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.

Prognostic Value of Preserved Coronary Flow Velocity Reserve by Noninvasive Transthoracic Doppler Echocardiography in Patients With Angiographically Intermediate Left Main Stenosis.

BACKGROUND: The potential of angiography to evaluate the hemodynamic severity of a left main coronary artery (LM) stenosis is limited. Noninvasive transthoracic Doppler echocardiographic coronary flow velocity reserve (CFVR) evaluation of intermediate coronary stenosis has demonstrated remarkably high negative prognostic value. The aim of this study was to assess clinical outcomes in patients with angiographically intermediate LM stenosis and preserved CFVR (>2.0) as evaluated by transthoracic Doppler echocardiographic CFVR. METHODS: The initial study population included 102 patients with intermediate coronary stenosis of the LM referred for transthoracic Doppler echocardiographic CFVR assessment. Peak diastolic CFVR measurements were performed in the distal segment of the left anterior descending coronary artery after intravenous adenosine (140 µg/kg/min), and CFVR was calculated as the ratio between maximal hyperemic and baseline coronary flow velocity. Nineteen patients had impaired CFVR (≤2.0) and were excluded from further analysis, as well as two patients with poor acoustic windows. The final group consisted of 81 patients (mean age, 60 ± 9 years; 76 men) evaluated for adverse cardiac events including death, myocardial infarction, and revascularization. RESULTS: Mean follow-up duration was 62 ± 26 months. Mean CFVR was 2.4 ± 0.4. Total event-free survival was 75 of 81 (92.6%), as six patients were referred for revascularization (five patients with coronary artery bypass grafting, one patient with percutaneous coronary intervention). There were no documented myocardial infarctions or cardiovascular deaths in the follow-up period. CONCLUSIONS: In patients with angiographically intermediate and equivocal LM stenosis and preserved CFVR values of >2.0, revascularization can be safely deferred.

Novel Assessment Tool For Coronary Artery Disease Severity During Screening Mammography.

Breast arterial calcifications (BACs) are common findings on mammography which are associated with an increased risk of the coronary artery disease (CAD). Our aim in the current study was to design measurement instruments of CAD prediction, with or without BACs, and its discriminatory validity in the diagnosis of CAD (expressed by Syntax score) in women. This was observational, prospective study in the women cohort which underwent mammography and angiography. In this study we have demonstrated that the total 'The Breast Arterial Calcification and Coronary Artery Disease Scale' (BACCADS) was good additional diagnostic tool for detection of patients with severe CAD.

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.

Functional recovery of patients with ischemic cardiomyopathy treated with coronary artery bypass surgery and concomitant intramyocardial bone marrow mononuclear cell implantation--a long-term follow-up study.

BACKGROUND/AIM: Intramyocardial bone marrow mononuclear cells (BMMNC) implantation concomitant to coronary artery bypass grafting (CABG) surgery as an option for regenerative therapy in chronic ischemic heart failure was tested in a very few number of studies, with not consistent conclusions regarding improvement in left ventricular function, and with a follow-up period between 6 months and 1 year. This study was focused on testing of the hypothesis that intramyocardial BMMNC implantation, concomitant to CABG surgery in ischemic cardiomyopathy patients, leads to better postoperative long-term results regarding the primary end-point of conditional status-functional capacity and the secondary endpoint of mortality than CABG surgery alone in a median follow-up period of 5 years. METHODS: A total of 30 patients with ischemic cardiomyopathy and the median left venticular ejection fraction (LVEF) of 35.9 ± 4.7% were prospectively and randomly enrolled in a single center interventional, open labeled clinical trial as two groups: group I of 15 patients designated as the study group to receive CABG surgery and intramyocardial implantation of BMMNC and group II of 15 patients as the control group to receive only the CABG procedure. All the patients in both groups received the average of 3.4 ± 0.7 implanted coronary grafts, and all of them received the left internal mammary artery (LIMA) to the left anterior descending (LAD) and autovenous to other coronaries. RESULTS: The group with BMMNC and CABG had the average of 17.5 ± 3.8 injections of BMMNC suspension with the average number of injected bone marrow mononuclear cells of 70.7 ± 32.4 x 10(6) in the total average volume of 5.7 ± 1.5 mL. In this volume the average count of CD34+ and CD133+ cells was 3.96 ± 2.77 x 10(6) and 2.65 ± 1.71 x 10(6), respectively. All the patients were followed up in 2.5 to 7.5 years (median, 5 years). At the end of the follow-up period, siginificantly more patients from the group that received BMMNC were in the functional class I compared to the CABG only group (14/15 vs 5/15; p = 0.002). After 6 months the results on 6-minute walk test (6-MWT) were significantly different between the groups (435 m in the BMMNC and CABG group and 315 m in the CABG only group; p = 0.001), and continued to be preserved and improved on the final follow-up (520 m in the BMMNC and CABG group vs 343 m in the CABG only group; p < 0.001). Cardiovascular mortality was also significantly reduced in the BMMNC and CABG group (p = 0.049). CONCLUSION: Implanatation of BMMNC concomitant to CABG is a safe and feasible procedure that demonstates not only the improved functional capacity but also a reduced cardiac mortality in a 5-year follow-up in patients with ischemic cardiomyopathy scheduled for CABG surgery.

Coronary thrombi neovascularization in patients with ST-elevation myocardial infarction - clinical and angiographic implications.

INTRODUCTION: Coronary artery thrombosis in ST-elevation myocardial infarction (STEMI) is a dynamic process often preceded by episodes of silent plaque rupture and subocclusive thrombosis. Thrombus organization is achieved by ingrowth of endothelial and smooth muscle cells. Clinical significance and impact of thrombus neovascularization on primary percutaneous coronary intervention (pPCI) outcome remain unclear. Therefore we investigated composition and neovascularization of thrombi aspirated during pPCI and their association with clinical and angiographic parameters of STEMI patients. METHODS: Aspirated thrombi retrieved from 84 STEMI patients were classified as fresh (<1 day), lytic (1-5 days) or organized (>5 days). Thrombus neovascularization was evaluated immunohistochemically using CD34, CD31 and VEGF antibodies. CD34 and CD31 immunopositive (CD34/CD31+) cells were organized as single, clusters and microvessels. VEGF positivity was graded as low or high, based on thrombus surface immunopositive area. RESULTS: CD34/CD31+ cells were present in 67% of all aspirated thrombi. Thrombus CD34/CD31 positivity was associated with previous history of angina pectoris (χ(2)=6.142, p=0.013) and lower myocardial blush grade (MBG<3, χ(2)=12.602, p<0.001). Organization of CD34/CD31+ cells showed inverse association with the extent of VEGF positivity (χ(2)=10.607, p=0.005). Fresh thrombi were associated with shorter ischemic time (U=237.5, p=0.002) and MBG 3 (χ(2)=6.379, p=0.012). CONCLUSIONS: Older thrombus age and neovascularization are associated with suboptimal myocardial perfusion in STEMI patients. Thrombus VEGF expression is inversely associated with degree of CD34+ cell organization. Therefore, neovascularization of aspirated thrombi may indicate the duration of thrombosis, coronary microcirculation status and outcome in STEMI patients.

Treatment of acute Jones fracture with Ilizarov external minifixator: case series of six elite athletes.

No consensus has been reached about the optimal treatment of Jones fractures, especially in elite athletes. Furthermore, only limited experience with external fixation of acute Jones fractures in these patients is available. The aim of the present retrospective study was to report the clinical evaluation of a series of 6 patients--elite athletes--with unilateral acute Jones fracture, who underwent external fixation of the fracture with an Ilizarov minifixator. Treatment success and the intervals to union and the return to full athlete activity were measured for each patient. The mean follow-up duration was 48 (range 24 to 72) months. The average period from surgery to clinical healing of the fracture was 4.1 (range 4.0 to 4.2) weeks, and the interval from surgery to radiographic consolidation of the fracture was 5.8 (range 5.4 to 6.4) weeks. The patients had returned to full athletic activity by 6.7 (range 6.4 to 6.9) weeks postoperatively. No major complications developed. No cases of treatment failure (nonunion, delayed union, or refracture) were observed during the follow-up period. Our results have shown that the Ilizarov external minifixator is a reliable surgical option for the treatment of acute Jones fractures in elite athletes, allowing an early return to full competitive athletic activity. Application of this apparatus is fast and relatively simple, with a percentage of radiographic consolidation and clinical healing comparable to that with screw fixation techniques.