Coronary heart disease classification using deep learning approach with feature selection for improved accuracy

BACKGROUND

Coronary heart disease (CHD) is one of the deadliest diseases and a risk prediction model for cardiovascular conditions is needed. Due to the huge number of features that lead to heart problems, it is often difficult for an expert to evaluate these huge features into account. So, there is a need of appropriate feature selection for the given CHD dataset. For early CHD detection, deep learning modes (DL) show promising results in the existing studies.

OBJECTIVE

This study aimed to develop a deep convolution neural network (CNN) model for classification with a selected number of efficient features using the LASSO (least absolute shrinkage and selection operator) technique. Also, aims to compare the model with similar studies and analyze the performance of the proposed model using accuracy measures.

METHODS

The CHD dataset of NHANES (National Health and Nutritional Examination Survey) was examined with 49 features using LASSO technique. This research work is an attempt to apply an improved CNN model for the classification of the CHD dataset with huge features CNN model with feature extractor consists of a fully connected layer with two convolution 1D layers, and classifier part consists of two fully connected layers with SoftMax function was trained on this dataset. Metrics like accuracy recall, specificity, and ROC were used for the evaluation of the proposed model.

RESULTS

The feature selection was performed by applying the LASSO model. The proposed CNN model achieved 99.36% accuracy, while previous studies model achieved over 80 to 92% accuracy.

CONCLUSION

The application of the proposed CNN with the LASSO model for the classification of CHD can speed up the diagnosis of CHD and appears to be effective in predicting cardiovascular disease based on risk features.

Non-invasive characterization of complex coronary lesions

Conventional invasive diagnostic imaging techniques do not adequately resolve complex Type B and C coronary lesions, which present unique challenges, require personalized treatment and result in worsened patient outcomes. These lesions are often excluded from large-scale non-invasive clinical trials and there does not exist a validated approach to characterize hemodynamic quantities and guide percutaneous intervention for such lesions. This work identifies key biomarkers that differentiate complex Type B and C lesions from simple Type A lesions by introducing and validating a coronary angiography-based computational fluid dynamic (CFD-CA) framework for intracoronary assessment in complex lesions at ultrahigh resolution. Among 14 patients selected in this study, 7 patients with Type B and C lesions were included in the complex lesion group including ostial, bifurcation, serial lesions and lesion where flow was supplied by collateral bed. Simple lesion group included 7 patients with lesions that were discrete, [Formula: see text] long and readily accessible. Intracoronary assessment was performed using CFD-CA framework and validated by comparing to clinically measured pressure-based index, such as FFR. Local pressure, endothelial shear stress (ESS) and velocity profiles were derived for all patients. We validates the accuracy of our CFD-CA framework and report excellent agreement with invasive measurements ([Formula: see text]). Ultra-high resolution achieved by the model enable physiological assessment in complex lesions and quantify hemodynamic metrics in all vessels up to 1mm in diameter. Importantly, we demonstrate that in contrast to traditional pressure-based metrics, there is a significant difference in the intracoronary hemodynamic forces, such as ESS, in complex lesions compared to simple lesions at both resting and hyperemic physiological states [n = 14, [Formula: see text]]. Higher ESS was observed in the complex lesion group ([Formula: see text] Pa) than in simple lesion group ([Formula: see text] Pa). Complex coronary lesions have higher ESS compared to simple lesions, such differential hemodynamic evaluation can provide much the needed insight into the increase in adverse outcomes for such patients and has incremental prognostic value over traditional pressure-based indices, such as FFR.

Classification of Patients with Coronary Microvascular Dysfunction

While coronary microvascular dysfunction (CMD) is a major cause of ischemia, it is very challenging to diagnose due to lack of CMD-specific screening measures. CMD has been identified as one of the five priority areas of investigation in a 2014 National Research Consensus Conference on Gender-Specific Research in Emergency Care. In this study, we utilized methods from machine learning that leverage structured and unstructured narratives in clinical notes to detect patients with CMD. We have shown that structured data are not sufficient to detect CMD and integrating unstructured data in the computational model boosts the performance significantly.

Trends in mortality rates by subtypes of heart disease in Mississippi, 1980-2013

BACKGROUND

Heart disease (HD) is the leading cause of death among Mississippians. However, trends in mortality rates for HD subtypes in Mississippi have not been adequately described. This study examined trends in mortality rates for HD subtypes among adults in Mississippi from 1980 through 2013.

METHODS

We used Mississippi Vital Statistics data to calculate age-specific mortality rates for HD subtypes for Mississippians age 35 and older. Cases were identified via underlying cause of death codes from the International Classification of Diseases, Ninth Revision (ICD-9) and Tenth Revision (ICD-10). We used Joinpoint software to calculate the average annual percent change (AAPC) in mortality rates for HD subtypes by race, sex, and age group.

RESULTS

Overall, the age-adjusted coronary heart disease (CHD) mortality rate among Mississippi adults decreased by 62.7% between 1980 and 2013, with an AAPC of -3.0% (95% CI -3.7 to -2.3), while the age-adjusted heart failure mortality rate increased by 66.7%, with an AAPC of 1.4% (95% CI 0.5 to 2.3). Trends varied across HD subtypes: Annual rates of hypertensive HD mortality increased significantly for men, for individuals age 35 to 54, and for individuals age 75 and older. CHD mortality experienced a significant annual decrease among all race, sex, and age subgroups, while heart failure increased significantly among women, whites, and individuals age 75 and older.

CONCLUSIONS

From 1980 to 2013, CHD mortality decreased significantly while heart failure mortality increased significantly among adult Mississippians. However, HD subtype trends differed by race, sex, and age group.

Sense of Coherence and Health-Related Quality of Life among Patients Undergoing Coronary Artery Bypass Grafting or Angioplasty

BACKGROUND

Every year, 4 million people die from cardiovascular disease (CAD) in Europe. As many as 800,000 of them die before they reach the age of 65. The ischemic heart disease is also the most common cause of death in Finland. The invasive treatments of the CAD, coronary artery bypass grafting (CABG) and percutaneous transluminal coronary angioplasty (PTCA) relieve symptoms and increase patient's health-related quality of life (HRQoL) in most of the cases. In this paper sense of coherence is discussed as related to health-related quality of life among CABG and PTCA patients in a one-year follow-up.

SAMPLE

The study sample consisted of consecutive male (N=439) and female (N=176) patients who were treated with the elective CABG or PTCA. The baseline data before the interventions were collected by structured interviews, the follow-up data by mailed self-administered questionnaires six and twelve months afterwards.

MEASURES

The sense of coherence was studied by using a 13-item SOC scale. HRQoL was measured by the 15D. It is a generic, multidimensional, standardized, self-administered instrument, which has both a profile and single index score property. The differences in both groups were defined by using T-tests. Follow-up outcomes were analysed by using analyses of variance for repeated measures.

RESULTS

Health-related quality of life increased in both groups during the follow-up. There was a correlation between health-related quality of life and sense of coherence in CABG and PTCA patients' group at baseline. The mean score of the 15D was lower in moderate sense of coherence tertile than in strong sense of coherence tertile in both groups. After six and twelve months the similar tendency existed in health-related quality of life and sense of coherence; patients who had poor or moderate sense of coherence had lower health-related quality of life than the patients with strong sense of coherence.

CONCLUSIONS

Sense of coherence was more stable among CABG patients than PTCA patients. In PTCA patients' group sense of coherence decreased during the follow-up time. In both patients' group the health-related quality of life increased statistically significant by 6 months. No significant change in health-related quality of life took place in either group from 6 to 12 months.

Performance criteria based on true and false classification and clinical outcomes. Influence of analytical performance on diagnostic outcome using a single clinical component

BACKGROUND

In the general classical model for diagnoses based on a single analytic component, distributions of healthy and diseased are compared and several investigations of varying analytical performance on the percentage of misclassifications have been published. A new concept based on an alternative type of diagnosing, based on sharp decision limits has been introduced in diagnostic guidelines, but only a few publications on investigation of analytical performance have been seen.

METHODS

The two diagnostic models (bimodal and unimodal) based on natural logarithmic Gaussian distributions are simulated.

RESULTS

In the bimodal model it is possible to evaluate the influence of prevalence of disease in combination with varying analytical performances. In the unimodal model the prevalence is pre-decided by the chosen decision limit. In this model the influence of analytical performance is investigated for diagnosing diabetes using haemoglobin A1c (HbA1c), and for patients with high and low risk for coronary heart disease defined by serum-cholesterol concentrations.

CONCLUSIONS

For HbA1c the guidelines and recommendations define a maximum inter-laboratory coefficient of variation of 3.5%, but this is in DCCT units (without a true zero-point), so after transformation to IFCC units (which are proportional) it was 5.2%, which allows for analytical bias as high as approximately ±9%. Consequently, analytical quality specifications should be separated as maximum bias and imprecision.

An analysis of chemical ingredients network of Chinese herbal formulae for the treatment of coronary heart disease

As a complex system, the complicated interactions between chemical ingredients, as well as the potential rules of interactive associations among chemical ingredients of traditional Chinese herbal formulae are not yet fully understood by modern science. On the other hand, network analysis is emerging as a powerful approach focusing on processing complex interactive data. By employing network approach in selected Chinese herbal formulae for the treatment of coronary heart disease (CHD), this article aims to construct and analyze chemical ingredients network of herbal formulae, and provide candidate herbs, chemical constituents, and ingredient groups for further investigation. As a result, chemical ingredients network composed of 1588 ingredients from 36 herbs used in 8 core formulae for the treatment of CHD was produced based on combination associations in herbal formulae. In this network, 9 communities with relative dense internal connections are significantly associated with 14 kinds of chemical structures with P<0.001. Moreover, chemical structural fingerprints of network communities were detected, while specific centralities of chemical ingredients indicating different levels of importance in the network were also measured. Finally, several distinct herbs, chemical ingredients, and ingredient groups with essential position in the network or high centrality value are recommended for further pharmacology study in the context of new drug development.

Genetic risk prediction and a 2-stage risk screening strategy for coronary heart disease

OBJECTIVE

Genome-wide association studies have identified several genetic variants associated with coronary heart disease (CHD). The aim of this study was to evaluate the genetic risk discrimination and reclassification and apply the results for a 2-stage population risk screening strategy for CHD.

APPROACH AND RESULTS

We genotyped 28 genetic variants in 24 124 participants in 4 Finnish population-based, prospective cohorts (recruitment years 1992-2002). We constructed a multilocus genetic risk score and evaluated its association with incident cardiovascular disease events. During the median follow-up time of 12 years (interquartile range 8.75-15.25 years), we observed 1093 CHD, 1552 cardiovascular disease, and 731 acute coronary syndrome events. Adding genetic information to conventional risk factors and family history improved risk discrimination of CHD (C-index 0.856 versus 0.851; P=0.0002) and other end points (cardiovascular disease: C-index 0.840 versus 0.837, P=0.0004; acute coronary syndrome: C-index 0.859 versus 0.855, P=0.001). In a standard population of 100 000 individuals, additional genetic screening of subjects at intermediate risk for CHD would reclassify 2144 subjects (12%) into high-risk category. Statin allocation for these subjects is estimated to prevent 135 CHD cases over 14 years. Similar results were obtained by external validation, where the effects were estimated from a training data set and applied for a test data set.

CONCLUSIONS

Genetic risk score improves risk prediction of CHD and helps to identify individuals at high risk for the first CHD event. Genetic screening for individuals at intermediate cardiovascular risk could help to prevent future cases through better targeting of statins.

Prognostic utility of BCIS myocardial jeopardy score for classification of coronary disease burden and completeness of revascularization

Several coronary disease scoring systems have been developed to predict procedural risk during revascularization. Many vary in complexity, do not specifically account for myocardium at risk, and are not applicable across all patient subsets. The British Cardiovascular Intervention Society myocardial jeopardy score (BCIS-JS) addresses these limitations and is applicable to all patients, including those with coronary artery bypass grafts or left main stem disease. We assessed the prognostic relevance of the BCIS-JS in patients undergoing percutaneous coronary intervention (PCI). A total of 663 patients who underwent PCI with previous left ventricular function assessment were retrospectively assessed for inclusion, incorporating 221 with previous coronary artery bypass grafting. Blinded observers calculated the BCIS-JS, before (BCIS-JS(PRE)) and after (BCIS-JS(POST)) PCI, using the revascularization index (RI) (RI = [BCIS-JS(PRE) - BCIS-JS(POST)]/BCIS-JS(PRE)), quantifying the extent of revascularization, 1 indicating full revascularization and 0 indicating no revascularization. The primary end point all-cause mortality, tracked via the Office of National Statistics. A total of 660 patients were included (66 ± 10.7 years), with 43 deaths (6.5%) occurring during 2.6 ± 1.1 years after PCI. All-cause mortality was directly related to BCIS-JS(PRE) (hazard ratio [HR] 2.96, 95% confidence interval [CI] 1.71 to 5.15, p = 0.001) and BCIS-JS(POST) (HR 4.02, 95% CI 2.41 to 6.68, p = 0.001). A RI of <0.67 was associated with increased mortality compared to a RI of ≥0.67 (HR 4.13, 95% CI 1.91 to 8.91, p = 0.0001). On multivariate analysis, a RI <0.67 (HR 1.99, 95% CI 1.03 to 3.87, p = 0.04), left ventricular dysfunction (HR 2.03, 95% CI 1.25 to 3.30, p = 0.004) and renal impairment (HR 3.75, 95% CI 1.48 to 8.64, p = 0.005) were independent predictors of mortality. In conclusion, the BCIS-JS predicts mortality after PCI and can assess the degree of revascularization, with more complete revascularization conferring a survival advantage in the medium term.

[Magnetic resonance tomography in diagnostics of coronary heart disease]

Contrast-enhanced magnetic resonance tomography (1.5 Tl) was used to examine 101 patients with coronary heart disease. It was shown that angina of effort was associated with disturbed myocardial perfusion manifest during the first passage of the contrast agent at sites with a hypointense signal. Patients with acute myocardial infarction exhibited, besides defective perfusion, hyperintense edematous regions on T2-weighted images as well as hyperintense sites of delayed contrast enhancement. The main symptoms of post-infarction cardiosclerosis in hyperintense zones of delayed contrast enhancement related to cicatrical lesions in myocardium. Disturbances of local contractility depending on the severity of ischemia and cicatrical lesions resulted in the impairment of overall left ventricular contractility.

Adult asthma and risk of coronary heart disease, cerebrovascular disease, and heart failure: a prospective study of 2 matched cohorts

Asthma has been associated with increased cardiovascular disease (CVD) risk. The authors ascertained the association of asthma with CVD and the roles that sex, concurrent allergy, and asthma medications may play in this association. They assembled a cohort of 203,595 Northern California adults with asthma and a parallel asthma-free referent cohort (matched 1:1 on age, sex, and race/ethnicity); both cohorts were followed for incident nonfatal or fatal CVD and all-cause mortality from January 1, 1996, through December 31, 2008. Each cohort was 66% female and 47% white. After adjustment for age, sex, race/ethnicity, cardiac risk factors, and comorbid allergy, asthma was associated with a 1.40-fold (95% confidence interval (CI): 1.35, 1.45) increased hazard of coronary heart disease, a 1.20-fold (95% CI: 1.15, 1.25) hazard of cerebrovascular disease, a 2.14-fold (95% CI: 2.06, 2.22) hazard of heart failure, and a 3.28-fold (95% CI: 3.15, 3.41) hazard of all-cause mortality. Stronger associations were noted among women. Comorbid allergy predicted CVD but did not synergistically increase the CVD risk associated with asthma. Only asthma patients using asthma medications (particularly those on oral corticosteroids alone or in combination) were at enhanced risk of CVD. In conclusion, asthma was prospectively associated with increased risk of major CVD. Modifying effects were noted for sex and asthma medication use but not for comorbid allergy.

Coding, recording and incidence of different forms of coronary heart disease in primary care

Objectives

To evaluate the coding, recording and incidence of coronary heart disease (CHD) in primary care electronic medical records.

Methods

Data were drawn from the UK General Practice Research Database. Analyses evaluated the occurrence of 271 READ medical diagnostic codes, including categories for ‘Angina’, ‘Myocardial Infarction’, ‘Coronary Artery Bypass Grafting’ (CABG), ‘percutaneous transluminal coronary angioplasty’ (PCTA) and ‘Other Coronary Heart Disease’. Time-to-event analyses were implemented to evaluate occurrences of different groups of codes after the index date.

Results

Among 300,020 participants aged greater than 30 years there were 75,197 unique occurrences of coronary heart disease codes in 24,244 participants, with 12,495 codes for incident events and 62,702 for prevalent events. Among incident event codes, 3,607 (28.87%) were for angina, 3,262 (26.11%) were for MI, 514 (4.11%) for PCTA, 161 (1.29%) for CABG and 4,951 (39.62%) were for ‘Other CHD’. Among prevalent codes, 20,254 (32.30%) were for angina, 3,644 (5.81%) for MI, 34,542 (55.09%) for ‘Other CHD’ and 4,262 (6.80%) for CABG or PCTA. Among 3,685 participants initially diagnosed exclusively with ‘Other CHD’ codes, 17.1% were recorded with angina within 5 years, 5.6% with myocardial infarction, 6.3% with CABG and 8.6% with PCTA. From 2000 to 2010, the overall incidence of CHD declined, as did the incidence of angina, but the incidence of MI did not change. The frequency of CABG declined, while PCTA increased.

Conclusion

In primary care electronic records, a substantial proportion of coronary heart disease events are recorded with codes that do not distinguish between different clinical presentations of CHD. The results draw attention to the need to improve coding practice in primary care. The results also draw attention to the importance of code selection in research studies and the need for sensitivity analyses using different sets of codes.

Multivariate modeling to identify patterns in clinical data: the example of chest pain

BACKGROUND

In chest pain, physicians are confronted with numerous interrelationships between symptoms and with evidence for or against classifying a patient into different diagnostic categories. The aim of our study was to find natural groups of patients on the basis of risk factors, history and clinical examination data which should then be validated with patients' final diagnoses.

METHODS

We conducted a cross-sectional diagnostic study in 74 primary care practices to establish the validity of symptoms and findings for the diagnosis of coronary heart disease. A total of 1199 patients above age 35 presenting with chest pain were included in the study. General practitioners took a standardized history and performed a physical examination. They also recorded their preliminary diagnoses, investigations and management related to the patient's chest pain. We used multiple correspondence analysis (MCA) to examine associations on variable level, and multidimensional scaling (MDS), k-means and fuzzy cluster analyses to search for subgroups on patient level. We further used heatmaps to graphically illustrate the results.

RESULTS

A multiple correspondence analysis supported our data collection strategy on variable level. Six factors emerged from this analysis: "chest wall syndrome", "vital threat", "stomach and bowel pain", "angina pectoris", "chest infection syndrome", and " self-limiting chest pain". MDS, k-means and fuzzy cluster analysis on patient level were not able to find distinct groups. The resulting cluster solutions were not interpretable and had insufficient statistical quality criteria.

CONCLUSIONS

Chest pain is a heterogeneous clinical category with no coherent associations between signs and symptoms on patient level.

Variant metabolic risk factor profile leading to premature coronary disease: time to define the syndrome of accelerated atherocoronary metabolic syndrome in Asian Indians

Coronary artery disease (CAD) is fast becoming a major morbidity and mortality burden in the developing world. The magnitude of the problem is predicted to exceed that of the developed world due to the sheer population numbers at risk. The Indian subcontinental ethnicity has been associated with a more severe form of CAD that has its onset at a younger age. This form of coronary disease and its risk factors seem quite different from what has been previously described in studies done among non-Asian Indian populations (mainly Caucasians living in the West). This fact has led to a situation where the current preventative and management protocols that have worked well in the non-Asian Indian populations, have failed to bring about the anticipated control over this disease condition, its progression and its incidence in this population. The time has come to identify the variant of CAD in the Asian Indian ethnic population and the associated metabolic factors, as a separate and distinct entity, and as a unique syndrome. This distinction may facilitate more focused and ethnicity-specific studies to be carried out to unravel the mysteries surrounding the clinical, pathological and molecular biological aspects of the CAD syndrome among Asian Indian ethnics. The outcomes and findings of such investigations may help gain a stranglehold on this rapidly-progressing disease condition among the populations in emerging and densely-populated economies of the South Asian region, as well as among millions of Asian-Indian ethnics living all over the world. Thus we may brace ourselves to better address or even prevent what has been dubbed "the next major clinical epidemic of our times".

Eligibility of individuals with subclinical coronary artery calcium and intermediate coronary heart disease risk for reclassification (from the Framingham Heart Study)

Coronary artery calcium (CAC) predicts risk for coronary heart disease (CHD) events and perhaps CAC testing may further stratify risk in individuals at intermediate CHD risk. We sought to determine the percentage of participants at intermediate CHD risk who could potentially be reclassified as having a high CHD risk based on the presence of a high CAC score and the prevalence, treatment, and control of CHD risk factors in this group. Framingham Heart Study Offspring and Third Generation cohort participants underwent multidetector computed tomography (n = 3,529, mean age 51 years, 48% women). High CAC was defined as >or=90th age- and gender-specific percentiles based on a healthy reference group or by an absolute modified Agatston score of 100 HU. Prevalence of CHD risk factors (hypertension, hypercholesterolemia, high low-density lipoprotein cholesterol, low high-density lipoprotein cholesterol, smoking, and obesity), their treatment, and control was compared between nondiabetic participants with and without high CAC. Of the 595 participants at intermediate CHD risk, 22% had CAC >or=90th percentile and 39% had CAC >or=100 and could be eligible for reclassification as having a high CHD risk based on the presence of a high CAC score. There were no statistically significant differences in prevalence, treatment, and control of risk factors between those with and without high CAC. In conclusion, prevalence of CHD risk factors did not differ between intermediate-risk participants with and without high CAC. Approximately 25% of intermediate-risk individuals have high CAC scores and may be eligible for reclassification into a higher-risk category.

Impact of adding a single allele in the 9p21 locus to traditional risk factors on reclassification of coronary heart disease risk and implications for lipid-modifying therapy in the Atherosclerosis Risk in Communities study

BACKGROUND

A single-nucleotide polymorphism on chromosome 9p21, rs10757274 (9p21 allele), has been shown to predict coronary heart disease (CHD) in whites. We evaluated whether adding the 9p21 allele to traditional risk factors (RFs) improved CHD risk prediction in whites from the Atherosclerosis Risk in Communities study and whether changes in risk prediction would modify lipid therapy recommendations.

METHODS AND RESULTS

Whites (n=9998) in the Atherosclerosis Risk in Communities study for whom the 9p21 genotype and traditional RF information was available were included. Using Cox proportional hazards models, the Atherosclerosis Risk in Communities Cardiovascular Risk Score, which is based on traditional RFs, was determined. A total of 1349 individuals (13.5%) developed incident CHD events during a period of 14.6 years. Adding the 9p21 allele to traditional RFs was associated with a hazard ratio of incident CHD of 1.2 per allele (P<0.000003) and a significant increase in the area under the curve of the receiver operating characteristic from 0.782 to 0.786 (95% CI, 0.001, 0.007). The 9p21 allele's greatest influence to the Atherosclerosis Risk in Communities Cardiovascular Risk Score was observed in the intermediate-low (>5% to 10% to 100 mg/dL.

CONCLUSIONS

Adding the 9p21 allele to traditional RFs in whites in the Atherosclerosis Risk in Communities study modestly improved CHD risk prediction in the intermediate categories.

Percutaneous coronary interventions for non-acute coronary artery disease: a quantitative 20-year synopsis and a network meta-analysis

BACKGROUND

Over the past 20 years, percutaneous transluminal balloon coronary angioplasty (PTCA), bare-metal stents (BMS), and drug-eluting stents (DES) succeeded each other as catheter-based treatments for coronary artery disease. We undertook a systematic overview of randomised trials comparing these interventions with each other and with medical therapy in patients with non-acute coronary artery disease.

METHODS

We searched Medline for trials contrasting at least two of the four interventions (PTCA, BMS, DES, and medical therapy). Eligible outcomes were death, myocardial infarction, coronary artery bypass grafting, target lesion or vessel revascularisation, and any revascularisation. Random effects meta-analyses summarised head-to-head (direct) comparisons, and network meta-analyses integrated direct and indirect evidence.

FINDINGS

61 eligible trials (25 388 patients) investigated four of six possible comparisons between the four interventions; no trials directly compared DES with medical therapy or PTCA. In all direct or indirect comparisons, succeeding advancements in percutaneous coronary intervention did not produce detectable improvements in deaths or myocardial infarction. The risk ratio (RR) for indirect comparisons between DES and medical therapy was 0.96 (95% CI 0.60-1.52) for death and 1.15 (0.73-1.82) for myocardial infarction. By contrast, we recorded sequential significant reductions in target lesion or vessel revascularisation with BMS compared with PTCA (RR 0.68 [0-60.0.77]) and with DES compared with BMS (0.44 [0.35-0.56]). The RR for the indirect comparison between DES and PTCA for target lesion or vessel revascularisation was 0.30 (0.17-0.51).

INTERPRETATION

Sequential innovations in the catheter-based treatment of non-acute coronary artery disease showed no evidence of an effect on death or myocardial infarction when compared with medical therapy. These results lend support to present recommendations to optimise medical therapy as an initial management strategy in patients with this disease.

Changes in heart rate variability caused by coronary angioplasty depend on the localisation of coronary lesions

BACKGROUND

Coronary angioplasty (PTCA) is a common treatment method in patients with coronary heart disease, but its effects on heart rate variability (HRV) have not been well established.

AIM

To verify whether the localisation of coronary lesion undergoing PTCA affects HRV parameters.

METHODS

Ninety six consecutive individuals underwent elective coronary angiography with subsequent ad hoc successful PTCA. Two five-minute ECG were recorded, one before PTCA and the second 24-hour after PTCA. The HRV indices were determined by means of classical and 'new' mathematical models.

RESULTS

The PTCA-induced changes in HRV variables depended on the localisation of dilated lesion. PTCA of the circumflex artery revealed the most significant HRV changes--a decrease in value of domain indices: Yeh DI (0.033+/-0.031 vs. 0.011+/-0.006 un/unitless, p=0.005), Yeh II (0.053+/-0.039 vs. 0.032+/-0.013 un, p=0.017), Organ BAND (9.101+/-9.245 vs. 4.62+/-2.205 bpm/beat per minute, p=0.031), Huey STV (208.821+/-262.248 vs. 76.444+/-35.281 bpm, p=0.013), Dalton MABB (15.733+/-16.575 vs. 7.57+/-4.89 ms, p=0.015), Dalton SD (48.741+/-37.468 vs. 27.759+/-10.533 ms, p=0.015), Zugaib STV (0.0129+/-0.0132 vs. 0.005+/-0.003 un, p=0.005), SDNN (27.204+/-18.592 vs. 21.329+/-32.784 ms, p=0.044), rMSSD (56.239+/-19.751 vs. 51.496+/-43.889 ms, p=0.025) and increased LF/HF (2.384+/-2.072 vs. 5.632+/-5.379 un, p=0.044). Angioplasty of the right coronary artery resulted in decreased AR TP (18.273+/-2.296 vs. 17.085+/-2.256 ms(2), p=0.017) and alteration of the sympathovagal balance of the autonomic nervous system towards predominance of sympathetic activity: AR LF (0.264+/-0.029 vs. 0.284+/-0.040 un, p=0.007), LF/HF (4.310+/-4.457 vs. 6.958+/-7.013 un, p=0.018), HF (0.199+/-0.165 vs. 0.141+/-0.157 un, p=0.031), AR HF (0.647+/-0.043 vs. 0.621+/-0.054 un, p=0.014). PTCA of the left anterior descending artery caused no change.

CONCLUSION

Changes in heart rate variability caused by coronary angioplasty depend on the localisation of coronary lesions.

C-reactive protein and reclassification of cardiovascular risk in the Framingham Heart Study

BACKGROUND

The relationship of circulating levels of high-sensitivity C-reactive protein (CRP) with cardiovascular disease (CVD) risk, particularly with consideration of effects at intermediate levels of risk, has not been fully assessed.

METHODS AND RESULTS

Among 3006 offspring participants in the Framingham Heart Study free of CVD (mean age, 46 years at baseline), there were 129 hard coronary heart disease (CHD) events and 286 total CVD events during 12 years of follow-up. Cox regression, discrimination with area under the receiver operating characteristic curve, and net reclassification improvement were used to assess the role of CRP on vascular risk. In an age-adjusted model that included both sexes, the hazard ratios for new hard CHD and total CVD were significantly associated with higher CRP levels. Similar analyses according to increasing homocysteine level showed significant protective associations for hard CHD but not for total CVD. In multivariable analyses that included age, sex, systolic blood pressure, total cholesterol, high-density lipoprotein cholesterol, diabetes mellitus, current smoking, hypertension treatment, and homocysteine, the log CRP level remained significantly related to development of hard CHD and total CVD and provided moderate improvement in the discrimination of events. The net reclassification improvement when CRP was added to traditional factors was 5.6% for total CVD (P=0.014) and 11.8% for hard CHD (P=0.009).

CONCLUSIONS

Circulating levels of CRP help to estimate risk for initial cardiovascular events and may be used most effectively in persons at intermediate risk for vascular events, offering moderate improvement in reclassification of risk.

Brachial artery pulsatility index change 1 minute after 5-minute forearm compression: comparison with flow-mediated dilatation

OBJECTIVE

Endothelial impairment evaluation by sonographic measurement of flow-mediated dilatation (FMD) has become broadly used. However, this method has 2 main caveats: the dilatation depends on the baseline arterial diameter, and a high precision level is required. Vasodilatation leads to an amplified fall in impedance. We hypothesized that assessment of the pulsatility index change (PI-C) 1 minute after 5-minute forearm compression might evaluate that fall in impedance. The aim of this study was to compare the PI-C with FMD.

METHODS

Flow-mediated dilatation and the PI-C were assessed in 51 healthy women aged between 35.1 and 67.1 years. We correlated both FMD and the PI-C with age, body mass index, waist circumference, cholesterol level, high-density lipoprotein level, glucose level, systolic and diastolic blood pressure, pulse pressure, brachial artery diameter, simplified Framingham score, intima-media thickness, and carotid stiffness index. Intraclass correlation coefficients between 2 FMD and PI-C measurements were also examined.

RESULTS

Only FMD correlated with baseline brachial diameter (r = -0.53). The PI-C had a high correlation with age, body mass index, waist circumference, cholesterol level, systolic blood pressure, pulse pressure, simplified Framingham score, and intima-media thickness. The correlation between FMD and the PI-C was high (r = -0.66). The PI-C had a higher intraclass correlation coefficient (0.991) than FMD (0.836) but not brachial artery diameter (0.989).

CONCLUSIONS

The PI-C had a large correlation with various markers of cardiovascular risk. Additionally, PI-C measurement does not require offline analysis, extra software, or electrocardiography. We think that the PI-C could be considered a marker of endothelial function. However, more studies are required before further conclusions.

The relationship between carotid and coronary atherosclerotic damage in dialysis patients

BACKGROUND

Data relating carotid ultrasound (CU) to atherosclerotic damage evaluated by coronary angiography in hemodialysis patients are scarce.

METHODS

We carried out a cross-sectional study in 33 uremic subjects (age 55 +/- 12 years, 22 male, 7 diabetic), who have been on dialysis for 41 +/- 48 months (range 2-192). Twenty-two underwent a coronary angiography in order to complete clinical evaluation for inclusion on the kidney transplantation waiting list, and 11 because of coronary artery disease (CAD); Gensini's score was calculated. Intima-media thickness (IMT) and presence of plaques were related to the degree of coronary stenosis and to cardiovascular risk factors. Patients were divided into two groups depending on mean IMT (group 1 IM <or= 0.9 mm, n=18; group 2 IMT>0.9 mm, n=15).

RESULTS

Group 2 was older (60 +/- 8 vs 50 +/- 12 year, p=0.01), had higher frequency of CAD (53 vs 16%, p=0.02) and had higher prevalence of coronary artery stenosis >or= 75% in the right (60 vs 22%, p=0.02), left anterior descending (46 vs 16%, p=0.06) and left circumflex coronary arteriers (60 vs 11%, p=0.05) than group 1. IMT was not related to the degree of CAD evaluated by Gensini's score. IMT sensibility and specificity in detecting the presence of hemodynamically significant coronary stenosis were 64% and 68%, respectively. Coronary narrowing was correlated with the degree of stenosis of common, internal and external carotid arteries (Spearman's rank correlation coefficient). During two years of follow-up, six major cardiac events were recorded and they were related to Gensini's score.

CONCLUSIONS

In uremic patients, ultrasonographic evaluation of carotid arteries is a simple, noninvasive examination that could be a helpful tool in detecting coronary atherosclerotic damage, but IMT does not appear to add more information regarding risk stratification of CAD.

Validity of the Framingham point scores in the elderly: results from the Rotterdam study

BACKGROUND

The National Cholesterol Education Program recommends assessing 10-year risk of coronary heart disease (CHD) in individuals free of established CHD with the Framingham Point Scores (FPS). Individuals with a risk >20% are classified as high risk and are candidates for preventive intervention. We aimed to validate the FPS in a European population of elderly subjects.

METHODS

Subjects free of established CHD at baseline were selected from the Rotterdam study, a population-based cohort of subjects 55 years or older in The Netherlands. We studied calibration, discrimination (c-index), and the accuracy of high-risk classifications. Events consisted of fatal CHD and nonfatal myocardial infarction.

RESULTS

Among 6795 subjects, 463 died because of CHD and 336 had nonfatal myocardial infarction. Predicted 10-year risk of CHD was on average well calibrated for women (9.9% observed vs 10.1% predicted) but showed substantial overestimation in men (14.3% observed vs 19.8% predicted), particularly with increasing age. This resulted in substantial number of false-positive classifications (specificity 70%) in men. In women, discrimination of the FPS was better than that in men (c-index 0.73 vs 0.63, respectively). However, because of the low baseline risk of CHD and limited discriminatory power, only 33% of all CHD events occurred in women classified as high risk.

CONCLUSIONS

The FPS need recalibration for elderly men with better incorporation of the effect of age. In elderly women, FPS perform reasonably well. However, maintaining the rational of the high-risk threshold requires better performing models for a population with low incidence of CHD.

Noninvasive assessment of plaque characteristics with multislice computed tomography coronary angiography in symptomatic diabetic patients

OBJECTIVE

Cardiovascular events are high in patients with type 2 diabetes, whereas their risk stratification is more difficult. The higher risk may be related to differences in coronary plaque burden and composition. The purpose of this study was to evaluate whether differences in the extent and composition of coronary plaques in patients with and without diabetes can be observed using multislice computed tomography (MSCT).

RESEARCH DESIGN AND METHODS

MSCT was performed in 215 patients (86 [40%] with type 2 diabetes). The number of diseased coronary segments was determined per patient; each diseased segment was classified as showing obstructive (> or = 50% luminal narrowing) disease or not. In addition, plaque type (noncalcified, mixed, and calcified) was determined. Plaque characteristics were compared in patients with and without diabetes. Regression analysis was performed to assess the correlation between plaque characteristics and diabetes.

RESULTS

Patients with diabetes showed significantly more diseased coronary segments than nondiabetic patients (4.9 +/- 3.5 vs. 3.9 +/- 3.2, P = 0.03) with more nonobstructive (3.7 +/- 3.0 vs. 2.7 +/- 2.4, P = 0.008) plaques. Relatively more noncalcified (28 vs. 19%) and calcified (49 vs. 43%) and less mixed (23 vs. 38%) plaques were observed in patients with diabetes (P < 0.0001). Diabetes correlated with the number of diseased segments and nonobstructive, noncalcified, and calcified plaques.

CONCLUSIONS

Differences in coronary plaque characteristics on MSCT were observed between patients with and without diabetes. Diabetes was associated with higher coronary plaque burden. More noncalcified and calcified plaques and less mixed plaques were observed in diabetic patients. Thus, MSCT may be used to identify differences in coronary plaque burden, which may be useful for risk stratification.

[CT coronary angiography: examination technique, clinical results, and outlook on future developments]

Multislice computed tomography (MSCT) after intravenous contrast agent administration enables visualization of the coronary arteries with high spatial resolution (voxel sizes down to 0.5 x 0.35 x 0.35 mm (3)) and a short scan time. Magnetic resonance imaging (MRI) is also intensively studied with respect to the noninvasive detection of coronary artery stenosis and thus the detection of coronary artery disease (CAD) without radiation exposure but is not equal to MSCT at present. This article provides an overview of the historical development of CT coronary angiography from 4-slice CT to 16-slice CT and 64-slice CT. A crucial aspect of this development is the improvement in image quality resulting from shorter breath-hold periods and the reduced gantry rotation time. Other techniques that appear to considerably improve image quality and accuracy and make CT independent of patient heart rates are multi-segment reconstruction and dual-source CT. Sublingual nitroglycerin as well as oral or intravenous betablocker administration should be considered in relation to the diagnostic question to be answered and the patient's heart rate. In the studies available CT coronary angiography with at least 12 simultaneous detector rows has a sensitivity of 96.9 % and a specificity of 75.3 % at the patient level. Especially the negative predictive value of CT (94.6 %) emphasizes the idea that this technique may reliably exclude CAD in patients with intermediate pretest likelihood. In the near future, 256-slice CT will allow examination of the entire heart during one heartbeat or even 4D CT scanning with simultaneous assessment of myocardial perfusion. Automatic or semiautomatic software tools will assume a central place in detecting and quantifying coronary artery stenoses and plaques as well as in the analysis of cardiac function in the clinical setting over the next years. Prior to its routine clinical use, the cost-effectiveness of CT coronary angiography must be determined and the clinical role of MSCT must be investigated in multi-center studies including different patient populations.

Cyphering the complexity of coronary artery disease using the syntax score to predict clinical outcome in patients with three-vessel lumen obstruction undergoing percutaneous coronary intervention

The Syntax score (SXscore) was recently developed as a comprehensive angiographic scoring system aiming to assist in patient selection and risk stratification of patients with extensive coronary artery disease undergoing contemporary revascularization. A validation of this angiographic classification scheme is lacking. We assessed its predictive value in patients who underwent percutaneous intervention (PCI) for 3-vessel disease and explored its performance in comparison with the modified lesion classification system of the American Heart Association/American College of Cardiology. The SXscore, applied to 1,292 lesions in 306 patients who underwent PCI for 3-vessel disease in the Arterial Revascularization Therapies Study Part II, was 4 to 54.5, and after a median of 370 days (range 274 to 400) predicted the rate of major adverse cardiac and cerebrovascular events (hazard ratio 1.08/U increase, 95% confidence interval 1.05 to 1.11, p <0.0001), with patients in the highest SXscore tertile having a significantly higher event rate (27.9%) than patients in the lowest tertile (8.7%, hazard ratio 3.5, 95% confidence interval 1.7 to 7.4, p = 0.001). By multivariable analyses, SXscore independently predicted outcome with an almost fourfold adjusted increase in the risk of major adverse cardiac and cerebrovascular events in patients with high versus low values based on the discrimination level provided by classification and regression tree analysis. Compared with the modified lesion classification scheme of the American Heart Association/American College of Cardiology, SXscore showed a greater discrimination ability (c-index 0.58 +/- 0.08 vs 0.67 +/- 0.08, respectively, p <0.001) and a better goodness of fit with the Hosmer-Lemeshow statistic. In conclusion, the SXscore is a promising tool to risk stratify outcome in patients with extensive coronary artery disease undergoing contemporary PCI.

Challenges in the phenotypic characterisation of patients in genetic studies of coronary artery disease

Coronary artery disease and acute myocardial infarction are complex traits in which there has been recent research to identify the principal genes that engender susceptibility or provide protection. Although there has been exceptional progress in the technology, which now allows genotyping of hundreds of thousands of single-nucleotide polymorphisms in each individual, there remains a pattern of inconsistency in the studies performed to date, in part owing to the difficulties in defining cases and controls. In this paper, salient issues to facilitate research in this important field are reviewed.

Anxiety enhances the detrimental effect of depressive symptoms on health status following percutaneous coronary intervention

OBJECTIVE

We examined whether anxiety has incremental value to depressive symptoms in predicting health status in patients undergoing percutaneous coronary intervention (PCI) treated in the drug-eluting stent era.

METHODS

A series of consecutive patients (n=692) undergoing PCI as part of the Rapamycin-Eluting Stent Evaluated at Rotterdam Cardiology Hospital registry completed the Hospital Anxiety and Depression Scale at 6 months and the Short-Form Health Survey (SF-36) at 6 and 12 months post-PCI.

RESULTS

Of 692 patients, 471 (68.1%) had no symptoms of anxiety nor depression, 62 (9.0%) had anxiety only, 59 (8.5%) had depressive symptoms only, and 100 (14.5%) had co-occurring symptoms. There was an overall significant improvement in health status between 6 and 12 months post-PCI (P<.001); the interaction effect for time by psychological symptoms was also significant (P=.003). Generally, patients with co-occurring symptoms reported significantly poorer health status compared with the other three groups (Ps <.001). Patients with co-occurring symptomatology were also at greater risk of impaired health status on six of the eight subdomains of the SF-36 compared with the other three symptom groups, adjusting for baseline characteristics and health status at 6 months.

CONCLUSION

Patients with co-occurring symptoms of anxiety and depression reported poorer health status compared with anxious or depressed-only patients and no-symptom patients, showing that anxiety has incremental value to depressive symptoms in identifying PCI patients at risk for impaired health status treated in the drug-eluting stent era.

Results of coronary artery endarterectomy and coronary artery bypass grafting for diffuse coronary artery disease

BACKGROUND

Coronary artery endarterectomy with coronary artery bypass grafting for diffuse coronary artery disease has been associated with increased morbidity and mortality. We evaluated our institutional experience to redefine the role of coronary endarterectomy for diffuse coronary artery disease.

METHODS

From 1985 to 2002 isolated coronary artery endarterectomy with coronary artery bypass grafting was performed in 1,478 consecutive patients. The short-term outcomes were compared with concurrent series of conventional coronary artery bypass graft surgery, and risk factors for adverse outcomes after coronary endarterectomy were identified.

RESULTS

Patients in the coronary endarterectomy group were of higher risk with increased incidence of comorbidities and three-vessel coronary disease. The operative mortality (3.2% versus control 2.2%; p = 0.03) and the incidence of major postoperative morbidity (not significant) were comparable between the groups. Prolonged cardiopulmonary bypass time, recent acute myocardial infarction, redo surgery, and poor ventricular function were important predictors of in-hospital mortality. Vessel endarterectomized, technique of endarterectomy, and cardiopulmonary bypass versus off-pump technique did not alter results. At long-term follow-up, 5-year and 10-year survivals were 83% +/- 5%, and 74% +/- 3%, respectively, and freedom from angina at 5 and 10 years was 75% +/- 5%, and 69% +/- 4%, respectively, with 96% of survivors in New York Heart Association class II.

CONCLUSIONS

In selected patients with diffuse coronary artery disease, coronary endarterectomy can be used as a tool for myocardial revascularization. The operative mortality and major morbidity were comparable or similar to coronary artery bypass grafting, and short-term and long-term results were favorable.

B-type natriuretic peptide as an integrated risk marker in non-ST elevation acute coronary syndromes

BACKGROUND

Elevated B-type natriuretic peptide (BNP) levels show prognostic significance in patients with non-ST elevation acute coronary syndromes, but the underlying pathophysiology remains unclear.

METHODS

Two hundred and eighteen consecutive patients with non-ST elevation acute coronary syndromes were studied retrospectively. We compared clinical characteristics between groups with plasma BNP levels above or below the median value, and performed multiple logistic regression analysis to identify independent predictors of supramedian BNP levels.

RESULTS

Patients with supramedian BNP (>or=134 pg/ml) were more likely to be elderly (>or=75 years) with diabetes, prior myocardial infarction, and a history of coronary artery bypass grafting. They also had higher cardiac marker levels, a higher Killip class, a lower left ventricular ejection fraction, renal insufficiency (creatinine>or=1.5 mg/dl), and more 3-vessel disease. In multivariate analysis, the strongest independent predictor of supramedian BNP levels was 3-vessel disease (chi(2)=12.1), followed by old age (chi(2)=10.3), renal insufficiency (chi(2)=5.0), higher Killip class (chi(2)=4.2), and lower left ventricular ejection fraction (chi(2)=4.1). All 11 patients dying in hospital had supramedian BNP levels. Its elevation reflected the risk of 3-vessel disease and coronary artery bypass grafting regardless of troponin status.

CONCLUSION

In unselected patients with non-ST elevation acute coronary syndromes, an increase of BNP is correlated with the extent of myocardial ischemia, age, renal insufficiency, and ventricular dysfunction. It may be a useful biomarker integrating conventional risk factors for risk stratification in this population.

Coronary Angiography, Lesion Classification and Severity Assessment

A joint task force of the American College of Cardiology and the American Heart Association established criteria in 1988 to estimate procedural success and complication rates after balloon angioplasty, based on the presence or absence of specific lesion characteristics. Advances in the technique of coronary intervention over the years have changed the management of patients who have coronary artery disease, resulting in safer and more effective percutaneous revascularization in patients previously deemed at high risk for nonsurgical approaches. Coronary angiography (visual or quantitative) is a simple,easy, and mostly reliable tool in the assessment of lesion severity, but it may be inconclusive in the borderline lesions (40% to 60% diameter obstruction). Anatomical (using intravascular ultrasound) and physiological (using coronary flow reserve or fractional flow reserve) lesion assessment may be required for adequate lesion evaluation, before and after percutaneous coronary intervention.

[Pathophysiology of acute coronary syndrome]

This article reviews the current understanding of the pathophysiology of acute coronary syndrome and how these concepts have altered our clinical approach to the acute phase of coronary heart disease. Thrombosis due to erosion or, in most cases, rupture of a vulnerable atherosclerotic plaque underlies most acute coronary syndromes. The protective fibrous cap undergoes degradative processes controlled by inflammatory mediators that break down the interstitial collagen within the fibrous cap. Thrombus formation depends on factors in the solid-phase of the ruptured plaque as well as on fluid-phase determinants in blood. Depending on the degree of thrombus formation the subsequent obstruction of the coronary artery is followed clinically by unstable angina, non-ST- and ST-segment elevation myocardial infarction.

A new proposed simplified classification of coronary artery bifurcation lesions and bifurcation interventional techniques

Current classification systems of coronary bifurcation lesions are confusing and difficult to memorize. As coronary revascularization techniques become increasingly complex, it is important to establish a universal classification system. This manuscript proposes a simplified classification system that uses a combination of letters and numbers to provide a clinically relevant anatomic description of a given coronary artery bifurcation lesion. This classification consists of the prefix B (for Bifurcation lesion), followed by the addition of 4 separate suffixes. The first suffix consists of one of the letters C, N, S, or L. C = Close to the bifurcation: the lesion is close to a bifurcation, but the distance from the carina is more than the width of the plaque protruding into the lumen; N = Bifurcation lesion with one branch being Nonsignificant: nonsignificant being defined as less than 2.0 mm vessel diameter; S = Small proximal segment; or L = Large proximal segment: large defined as more than two-thirds of the sum of the diameters of both branch vessels. The second suffix describes the number of diseased ostia. 1M = only the Main vessel ostium is involved; 1S = only the Side branch ostium is involved; or 2 = both ostia are involved. The third suffix classifies the angle between the bifurcation vessels and uses the letters V or T; V = the angle between the two branches is less than 70 degrees, T = angle more than 70 degrees. The fourth suffixes are optional: CA for calcified, LM for left main involvement.

Association Between Surgeon and Hospital Volume in Coronary Artery Bypass Graft Surgery Outcomes: A Population-Based Study

BACKGROUND

We have found no study conducted outside of the United States on the association between physician volume and patient outcomes after coronary artery bypass graft surgery. The aim of this study is to examine the association between surgeon-hospital coronary artery bypass graft volume and patient outcomes using three-year population-based data on Taiwan.

METHODS

This study uses the Taiwan National Health Insurance Research Database covering the period 2000 to 2002, with the study sample comprising 9,895 first-time coronary artery bypass graft admissions, treated by 316 surgeons in 46 hospitals.

RESULTS

Of the sampled patients, 356 (3.6%) were discharged after death. Those patients treated by low-volume (1-50 cases) surgeons had significantly higher mortality rates than those treated by medium-volume (51-100 cases) surgeons (7.0% vs 3.8%), high-volume (101-150 cases) surgeons (7.0% vs 2.7%), or very-high-volume (> or = 151 cases) surgeons (7.0% vs 3.2%). However, hospital coronary artery bypass graft volume alone is an insufficient predictor of hospital in-patient deaths (p = 0.078). The adjusted odds ratio of hospital in-patient deaths declined with increasing surgeon volume, with the odds of in-patient death for those patients treated by low-volume surgeons being 1.52 times those of medium-volume surgeons, 1.89 times those of high-volume surgeons, and 2.04 times those of very-high-volume surgeons.

CONCLUSIONS

We conclude that for all coronary artery bypass graft surgeries taking place in Taiwan, the skill and experience of individual surgeons is a more critical factor for patient outcome than either hospital equipment or surgical teams.

Multidetector computed tomography for the diagnosis of coronary artery disease: a systematic review

PURPOSE

The study's purpose was to determine the sensitivity and specificity of contrast-enhanced multidetector computed tomography (CT) for the detection of coronary artery disease.

SUBJECTS AND METHODS

A search of the literature in all languages was performed incorporating both electronic and manual components. Manual reference checks of recent reviews and all original investigations supplemented the electronic searches.

RESULTS

Average sensitivity for patient-based detection of significant (>50% or > or =50%) stenosis was 61 of 64 (95%) with 4-slice CT, 276 of 292 (95%) with 16-slice CT, and 47 of 47 (100%) with 64-slice CT. Average specificity was 84% for 4-slice CT, 84% for 16-slice CT, and 100% for 64-slice CT. The sensitivity for a significant stenosis in evaluable segments was 307 of 372 (83%) with 4-slice CT, 1023 of 1160 (88%) with 16-slice CT, and 165 of 176 (94%) with 64-slice CT. Average specificity was 93% or greater with all multidetector CT. Seventy-eight percent of segments were evaluable with 4-slice CT, 91% with 16-slice CT, and 100% with 64-slice CT. Stenoses in proximal and mid-segments were shown with a higher sensitivity than distal segments. Left main stenosis was identified with high sensitivity with all multidetector CT, but sensitivity in other vessels increased with an increasing number of detectors.

CONCLUSION

Multidetector CT has the potential to be used as a screening test in appropriate patients. Contrast-enhanced 16-slice CT seems to be reasonably sensitive and specific for the detection of significant coronary artery disease but has shortcomings. Preliminary data with 64-slice CT suggest that it is more sensitive and specific.

Acute coronary syndromes

Despite technologic advances in many diagnostic fields, the 12-lead ECG remains the basis for early identification and management of an acute coronary syndrome. This article reviews the use of the ECG in acute coronary syndromes.

Image Fusion of Coronary Tree and Regional Cardiac Function Image Using Multislice Computed Tomography

BACKGROUND

Although trials of image fusion, such as positron emission computed tomography and multislice spiral computed tomography (MSCT), have already demonstrated clinical usefulness, fusion of the coronary artery image and functional image by MSCT alone has not been reported yet. Here, a new idea of data analysis is proposed in which both regional cardiac function and the responsible coronary arteries can be assessed by a fused image.

METHODS AND RESULTS

The study group comprised 5 patients with coronary artery disease. At the first procedure, 3 dimensional (D) volume rendering coronary artery (3D-CTA) was extracted. At the second procedure, the systolic regional wall thickening was calculated and the color 3D functional surface map of systolic wall thickening (3D-SWT) was generated. At the final procedure, 3D-SWT was superimposed on the left ventricular surface with 3D-CTA using a transparency. In all 5 patients, image fusion of the coronary tree and cardiac function was correctly generated. Image fusion can be displayed as clear 3D images, offering better orientation to help assess both the coronary artery and regional function.

CONCLUSIONS

Image fusion of coronary computed tomography angiography and the functional map by MSCT is potentially a new method of assessing both the coronary artery and cardiac function.

Correlation of exercise capacity with high-sensitive C-reactive protein in patients with stable coronary artery disease

BACKGROUND

There is growing evidence for the association between physical activity and systemic inflammatory markers in healthy individuals and populations with a low prevalence of coronary artery disease (CAD). However, the association between fitness and CRP in patients with stable CAD treated with medications known to influence the inflammatory response, such as statins and aspirin, is not well known.

METHODS

We prospectively enrolled 209 patients with angiographically documented CAD (161 men; age 63 +/- 10 years; 1-/2-/3-vessel disease in 42%, 34%, and 24% of patients, respectively; left ventricular ejection fraction 60% +/- 13%). Fitness level was assessed by maximal exercise testing. CRP was measured in all patients using high-sensitivity immunoassay.

RESULTS

Fitness level was inversely correlated with natural log-transformed CRP level (r = -0.28, P < .001). After multivariate linear regression adjustment for age, sex, body mass index, waist circumference, smoking status, educational level, diabetes, hypertension, modality of exercise testing, exercise-induced ischemia, extent of CAD, medication use, leukocyte count, hemoglobin, renal function, glucose level, and cholesterol level, exercise capacity remained inversely correlated with CRP level (beta = -.226, P = .001). Other covariates associated with CRP remaining in the final model were leukocyte count (beta = .348), pack-years of smoking (beta = .185), diabetes status (beta = -.201), hemoglobin concentration (beta = -.187), and high-density lipoprotein cholesterol level (beta = -.149).

CONCLUSIONS

These results indicate that exercise capacity is inversely correlated with CRP level in patients with known stable CAD irrespective of extent of CAD and standard medication for secondary prevention.

Is Reoperation Still a Risk Factor in Coronary Artery Bypass Surgery?

BACKGROUND

Hospital mortality for reoperative coronary artery bypass grafting (CABG) is approaching that of primary CABG. This raises two questions: (1) has experience neutralized the risk of reoperation attributable to its greater difficulty, or (2) has experience neutralized the risk attributable to the higher-risk profile of reoperative patients?.

METHODS

From 1990 to 2003, 21,568 CABG procedures were performed, of which 4,518 (21%) were reoperations: 3,919 first, 552 second, 43 third, 3 fourth, and 1 fifth. Reoperative patients had a higher-risk profile than primary patients, with more vascular disease, left ventricular dysfunction, and coronary artery disease (all p < 0.0001). Logistic regression was used to identify factors associated with hospital death and to develop a propensity score for reoperation, which was used to (1) adjust multivariable analyses of death and (2) compare outcomes in matched patients.

RESULTS

Hospital mortality was 4.3% (168 of 3,919) for first reoperation, 5.1% (28 of 552) for second, and 6.4% (3 of 47) for third or more, compared with 1.5% (263 of 17,050) for primary operations. Risk of both primary and reoperative CABG decreased with experience (p > 0.0002); however, reoperative risk fell markedly in the mid-1990s. In both the overall and matched-pairs analyses, reoperation was a risk factor before 1997 (p < or = 0.008), but not after (p = 0.2). Reoperation within 1 year of previous CABG increased risk (p < 0.0001). Risk attributable to left ventricular dysfunction decreased with experience (p = 0.05).

CONCLUSIONS

Hospital mortality for reoperative CABG has been consistently higher than for primary operation, but this difference has narrowed considerably. Patient characteristics, not reoperation itself, now have greater influence.