Mauro Cadeddu

Validation of a new noninvasive method (contrast-enhanced transthoracic second harmonic echo Doppler) for the evaluation of coronary flow reserve: Comparison with intracoronary Doppler flow wire

OBJECTIVES We tested the hypothesis that coronary flow reserve (CFR) in the left anterior descending coronary artery (LAD) as assessed by a new noninvasive method (contrast-enhanced transthoracic second harmonic echo Doppler) is in agreement with CFR measurements assessed by intracoronary Doppler flow wire. BACKGROUND Contrast-enhanced transthoracic second harmonic echo Doppler is a novel noninvasive method to detect blood flow velocity and reserve in the LAD. However, it has not yet been validated versus a gold-standard method. METHODS Twenty-five patients undergoing CFR assessment in the LAD by Doppler flow wire were also evaluated by contrast-enhanced transthoracic Doppler to record blood flow in the distal LAD at rest and during hyperemia obtained by adenosine i.v. infusion. In five patients CFR was evaluated twice (before and after angioplasty). RESULTS As a result of the combined use of i.v. contrast and second harmonic Doppler technology, feasibility in assessing coronary flow reserve equaled 100%. The agreement between the two methods was high. In fact, in all but five patients the maximum difference between the two CFR measurements was 0.38. Overall, the prediction (95%) interval of individual differences was -0.69 to +0.72. Reproducibility of CFR measurements was also high. The limits of the agreement (95%) between the two measurements were -0.32 to +0.32. CONCLUSIONS Coronary flow reserve in the LAD as assessed by contrast-enhanced transthoracic echo Doppler along with harmonic mode concurs very closely with Doppler flow wire CFR measurements. This new noninvasive method allows feasible, reliable and reproducible assessment of CFR in the LAD.

Detection of coronary restenosis aftercoronary angioplasty by contrast-enhanced transthoracic echocardiographic Doppler assessment of coronary flow velocity reserve

OBJECTIVES This study sought to evaluate the diagnostic potential of contrast-enhanced transthoracic echocardiography (CE-TTE) during adenosine infusion, a noninvasive method for evaluating coronary flow reserve (CFR), in detecting restenosis after successful percutaneous transluminal coronary angioplasty (PTCA). BACKGROUND Restenosis is the most important limitation of PTCA, and CFR can be impaired in patients with angiographically documented significant coronary stenosis. METHODS We performed 6 +/- 2 months of follow-up of 53 patients after successful elective PTCA in the left anterior descending coronary artery (LAD). Coronary angiography was performed at the end of the planned follow-up period or even before, if clinically indicated. Thus, of the 53 patients, a total of 63 angiographic studies were performed; CE-TTE assessment of CFR was achieved before each of the 63 angiographic studies. RESULTS Coronary angiography revealed the presence of restenosis (defined as >50% stenosis at a previous PTCA site) in 32 angiographic examinations (group A) and no coronary restenosis in the remaining 31 examinations (group B). Coronary flow reserve was significantly reduced in group A compared with group B (1.65 +/- 0.5 vs. 3.17 +/- 0.8, p < or = 0.001). A noninvasive CFR value < or = 2 was 93% specific and 78% sensitive for detecting significant restenosis, with positive and negative diagnostic accuracies of 92% and 80%, respectively. CONCLUSIONS Noninvasive CFR assessment by CE-TTE is an accurate method of monitoring significant restenosis in the LAD when following up patients submitted to elective PTCA.

Detection, location, and severity assessment of left anterior descending coronary artery stenoses by means of contrast-enhanced transthoracic harmonic echo Doppler

AIMS Contrast-enhanced second harmonic Doppler (ED) is a new ultrasound modality that increases the feasibility of recording blood flow velocity (BFV) in the left anterior descending coronary artery (LAD) using a transthoracic approach. Blood flow velocity convective acceleration is a reliable marker of coronary stenosis and can be used to assess the percentage area reduction at the stenosis site by applying the continuity equation. To detect, locate, and assess the severity of significant stenosis throughout the LAD by means of an ED recording of BFV acceleration at the stenosis site. METHODS AND RESULTS Fifty-three consecutive patients undergoing coronary angiography (CA) underwent a colour-guided pulsed-wave ED recording of BFV in the proximal/mid and distal portions of the LAD, and maximal and reference BFV was obtained in each of the two arterial segments. Maximal velocity was much higher in the diseased segments (>or=50% lumen narrowing) than in the normal segments (143 +/- 84 vs. 38 +/- 20 cm/s; P < 0.001); as the reference velocity was similar (37 +/- 13 vs. 31 +/- 12; P = 0.03), the percentage increase in velocity was also higher (290 +/- 233 vs. 20 +/- 37%; P < 0.001). Using a cut-off value of an 82% increase in velocity, sensitivity and specificity vs. CA was, respectively, 86 and 95%. The reduction in the percentage area of stenosis calculated using the continuity equation agreed with that determined by means of quantitative CA (r = 0.7). CONCLUSION Blood flow velocity evaluation in the LAD by means of transthoracic ED is feasible and reliable in detecting, locating, and assessing the severity of LAD stenosis.

Early Noninvasive Evaluation of Coronary Flow Reserve after Angioplasty in the Left Anterior Descending Coronary Artery Identifies Patients at High Risk of Restenosis at Follow-Up

BACKGROUND Coronary restenosis is the most important clinical limitation after percutaneous coronary intervention (PCI), and coronary flow reserve (CFR) is reduced in the presence of significant coronary stenosis. This study evaluated whether detection of early reduction of Doppler echocardiographically derived CFR in the left anterior descending coronary artery can identify patients at high risk for developing restenosis after successful PCI. METHODS Doppler echocardiographically derived CFR was studied in 124 consecutive patients at 1-month and 6-month follow-up after PCI in the left anterior descending coronary artery, together with coronary angiography. RESULTS Restenosis was detected in 39 angiographic examinations (group A) and no coronary restenosis in the remaining 85 (group B) at 6 months. At 1 month, CFR was reduced in group A compared with group B (P < .0001), and a significant reduction of CFR in group A (P < .0001) but not in group B (P = .89) was detected at 6 months. CFR ≤ 2.5 at 1 month was 67% sensitive and 87% specific for predicting significant restenosis, with positive and negative predictive values of 67% and 87%, respectively. CONCLUSIONS CFR ≤ 2.5 detected 1 month after PCI in the left anterior descending coronary artery has the potential to identify patients at higher risk for developing coronary restenosis and indicates the need for close clinical follow-up.

Felodipine Improves the Anti-Ischaemic Effect of Metoprolol in Stable Effort-Induced Angina

SummaryThe anti-ischaemic effects of sustained release felodipine 10 mg/day, metoprolol 200 mg/day and both drugs together were assessed in 16 male patients with stable effort-induced angina pectoris in a randomised double-blind crossover study. At the end of each 7-day treatment period, patients performed a maximum symptom-limited cycloergometer exercise test. All 3 active regimens significantly (p < 0.05) increased the ischaemic threshold (time to 1mm ST-segment depression) and exercise capacity (time to angina pain or exhaustion), and decreased ST-segment depression at maximum common workload vs placebo. The combination regimen produced a significantly greater effect on ischaemic threshold and ST-segment depression at maximum workload and maximum common workload than felodipine alone, and a greater effect on ST-segment depression at maximum common workload than metoprolol alone. Rate-pressure product at ischaemic threshold and maximum workload was increased by felodipine and decreased by metoprolol or the combination regimen. Thus, the combination of felodipine with metoprolol resulted in greater anti-ischaemic activity than that observed with either drug alone, reflecting their different, but complementary, mechanisms of action.

[The network for acute coronary syndromes in the metropolitan area of Cagliari (Italy): management of ST-elevation myocardial infarction, reperfusion time, and adherence to guidelines].

BACKGROUND An integrated network for the management of acute ST-elevation myocardial infarction (STEMI) allows a pre-hospital diagnosis and facilitates the best strategy to provide the most effective reperfusion therapy. This study aims to assess the network impact on timing and mode of reperfusion in the metropolitan area of Cagliari. METHODS From January 1, 2008 to December 31, 2010 all patients affected by STEMI with symptom onset <12h were enrolled. We evaluated modality of hospital access, reperfusion therapies, and time for avoidable delay. The first medical contact-to-balloon time (FMC-to-balloon) was compared between patients without ECG transmission (No-ECG group) and those with ECG transmission and direct transport to the cath-lab (Cath-Lab-ECG group) or the emergency room/intensive cardiac care unit (ER/ICCU-ECG group). RESULTS Out of 622 patients enrolled, 324 (52.1%) arrived to hospital by emergency medical systems. In this group a pre-hospital diagnosis was made in 79.3% of cases (n = 257); among them, 138 patients (53.7%) had a direct access to cath-lab, 99 to ICCU (38.5%), and 20 (7.8%) to ER. In the whole study population an urgent coronary angiography was performed in 612 patients (98.4%) and a primary percutaneous coronary intervention (p-PCI) in 589 (96.2%). In the Cath-Lab-ECG group the FMC-to-balloon was 89 ± 29 min (median 87 min, interquartile range 72-100), significantly lower than in the ER/ICCU-ECG group [122 ± 39 min (115 min)] and the No-ECG group [150 ± 54 min (139 min)] (p<0.01). A FMC-to-balloon ≤90 min was achieved in 66.4% of Cath-Lab-ECG patients, 22.1% of ER/ICCU-ECG patients, and 8.3% of No-ECG patients (Cath-Lab-ECG vs ER/ICCU-ECG, p<0.01). CONCLUSIONS Our results show that an integrated network provides a pre-hospital diagnosis in the majority of STEMI. However, only a direct transport to the cath-lab allows to achieve a FMC-to-balloon ≤90 min in a large proportion of patients. Out of this condition, adherence to guideline-recommended time of ≤90 min is significantly lower.