Association of serum MMP9 with adverse features of plaque progression in patients with chronic coronary syndrome (CCS)

Background

Previous studies have demonstrated that MMP-9 may be a predictor of atherosclerotic plaque instability and future adverse cardiovascular events, but longitudinal data on the association between MMP9 and coronary disease progression are lacking.

Purpose

This study is aimed at investigating whether MMP9 is associated with atherosclerotic plaque progression.

Methods

MMP9 serum levels were measured in stable patients with chronic coronary syndrome (CCS) undergoing coronary computed tomography angiography at baseline and after a period of 6.5±1.1 years of follow up to assess progression of Total, Fibrous, Fibro-fatty, Necrotic Core, and Dense Calcium plaque volume (PV). The relationship of serum MMP9 with plaque progression was assessed using linear regression analysis, adjusting for clinical variables including, age, sex, risk factors, medical therapy, LDL-C, TG/HDL-C ratio, hs-CRP, and the presence of obstructive CAD (>50% coronary stenosis in at least one major coronary vessels).

Results

A total of 157 patients (58±8 years of age; 66% males) were included in the analysis, with median MMP9 values of 135±186 mg/dL (mean ± SD). Annual changes of Total, Fibrous-Fatty and Necrotic Core PV were significantly different across MMP9 tertiles (Figure 1). Multivariable linear regression analysis demonstrated a positive association between serum levels of MMP9 and annual change of Total and Necrotic Core PV (Figure 1).

Conclusion

Among patients with CCS, MMP9 serum levels were an independent predictor of progression of coronary plaque burden and, in particular, of adverse plaque features, such as Necrotic Core PV. This association was robust and independent from baseline traditional cardiovascular risk factors and medications, supporting for MMP9 a role as a novel marker of residual coronary risk.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): Horizon 2020 - Project “Simulation Modeling of coronary ARTery disease: a tool for clinical decision support–SMARTool”

Radiomics-based analysis by machine learning techniques improves characterization of functionally significant coronary lesions

Background

Computed Tomography Coronary Angiography (CTCA) is an effective non-invasive imaging modality for anatomo-functional assessment of coronary artery disease (CAD). Radiomics features have been used for diagnosis or outcome prediction, however, their potential value for characterizing flow limiting coronary lesions has not been explored.

Purpose

To assess whether application of novel radiomics and machine learning (ML) techniques on CTCA derived datasets improves characterization of functionally significant coronary lesions.

Methods

Consecutive patients with stable chest pain and intermediate pre-test likelihood for CAD, who underwent CTCA and PET-or SPECT-Myocardial Perfusion Imaging (MPI) respectively, were prospectively evaluated and included in the analysis. PET-MPI was considered abnormal when >1 contiguous segments showed both stress Myocardial Blood Flow ≤2.3mL/g/min and Myocardial Flow Reserve (MFR) ≤2.5 for 15O-water or <1.79 mL/g/min and ≤2.0 for 13N-ammonia respectively. Defect reversibility (DR) was defined as a summed difference score (SDS) between stress and rest images ≥2. CTCA and functional images were fused to assign each myocardial segment to the pertinent coronary territory. Stenosis severity, plaque characteristics and radiomic plaque features were assessed in the total length of the 3 main coronary vessels. In total, 1765 features were extracted from each vessel and a feature reduction and model creation pipeline was constructed [Figure 1]. Two separate datasets: a) coronary stenosis (≥50%) + plaque characteristics and b) coronary stenosis (≥50%) + plaque characteristics + radiomics were formulated and compared in terms of AUCs accordingly.

Results

A total of 292 coronary vessels (140 with corresponding PET-MPI data and 152 with SPECT MPI data) were analysed. Plaque burden and stenosis severity were the only independent predictors of impaired myocardial perfusion on PET-MPI, with an AUC = 0.749, (95% CI: 0.658–0.826). Stenosis severity, kurtosis, contrast, interquartile range and entropy were predictors of an abnormal PET-MPI result and their combination resulted in an AUC = 0.854, (95% CI: 0.775–0.914). The difference between the 2 models was statistically significant (p-diff: 0.02, 95% CI: 0.0165–0.194). Stenosis severity was the only predictor of a DR on SPECT-MPI, AUC = 0.624 (95% CI: 0.542–0.702). Small Dependence High Gray Level Emphasis, Cluster Prominence, Region Length, wavelet Median and square Median were predictors of a positive SPECT result, with AUC = 0.816, (95% CI: 0.745–0.875). The difference between the two models was statistically significant (p-diff: 0.006, 95% CI: 0.152–0.329)

Conclusion

Radiomic futures can be combined with anatomical and morphological characteristics of coronary lesions in CTCA imaging and provide valuable complementary information for characterizing functionally significant coronary lesions.

Funding Acknowledgement

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This work was supported from European Regional Development Fund, Operational Programme “Competitiveness, Entrepreneurship and Innovation 2014-2022 (EPAnEK)”, titled: The Greek Research Infrastructure for Personalized Medicine (pMED-GR)

Association of MMP9 with adverse features of plaque progression and residual inflammatory risk in patients with chronic coronary syndrome (CCS)

BACKGROUND AND AIMS

MMP-9 is a predictor of atherosclerotic plaque instability and adverse cardiovascular events, but longitudinal data on the association between MMP9 and coronary disease progression are lacking. This study is aimed at investigating whether MMP9 is associated with atherosclerotic plaque progression and the related molecular basis in stable patients with chronic coronary syndrome (CCS).

METHODS

MMP9 serum levels were measured in 157 CCS patients (58 ± 8 years of age; 66% male) undergoing coronary computed tomography angiography at baseline and after a follow up period of 6.5 ± 1.1 years to assess progression of Total, Fibrous, Fibro-fatty, Necrotic Core, and Dense Calcium plaque volumes (PV). Gene expression analysis was evaluated in whole blood using a transcriptomic approach by RNA-seq.

RESULTS

At multivariate analysis, serum MMP9 was associated with annual change of Total and Necrotic Core PV (Coefficient 3.205, SE 1.321, P = 0.017; 1.449, SE 0.690, P = 0.038, respectively), while MMP9 gene expression with Necrotic Core PV (Coefficient 70.559, SE 32.629, P = 0.034), independently from traditional cardiovascular risk factors, medications, and presence of obstructive CAD. After transcriptomic analysis, MMP9 expression was linked to expression of genes involved in the innate immunity.

CONCLUSIONS

Among CCS patients, MMP9 is an independent predictive marker of progression of adverse coronary plaques, possibly reflecting the activity of inflammatory pathways conditioning adverse plaque phenotypes. Thus, blood MMP9 might be used for the identification of patients with residual risk even with optimal management of classical cardiovascular risk factors who may derive the greatest benefit from targeted anti-inflammatory drugs.

Impact of COVID-19 Pandemic on Cardiovascular Testing in Asia

Background

The coronavirus disease-2019 (COVID-19) pandemic significantly affected management of cardiovascular disease around the world. The effect of the pandemic on volume of cardiovascular diagnostic procedures is not known.

Objectives

This study sought to evaluate the effects of the early phase of the COVID-19 pandemic on cardiovascular diagnostic procedures and safety practices in Asia.

Methods

The International Atomic Energy Agency conducted a worldwide survey to assess changes in cardiovascular procedure volume and safety practices caused by COVID-19. Testing volumes were reported for March 2020 and April 2020 and were compared to those from March 2019. Data from 180 centers across 33 Asian countries were grouped into 4 subregions for comparison.

Results

Procedure volumes decreased by 47% from March 2019 to March 2020, showing recovery from March 2020 to April 2020 in Eastern Asia, particularly in China. The majority of centers cancelled outpatient activities and increased time per study. Practice changes included implementing physical distancing and restricting visitors. Although COVID testing was not commonly performed, it was conducted in one-third of facilities in Eastern Asia. The most severe reductions in procedure volumes were observed in lower-income countries, where volumes decreased 81% from March 2019 to April 2020.

Conclusions

The COVID-19 pandemic in Asia caused significant reductions in cardiovascular diagnostic procedures, particularly in low-income countries. Further studies on effects of COVID-19 on cardiovascular outcomes and changes in care delivery are warranted.

Elevated triglycerides and low HDL cholesterol predict coronary heart disease risk in patients with stable angina

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): The EVINCI study was supported by a grant from the European Union FP7-CP-FP506 2007 project (GA 222915). The SMARTool study was supported by a grant from the European Union H2020-PHC-30-2015 (GA 689068). This study was also partially supported by a grant from AMGEN (Protocol N. 20167781, 2017).

Background. High triglycerides (TG) and low high-density lipoprotein cholesterol  (HDL-C) characterize an atherosclerotic cardiovascular disease (CAD) risk condition defined as atherogenic dyslipidemia.

Aim. To assess whether atherogenic dyslipidemia defined by TG/HDL-C ratio predicts CAD related outcomes in patients with stable angina, independently of other risk factors and treatments.

Methods. We studied 355 patients (60 ± 9 y, 211m) with stable angina from the EVINCI Outcome study. Patients were characterized for clinical, bio-humoral and imaging profiles, managed clinically, and followed for 4.5 ± 0.9 years. A computed tomography angiography (CTA) coronary risk score was obtained at baseline in all patients, and at follow-up in 154 of them. The primary composite outcome was all-cause mortality and non-fatal myocardial infarction. CTA scan was repeated at follow-up in 154 patients to assess CAD progression.

Results. The median value of TG/HDL-C ratio was 2.095 (2.079IQR). At baseline, the proportion of males, smoking, diabetes and metabolic syndrome, as well as circulating bio-markers of abnormal glucose metabolism and myocardial damage progressively increased across quartiles of TG/HDL-C ratio. The CTA score was significantly higher in the IV quartile of the TG/HDL-C ratio and both were the only independent predictors of the primary (CTA Score: HR 1.06, 95%CI 1.03-1.09, p = 0.001; TG/HDL-C IV quartile: HR 2.85, 95%CI 1.30-6.26, p < 0.01). In the 154 patients re-evaluated at follow-up, TG/HDL-C ratio associated cardio-metabolic disorder, systemic inflammation and CTA risk score progressed over time despite increased use of lipid-lowering drugs, anti-diabetics and other cardioactive medications and reduction in LDL-C levels.

Conclusions. In patients with stable angina, the TG/HDL-C ratio expresses a cardio-metabolic atherogenic disorder which is progressive over time and is associated with CAD related outcomes independently of LDL-C levels and treatments.

Prediction of impaired myocardial blood flow (MBF) with the use of machine learning techniques on CTCA based parameters

Funding Acknowledgements

Type of funding sources: Public grant(s) – EU funding. Main funding source(s): This work was supported in part from European Regional Development Fund, Operational Programme “Competitiveness, Entrepreneurship and Innovation 2014-2020 (EPAnEK)”, titled: The Greek Research Infrastructure for Personalized Medicine (pMED-GR) , no. GR 5002802 ,and by Greece and the European Union (European Social Fund-ESF) through the Operational Programme «Human Resources Development, Education and Lifelong Learning 2014-2020» in the context of the project “Assessment of coronary atherosclerosis: a new complete, anatomo-functional, morphological and biomechanical approach”, Project no. 504776

Background

Computed Tomography Coronary Angiography (CTCA) is a non-invasive imaging modality, used effectively for anatomo-functional assessment of coronary artery disease (CAD). Machine learning (ML) processes can effectively allow the extraction of useful information from multidimensional feature spaces for evaluation of coronary lesions.

Purpose

To investigate the ability of ML for predicting impaired myocardial blood flow (MBF) by combining computational fluid dynamics (CFD) derived parameters with quantitative plaque burden, plaque morphology and anatomical characteristics obtained from CTCA.

Methods

53 patients (31 male, mean age 64.7 ± 7.1 years) with intermediate pre-test likelihood of CAD who underwent CTCA and PET-MPI were included. PET was considered positive when > 1 contiguous segment demonstrated MBF ≤ 2.3 mL/g/min for 15O-water or ≤ 1.79 for 13N-ammonia respectively. CFD derived parameters such as a previously validated, virtual functional assessment index (vFAI), segmental endothelial shear stress (ESS), as well as anatomical and plaque characteristics were assessed. Seven classifiers were implemented and internally validated using 5-fold cross validation, repeated 1000 times. Using sequential forward selection (SFS), the highest rank features combination, based on appearances in the highest mean area under curve (AUC) classification scheme, was selected and features performance was evaluated following exhaustive search (ES).

Results

92 coronary segments were analyzed and 34 features derived from CTCA were extracted. Classifiers performance are depicted in Figure A. k-NN was the best classifier with AUCmean = 0.791 (SENSmean= 0.622, SPECmean = 0.840, p < 0.05). Clusters of features and number of appearances are presented in Figure B. The combination of vFAI, stenosis severity and lumen area demonstrated the highest AUC (1473 times). ES results are depicted in Figure C. The combination of vFAI and lumen area was the best predictor among all the combinations (AUCmean = 0.830, SENSmean =0.61, SPECmean =0.83, p < 0.05) followed by vFAI and stenosis severity (AUCmean = 0.81, SENSmean =0.72, SPECmean = 0.87, p < 0.05) and vFAI alone (AUCmean = 0.806, SENSmean =0.61, SPECmean =0.87, p < 0.05).

Conclusion

ML analysis is feasible for predicting with reasonable specificity abnormal MBF by PET, using a combination of CFD derived parameters and anatomical features. vFAI as a single characteristic was a specific predictor of impaired MBF, whilst in combination with stenosis severity, maintained almost the same AUC and specificity values and resulted in improved sensitivity. On the other hand, addition of lumen area to vFAI, increases the AUC and provides a relatively good specificity but low  sensitivity.

Abstract Figure 1

P6167Low leptin plasma levels are associated with progression of coronary atherosclerosis in patients with stable coronary artery disease from the SMARTool Study

Background

Leptin is an adipokine involved in energy homeostasis and has been related with established vascular risk factors. However, studies on the association of leptin plasma levels with coronary artery disease (CAD) have yielded conflicting results.

Purpose

Aim of the present study was to evaluate the association between leptin plasma levels and presence, severity and progression of coronary atherosclerosis in patients with suspected stable CAD.

Methods

In a cohort of 257 patients with symptoms of stable CAD enrolled in the SMARTool study, coronary computed tomography angiography (CTA), plasma leptin levels and clinical and bio-humoral CAD risk profile (including glucose, lipid and inflammation variables) were obtained at enrolment and after 6±1yrs of follow-up. Sixty-four patients were revascularized and the remaining 193 represent the population for the present study. CTA findings were categorised as no-minimal CAD (<30% stenosis), non-obstructive CAD (30%-50% stenosis) and obstructive CAD (≥50% stenosis in at least one major coronary vessel). A CTA risk score (based on plaque extent, severity, composition, and location) was calculated at baseline and at follow-up to assess coronary atherosclerotic burden and its progression (Δ CTA score≥5).

Results

CTA findings showed obstructive CAD in 11% of patients at baseline and in 15% at follow-up (p<0.0001). CTA risk score, was 8.03±7.80 at baseline and increased to 10.33±8.17 at follow-up (p<0.0001) with CAD progression in 20% of patients. Leptin plasma levels were inversely related with CTA findings both at baseline and follow-up (Figure). In a Cox model, baseline plasma leptin was an independent predictor of CAD progression, after adjustment for clinical risk factors, biomarkers, and treatment (HR 0.572, 95% CI 0.393–0.834, P=0.0037).

Figure 1

Conclusion

Plasma leptin is inversely associated with coronary atherosclerotic burden and disease progression in patients with stable CAD. This association is independent of known factors affecting leptin levels. These results could prompt further investigations on the pathophysiological mechanisms of this association.

Acknowledgement/Funding

EU H2020 research and innovation program under grant agreement No 689068

Diagnosis of obstructive coronary artery disease using computed tomography angiography in patients with stable chest pain depending on clinical probability and in clinically important subgroups: meta-analysis of individual patient data

OBJECTIVE

To determine whether coronary computed tomography angiography (CTA) should be performed in patients with any clinical probability of coronary artery disease (CAD), and whether the diagnostic performance differs between subgroups of patients.

DESIGN

Prospectively designed meta-analysis of individual patient data from prospective diagnostic accuracy studies.

DATA SOURCES

Medline, Embase, and Web of Science for published studies. Unpublished studies were identified via direct contact with participating investigators.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Prospective diagnostic accuracy studies that compared coronary CTA with coronary angiography as the reference standard, using at least a 50% diameter reduction as a cutoff value for obstructive CAD. All patients needed to have a clinical indication for coronary angiography due to suspected CAD, and both tests had to be performed in all patients. Results had to be provided using 2×2 or 3×2 cross tabulations for the comparison of CTA with coronary angiography. Primary outcomes were the positive and negative predictive values of CTA as a function of clinical pretest probability of obstructive CAD, analysed by a generalised linear mixed model; calculations were performed including and excluding non-diagnostic CTA results. The no-treat/treat threshold model was used to determine the range of appropriate pretest probabilities for CTA. The threshold model was based on obtained post-test probabilities of less than 15% in case of negative CTA and above 50% in case of positive CTA. Sex, angina pectoris type, age, and number of computed tomography detector rows were used as clinical variables to analyse the diagnostic performance in relevant subgroups.

RESULTS

Individual patient data from 5332 patients from 65 prospective diagnostic accuracy studies were retrieved. For a pretest probability range of 7-67%, the treat threshold of more than 50% and the no-treat threshold of less than 15% post-test probability were obtained using CTA. At a pretest probability of 7%, the positive predictive value of CTA was 50.9% (95% confidence interval 43.3% to 57.7%) and the negative predictive value of CTA was 97.8% (96.4% to 98.7%); corresponding values at a pretest probability of 67% were 82.7% (78.3% to 86.2%) and 85.0% (80.2% to 88.9%), respectively. The overall sensitivity of CTA was 95.2% (92.6% to 96.9%) and the specificity was 79.2% (74.9% to 82.9%). CTA using more than 64 detector rows was associated with a higher empirical sensitivity than CTA using up to 64 rows (93.4% v 86.5%, P=0.002) and specificity (84.4% v 72.6%, P<0.001). The area under the receiver-operating-characteristic curve for CTA was 0.897 (0.889 to 0.906), and the diagnostic performance of CTA was slightly lower in women than in with men (area under the curve 0.874 (0.858 to 0.890) v 0.907 (0.897 to 0.916), P<0.001). The diagnostic performance of CTA was slightly lower in patients older than 75 (0.864 (0.834 to 0.894), P=0.018 v all other age groups) and was not significantly influenced by angina pectoris type (typical angina 0.895 (0.873 to 0.917), atypical angina 0.898 (0.884 to 0.913), non-anginal chest pain 0.884 (0.870 to 0.899), other chest discomfort 0.915 (0.897 to 0.934)).

CONCLUSIONS

In a no-treat/treat threshold model, the diagnosis of obstructive CAD using coronary CTA in patients with stable chest pain was most accurate when the clinical pretest probability was between 7% and 67%. Performance of CTA was not influenced by the angina pectoris type and was slightly higher in men and lower in older patients.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42012002780.

Correction to: Applicability and accuracy of pretest probability calculations implemented in the NICE clinical guideline for decision making about imaging in patients with chest pain of recent onset

The original version of this article, published on 19 March 2018, unfortunately contained a mistake. The following correction has therefore been made in the original: The names of the authors Philipp A. Kaufmann, Ronny Ralf Buechel and Bernhard A. Herzog were presented incorrectly.

Applicability and accuracy of pretest probability calculations implemented in the NICE clinical guideline for decision making about imaging in patients with chest pain of recent onset

OBJECTIVES

To analyse the implementation, applicability and accuracy of the pretest probability calculation provided by NICE clinical guideline 95 for decision making about imaging in patients with chest pain of recent onset.

METHODS

The definitions for pretest probability calculation in the original Duke clinical score and the NICE guideline were compared. We also calculated the agreement and disagreement in pretest probability and the resulting imaging and management groups based on individual patient data from the Collaborative Meta-Analysis of Cardiac CT (CoMe-CCT).

RESULTS

4,673 individual patient data from the CoMe-CCT Consortium were analysed. Major differences in definitions in the Duke clinical score and NICE guideline were found for the predictors age and number of risk factors. Pretest probability calculation using guideline criteria was only possible for 30.8 % (1,439/4,673) of patients despite availability of all required data due to ambiguity in guideline definitions for risk factors and age groups. Agreement regarding patient management groups was found in only 70 % (366/523) of patients in whom pretest probability calculation was possible according to both models.

CONCLUSIONS

Our results suggest that pretest probability calculation for clinical decision making about cardiac imaging as implemented in the NICE clinical guideline for patients has relevant limitations.

KEY POINTS

• Duke clinical score is not implemented correctly in NICE guideline 95. • Pretest probability assessment in NICE guideline 95 is impossible for most patients. • Improved clinical decision making requires accurate pretest probability calculation. • These refinements are essential for appropriate use of cardiac CT.

A New Integrated Clinical-Biohumoral Model to Predict Functionally Significant Coronary Artery Disease in Patients With Chronic Chest Pain

BACKGROUND

In patients with chronic angina-like chest pain, the probability of coronary artery disease (CAD) is estimated by symptoms, age, and sex according to the Genders clinical model. We investigated the incremental value of circulating biomarkers over the Genders model to predict functionally significant CAD in patients with chronic chest pain.

METHODS

In 527 patients (60.4 years, standard deviation, 8.9 years; 61.3% male participants) enrolled in the European Evaluation of Integrated Cardiac Imaging (EVINCI) study, clinical and biohumoral data were collected.

RESULTS

Functionally significant CAD-ie, obstructive coronary disease seen at invasive angiography causing myocardial ischemia at stress imaging or associated with reduced fractional flow reserve (FFR < 0.8), or both-was present in 15.2% of patients. High-density lipoprotein (HDL) cholesterol, aspartate aminotransferase (AST) levels, and high-sensitivity C-reactive protein (hs-CRP) were the only independent predictors of disease among 31 biomarkers analyzed. The model integrating these biohumoral markers with clinical variables outperformed the Genders model by receiver operating characteristic curve (ROC) (area under the curve [AUC], 0.70 [standard error (SE), 0.03] vs 0.58 [SE, 0.03], respectively, P < 0.001) and reclassification analysis (net reclassification improvement, 0.15 [SE, 0.07]; P = 0.04). Cross-validation of the ROC analysis confirmed the discrimination ability of the new model (AUC, 0.66). As many as 56% of patients who were assigned to a higher pretest probability by the Genders model were correctly reassigned to a low probability class (< 15%) by the new integrated model.

CONCLUSIONS

The Genders model has a low accuracy for predicting functionally significant CAD. A new model integrating HDL cholesterol, AST, and hs-CRP levels with common clinical variables has a higher predictive accuracy for functionally significant CAD and allows the reclassification of patients from an intermediate/high to a low pretest likelihood of CAD.

Direct coronary stent implantation does not reduce the incidence of in-stent restenosis or major adverse cardiac events: six month results of a randomized trial

STUDY OBJECTIVE

To compare the long-term angiographic, clinical and economic outcome of direct stenting vs stenting after balloon predilatation.

PATIENT POPULATION AND METHODS

Four hundred patients with coronary stenoses in a single native vessel were randomized to direct stenting vs stenting after predilatation. A major adverse cardiac and cerebral event (MACCE) was defined as death, myocardial infarction, stent thrombosis, target restenosis, repeat target- and non-target vessel-related percutaneous coronary intervention, target lesion revascularization, coronary artery bypass surgery and stroke.

RESULTS

Stents were successfully implanted in 98.3% of patients randomized to direct stenting vs 97.8% randomized to stenting preceded by predilatation. The primary success rate of direct stenting was 88.3%, vs 97.8% for stenting preceded by balloon dilatation (P=0.01). The angiographic follow-up at 6 months included 333 of the 400 patients (83%). The binary in-stent restenosis rate was 23.1% of 163 patients randomized to direct stenting vs 18.8% of 166 patients randomized to balloon predilatation (P=0.32). By 185+/-25 days, MACCE had occurred in 31 of 200 (15.5%) patients randomized to direct stenting, vs 33 of 200 (16.5%) randomized to predilatation (P=0.89). At 6 months, costs associated with the direct stenting strategy (Euros 3222/patient) were similar to those associated with predilatation (Euros 3428/patient, P=0.43). However, procedural costs were significantly lower. It is noteworthy that, on multivariate analysis, a baseline C-reactive protein level >10 mg l(-1)was a predictor of restenosis (odds ratio: 2.10, P=0.025) as well as of MACCE (odds ratio: 1.94, P=0.045).

CONCLUSIONS

Compared to stenting preceded by balloon predilatation, direct stenting was associated with similar 6-month restenosis and MACCE rates. Procedural, but not overall 6-month costs, were reduced by direct stenting. An increased baseline CRP level was an independent predictor of adverse long-term outcome after coronary stent implantation.

Early and late allergic reaction in the nose assessed by whole body plethysmography

Physiological changes during late phase nasal responses after allergen challenge are difficult to establish and different criteria are used for the definition of a positive late phase nasal reaction. The objective of this study was to assess the value of whole body plethysmography in detecting changes in nasal airway resistance after allergen challenge and to suggest criteria for the definition of early and late phase nasal reactions. Nasal challenge with allergen was performed in 15 allergic patients. Nasal resistance was followed until 10 h after allergen challenge and on a control day using whole body plethysmography. The mean percentage changes in the inspiratory nasal resistance during the early phase period (0.25-2 h) and the late phase period (4-10 h) were significantly higher on the allergen challenge day than on the control day (p=0.001 and p=0.01, respectively). The mean percentage change in the inspiratory nasal resistance during the early and late phase period on the control day plus 2 times the standard deviation served as cut-off point for a positive reaction. Using this definition, all patients had early reactions and 7 of the 15 patients (47%) also had late reactions. We conclude that whole body plethysmography is a useful, noninvasive method for the measurement of the physiological changes in the nose following allergen challenge.

Vessel wall changes in the proximal non-treated segment after PTCA. An in vivo intracoronary ultrasound study

Intimal disruption is known to induce prolonged intimal functional disturbance and is thought to be one of the mechanisms contributing to restenosis after PTCA. Although such damage can be induced by minimal trauma, the inevitable far greater disruption caused by passage of the PTCA apparatus through the stenosis does not appear to induce significant angiographically documented intimal proliferation. Pathological studies, however, have suggested that such a process might occur. Intravascular ultrasound allows in vivo study of vessel wall shape and constitution and is a far more sensitive detector of coronary atheroma than angiography. In this study we sought to determine the frequency of such functional disturbances and to assess their significance with respect to restenosis. The study group comprised 18 patients who underwent IVUS examination immediately after PTCA and at 6-months follow-up. They were analysed for luminal dimensions and vessel wall changes at the site of PTCA and at the level of the proximal non-treated segment. Seven patients (38%) had restenosed at follow-up IVUS examination; two patients had angiographically demonstrated luminal narrowing proximal to the PTCA site whereas seven had new intimal thickening in the proximal non-treated segment demonstrated by IVUS. Six patients had no intimal changes in either PTCA treated or untreated segments. Proximal intimal thickening was seen more frequently in those in whom increased intimal thickening at the PTCA site was noted. A trend (P < 0.1) was found towards an increased rate of new proximal vessel disease in those patients who had angiographically restenosed. IVUS demonstrates new intimal thickening in proximal non-treated segments in a considerable number of or patients undergoing PTCA.(ABSTRACT TRUNCATED AT 250 WORDS)

Spontaneous plaque rupture visualized by intravascular ultrasound

An intravascular ultrasound examination was performed in order to evaluate an angiographically complicated lesion. Intravascular ultrasound was able to demonstrate spontaneous plaque rupture in a patient with recent acute subendocardial infarction. The inconclusive angiographic appearance was clarified by the intravascular examination and led us to conclude that the myocardial infarction was due to plaque rupture with subsequent thrombotic occlusion, which had spontaneously resolved by the time of the study.