Incidence, predictors, and subsequent mortality risk of recurrent myocardial infarction in patients following discharge for acute myocardial infarction.

BACKGROUND: In the percutaneous coronary intervention (PCI) era, little evidence exists regarding the incidence, predictors and long-term mortality of recurrent myocardial infarction (Re-MI) following discharge for acute myocardial infarction (AMI). METHODS AND RESULTS: A total of 7,870 patients who survived AMI were studied with a median follow-up period of 3.9 years: 353 patients (4.5%) experienced Re-MI, with 7 of those dying within 30 days, which was classified as fatal Re-MI. The incidence of Re-MI per year was 2.65% for the first year, and 0.91-1.42% thereafter up to 5 years. Multivariate Cox regression analyses revealed that predictors of Re-MI were diabetes mellitus (hazard ratio (HR): 2.079, P<0.001), history of MI (HR: 1.767, P=0.001), and advanced age (HR: 1.021, P=0.001). These 3 predictors remained significant when angiographic and procedural parameters were incorporated into the analyses. The incidence and adjusted risk of Re-MI increased when these variables were clustered (P<0.001). The all-cause mortality rate was significantly higher in patients with Re-MI than in those without (HR: 2.206, P<0.001). CONCLUSIONS: In post-AMI patients treated in the PCI era, the incidence of Re-MI is low compared with that reported during the past 30 years. Patients' clinical factors of diabetes mellitus, history of MI, and advanced age appear to affect the occurrence of Re-MI after hospital discharge, and Re-MI still carries a risk for subsequent mortality.

Oral treatment with nicorandil at discharge is associated with reduced mortality after acute myocardial infarction.

BACKGROUND: Previous studies showed that nicorandil can reduce coronary events in patients with coronary artery disease. However, it is unclear whether oral nicorandil treatment may reduce mortality following acute myocardial infarction (AMI). METHODS AND RESULTS: We examined the impact of oral nicorandil treatment on cardiovascular events in 1846 AMI patients who were hospitalized within 24 h after AMI onset, treated with emergency percutaneous coronary intervention (PCI), and discharged alive. Patients were divided into those with (Group N, n=535) and without (Group C, n=1311) oral nicorandil treatment at discharge. No significant differences in age, gender, body mass index, prevalence of coronary risk factors, or history of myocardial infarction existed between the two groups; however, higher incidences of multi-vessel disease, and a lower rate of successful PCI were observed in Group N. During the median follow-up of 709 (340-1088) days, all-cause mortality rate was 43% lower in Group N compared with Group C (2.4% vs. 4.2%, stratified log-rank test: p=0.0358). Multivariate Cox regression analysis revealed that nicorandil treatment was associated with all-cause death after discharge (Hazard ratio 0.495, 95% CI: 0.254-0.966, p=0.0393), but not for other cardiovascular events such as re-infarction, admission for heart failure, stroke and arrhythmia. CONCLUSIONS: The results suggest that oral administration of nicorandil is associated with reduced incidence of death in the setting of secondary prevention after AMI.

Upfront thrombus aspiration in primary coronary intervention for patients with ST-segment elevation acute myocardial infarction: report of the VAMPIRE (VAcuuM asPIration thrombus REmoval) trial.

OBJECTIVES: This study evaluated safety and efficacy of upfront thrombus aspiration during primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI). BACKGROUND: Distal embolization during primary PCI results in reduced myocardial perfusion and poor clinical outcomes. METHODS: The VAMPIRE (VAcuuM asPIration thrombus REmoval) study was a prospective, randomized, controlled multicenter trial conducted in 23 institutions. Patients (N = 355) presenting within 24 h of STEMI symptoms onset were randomized to primary PCI with (n = 180) or without (n = 175) upfront thrombus aspiration using Nipro's TransVascular Aspiration Catheter (Osaka, Japan). RESULTS: The TransVascular Aspiration Catheter reached the lesion in 100% of cases. It successfully crossed the target obstruction in 86% without any delay in procedure time or time to reperfusion; whereas macroscopic thrombi were removed in 75% of the cases. Procedure success was similar between groups (98.9% vs. 98.3%). There was a trend toward lower incidence of slow or no reflow (primary end point-defined as a Thrombolysis In Myocardial Infarction flow grade <3) in patients treated with aspiration versus conventional primary PCI (12.4% vs. 19.4%, p = 0.07). Rate of myocardial blush grade 3 was higher in the aspiration group (46.0% vs. 20.5%, p < 0.001). Aspiration was most effective in patients presenting after 6 h of symptoms onset (slow flow rate: 8.1% vs. 37.6%, p = 0.01). CONCLUSIONS: This study suggested the safety of primary PCI with upfront thrombectomy using a novel device in patients with STEMI. The study showed a trend toward improved myocardial perfusion and lower clinical events in patients treated with aspiration. Patients presenting late after STEMI appear to benefit the most from thrombectomy.

Progression of left coronary artery dissection during and after aortic replacement in acute type A aortic dissection: a case report.

A 69-year-old man was transferred to our hospital with a diagnosis of acute type A aortic dissection. In the emergent operation, the dissection was found to extend to the orifice of the left coronary artery, but not to the coronary artery itself. The false lumen was closed using glue and sutures with felt strips, and graft replacement of the ascending aorta was performed. However, signs of myocardial ischemia were present after the operation, and the patient's condition continued to be unstable, even though intraaortic balloon pumping was initiated. A coronary angiogram and intravascular ultrasound performed three hours after the operation revealed a left main trunk stenosis due to pulsatile compression of the false lumen, which was caused by the extension of dissection. A coronary artery stent was subsequently deployed in the left main trunk. The patient was discharged four weeks later in a stable condition, although with segmental asynergy of wall motion, due to myocardial damage.

Detection and quantification of embolic particles during percutaneous coronary intervention to stable plaque: it correlates to coronary flow dynamics and myocardial damage.

OBJECTIVES: We detected embolic particles liberated from plaque during percutaneous coronary intervention (PCI) as high-intensity transient signals (HITS) with a Doppler guidewire and studied their impact on coronary flow dynamics and the myocardium in patients with stable angina pectoris. BACKGROUND: These embolic particles during PCI may cause myocardial injury. However, this was difficult to confirm because it was impossible to detect embolic particles. METHODS: We performed balloon angioplasty followed by stenting in 31 patients while monitoring coronary flow velocity. After PCI, we measured average peak velocity at baseline and after infusion of adenosine 5'-triphosphate to calculate coronary flow velocity reserve (CFVR) and coronary resistance index (CRI). In patients with PCI to the left coronary artery (n = 21), we calculated relative CFVR as the ratio of CFVR in the target vessel to that in the reference vessel. We measured cardiac troponin T (cTnT) the day after PCI. RESULTS: HITS were detected in 27 (87%) of 31 patients and the majority were observed after stenting. The total number of HITS was correlated with CRI (r = 0.36, P = 0.049) or relative CFVR (r = 0.65, P = 0.0036) but not with CFVR (r = 0.048, P = 0.82). Thirteen patients showed elevated cTnT (range, 0.05-0.31 ng/ml) and the total number of HITS was greater in those with elevated cTnT than in those without elevated cTnT (24 +/- 9 vs. 10 +/- 7, P = 0.0007). CONCLUSIONS: Embolic particles are frequently observed during PCI to stable plaque and the majority are liberated after stenting. There appears to be a quantitative relationship between amounts of HITS and coronary microvessel dysfunction and minor myocardial injury.

Rapid ventricular pacing can reduce heart motion and facilitate stent deployment to the optimal position during coronary artery stenting: initial experience.

AIMS: We have sometimes encountered difficulty in stent positioning, and managed to achieve optimal positioning of the stent by luck when there was extensive movement of the stent delivery system in association with the cardiac cycle. We assessed the safety and efficacy of rapid ventricular pacing in order to achieve precise positioning of the stent in this percutaneous coronary intervention (PCI) situation. METHODS AND RESULTS: Among 363 patients who underwent PCI, difficulty in positioning of the stent was encountered in 7 consecutive patients due to extensive movement of the stent delivery system. We applied rapid ventricular pacing in these 7 patients. We measured the length of motion of the stent delivery system relative to the coronary artery and systolic blood pressure before and under rapid ventricular pacing at a rate of 160 min-1. The extent of motion was markedly reduced by rapid ventricular pacing (7.3+/-2.6 mm to 1.7+/-0.6 mm; p<0.001). Systolic blood pressure was decreased slightly by rapid ventricular pacing (116+/-15 mmHg to 90+/-7 mmHg; p=0.002), but there were no cases of haemodynamic degeneration or ventricular arrhythmia. CONCLUSIONS: Rapid ventricular pacing is a safe and promising option for precise stent positioning, when movement of the stent delivery system prevents precise deployment.

Marshall vein as arrhythmogenic source in patients with atrial fibrillation: correlation between its anatomy and electrophysiological findings.

BACKGROUND: Atrial fibrillation (AF) may originate from catecholamine-sensitive vein of Marshall (VOM) or its ligament in addition to pulmonary veins (PVs). The anatomy of VOM and its relation to arrhythmogenic foci in the left atrium are unknown. We studied the anatomy of VOM and its relation to foci in patients with AF. METHODS: The study population consisted of 100 patients with AF (mean age, 62 years; chronic AF, n = 15). AF sources were determined at baseline and after isoproterenol administration without sedation. VOM was identified by balloon-occluded coronary sinus (CS) angiography. We determined its anatomy in relation to left PVs. RESULTS: VOM was visualized in 73 patients (73%). Ninety-seven patients had 269 arrhythmogenic foci (PV, n = 77; non-PV, n = 48). Non-PV foci included left atrial posterior wall (24, 9%), left lateral area (12, 4.5%), roof (6, 2.2%), superior vena cava (28, 10.4%), crista terminalis (8, 3.0%), CS (10, 3.7%), and others (10, 3.7%). The incidence of PV foci in the left superior PV (LSPV) was significantly higher in patients with well-developed VOM than in those without (66% vs 42%, P < 0.05). Twenty-eight patients had 30 non-PV foci around the LSPV ostium. We successfully ablated the non-PV foci at the distal end of VOM in 11 patients. The ends of the VOM branches were good markers to search for non-PV foci. Seven of 11 (64%) patients with successful ablation of non-PV foci were free from arrhythmia, whereas only 6 of 17 (35%) were free from arrhythmia in those with residual non-PV foci. CONCLUSIONS: To determine VOM anatomy is important to identify non-PV foci around the ends of VOM.

Usefulness of high-resolution real-time three-dimensional echocardiography to visualize the left ventricular endocardial surface in myocardial infarction.

High-resolution real-time 3-dimensional echocardiography (RT3DE) allows observation of the left ventricular endocardial surface in vivo. This study was performed to characterize the endocardial surface structure and its contractile function in the myocardial infarction (MI) zone in relation to the healing stage. RT3DE was performed in 90 subjects: 10 normal subjects, 50 patients with Q-wave MI 2 weeks after onset (acute MI), and 30 patients >2 months after onset (healed MI). Recordings of the left ventricular endocardial surface allowed observation of the endocardial structure in 76 patients (84%) from the apical window. The endocardial surface of normal myocardium has rough muscle folds that shrink during systole, implying endocardial contraction. In acute MI, the endocardial surface had lost systolic contraction, but appeared as normal surface structure and showed normal acoustic intensity. The endocardial surface of healed MI showed loss of systolic contraction, disappearance of folds (smooth surface), and high acoustic intensity. The frequencies of smooth surface and highest acoustic intensity were significantly higher in healed MI than acute MI (72% vs 32%, 68% vs 37%, p <0.05, respectively). Loss of systolic endocardial contraction was a common finding of Q-wave MI irrespective of the healing stage, and we could roughly estimate the size of the MI from the spatial extent of the noncontractile zone with reasonable reproducibility (r = 0.90, p <0.001). In conclusion, RT3DE is a new modality that allows observation of the structure and contraction of the endocardial surface of the left ventricular wall. We can make rough estimation of the size of the MI and its healing stage from endocardial observation with RT3DE.

Comparison of orifice area by transthoracic three-dimensional Doppler echocardiography versus proximal isovelocity surface area (PISA) method for assessment of mitral regurgitation.

Effective regurgitant orifice area is a useful index of the severity of mitral regurgitation (MR). The calculation of regurgitant orifice area using the proximal isovelocity surface area (PISA) method has some technical limitations. Three-dimensional reconstruction of the MR jet was performed using the Live 3D system on a Sonos 7500 to measure regurgitant orifice area directly in 109 cases of MR. Regurgitant orifice area was also measured by quantitative 2-dimensional echocardiography and by the PISA method. To analyze the shape of the regurgitant orifice, the ratio of the long axis to the short axis of the orifice (the L/S ratio) was calculated. Regurgitant orifice area on 3-dimensional echocardiography showed an almost identical correlation with that obtained by quantitative echocardiography (r = 0.91, p <0.0001, slope = 0.97) regardless of the L/S ratio. It was also significantly correlated with orifice area obtained using the PISA method (r = 0.93, p <0.0001). However, orifice area on 3-dimensional echocardiography was significantly larger than that obtained using the PISA method in the whole study group and in the 62 cases of MR with L/S ratios >1.5, whereas the correlation was almost identical in cases of MR with L/S ratios < or =1.5. Orifice area obtained using the PISA method also underestimated that obtained by quantitative echocardiography in cases of MR with L/S ratios >1.5. Three-dimensional echocardiography provided robust values independent of the eccentricity of the MR jet or of cardiac rhythm. In conclusion, the direct measurement of the regurgitant orifice area of MR with 3-dimensional Doppler echocardiography could be a promising method to overcome the limitations of the PISA method, especially in cases of MR with elliptic orifice shapes.

[Thrombus aspiration therapy for acute coronary syndrome].

Reducing thrombus burden before percutaneous coronary intervention (PCI) may lead to better myocardial reperfusion in patients with acute myocardial infarction (AMI). Thus, several types of devices have been developed to remove intracoronary thrombus during reperfusion therapy, which includes X-sizer, AngioJet, and aspiration devices. There are two important randomized studies by using X-sizer and AngioJet to evaluate the efficacy of thrombus removal, which implied the possible benefit in myocardial tissue reperfusion, but could not prove the beneficial impact on clinical outcomes. As for thrombus aspiration, there also seems to be no data to demonstrate its clinical impact on prognosis. However, the aspiration therapy has been accepted widespread in Japan, mainly because of the practical benefit to clarify the lesion morphology with easy manipulation. Further studies are needed to demonstrate the characteristics of patient or lesion characteristics which are likely to benefit most by thrombus removal therapy or which demand to perform distal protection strategy.

Effect of reactive hyperemia after coronary recanalization on myocardial tissue reperfusion by thrombolysis in myocardial infarction flow grade in acute myocardial infarction.

Thrombolysis In Myocardial Infarction (TIMI) flow grade is widely used to evaluate myocardial tissue reperfusion in acute myocardial infarction (AMI), but the current grading system is incomplete. Therefore, we clarified the regulation of epicardial coronary flow velocity with the progression of microvascular dysfunction in AMI. We studied 36 patients with first anterior AMI. After intervention, we assessed TIMI flow grade and measured average peak velocity (APV) at baseline and after infusion of adenosine triphosphate (48 microg; baseline and hyperemic APVs, respectively) with a Doppler guidewire. We performed myocardial contrast echocardiography after 2 weeks to assess microvascular integrity (good reflow vs no reflow) and left ventriculography at admission and discharge (24 +/- 2 days) to measure regional wall motion (SD/chord). Patients were classified into 3 groups based on TIMI flow grade and microvascular integrity: TIMI grade 3 flow/good reflow (n = 16), TIMI grade 3 flow/no reflow (n = 12), and TIMI grade 2 flow (n = 8). Baseline APV was comparable in the patients with TIMI grade 3 flow but hyperemic APV was higher in patients with TIMI grade 3 flow/good reflow than in those with TIMI grade 3 flow/no reflow (hyperemic APV 59.3 +/- 25.8 vs 32.8 +/- 8.9 cm/s, p <0.01). All patients with TIMI grade 2 flow showed no reflow and the lowest values of baseline and hyperemic APVs. Regional wall motion at discharge was higher in patients with TIMI grade 3 flow/good reflow than in those with TIMI grade 3 flow/no reflow and TIMI grade 2 flow (-1.44 +/- 0.70, -2.69 +/- 0.31, and -2.88 +/- 0.48 SD/chord, respectively, p <0.01). In conclusion, compensatory reactive hyperemia preserves epicardial coronary flow velocity even in patients with microvascular damage, and with the progression of damage, this compensatory hyperemia can no longer preserve epicardial coronary flow velocity, and baseline APV is decreased in TIMI grade 2 flow.

Chronic pre-treatment of statins is associated with the reduction of the no-reflow phenomenon in the patients with reperfused acute myocardial infarction.

AIMS: Early statin treatment has beneficial effects on prognosis after acute coronary syndrome. The no-reflow phenomenon determines the prognosis after acute myocardial infarction. We investigated the effects of statin treatment before admission on the development of the no-reflow after infarction. METHODS AND RESULTS: We performed intracoronary myocardial contrast echocardiography in 293 consecutive patients with acute myocardial infarction undergoing successful primary percutaneous coronary intervention. There were no significant differences in the incidence of the no-reflow between the patients with and without hypercholesterolaemia. The 33 patients receiving chronic statin treatment before admission had lower incidence of the no-reflow than those without it (9.1 and 34.6%, P=0.003). They also showed better wall motion, smaller left ventricular dimensions, and better ejection fraction at 4.9+/-2.2 months later. Multivariable logistic regression analysis revealed that statin pre-treatment was a significant predictor of the no-reflow along with anterior wall infarction, ejection fraction on admission, and additional ST-elevation after reperfusion, whereas total cholesterol was not. CONCLUSION: Chronic pre-treatment with statins could preserve the microvascular integrity after acute myocardial infarction independent of lipid lowering, leading to better functional recovery.

Usefulness of a new grading system based on coronary flow velocity pattern in predicting outcome in patients with acute myocardial infarction having percutaneous coronary intervention.

In acute myocardial infarction, the coronary blood flow velocity waveform changes with the damage in the infarcted myocardium. We developed a grading system using the shorter diastolic deceleration time (DDT), appearance of systolic flow reversal (SFR), and disappearance of systolic anterograde flow. We studied 72 patients with a first anterior acute myocardial infarction. Doppler guidewire monitoring and myocardial contrast echocardiography were performed 10 and 15 minutes after percutaneous coronary intervention, and left ventriculography was performed at discharge (24 +/- 2 days) to measure regional wall motion (SD/chord). Patients were classified into 4 groups according to the coronary blood flow velocity pattern: group I (n = 39), DDT >or=600 ms; group II (n = 10), DDT <600 ms; group III (n = 17), DDT <600 ms with SFR; and group IV (n = 14), DDT <600 ms with SFR and without systolic anterograde flow. The no-reflow phenomenon was observed in no patients in group I, in 3 in group II, in 11 in group III, and all 14 patients in group IV. Regional wall motion was highest in group I and decreased with increasing group number (groups I, II, III, and IV, -1.45 +/- 0.80, -2.36 +/- 0.60, -2.90 +/- 0.50, and -3.20 +/- 0.52 SD/chord, respectively). With the progression of damage in the infarcted myocardium, the DDT shortened first, followed by the appearance of SFR, and then the disappearance of systolic anterograde flow. In conclusion, analysis of the coronary blood flow velocity pattern allows assessment of the severity of microvascular dysfunction and prediction of left ventricular functional outcomes.

Detection of embolic particles with the Doppler guide wire during coronary intervention in patients with acute myocardial infarction: efficacy of distal protection device.

OBJECTIVES: We investigated whether embolic particles could be detected as high-intensity transient signals (HITS) with a Doppler guide wire during percutaneous coronary intervention (PCI) in patients with acute myocardial infarction (AMI) We also assessed whether these signals could be reduced using a distal protection (DP) device. BACKGROUND: Embolization of thrombi and plaque components to the microcirculation is a major complication of PCI in patients with AMI. Embolic particles running in the cerebral artery are detected as HITS by transcranial Doppler ultrasound. METHODS: We prospectively studied 16 consecutive patients with AMI who underwent direct PCI within 24 h after the onset of symptoms. A PercuSurge GuardWire (MedtronicAVE, Santa Rosa, California) was used as the DP device. Eight patients were randomly assigned to the non-DP group, and the remaining eight were assigned to the DP group. Coronary flow velocity was recorded continuously from before the first balloon inflation to after balloon deflation. RESULTS: All patients in the non-DP group had HITS detected (12 +/- 9 counts) within five consecutive beats (4 +/- 1 beat) after balloon deflation, but none were detected in any of the patients in the DP group. CONCLUSIONS: The Doppler guide wire can be used to visually detect and count emboli as HITS, and the DP device is effective for prevention of distal embolization.

Assessing myocardial perfusion with the transthoracic Doppler technique in patients with reperfused anterior myocardial infarction: comparison with angiographic, enzymatic and electrocardiographic indices.

AIMS: Doppler guidewire studies demonstrated that the no-reflow phenomenon in acute myocardial infarction is associated with characteristic coronary blood flow pattern. We investigated the potential of coronary flow measurement with transthoracic Doppler technique to detect the no-flow in the patients with reperfused infarction, and compared it to that of other modalities. METHODS AND RESULTS: We performed intracoronary myocardial contrast echocardiography after successful primary coronary intervention in the 94 patients with first, anterior wall infarction. Coronary blood flow in the left anterior descending artery was detected with transthoracic Doppler echocardiography within 24 h after reperfusion in 83 patients (88.3%). Twenty-two patients with the no-reflow had significantly lower systolic peak velocity (5.1 +/- 4.2 vs. 8.1 +/- 6.2 cm/s, p = 0.04), higher diastolic peak velocity (38.2 +/- 10.3 vs. 30.8 +/- 15.7 cm/s; p = 0.04), and shorter diastolic deceleration time (134 +/- 41 vs. 424 +/- 202 ms; p < 0.0001) than those with good-reflow. Systolic flow reversal was more frequently observed in those with no-reflow (18.2% vs. 3.3%, p = 0 .02). Diastolic deceleration time < 185 ms detected the no-reflow with far higher sensitivity/specificity (95.5%/95.1%) than TIMI frame count (45.5%/91.8%), ST resolution (54.5%/73.8%) and creatinine kinase-MB (54.5%/88.5%). CONCLUSION: Analysing coronary blood flow pattern can detect the no-reflow after anterior infarction better than other angiographic, electrocardiographic and enzymatic modalities.

Myocardial contrast echocardiography with a new calibration method can estimate myocardial viability in patients with myocardial infarction.

OBJECTIVES: We have developed a novel calibration technique applicable for myocardial contrast echocardiography (MCE). We assessed the value of this technique in the recognition of myocardial infarction (MI) and its spatial extent, and we also performed a validation study in normal subjects. BACKGROUND: The heterogeneity of contrast intensity (CI) among myocardial segments limits the clinical use of MCE. METHODS: We performed MCE with a slow-bolus injection of Levovist and recorded end-systolic harmonic power Doppler images at intervals of four heart beats in 15 normal volunteers and 30 patients with MI. We divided the left ventricular (LV) wall into 12 segments and placed the region of interest in the subendocardial region in each segment and in the adjacent LV cavity. We measured calibrated CI (dB) by subtracting the cavity CI from myocardial CI. RESULTS: The mean intersegmental difference in myocardial CI was 15.8 dB at baseline, whereas it was reduced to 6.3 dB after calibration (p < 0.01). Calibrated CI was higher in the kinetic segments than in the akinetic segments (-14.5 +/- 2.3 dB [range -18.7 to -9.9 dB] vs. -22.5 +/- 2.6 dB [-27.8 to -17.7 dB], p < 0.001), and -18.0 dB was the optimal cutoff point to discriminate these from each other. Color-coded mapping of calibrated CI may identify the spatial extent of persistently akinetic myocardium as areas of calibrated CI of

Prediction of the no-reflow phenomenon with ultrasonic tissue characterization in patients with anterior wall acute myocardial infarction.

The no-reflow phenomenon after acute myocardial infarction seems to be related to ischemic injury before reperfusion. Analyzing cardiac cycle-dependent variation of integrated backscatter (IBS) is a unique method to assess myocardial viability. In this study, the ability of ultrasonic tissue characterization with IBS to predict the no-reflow phenomenon was investigated in 90 patients with first anterior wall infarction who underwent successful primary percutaneous coronary intervention. IBS images were recorded on admission (before reperfusion), and the magnitude of the cyclic variation of IBS within the infarct zone was expressed as phase-corrected magnitude (PCM) by giving positive and negative values when it showed synchronous and asynchronous contraction, respectively. Myocardial contrast echocardiography was performed soon after reperfusion, and 21 patients showed substantial no-reflow. They had smaller PCM before reperfusion than patients without no-reflow (-1.6 +/- 1.9 vs 0.7 +/- 2.7 dB, respectively; p = 0.0002). Multivariate logistic regression analysis revealed that PCM before reperfusion and the number of Q waves were the independent predictors of no reflow. Using -1.0 dB as the cut-off point, PCM predicted no reflow with 66.7% sensitivity and 81.2% specificity. These results indicate that the analysis of myocardial IBS could predict the no-reflow phenomenon before reperfusion.

Usefulness of impairment of coronary microcirculation in predicting left ventricular dilation after acute myocardial infarction.

The goals of this study were to assess the serial change in coronary blood flow velocity (CBFV) patterns with transthoracic Doppler echocardiography and to decide optimal timing to predict left ventricular (LV) remodeling in patients with anterior acute myocardial infarction. We recorded CBFV of the left anterior descending (LAD) coronary artery with transthoracic Doppler echocardiography and measured diastolic deceleration time (DDT, measured in milliseconds) on days 2, 7, and 21 in 52 patients with anterior acute myocardial infarction treated with primary coronary angioplasty. On day 2, DDT was >/=600 ms in 21 patients (group A) and <600 ms in the other 31 patients (group B). In group B, DDT increased to >/=600 ms in 12 patients on day 7 (group B1), and DDT was still <600 ms in the other 19 patients (group B2). However, DDT became comparable among 3 groups on day 21. Group B2 patients had significant chronic LV dilation (LV end-diastolic volume index in groups A, B1, and B2 at 6 months: 74 +/- 16 vs 81 +/- 17 vs 100 +/- 22. ml/m(2), respectively; p <0.05 vs other groups). Multivariate analysis revealed that DDT <600 ms on day 7 was the only independent variable related to LV remodeling. In conclusion, the CBFV pattern changed toward normalization with time in patients with acute myocardial infarction. Time taken for normalization varied among patients. Persistence of microvascular dysfunction up to 7 days after reperfusion predicted LV remodeling.

Detection of TIMI-3 flow before mechanical reperfusion with ultrasonic tissue characterization in patients with anterior wall acute myocardial infarction.

BACKGROUND: Spontaneous coronary reperfusion with TIMI-3 flow is associated with favorable clinical outcomes in patients with acute myocardial infarction (AMI). We investigated the ability of analyzing cardiac cycle-dependent variation of myocardial integrated backscatter (IBS) for predicting spontaneous reperfusion in anterior AMI. METHODS AND RESULTS: We recorded IBS images on admission in 104 patients with first anterior wall AMI and subsequently performed coronary angiography and coronary intervention. We measured the cyclic variation of IBS within the infarct zone and expressed its magnitude as phase-corrected magnitude (PCM) by giving positive and negative values when it showed synchronous and asynchronous contraction, respectively. Twenty-three patients showing TIMI-3 flow at the initial coronary angiography had smaller peak creatine kinase value than 57 patients with initial TIMI-0/1 flow (864+/-961 versus 2358+/-1757 IU/L; P=0.0002) and better percent wall thickening within risk area (36.1+/-15.1%) than those with TIMI-2 (16.7+/-12.8%, P<0.0001) or TIMI-0/1 (5.1+/-11.6, P<0.0001). The patients with initial TIMI-3 had higher PCM (2.7+/-1.3 dB) than those with TIMI-2 (-0.3+/-2.2 dB, P<0.0001) or those with TIMI-0/1 (-1.1+/-2.4 dB, P<0.0001). Using PCM=1.0 dB as the cutoff point, PCM detected TIMI-3 flow with 95.7% sensitivity and 90.1% specificity. Multivariable logistic regression analysis revealed that only PCM is an independent predictor for spontaneous reperfusion among the hemodynamic, echocardiographic, and electrocardiographic variables. CONCLUSIONS: Analysis of myocardial IBS could detect spontaneous reperfusion noninvasively in the emergent stage of anterior AMI.