Differential coronary artery calcification detected by electron beam computed tomography as an indicator of coronary stenosis among patients with stable angina pectoris.

BACKGROUND: The detection of coronary artery calcification by electron beam computed tomography (EBCT) has been suggested as an indicator of atherosclerosis and coronary artery disease (CAD). There is no consensus on the correlation between coronary calcification and angiographically significant stenosis on an artery-by-artery basis. OBJECTIVE: To examine the relationship between coronary calcification score (CCS) and the presence of significant CAD on an artery-by-artery basis in patients with stable angina pectoris. METHODS AND RESULTS: EBCT and coronary angiogram (CAG) were evaluated in 71 patients with stable angina and in nine control subjects. The CCSs of each of the four major coronary arteries were highest in patients with significant CAD (n=43), followed by patients with insignificant CAD (n=5), patients with syndrome X (n=23) and control subjects, respectively. Calcification scores of the four major coronary arteries appeared to have different predictive power for significant stenosis on the same vessel. For left main (LM) and left anterior descending (LAD) coronary arteries, CCSs of vessels with significant stenoses were not different from those without significant stenoses (values expressed as medians: LM 0 versus 1; LAD 98.5 versus 70; not significant). Calcification scores of left circumflex (LCX) and right coronary arteries (RCA) were significantly higher in vessels with significant stenosis (LCX 49.5 versus 0; RCA 53 versus 1; P<0.05). CCSs appeared to be moderately useful to predict significant stenoses in these two vessels (areas under receiver operating characteristic curves: LCX 0.68+/-0.08, 95% CI 0.52 to 0.81; RCA 0.71+/-0.08, 95% CI 0.55 to 0.84). CONCLUSIONS: The CCSs of RCA and LCX arteries, but not those of LM and LAD arteries, may predict significant angiographic stenosis on an artery-by-artery basis among patients with stable angina pectoris.     

Coronary artery size in North Indian population – Intravascular ultrasound-based study

ObjectiveThe coronary artery dimensions have important diagnostic and therapeutic implications in management of coronary artery disease (CAD). There is paucity of data on the coronary artery size in the Indian population as measured by intravascular ultrasound (IVUS).MethodsA total of 303 patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI) with intravascular ultrasound underwent analysis along with quantitative coronary angiography (QCA). Of the 492 proximal coronary segments; 221 relating to left main (LM), 164 to left anterior descending artery (LAD), 45 to left circumflex artery (LCX), and 62 to right coronary artery (RCA) were considered.ResultsPatient's mean age was 53.37 ± 3.5 years; men 80%; hypertension 35% and diabetes 24.8%. On IVUS, mean minimal lumen diameter as compared to QCA in LM (4.60 mm versus 4.50 mm, p < 0.001), LAD (3.71 mm versus 3.45 mm, p < 0.001), LCX (3.55 mm versus 3.16 mm, p < 0.001) and RCA (3.85 mm versus 3.27 mm, p < 0.001) were significantly larger. Lumen and external elastic membrane (EEM) cross-sectional area (CSA) were larger in males as compared to females with statistical significance for lumen CSA in LM (p = 0.04); RCA (p = 0.02) and EEM CSA in LM (p = 0.03); RCA (p = 0.006) but no significance for adjusted body surface area (BSA). In multivariate models, BSA and age were independent predictors of LM and LAD diameters and areas, but age was an independent predictor indexed to BSA.ConclusionThe coronary artery dimensions by IVUS are significantly larger than QCA. No gender difference in coronary artery size. Age was an independent predictor of coronary artery size in left main and LAD. The coronary artery size may not be a risk factor for acute coronary syndrome.     

Significance of exercise-induced ST changes in leads aVR,V5, and V1. Discrimination of patients with single- or multivessel coronary artery disease

BACKGROUND: It is known that exercise-induced ST-segment elevation in lead V1 (V1-E) detects left anterior descending (LAD) stenosis. It was also postulated that ST elevation in aVR and simultaneous ST depression in V5 (aVR-E + V5-D) is a marker of ischemia due to significant stenosis of the LAD in patients with single-vessel disease. HYPOTHESIS: This study was undertaken to investigate the significance of the concomitant appearance of both electrocardiographic (ECG) ischemic markers, and of each of them alone during exercise, to detect either LAD stenosis as single-vessel coronary artery disease (CAD), or multivessel CAD involving LAD stenosis. METHODS: A total of 196 consecutive patients (152 men and 44 women, mean age 54 +/- 7 years) with at least one of these ECG markers, who underwent treadmill exercise testing with the Bruce protocol and coronary arteriography, were studied. RESULTS: Patients were divided into three groups. In Group A (83 patients with V1-E + aVR-E & V5-D), 93% of patients with single-vessel disease had significant LAD stenosis (p<0.001), whereas 75% of patients with double-vessel disease had significant stenoses of the LAD and the left circumflex (LCx) coronary arteries (p<0.01). In Group B (97 patients with aVR-E & V5-D but without V1-E), 43% of patients with single-vessel disease had significant LAD stenosis (p<0.08), whereas 85% of patients with double-vessel disease had significant stenoses of the LAD and the right coronary artery (RCA) (p<0.01). In Group C (16 patients with only V1-E), 60% of patients with single-vessel disease had significant LAD stenosis (p<0.05), whereas 75% of patients with double-vessel disease had significant LAD and LCx stenoses (p<0.05). CONCLUSIONS: The concomitant appearance of exercise-induced ST elevation in lead V1, ST elevation in lead aVR, and ST depression in lead V5, as well as the isolated appearance of ST elevation in lead V1 detect significant LAD stenosis as single-vessel disease, or significant stenoses of LAD and LCx arteries in patients with double-vessel disease, whereas the appearance of ST elevation in aVR & ST depression in V5 but without ST elevation in V1 correlates strongly with significant LAD and RCA stenoses and usually indicates double-vessel disease.     

Myocardial Contrast Echocardiography in Assessment of Stable Coronary Artery Disease at Intermediate Dobutamine-Induced Stress Level

Background: Myocardial contrast stress echocardiography (stress MCE) is a novel method for diagnosing coronary artery disease (CAD). Few studies have compared the diagnosis of ischemia by stress MCE to angiographic CAD. Methods: Dobutamine stress MCE and SonoVue contrast infusion were performed before an elective percutaneous coronary intervention in 37 patients (8 women) aged 45–75 years with symptomatic CAD and at least one significant coronary artery stenosis measured by quantitative coronary angiography (QCA). The total and regional perfusion and wall motion (WM) were scored as normal or abnormal and attributed to the three main epicardial coronary arteries using a 17-segment left ventricular model. Results: An intermediate stress level was obtained in 29 (78%) patients, and 2 (5%) patients obtained peak stress. A perfusion defect was detected in 92% and WM abnormality in 57% of the patients at peak stress (P < 0.01). By perfusion, 70% of stenoses were both detected and correctly anatomically located, compared to 42% by WM (P < 0.01). All 21 patients with multivessel disease and/or proximal left anterior descending (LAD) stenosis measured by QCA were identified by stress-induced perfusion defects, while only 11 of them were identified by WM abnormalities (P < 0.01). Conclusion: Perfusion scoring is superior to WM scoring during stress MCE for diagnosing significant CAD in patients obtaining intermediate stress level, in particular, when multivessel disease or proximal LAD stenosis is present.     

PCI in a case of dual (type IV) LAD with anomalous origin of the LCx from RCA

Dual left anterior descending coronary artery (LAD) originating from the left main stem and the right coronary artery (type IV LAD) is a rare congenital anomaly. Its association with an anomalous origin of the left circumflex (LCx) from RCA is even rarer.We describe a patient presenting with acute inferior wall myocardial infarction, who was subsequently found to have this coronary anomaly. He underwent staged PCI of the dominant RCA and anomalous LCx successfully through the radial route.We conclude that anomalous coronaries can be safely and successfully treated through the radial route after careful evaluation of origin and course of the anomalous vessels. CT coronary angiography is extremely useful in delineating the vessel course and particularly their relation to great arteries.     

右冠状动脉病变对左冠状动脉狭窄患者左心室功能的影响

目的　探讨右冠状动脉病变对左冠状动脉狭窄患者左心室功能的影响及其机制。方法　对比分析左冠状动脉狭窄患者在合并与不合并右冠状动脉病变时的左心室射血分数。结果　与相应部位单纯左冠状动脉狭窄患者相比 ,合并右冠状动脉病变患者左心室射血分数均呈不同程度地下降 ,其中在左前降支、左前降支 +左回旋支狭窄基础上合并右冠状动脉病变时左心室射血分数下降有统计学意义 (P <0 .0 5或 0 .0 1) ,左主干合并右冠状动脉狭窄患者下降幅度最大 ,但无统计学意义。结论　右冠状动脉病变可在单纯左冠状动脉狭窄的基础上使左心室收缩功能进一步恶化 ;当左冠状动脉狭窄部位为左前降支、左主干或左前降支 +左回旋支时 ,对左心室收缩功能影响更为严重     

右冠状动脉狭窄程度对左冠状动脉狭窄患者左室射血分数的影响

目的研究右冠状动脉不同程度狭窄对左冠状动脉狭窄患者左室射血分数（LVEF）的影响。方法根据左冠状动脉病变部位不同,将1 000例左冠状动脉狭窄患者分为左前降支（LAD）狭窄,左回旋支（LCX）狭窄,左主干（LM）狭窄,左前降支+左回旋支（LAD+LCX）狭窄4个系列。每个系列再根据右冠状动脉（RCA）病变程度不同分为RCA正常组（直径狭窄<50%）、RCA非闭塞组（99%>直径狭窄≥50%）和RCA闭塞组（直径狭窄≥99%）,比较分析3组间LVEF的差异。结果在LAD,LCX,LM,LAD+LCX狭窄时,与RCA正常组LVEF相比,RCA非闭塞组LVEF分别下降0.9%,0.3%,3.4%和2.8%;RCA闭塞组LVEF分别下降10.9%,3.7%,6.5%和5.2%。LAD狭窄时,RCA非闭塞组和RCA闭塞组之间LVEF有统计学差异（P<0.01）。结论右冠状动脉病变可在左冠状动脉狭窄的基础上使左室射血分数进一步下降;当左冠状动脉狭窄为闭塞性病变时,影响更为明显。     

iMAP™ imaging of tumorous lesions surrounding the coronary arteries in a patient with an elevated serum level of immunoglobulin G4

A 76-year-old woman with multiple coronary risk factors was admitted to our hospital because of episodes of new-onset chest pain that had begun 3 days previously. She underwent percutaneous coronary intervention (PCI) for severe stenoses in the two high lateral (HL) branches. Intravascular ultrasound (IVUS) revealed massive stenotic lesions in the HL branches and tumorous nonstenotic lesions in the left anterior descending coronary artery (LAD) and the left circumflex coronary artery (LCx). iMAP?, optical coherence tomography (OCT), and coronary computed tomography angiography (CCTA) were performed. iMAP depicted fibrosis in the vessel (green areas) and nonfibrotic tissue change suggestive of inflammation outside the vessel (yellow/red areas). OCT revealed high-intensity homogenous intimal hyperplasia with superficial calcification, and CCTA showed massive periarterial soft lesions in the HL, LAD, and LCx. The serum IgG4 level was high at 252–427 mg/dL (8 measurements) (reference range, 4.8–105.0 mg/dL). We suspected IgG4-related coronary periarteritis on the basis of the comprehensive diagnostic criteria as a possible diagnosis. The clinical course was good after initial and subsequent PCIs for both the HL stenoses and the progressing LCx stenosis, and there was no recurrence of angina pectoris thereafter. Steroids were not administered because the massive lesions did not enlarge during the 16 months of follow-up. iMAP was able to evaluate the tissue characteristics of tumorous lesions in the stenosed HL branches and the nonstenotic LAD and LCx in a patient with an elevated level of IgG4.     

Wandering coronary stenoses: Adrenaline‐induced coronary artery spasm in a patient resuscitated from cardiac arrest

A 68‐year‐old ex‐smoker man with history of allergy, presented to the emergency department with progressive dyspnea one hour following self‐medication with aspirin for troublesome headache. Examination revealed diffuse sibilant rhonchi over both lungs. Electrocardiogram showed signs of ischemia. In the intensive care unit, he received bronchodilators, nitroglycerin, and aspirin. Bronchospasm increased, and then the patient was shocked, and developed cardiac arrest. After resuscitation, he was kept on mechanical ventilation and adrenaline infusion. He was sceduled for coronary angiography. The left system demonstrated stenosis of the mid‐segment of the left anterior descending artery (LAD), which was totally occluded distally, stenosis of the left circumflex (LCx) with a mild plaque in its marginal branch. The right system demonstrated stenosis of the mid‐segment of the right coronary artery (RCA), with diffusely diseased posterior descending artery (PDA) and posterolateral left ventricular branch (PLLV). Successful direct stenting was performed to the RCA. Angiography demonstrated worsening of the distal stenosis in the PLLV and complete occlusion of the PDA. Balloon dilatation of the PLLV was adequate, but dilatation of the PDA failed. Repeat angiography of the left system revealed an occluded LCx with critical stenosis of its marginal branch; nevertheless, the LAD was as before. Balloon dilatation of the distal LAD was attempted without improvement, yet, angiography therein, demonstrated “migration” of the stenoses in the LCx. The procedure was halted, adrenaline infusion discontinued, and an intra‐aortic balloon pump inserted. The patient was discharged one day later. Follow‐up angiography 6 months later demonstrated mild atherosclerotic coronary irregularities. © 2010 Wiley‐Liss, Inc.     

Hybrid coronary revascularization for the treatment of left main coronary stenosis: a feasibility study

Objective : To determine the feasibility of a hybrid coronary revascularization (HCR) approach for the treatment of left main (LM) coronary artery stenosis. Background : The recommended therapy for significant LM stenosis is coronary artery bypass grafting (CABG). Percutaneous coronary intervention (PCI) of unprotected LM lesions is reserved for patients at high risk for complications with CABG. HCR in LM disease has not been studied. Methods : Twenty‐two consecutive patients with LM stenosis >70% underwent staged HCR. Following a robotic or thoracoscopic‐assisted minimally invasive left internal mammary artery (LIMA) to left anterior descending artery (LAD) coronary bypass, PCI of the LM, and non‐LAD targets was performed after angiographic confirmation of LIMA patency. Intravascular ultrasound confirmed optimal stent deployment. Thirty‐day adverse outcomes and long term follow up was obtained. Results : In the 22 patients with LM lesions, 6 were ostial, 5 mid, and 11 distal. LIMA patency was FitzGibbon A in all cases. LM stenting was successful in all patients with drug‐eluting stents (DES) placed in 21 of 22 cases. Three patients underwent stent implantation in the right coronary artery. There were no 30‐day major adverse cardiac or cerebrovascular events. At a mean of 38.8 ± 22 months postprocedure, 21 patients were alive without reintervention; one death occurred at 454 days. Conclusions : HCR for LM coronary disease is a feasible alternative to CABG and unprotected LM PCI. This approach combines the long‐term durability of a LIMA‐LAD bypass with the less invasive option of PCI in non‐LAD targets with DES. © 2011 Wiley Periodicals, Inc.     

Indicators of the maximum radiation dose to the skin during percutaneous coronary intervention in different target vessels.

OBJECTIVES: To evaluate whether the maximum radiation dose to the patient's skin (MSD) can be estimated during percutaneous coronary intervention (PCI) procedures, we investigated the relationship between the MSD and fluoroscopic time, dose-area product (DAP), and body weight, separately analyzing the relationships for different target vessels. BACKGROUND: Many cases of skin injury caused by excessive radiation exposure during cardiac intervention procedures have been reported. However, real-time maximum-dose monitoring of the skin is unavailable for many cardiac intervention procedures. METHODS: We studied 197 consecutive PCI procedures that involved a single target vessel and were conducted. The DAP was measured, and the MSD was calculated by a skin-dose mapping software program (Caregraph). The target vessels of the PCI procedures were divided into four groups based on the AHA classification system: AHA 5-10, left anterior descending artery domain (LAD), AHA 11-15, left circumflex artery domain (LCx), AHA 1-3 = R 1-3, and AHA 4 = R 4. RESULTS: The correlation coefficient (r) between the MSD and fluoroscopic time was higher for the right coronary artery (RCA) vessels (R 1-3, 0.852; R 4, 0.715) than for the left coronary artery (LCA) vessels (LAD, 0.527; LCx, 0.646), and the r value between the MSD and DAP was higher for the RCA vessels (R 1-3, 0.871; R 4, 0.898) than for the LCA vessels (LAD, 0.628; LCx, 0.694). Similarly, the correlation coefficient between the MSD and weight x fluoroscopic time (WFP) was higher for the RCA vessels (R 1-3, 0.874; R 4, 0.807) than for the LCA vessels (LAD, 0.551; LCx, 0.735). CONCLUSIONS: The DAP and WFP can be used to estimate the MSD during PCI in the RCA but not in the LCA, especially the LAD.     

The diameter of coronary artery is enlarged in patients with dilated cardiomyopathy

Background Dilated cardiomyopathy(DCM) is a primary cardiomyopathy characterized by the enlargement of left ventricle or biventricular and left ventricular systolic dysfunction, without any obvious stenosis of coronary arteries. However, it remains unclear that whether the diameter of coronary artery is different from those of normal population, because few studies directly assessed the diameter of the coronary artery in patients with DCM. The study aimed to evaluate the diameter of coronary arteries in DCM patients and its influence on prognosis for DCM patients. Methods Fifty-seven DCM patients and fifty-nine patients presenting with atypical chest pain and normal coronary angiography were enrolled in the study. A coronary angiography image analysis system was used to measure the diameters at 5 mm from the opening of the left main coronary artery(LM), left anterior descending(LAD) and left circumflex coronary(LCX) arteries, and the right coronary artery(RCA) of both groups. Follow-up study through telephone over a period of 2 years was performed. Spearman rank correlation and logistic regression were used to evaluate the correlations of the diameter of coronary arteries with the risk of nonfatal heart failure event. Results Diameters of the LM, LAD, LCX, and RCA in DCM group were significantly larger than those of the control group(P 0.001). During a follow-up of 2 years, the nonfatal heart failure event occurred in 9 patients of DCM group, but not in control group. Spearman rank correlation analysis showed diameters of the LM, LAD, and LCX were correlated with the risk of nonfatal heart failure event, respectively(P 0.05). While the diameter of RCA showed no correlation with the risk of nonfatal heart failure event(P =0.583). Whereas logistic regression analysis showed there were no correlation between diameters of the LM,LAD, LCX, and RCA and the risk of nonfatal heart failure event(P 0.05). Conclusions The coronary arteries of DCM patients show a larger diameter without any obvious stenosis, which may not correlate with the risk of heart failure event.     

Percutaneous Coronary Intervention for Chronic Total Occlusion in Single Coronary Arteries

We retrospectively compared the results of percutaneous coronary intervention (PCI) and optimal medical therapy (OMT) for chronic total occlusion (CTO) in single coronary arteries to determine whether outcomes depend on the artery involved.From January 2004 through November 2015, a total of 731 patients were treated at our center for CTO in the left anterior descending coronary artery (LAD) (234 patients, 32%), left circumflex coronary artery (LCx) (184, 25.2%), or right coronary artery (RCA) (313, 42.8%). We further classified patients by treatment (PCI or OMT) and compared the cumulative incidence of major adverse cardiac events (MACE) and the composite of total death or myocardial infarction, as well as change in left ventricular ejection fraction from baseline.The 5-year cumulative incidence of MACE was similar between the treatment groups regardless of target vessel. The 5-year cumulative incidence of the composite of total death or myocardial infarction was significantly lower after PCI than after OMT or failed PCI in the LCx (2.6% vs 11.5%; P=0.020; log-rank) and RCA (5.8% vs 17.2%; P=0.002) groups, but not in the LAD group. Cox proportional hazards regression analysis indicated that PCI independently predicted a lower incidence of the composite of total death or myocardial infarction in the LCx group (hazard ratio [HR]=0.184; 95% CI, 0.0035–0.972; P=0.046) and the RCA group (HR=0.316; 95% CI, 0.119–0.839; P=0.021).The artery involved does not appear to affect clinical outcomes of successful PCI for single-vessel CTO. Further investigation in a randomized clinical trial is warranted.     

Comparison of synchrotron radiation angiography with conventional angiography for the diagnosis of in-stent restenosis after percutaneous transluminal coronary angioplasty.

AIMS: Synchrotron radiation angiography (SRA) is a novel tool for minimally invasive coronary artery imaging. The method uses subtraction of two images produced at energies bracketing the iodine K-edge after intravenous infusion of iodinated contrast agent. We investigated the accuracy of SRA for detecting in-stent restenosis (ISR). METHODS AND RESULTS: We recruited 57 men, 4-6 months after successful PTCA. We visualized the right coronary artery (RCA) in 27 patients with 36 stented segments [12 segments with ISR>50% by quantitative coronary angiography (QCA)], and the left anterior descending artery (LAD) in 30 patients with 37 stented segments (10 ISR). SRA and QCA were performed within 2 days of each other. Two experienced observers unaware of QCA data evaluated the SRA results. Image quality was good or excellent in most patients. Global sensitivity was 64%, specificity was 95%, and positive and negative predictive values were approximately 85%. Inter-observer kappa concordance coefficient was 0.86. False negatives involved short eccentric lesions and superimposed segments, most frequently of the LAD. False positives occurred in intermediate stenoses slightly overestimated by SRA. CONCLUSION: In men, this minimally invasive approach, using small radiation doses, detects significant ISR in the RCA, but the LAD poses difficulties because of superimposition with others structures.     

Acute myocardial infarction and underlying stenosis severity.

OBJECTIVES: The objective of this study was to investigate the underlying stenosis severity of the culprit lesion in acute myocardial infarction. BACKGROUND: It is widely believed that myocardial infarction often occurs in angiographically mild luminal stenosis. This, however, is in contradiction with experience from interventional practice in primary PCI. METHODS: We performed quantitative coronary angiography (QCA) in 250 consecutive patients referred for acute percutaneous coronary intervention (PCI) because of acute myocardial infarction (AMI). Fundamental for analysis was that a realistic estimate of underlying luminal narrowing before the infarction could be made angiographically that QCA could be performed and that one of two criteria was met: (1) spontaneous reflow allowing assessment of the lumen proximal and distal to the culprit lesion, or (2) coronary artery closed at arrival but reflow after uncomplicated wiring allowing assessment of the lumen proximal and distal to the culprit lesion. RESULTS: Of 250 consecutive patients (mean age 61.7 +/- 12.7 years, 48 women) referred for acute PCI, 156 patients (62%) fulfilled at least one of the above criteria for reliable QCA. In 151 of these patients (96%) the severity of the underlying stenosis was >50% and in 103 (66%) it was >70%. There were no differences in stenosis severity between the left anterior descending [LAD, (72 +/- 13)%, n = 57], left circumflex [Cx, (74 +/- 10)%, n = 20], and right coronary artery territory [RCA, (74 +/- 12)%, n = 76] (ANOVA, P = 0.76). There were no differences in stenosis severity between women [(73 +/- 13)%, n = 36] and men [(75 +/- 11)%, n = 120; P = 0.35]. CONCLUSION: In contrast to what is often believed, the majority of myocardial infarctions occurs in significant stenosis.     

Contrast enhanced multi-detector computed tomography coronary angiography versus conventional invasive quantitative coronary angiography in acute coronary syndrome patients-correlation and bias

BACKGROUND: Previous studies that compared multi-detector computed tomography (MDCT) non-invasive coronary angiography with conventional coronary angiography, did not assessed the ability of MDCT to detect stenotic lesions correctly in acute coronary syndromes (ACS) patients. The aim of the present study was to assess prospectively the correlation and bias between 16-slice MDCT coronary angiography and quantitative coronary angiography analysis (QCA) in these patients. METHODS: Patients underwent electrocardiogram-gated, 16-slice MDCT coronary angiography and routine invasive percutaneous coronary angiography with quantitative coronary angiography (QCA) analysis blinded to MDCT results. The correlation and the bias between the results of MDCT and QCA were assessed in segments observed by both modalities in vessels > or = 2 mm in diameter. RESULTS: 59 patients (81% male, age 56 +/- 11 years), admitted due to ACS, underwent MDCT and invasive coronary angiography. 544 segments were analyzed. The correlations between MDCT and QCA observed for the left anterior descending coronary artery (LAD), the left circumflex coronary artery (Cx), the right coronary artery (RCA) and for all analyzed segments were 0.74 (P < 0.0001), 0.54 (P < 0.009), 0.72 (P < 0.0001) and 0.70 (P < 0.0001), respectively. By Bland-Altman analysis, a small overestimation of the lesion severity with MDCT of 4.8% for the LAD, 5.9% for the Cx, and 3.3% for the RCA was observed. CONCLUSIONS: In ACS patients, MDCT contrast-enhanced coronary angiography provides good quantification of the luminal diameter as compared to coronary angiography, and it is characterized by a small overestimation bias.     

Effect of ischemia on implantable defibrillator intracardiac shock electrograms

Introduction: Few attempts have been made to extract information from the ventricular electrogram (EGM) recorded by implantable cardioverter defibrillators (ICD) aside from the discrimination of supraventricular tachycardia and ventricular tachycardia. The current study aims to examine the effect of ischemia in the major coronary artery distributions on the shock EGM from ICDs.
Methods: Domestic crossbred pigs (n = 10, 20–40 kg) were implanted with a dual-coil right ventricular defibrillation system. Through the femoral approach, percutaneous balloon occlusion of the major coronary arteries was performed. The left anterior descending (LAD), left circumflex (LCx), and right coronary (RCA) arteries were occluded in random order for 3–5 minutes with 30-minute periods of reperfusion in between and the shock EGMs were recorded and analyzed.
Results: During peak ischemia, R wave amplitude increased by a mean of 204.3% (P = 0.003), increased by a mean of 73.8% (P = 0.0009), and decreased by a mean of 28.0% (P = 0.109) in the LAD, LCx, and RCA territories, respectively. During peak ischemia ST segments elevated by a mean of 105.3% (P = 0.041), elevated by a mean of 114.9% (P = 0.064), and decreased by a mean of 584.5% (P = 0.006) in the LAD, LCx, and RCA territories, respectively.
Conclusions: Ischemia affects ICD shock EGMs in a manner that appears to vary depending on the culprit vessel. Our data demonstrate the feasibility of ischemia detection from ICD shock EGMs.     

Fractional flow reserve assessment to determine the indications for myocardial revascularisation in patients with borderline stenosis of the left main coronary artery

INTRODUCTION: Reliable assessment of clinical significance of borderline angiographic lesions found within the left main coronary artery (LM) is often impossible. Measurement of fractional flow reserve (FFR) is commonly used to verify borderline stenoses of the coronary arteries. However, the usefulness of FFR measurements has been validated only for arteries other than the LM. AIM: Evaluation of the measured FFR value in determination of the indications for myocardial revascularisation in borderline LM stenosis. METHODS: The study involved 38 patients aged 55+/-9 years (range 41-74 years) with isolated borderline LM stenosis. Each patient had the measurement of FFR performed during intravenous adenosine infusion at a dose of 140 microg/kg/min. Patients were referred for revascularisation if FFR was <0.75. RESULTS: The mean LM stenosis in quantitative coronary angiography (QCA) was 45+/-10%. FFR<0.75 was found in 18 (47%) patients, whereas 20 (53%) subjects had FFR < or =0.75. In subjects with FFR <0.75 QCA showed significantly lower minimal lumen diameters (MLD) at the site of stenosis (1.84+/-0.45 vs 2.24+/-0.49, p=0.014). Additionally, a significant correlation was found between FFR and MLD (r=0.59, p<0.001). The mean clinical follow-up was 2 years (range 1-3 years). There were two (11%) fatal events in patients with FFR < or =0.75 who underwent CABG. One (5%) patient with FFR >0.75 underwent elective CABG due to progression of LMN stenosis. Moreover, one (5%) patient experienced myocardial infarction not related to borderline stenosis of the LM. CONCLUSIONS: The measurement of FFR confirms the clinical significance of stenosis only in half of the patients with borderline isolated lesion of the left main coronary artery. Withdrawal from intervention in patients with FFR > or =0.75 is safe and is associated with favourable clinical outcomes in two-year follow-up.     

One-year follow-up after intravascular ultrasound assessment of moderate left main coronary artery disease in patients with ambiguous angiograms.

OBJECTIVES: The purpose of this study was to correlate angiographic and intravascular ultrasound (IVUS) findings in left main coronary artery (LMCA) disease and identify the predictors of coronary events at one year in patients with LMCA stenoses. BACKGROUND: Significant (> or =50% diameter stenosis [DS]) LMCA disease has a poor long-term prognosis. METHODS: One hundred twenty-two patients who underwent angiographic and IVUS assessment of the severity of LMCA disease and who did not have subsequent catheter or surgical intervention were followed for one year. Standard clinical, angiographic and IVUS parameters were collected. RESULTS: The quantitative coronary angiography (QCA) reference diameter (3.91 +/- 0.76 mm, mean +/- 1 SD) correlated moderately with IVUS (4.25 +/- 0.78 mm, r = 0.492, p = 0.0001). The lesion site minimum lumen diameter (MLD) (2.26 +/- 0.82 mm) by QCA correlated less well with IVUS (2.8 +/- 0.82 mm, r = 0.364, p = 0.0005). The QCA DS measured 42 +/- 16%. During the follow-up period, 4 patients died, none had a myocardial infarction, 3 underwent catheter-based LMCA intervention and 11 underwent bypass surgery. Univariate predictors of events (p < 0.05) were diabetes, presence of another lesion whether treated with catheter-based intervention or untreated with DS > 50% and IVUS reference plaque burden and lesion lumen area, maximum lumen diameter, MLD, plaque area and area stenosis. Using logistic regression analysis diabetes mellitus, an untreated vessel (with a DS > 50%) and IVUS MLD were independent predictors of cardiac events. CONCLUSIONS: In selected patients assessed by IVUS, moderate LMCA disease had a one-year event rate of only 14%. Intravascular ultrasound MLD was the most important quantitative predictor of cardiac events. For any given MLD, the event rate was exaggerated in the presence of diabetes or another untreated lesion (>50% DS).     

Dobutamine stress echocardiography as a predictor of coronary lesion severity on coronary angiography.

In order to evaluate the capacity of dobutamine stress echocardiography (stress echo) to predict the severity of atherosclerotic lesions observed on coronary angiography in patients with coronary artery disease, we performed a retrospective study at Instituto Nacional de Cardiologia and Universidade Federal Fluminense, Brazil. The health records of 40 patients who underwent both stress echo and coronary angiography within a period of less than 14 days were assessed. For the stress echo analysis, the heart was divided into 16 segments and the different types of response assessed: biphasic, ischemic, viable or unchanged. The main arteries - left anterior descending artery (LAD), left circumflex coronary artery (LCx) and right coronary artery (RCA) and their branches - were studied by coronary angiography to assess the degree of obstruction (in %), the type of lesion (A, B1, B2 or C), and the presence or absence of collateral circulation. The following results were obtained: patients showing an altered response on stress echo (ischemic) presented a higher degree of coronary obstruction as well as more complex lesions in the anterior descending artery on coronary angiography. A higher degree of obstruction was associated with more complex lesions (in LAD, LCx and RCA) and collateral circulation (in LAD and RCA). The presence of more complex lesions also correlated with collateral circulation in the LAD. Based on these results, we concluded that dobutamine stress echocardiography is a non-invasive test capable of predicting the severity of coronary lesions in patients with chronic ischemic cardiopathy.