Amal Sharif-Rasslan

Detection of severe left anterior descending coronary artery stenosis by transthoracic evaluation of resting coronary flow velocity dynamics

In the presence of severe stenosis, coronary artery flow may be reduced at rest. Recent advances in echocardiography have made non-invasive sampling of velocities in the left anterior descending coronary artery (LAD) possible. The aim of our study was to evaluate feasibility and capability of transthoracic Doppler to detect severe stenosis of the LAD. The study population consisted of 42 subjects with suspected coronary artery disease scheduled for coronary angiography. All had complete transthoracic echocardiography and Doppler sampling of LAD velocities. Quantitative coronary angiography was performed within 24 hours of the echocardiogram. Correlations between LAD velocity profile, measurements and calculations, and the angiographic results were performed. Six subjects had LAD occlusion, 10 had severe (>80% diameter) LAD stenosis, and 26 had normal or non-occlusive LAD disease. In all six subjects with LAD occlusion, distal LAD velocities were not detectable, while in the other 36 subjects, LAD velocities were recorded indicating the vessels were patent. In the 10 subjects with severe LAD stenosis, the diastolic/systolic velocity ratio was <1.5, while in those with non-significant LAD disease, the diastolic/systolic velocity ratio was >1.5 (P<0.005). Diastolic LAD flow was 21.8±13 mL/min in the presence of severe stenosis as compared to 48.5±20 mL/min in subjects without severe stenosis (P<0.0013). LAD velocities had high sensitivity and specificity for the prediction of severe angiographic stenosis. Thus transthoracic Doppler measurement of LAD velocities is feasible and can predict the presence of severe LAD stenosis or occlusion.

Left anterior descending coronary artery flow after primary angioplasty in acute anterior ST-elevation myocardial infarction: How much flow is needed for left ventricular functional recovery?

The treatment of choice in acute ST-elevation myocardial infarction (STEMI) is primary percutaneous coronary intervention (PPCI). Although, thrombolysis in myocardial infarction (TIMI) and myocardial blush grade (MBG) measures provide semi-quantitative flow evaluation after PPCI, serial and quantitative volumetric flow evaluation is still lacking. Aim: Serial assessment of left anterior descending (LAD) coronary artery flow in patients with anterior myocardial infarction (MI), immediately after PPCI, 48 h later and pre-discharge and compare findings in patients with optimal and suboptimal PPCI result and their relation to left ventricular ejection fraction (LVEF). Methods: Velocities in the LAD were recorded within 6 h after PPCI and one week later in 36 patients presenting with acute anterior STEMI. Sixteen patients had TIMI and MBG less than 3 after PPCI were considered to have suboptimal result. Sampling of LAD coronary artery velocity was obtained from trans-thoracic Doppler. Flow in the LAD coronary artery was estimated using heart rates, Doppler time velocity integrals and LAD color Doppler diameters. Results: Diastolic LAD coronary artery flow immediately after PPCI in subjects with suboptimal PPCI, 29±21 ml/min was lower than in those with optimal result, 39.8±21 ml/min, p<0.05. Diastolic flow in the LAD coronary artery increased to 50.3±28.5 ml/min two days after PPCI in patients with suboptimal PPCI, p=0.04, and to 49.6±13.8 ml/min in those optimal result, p=0.04. LVEF increased by 9% in patients with optimal PPCI, p=0.004, and did not change in the other group. Conclusions: (a) After PPCI, flow in the LAD coronary artery was dynamic; (b) in the presence of suboptimal PPCI, early LAD coronary artery flow was reduced; (c) pre-discharge, LAD coronary artery flow increased; and (d) LVEF increased only in optimal PPCI group associated with higher early LAD coronary artery flow.

Doppler echocardiographic myocardial stunning index predicts recovery of left ventricular systolic function after primary percutaneous coronary intervention.

Myocardial stunning is responsible for partially reversible left ventricular (LV) systolic dysfunction after successful primary percutaneous coronary intervention (PPCI) in patients with acute ST‐elevation myocardial infarction (STEMI).

Platelet counts on admission affect coronary flow, myocardial perfusion and left ventricular systolic function after primary percutaneous coronary intervention.

Background: Patients with acute ST-elevation myocardial infarction (STEMI) and increased platelet count treated by fibrinolysis have worse outcomes. Aim: The aim of this study was to test the hypothesis that platelet blood count at admission in patients with acute STEMI treated by primary percutaneous coronary intervention affects coronary flow, myocardial perfusion and recovery of left ventricular systolic function. Methods: A total of 174 patients presenting with acute anterior STEMI and treated with primary percutaneous coronary intervention were included and divided into subgroups of admission platelet blood count of <200 K, 200–300 K, 300–400 K and >400 K. Evaluation of coronary artery flow and myocardial blush grade was performed according to the TIMI criteria. Electrocardiographic ST elevation resolution post-primary percutaneous coronary intervention was evaluated. Doppler echocardiographic evaluation of left anterior descending coronary artery velocities early and late after primary percutaneous coronary intervention and assessment of left ventricular ejection fraction and wall motion score index (WMSI) of left ventricular and left anterior descending coronary artery territory were performed. Results: Post-primary percutaneous coronary intervention TIMI, myocardial blush grade and ST elevation resolution were similar in all groups. Patients with platelet counts <200 K had higher peak diastolic left anterior descending coronary artery velocity both early and late after primary percutaneous coronary intervention, and higher prevalence of left anterior descending coronary artery velocity deceleration time exceeding 600 ms, (45.5% vs. 40%, P<0.05). Patients with platelet counts >400 K presented with worse left ventricular ejection fraction, left ventricular WMSI and left anterior descending coronary artery WMSI, and before discharge this subgroup had worse left ventricular WMSI and left anterior descending coronary artery WMSI, P<0.01. Conclusions: Patients with anterior STEMI treated by primary percutaneous coronary intervention with lower admission platelet count had higher left anterior descending coronary artery diastolic velocities, better myocardial perfusion with more patients having left anterior descending coronary artery–descending coronary artery velocity deceleration time >600 ms. Patients with higher platelet counts had lower left ventricular systolic function both at admission and before discharge.

Sequential Evaluation of Coronary Flow Patterns after Primary Angioplasty in Acute Anterior ST-Elevation Myocardial Infarction Predicts Recovery of Left Ventricular Systolic Function

Function of the microcirculation after primary percutaneous coronary intervention (PCI) is dynamic and contributes to unpredictability of recovery of left ventricular (LV) systolic function.

Bivalirudin and Heparin Effects on Coronary Flow, Microcirculation and Recovery of Left Ventricular Systolic Function after Primary Coronary Angioplasty

In ST elevation myocardial infarction (STEMI) treated by primary per-coetaneous coronary intervention (PPCI), bivalirudin caused less bleeding and was as effective as combined heparin and IIb IIIa antagonist. Aim : Compare the effects of bivalirudin and heparin on coronary flow, microcirculation and recovery of left ventricular systolic function in patients with STEMI undergoing PPCI. Methods: Forty five patients with anterior STEMI undergoing PPCI, 30 treated with heparin and 15 with bivalirudin were compared. All patients had complete trans-thoracic Doppler echocardiographic studies and sampling of blood velocities in the left anterior descending coronary artery (LAD) early after PPCI and 5 days later. Results : TIMI and myocardial blush grades were similar in both groups before after PPCI. Peak LAD diastolic velocities early after PPCI were higher in the bivalirudin group 42.2±14.4 compared to the heparin group 34.06±8.27 cm/sec, p<0.03. Peak velocities in the LAD did not change significantly on follow up in both groups. Early diastolic velocity integrals in the LAD in patients treated with bivalirudin, 12.3±4.2 were higher than in those treated with heparin, 8.91±3.21cm, p<0.02, and this difference between the groups was maintained on late evaluation. Left ventricular systolic function parameters were similar in both treatment groups early and late after PPCI, however only heparin was associated with increase in these parameters on discharge from the hospital. Conclusions : Bivalirudin treatment in patients with anterior STEMI treated by PPCI was associated with higher LAD velocities and integrals compared to heparin, however only heparin increased LV systolic function after PPCI.

INTRA-AORTIC BALLOON COUNTER PULSATION AFTER PRIMARY PERCUTANEOUS CORONARY INTERVENTION AND SUBOPTIMAL CORONARY FLOW: HIGHER FLOW PREDICT HIGHER LEFT VENTRICULAR SYSTOLIC FUNCTION

Intra-aortic balloon (IABP) when applied in all patients with acute anterior ST elevation myocardial infraction (STEMI) treated by primary percutaneous coronary intervention (PPCI) and in patients with shock was not beneficial. Aim: Evaluation of the effects of IABP on coronary flow, myocardial

Differences in coronary artery blood velocities in the setting of normal coronary angiography and normal stress echocardiography

Background Normal left anterior descending (LAD) coronary artery as determined by coronary angiography is considered not only to reflect normal angiography but also to correlate with normal anatomy and function. However, subjects who undergo coronary angiography may differ from those who do not need to have invasive evaluation even if their functional noninvasive studies like dobutamine stress echocardiography (DSE) were normal. Aim LAD velocities in subjects with normal angiography and those with normal DSE are equal. Methods A total of 244 subjects were evaluated, 78 had normal LAD by angiography and 166 had normal LAD by DSE. All had Doppler sampling of LAD velocities by transthoracic echocardiography. Results Velocity was higher in the angiographic subgroup in diastole 41 ± 23 vs 33 ± 14 cm/s, p = 0.0078; systole 18 ± 14 vs 13 ± 7 cm/s, p = 0.012; diastolic integral 12.6 ± 5 vs 9.8 ± 3.8 cm, p = 3.15 × 10-5; systolic velocity integral 4 ± 2.9 vs 2.8 ± 1.9, p = 0.0014. While heart rate was similar in both groups, the product of diastolic velocity integral and heart rate of the LAD in the angiographic group was higher: 902 ± 450 vs 656 ± 394, p = 0.00599. Diastolic velocity deceleration time was similar in both groups. Coronary flow reserve defined as diastolic velocity ratio before and immediately after DSE correlated negatively with baseline velocity, r = -0.4. Conclusions Mode of defining normality of coronary artery affects velocity behavior of the vessel, reflecting functional differences possibly related to microvasculature and vasodilatation.

Effects of Eptifibatide on the Microcirculation After Primary Angioplasty in Acute ST-Elevation Myocardial Infarction: A Trans-Thoracic Coronary Artery Doppler Study

Cardiovascular atherosclerosis is the most common disease in the industrial countries. In the United States of America more than 1 million patients every year are admitted to the coronary care unit with suspected acute myocardial infarction (Yusuf et al, 2004; American Heart Association, 2007). The incidence of acute myocardial infarction in USA is 865000, 565000 of them new infarctions annually. In Europe, the situation is similar to the USA, however in northern countries the incidence is higher than in southern countries (Lopez et al, 2006). In the emerging market economies in Eastern Europe, higher cardiovascular mortality is found. The burden of cardiovascular and coronary heart disease in developing countries is approaching that in developed countries. Thus the problem is a worldwide problem and international joint efforts are needed in order to treat this still prevalent disease.