Recovery Of Regional Wall Motion Research Articles

Usefulness of serial post-systolic shortening by speckle tracking echocardiography to predict major adverse cardiovascular events and segmental function improvement after acute myocardial infarction.

The aim is to determine whether serial post-systolic shortening (PSS) using speckle tracking echocardiography (STE) could predict major adverse cardiovascular events (MACE), especially symptom-driven infarct-related artery (IRA) revascularization and improvement in segmental function in post-myocardial infarction patients. Ninety-four patients (average age 61.1 ± 12.5 y, 84 [84.9%] male) with new-onset acute myocardial infarction were enrolled. Serial echocardiography was performed during the initial presentation, and at 3, 6 and 12 months after admission. PSS, strain and systolic strain rate were calculated using STE. Improvement in segmental function was defined as a decrease of ≧1 grade in wall motion score. During the follow-up (29.4 ± 12.7months), 22 patients (23.4%) had MACE and 17 patients had symptom-driven IRA revascularization. In multivariate model, PSS at 3 months was independently predictive for symptom-driven IRA revascularization (Hazard ratio (HR) = 0.5, 95% CI = 0.26-0.97) and for MACE (HR = 0.4, 95% CI = 0.24-0.67) (p < 0.05). Segmental function improvements were found in 255 segments (66.1%) and ROC curve analyses showed that AUC (95% CI) of the initial PSS was 0.7(0.65-0.77) (cut-off values = -1.08, sensitivity = 58%, specificity = 73% specificity). Post-systolic shortening at 3 months is an independent predictor for symptom-driven IRA revascularization and MACE. Regional wall motion recovery also could be predicted by initial PSS. Serial assessment of two-dimensional STE should be investigated in post-myocardial infarction patients in the future.

5964Hybrid PET/MR imaging for the prediction of left ventricular (LV) recovery after revascularisation of chronic total occluded coronaries

Abstract Background Percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) represents one of the major challenges in interventional cardiology. Physicians are still reluctant in referring for PCI, assuming non viability of the myocardium subtended by the CTO. Data are controversial in assessing the improvement of left ventricular (LV) wall motion after revascularisation and the prognostic value of viability testing to guide patient selection. Purpose The aim of this study was to determine, whether hybrid fluorodeoxyglucose positron emission tomography/magnetic resonance (FDG PET/MR) imaging allows a more accurate prediction of LV regional wall motion recovery after successful PCI of CTOs in comparison to PET or MR alone. Methods We enrolled 49 consecutive symptomatic patients with CTO and evidence of wall motion abnormality in the corresponding CTO-territory. All patients underwent hybrid FDG PET/MR imaging as semi-quantitative assessment of myocardial viability - glucose metabolism in PET and late gadolinium enhancement (LGE) transmurality in MR – prior of PCI of the CTO. Follow-up MRI was performed in 23 patients 3–6 months after successful revascularisation to evaluate wall motion changes. Results We assessed viability in 124 myocardial segments subtended by a CTO in 23 patients with successful PCI who underwent serial imaging. Segments with wall motion abnormality at baseline (n=80) were analysed. Most of these segments (n=54, 68%) were concordantly assessed viable by PET and MR, conversely only 2 (2%) segments were assessed non-viable by both imaging techniques. However, almost one third of the segments showed discordant patterns of viability either PET not viable/ MR viable (3 (4%) segments) or PET viable/ MR not viable (21 (26%) segments): particularly the latter revealed a significant wall motion improvement (p=0.033). The combination of PET and MR showed a fair accuracy in predicting myocardial segments with wall motion improvement after CTO revascularisation (PET/MR area under ROC curve (AUC) 0.72, SE 0.07, p=0.002), which was superior to MR-LGE (AUC=0.66, SE 0.09) and FDG-PET (AUC=0.58, SE 0.10) alone (Figure). Comparisons of ROC curves Conclusion Hybrid PET/MR imaging prior to successful CTO showed a better performance than PET or MR alone in predicting regional improvement of disturbed wall motion. The complimentary information derived from both modalities may particularly help to identify small amounts of viable epicardial myocardium within large scars which can improve contractility after CTO-revascularisation.

PET/MRI early after myocardial infarction: evaluation of viability with late gadolinium enhancement transmurality vs. 18F-FDG uptake.

F-18 fluorodeoxyglucose (FDG) myocardial PET imaging is since more than two decades considered to delineate glucose utilization in dysfunctional but viable cardiomyocytes. Late gadolinium enhancement (LGE) MRI was introduced more than a decade ago and identifies increased extravascular space in areas of infarction and scar. Although the physiological foundation differs, both approaches are valuable in the prediction of functional outcome of the left ventricle, but synergistic effects are yet unknown. We aimed to compare the improvement of LV function after 6 months based on the regional FDG uptake and the transmurality of scar by LGE in patients early after acute myocardial infarction (AMI). Twenty-eight patients with primary AMI underwent simultaneous PET/MRI for assessment of regional FDG uptake and degree of LGE transmurality 5-7 days after PCI. Follow-up by MRI was performed in 20 patients 6 months later. Myocardium was defined 'PET viable' based on the established threshold of ≥ 50% FDG uptake compared with remote myocardium or as 'MRI viable' when LGE transmurality of ≤ 50% was present. Regional wall motion was measured by MRI. Ninety-five dysfunctional segments were further analysed regarding regional wall motion recovery. There was a substantial intermethod agreement for segmental LGE transmurality and reduction of FDG uptake (κ = 0.65). 'PET viable' and 'MRI viable' segments showed a lower wall motion abnormality score (PET: initial: 1.4 ± 0.6 vs. 1.9 ± 0.8, P < 0.008; follow-up: 0.5 ± 0.7 vs. 1.5 ± 1.0, P < 0.0001; MRI: initial: 1.5 ± 0.6 vs. 2.0 ± 0.8, P < 0.002; follow-up: 0.7 ± 0.8 vs. 1.6 ± 1.0, P < 0.0001) and a better regional wall motion improvement (PET: -0.9 ± 0.7 vs. -0.4 ± 0.7, P < 0.0007; MRI: -0.8 ± 0.7 vs. -0.4 ± 0.7, P < 0.009) compared with 'PET non-viable' or 'MRI non-viable' segments, respectively. Eighteen per cent of the dysfunctional segments showed discrepant findings ('PET non-viable' but 'MRI viable'). At follow-up, the regional wall motion of these segments was inferior compared with 'PET viable/MRI viable' segments (1.1 ± 0.8 vs. 0.5 ± 0.7, P < 0.01), had an inferior functional recovery (-0.5 ± 0.6 vs. -0.9 ± 0.7, P < 0.03), but showed no difference compared with concordant 'PET non-viable/MRI non-viable' segments. The simultaneous assessment of LGE and FDG uptake using a hybrid PET/MRI system is feasible. The established PET and MRI 'viability' parameter prior to revascularization therapy also predicts accurately the regional outcome of wall motion after AMI. In a small proportion of segments with discrepant FDG PET and LGE MRI findings, FDG uptake was a better predictor for functional recovery.

Autologous CD133+ bone marrow cells and bypass grafting for regeneration of ischaemic myocardium: the Cardio133 trial

Intra-myocardial transplantation of CD133(+) bone marrow stem cells (BMC) yielded promising results in clinical pilot trials. We now performed the double-blinded, randomized, placebo-controlled CARDIO133 trial to determine its impact on left ventricular (LV) function and clinical symptoms. Sixty patients with chronic ischaemic heart disease and impaired LV function (left ventricular ejection fraction, LVEF <35%) were randomized to undergo either coronary artery bypass grafting (CABG) and injection of CD133(+) BMC in the non-transmural, hypokinetic infarct border zone (CD133), or CABG and placebo injection (placebo). Pre-operative LVEF was 27 ± 6% in CD133 patients and 26 ± 6% in placebo patients. Outcome was assessed after 6 months, and the primary endpoint was LVEF measured by cardiac magnetic resonance imaging (MRI) at rest. The incidence of adverse events was similar in both groups. There was no difference in 6-min walking distance, Minnesota Living with Heart Failure score, or Canadian Cardiovascular Society (CCS) class between groups at follow-up, and New York Heart Association class improved more in the placebo group (P = 0.004). By cardiac MRI, LVEF at 6 months was 33 ± 8% in the placebo group and 31 ± 7% in verum patients (P = 0.3), with an average inter-group difference of -2.1% (95% CI -6.3 to 2.1). Systolic or diastolic LV dimensions at 6 months were not different, either. In the CD133 group, myocardial perfusion at rest recovered in more LV segments than in the placebo group (9 vs. 2%, P < 0.001). Scar mass decreased by 2.2 ± 5 g in CD133(+) patients (P = 0.05), but was unchanged in the placebo group (0.3 ± 4 g, P = 0.7; inter-group difference in change = 2 g (95% CI -1.1 to 5)). By speckle-tracking echocardiography, cell-treated patients showed a better recovery of regional wall motion when the target area was posterior. Although there may be some improvements in scar size and regional perfusion, intra-myocardial injection of CD133(+) BMC has no effect on global LV function and clinical symptoms. Improvements in regional myocardial function are only detectable in patients with posterior infarction, probably because the interventricular septum after anterior infarction is not accessible by trans-epicardial injection. This trial was registered at http://www.clinicaltrials.gov under NCT00462774.

Ultrasonic Strain Versus Coronary Flow Velocity Pattern for Predicting Regional Wall Motion Recovery After Primary Coronary Intervention for Acute Myocardial Infarction

Strain Doppler echocardiography can detect regional myocardial dysfunction after acute myocardial infarction (AMI). The aim of this study was to assess the utility of strain in predicting regional wall motion recovery after AMI compared with the coronary flow velocity pattern. Thirty-three patients with anterior AMIs undergoing successful coronary intervention were included. Longitudinal myocardial strain and coronary flow velocity were measured <24 hours after coronary intervention. Regional wall motion was analyzed by the anterior wall motion score index (A-WMSI). End-systolic strain (r = 0.72, P < .0001), peak strain (r = 0.58, P < .005), and corrected time to peak strain (the time delay from end-systolic to peak strain divided by the RR interval) (r = 0.80, P < .0001) showed good correlations with A-WMSI at 4 weeks. Similarly, diastolic deceleration time was significantly correlated with A-WMSI at 4 weeks (r = 0.69, P < .0001). The diagnostic value in predicting wall motion recovery was compared using a receiver operating characteristic curve. The area under the curve of corrected time to peak strain tended to be larger than that of diastolic deceleration time (0.94 +/- 0.04 vs 0.86 +/- 0.06). Strain can predict left ventricular wall motion recovery in patients with AMIs after coronary intervention comparable with predictions using the coronary flow velocity pattern.

Usefulness of Ultrasonic Strain Measurements to Predict Regional Wall Motion Recovery in Patients With Acute Myocardial Infarction After Percutaneous Coronary Intervention

Ultrasound Quarterly: September 2007 - Volume 23 - Issue 3 - p 197 doi: 10.1097/01.ruq.0000288149.57503.2e

Usefulness of Ultrasonic Strain Measurements to Predict Regional Wall Motion Recovery in Patients With Acute Myocardial Infarction After Percutaneous Coronary Intervention

Strain Doppler echocardiography can detect systolic regional myocardial dysfunction. This study assessed whether strain could predict recovery of regional left ventricular function in patients with acute myocardial infarction (AMI) after percutaneous coronary intervention. Forty-three patients with anterior AMI undergoing successful percutaneous coronary intervention of the left anterior descending coronary artery were studied. Longitudinal myocardial strain was measured at the left anterior descending coronary artery territory in the apical long-axis view within 24 hours after percutaneous coronary intervention. Regional wall motion was analyzed by the anterior wall motion score index (A-WMSI). Viable myocardium was defined as a decrease < or = 2.0 in A-WMSI. Patients were categorized as A-WMSI at 4 weeks into a viable group (n = 24) and a nonviable group (n = 19). End-systolic strain and peak strain were significantly lower in the nonviable group than in the viable group (-4.8 +/- 4.8% vs -9.9 +/- 4.7 %, p <0.005; -9.9 +/- 4.6 vs -13.5 +/- 4.1 %, p <0.05). Moreover, corrected time to peak strain (cTPS; time delay from end-systolic to peak strain/RR interval) was significantly longer in the nonviable group than in the viable group (0.19 +/- 0.04 vs 0.13 +/- 0.03, p <0.0001). For prediction of viable myocardium, cTPS <0.15 had a sensitivity of 95% and a specificity of 85%. In conclusion, strain, especially cTPS, is useful for predicting recovery of regional left ventricular function in patients with AMI after percutaneous coronary intervention.

Resting 12-lead electrocardiogram as a reliable predictor of functional recovery after recanalization of chronic total coronary occlusions

A major goal of revascularization is the recovery of left ventricular (LV) function. Nuclear imaging techniques are widely used for detecting recovery of function with a good sensitivity, but only moderate specificity. Predictors of recovery in chronic total coronary occlusions (CTO) are not investigated. The 12-lead-resting electrocardiogram (ECG) is a predictor of LV recovery after successful recanalization of CTO. Successful recanalization of CTO was performed in 127 patients. Of these, 62 patients, who constitute the study group, had impaired regional wall motion prior to recanalization. The 12-lead resting ECG was evaluated for Q-wave areas and parameters of QT dispersion. Impairment of regional wall motion was evaluated by LV angiogram at baseline and at follow-up. Angiographic follow-up after 5 +/- 1.4 months documented reocclusion in eight patients. Complete follow-up with a patent coronary artery and an ECG without bundle-branch block was available in 43 patients. Wall motion severity index (WMSI) improved from -2.92 +/- 0.28 to -1.34 +/- 0.61 (p < 0.001) in patients without Q waves, whereas it was unchanged in patients with Q waves (-3.01 +/- 0.30 and -2.81 +/- 0.32). Absence of Q waves at baseline predicted recovery of regional wall motion with 89% sensitivity and 67% specificity. Positive predictive value for recovery was 68% in patients without Q waves, but only 11% in patients with Q waves. In multivariate analysis, only absence of Q waves predicted improvement in WMSI (p = 0.01). In patients with recanalization of CTO, recovery of regional wall motion is reliably predicted by analysis of the resting 12-lead ECG for pathologic Q waves.

Evaluation of Transmural Myocardial Perfusion by Ultra-Harmonic Myocardial Contrast Echocardiography in Reperfused Acute Myocardial Infarction

The transmural distribution of myocardial perfusion is important for predicting the contractile reverse of an infarcted wall in reperfused acute myocardial infarction (AMI). Evaluating transmural myocardial perfusion by myocardial contrast echocardiography (MCE) could predict the long-term recovery of left ventricular (LV) function. The study group comprised 20 consecutive patients with a first-episode anterior AMI with total occlusion of the proximal left anterior descending artery, who underwent successful percutaneous coronary intervention within 24 h of onset. MCE was performed on the 15th day after the onset, using ultraharmonic gray-scale imaging with intermittent end-systolic triggering every 4 beats or every 6 beats. Regions of interest were placed over both the endocardial and epicardial region at the mid-septal level. Regional wall motion (RWM) of the infarcted anterior wall and global LV function were assessed by 2-dimensional echocardiography and left ventriculography in both the acute and chronic phase. The transmural distribution of myocardial perfusion by MCE demonstrated a significant relation with RWM score index (r = 0.75, p = 0.0004). Recovery of RWM and LV ejection fraction (LVEF) at 6 months after reperfusion was significantly greater in the group with good perfusion of the epicardium according to MCE than in the poor perfusion group [RWM (SD/cord); -1.23+/-0.91 vs -3.51+/-0.84, p = 0.001, LVEF (%); 63.8+/-10.4 vs 47.0+/-3.4, p = 0.04]. Assessing the transmural distribution of myocardial perfusion by MCE can predict the long-term recovery of LV function after a reperfused AMI.

Glucagon-like peptide-1 limits myocardial stunning following brief coronary occlusion and reperfusion in conscious canines.

We have recently demonstrated the benefits of glucagon-like peptide-1 (GLP-1) in enhancing regional and global myocardial function after reperfusion in the clinical setting of acute myocardial infarction. We hypothesized that GLP-1 facilitates recovery from myocardial stunning after an ischemic event. To investigate this, we administered GLP-1 (1.5 pmol/kg/min) to six dogs undergoing 10-min occlusion of the left circumflex coronary artery, followed by 24-h reperfusion. We compared the responses of coronary blood flow and regional thickening of the posterior wall with a group of eight vehicle-treated dogs undergoing the same occlusion-reperfusion protocol. Although recovery of coronary blood flow was identical, regional wall motion recovery occurred significantly ((*)p < 0.05) earlier (92 +/- 4 versus 57 +/- 5%(*) at 15 min) and was complete in the GLP-1-treated dogs, whereas residual contractile dysfunction persisted in the control group (99 +/- 4 versus 78 +/- 3%(*) at 24 h). This phenomenon was independent of changes in systemic hemodynamics or global systolic function. However, isovolumic left ventricular relaxation improved significantly in GLP-1-treated dogs. GLP-1 caused an insulinotropic effect, but no hypoglycemia. We conclude that GLP-1 enhances recovery from ischemic myocardial stunning after successful reperfusion.

1080-42 Resting 12-lead electrocardiogram as a reliable predictor of functional recovery after recanalization of chronic total coronary occlusions

Hypothesis:The 12-lead-resting electrocardiogram (ECG) is a predictor of LV recovery after successful recanalization of CTO. Methods:Successful recanalization of CTO was performed in 127 patients. Of these, 62 patients, who constitute the study group, had impaired regional wall motion prior to recanalization. The 12-lead resting ECG was evaluated for Q-wave areas and parameters of QT dispersion. Impairment of regional wall motion was evaluated by LV angiogram at baseline and at follow-up. Results: Angiographic follow-up after 5 ± 1.4 months documented reocclusion in eight patients. Complete follow-up with a patent coronary artery and an ECG without bundlebranch block was available in 43 patients. Wall motion severity index (WMSI) improved from � 2.92 ± 0.28 to � 1.34 ± 0.61 (p < 0.001) in patients without Q waves, whereas it was unchanged in patients with Q waves (� 3.01 ± 0.30 and � 2.81 ± 0.32). Absence of Q waves at baseline predicted recovery of regional wall motion with 89% sensitivity and 67% specificity. Positive predictive value for recovery was 68% in patients without Q waves, but only 11% in patients with Q waves. In multivariate analysis, only absence of Q waves predicted improvement in WMSI (p = 0.01). Conclusions:In patients with recanalization of CTO, recovery of regional wall motion is reliably predicted by analysis of the resting 12-lead ECG for pathologic Q waves.

(31)P-MR Spectroscopy for the evaluation of energy metabolism in intact residual myocardium after acute myocardial infarction in humans.

Experimental studies have demonstrated that acute myocardial infarction (MI) alters energy metabolism even in non-infarcted adjacent tissue. In patients with subacute MI, the influence of the regional ischemic insult on energy metabolism of intact septal myocardium was analyzed using 31P-Magnetic resonance spectroscopy (MRS). In eight patients with wall motion abnormalities in the anterior wall 31P-spectra were obtained from non-infarcted adjacent septal myocardium, as well as infarcted anterior myocardium (voxel size 25 ccm each) 29+/-8 days after MI using a 3D-CSI technique. Additionally, cardiac function was analyzed using breath-hold cine MRI. MRI was repeated 6 months after revascularization to assess viability of infarcted segments. Eight age-matched healthy volunteers served as control group. According to follow-up MRI 4/8 patients showed regional wall motion recovery. Here, PCr/ATP-ratios were not significantly reduced in intact septal myocardium as well as infarcted anterior myocardium compared to healthy volunteers (1.28+/-0.10 and 1.14+/-0.09 vs. 1.45+/-0.29). No recovery of regional function was detected in 4/8 patients with-therefore-non-viable anterior myocardium. PCr/ATP-ratios were significantly reduced in intact and infarcted myocardium compared with healthy volunteers as well as to patients with wall motion recovery (0.77+/-0.17 and 0.49+/-0.23; P<0.05). These preliminary results indicate that energy metabolism is reduced in patients with persisting wall motion abnormalities after myocardial infarction and revascularization in ischemically injured as well as in adjacent non-injured myocardium.

Establishing an approach for patients with recent coronary occlusion: Identification of viable myocardium

Background. Revascularization of occluded coronary arteries after myocardial infarction (MI) may restore flow to viable myocardium and improve ventricular function. The aim of this pilot study was to determine the potential utility of thallium-201 viability imaging for the prediction of recovery of regional ventricular function in patients undergoing revascularization of total or subtotal occlusion of infarct-related arteries (TIMI 0–2 flow) during the convalescent period after MI. Methods. Twenty-three patients were identified < 6 weeks after MI and underwent TI-201 viability imaging (rest imaging, n = 16; stress/reinjection imaging, n = 7) and radionuclide angiography. Patients were revascularized with percutaneous transluminal coronary artery in 10, stent in 10, and bypass in 3. Follow-up radionuclide angiography at 3 months was used to assess recovery of regional wall motion. Results. Among 41 abnormal wall motion segments in the infarct territories, the sensitivity, specificity, and accuracy for TI-201 imaging in the prediction of recovery of regional function were 89% ( 25 28 ), 54% ( 7 13 ), and 78% ( 32 41 ), respectively. When 8 segments supplied by vessels with restenosis to >70% were excluded, specificity improved to 70%. Wall motion scores improved in those with adequate revascularization (1.6 ± 1.4 vs 2.7 ± 1.6; P < .001) but not in those with restenosis or occlusion (1.8 ± 1.0 vs 2.0 ± 1.6; P = NS). Conclusions. In patients with an occluded artery after MI, TI-201 viability imaging can detect recoverable myocardium with reasonable accuracy and may help select which patients will most benefit from revascularization.

Prognostic Value of Slow Resolution of ST-Segment Elevation Following Successful Direct Percutaneous Transluminal Coronary Angioplasty for Recovery of Left Ventricular Function

Our objective was to investigate the significance of the slow resolution of ST-segment elevation following a successful direct percutaneous transluminal coronary angioplasty (PTCA). ST-segment elevations were calculated from electrocardiograms recorded before PTCA and 1 hour after reperfusion. Forty-nine patients experiencing their first anterior acute myocardial infarction and who had undergone direct PTCA were classified into 3 groups: 17 patients with rapid ST resolution (group I), 23 patients with persistent ST elevation (group II), and 9 patients with ST reelevation (group III). Left ventricular function was evaluated by using single-plane cineventriculography performed in the acute stage, at discharge, and 4 months later. Peak creatine kinase activity was significantly increased: group III (4,046 ± 634 IU), group II (3,336 ± 772 IU), and group I (2,410 ± 994 IU); p <0.05. Ejection fraction and regional wall motion in the acute stage were identical in each group. However, they were significantly higher in group I (67 ± 6%, −1.01 ± 0.30), followed by group II (56 ± 6%, −1.90 ± 0.41) and group III (38 ± 7%, −2.79 ± 0.46); p <0.01 4 months later. Multiple regression analysis revealed that the ST resolution was the only significant variable that indicated the recovery of regional wall motion. A good linear correlation was documented between the ST resolution and the recovery of regional wall motion. We concluded that a slow ST resolution after successful direct PTCA is a negative predictor of recovery of left ventricular function, especially when ST reelevation is evident.

938-57 Coronary Flow Velocity Immediately After Successful Direct Coronary Angioplasty Predicts Recovery of Regional Wall Motion in Acute Myocardial Infarction

To predict the recovery of left ventricular regional wall motion after successful direct angioplasty in acute myocardial infarction, we measured coronary flow velocity variables using Doppler guidewire (FloWire) immediately after reperfusion in 22 patients (pts) (14LAD, 8RCA) and compared them with left ventriculographic indices. Average peak velocity (cm/sec; mean ± SD) was 17.6 ± 8.0, average diastolic peak velocity (em/sec; mean ± SD) was 21.7 ± 10.6 and diastolic systolic velocity ratio (DSVR) was 2.1 ± 1.0. Patients were divided into 2 groups based on DSVR (normal DSVR: LAD &gt; 1.7, RCA &gt; 1.4). There were no significant differences between 2 groups in peak CPK, elapsed time and collateral flow grade. Left ventricular ejection fraction (EF) and regional wall motion (RWM) by left ventriculogram on admission and at discharge were compared between normal DSVR group (n = 15; 10LAD, 5RCA) and low DSVR group (n = 7; 4LAD, 3RCA). RWM (SD/chord) Normal DSVR (n = 15) Low DSVR (n = 7) p-value on admission -30 ± 0.7 -25 ± 0.5 NS at discharge -2.0 ± 1.0 -2.0 ± 0.6 NS ΔRWM EF(%) 1.0 ± 0.4 0.5 ± 0.4 &lt; 0.05 on admission 48 ± 13 53 ± 6 NS at discharge 62 ± 11 52 ± 10 NS ΔEF 14 ± 6 -1 ± 9 &lt; 0.05 Measurements of coronary flow velocity immediately after direct coronary angioplasty predict the recovery of regional and global left ventricular function in pts with acute myocardial infarction

752-5 Dose the “No Reflow” Phenomenon Immediately After Successful Direct Angioplasty Always Indicate Poor Functional Recovery?

Experimental studies have demonstrated that “no reflow” phenomenon after prolonged coronary occlusion indicates advanced myocardial necrosis. In clinical settings, previous studies have suggested that presence of “no reflow” phenomenon following thrombolysis is a useful predictor of poor functional recovery. To test the hypothesis that “no reflow” phenomenon is closely related to the recovery of regional wall motion in a reperfused AMI, we studied 42 myocardial segments in 18 patients with AMI who achieved successful direct angioplasty. MCE was performed immediately after direct angioplasty and repeated 2 weeks later with intracoronary injection of sonicated albumin. Contrast effect in each segment was scored as 0–2 (0, 1 and 2 denoting no, partial and homogeneous contrast effect, respectively). 2D-Echo was performed at day-1 and repeated 1 month later. Wall motion (WM) by 2D-Echo was scored as 0–3 (scores of 0 to 3 indicating dys/akinetic segments to normal. respectively). The relation between mean WM and MCE score immediately after direct angioplasty was as follows: MCE score day-l WM 1 Month WM Change 2 (n = 20) 1.1 ± 0.8 ** 1.7 ± 0.7 * , # 0.6 ± 0.9 1 (n = 7) 0.6 ± 0.8 * 1.4 ± 1.4 # 0.9 ± 0.9 0 (n = 15) 0.0 ± 0.0 0.8 ± 1.0 ## 0.8 ± 1.0 * p &lt; 0.01 ** p &lt; 0.001 vs. MCE score = 0 # p &lt; 0.05 ## p &lt; 0.01 vs. day-l WM Seven of 15 segments (47%) with MCE score = 0 immediately after direct angioplasty showed functional recovery at 1 month later, and 6 of the 7 segments (86%) showed contrast enhancement at 2 weeks later restudy. About one half of segments which showed no contrast enhancement immediately after direct angioplasty showed functional recovery at 1 month later, and the majority of these segments showed contrast enhancement at 2 weeks later restudy. The “no reflow” phenomenon by MCE immediately after successful direct angioplasty dose not always indicate poor functional recovery.

USEFULNESS OF DETERMINING REGIONAL MYOCARDIAL GLUCOSE METABOLISM BY FDG-PET FOR EVALUATION OF MYOCARDIAL VIABILITY EARLY AFTER REPERFUSION

The outcome of acute myocardial infarction has been significantly changed by the introduction of invasive coronary reperfusion procedures. However, the myocardial saving effect of reperfusion is difficult to evaluate in the early phase because of the presence of stunned myocardium. Is it possible to predict the future recovery of regional wall motion early after reperfusion? We assessed regional myocardial glucose metabolism in relation to the late effect of reperfusion. In a dog reperfusion model, there was a good linear correlation between the regional myocardial metabolic rate of glucose (MMRG) determined 12 hours after the termination of reperfusion using 18-F fluorodeoxyglucose (FDG) and positron emission tomography and the amount of surviving myocardium (r=0.86, p<0.01). The MMRG was normal or increased in the area where regional contraction was regained 4 weeks after reperfusion, but was decreased in the area which remained akinetic or dyskinetic in the late phase. When the normal lower limit was set as the mean minus 2 standard deviations in the control group, normal MMRG indicated viable myocardium and later functional recovery, while lower MMRG suggested permanent functional loss. Thus, myocardial viability seems to be appropriately evaluated by the determination of MMRG.

Recovery of myocardial function. The ultimate target of coronary revascularization.

Recovery of myocardial contraction represents an important target of coronary revascularization and the preoperative recognition of viable akinetic (hibernating) myocardium is a crucial point of the preoperative investigation of patients with chronically depressed left ventricular function. In 14 patients dobutamine infusion during echocardiography was utilized to evoke the contractile reserve retained by viable akinetic segments. Redistribution of thallium(TI)-201 after the rest injection was also used to assess the viability of akinetic areas. The wall motion response to dobutamine infusion predicted immediate postoperative improvement in 85 of 93 segments (sensitivity 91.3%) and identified 25 of the 32 segments which did not exhibit early postoperative improvement (specificity 78.1%). Rest redistribution of TI-201 demonstrated high sensitivity (93.0%) but low specificity (43.7%) for predicting the early recovery of regional wall motion. When late recovery was also considered, the specificity of this method increased to 64.0%. Rest distribution of TI-201 identifies viability which is not necessarily associated with the early recovery of function postoperatively. When the echo-dobutamine test is positive, on the other hand, the recovery of function usually occurs immediately after revascularization and the operative risk is expected to be low even in the presence of severely compromised left ventricular function.

Superiority of controlled surgical reperfusion versus percutaneous transluminal coronary angioplasty in acute coronary occlusion

Although percutaneous transluminal coronary angioplasty is successful in more than 90% of patients after acute coronary occlusion, overall mortality remains approximately 10% with higher subgroup mortality (i.e., occlusion of the left anterior descending coronary artery, multivessel disease, age older than 70 years, cardiogenic shock) and early recovery of regional wall motion is marginal. This multicenter report shows that controlled surgical reperfusion in patients with acute coronary occlusion reduces overall and subgroup mortality and restores substantial early contractility. In a survey from six institutions, 156 consecutive patients with acute coronary occlusion documented by angiography underwent surgical revascularization with controlled reperfusion using amino acid-enriched blood cardioplegic solution on total vented bypass. Ventricular wall motion was studied by echocardiography or multiple gated acquisition scan on postoperative days 5 to 7 and scored independently (0 = normal, 1 = mild hypokinesia, 2 = severe hypokinesia, 3 = akinesia, 4 = dyskinesia). Results are compared with results in 1203 patients with acute coronary occlusion treated by angioplasty in five reported medical series. Surgically treated patients were revascularized at longer ischemic intervals (6.3 versus 3.9 hours, p < 0.05) and had a greater incidence of left anterior descending occlusion (61% versus 43%, p < 0.05), multivessel disease (42% versus 22%, p < 0.05), and cardiogenic shock (41% versus 10%, p < 0.05), with 12 patients undergoing cardiopulmonary resuscitation en route to the operating room. Surgical results were superior in all categories, with overall mortality reduced from 8.7% after angioplasty to 3.9% after coronary bypass (p < 0.05). All surgical deaths occurred in patients with preoperative cardiogenic shock. Regional wall motion recovered significantly (score < 2) in 131 of 150 (87%) surgically treated patients with an average score of 0.9 +/- 0.8 (normal to mild hypokinesia) despite longer ischemic times.

Effect of buckberg cardioplegia and peripheral cardiopulmonary bypass on infarct size in the closed chest dog

Objectives. To simulate a human catheterization laboratory setting of controlled reperfusion during myocardial infarction, regional infusion of commercially available Buckberg cardioplegic solution and peripheral vented bypass were administered in the closed chest dog.Background. Studies in open-chest dogs have demonstrated a significant reduction in infarct size and improvement in regional wall motion with a similar controlled reperfusion method using infusion of substrate-enriched (Buckberg) cardioplegic solution during cardiopulmonary bypass coupled with left ventricular venting.Methods. After 100 or 180 min of balloon occlusion of the proximal left anterior descending artery, controlled reperfusion was performed with cardioplegic infusion and vented bypass. Dogs matched for occlusion time underwent balloon deflation without bypass or cardioplegia (uncontrolled reperfusion groups). Microspheres were used to quantify coronary ischemia during balloon inflation. All four groups (n = 8 to 9 per group) were followed up at 1 week to determine regional wall motion and infarct size.Results. Qualitative echocardiographic analysis demonstrated no significant difference among groups in recovery of regional wall motion at 1 week; however, wall motion improved significantly in all groups between the ischemia and 1-week recovery periods. The histologic infarct size compared with the area at risk for dogs with uncontrolled versus controlled reperfusion, respectively, was 17.9 ± 10.5% versus 31.9 ± 8.3% (p < 0.05) for dogs with 100 min of occlusion and 40.1 ± 11.7% versus 46.2 ± 8.4% (p = NS) for dogs with 180 min of occlusion. A greater rate-pressure product in the dogs with controlled reperfusion after 100 min of occlusion (p < 0.05) may explain the larger infarct size observed for that group.Conclusions. These results demonstrate that regional infusion of substrate-enriched cardioplegic solution in combination with peripheral vented bypass does not further reduce infarct size after prolonged ischemia in the closed chest dog (compared with uncontrolled reperfusion).