Four-dimensional echocardiography area strain combined with exercise stress echocardiography to evaluate left ventricular regional systolic function in patients with mild single vessel coronary artery stenosis

BACKGROUND

The aim of this prospective study was to assess the diagnosis value of four-dimensional echocardiography area strain (AS) combined with exercise stress echocardiography to evaluate left ventricular regional systolic function in patients with mild single vessel coronary artery stenosis.

METHODS

Based on treadmill exercise load status, two-dimensional conventional echocardiography and four-dimensional echocardiography area strain were performed on patients suspected coronary artery disease before coronary angiogram. Thirty patients (case group) with mild left anterior descending coronary artery stenosis (stenosis <50%) and thirty gender- and age-matched patients (control group) without coronary artery stenosis according to the coronary angiogram results were prospectively enrolled.

RESULTS

All the patients had no left ventricular regional wall motion abnormality in two-dimensional echocardiography at rest and exercise stress. There was no significant difference in the 16 segmental systolic peak AS at rest between two groups. After exercise stress, the peak systolic AS_rest-stress at mid anterior wall (-7.00%±10.90% vs 2.80%±23.69%) and mid anterolateral wall (-4.40%±18.81% vs 8.80%±19.16%) were decreased, while increased at basal inferolateral wall (14.00%±19.27% vs -5.60%±15.94%) in case group compared with control group (P<.05).

CONCLUSIONS

In patients with mild single vessel coronary artery stenosis, the area strain was decreased at involved segments, while compensatory increased at noninvolved segments after exercise stress. Four-dimensional echocardiography area strain combined with exercise stress echocardiography could sensitively find left ventricular regional systolic function abnormality in patients with mild single vessel coronary artery stenosis, and locate stenosis coronary artery accordingly.

[Clinical value of apolipoprotein B versus low-density lipoprotein cholesterol in assessing risks of coronary artery disease]

OBJECTIVE

To compare the value of apolipoprotein B (apoB) and low-density lipoprotein cholesterol (LDL-C) in assessing the risk of coronary heart disease in patients with inconsistent apoB and LDL-C levels.

METHODS

In a total of 603 patients undergoing coronary angiography, apoB and LDL-C levels were categorized into high and low levels relative to the median levels of apoB and LDL-C, based on which the patients were divided into 4 groups with low apoB/low LDL-C, low apoB/high LDL-C, high apoB/low LDL-C, or high apoB/high LDL-C. According to the results of coronary angiography, we evaluated the number of coronary artery branches with lesions and the severity of coronary artery stenosis in the 4 groups to assess the correlation of apoB and LDL-C with cardiovascular risks.

RESULTS

We found significant differences in the number of coronary artery branches with lesions and the severity of coronary artery stenosis among the 4 groups (P<0.05). The number of coronary artery branches involved and the severity of stenosis differed significantly between patients with consistently high and low apoB/LDL-C levels (P<0.005). Compared with those with low apoB/low LDL-C levels, the patients with high apoB/low LDL-C levels showed a significantly greater number of coronary artery branches with lesions (P=0.017) and more severe stenosis (P=0.034), but such differences were not found in patients with low apoB/high LDL-C levels. Pearson correlation analysis identified LDL-C and apoB as the risk factors for cardiovascular disease with areas under the ROC curve of 0.579 (P=0.014) and 0.589 (P=0.006), respectively.

CONCLUSIONS

In patients with inconsistent levels of apoB and LDL-C, apoB and LDL-C levels are both risk factors of coronary heart disease in close relation with the disease severity. LDL-C and apoB are comparable for their important values in predicting the risk of coronary heart disease.

Detection of Hemodynamically Significant Coronary Artery Stenosis With CT Enhancement Ratio: A Validation Study in a Porcine Model

OBJECTIVE

Although numerous techniques that are based on CT number analysis have been proposed, the assessment of hemodynamically significant coronary artery stenosis remains a great challenge. The purpose of this study is to validate use of the CT enhancement ratio in the detection of hemodynamically significant coronary artery stenosis in a porcine model.

MATERIALS AND METHODS

Experiments involving eight closed-chest swine were performed. A balloon catheter was placed into the left anterior descending coronary artery to simulate different degrees of luminal stenosis. The myocardial blood flow (MBF) ratio was measured using the colored microsphere technique. The fractional flow reserve was measured using an invasive pressure wire. CT scans were performed during the first-pass phase, while the pigs were undergoing adenosine stress tests. The CT enhancement ratio and the CT attenuation ratio were calculated using data from the CT images obtained.

RESULTS

Results suggested that the CT enhancement ratio had a strong correlation (y = 0.07245 + 0.09963x; r² = 0.898; p < 0.001) with the MBF ratio measured using the microsphere technique, whereas only moderate correlation (y = -1.5508 + 2.2684x; r² = 0.498; p < 0.001) was noted between the CT attenuation ratio and the MBF ratio measured using the microsphere technique. In ROC curve analysis, the AUC values of the CT enhancement ratio and the CT attenuation ratio were 0.927 and 0.829, respectively, with regard to the detection of significant ischemia during adenosine stress tests, as defined by the fractional flow reserve.

CONCLUSION

The CT enhancement ratio provides a reliable prediction of the MBF ratio measured using the microsphere technique, indicating that this metric has good diagnostic performance in the detection of hemodynamically significant coronary artery stenosis. The CT enhancement ratio may have potential for use as an imaging biomarker for the relative quantitative assessment of myocardial perfusion.

Non-diagnostic coronary artery calcification and stenosis: a correlation of coronary computed tomography angiography and invasive coronary angiography

Background Heavy coronary artery calcification (CAC) impairs diagnostic accuracy of coronary computed tomography angiography (cCTA) and is considered to be a major limitation. Purpose To investigate the effect of non-evaluable CAC seen on cCTA on clinical decision-making by determining the degree of subsequent invasive testing and to assess the relationship between non-evaluable segments containing CAC and significant stenosis as seen in invasive coronary angiography (ICA). Material and Methods The study comprised of 356 patients who underwent cCTA and subsequent ICA within 2 months between 2005 and 2009. Clinical reports were reviewed to identify the indications for referral to ICA. In a subset of 68 patients where non-diagnostic CAC on cCTA and significant stenosis on ICA were present in the same segment, we correlated and analyzed the underlying stenosis severity of the lesion on ICA to the cCTA. Lesions with CAC were analyzed in a standardized fashion by application of reading rules. Results Non-diagnostic CAC on cCTA prompted ICA in 5.6% of patients. CAC occurred at the site of maximum stenosis in segments with stenosis <50% (95.9% [47/49]), 50-69% (82.4% [28/34]), 70-99% (64.5% [31/48]), and 100% (33.3% [1/3]). At the point of maximum calcium deposit, non-obstructive disease was present in 61.2%. Application of reading rules resulted in a 44% reduction in non-diagnostic cCTA reads. Conclusion Severe CAC may prompt further investigation with ICA. There is less CAC with increasing lesion severity at the point of maximum stenosis. Additional application of reading rules improved non-diagnostic cCTA reads.

Influence of Coronary Artery Diameter on Intracoronary Transluminal Attenuation Gradient During CT Angiography

OBJECTIVES

The goal of this study was to assess the effect of coronary artery diameter on luminal attenuation and the correlation between the transluminal attenuation gradient (TAG) and transluminal diameter gradient (TDG) on computed tomography (CT) coronary angiography.

BACKGROUND

Recent studies have reported promising results of TAG in detecting significant stenosis. However, because of the intrinsic nature of CT reconstruction algorithms, luminal attenuation may be affected by vessel diameter.

METHODS

In this 3-part study, phantom simulating vessels of various diameters immersed in different contrast mixtures were scanned, and intraluminal attenuations were measured. In addition, dynamic volume CT scanning was performed in 3 mongrel dogs (untreated, a stenosis model, and an occlusion model) using 320-row area detector computed tomography and intraluminal attenuations, and TAGs were calculated at each temporal scan and compared. In a separate clinical study, TAGs and TDGs of 152 coronary arteries from 62 patients who underwent 320-row area detector computed tomography coronary angiography and invasive angiography were measured and compared.

RESULTS

Intraluminal attenuation of phantom vessels gradually decreased along with a decrease in diameter. Animal studies revealed that the peak attenuation of distal smaller coronary arteries did not reach that of proximal larger coronary arteries: 55.2% to 78.1% peak attenuation of proximal coronary arteries. No differences in TAG were found between stenotic and normal left circumflex arteries at temporal scans (all, p > 0.05). The clinical study demonstrated significant correlation between TAG and TDG (r = 0.580; p < 0.0001).

CONCLUSIONS

Intraluminal attenuation was shown to decrease with diminution of vessel diameters. In addition, TAG exhibited a significant correlation with TDG, implying that TAG may be a secondary result because of differences in diameters.

Chronological changes in stenosis of translocated coronary arteries on angiography after the arterial switch operation in children with transposition of the great arteries: comparison of myocardial scintigraphy and angiographic findings

BACKGROUND

The peri-operative mortality of the arterial switch operation in neonates with transposition of the great arteries is considerably low; however, long-term outcomes of translocated coronary arteries still remain one of the most crucial issues. Methods and results A total of 110 neonates with transposition of the great arteries after arterial switch operation were evaluated; three (2.7%) late deaths occurred. The remaining 107 patients except for one underwent follow-up angiography. Angiography showed coronary artery stenosis in nine (8.4%), with right coronary artery lesions in two and left main trunk lesions in seven. In two patients, right coronary artery stenosis regressed during follow-up. In left main trunk lesions, the severity of stenosis improved in four, did not change in one, and progressed to total occlusion in two patients. In children with coronary artery stenosis, myocardial scintigraphy showed perfusion defects in five out of six (83%) with left main trunk with ⩾75% stenosis and in four out of four with left main trunk stenosis ⩾90%. In contrast, patients whose coronary artery stenosis disappeared during follow-up had no perfusion defects on scintigraphy.

CONCLUSIONS

Regression of ostial stenosis of the transplanted coronary artery on angiogram was observed. The stenosis regressed over time in six patients; two coronary arteries with 99% stenosis and delayed angiographic enhancement of the distal coronary artery resulted in total occlusion within 1 year after the arterial switch operation. Combination of angiography and myocardial scintigraphy could be useful to differentiate deceptive stenosis from progressive stenosis.

Red Cell Distribution Width Can Predict the Significance of Angiographically Intermediate Coronary Lesions

OBJECTIVE

In the present study, the association between red cell distribution width (RDW) with functional significance of intermediate coronary artery lesions was investigated.

MATERIALS AND METHODS

Two hundred and forty-six consecutive patients, 168 males and 78 females, who underwent fractional flow reserve (FFR) measurement for angiographically intermediate coronary stenosis (40-70% in quantitative coronary analysis) in the left anterior descending coronary artery were enrolled into the study. The functional significance of intermediate coronary artery lesions was determined by FFR measurement. An FFR value <0.75 was defined as functionally significant. Venous blood samples were taken within 48 h before the FFR measurement, and RDW levels were determined by a Coulter LH Series hematology analyzer. Logistic regression analysis was used to examine the association between functional significance in FFR measurement and other variables.

RESULTS

Of the 246 patients, 62 (25.2%) exhibited significant functional stenosis (FFR <0.75) in the FFR measurement. The mean RDW level was significantly higher in patients with significant stenosis (14.19 ± 0.73 vs. 13.69 ± 0.77, p < 0.001). In stepwise multivariate logistic regression analysis, RDW (OR = 2.489, 95% CI = 1.631-3.799, p < 0.001) and male gender (OR = 2.826, 95% CI = 1.347-5.928, p = 0.006) were independent predictors of significant functional stenosis.

CONCLUSION

Increased RDW levels were associated with functional significance of angiographically intermediate coronary artery stenoses.

Correlation between mimecan expression and coronary artery stenosis in patients with coronary heart disease

OBJECTIVE

This study aimed to investigate the correlation between coronary artery stenosis and Mimecan expression in patients with coronary heart disease (CHD).

METHODS

Seventy eight patients with CHD and 80 controls without vascular lesions were recruited into present study. CHD patients were divided into one-vessel CHD subgroup, 2-vessel CHD subgroup and multivessel CHD subgroup. ELISA was performed to detect the expressions of serum Mimecan and nuclear factor kappaB (NF-κB).

RESULTS

When compared with control group, the expressions of serum mimecan gene and NF-κB significantly increased in CHD groups (P < 0.05); When compared with one-vessel and two-vessel CHD subgroups, the expressions of serum mimecan and NF-κB significantly increased in multivessel CHD subgroup (P < 0.05), significant difference was observed among three subgroups (P < 0.05). The expressions of serum mimecan and NF-κB were positively related to the severity of coronary lesions (rmimecan=0.79, rNF-κB=0.83, P < 0.05).

CONCLUSION

Increased expressions of serum mimecan and NF-κB in CHD patients are related to cardiac insufficiency, which may be ascribed to the binding of NF-κB to mimecan gene.

A review of adherence to the guidelines for coronary CT angiography quantitative stenosis grading thresholds in published research

BACKGROUND

The degree of coronary stenosis of potential hemodynamic significance is central to the interpretation of coronary computed tomography angiography (CCTA), but has been variably defined in the literature. Societal guidelines have attempted to address this issue via recommended thresholds.

OBJECTIVES

We surveyed the various thresholds for defining significant coronary stenosis reported in research published since the introduction of the Society for Cardiovascular Computed Tomography guidelines regarding the interpretation and reporting of CCTA.

METHODS

We systematically reviewed the results of bibliographic searches of all original research articles on CCTA, focusing on studies reporting > 25 subjects, to assess the definitions of severity of coronary lesions as found on CCTA. To enable comparisons, we stratified the methods of reporting lesion severity into ≥ 50%, 50% to 69%, and "others" (including infrequent reporting methods).

RESULTS

Fifty-nine11 published studies were identified and met inclusion criteria. Eighteen studies reported the severity of coronary stenosis using a definition of 50% to 69% as moderate stenosis; 35 studies defined ≥ 50% coronary stenosis as "stenosis," "significant stenosis," or "obstructive lesion" without distinguishing a threshold for moderate versus severe stenosis. Six studies utilized other thresholds, such as 20% to 75%, 40% to 69%, 40% to 70%, 40% to 79%, and 50% to 75% to define moderate coronary stenosis.

CONCLUSIONS

Fifty-three of 59 studies were graded in accordance with the recommended threshold of ≥ 50% defining potentially significant stenosis, with 18 studies reporting precisely in accordance with the guidelines-recommended thresholds of ≥ 50% narrowing as defining moderate stenosis and ≥ 70% narrowing as defining severe stenosis. Six studies were reported using alternative thresholds for significant stenosis. However, a majority of research studies published since 2009 do not follow the societal guidelines for stenosis grading, since these studies do not clearly describe the degree of coronary stenosis.

Cardiac MRI for myocardial ischemia

Proper assessment of the physiologic impact of coronary artery stenosis on the LV myocardium can affect patient prognosis and treatment decisions. Cardiac magnetic resonance imaging (CMR) assesses myocardial perfusion by imaging the myocardium during a first-pass transit of an intravenous gadolinium bolus, with spatial and temporal resolution substantially higher than nuclear myocardial perfusion imaging. Coupled with late gadolinium enhancement (LGE) imaging for infarction during the same imaging session, CMR with vasodilating stress perfusion imaging can qualitatively and quantitatively assess the myocardial extent of hypoperfusion from coronary stenosis independent of infarcted myocardium. This approach has been validated experimentally, and multiple clinical trials have established its diagnostic robustness when compared to stress single-photon emission computed tomography. In specialized centers, dobutamine stress CMR has been shown to have incremental diagnostic value above stress echocardiography due to its high imaging quality and ability to image the heart with no restriction of imaging window. This paper reviews the technical aspects, diagnostic utility, prognostic values, challenges to clinical adaptation, and future developments of stress CMR imaging.

Correlation between single nucleotide polymorphisms of the ACTA2 gene and coronary artery stenosis in patients with type 2 diabetes mellitus

This study aimed to analyze the correlation between single nucleotide polymorphisms (SNPs) of the actin, aortic smooth muscle (ACTA2) gene and coronary artery stenosis in patients with type 2 diabetes mellitus (T2DM). Eight SNPs from the promoter region of the ACTA2 gene were screened. Patients with T2DM (n=251) were divided into two groups, those with severe coronary stenosis (SCS⁺ group; n=168) and those without severe coronary stenosis (SCS⁻ group; n=83). Patients were also divided according to lesion branching into those whose lesions involved less than three branches (LCA⁻ group) and those whose lesions involved at least three branches (LCA⁺ group). The clinical and laboratory data of the patients were collected, and the genotyping of eight SNPs was conducted followed by statistical analysis. Of the eight SNPs, only the rs1324551 SNP was identified to be significantly different between the SCS⁺ and SCS⁻ groups (P<0.05). The frequency of the rs1324551 G allele and GG genotype in the SCS⁺ group was significantly higher than that of the SCS⁻ group (P=0.044 and P=0.001, respectively). No significant difference was observed between the LCA⁻ and LCA⁺ groups. Following the deduction of age, gender and traditional risk factors, the odds ratios of the GG genotype in additive and recessive models were 2.93 [95% confidence interval (CI), 1.05–8.19; P=0.04] and 2.34 (95% CI, 1.09–5.02; P=0.03), respectively, and this relevancy was represented only in patients with low insulin levels. Age and smoking were also found to increase the risk of coronary artery lesions. In conclusion, the rs1324551 SNP in the promoter region of the ACTA2 gene was identified to be independently correlated with the degree of coronary artery stenosis in patients with T2DM and plasma insulin may inhibit coronary artery stenosis during the pathogenic process.

Diagnostic performance evaluation of a computer-aided simple triage system for coronary CT angiography in patients with intermediate risk for acute coronary syndrome

RATIONALE AND OBJECTIVES

Given the significance of coronary artery disease as the most important socioeconomic health care problem in the Western World, the application of computer-aided simple triage (CAST) systems to this disease would be desirable.

MATERIALS AND METHODS

In total, 93 patients with acute chest pain and an intermediate risk score for acute coronary syndrome underwent coronary computed tomography angiography (cCTA). Among those, 74 were of adequate image quality for automated analysis by a commercially available CAST system (COR Analyzer, RCADIA, Haifa, Israel). CAST findings were compared to human expert interpretation for the detection of significant stenosis (≥50%) in the left main, left anterior descending, circumflex, right coronary artery, or arterial branches. Further, one inexperienced observer evaluated all studies for significant stenoses alone and after 1 month guided by a CAST system as an initial read.

RESULTS

Human expert interpretation identified 37/74 patients with stenosis ≥50%, whereas the CAST detected 45 patients. The CAST system demonstrated a sensitivity of 100%/79% and a specificity of 78%/89% on a per-patient/per-vessel level, respectively. With CAST, the inexperienced readers' per-vessel sensitivity and positive predictive values significantly improved (P = .011, P = .009) from 69% and 41% to 91% and 74%, respectively.

CONCLUSIONS

The investigated CAST system for automatic stenosis detection can accurately identify patients with coronary artery stenosis ≥50% and may be of use as initial interpretation and triage of cCTA studies as well as a second reader for inexperienced readers, in absence of expert readers.

Correlation between the severity of periodontitis and coronary artery stenosis in a Chinese population

BACKGROUND

The aim of this study was to evaluate the relationship between the severity of periodontitis and the extent and degree of coronary artery stenosis in a Chinese population.

METHODS

Patients (n = 853) with coronary artery stenosis confirmed by coronary angiography were eligible to take part in the study. Only subjects that were ≥60 years old, had ≥50% stenosis in at least one coronary artery, and did not have diabetes or a history of smoking were included (n = 115). After periodontal examination, including bleeding index, probing depth calculus index, plaque index and periodontal attachment loss, four groups were defined based on the severity of periodontitis: no periodontitis/gingivitis (M0, n = 19); mild periodontitis (M1, n = 27); moderate periodontitis (M2, n = 31); and severe periodontitis (M3, n = 38). The extent and degree of coronary artery stenosis was obtained by calculating the Gensini score (GS).

RESULTS

The GS was significantly greater in the M3 group compared with the M0 group. Multiple linear regression analysis revealed that probing depth and plaque index were significantly correlated with the GS.

CONCLUSIONS

The extent and severity of coronary artery stenosis in Chinese patients ≥60 years old is positively correlated with the severity of periodontitis.

Evaluation of coronary steal in myocardium supplied by coronary collaterals: the role of speckle tracking analysis in resting and stress echocardiography

Coronary steal could develop in patients with chronic coronary artery disease (CAD) with collateral circulation, and adversely affect ventricular function and long-term clinical outcome. Poorly developed collaterals are more prone than well-developed collaterals to withdrawing their blood support to the collateralized myocardium due to higher collateral pathway resistance and lower vasodilatory reserve of the collateral bed. Even with well-developed coronary collaterals, coronary steal could still occur when perfusion pressure in the donor artery becomes low, or the recipient microvasculature is maximally dilated with exhaustion of vasodilatory reserve. The evaluation of distinctive coronary collateral function with or without steal provides important therapeutic and prognostic information in patients with chronic CAD. However, due to lack of reliable assessment methods, the detection and quantitative measurement of coronary steal remains a challenge. In this article, we present typical clinical scenarios to illustrate the major mechanisms underlying coronary steal in patients with chronic CAD and coronary collateral circulation, and review invasive and noninvasive methods currently available to assess coronary steal in myocardium supplied by coronary collaterals. We specifically focus on recent advances in the resting and stress echocardiography with speckle tracking techniques.

Acute Right Coronary Ostial Stenosis during Aortic Valve Replacement

We report a rare case of acute right coronary artery stenosis developing in a patient undergoing aortic valve replacement. We present a case report with a brief overview of the literature relating to coronary artery occlusion associated with cardiac valve surgery - the theories and treatments are discussed. A 85 year-old female was admitted under the care of the cardiothoracic team with signs and symptoms of heart failure. Investigations, including cardiac echocardiography and coronary angiography, indicated a critical aortic valve stenosis. Intraoperative right ventricular failure ensued post aortic valve replacement. Subsequent investigations revealed an acute occlusion of the proximal right coronary artery with resultant absence of distal flow supplying the right ventricle. An immediate right coronary artery bypass procedure was performed with resolution of the right ventricular failure. Subsequent weaning off cardiopulmonary bypass was uneventful and the patient continued to make excellent recovery in the postoperative phase. To our knowledge this is one of the few documented cases of intraoperative acute coronary artery occlusion developing during valve surgery. However, surgeons should be aware of the potential for acute occlusion so that early recognition and rapid intervention can be instituted.

Virtual Interventions for Image-based Blood Flow Computation

Image-based blood flow computation provides great promise for evaluation of vascular devices and assessment of surgical procedures. However, many previous studies employ idealized arterial and device models or only patient-specific models from the image data after device deployment, since the tools for model construction are unavailable or limited and tedious to use. Moreover, in contrast to retrospective studies from existing data, there is a pressing need for prospective analysis with the goal of surgical planning. Therefore, it is necessary to construct models with deployed devices in a fast, virtual and interactive fashion. The goal of this paper is to develop new geometric methods to deploy stents or stent grafts virtually to patient-specific geometric models constructed from a 3D segmentation of medical images. A triangular surface representing the vessel lumen boundary is extracted from the segmentation. The diseased portion is either clipped and replaced by the surface of a deployed device or rerouted in the case of a bypass graft. For diseased arteries close to bifurcations, bifurcated device models are generated. A method to map a 2D strut pattern on the surface of a device is also presented. We demonstrate three applications of our methods in personalized surgical planning for aortic aneurysms, aortic coarctation, and coronary artery stenosis using blood flow computation. Our approach enables prospective model construction and may help to expand the throughput required by routine clinical uses in the future.

Detection of severe left anterior descending coronary artery stenosis by transthoracic evaluation of resting coronary flow velocity dynamics

In the presence of severe stenosis, coronary artery flow may be reduced at rest. Recent advances in echocardiography have made non-invasive sampling of velocities in the left anterior descending coronary artery (LAD) possible. The aim of our study was to evaluate feasibility and capability of transthoracic Doppler to detect severe stenosis of the LAD. The study population consisted of 42 subjects with suspected coronary artery disease scheduled for coronary angiography. All had complete transthoracic echocardiography and Doppler sampling of LAD velocities. Quantitative coronary angiography was performed within 24 hours of the echocardiogram. Correlations between LAD velocity profile, measurements and calculations, and the angiographic results were performed. Six subjects had LAD occlusion, 10 had severe (>80% diameter) LAD stenosis, and 26 had normal or non-occlusive LAD disease. In all six subjects with LAD occlusion, distal LAD velocities were not detectable, while in the other 36 subjects, LAD velocities were recorded indicating the vessels were patent. In the 10 subjects with severe LAD stenosis, the diastolic/systolic velocity ratio was <1.5, while in those with non-significant LAD disease, the diastolic/systolic velocity ratio was >1.5 (P<0.005). Diastolic LAD flow was 21.8±13 mL/min in the presence of severe stenosis as compared to 48.5±20 mL/min in subjects without severe stenosis (P<0.0013). LAD velocities had high sensitivity and specificity for the prediction of severe angiographic stenosis. Thus transthoracic Doppler measurement of LAD velocities is feasible and can predict the presence of severe LAD stenosis or occlusion.

The burden of angina pectoris and its complications [corrected]

Between 10 to 30% of patients with coronary disease still suffer from symptoms of angina pectoris in contemporary clinical practice. This article summarizes analytic tools for measuring angina, as well as, its prevalence based on community based surveys, registries and in randomized controlled trials. Additionally, the impact of angina symptoms on patients' survival rates, functional status, quality of life and health-related costs is reviewed. The effectiveness of treatment, revascularization and medical therapies, on reducing angina symptoms is also reviewed.