Segment Of LAD Research Articles

Prognostic value of noninvasive coronary flow reserve during dobutamine provocation in patients with myocardial bridging in long-term follow-up

Abstract Background Recent studies showed that noninvasive coronary flow velocity reserve (CFR) measurement during inotropic stimulation with dobutamine (DOB) provides more reliable functional evaluation of myocardial bridging (MB). Additionally, a CFR cut-off value <2.1 during DOB was found to be the most reliable for the identification of MB associated with stress-induced myocardial ischemia. However, studies of clinical outcomes during long-term follow-up associated with the use of noninvasive CFR are lacking. The aim of the study was to evaluate major adverse cardiac events (MACE: unstable angina [UA] that required hospitalization, non-fatal myocardial infarction [MI], and all-cause mortality) associated with established CFR ischemic threshold during long-term follow-up. Methods This study included 79 patients (54 males, mean age 55±10 years) with angiographic evidence of isolated MB on the left anterior descending artery and systolic compression ≥50% diameter stenosis assessed by quantitative coronary angiography. CFR at peak DOB (30-40 μg/kg/min) was measured in the distal segment of LAD, and patients were divided into two groups according to previously validated CFR threshold of <2.1. Patients were monitored (ambulatory, hospital, and by telephone) for the occurrence of MACE over a median follow-up 8.2 years (interquartile range: 4.4 to 9.2 years) after enrollment. Results A total of 22 events were occurred in 20 patients: UA that required hospitalization in 20 patients (25%), nonfatal-MI in 1 patient (1.2%), and death in 1 patient (1.2%). The group of MB-patients with CFR <2.1 had 3.9 times higher rate of MACE during long-term follow-up in comparison to the group of MB-patients with CFR >2.1 (HR 3.90; 95% CI: 1.673-9.072; p=0.002). This was mainly driven by a 4-fold higher rate of UA that required hospitalization (HR 4.33; 95%CI: 1.773-10.589; p<0.001). Conclusion In MB-patients, CFR <2,1 during DOB provocation is associated with a significantly higher rate of UA that required hospitalization, whereas long-term prognosis with respect to death and nonfatal-MI was similar in both groups.

Excluding significant coronary artery disease in patients planned for TAVR using CT: Diagnostic accuracy of newest generation dual source photon counting scanner compared to coronary angiography

Abstract Introduction Patients with significant aortic stenosis routinely undergo CT for evaluation of the aortic root prior to interventional aortic valve replacement (TAVR). Assessment of CAD is usually performed by invasive coronary angiography. We assessed the diagnostic accuracy of the latest generation dual source photon counting scanner for exclusion of relevant CAD in a contemporary TAVR cohort. Methods Patients referred for cardiac CT prior to transcatheter aortic valve implantation were screened for inclusion this analysis. All cardiac CT exams were performed by dual source photon counting scanner (NAEOTOM alpha, Siemens healthineers, Germany). CT acquisitions were performed using retrospectively triggered spiral acquisition (30-70% of the cardiac cycle) without ultra-high resolution. For each patient, several reconstructions were rendered (thin slice reconstruction with 0.4 mm slice thickness: best diastolic phase, best systolic phase, 200-350 ms folllowing R-wave in 50 ms intervals as well as 0.6 mm slice thickness multiphase reconstruction 0-90% of the cardiac cycle in 10 % increments). Assessment of significant CAD was performed in CT and invasive angiography on a per-vessel analysis and a per-patient analysis using 2 thresholds: ≥ 50% stenosis and ≥ 70% stenosis. Assessment of stenoses in CT was performed using multiplanar reconstructions (MPR) and curved MPR and only in vessels > 1.5mm diameter. Assessment of stenosis in invasive angiography was performed using the projection with the most relevant lumen reduction. Image quality in CT was assessed on a likert scale from 1 to 4 (1=excellent, 2=minor artifacts, 3=major artifacts still assessable, 4=non-assessable). Results In this analysis 31 consecutive patients were included (mean age 79.5y, 64.5% males, 35.5% females). Mean heart rate was 66.5 bpm and 19% were in atrial fibrillation during CT acquisition. Mean image quality was 1.4. 13 Patients had no relevant CAD (stenosis ≥50%) in invasive angiography and in 18 patients at least 1 vessel was deemed to have ≥ 50% stenosis in invasive angiography. On a per vessel analysis, sensitivity, specificity and accuracy of cardiac CT to exclude stenoses using 50% and 70% thresholds were 98%, 93% and 94% vs. 97%, 93% and 94%, respectively. Negative likelihood ratio was 0.02 vs. 0.03 respectively. On a per-patient level, sensitivity and specificity were 100%. Out of 31 patients, only 2 vessels in 2 patients were deemed non-assessable. 3 patients with previous PCI as well as 3 patients with previous CABG were included in this analysis. Only 1 false negative vessel was reported in a very distal LAD segment. Conclusion Using newest generation dual source CT with photon counting, CT allowed highly reliable diagnostic workup regarding the presence of CAD in this TAVR cohort. The use of CT to assess CAD in TAVR patients seems clinically feasible especially in patients without previous percutaneous revascularisation.

Comparison of six Z-score formulas based on echocardiography for coronary artery lesions in Kawasaki disease

GoalKawasaki disease (KD) patients are at risk of developing the serious complication of coronary artery dilation (CAD). To diagnose CAD caused by KD, various Z-Score formulas are used worldwide. This paper aims to evaluate the differences and inclusiveness among the six most commonly used Z-Score formulas in diagnosing CAD in Suzhou, China. Additionally, the study seeks to compare the differences in CAD diagnosis among different high-risk factor groups. By doing so, this research provides a valuable reference for accurately diagnosing CAD in KD patients. MethodThis paper presents a retrospective analysis of 1509 patients diagnosed with KD at the Children's Hospital of Soochow University between January 2018 and December 2020. We collected the patients' clinical and echocardiographic data and used six Z-Score formulas (Kobayashi et al., de Zorzi et al., Kurotobi et al., McCrindle et al., Olivieri et al., and Dallaire et al.) to diagnose the degree of CAD in different segments. We then compared the diagnostic differences and inclusiveness of these formulas, especially the diagnostic differences in medium to giant CAA. To achieve this, we divided the patients into groups based on their age (≤12 months, 13–30 months, and > 30 months) and fever duration (≤5 days, 6–7 days, 8–9 days, and ≥ 10 days). Using the McNemar test and the Kappa test, we compared the differences and the consistencies of CDA diagnosis among the six Z-Score formulas. Moreover, we used the Friedman test and Chi-square segmentation formula to compare the differences in age and number of fever duration between groups and to compare each Z-Score formula pair within the group. ResultsExcept for the LMCA segment, where there were no statistically significant differences between de Zorzi formula and McCrindle formula, the Z-score formulas showed statistically significant differences in the degree of CAD diagnosis across all other segments. Inclusiveness assessment revealed that Kobayashi formula and Dallaire formula showed significantly higher rates of dilatation (6.58% and 5.32%), or of small aneurysms (6.52% and 4.52%) compared to other formulas (1.0%–1.73%). Medium aneurysms were also more likely to be identified with Kobayashi and Dallaire formulas (0.8% and 0.8%) compared to the remaining formulas (0.13–0.40%). There are significant differences in the diagnoses of medium to giant CAA made by these six formulas in LAD and RCA. The longer the duration of fever and the younger the age, the higher the diagnosis rates of CAD and CAA. There were no statistically significant differences between de Zorzi formula and McCrindle formula, de Zorzi formula and Oliveri formula, and Kurotobi formula and Dallaire formula within the four groups based on the duration of fever. Similarly, there were no statistically significant differences between Kobayashi formula and Dallaire formula, and between de Zorzi formula and Oliveri formula in the age groups of ≤12 months and 13–30 months. ConclusionThere are diagnostic differences among these six Z-score formulas, considering the aforementioned statistics. Kobayashi formula and Dallaire formula are more inclusive, and less likely to under-diagnose significant CAD. They perform evenly for dilatation only, for small aneurysms and the median size aneurysms, and that is for segments of LMCA, LAD and RCA. In addition, McCrindle formula joins the “inclusive” pack for LAD and RCA in the matter of CAD. The younger the age of the patients and the longer the duration of fever, the higher the diagnosis rates of CAD and CAA. Furthermore, the younger the age of the patients and the shorter the duration of fever, the greater the differences between the various formulas.

Doxorubicin alters G-protein coupled receptor-mediated vasocontraction in rat coronary arteries.

Doxorubicin (Doxo)-associated cardio-and vasotoxicity has been recognised as a serious complication of cancer chemotherapy. The purpose of this novel paper was to determine the effect of Doxo on G-protein coupled receptor (GPCR)-mediated vasocontraction located on vascular smooth muscle cells. Rat left anterior descending artery segments were incubated for 24h with 0.5 µM Doxo. The vasocontractile responses by activation of endothelin receptor type A (ETA) and type B (ETB), serotonin receptor 1B (5-HT1B) and thromboxane A2 prostanoid receptor (TP) were investigated by a sensitive myography using specific agonists, while the specificity of the GPCR agonists was verified by applying selective antagonists (i.e. ETA and ETB agonist = 10- 14-10- 7.5 M endothelin-1 (ET-1); ETA antagonist = 10 µM BQ123; ETB agonists = 10- 14-10- 7.5 M sarafotoxin 6c (S6c) and ET-1; ETB antagonist = 0.1 µM BQ788; 5-HT1B agonist = 10- 12-10- 5.5 M 5-carboxamidotryptamine (5-CT); 5-HT1B antagonist = 1 µM GR55562; TP agonist = 10- 12-10- 6.5 M U46619; TP antagonist = 1 µM Seratrodast). Our results show that 0.5 µM Doxo incubation of LAD segments leads to an increased VSMC vasocontraction through the ETB, 5-HT1B and TP GPCRs, with a 2.2-fold increase in ETB-mediated vasocontraction at 10- 10.5 M S6c, a 2.0-fold increase in 5-HT1B-mediated vasocontraction at 10- 5.5 M 5-CT, and a 1.3-fold increase in TP-mediated vasocontraction at 10- 6.5 M U46619. Further studies unravelling the involvement of intracellular GPCR signalling pathways will broaden our understanding of the Doxo-induced vasotoxicity, and thus pave the way to mitigate the adverse effects by potential implementation of adjunct therapy options.

Novel implementation of cardiac magnetic resonance first-pass perfusion imaging for semi-quantitatively evaluating microvascular dysfunction in paediatric patients with Duchenne muscular dystrophy.

The current study aimed to assess myocardial microcirculation dysfunction via cardiac magnetic resonance (CMR) first-pass perfusion imaging in children with Duchenne muscular dystrophy (DMD). In total, 67 children with DMD and 15 controls who underwent contrast-enhanced CMR first-pass perfusion imaging were enrolled in this study. CMR first-pass perfusion and late gadolinium enhancement (LGE) sequences were acquired. Further, the global, regional, and coronary artery distribution area perfusion indexes (PI), upslope (%BL), maximum signal intensity (MaxSI), time to maximum signal intensity (TTM), and baseline SI were analysed. The perfusion parameters of the LGE positive (+), LGE negative (-), and control groups were compared. Pearson correlation analysis was performed to assess the association between myocardial microcirculation and conventional cardiac function and LGE parameters. The LGE+ group had a significantly lower global and apical-ventricular MaxSI than the control group (all P < .05). The left anterior descending arterial (LAD), left circumflex coronary arterial (LCX), and right coronary arterial (RCA) segments of the LGE+ group had a lower upslope and MaxSI than those of the control group (all P < .05). The LAD segments of the LGE- group had a lower MaxSI than those of the control group (41.10 ± 11.08 vs 46.36 ± 13.04; P < .001). The LCX segments of the LGE- group had a lower PI and upslope than those of the control group (11.05 ± 2.84 vs 12.46 ± 2.82; P = .001; 59.31 ± 26.76 vs 68.57 ± 29.99; P = .002). Based on the correlation analysis, the upslope, MaxSI, and TTM were correlated with conventional cardiac function and LGE extent. Paediatric patients with DMD may present with microvascular dysfunction. This condition may appear before LGE and may be correlated with coronary artery blood supply and LGE extent. First-pass perfusion parameters may reveal the status of myocardial microcirculation and reflect the degree of myocardial injury at an earlier time in DMD patients. Perfusion parameters should be analysed not only via global or base, middle, and apical segments but also according to coronary artery distribution area, which may detect myocardial microvascular dysfunction at an earlier stage, in DMD patients with LGE-.

Normal physiologic coronary flow velocity gradient across the left anterior descending artery in healthy asymptomatic subjects

Aim: Coronary flow velocity (CFV) can be obtained with transthoracic echocardiography (TTE) in the left anterior descending coronary artery (LAD). The physiologic flow velocity gradient across the different segments of LAD has not been established. This study aims to assess the normal values of resting CFV in proximal, mid, and distal LAD. Methods: In a single center, prospective, observational study design, TTE was attempted on 110 consecutive, asymptomatic middle-aged subjects (age = 55 years, 46% males) with a low likelihood of coronary artery disease (&lt; 5%). Resting CFV in the LAD was assessed with high-end machines, dedicated coronary pre-set, and high-frequency transducers by pulsed-wave Doppler under color-Doppler guidance in the proximal, mid, and distal segments. Results: The technical success rate for CFV imaging was lowest for the proximal (101/110, 92%), intermediate for mid (106/110, 96%), and highest for the distal segment (108/110, 98%). All 3 segments were interpretable in 101 subjects. CFV was highest in proximal segments (38.6 cm/s ± 3.9 cm/s), intermediate in mid segments (34.3 cm/s ± 6.04 cm/s, P &lt; 0.01 vs. proximal), and lowest in distal segments (28.1 cm/s ± 1.7 cm/s, P &lt; 0.01 vs. proximal and vs. mid). Conclusions: A resting evaluation of CFV-LAD can be obtained by TTE in the large majority of consecutive subjects referred to the echocardiography laboratory. Feasibility is highest for distal and lowest for proximal-LAD segments. There is a clear physiologic gradient of CFV with decreasing values, of about 10% for each step, going from proximal to mid and distal segments of LAD. When resting CFV is considered, the site of the sampling is important to obtain comparable and physiologically meaningful data.

Assessment of the Severity of Left Anterior Descending Coronary Artery Stenoses by Enhanced Transthoracic Doppler Echocardiography: Validation of a Method Based on the Continuity Equation.

To verify whether the severity of coronary stenosis could be non-invasively assessed by enhanced transthoracic coronary echo Doppler in convergent color Doppler mode (E-Doppler TTE) over a wide range of values (from mild to severe). Color-guided pulsed wave Doppler sampling in the left anterior descending coronary artery (LAD) was performed in 103 diseased LAD segments (corresponding to 94 patients examined) as assessed by quantitative coronary angiography (QCA) or intracoronary ultrasound (IVUS). The E-Doppler TTE examinations consisted of measuring the velocity (vel) at the stenosis site and a reference adjacent segment. Then the continuity equation (C-Eq) was applied to calculate the percent cross-sectional area reduction (%CSA) at the stenosis site. The applied formula was: %CSA = 100 × (1 - [TVIref × 0.5]/TVIs). TVI = the time velocity integral at the stenosis [s] and the reference site [ref], respectively); 0.5 = the correcting factor for a parabolic profile was used only when the % accelerated stenotic flow was >122% (AsF = diastolic peak vel at first site - diastolic peak vel at second site/diastolic peak vel at second site × 100). E-Doppler TTE feasibility was 100%. Doppler and QCA/IVUS-derived %CSA stenosis showed very good agreement over a large range of values (from mild to severe), with no significant bias; the maximum difference between QCA/IVUS and transthoracic Doppler %CSA was mostly around 20% with a few patients exceeding this limit (limits of agreement = -27.53 to 23.5%). The scattering was slightly larger for the non-significant stenoses. The correlation was strong (r = 0.89, p < 0.001). E-Doppler TTE is a feasible and reliable method for assessing the severity of LAD stenosis by applying the C-Eq.

P318 A LETHAL SPASM

Abstract S.F.E.G., a 52–year–old woman of Filipino origin, with no previous cardiology except arterial hypertension under therapy, came to our attention for a witnessed episode of cardiac arrest at home. Rescued by the emergency medical team, who found ventricular fibrillation at presentation, and performed ACLS with ROSC obtained after 3 DC shocks. The first ECG was unremarkable (sinus rhythm, diffuse ST depression). Total body CT was negative. Admitted to the Coronary Unit, the echocardiogram was normal for cavity dimensions and kinetics, as well was coronary angiography except for “short intramyocardial course in the second segment of LAD with slight systolic "milking". In the following days, however, there was a significant rise in HsTnI (1,000 → 47,000 ng/L), with concomitant sudden ventricular bigeminy and negative anterior T waves, akinesia of the anterior apical segments of the LV at cardiac ultrasound (not present at admission), in a patient still intubated and therefore with a non–evaluable clinic. Coronary angiography was repeated, which highlighted this time significant vasospasm affecting the middle segment of the LAD, that regressed after intracoronary nitrates. She was extubated without neurological sequelae, and subjected to ICD implantation by secondary prevention. To treat the vasospastic angina she was discharged with calcium channel blockers at the maximum tolerated dosage, as per guidelines (diltiazem 120mg TID + nifedipine 60mg BID). One month later the patient returned to our attention due to worsening dyspnoea, abdominal pain and anasarca (ascites, bilateral pleural effusion, peripheral oedemas). Hospitalized in a medical setting and treated with diuretics for suspected heart failure, despite the echocardiogram showing preserved biventricular systolic function, normal diastolic function, no valve disease, no pericardial effusion. BNP was 359 pg/mL, subsequently decreasing to 148 pg/mL. After excluding every other possible causes even with total body CT, our hypothesis was that of calcium channel blocker collateral effect (vasodilatory edema). We tapered the dosage until only diltiazem 60mg TID was mainteined, obtaining a significant clinical improvement (weight loss by 10 kg), without further recurrence of coronary vasospasm. This clinical case demonstrates the potential lethality of coronary vasospasm, and a rare complication during therapy with high doses of calcium channel blockers, with very few cases described in the literature.

Coronary computed tomography angiography study on the relationship between the Ramus Intermedius and Atherosclerosis in the bifurcation of the left main coronary artery

ObjectiveThis study aimed to explore the relationship between the ramus intermedius (RI) and atherosclerosis in the bifurcation of the left coronary artery (LCA).MethodsScreening patients who underwent CCTA from January to September 2021, 100 patients with RI (RI group) and 100 patients without RI (no-RI group) were randomly enrolled, Evaluation of RI distribution characteristics and left main coronary artery(LM),Left anterior descending branch(LAD),left circumflex branch(LCX) proximal segment plaque distribution, measurement of LAD-LCX bifurcation angle(∠LAD-LCX),Comparison of the three distribution characteristics with the incidence of plaques in the left main trunk bifurcation area (LM, LAD, LCX) between groups and within the RI group.ResultsThe difference in the incidence of plaques in the proximal LCX and the LM between the RI group and the no-RI group were not statistically significant (P > 0.05). The incidence of plaques in the proximal LAD in the RI group was significantly higher than that in the non-RI group (77% versus 53%, P < 0.05). However, there was no statistically significant difference between the two groups after PSM. A univariate logistic regression analysis revealed that an RI was a risk factor for plaque formation in the proximal LAD (P < 0.001), and a multivariate logistic regression analysis revealed that an RI was not an independent risk factor for plaque formation in the proximal LAD (P > 0.05). When compared within the RI group, the difference in the incidence of plaques in the proximal segment of LAD, the proximal segment of LCX, and the LM among the different distribution groups of RI was not statistically significant, respectively (P > 0.05).ConclusionRI is not an independent risk factor for atherosclerosis in the left coronary artery bifurcation zone, but it may indirectly increase the risk of atherosclerosis in the proximal segment of the LAD.

Распространенность, анатомо-топографические особенности и клиническое значение миокардиальных «мостиков»: ретроспективное исследование

Aim. To analyze the prevalence and anatomic-topographic features of myocardial bridges (MBs) and evaluate their role in the development of cardiovascular complications. Design. А retrospective study. Materials and methods. The study was conducted in two stages. In the first stage, to assess the prevalence and anatomic-topographic features of MBs, was retrospectively analyzed a registry of 883 coronary computed tomographic angiography (CCTA) results performed at the S.M. Kirov Military Medical Academy from 2011 to 2021. From the remaining 811 results after the initial review, 117 CCTA with MBs were selected and subjected to further detailed study. In 6 cases the CCTA was supplemented with stress-CT myocardial perfusion. In the second stage, a retrospective analysis of medical histories of 20 patients with MBs who were treated at the S.M. Kirov Military Medical Academy from 2017 to 2021 was performed for assessment the clinical significance of MBs and their role in the development of cardiovascular complications. Results. According to CCTA MBs were visualized in 14.4% of cases, in the left anterior descending artery (LAD) they were diagnosed in 84.6% of them with predominant localization in the middle segment — 94.9%. The mean length of the MBs in the LAD was 23 [17; 31] mm, depth — 1 [1; 2] mm. Atherosclerotic lesion according to classification of Coronary Artery Disease Reporting and Data System (CAD-RADS) of the LAD was detected in 58.6% of cases, of which in the proximal segment — 84.5%. According to stress-CT myocardial perfusion in asymptomatic patients, hypoperfusion was detected in 3 (50%) cases in the segments of the left ventricle, the blood supply of which comes from the LAD and its branches. Among 20 patients with dyslipidemia was detected in 80% of patients with MBs, stable angina was diagnosed in 5 (25%) cases, unstable angina and myocardial infarction — 3 (15%) patients in each cases. The assessment of the lipid spectrum revealed the elevations of total cholesterol to 5.47 ± 1.25 mmol/l and low-density lipoprotein to 3.52 ± 1.04 mmol/l, other fractions remained within normal values. In addition, various heart arrhythmias and conduction disorders were detected by 24-hour electrocardiography monitoring in patients with MBs, including supraventricular and ventricular extrasystoles, supraventricular and ventricular tachycardia, A-V blockade, atrial fibrillation and flutter and pauses greater than 2.5 seconds. Conclusion. The study confirmed the predominant character of MBs localization in the LAD and its middle segment. In addition, frequent atherosclerotic lesion of proximal segments of LAD by CAD-RADS classification was detected. The presence of association of MBs with symptoms of myocardial ischemia, dyslipidemia, as well as various arrhythmias requires searching of new approaches to early visualization of MBs, especially in the group of asymptomatic patients, in order to diagnose the pathology on time and prevent cardiovascular complications associated with it. Keywords: myocardial bridge, developmental abnormality, coronary computed tomographic angiography, dyslipidemia, myocardial ischemia, heart arrhythmias and conduction disorders.

Abstract EP65: Left Coronary Artery Cross-sectional Area And Traditional Cardiovascular Risk Factors Among Asymptomatic South Asians: Results From The MASALA Study

Background: South Asians have a higher atherosclerotic cardiovascular disease (ASCVC) burden than other race/ethnic groups that is not fully explained by traditional risk factors. Smaller coronary artery luminal diameter has been proposed as a potential reason for this higher risk among South Asians. A few studies have measured coronary artery diameter in South Asians demonstrating smaller coronary luminal diameter explained by smaller body size. However, these studies were done symptomatic individuals with high burden of coronary plaque, and stenosis and vascular tone is known to impact lumen diameter. No studies have measured coronary artery external diameters in asymptomatic South Asians. Methods: We analyzed data from 513 participants, between ages of 42 and 68 years, enrolled in the Mediators of Atherosclerosis in South Asians Living in America (MASALA) Study (2016-2018). We analyzed coronary cross-sectional area (CSA) with thin slice non-contrast cardiac CT scans. This is equivalent to the outermost (adventitial) boundary measured with intravascular ultrasound of the coronary arteries. We computed mean CSA in the proximal and mid LAD segments perpendicular to the centerline of the vessel. We examined bivariate associations of traditional cardiovascular risk factors and coronary artery calcium (CAC) with LAD CSA. We then created multivariable models adjusted for age and sex to determine independent correlations with LAD CSA. Results: We used data from 285 men and 228 women with mean age 56±7 years. The overall mean LAD CSA was 22.8±6.8 mm 2 for men and 17.6±6.2 mm 2 for women. In bivariate analysis, higher LAD CSA was associated with male sex, and higher age, BMI, waist circumference, systolic and diastolic blood pressures, fasting glucose, total and LDL-cholesterol, CAC scores, statin medication use, and lower HDL-cholesterol. In multivariable models, only male sex (β 0.044, p&lt;0.001), hypertension (β 0.024, p&lt;0.001), and BMI (β 0.003 per kg/m 2 , p &lt;0.001) were significantly associated with LAD CSA. High CAC was marginally associated with LAD CSA (CAC&gt;100: B 0.015 p = 0.065) while age, diabetes, and cholesterol levels were not independently associated with LAD CSA. Conclusion: These preliminary results suggest that LAD CSA is highly correlated with sex, body size, and hypertension, but not other metabolic risk factors that are more aberrant among South Asians. Long-term follow-up will determine whether LAD CSA is an important contributor to cardiovascular disease events among South Asians.

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.

233 Prognostic implications of the automated detection of lipid core burden index at optical coherence tomography: post hoc analysis of the CLIMA study

Abstract Aims Plaque vulnerability features are associated with major coronary events and poor outcomes. However, routinary and reproducible manual assessment of plaque vulnerability features at optical coherence tomography (OCT) is still challenging. We recently developed and validated an OCT-derived automated approach that can identify the intra-plaque lipid core burden index (LCBI). Our aim was to investigate the association between the automated detection of OCT-derived LCBI and clinical events. Methods and results We conducted a post hoc analysis of the CLIMA study, a large prospective observational, multicentre registry recruiting all consecutive patients undergoing assessment of the proximal left anterior descending artery (LAD) segment by OCT in the context of clinically indicated coronary angiography. The automated detection of maximum LCBI was carried out in 4 mm of intervention-naïve proximal LAD segment (maxLCBI4mm) by using the validated software. The mean and median value of LCBI in all study population (n = 1003) was 407.6 and 411.1, respectively. Patients with higher LCBI (≥400) were more frequently male (P = 0.016) and affected by insulin-dependent diabetes mellitus (0.046). Furthermore, they showed more frequently at OCT analysis the vulnerable plaque characteristics investigated in the CLIMA study (Table 1). At Cox regression analysis, a maxLCBI4mm ≥400 predicted at 1 year both a hard endpoint of cardiac death and target-vessel myocardial infarction [hazard ratio (HR): 2.56, 95% confidence interval (CI): 1.2–5.3, P 0.011], as well as a composite endpoint of cardiac death, any myocardial infarction and target vessel revascularization (HR: 1.87, 95% CI: 1.1–3.1, P = 0.011). Conclusions In our study, the automated detection of LCBI at OCT was feasible and related to poorer clinical outcome at 1-year follow-up.

Clinical Outcomes After Current-Generation Drug-Eluting Stent Implantation for Ostial Left Circumflex Lesions

BackgroundThere are no available data about clinical outcomes of simple stenting for ostial left circumflex (LCX) lesions using current generation drug-eluting stents (cDES). ObjectiveWe assessed clinical outcomes after simple stenting using cDES for ostial LCX lesions. MethodsWe identified 81 consecutive patients who underwent PCI using cDES for ostial LCX lesions at New Tokyo Hospital, Matsudo, Japan between January 2010 and December 2016. An ostial LCX lesion was defined as a lesion with more than 75% stenosis by visual assessment and within 3 mm of the left main (LM) stem. The primary endpoint was target lesion failure (TLF). TLF was defined as a composite of cardiac death, target lesion revascularization (TLR) and myocardial infarction (MI). Additionally, we also assessed the revascularization for LM to left anterior descending artery (LAD) after ostial LCX stenting. ResultsThe TLF rate at 3 years after PCI was 24.5%. Furthermore, the rate of TLR and revascularization for LM-LAD after ostial LCX stenting were significantly higher in patients who were previously undergone stent implantation in ostial segment of LAD. ConclusionClinical outcomes after cDES implantation for ostial LCX lesion could be acceptable. However, it could have better to be avoided in patients who previously received stent implantation in ostial segment of LAD.

Extensive anterior myocardial infarction of an older non diabetic patient has better prognosis compared to a younger patient: a case report

ST elevation myocardial infarction (STEMI) incidence rates has been decreased inversely to non-STEMI (121 to 77, 126 to 132 per 100.000 case respectively). Diabetes as a risk factors of STEMI is found in 20% patients. The increment of fibrinogen level in diabetic patient may induce compact clots resistance to fibrinolysis that lead to hypercoagulable state problem. Percutaneous coronary intervention (PCI), a non-surgical invasive procedure, can be done to relieve the obstruction. We reported two case reports, patients with anterior extensive STEMI who had underwent primary PCI. Both patients were found a total occlusion at proximal segment of LAD. First case was presented type 2 diabetes mellitus as comorbid while the second case was without diabetes. High burden thrombus was found on the diabetic patient which had poor prognosis, but on the non diabetic patient was found only less thrombus which was more stable condition. There is a strong correlation between type 2 diabetes mellitus and cardiovascular disease (CVD). Glucose control is important for prevention of CVD. Dietary changes that are characterized by increased use of natural sources diets such as whole grains, vegetables, and fruit-based foods and increased physical activity is remarkably strong factors for diabetes prevention.

Coronary Artery Dimensions in Endurance Athletes by Computed Tomography Angiography: A Quantitative Analysis.

(1) Background: The athlete’s heart may develop permanent vessel enlargement. The purpose of our study was to define normal values for coronary artery dimensions of endurance athletes by coronary computed tomography angiography (CTA). (2) Methods: Ninety-eight individuals (56.2 ± 11 years) were included into this retrospective matched case-controlled-study. Endurance athletes had regular training volumes of ≥1 h per unit, ≥3–7 times per week (either cycling, running or mountain-endurance). Athletes were matched for age and gender with sedentary controls using propensity score. Quantitative CTA analysis included coronary vessel dimensions (two diameters and area) of the LM, LAD, CX and RCA for all AHA-16-segments. (3) Results: Proximal LAD area and diameter (p = 0.019); proximal/mid CX (diameter and area; p = 0.026 and p = 0.018/p = 0.008 and p = 0.009); mid RCA diameter and area; and proximal RCA diameter were significantly larger in endurance athletes (p < 0.05). The left main area (p = 0.708) and diameter (p = 0.809) as well as the mid LAD and distal segments were not different. We present the histograms and data for normal values ±1 and ± 2 SD. (4) Conclusions: Endurance athletes have larger proximal LAD, proximal/mid CX and RCA vessel dimensions, while LM and distal segments are similar. Hence, dilated coronary arteries in endurance athletes (“Athlete’s arteries”) have to be distinguished from diffuse ectatic segments developing during Kawasaki disease or multisystemic inflammation syndrome after COVID-19.

Exercise capacity benefit in relation to endogenous testosterone, coronary and central vascular physiology, and the Mediterranean regime in hypertensive males with erectile dysfunction

Abstract Background The Mediterranean diet (Med-diet) benefits cardiovascular health, and erectile dysfunction (ED) often coexists in the hypertensive aging male population were endogenous testosterone (TT) typically declines. Coronary flow reserve (CFR) displays the ability of the coronary circulation to increase flow. Wave reflection amplification as expressed by augmentation index (AIx) exhibits a vital parameter of central vascular stiffness. Purpose To investigate the possible benefits of the Med-diet in exercise capacity, central physiology, CFR and erectile ability in relation to endogenous TT in the middle aged male hypertensive population with ED. Methods 250 hypertensive males (mean age 56 yo) with ED enrolled the study. All underwent a treadmill stress test (Bruce protocol). Exercise capacity was validated as metabolic equivalents (METs). We measured separately the CFR of the left anterior descending artery by an adenosine protocol (max dose 140μg/kg/min over 6 minutes). PW Doppler measurements were achieved at the middle/distal LAD segment under the guidance of color Doppler flow mapping. CFR was validated as ratio between peak diastolic flow velocity following drug infusion and rest. Ratios ≥2 are considered as non-ischemic response, higher values indicate microvascular coronary integrity. TT was measured on blood samples taken before 09:00 am. ED severity and adherence to the Med-diet were assessed by the SHIM-5 (range: 0–25) and the Med-diet (range: 0–55) scores. Higher values indicate a better erectile ability and Med-diet compliance respectively. Finally, central pulse pressure (cPP) and AIx were noninvasively estimated as parameters of central hemodynamic load and wave reflection amplification (Sphygmocor device). Results In bivariate analysis METs were positively associated to the Med-diet, CFR, TT and the SHIM-5 score (all p&amp;lt;0,005) and negatively to the AIx and cPP (both p&amp;lt;0,025). There was also positive association of the Med-diet to the CFR, TT and the SHIM-5 score (p&amp;lt;0,02) and negative to the AIx and cPP (p&amp;lt;0,025). By linear regression analysis association of METs to TT, CFR and Med-diet remained significant after adjustment for age, BMI, diabetes mellitus, use of statins and smoking status (p&amp;lt;0,005). We further subdivide our population according to the TT threshold of hypogonadism (≤3 ng/ml). Hypogonadism patients exhibit a lower exercise capacity comparing to the normal TT group (picture). Conclusion The Med-diet regime benefits exercise tolerance and erectile performance in hypertensive males with ED by enhancing endogenous testosterone and so coronary and central vascular physiology. We strongly recommend this culinary preference promoting thus vascular health and the sense of well being. Funding Acknowledgement Type of funding sources: None.

Cut-off value of coronary flow velocity reserve obtained by transthoracic Doppler echocardiography during intravenous infusion of dobutamine for diagnosis of functional significant myocardial bridging

Abstract Background Recent studies showed that coronary flow velocity reserve (CFVR) measurement by transthoracic Doppler echocardiography (TTDE) during inotropic stimulation with dobutamine (DOB), in comparison to vasodilation with adenosine, provides more reliable functional evaluation of myocardial bridging (MB). However, the adequate cut-off value of CFVR during DOB for diagnosing functional significant MB has not been fully established. Purpose The purpose of the study was to evaluate the adequate cut-off value of TTDE- CFVR during DOB for diagnosis of functional significant MB. Methods This prospective study included 79 patients (54 males, mean age 55±10 years) with angiographic evidence of isolated MB on the left anterior descending artery (LAD) and systolic compression ≥50% diameter stenosis. Exercise stress-echocardiography test (ExSE) and TTDE-CFVR in the distal segment of LAD during DOB infusion (DOB: 10–40μg/kg/min) were performed in all patients. Percent diameter stenosis (DS) of MB at end-systole and end-diastole were analyzed using quantitative coronary angiography. Results Exercise-SE was positive for myocardial ischemia in 22/79 (28%). CFVR during peak DOB was significantly lower in SE-positive group in comparison to SE-negative group (1.94±0.16 vs. 2.78±0.53, p&amp;lt;0.001). ROC analysis identifies the optimal CFVR during peak DOB cut-off value &amp;lt;2.1 (AUC 0.985, 95% CI: 0.965–1.000, p&amp;lt;0.001), with a sensitivity of 96% and specificity of 95%, positive predictive value of 88%, and negative predictive value of 98%, for identifying functionally significant MB associated with stress-induced myocardial ischemia. The categorical agreement between TTDE-CFVR at peak DOB and ExSE was high (kappa value = 0.877, p&amp;lt;0.001). Multivariate logistic regression analysis showed that percent DS at end-diastole was the only independent predictor of ischemic CFVR value &amp;lt;2.1 (OR: 1.136, 95% CI: 1.045–1.235, p=0.003). Conclusion A cut-off value &amp;lt;2.1 of CFVR during DOB infusion obtained by TTDE may adequate discriminate functional significant MB that induce myocardial ischemia which is caused by an incomplete diastolic MB-decompression. Funding Acknowledgement Type of funding sources: None.

Incremental value of early systolic lengthening and postsystolic shortening in detecting left anterior descending artery stenosis using nonstress speckle-tracking echocardiography

The diagnosis of coronary artery disease (CAD) with nonstress echocardiography remains challenging. Although the assessment of either early systolic lengthening (ESL) or postsystolic shortening (PSS) allows the sensitive detection of CAD, it is unclear whether the integrated analysis of ESL and PSS in addition to the peak systolic strain can improve the diagnostic accuracy. We investigated the incremental value of ESL and PSS in detecting left anterior descending artery (LAD) stenosis using nonstress speckle-tracking echocardiography. Fifty-nine patients with significant LAD stenosis but without visual wall motion abnormalities on echocardiography at rest (30 single-vessel stenosis, 29 multivessel stenosis) and 43 patients without significant stenosis of any vessel were enrolled. The peak systolic strain, the time to ESL (TESL), and the time to PSS (TPSS) were analyzed in all LAD segments, and the incremental values of the TESL and TPSS in detecting LAD stenosis and the diagnostic accuracy were evaluated. In the apical anterior segment, the peak systolic strain was significantly lower and TESL and TPSS were significantly longer in the single-vessel group than in the no stenosis group. In the single-vessel group, the addition of TESL and TPSS to the peak systolic strain significantly increased the model power in detecting stenosis, and the integrated analysis improved diagnostic accuracy compared with the peak systolic strain alone. In contrast, this incremental value was not demonstrated in the multivessel group. The integrated analysis of the peak systolic strain, ESL, and PSS may allow better screening of single-vessel LAD stenosis using nonstress speckle-tracking echocardiography.

Influence of coronary stenosis location on diagnostic performance of machine learning-based fractional flow reserve from CT angiography

BackgroundCompared with invasive fractional flow reserve (FFR), coronary CT angiography (cCTA) is limited in detecting hemodynamically relevant lesions. cCTA-based FFR (CT-FFR) is an approach to overcome this insufficiency by use of computational fluid dynamics. Applying recent innovations in computer science, a machine learning (ML) method for CT-FFR derivation was introduced and showed improved diagnostic performance compared to cCTA alone. We sought to investigate the influence of stenosis location in the coronary artery system on the performance of ML-CT-FFR in a large, multicenter cohort. MethodsThree hundred and thirty patients (75.2% male, median age 63 years) with 502 coronary artery stenoses were included in this substudy of the MACHINE (Machine Learning Based CT Angiography Derived FFR: A Multi-Center Registry) registry. Correlation of ML-CT-FFR with the invasive reference standard FFR was assessed and pooled diagnostic performance of ML-CT-FFR and cCTA was determined separately for the following stenosis locations: RCA, LAD, LCX, proximal, middle, and distal vessel segments. ResultsML-CT-FFR correlated well with invasive FFR across the different stenosis locations. Per-lesion analysis revealed improved diagnostic accuracy of ML-CT-FFR compared with conventional cCTA for stenoses in the RCA (71.8% [95% confidence interval, 63.0%–79.5%] vs. 54.8% [45.7%–63.8%]), LAD (79.3 [73.9–84.0] vs. 59.6 [53.5–65.6]), LCX (84.1 [76.0–90.3] vs. 63.7 [54.1–72.6]), proximal (81.5 [74.6–87.1] vs. 63.8 [55.9–71.2]), middle (81.2 [75.7–85.9] vs. 59.4 [53.0–65.6]) and distal stenosis location (67.4 [57.0–76.6] vs. 51.6 [41.1–62.0]). ConclusionIn a multicenter cohort with high disease prevalence, ML-CT-FFR offered improved diagnostic performance over cCTA for detecting hemodynamically relevant stenoses regardless of their location.