-encoded (VE) magnetic resonance imaging (MRI) for left ventricular (LV) dyssynchrony assessment. BACKGROUND: Cardiac resynchronization therapy (CRT) is proposed for patients with heart failure, depressed LV function, and a wide QRS complex. Selection is based mainly on electrocardiogram criteria, but recent data suggest that intraventricular dyssynchrony may be preferred for selection. An LV dyssynchrony can adequately be assessed with TDI, but this has not been compared directly with other imaging modalities. A VE MRI potentially allows direct myocardial wall motion measurements similar to TDI. METHODS: Twenty patients with heart failure, systolic LV dysfunction, and a wide QRS complex were included, as well as 10 normal individuals with normal QRS duration and LV function. The TDI and VE MRI data were acquired to study intraventricular dyssynchrony. RESULTS: Left ventricular dyssynchrony was not observed in normal individuals (mean dyssynchrony -2 +/- 15 ms on TDI; mean -5 +/- 17 ms on MRI, p = NS). In patients, mean LV dyssynchrony was 55 +/- 37 ms on TDI; 49 +/- 38 ms on MRI (p = NS). Good correlation between both modalities was observed (linear regression TDI = 0.99 x MRI - 5, n = 30, r = 0.98, p < 0.01). The MRI showed a small, nonsignificant underestimation of 5 +/- 8 ms compared with TDI. Agreement between MRI and TDI for classification according to severity of LV dyssynchrony (minimal, intermediate, and extensive) was excellent (kappa +/- SE = 0.96 +/- 0.07, p < 0.01) with 95% of patients classified identical. CONCLUSIONS: Both MRI and TDI yield comparable information on LV dyssynchrony; MRI is useful in the selection of patients for CRT.     

A novel three‐dimensional quantitative coronary angiography system: In‐vivo comparison with intravascular ultrasound for assessing arterial segment length

Background : Accurate on‐line assessments of vessel dimensions are of utmost importance for selecting the appropriate stent size in coronary interventions. Recently a new three‐dimensional quantitative coronary angiography (3D QCA) analytical software package was developed to accurately assess the vessel dimensions for the planning and guidance of such coronary interventions. This study aimed to validate the 3D QCA software package for assessing arterial segment length by comparing with intravascular ultrasound (IVUS). In addition, the difference in the two measurements from 3D QCA and IVUS for curved segments was studied. Methods : A retrospective study including 20 patients undergoing both coronary angiography and IVUS examinations of the left coronary artery was set up for the validation. The same vessel segments of interest between proximal and distal markers were identified and measured on both angiographic and IVUS images, by the 3D QCA software and by a quantitative IVUS software package, respectively. In addition, the curvature of each of the segments of interest was assessed and the correlation between the accumulated curvature of the segment and the difference in segment lengths measured from the two imaging modalities was analyzed. Results : 37 vessel segments of interest were identified from both angiographic and IVUS images. The 3D QCA segment length was slightly longer than the IVUS segment length (15.42 ± 6.02 mm vs. 15.12 ± 5.81 mm, P = 0.040). The linear correlation of the two measurements was: 3D QCA Length = ?0.09 + 1.03 × IVUS Length (r² = 0.98, P < 0.001). Bland‐Altman plot showed that the difference in the two measurements was not correlated with the average of the two measurements (P = 0.141), but with the accumulated curvature of the segment (P = 0.015). After refining the difference by the correlation, the average difference of the two measurements decreased from 0.30 ± 0.86 mm (P = 0.040) to 0.00 ± 0.78 mm (P = 0.977). Conclusions : The 3D QCA software package can accurately assess the actual arterial segment length. The difference in segment lengths measured from 3D QCA and IVUS was correlated with the accumulated curvature of the segment. © 2010 Wiley‐Liss, Inc.     

Movement and heart acceleration behavior of eutrophic fetuses in the early and late dilatation period

The degree of fetal respiratory and body movements as well as of fetal heart rate reactivity was checked by synchronous ultrasonic and cardiographic monitoring of 18 normotrophic fetuses in the early and late dilation period. Apart from the fetal respiratory movements, which could no longer be observed in the late dilatation period, the degree of fetal body movements remained unaffected during the birth process. In the late dilatation period, the mean amplitude of heart rate accelerations occurring in association with fetal body movements was significantly lower than in the early dilatation period. In the unimpaired normotrophic fetus, however, the reactivity of the fetal cardiovascular system increased during the birth process in relation to the ratio of the amplitude of heart rate accelerations and the duration of associated fetal body movements. Hence, a decrease in fetal heart rate reactivity signals intranatal disturbance of the materno-utero-placento-fetal entity.