Ahmed Elghamaz

The clinical impact of contemporary stress echocardiography in morbid obesity for the assessment of coronary artery disease

Objective Non-invasive cardiac imaging may suffer from poor image quality in morbidly obese individuals. This study aimed to determine the clinical value of contemporary stress echocardiography (SE) in morbidly obese patients referred for assessment of suspected coronary artery disease (CAD). Methods This prospective, multicentre observational study was conducted in two district hospitals and one tertiary centre in London, UK. Individuals with body mass index ≥35 kg/m2 referred for SE were evaluated. The percentage of patients with obstructive CAD on coronary angiography, following abnormal SE, was assessed. Patient outcomes were determined with follow-up for the composite end-point of all-cause mortality, myocardial infarction and late revascularisation. Results Over a 13-month period, 209 morbidly obese patients underwent SE, and contrast agent was used in 96% of patients. A diagnostic result was obtained in 200/209 (96%) patients. Of 32 (15%) patients with inducible ischaemia, 25 underwent angiography, 22 (88%) had corresponding significant CAD and, of these, 16 (77%) underwent revascularisation. Conversely, only 2/157 patients (1.3%) with normal SE underwent angiography, and none underwent revascularisation. Over a mean follow-up period of 17.8±5.4 months, there were nine events. The annualised cardiac event rate after a normal SE was 0.95%. Events were more frequent in patients with inducible ischaemia versus those without ischaemia (5/32 (15.6%) vs 4/153 (2.6%); p=0.002). Ejection fraction <50% (HR 9.5; 95% CI 2.4 to 38.0; p=0.002) and inducible ischaemia (HR 9.4; 95% CI 2.5 to 35.8; p=0.001) were predictors of outcome on univariable Cox regression analysis. Conclusions Contemporary SE has excellent feasibility and positive predictive value and resulted in appropriate risk stratification of symptomatic patients with significant obesity. A normal SE portends an excellent outcome over the short–intermediate term in this high-risk patient population.

Exercise echocardiography in asymptomatic severe aortic stenosis

A 77 year old female with asymptomatic severe aortic stenosis (AS) and normal LV systolic function was referred for exercise stress echocardiography (ESE) in order to assess whether she is truly asymptomatic and to risk-stratify her aortic valve disease. While she only developed minimal breathlessness after 4.2 min of Bruce protocol and no other high risk features (arrhythmias, SBP drop, mean Aortic gradient rise [20 mmHg) [1], it was noted that her stroke volume (SV/ indexed SVi) and flow rate (FR) at peak stress had dropped compared to the ones at rest (SVi rest = 45.7 ml/m, SVi stress = 27 ml/m, FR rest = 234 ml/s, FR stress = 203 ml/ s). SV can drop physiologically during exercise due to reduction in ejection time [2]. However the drop in FR remained unexplained. This could be due to stress-induced myocardial dysfunction originating from global ischaemia due to AS or from myocardial ischaemia due to associated significant coronary artery disease (CAD). The patient had contrast ESE in order to assess for exercise induced LV dysfunction. This showed significant Regional Wall Thickening Abnormality in the left anterior descending (LAD) territory involving 9 out of 17 segments. She therefore underwent a coronary angiogram which confirmed features of tight proximal LAD disease (Fig. 1). Patient was referred for aortic valve replacement (AVR) and coronary artery bypass grafting. The above case highlights two important points. First that careful assessment of FR during ESE is crucial as FR reflects cardiac output. Secondly that the risk stratification of patients with asymptomatic severe AS using ESE should include assessment of regional wall thickening which may help to clarify the cause of exercise induced LV systolic dysfunction. The latter could be the result of ischaemia due to CAD and is a bad prognostic marker in severe AS.

115 Diagnostic concordance and clinical outcomes in patients undergoing fractional flow reserve and stress echocardiography for the assessment of coronary stenosis of intermediate severity

Introduction The ischaemic consequences of a coronary artery stenosis can be assessed by invasive fractional flow reserve (FFR) or by non-invasive imaging. We sought to determine (i) the concordance between wall thickening assessment and FFR during clinically indicated stress echocardiography (SE) and FFR measurements and (ii) the predictors of hard events in these patients. Methods and Results 194 patients who underwent SE and invasive FFR measurements in close succession were analysed for diagnostic concordance and clinical outcomes. At the vessel level, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of SE for identifying significant disease as assessed by FFR was 70%, 78%, 46% and 91% respectively. In patients with single vessel disease, the sensitivity, specificity, PPV and NPV were 86%, 66%, 38% and 95% respectively. The greatest discordance was seen in patients with wall thickening abnormalities (WTA) and negative FFR. During a follow up of 3.0±1.9 years there were 15 cardiovascular (CV) events. The number of wall segments with inducible WTAs emerged as the only independent predictor of CV events (HR 1.22 (1.05–1.43), p=0.01). FFR was not a predictor of outcome. There was a significant increase in event rate in patients with WTA/negative FFR and WTA/positive FFR, compared to patients with no WTA (p=0.04). However, no significant difference was seen between patients with WTA/negative FFR versus WTA/positive FFR (p=0.38) Conclusion In a patient population with significant CV risk factors, a normal SE effectively ruled out abnormal FFR. The greatest discordance was seen in patients with abnormal SE/normal FFR. In this group, patients had similar outcomes compared to those with abnormal SE/positive FFR but worse outcomes compared to patients with a normal SE. These findings have significant clinical implications.Abstract 115 Figure 1Abstract 115 Figure 2

TCT-540 Diagnostic Accuracy of Stress Echocardiography Compared With Invasive Coronary Angiography With Fractional Flow Reserve for the Diagnosis of Haemodynamically Significant Stenosis(Es) in Patients With Known or Suspected Coronary Artery Disease

TCT-539 Comparison between Instantaneous Wave-Free Ratio and Fractional Flow Reserve versus Morphometric Assessments by Intracoronary Imaging Devices Kensuke Matsushita, Kiyoshi Hibi, Kozo Okada, Yasushi Matsuzawa, Yuichiro Kimura, Nobuhiko Maejima, Noriaki Iwahashi, Anton Moritz, Toshiaki Ebina, Peter J. Fitzgerald, Yasuhiro Honda, Kazuo Kimura Yokohama City University Medical Center, Yokohama, Japan; Yokohama City University Medical Center, Yokohama, Japan; Stanford University, Stanford, California, United States; Vanderbilt University Medical Center; Medical Clinic III – Department of Nephrology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany; Medical Clinic III – Department of Nephrology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany; Medical Clinic III – Department of Nephrology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany; Division of Thoracic and Cardiovascular Surgery, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany; German Heart Center Munich; Division of Cardiovascular Medicine, Stanford University School of Medicine, Stanford, California, United States; Stanford University, Stanford, California, United States; Medical Clinic III – Department of Nephrology, University Hospital Frankfurt, Goethe University, Frankfurt am Main, Germany

132 Diagnostic Accuracy of Stress Echocardiography Compared with Invasive Coronary Angiography with Fractional Flow Reserve for The Diagnosis of Haemodynamically Significant Cad in Patients with Known or Suspected CAD

Introduction Haemodynamically significant coronary artery disease (CAD) is an important indication for revascularisation. Wall motion analysis during stress echocardiography (SE) is a noninvasive alternative to invasive fractional flow reserve (FFR) for evaluating hemodynamically significant CAD. We sought to determine the diagnostic accuracy of SE compared with invasive coronary angiography with FFR for the diagnosis of hemodynamically significant CAD. Methods and Results Between January 2008 and April 2015, all patients that underwent clinically indicated FFR measurements during invasive angiography and SE in close succession were analysed. Patients were excluded if tests were not done within 6 months of each other, or an intervening percutaneous coronary procedure or acute coronary syndrome occurred. 184 patients (mean age 66.5yrs, 59 (32%) female) were identified. The majority of patients underwent coronary angiography following SE. The prevalence of known CAD, diabetes and chronic kidney disease were 46%, 43% and 13% respectively, and 14 (8%) patients had previous coronary artery bypass surgery. Exercise SE was performed in 84 (46%) patients and Dobutamine SE in 100 (54%) patients. Contrast was used in 158 patients (86%). In 108 patients (59%), the SE was positive for inducible ischaemia. From 217 vessels analysed, the Left Anterior Descending Artery, Right Coronary Artery, Left Circumflex Artery and Left Main Coronary artery were involved in 120 (55%), 47 (22%), 30 (14%), 18 (8%) respectively, with 2 vessels being grafts. 46 FFR measurements were positive (21%) and 171 were negative (79%), using a cut off of≤ 0.80. At the vessel level, the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of SE for identifying significant disease as assessed by FFR was 70%, 77%, 45% and 90% respectively. In 73 patients, there was single vessel disease on angiography. At the vessel level, the sensitivity, specificity, PPV and NPV were 85%, 68%, 37% and 95%. Conclusion To date this is the largest study comparing SE and FFR for the assessment of the physiological significance of a coronary lesion, and reflects real world experience. SE demonstrates good diagnostic accuracy and excellent NPV for excluding flow-limiting disease. The low PPV is likely to represent the commencement of medical therapy following a positive SE, as well as referral bias (since only patients with positive SE underwent angiography) as well as the low prevalence of positive FFR measurements in this population. The presence of a haemodynamically significant stenosis can be accurately ruled out with SE.

Atrial enlargement associated with non-valvular atrial fibrillation: an unusual cause of dysphagia and weight loss

A 71-year-old woman presented with a 2-month history of intermittent solid dysphagia and weight loss of 7 kg. She reported no difficulty with swallowing liquids and also denied any anorexia, vomiting, nausea or change in voice. In addition, she had no change in bowel habit, jaundice or pale stools. Her medical history included paroxysmal atrial fibrillation and non-ischaemic dilated cardiomyopathy of 10-year duration, which was managed …

145 Stress Echocardiography Demonstrates Excellent Feasibility, Safety and Diagnostic Accuracy in Patients with Significant Obesity: First Results from the Stress Ultrasonography in Morbid Obesity (SUMO) Study

Background Significant obesity is an increasing global health problem. Obese individuals often have a clustering of cardiovascular risk factors such as hypertension, diabetes and dyslipidaemia. Thus, symptomatic patients often have a high pre-test probability of coronary artery disease (CAD) and are frequently referred for cardiac stress testing. These patients can provide significant technical challenges for imaging due to body habitus. The feasibility, safety and accuracy of stress echocardiography in patients with morbid obesity is unknown. Methods In this prospective multi-centre study, height, weight, body mass index (BMI) and body surface area (BSA) of all patients clinically referred for SE were measured. For patients with BMI >35, patient demographics and SE test results were also collected. The feasibility of SE was defined as the ability to perform and complete the test, achieving interpretable images for all three coronary artery territories. Agreement with angiography findings in patients subsequently referred for cardiac catheterization was also evaluated. Results Over an 11 month period across 3 hospitals, 2601 patients underwent SE, by 12 different operators, of whom 170 (6.5%) had BMI >35. Mean age was 59yrs, 44% were male and 25% had known CAD. Mean BMI was 39.5 and mean BSA was 2.2 m2. Dobutamine and exercise stress were performed in 60% and 40% respectively. Ultrasound contrast was used in 96% cases. There were no complications during the SE studies. SE demonstrated excellent feasibility, with a diagnostic test result achieved in 163/170 (96%) patients. Of the 7 patients with inconclusive SE, 2 were due to side-effects from dobutamine, 2 due to failure to reach target heart rate and 3 were due to poor image quality (thus just 3/170 [2%] due to poor image quality). Of 23 patients with inducible ischaemia, 19 proceeded to angiography and 17 had corresponding significant CAD (positive predictive value 89%). Conclusions SE demonstrates excellent feasibility, safety and positive predictive value in real-world clinical practice in patients with morbid obesity. These results are clinically pertinent given the increasing proportion of such patients sent for non-invasive testing. Follow-up of this cohort to delineate event-free survival will reveal the accuracy of risk stratification of SE in this high-risk population.

Asymptomatic giant coronary artery aneurysms: images from coronary angiography, IVUS, and echocardiography.

The incidence of coronary aneurysms varies from 1.5% to 5% of cases at angiography [(1)][1]. The primary complications are ischemia and infarction due to thrombosis or dissection. Spontaneous rupture is rare. The presence of coronary aneurysms, with or without obstructive disease, is an independent