Functional Assessment of Myocardial Bridging With Conventional and Diastolic Fractional Flow Reserve: Vasodilator Versus Inotropic Provocation.

Background Functional assessment of myocardial bridging (MB) remains clinically challenging because of the dynamic nature of the extravascular coronary compression with a certain degree of intraluminal coronary reduction. The aim of our study was to assess performance and diagnostic value of diastolic-fractional flow reserve (d-FFR) during dobutamine provocation versus conventional-FFR during adenosine provocation with exercise-induced myocardial ischemia as reference. Methods and Results This prospective study includes 60 symptomatic patients (45 men, mean age 57±9 years) with MB on the left anterior descending artery and systolic compression ≥50% diameter stenosis. Patients were evaluated by exercise stress-echocardiography test, and both conventional-FFR and d-FFR in the distal segment of left anterior descending artery during intravenous infusion of adenosine (140 µg/kg per minute) and dobutamine (10-50 µg/kg per minute), separately. Exercise-stress-echocardiography test was positive for myocardial ischemia in 19/60 patients (32%). Conventional-FFR during adenosine and peak dobutamine had similar values (0.84±0.04 versus 0.84±0.06, P=0.852), but d-FFR during peak dobutamine was significantly lower than d-FFR during adenosine (0.76±0.08 versus 0.79±0.08, P=0.018). Diastolic-FFR during peak dobutamine was significantly lower in the exercise-stress-echocardiography test -positive group compared with the exercise- stress-echocardiography test -negative group (0.70±0.07 versus 0.79±0.06, P<0.001), but not during adenosine (0.79±0.07 versus 0.78±0.09, P=0.613). Among physiological indices, d-FFR during peak dobutamine was the only independent predictor of functionally significant MB (odds ratio, 0.870; 95% CI, 0.767-0.986, P=0.03). Receiver-operating characteristics curve analysis identifies the optimal d-FFR during peak dobutamine cut-off ≤0.76 (area under curve, 0.927; 95% CI, 0.833-1.000; P<0.001) with a sensitivity, specificity, and positive and negative predictive value of 95%, 95%, 90%, and 98%, respectively, for identifying MB associated with stress-induced ischemia. Conclusions Diastolic-FFR, but not conventional-FFR, during inotropic stimulation with high-dose dobutamine, in comparison to vasodilatation with adenosine, provides more reliable functional significance of MB in relation to stress-induced myocardial ischemia.

Coronary Flow Velocity Reserve Using Dobutamine Test for Noninvasive Functional Assessment of Myocardial Bridging.

BACKGROUND: It has been shown that coronary flow velocity reserve (CFVR) measurement by transthoracic Doppler echocardiography (TTDE) during dobutamine (DOB) provocation provides a more accurate functional evaluation of myocardial bridging (MB) compared to adenosine. However; the cut-off value of CFVR during DOB for identification of MB associated with myocardial ischemia has not been fully clarified. PURPOSE: This prospective study aimed to determine the cut-off value of TTDE-CFVR during DOB in patients with isolated-MB, as compared with stress-induced wall motion abnormalities (VMA) during exercise stress-echocardiography (SE) as reference. METHODS: Eighty-one symptomatic patients (55 males [68%], mean age 56 ± 10 years; range: 27-74 years) with the existence of isolated-MB on the left anterior descending artery (LAD) and systolic MB-compression ≥50% diameter stenosis (DS) were eligible to participate in the study. Each patient underwent treadmill exercise-SE, invasive coronary angiography, and TTDE-CFVR measurements in the distal segment of LAD during DOB infusion (DOB: 10-40 µg/kg/min). Using quantitative coronary angiography, both minimal luminal diameter (MLD) and percent DS at MB-site at end-systole and end-diastole were determined. RESULTS: Stress-induced myocardial ischemia with the occurrence of WMA was found in 23 patients (28%). CFVR during peak DOB was significantly lower in the SE-positive group compared with the SE-negative group (1.94 ± 0.16 vs. 2.78 ± 0.53; p < 0.001). ROC analyses identified the optimal CFVR cut-off value ≤ 2.1 obtained during high-dose dobutamine (>20 µg/kg/min) for the identification of MB associated with stress-induced WMA, with a sensitivity, specificity, positive and negative predictive value of 96%, 95%, 88%, and 98%, respectively (AUC 0.986; 95% CI: 0.967-1.000; p < 0.001). Multivariate logistic regression analysis revealed that MLD and percent DS, both at end-diastole, were the only independent predictors of ischemic CFVR values ≤2.1 (OR: 0.023; 95% CI: 0.001-0.534; p = 0.019; OR: 1.147; 95% CI: 1.042-1.263; p = 0.005; respectively). CONCLUSIONS: Noninvasive CFVR during dobutamine provocation appears to be an additional and important noninvasive tool to determine the functional severity of isolated-MB. A transthoracic CFVR cut-off ≤2.1 measured at a high-dobutamine dose may be adequate for detecting myocardial ischemia in patients with isolated-MB.

Endothelial cell markers from clinician's perspective.

Endothelial cell markers are membrane-bound or cytoplasmic molecules expressed by endothelial cells, which help their easier identification and discrimination from other cell types. During vasculogenesis, endothelial cells differentiate from hemangioblasts to form new blood vessels. With the discovery of endothelial progenitor cells (EPC) and their ability to form new blood vessels, the term vasculogenesis is not only reserved for the embryonic development. Possibility of de novo blood vessel formation from EPC is now widely explored in different ischemic conditions, especially in cardiovascular medicine. Numerous clinical trials have tested enhancing tissue vascularization by delivering hematopoietic cells that expressed endothelial markers. This therapeutic approach proved to be challenging and promising, particularly for patients who have exhausted all conventional therapeutic modalities. Angiogenesis, which refers to the formation of new blood vessels from existing vasculature, is indispensable process during tumor progression and metastasis. Blockage of tumor angiogenesis by targeting and inhibiting endothelial cell has emerged as novel safe and efficacious method to control many advanced malignant diseases. Numerous clinical studies are currently testing new antiangiogenic drugs which target and inhibit endothelial cell markers, receptors or molecules which transmit receptor-mediated signals, therefore inhibiting endothelial cell proliferation, migration and vascular tube formation. Many of these drugs are now widely used in clinical settings as first- or second-line chemotherapy in advanced malignant conditions. So far, these therapeutic approaches gave modest, yet encouraging clinical improvements, prolonging survival and improving functional capacity and quality of life for many terminally ill patients. Here we present the most commonly used endothelial cell markers along with their applicability in contemporary clinical practice.

Noninvasive assessment of myocardial bridging by coronary flow velocity reserve with transthoracic Doppler echocardiography: vasodilator vs. inotropic stimulation.

BACKGROUND: To consider hemodynamic assessment of myocardial bridging (MB) adequate, it is believed that inotropic stimulation with dobutamine should be estimated because its dynamic nature depends on the degree of extravascular coronary compression. This study evaluated comparative assessment of hemodynamic relevance of MB using coronary flow velocity reserve (CFVR) measurements by transthoracic Doppler echocardiography (TTDE) with vasodilatative and inotropic challenges. METHODS: This prospective study included forty-four patients with angiographic evidence of isolated MB of the left anterior descending coronary artery (LAD) and systolic compression of ≥50% diameter stenosis. All patients were evaluated by exercise stress-echocardiography (ExSE) test for signs of myocardial ischemia, and CFVR of the distal segment of LAD during iv.infusion of adenosine (ADO:140µg/kg/min) and iv.infusion of dobutamine (DOB:10-40µg/kg/min), separately. RESULTS: Exercise-SE was positive for myocardial ischemia in 8/44 (18%) of patients. CFVR during ADO was significantly higher than CFVR during peak DOB (2.85±0.68 vs. 2.44±0.48, p=0.002). CFVR during peak DOB was significantly lower in SE-positive group in comparison to SE-negative group (2.01±0.16 vs. 2.54±0.47, p<0.001), but not for ADO (2.47±0.51 vs. 2.89±0.70, p=0.168), respectively. Multivariable logistic analysis showed that CFVR peak DOB was the most significant predictor of functional significant MB (OR 0.011, 95%CI: 0.001-0.507, p=0.021). Receiver-operating characteristic curves have shown that TTDE-CFVR obtained by high-dose of dobutamine infusion is better than those by adenosine regarding to functional status of MB (AUC 0.861, p=0.004; AUC 0.674, p=0.179, respectively). CONCLUSIONS: Non-invasive CFVR measurement by TTDE during inotropic stimulation, in comparison to vasodilation, provides more reliable functional evaluation of MB.

Regional differences among female patients with heart failure from the Cardiac Insufficiency BIsoprolol Study in ELDerly (CIBIS-ELD).

BACKGROUND: The aim of our study was to examine regional differences in the demographics, etiology, risk factors, comorbidities and treatment of female patients with heart failure (HF) in the Cardiac Insufficiency BIsoprolol Study in ELDerly (CIBIS-ELD) clinical trial. METHODS AND RESULTS: One hundred and fifty-nine female patients from Germany and 169 from Southeastern (SE) Europe (Serbia, Slovenia and Montenegro) were included in this subanalysis of the CIBIS-ELD trial. Women comprised 54% of the study population in Germany and 29% in SE Europe. German patients were significantly older. The leading cause of HF was arterial hypertension in German patients, 71.7% of whom had a preserved ejection fraction. The leading etiology in SE Europe was the coronary artery disease; 67.6% of these patients had a reduced left ventricular ejection fraction (34.64 ± 7.75%). No significant differences were found in the prevalence of traditional cardiovascular risk factors between the two regions (hypertension, diabetes, hypercholesterolemia, smoking and family history of myocardial infarction). Depression, chronic obstructive pulmonary disease and malignancies were the comorbidities that were noted more frequently in the German patients, while the patients from SE Europe had a lower glomerular filtration rate. Compared with the German HF patients, the females in SE Europe received significantly more angiotensin converting enzyme inhibitors, loop diuretics and less frequently angiotensin receptor blockers and mineralocorticoid receptor antagonists. CONCLUSIONS: Significant regional differences were noted in the etiology, comorbidities and treatment of female patients with HF despite similar risk factors. Such differences should be considered in the design and implementation of future clinical trials, especially as women remain underrepresented in large trial populations.

Primary percutaneous coronary intervention in a patient with right internal mammary artery graft originating from arteria lusoria dextra.

INTRODUCTION: Congenital aomalies of the aortic arch, although numerous and heterogeneous, occur in less than 1% of individuals at autopsies. Left aortic arch with an aberrant right subclavian artery, also called arteria lusoria dextra, is the most common anomaly of the aortic arch, occurring in 0.5-2.5% of individuals. CASE OUTLINE: We report the case of a 48-year-old man suffering from acute inferoposterior-wall ST elevation myocardial infarction successfully treated by primary percutaneous coronary intervention.Ten years ago, the patient had undergone coronary artery bypass graft surgery with the implantation of two arterial grafts- left and right internal mammary arteries on both left anterior descending and right coronary artery. After several attempts to canulate truncus brachiocephalicus, angiogram revealed the left aortic arch with the aberrant right subclavian artery. To our knowledge, this is the first described case of primary percutaneous coronary intervention via the aberrant right subclavian artery and right internal mammary artery graft with stent implantation in the infarct related lesion of the distal segment of right coronary artery. Subsequent 64-multidetector computed tomography confirmed the angiographic findings. CONCLUSION: Early recognition of congenital anomalies of the aortic arch and its great vessels, even before coronary artery bypass graft surgery, could be crucial for the urgent and successful treatment of patients with life-threatening conditions, such as ST segment elevation myocardial infarction.

Stenting and surgery for coronary vasospasm : the wrong solution fails to solve the problem.

A 55-year-old man, with a history of medically uncontrolled coronary vasospasm, presented for evaluation of chest pain 6 months after implantation of left internal mammary artery. Due to recurrent episodes of vasospastic angina and serious complications of coronary spasm (ventricular fibrillation, myocardial infarction), a stent had previously been implanted in the proximal part of left anterior descending artery at the site of angiographically and ergonovine-proven coronary spasm, with subsequent in-stent restenosis.

Heart failure caused by cardiac rhabdomyosarcoma.

Rhabdomyosarcoma accounts for 20% of primary malignant cardiac tumours. We describe a woman with cardiac rhabdomyosarcoma. She had loss of appetite, loss of weight, and symptoms of heart failure. A mobile tumour in the left atrium, entering the left ventricle during diastole, was detected by transthoracic echocardiography. The tumour was removed surgically in total; histological diagnosis was rhabdomyosarcoma; however, the patient died after 6 months. In conclusion, primary malignant cardiac tumours can simulate heart failure or systemic disorders. Cardiac rhabdomyosarcomas have a poor prognosis with average survival of 6 months after diagnosis.