Among patients with TIMI flow grade 3, the extent of microvascular damage, detected and quantitated by MCE, is the most powerful independent predictor of LV remodeling after STEMI as compared with persistent ST-segment elevation and myocardial blush grade.

AimsFew data are available on the extent and prognostic value of reverse left ventricular remodelling (r-LVR) after ST-elevation acute myocardial infarction (STEMI). We sought to evaluate incidence, major determinants, and long-term clinical significance of r-LVR in a group of STEMI patients treated with primary percutaneous coronary intervention (PPCI). In particular, the role of preserved microvascular flow within the infarct zone in inducing r-LVR has been investigated.Methods and resultsSerial echocardiograms (2DE) and myocardial contrast study were obtained within 24 h of coronary recanalization (T1) and at pre-discharge (T2) in 110 reperfused STEMI patients. Follow-up 2DE was scheduled after 6 months (T3). Two-year clinical follow-up was obtained. Reverse remodelling was defined as a reduction >10% in LV end-systolic volume (LVESV) at 6 months follow-up. r-LVR occurred in 39% of study population. At multivariable analysis, independent predictors of r-LVR were an effective microvascular reflow within the infarct zone, the in-hospital improvement of myocardial perfusion, an initial large LVESV, and a short time to reperfusion. Cox analysis identified r-LVR as the only independent predictor of 2-year event-free survival. Combined events rate was significantly higher among patients without compared to those with r-LVR (log-rank test P < 0.05).Conclusionr-LVR frequently occurs in STEMI patients treated with PPCI and it is an important predictor of favourable long-term outcome. A preserved microvascular perfusion within the infarct zone is the major determinant of r-LVR.

Background:The best timing for coronary angiography (immediate vs early) in patients with acute non-STelevation myocardial infarction (NSTEMI) is controversial. Hypothesis: Evaluate in NSTEMI patients the effects of an immediate compared to an early invasive strategy on microvascular damage, myocardial perfusion, and infarct size. Methods: We randomized 54 consecutive patients with first episode of NSTEMI: 27 patients (22 males, age 58.8 ± 9.4 years, group A) underwent immediate (≤6 hours) percutaneous coronary intervention (PCI) with a double bolus of eptifibatide, and 27 patients (24 males, age 59.7 ± 9.8 years, P = 0.72, group B) underwent early (7-72 hours) PCI with upstream eptifibatide. Microvascular damage was evaluated at predischarge by myocardial contrast echocardiography, and the contrast defect length was calculated.Results: There were no significant differences in pre-PCI myocardial blush grade (MBG) (41% MBG 0 or 1 in group A vs 37% MBG 0 or 1 in group B, P = 0.78), in post-PCI MBG (7.4% MBG 0 or 1 in both groups, P = 1.00), and in contrast defect length (4.5% in group A vs 2.8% in group B, P = 0.56). However, group A showed a significant reduction in creatine kinase myocardial band isoenzyme peak (26 ± 26 ng/mL in group A vs 69 ± 79 ng/mL in group B, P = 0.01) and in troponin T peak (0.84 ± 1.2 ng/mL in group A vs 1.8 ± 2.1 ng/mL in group B, P = 0.048). Conclusions:In patients with NSTEMI treated with eptifibatide, immediate PCI is associated with less increase in myonecrosis markers compared with PCI within 72 hours. There were no significant differences in myocardial perfusion between the 2 strategies. IntroductionIn patients with acute non-ST-elevation myocardial infarction (NSTEMI), an early invasive strategy with coronary angiography (CA) and subsequent revascularization through percutaneous coronary intervention (PCI) is associated with reduced rates of death and myocardial infarction (MI) in comparison with a conservative strategy. 1 Guidelines for the treatment of patients with acute coronary syndromes (ACS) recommend an early (≤72 hours) invasive strategy for patients admitted with diagnosis of NSTEMI. 2 Excluding conditions requiring emergency interventions (refractory angina, shock, and life-threatening arrhythmias), controversy remains regarding the optimal timing between hospital admission and the invasive procedure, with 2 different alternatives for the invasive approach:

The introduction of stable microbubble contrast agents and technological advances have recently made it feasible to perform quantitative measurements of microvascular damage by myocardial contrast echocardiography (MCE). Qontrast is a new software system far such measurements. It includes physiological filters, global rescale, regional rescale, automatic myocardial tracking, manual ECG trigger and parametric imaging. Qontrast was tested on 5 pigs given sulphur hexafluoride bubbles (I ml/min) and fluorescent microspheres (reference) after the induction of 50% and 100% stenosis of left anterior descending coronary artery. The image sequences were repeated four times using different ultrasound (US) equipment. A close correlation was found between the ratio risk area/control area by microspheres and the equivalent ratio risk area/control area (Sl x beta) by MCE, being approximately 0.9 far any contrast modality tested. Parametric MCE and SPELT were compared in 12 patients with recent myocardial infarction, including 119 segments. Agreement amounted to 83% (kappa: 0.53 far peak SI and 0.55 far SI x beta). The sensitivity and specificity of peak SI far detecting abnormal segmental tracer uptake were 67% and 88%; the values far Sl x beta were 70% and 87%. Parametric MCE is a promising imaging technique far the assessment of myocardial perfusion in patients with suspected or known coronary artery disease.

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New technologies and the availability of new echo-contrast agents have resulted in advances of diagnostic and prognostic indications of left ventricular opacification (LVO) and myocardial perfusion. The clinical diagnostic value of ultrasound contrast media for LVO and its impact on the clinical decision-making process has been demonstrated in several studies. Recent research aims at developing new quantitative software to improve the delineation of the endocardial border, to assess 3D myocardial perfusion for more accurate regional/global LV function measurements, and to evaluate 4D intra-cardiac flow dynamics. Furthermore, a general consensus has been reached on the incremental value of myocardial contrast echocardiography (MCE) for obtaining additional information in both chronic and acute coronary artery disease (CAD) patients and on the possibility to make quantitative measurements of microvascular damage. Q-contrast is a new software system which provides quantitative measurements to generate parametric images of microcirculatory flow. In a research project including 120 patients, Q-contrast software has been tested to assess the role of contrast in AMI (Acute Myocardial Infarction Contrast Imaging (A.M.I.C.I. Study); good agreement between parametric MCE and SPECT has been found. Preliminary results further confirm that quantitative MCE may provide additional clinical value over qualitative information for the assessment of LV function and of the effects of coronary artery disease on the myocardial microcirculation (viability, ischemia or infarct).

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