Improvement In Wall Motion Score Research Articles

4936Cardiac magnetic resonance strain analysis predicts functional recovery following acute ST-segment elevation myocardial infarction

Abstract Background Late gadolinium enhancement (LGE) is the clinical reference standard for estimation of infarct extension and prediction of functional recovery following reperfused acute ST-segment elevation myocardial infarction (STEMI). Nevertheless, myocardial edema, microvascular obstruction and intramyocardial hemorrhage as well as the timing of image acquisition after contrast administration may influence the extent of LGE and underestimate the potential for recovery. Dobutamine stress testing has been recommended to more accurately predict functional recovery when infarct transmurality is between 25 to 75%. We hypothesized that cardiac magnetic resonance (CMR) tissue tracking strain analysis may provide additional value to LGE for the prediction of functional recovery. Methods In 370 patients with STEMI who underwent successful primary percutaneous revascularization and were studied with CMR within 3–5 days of the event, peak systolic longitudinal (LS), circumferential (CS) and radial (RS) strain were analyzed with routine SSFP images of 3 long-axis and a stack of short-axis slices (Tissue Tracking, CVI42®, Figure panel A and B). Inversion-recovery echogradient sequences were analyzed 20 minutes after contrast administration for LGE transmurality (Panel C). All per-segment analysis was performed according to the AHA 16-segment model. CMR was repeated at 6 months and functional recovery was defined as persistent normokinesia or improvement of wall motion score from baseline to 6-month CMR. Results At baseline CMR, of a total of 5920 segments 70.4% were normokinetic, 7.2% were hypokinetic, 21.9% were akinetic and 0.6% were dyskinetic. All strain parameters decreased significantly with worsening wall motion. At follow-up, 81.5% of the segments showed functional recovery. All strain parameters were significantly associated with functional recovery (p<0.001) and showed higher predictive value for improvement of wall motion than LGE transmurality (ROC AUC 0.713 LS, 0.710 CS, 0.683 RS and 0.660 LGE). For basal CMR dysfunctional segments, a CS <−10.7% showed the highest accuracy (66%) to predict wall motion improvement, with 58% sensitivity, 76% specificity, 75% positive predictive value (PPV) and 59% negative predictive value (NPV). These results were comparable to LGE transmurality <50% (65% accuracy, 59% sensitivity, 73% specificity, 74% positive predictive value and 58% negative predictive value). Nevertheless, adding CS analysis to a 50% LGE transmurality cutoff was the best combination for prediction of functional recovery and increased the overall accuracy to 70%, with 76% sensitivity, 64% specificity, 65% PPV and 75% NPV. CS analysis in an inferior STEMI Conclusions Acute CMR tissue tracking strain analysis complements LGE assessment for prediction of functional recovery following an STEMI. The combination of LGE infarct transmurality under 50% and a CS strain higher than −10.7% showed the highest accuracy for prediction of recovery of function.

UTILITY OF NON-INVASIVE CORONARY FLOW PATTERN VERSUS FRACTIONAL FLOW PRESSURE DROP FOR LEFT ANTERIOR CORONARY ARTERY STENTING

Background and Aim: To assess the usefulness of coronary flow reserve as a guide in patient with left anterior descending coronary artery lesion during percutaneous coronary intervention in comparison with fractional flow reserve. Methods: The study included 80 patients with left anterior descending artery stenotic lesions, proved by coronary angiography, in the cardiac catheterization laboratory of the Faculty of Military Hospital, during the period from November 2012 to June 2014. All patients were subjected to all of the following: Complete history taking, full general and local examination, ECG analysis. All our patient were assessed by Doppler wire to measure pressure drop at LAD lesion and also by non-invasive coronary flow pattern utilizing transthoracic echo-Doppler study. Then we compare the results of both values on the basis of the improvement in left ventricular ejection fraction( by biplane Simpson rule) to find the cut point at which we can document that this LAD lesion deserve stenting . Results: FFR was negatively correlated with significant correlation with EF improvement with R value of -0.575 and P-value of 0.008,figure. Also there is strong inversed relation with lesion percent with R-value of-0.468 and P-value of 0.01. The correlation between FFR and improvement in wall motion score was significantly inversed with R-value of -0.519 and P-value of 0.03. Also there was strong correlation between FFR and CFR ,P-value was 0.00 and R-value was+0.436. CFR has strong reciprocal correlation with FFR (P-value was 0.00 and R-value was. inve+0.436. There is significant correlation of CFR with EF improvement with R value of -0.583and P-value of 0.002. Also there is significant correlation of CFR with lesion percent with R-value of -0.585and P-value of 0.001, figure. The correlation between CFR and wall motion score was significant with R-value of-0.393 and P-value of 0.03. The optimal cutoff values for coronary flow reserve of <1.75 was the best value for indication of stenting of an intermediate coronary lesion. A sensitivity of 92% and a specificity of 87%. On the other hand the best cut-of value of fractional flow reserve was <0.75 for indication of stenting for an intermediate coronary artery lesion with a sensitivity of 94% and specificity of 86%. Conclusions: The current study showed Coronary flow reserve measurements by TTE in the distal to mid LAD were feasible in most patients with an optimal cut-off value < 1.75 showed high accuracy to detect angiographically significant stenoses in the LAD. This is comparable to <0.75 as an optimal cut-off value of FFR to detect angiographically significant stenoses. CFR measurement utilizing TTE might be considered as a simple non-invasive tool for functional status of an intermediate coronary artery lesion for stenting. Key Words: LAD (left anterior descending artery ), coronary flow reserve, fractional flow reserve.

Prediction of global and segmental functional changes after acute myocardial infarction by 2D speckle-tracking echocardiography and cardiac magnetic resonance imaging

Purpose: Myocardial deformation analysis by 2-dimensional (2D) speckle-tracking echocardiography (STE) has been shown to accurately predict viability in patients with chronic ischemic LV dysfunction. This study evaluated STE for prediction of global and segmental left ventricular (LV) functional changes after acute myocardial infarction (AMI) in comparison with late gadolinium enhancement cardiac magnetic resonance (LGE). Methods: In 93 patients (60±11 years) with first AMI (55 with ST-segment elevation myocardial infarction (STEMI) and 38 with Non-ST-segment elevation myocardial infarction (NSTEMI)), all treated by acute percutaneous coronary intervention peak global longitudinal strain was determined to describe global function by STE and peak systolic circumferential strain was determined for segmental function analysis. LGE was performed to define the amount of global and segmental myocardial scar. STE and LGE were performed within 48 hours after AMI. At 6 months follow-up transthoracic echocardiography was repeated to determine global (increase of ejection fraction ≥5%) and segmental (improvement of wall motion score at least one grade) LV recovery as well as global LV remodeling (increase of end-systolic volume >15%). Results: Accuracy to predict global functional improvement and LV remodeling at 6 months follow-up after AMI was similar for STE vs. LGE (AUC=0.715 vs. AUC=0.729, p=0.8830 and AUC=0.806 vs. AUC=0.824; p=0.7141, respectively). In patients with STEMI accuracy of circumferential strain analysis by STE to predict segmental functional improvement was non-inferior compared to analysis of LGE (AUC=0.679 vs. AUC=0.755; p=0.0512), while in patients with NSTEMI accuracy of strain analysis by STE for prediction of segmental functional improvement was lower compared to LGE (AUC=0.666 vs. AUC=0.838; p=0.0004). Conclusions: In patients with AMI, accuracy to predict global functional recovery as well as LV remodeling by 2D STE is comparable to LGE. In patients with STEMI, myocardial deformation analysis by 2D STE allows prediction of segmental functional recovery with non-inferior accuracy compared to LGE, while accuracy to predict segmental functional improvement is less in patients with NSTEMI.

ST segment elevation during dobutamine stress echocardiography after acute myocardial infarction: Clinical significance and correlation with contractile recovery

The aim of this study was the evaluation of the value of dobutamine stress induced ST-segment elevation after acute myocardial infarction in predicting spontaneous contractile recovery. Fifty eight consecutive patients were studied within 7 days after first acute myocardial infarction (AMI) with dobutamine stress echocardiography (DSE). A score model based on 16 segments and four grades was used to assess the left ventricular function and a twelve-lead electrocardiography was continuously monitored throughout the test. Follow up was performed by trans-thoracic echocardiography at 90 days. At follow up, contractile recovery was defined as improvement of wall motion score by more than one grade in at least two myocardial segments. ST-segment elevation was observed in 24 (41%) out of the 58 patients studied. During DSE; persistent segmental wall motion abnormalities were more frequently observed in patients without ST-segment elevation while improvement without subsequent worsening was more frequently observed in patients with ST-segment elevation ( P = 0.001). On follow up, contractile recovery was reported in 37 (64%) patients, it was more frequently observed in patients who already developed ST-segment elevation during DSE ( P = 0.007). Dobutamine induced ST-Segment elevation has the sensitivity, specificity, positive and negative predictive values of 66%, 86%, 88% and 53%, respectively to predict spontaneous contractile recovery after AMI, while the combined sensitivity, specificity, positive and negative predictive values of dobutamine echocardiography and electrocardiography were 73%, 89%, 94% and 64%, respectively. Dobutamine stress induced ST segment elevation occurring in electrocardiographic leads exploring an infarct area is a predictor of spontaneous contractile recovery after AMI particularly when combined with echocardiogarphic evidence of myocardial viability.

Deterioration of Regional Wall Motion Immediately after Coronary Artery Bypass Graft Surgery Is Associated with Long-term Major Adverse Cardiac Events

Patients undergoing coronary artery bypass graft (CABG) surgery frequently develop wall motion abnormalities diagnosed by intraoperative transesophageal echocardiography. However, the relation between deterioration in wall motion and postoperative morbidity or mortality is unclear. Therefore, the authors hypothesized that deterioration in intraoperative left ventricular regional wall motion immediately after CABG surgery is associated with a higher risk of adverse cardiac events. With institutional review board approval, data were gathered from 1,412 CABG surgery patients. Echocardiographic wall motion score (WMS) was derived using a 16-segment model. Outcomes data were gathered for up to 2 yr after surgery. The primary outcome, major adverse cardiac event, was a composite index of myocardial infarction, need for subsequent coronary revascularization, or all-cause mortality during the follow-up period. Two hundred twenty-one patients (16%) had 254 primary outcome events during follow-up. Postbypass WMS did not change in 812 patients (58%), deteriorated in 219 patients (16%), and improved in 368 patients (26%). Kaplan-Meier analysis showed that patients with deterioration in WMS after CABG experienced significantly lower major adverse cardiac event-free survival than patients with either no change or improvement in WMS (P = 0.004). Cox proportional hazards regression modeling revealed a significant association between deterioration in WMS and the composite adverse outcome (hazard ratio, 1.47 [1.06-2.03]; P = 0.02). The authors confirmed their hypothesis that deterioration in wall motion detected by intraoperative echocardiography after CABG surgery is associated with increased risk of long-term adverse cardiac morbidity. Worsening wall motion after CABG surgery should be considered a prognostic indicator of adverse cardiovascular outcome.

Dobutamine stress echocardiography can predict reversible ventricular dysfunction after acute myocardial infarction

The aim of early treatment of acute myocardial infarction (AMI) is to achieve the rapid reperfusion of the culprit artery, which correlates with improvement in ventricular function and survival. With the widespread use of thrombolytic agents or coronary angioplasty as reperfusion strategies for AMI, it is possible to reduce the amount of myocardial necrosis. The assessment of residual viability with dobutamine stress echocardiography (DSE) in the infarcted area after AMI is relevant to subsequent management and prognosis. Thirty-seven patients with AMI (mean age 59 +/- 12, 31 male, 22 with anterior AMI, 15 with inferior AMI) admitted to the coronary care unit within 3.8 +/- 1.8 h of the onset of symptoms were included. Two-dimensional echocardiography (2-D echo) study and DSE were performed at a mean of 4.7 +/- 1.8 days. Follow-up 2-D echo was performed at a mean of 25 +/- 11 days. To assess left ventricular regional systolic function, 2-D echo images were obtained at rest and during dobutamine-induced stress and were analyzed off-line according to the 13-segment model. Improvement in wall motion score (WMS) was defined by a decrease of at least two grades in the score. Wall motion score improved in 13 of the 37 patients after DSE (rest WMS 20.9 +/- 2.0 vs. D-WMS 17.7 +/- 2.2; p<0.001), which correlated with clinical or angiographic signs of reperfusion of the culprit vessel in all cases. Follow-up WMS evidenced a significant correlation with WMS after DSE (r = 0.91; p < 0.001). Sensitivity, specificity, and positive and negative predictive values of DSE in detecting patients whose left ventricular function (LVF) improved at 2-D echo follow-up were 72,96,92.8, and 82.7%, respectively. (1) Dobutamine stress echocardiography improved WMS in 35% of patients and correlated with signs of patency of the culprit vessel; (2) LVF improvement after dobutamine was predictive of late LVF recovery; (3) DSE can be a useful and safe tool for detecting reversible myocardial dysfunction after AMI.

Early changes in myocardial perfusion patterns after myocardial infarction: relation with contractile reserve and functional recovery.

The purpose of this study was to assess early temporal changes in myocardial perfusion pattern by myocardial contrast echocardiography (MCE) and their relation to myocardial viability in patients with reperfused acute myocardial infarction (AMI). Myocardial contrast echocardiography no-reflow is associated with poor contractile recovery after AMI. However, little is known regarding early reversibility of microvascular dysfunction and its relation to myocardial viability. Intracoronary MCE was performed immediately after reflow and 9 days later in 28 patients with a first AMI and successful coronary recanalization (Thrombolysis in Myocardial Infarction trial grade 3 flow). Semiquantitative contrast score and wall motion score (WMS) were assessed in each initially asynergic segment at initial and repeat MCE study. Low dose dobutamine echocardiography (DE) was performed at day 10, and follow-up (FU) rest echocardiography was performed 6 weeks later. Among 200 initially asynergic segments, 49% exhibited no or heterogeneous contrast enhancement at initial MCE versus 24% at restudy (p < 0.001). Three groups of segments were defined according to early changes in contrast pattern: group A, "sustained no-reflow" (n = 17); group B, improved contrast score (n = 68), and group C, "sustained reflow" (n = 112). Group A segments showed no improvement in WMS at FU. In contrast, group B segments showed significant improvement in WMS at FU (p < 0.0001), and exhibited more frequently contractile reserve at DE (36% vs. 6%, p = 0.02) and contractile recovery at FU (34% vs. 7%, p = 0.03) than group A segments. Group C segments exhibited contractile reserve and contractile recovery in 47% and 51% of segments respectively. Improvement in MCE perfusion pattern may occur after initial no-reflow in the days following reperfused AMI and is associated with preservation of contractile reserve and gradual regional functional recovery.

Relation of Ultrasonic Tissue Characterization With Integrated Backscatter to Contractile Reserve in Chronic Left Ventricular Ischemic Dysfunction

Previous studies have shown that viable but stunned myocardium displays contractile reserve and exhibits cardiac cycle-dependent variations of integrated backscatter, whereas infarcted myocardium does not. The present study was designed to evaluate whether integrated backscatter imaging could be useful in identifying segments with recruitable inotropic reserve in patients with chronic left ventricular (LV) ischemic dysfunction. We studied 15 patients (mean age 59 ± 10 years) with chronic coronary artery disease, anterior or inferior wall dysfunction, and depressed LV ejection fraction (35 ± 12%), and 6 noncardiac control subjects (mean age 49 ± 18 years). Cardiac cycle-dependent variations of integrated backscatter were measured in anterior and inferior segments during transesophageal echocardiography and compared with the contractile response (% wall thickening) of these segments to low doses of dobutamine (5 to 10 μg/kg/min). The average magnitude of cardiac cycle-dependent variations of integrated backscatter was greater among normally contracting segments of both patients and controls (5.67 ± 0.88 and 5.64 ± 2.26 dB, respectively, p = NS) than among dysfunctional segments (2.77 ± 3.05 dB, p <0.01 vs control and remote segments). Dysfunctional segments were further categorized into those with and without dobutamine-induced contractile reserve. At baseline, systolic wall thickening was similar among segments responding to dobutamine than among those that did not (3.6 ± 2.3% vs 2.9 ± 1.6%, p = NS). During dobutamine, systolic wall thickening increased only in segments showing improvement in wall motion score (to 24.5 ± 4.7%), whereas it remained unchanged in segments not responding to dobutamine (to 2.0 ± 3.7%, p <0.01). The magnitude of resting cardiac cycle-dependent variations of integrated backscatter was larger in segments responding to dobutamine than in those with persistent dysfunction (5.31 ± 2.06 vs 0.23 ± 0.94 dB, p <0.01) and correlated significantly (r = 0.74, p <0.01) with systolic wall thickening during dobutamine. Our data demonstrate that resting cardiac cycle-dependent variations of integrated backscatter closely parallel contractile reserve in patients with chronic LV ischemic dysfunction. This suggests that tissue characterization with integrated backscatter could be a useful adjunct to the delineation of myocardial viability in these patients.

Relationship between progressive microvascular damage and intramyocardial hemorrhage in patients with reperfused anterior myocardial infarction: myocardial contrast echocardiographic study.

Recent studies indicated that ischemic microvascular damage may be reversible or progressive after coronary reflow. Intramyocardial hemorrhage is a phenomenon that reflects severe microvascular injury. We examined the relationship between temporal changes in microvascular perfusion patterns detected by myocardial contrast echocardiography (MCE) and intramyocardial hemorrhage detected by magnetic resonance imaging (MRI) in patients with acute myocardial infarction (AMI). The study population consisted of 24 patients with anterior AMI. All patients underwent MCE shortly after reflow and in the chronic stage (a mean of 31 days after reflow). Wall motion score (WMS) was determined as the sum of 16 segmental scores (dyskinetic/akinetic=3 to normal=0) at days 1 and 31. Gradient-echo acquisition and gadolinium-DTPA-enhanced spin-echo MRI were performed within 10 days after reflow. In MCE shortly after reflow, 16 patients (67%) showed contrast enhancement and the other 8 patients (33%) showed a sizable contrast defect. In the chronic stage, a persistent contrast defect was observed in 7 of 8 patients with a contrast defect shortly after reflow. Consistent contrast enhancement was observed in 12 of 16 patients (75%) with contrast enhancement shortly after reflow, indicating that a contrast defect newly appeared in 4 patients (25%). Intramyocardial hemorrhage was detected in 9 patients (38%): 5 of 7 patients with a persistent contrast defect and in all 4 patients with a new appearance of a contrast defect during the chronic stage. The patients without hemorrhage showed a significant improvement in WMS compared with patients with hemorrhage at day 31 (5+/-5 versus 19+/-6, P<.0005). These results suggest that irreversible microvascular damage to the ischemic myocardium may cause intramyocardial hemorrhage after reflow, associated with impaired recovery of left ventricular function. Contrast enhancement within the risk area shortly after reflow does not necessarily indicate long-term microvascular salvage.

Relation of contractile reserve during low-dose dobutamine echocardiography and angiographic extent and severity of coronary artery disease in the presence of left ventricular dysfunction

Contractile reserve, during low-dose dobutamine echocardiography, is frequently used for the assessment of myocardial viability in patients with coronary artery disease (CAD) and left ventricular (LV) dysfunction. Whether contractile reserve is affected by the severity of the underlying, CAD is presently unknown. Accordingly, we studied 58 patients with stable CAD and LV dysfunction who underwent coronary angiography and low-dose dobutamine echocardiography. In each vascular region the worst stenosis was identified and quantitated as percent diameter stenosis. Segmental wall motion during echocardiography was scored visually and rest and dobutamine wall motion score indexes were calculated. Contractile reserve was defined as ≥1 grade improvement in wall motion score of ≥2 contiguous segments along with ≥20% reduction in global wall motion score index with dobutamine. There was no difference between patients with (n = 26) and without (n = 32) contractile reserve in percent coronary stenosis (89 ± 17% vs 87 ± 17%, p = 0.6), number of coronary arteries with >50% diameter stenosis (2.0 ± 0.8 vs 2.2 ± 0.7, p = 0.4), number of occluded coronary arteries (1.2 ± 0.9 vs 1.1 ± 0.9, p = 0.6), or the prevalence of collaterals demonstrated angiographically (61% vs 56%, p = 0.5). Our data demonstrates that in patients with CAD and LV dysfunction, the prevalence of contractile reserve during low-dose dobutamine echocardiography is independent of the angiographic extent and severity of CAD.

Resolution of late potentials with improvement in left ventricular systolic function in patients with first acute myocardial infarction.

Ventricular late potentials predict subsequent arrhythmic events and sudden death in postinfarction patients. Late potentials are recorded in the infarcted area, but it should be pointed out that they probably represent micropotentials in the area of delayed conduction found among isolated areas of scar tissue and normal myocardium. The study was undertaken to investigate the relationship between chronic reversible myocardial ischemia, such as stunned or hibernating myocardium, and late potentials in 38 patients with a first myocardial infarction. The patients were divided into two groups, one with (Group 1) and one without (Group 2) resolution of late potentials recorded by signal-averaged electrocardiogram at 6 months after onset of myocardial infarction. We investigated the clinical, echocardiographic, and signal-averaged electrocardiographic characteristics of Groups 1 and 2. In the chronic phase of myocardial infarction, a higher incidence of patency of the infarct-related artery and an improvement of wall motion score were found in Group 1, and left ventricular ejection fraction was better preserved in Group 1 than in Group 2. These results suggest that the resolution of late potentials was influenced by the improvement of left ventricular systolic function and patency of the infarct-related artery. We concluded that chronic reversible myocardial ischemia, such as stunned or hibernating myocardium, might be the substrate that generated late potentials.

Accuracy of dobutamine echocardiography for detection of myocardial viability in patients with an occluded left anterior descending coronary artery

We studied the accuracy of dobutamine echocardiography for the detection of myocardial viability in patients with an occluded left anterior descending coronary artery and regional ventricular dysfunction. Contractile reserve during dobutamine echocardiography is an accurate marker of myocardial viability in patients with coronary stenoses and ventricular dysfunction. However, its accuracy in patients with an occluded vessel has not been evaluated. We studied 41 patients with > 50% stenosis of the left anterior descending coronary artery and regional ventricular dysfunction who underwent dobutamine echocardiography for detection of viable myocardium. Contractile reserve was defined as improvement in wall motion score of two or more contiguous septal or anterior segments during doubutamine echocardiography. Recovery of function was defined as improvement in rest wall motion score of two or more contiguous segments after revascularization. Patients were classified into two groups according to the presence (n = 20) or absence (n = 21) of left anterior descending coronary artery occlusion. Contractile reserve was detected in 40% of patients with an occluded and 43% with a nonoccluded artery (p = 0.8). Of 41 patients, 27 underwent revascularization, 12 with and 15 without an occluded vessel. Recovery of function occurred in 6 (50%) of 12 patients in the occluded artery group and in 5 (33%) of 15 in the nonoccluded artery group (p = 0.4). Among patients with an occluded artery, the positive and negative predictive values of dobutamine echocardiography for recovery of function were 100% (95% confidence interval [CI] 48% to 100%) and 86% (95% CI 42% to 100%), respectively. Our results indicate that contractile reserve during dobutamine echocardiography can be detected in patients with an occluded vessel and may be useful for predicting recovery of function after revascularization.

Head-to-head comparison of exercise-redistribution-reinjection thallium single-photon emission computed tomography and low dose dobutamine echocardiography for prediction of reversibility of chronic left ventricular ischemic dysfunction

We sought to directly compare the diagnostic value of exercise-redistribution-reinjection thallium single-photon emission computed tomography (SPECT) and low dose dobutamine echocardiography for prediction of contractile recovery after revascularization. Both thallium SPECT and dobutamine echocardiography have been proposed to predict the reversibility of left ventricular dysfunction after revascularization. Although both techniques permit differentiation of viable from nonviable myocardium, few studies have directly compared their accuracy in the same patients. Seventy-three consecutive patients (mean [+/- SD] age 59 +/- 9 years) with coronary disease and regional left ventricular dysfunction underwent exercise-redistribution-reinjection thallium SPECT and dobutamine echocardiography before revascularization. Recovery of function was evaluated with echocardiography 5.5 +/- 2.5 months after revascularization. For analysis, the left ventricle was divided into 16 segments, in which percent thallium uptake was quantitated using circumferential profiles, and regional wall motion was graded semiquantitatively (normal = 1; akinetic = 3). The diagnostic performance of the two tests was investigated both for individual patients and for individual segments. Individual patient analysis showed that left ventricular ejection fraction improved > 5% after revascularization in 43 patients, whereas 30 showed no change. Receiver operating characteristic curves were used to select optimal criteria for prediction of functional recovery after revascularization. According to a mean thallium uptake > 54% at reinjection, SPECT had a sensitivity of 72%, a specificity of 73% and an overall accuracy of 73%. Similarly, according to an improvement in wall motion score > 3.5 grades during doubutamine echocardiography, echocardiography had a sensitivity of 88%, a specificity of 77% and an overall accuracy of 84% (p = NS vs. thallium). Segmental analysis showed that SPECT and dobutamine echocardiography had similar sensitivity (77% and 75%, respectively), but SPECT had lower specificity (56% vs. 86%, p < 0.01). Quantitative exercise-redistribution-reinjection thallium SPECT and dobutamine echocardiography have comparable accuracy for prediction of reversibility of global left ventricular dysfunction after revascularization. However, dobutamine echocardiography has greater specificity than thallium imaging for prediction of functional recovery on a segmental basis.

Recovery of impaired left ventricular function in patients with acute myocardial infarction is predicted by the discordance in defect size on 123I-BMIPP and 201Tl SPET images.

A discrepancy between myocardial perfusion defect and wall motion abnormalities is frequently found early after coronary reperfusion in patients with acute myocardial infarction. The purpose of this study was to assess recovery of impaired left ventricular function by reference to the discordance in defect size between myocardial fatty acid uptake and myocardial perfusion using combined single-photon emission tomographic (SPET) imaging early after coronary perfusion therapy. In 37 patients with acute myocardial infarction, iodine-123 15-(p-iodophenyl)-3(R, S)-methylpentadecanoic acid (BMIPP) and thallium-201 SPET scans were performed early after coronary reperfusion. A severity score was determined from the extent of the imaging defect with each tracer. Left ventricular wall motion score (WMS) and ejection fraction (EF) were obtained at admission and at 4 weeks after the onset of infarction. In 32 of the 37 patients, discordance in defect sizes delineated with the two SPET studies was found during the acute stage. The severity score for BMIPP was larger than that for 201Tl during the acute stage (7. 7+/-2.4 vs 4.4+/-2.5, P <0.001). There was a fair correlation between the severity score for BMIPP and WMS (r=0.82, P <0.0001), but a poor correlation between that for 201Tl and WMS. The extent of discordance in severity scores between BMIPP and 201Tl during the acute stage correlated well with the extent of the improvement in WMS (r=0.86, P <0.0001) and that of EF (r=0.85, P <0.0001). We conclude that the discordance in defect size on BMIPP and 201Tl SPET images during the acute stage of infarction is an early predictor of the viability of the myocardium at risk of infarction.

Preoperative Selection of Patients With Severely Impaired Left Ventricular Function for Coronary Revascularization

Both thallium imaging and low-dose dobutamine echocardiography have been proposed to predict the reversibility of left ventricular (LV) dysfunction in patients with coronary disease. The present study was designed to evaluate whether the use of these techniques during the preoperative assessment of coronary patients with depressed LV function can improve our ability to identify those likely to have improved LV function after surgery. Forty consecutive patients (age, 60 +/- 10 years) with coronary disease and an ejection fraction < or = 35% underwent dobutamine echocardiography (10 micrograms/kg per minute) and exercise-redistribution-reinjection thallium single photon emission computed tomography (SPECT) before coronary revascularization by bypass surgery (n = 33) or angioplasty (n = 7). Recovery of LV function was evaluated by echocardiography 5.3 +/- 2.4 months after revascularization. According to the changes in end-systolic volume and ejection fraction after revascularization, the patients were categorized into groups with (n = 19) and without (n = 21) postoperative functional improvement, defined as a > 5% increase in ejection fraction and > 10 mL decrease in end-systolic volume. Before revascularization, patients with improved postoperative function had smaller end-diastolic volume and less wall motion abnormalities than those with persistent dysfunction. They also showed greater improvement of wall motion score with dobutamine (6.1 +/- 2.4 versus 1.8 +/- 4.2 grades, P < .001) and smaller thallium defect score after exercise (38 +/- 12 versus 47 +/- 14 grades, P = .04). Discriminant analysis selected the improvement in wall motion score with dobutamine and baseline end-diastolic volume as independent predictors of postoperative recovery. Consideration of both parameters allowed prediction of functional outcome in 84% of the patients with and 81% of those without postoperative improvement. Among the parameters commonly available before surgery in coronary patients with depressed LV function, the maintenance of significant inotropic reserve, the severity of LV remodeling, and the magnitude of the perfusion defect after exercise can predict the reversal of LV dysfunction after revascularization.