Enrica Mariano

Assessment of Flow Velocity Reserve by Transthoracic Doppler Echocardiography and Venous Adenosine Infusion Before and After Left Anterior Descending Coronary Artery Stenting

OBJECTIVES We sought to evaluate whether coronary flow velocity reserve (CFR) (the ratio between hyperemic and baseline peak flow velocity), as measured by transthoracic Doppler echocardiography during adenosine infusion, allows detection of flow changes in the left anterior descending coronary artery (LAD) before and after stenting. BACKGROUND The immediate post-stenting evaluation of CFR by intracoronary Doppler has shown mixed results, due to reactive hyperemia and microvascular stunning. Noninvasive coronary Doppler echocardiography may be a more reliable measure than intracoronary Doppler. METHODS Transthoracic Doppler echocardiography during 90-s venous adenosine infusion (140 microg/kg body weight per min) was used to measure CFR of the LAD in 45 patients before and 3.7 +/- 2 days after successful stenting, as well as in 25 subjects with an angiographically normal LAD (control group). RESULTS Adequate Doppler spectra were obtained in 96% of the patients. Pre-stent CFR was significantly lower in patients than in control subjects (diastolic CFR: 1.45 +/- 0.5 vs. 2.72 +/- 0.71, p < 0.01; systolic CFR: 1.61 +/- 1.02 vs. 2.41 +/- 0.68, p < 0.01) and increased toward the normal range after stenting (diastolic CFR: 2.58 +/- 0.7 vs. 2.72 +/- 0.75, p = NS; systolic CFR: 2.43 +/- 1.01 vs. 2.41 +/- 0.52, p = NS). Diastolic CFR was often damped, suggesting coronary steal in patients with > or =90% versus <90% LAD stenosis (0.86 +/- 0.23 vs. 1.69 +/- 0.43, p < 0.01). Coronary stenting normalized diastolic CFR in these two groups (2.45 +/- 0.77 and 2.64 +/- 0.69, respectively, p = NS), even though impaired diastolic CFR persisted in three of four patients with > or =90% stenosis. Stenosis of the LAD was better discriminated by diastolic (F = 49.30) than systolic (F = 12.20) CFR (both p < 0.01). CONCLUSIONS Coronary flow reserve, as measured by transthoracic Doppler echocardiography, is impaired in LAD disease; it may identify patients with > or =90% stenosis; and it normalizes early after stenting, even in patients with > or =90% stenosis.

Measurement of Coronary Flow Reserve in the Anterior and Posterior Descending Coronary Arteries by Transthoracic Doppler Ultrasound

We describe for the first time transthoracic Doppler ultrasound assessment of coronary flow reserve (CFR) in both the posterior descending (PDA) and left anterior descending (LAD) coronary arteries. CFR (hyperemic/resting diastolic flow velocity ratio) was measured by 90-second intravenous adenosine infusion (140 microg/kg/min). Baseline PDA flow was detected in 62 of 81 subjects (76%), and the CFR was measurable in 44 of them (54%) because of adenosine-induced hyperventilation. According to angiography, these 44 subjects were divided into 3 groups: group 1 (0% to 29% stenosis), group 2 (30% to 69% stenosis), and group 3 (> or =70% stenosis). PDA CFR was 2.62 +/- 0.25 in 17 patients in group 1, 2.33 +/- 0.32 in 9 patients in group 2, and 1.40 +/- 0.54 in 18 patients in group 3 (F = 41.83, p <0.0001). LAD CFR was 3.31 +/- 0.54 in 15 patients in group 1, 2.49 +/- 0.71 in 10 patients in group 2, and 1.12 +/- 0.49 in 19 patients in group 3 (F = 65.68, p <0.0001). A cut-off of <2 identified > or =70% stenosis in both of the arteries supplying the PDA and in the LAD. Noninvasive measurement of PDA CFR is feasible and may improve with technologic advancement and the use of selective adenosine receptor agonists, thus preventing hyperventilation.

Noninvasive coronary flow reserve assessed by transthoracic coronary Doppler ultrasound in patients with left anterior descending coronary artery stents

Noninvasive measurement of coronary flow reserve (CFR) (hyperemic/flow velocity ratio at rest) by transthoracic Doppler echocardiography showed normalization of flow in the left anterior descending (LAD) coronary artery early after stenting. We hypothesized that noninvasive CFR may reveal in-stent restenosis at follow-up. Therefore, we studied 134 patients, 0 to 72 months after successful proximal-middle LAD stenting, and 38 controls. LAD flow velocity was measured by transthoracic Doppler echocardiography during 90 seconds venous adenosine infusion (140 microg/kg/min). CFR was measured in diastole. According to angiography, patients who received stents were divided into 3 groups: group I, <50% LAD in-stent restenosis (n = 83); group II, nonsignificant (50% to 69%) LAD in-stent restenosis (n = 17); and group III, significant (> or = 70%) LAD in-stent restenosis (n = 34). LAD CFR was similar in group I and controls (2.90 +/- 0.58 vs 3.05 +/- 0.81; p = NS), it was slightly lower in group II (2.42 +/- 0.33) compared with controls and group I (p <0.001 vs both), and clearly abnormal (<2) in group III (1.38 +/- 0.48) compared with controls, and groups I and II (p <0.001). A CFR <2 had 91% sensitivity, 95% specificity, and 96% positive and 97% negative predictive values to detect significant stenosis in patients with LAD stents. Our data show that noninvasive Doppler assessment of CFR allows identification of significant LAD in-stent restenosis, based on a cut-off value of <2.

Coronary recanalization in anterior myocardial infarction: the open perforator hypothesis ☆

OBJECTIVE Patent perforators, noninvasively imaged by transthoracic color-Doppler echocardiography, may reflect adequate reperfusion in anterior myocardial infarction (MI). BACKGROUND The Thrombolysis In Myocardial Infarction (TIMI) classification may not fully reflect adequate myocardial reperfusion in MI. METHODS We studied 61 patients with anterior MI undergoing thrombolysis (n = 28), primary stenting (n = 20), or neither one (n = 13). High-resolution color-Doppler ultrasound was used to image the left anterior descending coronary artery (LAD) and perforators in four segments of the anterior-apical wall and to build a new recanalization score (RS). The TIMI flow was assessed by angiography. Wall motion score index (WMSI), ejection fraction (EF), end-diastolic volume index, and end-systolic volume index (ESVI) were measured by echocardiography at baseline and at three-month follow-up. Linear regression equations, considering RS or TIMI flow as independent variables, were compared among these functional recovery parameters. A multivariate linear model, predicting percent changes of WMSI, EF, or ESVI, was used to investigate the contribution of several clinical covariates along with RS and TIMI flow. RESULTS Sensitivity, specificity, and diagnostic accuracy of color-Doppler ultrasound in detecting LAD patency were 86%, 98%, and 97%, respectively. Mean and peak flow velocities discriminated (0.004 < p < 0.008) TIMI flow but not RS. Regression equations showed that RS discriminated better than TIMI flow recovery of ventricular function (p < 0.012). The RS was the best single multivariate predictor (p < 0.0001) of percent changes in WMSI, EF, and ESVI. CONCLUSIONS Transthoracic color-Doppler ultrasound detects an open LAD after MI. Perforators reflect adequate myocardial reperfusion and are early noninvasive markers of myocardial viability.

Combined pulmonary fibrosis and emphysema: 3D time-resolved MR angiographic evaluation of pulmonary arterial mean transit time and time to peak enhancement

PURPOSE To correlate conventional invasive pressure indexes of pulmonary circulation with pulmonary first-order arterial mean transit time (MTT) and time to peak enhancement (TTP) measured by means of three-dimensional time-resolved magnetic resonance (MR) angiography in patients with combined pulmonary fibrosis and emphysema (CPFE). MATERIALS AND METHODS The study was institutional review board approved. All subjects involved in the study provided written informed consent. Eighteen patients with CPFE were enrolled in this study. Thirteen healthy individuals matched for age and sex served as control subjects. Three-dimensional time-resolved MR angiography was performed by using a 3.0-T MR imager. Regions of interest (ROIs) were drawn manually on first-order pulmonary arteries. Within the ROIs, signal intensity-versus-time curves reflecting the first pass of the contrast agent bolus in the pulmonary vessels were obtained. MTT and TTP were calculated. Pulmonary arterial pressure and pulmonary capillary wedge pressure were measured with a double-lumen, balloon-tipped catheter that was positioned in the pulmonary artery. The mean pulmonary arterial pressure (mPAP) and the pulmonary vascular resistance (PVR) were determined. RESULTS MTT and TTP values were prolonged significantly in patients with CPFE compared with those in the control subjects (P < .001). Mean TTP and mean MTT correlated directly with mPAP and PVR index (P < .005). At multiple linear regression analysis, MTT was the only factor independently associated with PVR index and mPAP. CONCLUSION Three-dimensional time-resolved MR angiography enables determination of pulmonary hemodynamic parameters that correlate significantly with the pulmonary hemodynamic parameters obtained with invasive methods and may represent a complementary tool for evaluating pulmonary hypertension in patients with CPFE.

Clinical value of echocardiographic assessment of coronary flow reserve after left anterior descending coronary artery stenting in an unselected population

Background Transthoracic Doppler echocardiography is a valuable tool to measure coronary flow reserve (CFR) and detect in-stent restenosis (ISR) after percutaneous coronary angioplasty in selected series of patients. Objectives To assess the usefulness of coronary flow reserve measured by echocardiography in detecting significant (≥70%) ISR of the left anterior descending coronary artery in a large unselected population. Methods Two hundred and twenty-three patients (age 61 ± 10 years; 168 men) treated with left anterior descending stenting underwent CFR measurement by transthoracic Doppler echocardiography and venous adenosine infusion 24–72 h before control coronary angiography. Coronary-active drugs were continued, and patients with multiple risk factors and old anterior–apical myocardial infarction were included. Results Significant ISR occurred in 56 patients (25%). Patients with ISR had higher basal coronary flow velocity (27 ± 10 cm/s vs. 24 ± 7 cm/s; P < 0.002) and lower CFR (1.5 ± 0.5 vs. 2.7 ± 0.6; P < 0.0001) than those without ISR. A linear relation was found between ISR and CFR (r = −0.73; P < 0.0001) and remained significant after adjustment for blood pressure and heart rate (r = −0.74; P < 0.0001). A CFR less than two identified significant ISR (sensitivity 88%, specificity 88%, area under the curve = 0.943; P < 0.001). In a multivariate model of CFR prediction, myocardial infarction and heart rate were slightly contributory (ß = −0.19, P < 0.01; ß = −0.16, P < 0.03, respectively), whereas ISR had a large influence (ß = −0.66; P < 0.0001). The inverse correlation between ISR and CFR persisted in patients with myocardial infarction (r = −0.64; P < 0.0001) and in those treated with β-blockers (r = −0. 71; P < 0.0001). Conclusion Echocardiographic measurement of CFR detects significant left anterior descending ISR in unselected patients with multiple risk factors, old anterior–apical myocardial infarction, and taking β-blockers.

Successful Coronary Stent Retrieval From a Pedal Artery

The purpose of this article is to report complications from a coronary drug-eluting stent lost in the peripheral circulation. We report the case of successful retrieval of a sirolimus coronary stent from a pedal artery in a young patient who underwent coronary angiography for previous anterior myocardial infarction. Recognition of stent embolization requires adequate removal of the device to avoid unwelcome clinical sequelae.

Local immune activity in acute coronary syndrome: oxLDL abrogates LPS-tolerance in mononuclear cells isolated from culprit lesion

BACKGROUND OxLDL plays a major role in the initiation and progression of atherosclerotic lesions even though further factors are needed to promote fibrous cap rupture and thrombotic occlusion of the arterial lumen. Pathogens have been implicated in this process but it remains unclear how they can cooperate with oxLDL in amplifying the destructive inflammatory response. OBJECTIVE To phenotypically analyze culprit coronary inflammatory cells, evaluate their responsiveness to endotoxins and ascertain whether oxLDL alters the sensitivity of coronary mononuclear cells to bacterial components. METHODS Mononuclear cells isolated from culprit and non-culprit coronary blood samples of patients with ST-segment elevation myocardial infarction (STEMI) and controls were analyzed for cell-specific surface markers and cytokines by flow-cytometry. RESULTS AND CONCLUSIONS CD14+ cells contained elevated levels of TLR4, expressed high CD80, and produced huge amounts of inflammatory cytokines in response to LPS. Using a well-established model of endotoxin tolerance, we next showed that mononuclear cells isolated from control coronary artery, but not from culprit coronary artery, were tolerant to LPS, but pre-treatment of such cells with oxLDL abrogated LPS tolerance. Flow-cytometry analysis also showed that IL-17A, IL-21 and IFN-γ were over-produced by CD4+ and CD56+ cells isolated from the culprit coronary artery. All this data indicate that monocytes circulating in the culprit coronary artery of patients with STEMI are primed to synthesize high levels of inflammatory cytokines and suggest that oxLDL can amplify the inflammatory response of such cells to endotoxins.

Large coronary aneurysm following laser angioplasty of the left anterior descending coronary artery.

Coronary aneurysm is a rare complication after coronary excimer laser angioplasty. A 45-year-old woman underwent laser angioplasty and bare metal direct stenting of the proximal segment of the left anterior descending artery (LAD); after 3 months, angiographic follow-up showed significant ostial stenosis of the LAD with a large sacciform aneurysm and diffuse intrastent restenosis.

Prediction of long-term ischemic events by noninvasively assessed coronary flow reserve.

Background Coronary flow reserve (CFR) by adenosine echocardiography in left anterior descending (LAD) or posterior descending coronary arteries may predict clinical outcome. Methods We used models accounting (Coxs model) or not (logistic regression and neural network) for time to event and either considered (forced models) or not (stepwise logistic regression and neural network models) all among 21 covariates to predict 1-year composite events after LAD CFR. Results There were 553 consecutive patients with coronary artery disease (CAD): 89 patients had also posterior descending CFR. During 1-year follow-up 328 patients were event-free, 35 had composite ischemic events and 190 underwent short-term revascularization. LAD and posterior descending CFR (respectively, 1.53 ± 0.83, N = 225 and 1.84 ± 0.80, N = 42) were significantly (P < 0.0001) lower in patients with events (or with revascularization following CFR measurement) than in those without (respectively, 3.13 ± 0.84, N = 328, and 2.53 ± 0.72, N = 47). Using LAD CFR as a continuous covariate, by both forced Coxs and logistic regression, coefficients (t values, respectively, −14.11 and −10.19) were significant (both P < 0.00001) to predict outcome. Global predictive accuracies by neural network, adopting a receiver operating characteristic areas under the curve (ROC) assessment, were excellent (>0.91) and the role of LAD CFR among predictors was overwhelming. Other indices of myocardial ischemia and the presence of coronary stenoses or previous infarction did not modify the multivariable predictive role of LAD CFR. When patients with revascularization were discounted, the LAD CFR predictive role was the same. Conclusions Thus, adenosine echocardiography-based LAD CFR predicts 1-year composite ischemic events in patients with CAD, independent of the multivariable model adopted. Posterior descending CFR also has a role.