Clinical implication of adenosine-stress cardiac magnetic resonance imaging as potential gatekeeper prior to invasive examination in patients with AHA/ACC class II indication for coronary angiography

BACKGROUND : Real world cardiology is faced with a low diagnostic yield of coronary angiography (CXA) in patients presenting with ACC/AHA class II CXA indication. Our aim was to analyze the clinical implication of a Cardiac MR (CMR) protocol including adenosine stress perfusion in this patient population. We examined whether CMR could enhance appropriate CXA indication and thus reduce the rate of pure diagnostic CXA. In addition, we compared the relative impact of CMR exam components (perfusion, function and viability assessment) in achieving this target. METHODS : 176 patients were referred for CXA with class II indication. 171 underwent complete additional CMR exam in a 1.5-T whole body CMR-scanner for myocardial function, ischemia and viability prior to CXA. The routine protocol for assessment of CAD consisted of functional imaging (long and short axes), adenosine stress- and rest-perfusion in short axis orientation and "late enhancement" imaging in long and short axes. Images were analyzed by two independent and blinded investigators. Interobserver differences were resolved by a third reader. RESULTS : There was a high association between CMR results and subsequent invasive findings (chi square for CMR perfusion deficit and stenosis >70% in CXA: 113.7, p<0.0001). 109 (63.7%) of our patients had relevant perfusion deficits as seen by CMR and matching coronary artery stenosis >70%. Four (2.3%) patients had false negative CMR findings. In 58 patients (33.9%) no relevant coronary artery stenosis could be observed, correctly predicted by CMR in 48 cases; in 10 (5.8%) patients CMR provided false positive results. Sensitivity of CMR to detect relevant CAD (>70% luminal narrowing) was 0.96, specificity 0.83, positive predictive value 0.92 and negative predictive value 0.92. Of the CMR components, perfusion deficit was the strongest independent predictor (odds ratio 132.3, p < 0.0001). CONCLUSION : In a great number of patients being referred to cath lab with ACC/AHA class II indication for CXA, CMR provides a high accuracy for decision making regarding appropriateness of the invasive exam. CMR prior to CXA could substantially reduce pure diagnostic coronary angiographies in patients with intermediate probability for CAD, in our patient-cohort from approximately 34% to 6%. Further studies are warranted to identify rare false negative CMR results.     

Coronary angioplasty in drug eluting stent era for the treatment of unprotected left main stenosis compared to coronary artery bypass grafting

Background. Improved outcomes of percutaneous coronary interventions (PCI) with drug-eluting stents (DES) have resulted in their expanded use for left main coronary artery (LMCA) stenosis.

Aim. We compared outcomes of patients undergoing PCI for unprotected LMCA stenosis and patients treated by coronary artery bypass grafting (CABG).

Method. Between January 2005 and January 2007, 6705 patients were studied with coronary angiography in northern Finland. All subjects treated with revascularization of LMCA stenosis (n=287) were included and followed up for a mean of 12±6 months.

Results. From 287 patients, 238 underwent CABG, and 49 had PCI with DES. The incidence of 1-year mortality was 4% among the PCI-treated and 11% among CABG-treated patients (P=0.136). After the first month, mortality among PCI- or CABG-treated patients did not differ statistically significantly (2% versus 7%, P=0.133). The most significant independent predictor of mortality was reduced left ventricular systolic function (hazard ratio 14.9, 95% CI 5.5–40.0, P<0.001).

Conclusions. PCI with DES for selected LMCA disease patients results in short- and midterm outcomes comparable to results of CABG in general. PCI is a viable therapeutic option in selected patients with LMCA stenosis.     

Combined coronary and perfusion cardiovascular magnetic resonance for the assessment of coronary artery stenosis.

The purpose of this study was to evaluate the feasibility and accuracy of combined coronary and perfusion cardiovascular magnetic resonance (CMR) in the assessment of coronary artery stenosis. Thirty-five consecutive patients (27 men, eight women, age range 34-81 years), undergoing cardiac catheterization, were assessed with 3D coronary CMR and rest-stress perfusion CMR. Significant coronary stenosis was determined by vessel narrowing or signal loss with coronary CMR, and by abnormal contrast enhancement with perfusion CMR. Coronary artery diameter stenosis greater than 50% was considered significant with conventional cardiac catheterization. Seventeen patients had significant coronary artery disease, and in these there were 35 significant stenoses on cardiac catheterization. All left main stem arteries were normal on both cardiac catheterization and coronary CMR. For the diagnosis of coronary artery stenosis, coronary CMR had a sensitivity of 92% for the left anterior descending artery (LAD), 79% for the right coronary artery (RCA), but only 13% for the circumflex coronary artery (LCX). Perfusion CMR had corresponding sensitivities of 69%, 86%, and 63%, respectively. For all arteries the accuracies for coronary and perfusion CMR were 67% and 72%, respectively. Combining coronary and perfusion CMR improved the accuracy to 77%. These data demonstrate that in patients with suspected coronary artery disease, combined coronary and perfusion CMR is feasible, increases the accuracy of detection of significant coronary stenosis, and offers the possibility of combined anatomical and hemodynamic assessment of coronary artery stenosis.     

Quantitative angiographic follow-up studies on the development of coronary artery disease: which coronary segments should be analyzed?

Angiographic follow-up studies on the evolution of coronary artery disease are of increasing relevance. It has still to be evaluated which coronary segments are predominantly involved in the process of atherosclerosis and, thus, should be preferably included in the analysis. Therefore, the correlation of progression and regression of coronary disease with the diameter and location (proximal, mid or distal) of coronary segments was investigated from the data of the INTACT-study, in which 25 different coronary segments were defined including anatomic variants of rather distal segments. In 348 patients with coronary artery disease, standardized coronary angiograms were repeated within 3 years and were quantitatively analyzed (CAAS). In 1063 coronary stenoses (% diameter stenosis > 20%) compared from both angiograms, progression and regression were not influenced by diameter nor location of arterial segments. In the follow-up angiograms, the number of new lesions (stenoses and occlusions) per coronary segment differed with regard to segment diameter (> 3 mm: 64/1125 (6%); 2–3 mm: 139/1967 (7%);<2 mm: 44/1756 (2%); p<0.001) and location of segments (proximal: 86/1285 (7%); mid: 84/1193 (7%); distal: 77/2370 (3%); p<0.001). Out of 77 distal new lesions, only 25 (32%) were found in segments<2 mm in diameter. Since the absolute number of new lesions was high in distal coronary segments, but low in segments with diameters<2 mm, angiographic follow-up studies should analyze coronary segments at any location, but may neglect segments with diameters smaller than 2 mm.     

Angiographically undetected plaque in the left main coronary artery

The absence of angiographic findings despite significant coronary artery disease has been previously described. Possible explanations for the limitation of plaque detection by angiography include compensatory vessel enlargement in face of intracoronary plaque formation, the lack of reference segments in diffuse atherosclerosis as well as technical limitations. Intracoronary ultrasound (ICUS) imaging provides the possibility of direct plaque visualization. We studied angiographically normal left main coronary arteries (LMCA) in 72 patients prior to diagnostic angiography or therapeutic interventions using ICUS (30 MHz). ICUS images were continuously recorded and recalled from memory for morphometric analysis. Lumen area, plaque area and the total vessel area were determined by computer software. ICUS imaging revealed atherosclerotic plaque in 55 of the 72 patients with angiographically normal LMCA (76%). The average plaque area stenosis was 22±12% (range 3–44%). Total vessel area showed a significant direct correlation with plaque area, indicating compensation of coronary plaque formation. The average percent change in plaque area (difference between maximal and minimal plaque area within the LMCA) was 11±19%, indicating a diffuse pattern. Measurement of change in lumen area (difference between maximal and minimal lumen area within the LMCA) revealed an average value of 6±7%. Lumen area of the LMCA was 15.9±3.2 mm² in patients with and 17.2±1.9 mm² without atherosclerotic plaque (n.s.). Thus, the lack of angiographic changes despite advanced plaque formation in the LMCA could be explained by compensatory vessel enlargement and by diffuse distribution of plaque in the vessel; true lumen narrowings overlooked by angiography seem not to account for the failure of angiography to detect plaque.     

Percutaneous coronary intervention as an alternative to bypass surgery for unprotected LMCA stenosis

Hemodynamically significant left main coronary artery (LMCA) stenosis is found in approximately 4% of diagnostic coronary angiograms and is known as unprotected LMCA stenosis if the left coronary artery and left circumflex artery have no patent previous grafts. Previous randomized studies have demonstrated a significant reduction in mortality when revascularization by coronary artery bypass graft (CABG) surgery was undertaken compared with medical treatment. Therefore, current practice guidelines do not recommend percutaneous coronary intervention (PCI) for such a lesion, owing to the proven benefit of surgery and high rates of restenosis with the use of bare metal stents. However, with the advent of drug-eluting stents (DES), the long-term outcomes of PCI with DES to treat unprotected LMCA stenoses have been reported to be acceptable. Therefore, apart from the current guidelines, PCI for unprotected LMCA stenosis in many countries is often undertaken in individuals who are at very high risk of CABG or refuse to undergo a sternotomy. Future randomized studies comparing CABG versus PCI using DES for treatment of unprotected LMCA stenosis would be a great advance in the clinical knowledge of adopting appropriate treatments.     

Percutaneous coronary intervention as an alternative to bypass surgery for unprotected LMCA stenosis

Hemodynamically significant left main coronary artery (LMCA) stenosis is found in approximately 4% of diagnostic coronary angiograms and is known as unprotected LMCA stenosis if the left coronary artery and left circumflex artery have no patent previous grafts. Previous randomized studies have demonstrated a significant reduction in mortality when revascularization by coronary artery bypass graft (CABG) surgery was undertaken compared with medical treatment. Therefore, current practice guidelines do not recommend percutaneous coronary intervention (PCI) for such a lesion, owing to the proven benefit of surgery and high rates of restenosis with the use of bare metal stents. However, with the advent of drug-eluting stents (DES), the long-term outcomes of PCI with DES to treat unprotected LMCA stenoses have been reported to be acceptable. Therefore, apart from the current guidelines, PCI for unprotected LMCA stenosis in many countries is often undertaken in individuals who are at very high risk of CABG or refuse to undergo a sternotomy. Future randomized studies comparing CABG versus PCI using DES for treatment of unprotected LMCA stenosis would be a great advance in the clinical knowledge of adopting appropriate treatments.     

冠状动脉介入治疗时代孤立性左主干狭窄病变患者的临床特征和预后分析

目的 回顾性分析孤立性左主干(left main coronary artery,LMCA)狭窄病变患者的临床特征和预后.方法 连续入选30例孤立性LMCA狭窄病变患者并分为两组:开口病变组(n=21)和非开口病变组(n=9).随访终点为主要心脑血管不良事件(major adverse cardiac or cereb...     

Comparative cost-effectiveness analyses of cardiovascular magnetic resonance and coronary angiography combined with fractional flow reserve for the diagnosis of coronary artery disease

Abstracts

Background

According to recent guidelines, patients with coronary artery disease (CAD) should undergo revascularization if significant myocardial ischemia is present. Both, cardiovascular magnetic resonance (CMR) and fractional flow reserve (FFR) allow for a reliable ischemia assessment and in combination with anatomical information provided by invasive coronary angiography (CXA), such a work-up sets the basis for a decision to revascularize or not. The cost-effectiveness ratio of these two strategies is compared.

Methods

Strategy 1) CMR to assess ischemia followed by CXA in ischemia-positive patients (CMR + CXA), Strategy 2) CXA followed by FFR in angiographically positive stenoses (CXA + FFR). The costs, evaluated from the third party payer perspective in Switzerland, Germany, the United Kingdom (UK), and the United States (US), included public prices of the different outpatient procedures and costs induced by procedural complications and by diagnostic errors. The effectiveness criterion was the correct identification of hemodynamically significant coronary lesion(s) (= significant CAD) complemented by full anatomical information. Test performances were derived from the published literature. Cost-effectiveness ratios for both strategies were compared for hypothetical cohorts with different pretest likelihood of significant CAD.

Results

CMR + CXA and CXA + FFR were equally cost-effective at a pretest likelihood of CAD of 62% in Switzerland, 65% in Germany, 83% in the UK, and 82% in the US with costs of CHF 5′794, € 1′517, £ 2′680, and $ 2′179 per patient correctly diagnosed. Below these thresholds, CMR + CXA showed lower costs per patient correctly diagnosed than CXA + FFR.

Conclusions

The CMR + CXA strategy is more cost-effective than CXA + FFR below a CAD prevalence of 62%, 65%, 83%, and 82% for the Swiss, the German, the UK, and the US health care systems, respectively. These findings may help to optimize resource utilization in the diagnosis of CAD.     

Qualitative angiographic and quantitative myocardial perfusion assessment using fluorescent cardiac imaging during graded coronary artery bypass stenosis

Intraoperative graft assessment in coronary artery bypass (CAB) grafting is important to avoid early graft failure. This study aimed to evaluate the accuracy of fluorescent cardiac imaging (FCI) for intraoperative qualitative angiographic and quantitative myocardial perfusion assessment during graded CAB stenosis compared to coronary angiography (CA). After CAB grafting to the left anterior descending coronary artery, graded distal bypass stenoses were created in ten pigs by 25, 50, 75, and 100% flow reduction assessed by transit-time flow measurement (TTFM). Visual angiographic assessment was performed by FCI and CA during baseline and graded bypass stenoses. Altered myocardial perfusion was assessed by quantitative intraoperative fluorescence intensity (QIFI) derived from FCI and correlated to TTFM. Patent bypass grafts and graft occlusion were visualized successfully by FCI and CA, while discrimination between various graded bypass stenosis was possible in 73.3%. The degree of CAB stenosis was overestimated in 16.7% and underestimated in 10.0% by FCI compared to CA. Graded CAB stenosis reduced regional myocardial perfusion quantified by decreased QIFI value (p?<?0.001). Mean QIFI value was 76.8 (95% CI 67.2–86.3) during baseline, 55.6 (95% CI 45.3–65.9) during 25% flow-reduction, 30.6 (95% CI 22.3–39.0) during 50% flow-reduction, 20.3 (95% CI 15.4–25.3) during 75% flow-reduction, and 0 during CAB occlusion (p?<?0.001) with a significant correlation to TTFM (r?=?0.955; p?<?0.0001). Solely visual assessment of CAB quality using FCI is limited as compared to CA. Additional QIFI assessment identified graded CAB stenosis and occlusion with a significant correlation to TTFM.     

Reproducibility of coronary atherosclerotic plaque characteristics in populations with low,intermediate, and high prevalence of coronary artery disease by multidetector computer tomography: a guide to reliable visual coronary plaque assessments

To evaluate the interobserver agreement of visual coronary plaque characteristics by 320-slice multidetector computed tomography (MDCT) in three populations with low, intermediate and high CAD prevalence and to identify determinants for the reproducible assessment of these plaque characteristics. 150 patients, 50 asymptomatic subjects from the general population (low CAD prevalence), 50 symptomatic non-acute coronary syndrome (non-ACS) patients (intermediate CAD prevalence), and 50 ACS patients (high CAD prevalence), matched according to age and gender, were retrospectively enrolled. All coronary segments were evaluated for overall image quality, evaluability, presence of CAD, coronary stenosis, plaque composition, plaque focality, and spotty calcification by four readers. Interobserver agreement was assessed using Fleiss’ Kappa (κ) and intra-class correlation (ICC). Widely used clinical parameters (overall scan quality, presence of CAD, and determination of coronary stenosis) showed good agreement among the four readers, (ICC?=?0.66, κ?=?0.73, ICC?=?0.74, respectively). When accounting for heart rate, body mass index, plaque location, and coronary stenosis above/below 50?%, interobserver agreement for plaque composition, presence of CAD, and coronary stenosis improved to either good or excellent, (κ?=?0.61, κ?=?0.81, ICC?=?0.78, respectively). Spotty calcification was the least reproducible parameter investigated (κ?=?0.33). Across subpopulations, reproducibility of coronary plaque characteristics generally decreased with increasing CAD prevalence except for plaque composition, (limits of agreement: ±2.03, ±1.96, ±1.79 for low, intermediate and high CAD prevalence, respectively). 320-slice MDCT can be used to assess coronary plaque characteristics, except for spotty calcification. Reproducibility estimates are influenced by heart rate, body size, plaque location, and degree of luminal stenosis.     

Myocardial first pass perfusion assessed by cardiac magnetic resonance and coronary microvascular dysfunction in women with angina and no obstructive coronary artery disease

Coronary microvascular dysfunction (CMD) is associated with a poor prognosis even in absence of obstructive coronary artery disease. CMD can be assessed as a myocardial blood flow reserve by positron emission tomography (PETMBFR) and as coronary flow velocity reserve by transthoracic Doppler echocardiography (TTDECFVR). Impaired first-pass perfusion assessed by cardiac magnetic resonance (CMR) is an early sign of ischemia. We aimed to investigate the association between CMD and CMR first-pass perfusion. Women (n?=?66) with angina pectoris and an invasive coronary angiogram (<50% stenosis) were assessed by TTDECFVR and in a subgroup of these (n?=?54) also by PETMBFR. Semi-quantitative evaluation of first-pass perfusion at rest and adenosine stress was assessed by gadolinium CMR in all 66 women. Four measures of CMR perfusion reserve were calculated using contrast upslope, maximal signal intensity and both indexed to arterial input. Mean (standard deviation) age was 62 (8) years. Median (interquartile range) TTDECFVR was 2.3 (1.8;2.7) and PETMBFR was 2.7 (2.2;3.1). Using a cut-off of 2.0 for TTDECFVR and 2.5 for PETMBFR, 25 (38%) and 21 (39%) had CMD, respectively. CMR myocardial perfusion reserve from contrast upslope (CMR_MPRupslope) showed moderate but significant correlation with PETMBFR (R?=?.46, p?<?.001) while none of the other CMR variables were associated with CMD. A CMR_MPRupslope cut-off of 0.78 identified CMD, area under the curve 0.73 (p?=?.001). The results indicate that CMR_MPRupslope may be associated to PETMBFR; a measure of CMD. Further research is needed to validate and implement the use of CMR first pass perfusion in this population.     

Left main or proximal left anterior descending coronary artery disease: detection by echocardiographic evaluation of interventricular septal function during exercise

Summary. Forty patients with coronary artery disease were studied prospectively to investigate whether stenosis of the left main (LMCA) or left anterior descending coronary artery, proximal to the first septal branch (proximal LAD), could be detected by M-mode echocardiography during exertion. The interventricular septum was visualized in 30 of the patients during bicycle exercise in the semisupine position, all with simultaneous occurrence of electrocardiographic evidence of myocardial ischaemia. Fifteen of these had LMCA or proximal LAD stenosis. Systolic motion and thickening of the septum decreased significantly from rest to peak exercise in patients with LMCA or proximal LAD disease while it increased in those without. The results suggest that M-mode echocardiography during exercise in patients with coronary artery disease might identify those with LMCA or proximal LAD stenosis.     

Noise reduction technology reduces radiation dose in chronic total occlusions percutaneous coronary intervention: a propensity score-matched analysis

Chronic total occlusions (CTO) percutaneous coronary intervention (PCI) is associated with high radiation dose. Our study aim was to evaluate the impact of the implementation of a noise reduction technology (NRT) on patient radiation dose during CTO PCI. A total of 187 CTO PCIs performed between February 2016 and May 2017 were analyzed according to the angiographic systems utilized: Standard (n?=?60) versus NRT (n?=?127). Propensity score matching (PSM) was performed to control for differences in baseline characteristics. Primary endpoints were Cumulative Air Kerma at Interventional Reference Point (AK at IRP), which correlates with patient’s tissue reactions; and Kerma Area Product (KAP), a surrogate measure of patient’s risk of stochastic radiation effects. An Efficiency Index (defined as fluoroscopy time/AK at IRP) was calculated for each procedure. Image quality was evaluated using a 5-grade Likert-like scale. After PSM, n?=?55 pairs were identified. Baseline and angiographic characteristics were well matched between groups. Compared to the Standard system, NRT was associated with lower AK at IRP [2.38 (1.80–3.66) vs. 3.24 (2.04–5.09) Gy, p?=?0.035], a trend towards reduction for KAP [161 (93–244) vs. 203 (136–363) Gycm², p?=?0.069], and a better Efficiency Index [16.75 (12.73–26.27) vs. 13.58 (9.92–17.63) min/Gy, p?=?0.003]. Image quality was similar between the two groups (4.39?±?0.53 Standard vs. 4.34?±?0.47 NRT, p?=?0.571). In conclusion, compared with a Standard system, the use of NRT in CTO PCI is associated with lower patient radiation dose and similar image quality.     

Cost evaluation of cardiovascular magnetic resonance versus coronary angiography for the diagnostic work-up of coronary artery disease: Application of the European Cardiovascular Magnetic Resonance registry data to the German,United Kingdom,Swiss, and United States health care systems

Background

Cardiovascular magnetic resonance (CMR) has favorable characteristics for diagnostic evaluation and risk stratification of patients with known or suspected CAD. CMR utilization in CAD detection is growing fast. However, data on its cost-effectiveness are scarce. The goal of this study is to compare the costs of two strategies for detection of significant coronary artery stenoses in patients with suspected coronary artery disease (CAD): 1) Performing CMR first to assess myocardial ischemia and/or infarct scar before referring positive patients (defined as presence of ischemia and/or infarct scar to coronary angiography (CXA) versus 2) a hypothetical CXA performed in all patients as a single test to detect CAD.

Methods

A subgroup of the European CMR pilot registry was used including 2,717 consecutive patients who underwent stress-CMR. From these patients, 21% were positive for CAD (ischemia and/or infarct scar), 73% negative, and 6% uncertain and underwent additional testing. The diagnostic costs were evaluated using invoicing costs of each test performed. Costs analysis was performed from a health care payer perspective in German, United Kingdom, Swiss, and United States health care settings.

Results

In the public sectors of the German, United Kingdom, and Swiss health care systems, cost savings from the CMR-driven strategy were 50%, 25% and 23%, respectively, versus outpatient CXA. If CXA was carried out as an inpatient procedure, cost savings were 46%, 50% and 48%, respectively. In the United States context, cost savings were 51% when compared with inpatient CXA, but higher for CMR by 8% versus outpatient CXA.

Conclusion

This analysis suggests that from an economic perspective, the use of CMR should be encouraged as a management option for patients with suspected CAD.     

Fusion of CT coronary angiography and whole-heart dynamic 3D cardiac MR perfusion: building a framework for comprehensive cardiac imaging

The purpose of this work was to develop a framework for 3D fusion of CT coronary angiography (CTCA) and whole-heart dynamic 3D cardiac magnetic resonance perfusion (3D-CMR-Perf) image data—correlating coronary artery stenoses to stress-induced myocardial perfusion deficits for the assessment of coronary artery disease (CAD). Twenty-three patients who underwent CTCA and 3D-CMR-Perf for various indications were included retrospectively. For CTCA, image quality and coronary diameter stenoses >?50% were documented. For 3D-CMR-Perf, image quality and stress-induced perfusion deficits were noted. A software framework was developed to allow for 3D image fusion of both datasets. Computation steps included: (1) fully automated segmentation of coronary arteries and heart contours from CT; (2) manual segmentation of the left ventricle in 3D-CMR-Perf images; (3) semi-automatic co-registration of CT/CMR datasets; (4) projection of the 3D-CMR-Perf values on the CT left ventricle. 3D fusion analysis was compared to separate inspection of CTCA and 3D-CMR-Perf data. CT and CMR scans resulted in an image quality being rated as good to excellent (mean scores 3.5?±?0.5 and 3.7?±?0.4, respectively, scale 1–4). 3D-fusion was feasible in all 23 patients, and perfusion deficits could be correlated to culprit coronary lesions in all but one case (22/23?=?96%). Compared to separate analysis of CT and CMR data, coronary supply territories of 3D-CMR-Perf perfusion deficits were refined in two cases (2/23?=?9%), and the relevance of stenoses in CTCA was re-judged in four cases (4/23?=?17%). In conclusion, 3D fusion of CTCA/3D-CMR-Perf facilitates anatomic correlation of coronary lesions and stress-induced myocardial perfusion deficits thereby helping to refine diagnostic assessment of CAD.     

A comparison of quantitative computerized and human panel coronary endpoint measures: Implications for the design of angiographic trials

The Monitored Atherosclerosis Regression Study was a double-blind, 2-year, placebo-controlled, randomized, serial angiographic trial which tested reduction of low density lipoprotein-cholesterol with monotherapy using lovastatin on the progression of coronary atherosclerosis. Angiographic outcome was evaluated both by a panel of human readers who visually inspected matched film pairs to arrive at a global change score and by automated computerized vessel edge finding and lesion measurement (quantitative coronary angiography, QCA). In this paper, we model the association between QCA measures of coronary artery lesion change and the panel-based global change score. QCA measures included: per-patient changes in percent diameter stenosis and minimum lumen diameter averaged over all lesions; per-patient changes in average diameter and percent involvement averaged over all segments; the numbers of progressing and regressing lesions and new total occlusions; and the development of any new lesions.We found that when evaluating coronary artery lesion change, panelists evaluate changes in percent diameter stenosis for both low grade (<50% diameter stenosis at baseline) and high grade (≥50% diameter stenosis at baseline) lesions as well as new total occlusions and the number of progressing lesions. Although computerized quantification of the size of a lesion at baseline and as an endpoint may be a more precise measure than that by human panel interpretation, QCA fails to incorporate many other important aspects of coronary angiographic change visualized over the entire coronary artery tree by a panel of human interpreters. Thus, the global change score provides a “multiple endpoint” for coronary angiographic trials which does not suffer from the problems of statistical analysis and interpretation of multiple hypothesis tests which usually accompany true multiple endpoint measures. Choice of either or both endpoints in preparing angiographic trials depends on careful consideration of the desired information as well as the cost of carrying out the endpoint analysis.     

Magnetic resonance evaluation of the associations of thoracic and abdominal aortic plaques with the presence and extent of coronary artery stenosis.

The association between coronary artery disease (CAD) and thoracic aortic plaques has often been reported using transesophageal echocardiography. However, studies showing the association between CAD and abdominal aortic plaques are scarce. CMR can visualize plaques in both the thoracic and abdominal aortas. Using CMR, we investigated the associations of thoracic and abdominal aortic plaques with the presence and extent of coronary artery stenosis in 146 patients undergoing coronary angiography, of whom 108 had CAD. The prevalence of thoracic and abdominal aortic plaques was higher in patients with CAD than in those without CAD (73% and 94% vs. 32% and 79%, p < 0.025). Stepwise increases in the prevalence and extents of both thoracic and abdominal plaques were found depending on the number of stenotic coronary vessels. Plaque extent in the thoracic aorta correlated with the numbers of > 50% and > 25% stenotic coronary segments (rs = 0.30 and 0.41). Plaque extent in the abdominal aorta also correlated with the numbers of > 50% and > 25% stenotic segments (rs = 0.40 and 0.44). Notably, the total plaque extent in the aortas correlated best with the numbers of > 50% and > 25% stenotic coronary segments (rs = 0.41 and 0.49, p < 0.001), and this factor was found to be the best predictor for the presence of CAD by the receiver-operating-characteristics curve analysis. Thus, the total plaque extent in the aortas was found to be more closely associated with the presence and extent of coronary stenosis than the thoracic or abdominal aortic plaque extent.     

Potential intrinsic error of noninvasive coronary angiography.

PURPOSE: With current noninvasive techniques compromises have to be accepted for coronary imaging, e.g., partial coverage of the coronary artery tree. The aim of the study was to estimate the potential intrinsic error of partial coverage from a database of invasive angiograms. METHODS AND RESULTS: The localization and severity of coronary artery stenoses and, if percutaneous coronary intervention (PCI) was performed, the balloon and stent size were extracted from a large database of 21,335 selective coronary angiograms. Of stenoses with >50% diameter reduction, 31.4% were located in distal segments and minor side branches, constituting 28.8% of interventional treatment. In 5% of patients undergoing their first invasive angiogram, the most proximal relevant stenosis was found in a distal segment or minor side branch. Most interventions (83.5%) were performed in main coronary artery segments. CONCLUSION: Coronary artery stenoses were found and interventional treatment performed in all coronary segments. Therefore, noninvasive coronary imaging of only proximal and medial segments and major side branches is an inadequate strategy for complete diagnosis or as a guide to therapeutic decisions. However, the currently available noninvasive techniques allow the detection of relevant stenoses in 95% of patients with suspected coronary artery disease (CAD) to prepare for further invasive diagnostic and therapeutic planning.     

Characteristics of coronary plaques before angiographic progression determined by Multi-Slice CT

The aim of the present study was to characterize coronary plaques by Multi-Slice Computed Tomography (Siemens sensation 16, Forcheim, Germany) before significant angiographic progression occurred and to compare them to non-progressing lesions. The MSCT-morphology of coronary plaques leading to a rapid angiographic disease progression is not yet studied. In a series of 68 patients who were scheduled for surveillance angiography 6 months later, MSCT-angiography was done shortly after the baseline catheterisation-procedure. After surveillance angiography rapid progressive lesions with an increase of the stenosis severity of >20% were identified and analysed on the baseline MSCT-scan and were compared to non-progressing lesions. Six months after coronary stenting we observed significant progression of de novo stenoses in 10/438 coronary segments. The progression of four lesions lead to angina pectoris symptoms and the remaining six lesions progressed silently. Analysis of the lesion morphology by MSCT revealed that 5/10 (50%) progressing lesions were non-calcified 3/10 (30%) were predominantly non-calcified and 2/10 (20%) were mainly calcified on the baseline MSCT-scan. In the 428 segments without disease progression atherosclerotic lesions were found in 225 segments on MSCT. Non-calcified plaques were identified in 46 (20%), predominantly non-calcified lesions in 58 (26%) and predominantly calcified lesions in 121 (54%) segments. The average number of diseased coronary segments between patients with and without lesion progression was not significantly different between progressors and non-progressors with a higher prevalence of non-calcified segments in the progressor group (1.1 vs. 0.63). Rapid progression of the angiographic stenosis severity during a 6 months period occurs most frequently in coronary segments revealing non-calcified or predominantly non-calcified plaques as determined by MSCT, whereas lesion progression is rare in predominantly calcified segments. This represents first evidence that non-calcified lesions may be involved in the process of plaque rupture.