Characterization of hibernating myocardium with NOGA electroanatomic endocardial mapping

Because the terms "hibernation" and "viability" are not interchangeable, the recognition of hibernating myocardium within viable segments remained elusive for NOGA electroanatomic endocardial mapping. The aim of the present study was to determine the characteristics of hibernating myocardium in NOGA mapping. Baseline and follow-up endocardial mapping, thallium-201 myocardial perfusion scintigraphy at rest, and contrast ventriculography were performed in 28 patients who had proved viable myocardium before and 7.3 +/- 2.5 months after percutaneous coronary intervention. Significantly improved regional wall motion in the revascularized territory (region of interest) was confirmed in 9 patients (group 1) at follow-up (from -2.11 +/- 0.87 to -1.48 +/- 0.43 SD/chord, p <0.05), whereas no change in regional wall motion was observed in 19 patients (group 2; from -2.56 +/- 0.88 to -2.79 +/- 0.91 SD/chord). Average normalized thallium uptake at rest increased significantly in groups 1 and 2 after revascularization. A trend toward increased unipolar voltages in the region of interest was observed in group 1 at follow-up (from 10.6 +/- 3.5 to 11.7 +/- 4.0 mV, p = 0.073), whereas no change was observed in group 2 (from 8.7 +/- 4.4 to 8.9 +/- 3.8 mV). A significant increase in local linear shortening was measured only in group 1 (from 7.5 +/- 5.2% to 10.3 +/- 3.9%, p <0.05). Hibernating myocardial segments exhibited significantly higher unipolar voltages and late thallium uptake at rest at baseline. Receiver-operator characteristic analysis showed a mean unipolar voltage of 9.0 mV (predictive accuracy 0.708, common sensitivity and specificity 72%) in the region of interest for prediction of functional recovery. In conclusion, for characterizing the hibernating myocardium within viable segments, NOGA endocardial mapping offers on-line guidance for percutaneous coronary and noncoronary myocardial revascularization.     

Electromechanical characterization of myocardial hibernation in a pig model.

BACKGROUND: This study attempted to assess in-vivo electromechanical changes following gradual coronary artery occlusion in a pig ameroid constrictor model using a novel three-dimensional left ventricular mapping system. METHODS AND RESULTS: We measured unipolar and bipolar voltage potentials and local endocardial shortening in the ischemic lateral and non-ischemic anterior zones in animals at rest (n = 9) 5 weeks after the implantation of ameroid constrictors around the left circumflex artery. Echocardiography was used to assess regional contractility (percentage myocardial thickening), and an echo-contrast perfusion study was performed using acoustic densitometry methods. The ischemic lateral zone showed reduced myocardial perfusion at rest (peak intensity; 3.4 +/- 1.7 versus 20.7 +/- 14.8, P = 0.005), impaired mechanical function (percentage wall thickening 22 +/- 19% versus 40 +/- 11%, P = 0.03; local endocardial shortening 2.9 +/- 5.5% versus 11.7 +/- 2.1%, P = 0.002), and preserved electrical activity (unipolar voltage 12.4 +/- 4.7 versus 14.4 +/- 1.9 mV, P = 0.25; bipolar voltage 4.1 +/- 1.1 versus 3.8 +/- 1.5 mV, P = 0.62), compared with the anterior region. CONCLUSIONS: Gradual coronary artery occlusion resulting in regional reduced perfusion and function at rest (i.e. hibernating myocardium) is characterized by preserved electrical activity. An electromechanical left ventricular mapping procedure such as the one described here may be of diagnostic value for identifying the hibernating myocardium.     

Management of multivessel coronary disease after ST elevation myocardial infarction treated by primary angioplasty

BACKGROUND: Optimal treatment strategy of patients with ST elevation myocardial infarction (STEMI) and multivessel coronary artery disease (CAD) undergoing primary angioplasty is still unclear. Percutaneous coronary intervention (PCI) of non-culprit vessels simultaneously or soon after primary angioplasty is feasible and safe, but available data failed to consistently show a benefit in long-term clinical outcomes. METHODS: We retrospectively compared in-hospital and long-term outcomes for patients with STEMI and multivessel CAD treated by primary angioplasty with (Group 1, n=64) or without (Group 2, n=46) early, staged PCI of other angiographically significant coronary lesions. In-hospital major adverse cardiovascular events (MACE) were defined as a composite of death, periprocedural myocardial infarction after staged, elective PCI, stroke, stent thrombosis, major bleeding, and vascular complications. MACE at follow-up were defined as a composite of death, stroke, stent thrombosis, any coronary revascularization, and re-hospitalization for acute coronary syndrome. RESULTS: Group 1 patients underwent staged PCI 5.9 +/- 3.5 days after primary angioplasty. The mean length of follow-up was 13 months (392 +/- 236 days). The incidence of in-hospital MACE was 20.3% in Group 1 and 10.8% in Group 2 (P=0.186); the incidence of out of hospital MACE was 9.3% in Group 1 and 23.9% in Group 2 (P=0.037). In Group 1 in-hospital MACE were driven by periprocedural myocardial infarction after the elective procedure, which occurred in 15.6% of patients. CONCLUSIONS: Our data show that multivessel, staged PCI in STEMI patients is associated with a low incidence of adverse events at follow-up but with a higher incidence of in-hospital MACE, mainly driven by periprocedural myocardial infarction during the elective procedure.     

Primary coronary angioplasty in patients with ST segment elevation acute myocardial infarction and diabetes

BACKGROUND: Subjects with diabetes constitute 13-25% of patients with ST segment elevation acute myocardial infarction (STEMI). In spite of the introduction of thrombolytic therapy, patients with STEMI and diabetes continue to have worse prognosis than those without diabetes. Primary percutaneous coronary intervention (PCI) has been shown in recent years to be the most effective therapy in patients with STEMI. AIM: To compare the outcome of STEMI patients with or without diabetes who underwent primary PCI. METHODS: The study group consisted of 500 consecutive patients with STEMI. The occurrence of major adverse cardiac events (MACE) which included death, reinfarction or repeated PCI of the target vessel, was analysed peri-operatively and during a six-month follow-up period.Results. Diabetes was diagnosed in 68 (13.6%) patients. The mean time duration from the onset of STEMI symptoms to treatment was similar in patients with or without diabetes (230+/-97 min vs 231+/-139 min, NS). Patients with diabetes were older (61.9+/-8.9 vs 57.9+/-10.8 years, p=0.004), had higher body mass index (29+/-4 vs 27+/-5, p=0.002), more frequent history of coronary artery disease (57.4% vs 37.9%, p=0.002), higher prevalence of arterial hypertension (71.6% vs 56.8%, p=0.02) and more frequently the left anterior descending artery as the infarct-related artery (58.8% vs 42.1%, p=0.01). Immediately after PCI, epicardial and myocardial reperfusion rates were lower in patients with rather than without diabetes (TIMI 3: 84.9% vs 91.3%, p=NS, cTFC: 32+/-26 vs 22+/-16, p<0.0001, and MPG3: 25% vs 41.9% p=0.008). Diabetes increased the risk of MACE during in-hospital period by 2.7 times. The rate of MACE during a six-month follow-up period was almost two times higher in patients with rather than without diabetes (death: 8.8% vs 5.1%, reinfarction: 1.5% vs 1.2%, repeated PCI: 11.8% vs 6.9%). CONCLUSIONS: Primary PCI-achieved epicardial and myocardial reperfusion rate is lower in STEMI patients with rather than without diabetes. The presence of diabetes almost doubles the risk of MACE during a six-month follow-up.     

Catheter-based electromechanical mapping to assess regional myocardial function: a comparative analysis with transthoracic echocardiography.

Recent studies using a nonfluoroscopic three-dimensional left ventricular mapping system showed considerable changes in voltage potentials and mechanical activity detected in ischemic and infarcted myocardial regions with mechanical dysfunction. This study examined the electromechanical characteristics in relation to regional wall motion assessed by echocardiography in patients with coronary artery disease. A 12-segment model of mapping (apical, mid, basal of septal, anterior, lateral, and inferior/posterior segments) was compared to echo wall motion score in 74 patients (836 segments). Unipolar voltage and local endocardial shortening signals were distinguished according to graded echo segmental rest scores (0 = normal, 1 = mild hypokinesis, 2 = moderate hypokinesis, 3 = severe hypokinesis, 4 = akinesis). Results show a significant difference in voltage potentials and shortening values in groups distinguished according to echocardiography motion score. The average voltage potentials and shortening values were highest in myocardial segments with normal or slightly reduced contractility and lowest in myocardial segments with moderate to severely impaired contractility scores (voltage: 12.3 +/- 5.0, 12.1 +/- 5.3, 10.7 +/- 5.4, 8.7 +/- 3.9, 7.1 +/- 3.0 mV, P = 0.0001; local shortening: 9.7 +/- 6.5, 8.4 +/- 5.9, 8.0 +/- 5.4, 5.6 +/- 6.3, 5.1 +/- 4.6%, P = 0.0001 in regions with segmental scores of 0, 1, 2, 3, 4 by echo, respectively). Using receiver-operating curve calculations, the area under the curve was 0.72 +/- 0.06 (voltage) and 0.67 +/- 0.05 (local shortening) without a significant difference between the two curves. The 90% thresholds for defining preserved vs. impaired contractility were 12.8 and 5.6 mV for voltage and 12.6% and 1.6% for local shortening. We conclude that electromechanical mapping correlates with regional changes in wall motion scores assessed by echo, showing a gradual proportional decrease in measured voltage and shortening signals in segments with impaired function.     

Percutaneous thrombectomy with the RESCUE system in acute myocardial infarction

BACKGROUND: Percutaneous coronary interventions (PCI) in acute myocardial infarction with ST segment elevation (STEMI) are associated with distal coronary embolisation. It may be speculated that percutaneous thrombectomy preceding stent implantation may prevent coronary microcirculation from embolisation. AIM: To assess safety and efficacy of percutaneous thrombectomy in patients with STEMI. METHODS: Seventy two patients with STEMI were randomised to PCI with stent implantation alone (n=32) or percutaneous thrombectomy with the RESCUE system, followed by stent implantation (n=40). Coronary flow in infarct related artery before and after the procedure was assessed using TIMI scale and corrected TIMI frame count - cTFC. Myocardial blood flow was measured using TIMI myocardial perfusion grade - tMPG. The degree of ST segment resolution 60 min after PCI was also assessed. Left ventricular ejection fraction (LVEF) was measured in hospital and three months later. RESULTS: The two groups did not differ with respect to the time from the onset of symptoms to the procedure (236+/-162 min vs 258+/-198 min, NS) or the baseline TIMI, cTFC and tMPG values. An effective thrombectomy procedure was performed in 35 (87%) patients from group B. After the procedure, the number of patients with TIMI 3 grade as well as cTFC values and the proportion of patients with tMPG 3 were similar in both groups (86% vs 85%, NS; 19 vs 21, NS; and 38% vs 54%, NS). The sum of ST segment elevations after the procedure was significantly greater in patients who underwent PCI only compared with patients who had thrombectomy and PCI (6.8+/-5.2 mm vs 3.6+/-2.9 mm, p=0.004). Complete normalisation of ST segment was achieved in 68% of patients treated with thrombectomy and PCI compared with 25% of patients who had PCI only (p=0.005). CK-MB peak values occurred significantly earlier in patients treated with thrombectomy (92.1% vs 66.7% up to 360 min, p=0.01). After 3 months of follow-up, LVEF tended to be greater in patients treated with thrombectomy and PCI than in those who underwent PCI only (55.3+/-14.7% vs 60.3+/-9.2%, NS). CONCLUSIONS: Thrombectomy with the RESCUE system in patients with STEMI is safe and effectively restores patency of infarct related artery. Thrombectomy better improves myocardial perfusion than standard PCI.     

Electromechanical mapping for determination of myocardial contractility and viability. A comparison with echocardiography,myocardial single-photon emission computed tomography,and positron emission tomography

OBJECTIVE: The purpose of this study was to validate electromechanical viability parameters with combined myocardial perfusion and metabolic imaging and echocardiography. BACKGROUND: The NOGA System is a catheter-based, non-fluoroscopic, three-dimensional endocardial mapping system. This unique technique allows accurate simultaneous assessment of both local electrical activity and regional contractility. METHODS: The results of NOGA, myocardial single-photon emission computed tomography (SPECT), positron emission tomography, and echocardiography in 51 patients with coronary artery disease and a pathologic SPECT study were transcribed in a nine-segment bull's-eye projection and compared.The local shortening of normally contracting segments, as shown by echocardiography, was 9.2 +/- 5.1%, which decreased to 6.6 +/- 5.0% and 4.1 +/- 5.2% in hypokinetic and akinetic segments. The highest unipolar voltage (11.2 +/- 5.0 mV) and local shortening (8.2 +/- 5.0%) characterized normally perfused segments. Fixed perfusion defects with normal or limited 18-fluoro-2-deoxy-D-glucose uptake indicating viability had a significantly higher unipolar voltage than did scar tissue (7.25 +/- 2.7 vs. 5.0 +/- 3.1 mV, p = 0.029). CONCLUSION: Electromechanical parameters sufficiently defined the viability state of the myocardium and showed good concordance with the findings by nuclear perfusion and metabolism imaging and echocardiography. The NOGA technique provides all the relevant information immediately after coronary angiography and enables the physician to proceed with therapy in the same setting.     

辛伐他汀对急性心肌梗死冠状动脉经皮介入治疗后心肌血流灌注的影响

目的 探讨辛伐他汀对急性心肌梗死患者急诊冠状动脉经皮介入治疗术后心肌血流灌注的影响.方法 81例行急诊冠状动脉经皮介入治疗术的急性心肌梗死患者,按之前服用辛伐他汀的情况分为四组:A组15例,服用时间超过6个月;B组19例,服用时间1～6个月;C组17例,服用时间少于1个月;D组30例,未服用.比较各组校正的TIMI帧数计数(CTFC)和1 h内ST段回落情况.结果 A组和B组CTFC较D组较小(P＜0.01),且术后1 h ST段回落较D组明显(P＜0.01).结论 长期服用辛伐他汀,可有效改善急性心肌梗死患者急诊冠状动脉经皮介入治疗术后心肌血流灌注.     

Electromechanical mapping versus positron emission tomography and single photon emission computed tomography for the detection of myocardial viability in patients with ischemic cardiomyopathy

OBJECTIVES: We compared catheter-based electromechanical mapping (NOGA system, Biosense-Webster, Haifa, Israel) with positron emission tomography (PET) and single photon emission computed tomography (SPECT) for prediction of reversibly dysfunctional myocardium (RDM) and irreversibly dysfunctional myocardium (IDM) in patients with severe left ventricular dysfunction. Furthermore, we established the optimal discriminatory value of NOGA measurements for distinction between RDM and IDM. BACKGROUND: The NOGA system can detect viable myocardium but has not been used for prediction of post-revascularization contractile function in patients with ischemic cardiomyopathy. METHODS: Twenty patients (19 males, age [mean +/- SD] 60 +/- 16 years, ejection fraction [EF] 29 +/- 6%) underwent viability testing with NOGA and PET or SPECT before revascularization. Left ventricular function was studied at baseline and six months after revascularization. RESULTS: The EF increased to 34 +/- 13% at six months (p < 0.05 vs. baseline). The 58 RDM and 57 IDM regions differed with regard to unipolar voltage amplitude (UVA) (9.2 +/- 3.9 mV vs. 7.6 +/- 4.0 mV, p < 0.05), normalized UVA (106 +/- 54% vs. 75 +/- 39%, p < 0.05), and tracer uptake (76 +/- 17% vs. 60 +/- 20%, p < 0.05). The NOGA local shortening did not distinguish between RDM and IDM (6.4 +/- 5.8% vs. 5.4 +/- 6.6%). By receiver operating characteristic curve analysis, myocardial tracer uptake had better diagnostic performance than UVA (area under curve [AUC] +/- SE: 0.82 +/- 0.04 vs. 0.63 +/- 0.05, p < 0.05) and normalized UVA (AUC +/- SE: 0.70 +/- 0.05, p < 0.05). Optimal threshold was defined as the value yielding sensitivity = specificity for prediction of RDM. Sensitivity and specificity were 59% at a UVA of 8.4 mV, 65% at a normalized UVA of 83%, and 78% at a tracer uptake of 69%. CONCLUSIONS: The NOGA system may discriminate RDM from IDM with optimal discriminatory values for UVA and normalized UVA of 8.4 mV and 83%, respectively. However, the diagnostic performance does not reach the level obtained by PET and SPECT in patients with severe heart failure.     

Assessment of percutaneous coronary intervention on regional and global left ventricular function in patients with chronic total occlusions

BACKGROUND: The improvement of regional and global ventricular function following percutaneous coronary intervention (PCI) with reperfusion of the artery supplying the infarct area in acute myocardial infarction is well-described. However, little is known of the potential effects of late recanalization of chronic coronary artery occlusion on left ventricular function. OBJECTIVE: To determine whether PCI improves regional and global left ventricular function in patients with chronic coronary artery occlusions. PATIENTS AND METHODS: Thirty-five patients having at least one coronary artery occluded for six weeks or longer were included in the present prospective study. Exercise thallium-201 myocardial perfusion scintigraphy, multiple-gated acquisition ventriculography and two-dimensional echocardiography were performed in 19 patients (16 men; mean age of 58+/-5 years) who underwent a successful PCI to assess both regional and global left ventricular function before and six weeks following the procedure. RESULTS: The mean ejection fractions before and after reperfusion were 51+/-7% and 58+/-6% using Simpson's method (P<0.001) by echocardiography, and 45+/-1% and 53+/-1% (P=0.01) by multiple-gated acquisition ventriculography, respectively. The echocardiographic wall motion score was 24+/-9 before and 15+/-6 after PCI (P<0.001). The exercise perfusion score (21+/-1 and 14+/-1 [P=0.01]), rest perfusion score (15+/-1 and 12+/-1 [P=0.02]) and reinjection perfusion score (14+/-1 and 11.1+/-1 [P=0.07]) also improved after PCI. The presence of angina was strongly associated with an improvement in left ventricular function and wall motion score (P<0.01). CONCLUSIONS: PCI significantly improved the regional and global left ventricular function in patients with chronic total coronary occlusion. This procedure may provide symptom benefits in selected patients.     

Does Proximal Location of Culprit Lesion Confer Worse Prognosis in Patients Undergoing Primary Percutaneous Coronary Intervention for ST Elevation Myocardial Infarction?

ST segment elevation myocardial infarction (STEMI) from proximally located culprit lesion is associated with greater myocardium at jeopardy. In STEMI patients treated with thrombolytics, proximal culprit lesions are known to have worse prognosis. This relation has not been studied in patients undergoing primary percutaneous coronary intervention (PCI). In 3,535 STEMI patients with native coronary artery occlusion pooled from the primary angioplasty in myocardial infarction database, we compared in-hospital and 1-year outcomes between those with proximal (n = 1,606) versus non-proximal (n = 1,929) culprit lesions. Patients with proximal culprits were more likely to die and suffer major adverse cardiovascular events (MACE) during the index hospital stay (3.8% vs 2.2%, P = 0.006; 8.2% vs 5.8%, P = 0.0066, respectively) as well as during 1-year follow-up (6.9% vs 4.5%, P = 0.0013; 22% vs 17%, P = 0.003, respectively) compared to those with non-proximal culprits. After adjustment for baseline differences, proximal culprit was independently predictive of in-hospital death (adjusted odds ratio% 1.58, 95% confidence intervals, CI 1.05-2.40) and MACE (OR 1.41, CI 1.06-1.86), but not 1-year death or MACE. In addition, proximal culprit was independently associated with higher incidence of ventricular arrhythmias and sustained hypotension during the index hospitalization. The univariate impact of proximal culprit lesion on in-hospital death and MACE was comparable to other adverse angiographic characteristics, such as multivessel disease and poor initial thrombolysis in myocardial infarction flow, and greater than that of anterior wall STEMI. In conclusion, proximal location of the culprit lesion is a strong independent predictor of worse in-hospital outcomes in patients with STEMI undergoing primary PCI.     

Re-elevation of T-wave from day 2 to day 4 after successful percutaneous coronary intervention predicts chronic cardiac systolic dysfunction in patients with first anterior acute myocardial infarction

This study evaluates the clinical significance of re-elevation of T-wave in patients with ST segment elevation acute myocardial infarction (STEMI) undergoing successful percutaneous coronary intervention (PCI). Resolution of ST elevation within 24 h after reperfusion is associated with better outcome. However, little is known about the serial electrocardiography (ECG) changes and their significance. Seventy-five patients (52 men; 66 ± 1 years) with the first anterior STEMI in whom 12-lead ECG was recorded every day from day 0 to day 8 after PCI were studied. JT interval was quartered (points 1–5), and the deviations from isoelectric line at each point were analyzed in leads V2, V3, and V4. Serial ECG showed ST resolution and T-wave inversion within 2 days after PCI in all patients at the middle of JT interval (point 3), and subsequent re-elevation of T-wave on day 4 in 73 patients (97.3 %). The patients were divided into two groups: Group A (n = 37) with less JT deviation changes (<0.25 mV) from day 2 to day 4 at point 3; and Group B (n = 38) with greater JT deviation changes (≥0.25 mV). Group B had less retrograde collateral flow and longer JT interval in the acute phase, and lower left ventricular ejection fraction (LVEF), worse regional contractility, and higher plasma brain natriuretic peptide levels at 6 months after the onset than Group A (all P < 0.05). The JT deviation change was negatively correlated with and an independent predictor for LVEF in the chronic phase. Re-elevation ≥0.25 mV of T-wave at the middle of JT interval after successful PCI predicts chronic cardiac systolic dysfunction in patients with first anterior STEMI.     

Electrophysiological and arrhythmogenic effects of intramyocardial bone marrow cell injection in patients with chronic ischemic heart disease

BACKGROUND: Bone marrow cell injection has been introduced to treat patients with ischemic heart disease. However, focal application of bone marrow cells may generate an arrhythmogenic substrate. OBJECTIVES: To assess the electrophysiological and arrhythmogenic effects of intramyocardial bone marrow cell injection in patients with chronic myocardial ischemia. METHODS: Bone marrow was aspirated in 20 patients (65+/-11 years, 19 male) with drug-refractory angina and myocardial ischemia. Electroanatomical mapping (NOGA, Biosense-Webster, Waterloo, Belgium) was performed during mononuclear cell isolation. Areas for cell injection were selected based on the localization of ischemia on SPECT. These areas were mapped in detail to evaluate local bipolar electrogram duration, amplitude and fragmentation. Mononuclear cells were injected in the ischemic area with the NOGA system. SPECT and electroanatomical mapping were repeated at 3 months. Holter monitoring was repeated at 3 and 6 months. RESULTS: SPECT revealed a decrease in the number of segments with ischemia (3.5+/-2.5 vs. 1.1+/-1.0 at 3 months; P<0.01) and an increased left ventricular ejection fraction (44+/-13% vs. 49+/-17% at 3 months; P=0.02). The number of ventricular premature beats remained unchanged (10+/-24x10(2)/24h vs. 8+/-23x10(2)/24h at 3 months (P=NS) and 12+/-30x10(2)/24h at 6 months (P=NS)). At 3 months follow-up, bone marrow cell injection did not prolong electrogram duration (15.9+/-4.6 ms vs. 15.6+/-4.0 ms; P=NS), decrease electrogram amplitude (3.8+/-1.5 mV vs. 3.8+/-1.5 mV; P=NS), or increase fragmentation (2.0+/-0.5 vs. 1.9+/-0.4; P=NS). CONCLUSION: Intramyocardial bone marrow cell injection does not increase the incidence of ventricular arrhythmias and does not alter the electrophysiological properties of the injected myocardium.     

Comparison of accuracy in the prediction of left ventricular wall motion changes between invasively assessed microvascular integrity indexes and fluorine-18 fluorodeoxyglucose positron emission tomography in patients with ST-elevation myocardial infarction

We compared the accuracy in predicting regional wall motion score index (RWMSI) changes between microvascular integrity indexes measured during primary percutaneous coronary intervention (PCI) and fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) in ST-elevation myocardial infarction (STEMI). Fifty patients with STEMI were enrolled. Microvascular integrity indexes were measured using an intracoronary Doppler wire and a pressure wire after primary PCI. We performed FDG-PET 7 days after PCI. RWMSI on follow-up echocardiogram (5.8 +/- 1.7 months) revealed good correlations with coronary flow reserve (r = -0.442, p = 0.002), diastolic deceleration time (r = -0.511, p <0.001), microvascular resistance index (r = 0.443, p = 0.002), coronary wedge pressure (r = 0.474, p <0.001), and FDG uptake rate (r = -0.571, p <0.001). There were no significant differences in areas under the curve for predicting RWMSI changes between microvascular integrity indexes and FDG-PET (coronary flow reserve 0.696, diastolic deceleration time 0.731, microvascular resistance index 0.748, coronary wedge pressure 0.694, Thrombolysis In Myocardial Infarction myocardial perfusion grade 0.702, and FDG-PET 0.755). In conclusion, microvascular integrity indexes assessed during primary PCI are useful and comparable to FDG-PET in predicting left ventricular functional changes in STEMI.     

提前应用替罗非班对急性ST段抬高心肌梗死患者急诊介入治疗疗效的影响

目的通过随机对比分析,探讨急性ST段抬高心肌梗死(STEMI)患者急诊经皮冠状动脉介入治疗(PCI)时,提前应用血小板糖蛋白(GP)Ⅱb/Ⅲa受体拮抗剂替罗非班是否安全,以及能否进一步改善急诊PCI疗效。方法2005年4月至2006年4月,160例拟诊急性STEMI的患者接受急诊PCI时联合应用替罗非班,最终158例患者纳入研究,其中男性117例,女性41例,平均年龄58.8±25.2岁(36～78岁)。将患者随机分为两组,第一组共80例,在急诊冠状动脉造影结束后开始应用为常规使用组,第二组78例,在获取知情同意后在急诊室即开始应用者为早期使用组。比较两组间的基础临床状况、术前梗死相关血管前向血流情况,术后血流情况以及出血事件与近期心血管事件。结果两组基础临床情况差异无统计学意义,早期使用组提前39.8min应用替罗非班。早期组术前IRA前向血流达到TIMI2～3级的比率高于常规组(分别为39.7%和23.8%,P=0.040),其中达到TIMI3级的比率亦显著高于常规组(分别为23.1%和10.0%,P=0.032)。两组术后TIMI3级获得率,校正的TIMI计帧数和Blush3级获得率差异无统计学意义。两组近期主要心血管事件发生率、出血事件与血小板减少症发生率差异无统计学意义。结论急性STEMI患者急诊PCI前提前应用替罗非班是安全的,虽然术后造影结果和临床预后并没有明显改善,但是提前应用替罗非班可以提高PCI前的梗死相关血管前向血流。需要设计更大的样本量,更早的应用时机和合适的较大剂量提前应用替罗非班进一步深入研究。     

The value of stress single-photon emission computed tomography imaging performed routinely at 6 months in asymptomatic patients for predicting angiographic restenosis after successful direct percutaneous intervention for acute ST elevation myocardial infarction

AIMS: The authors tested the value of stress single-photon emission computed tomography (SPECT) imaging performed systematically for detecting angiographic restenosis in asymptomatic patients who underwent direct percutaneous coronary intervention (PCI) for acute ST segment elevation myocardial infarction (STEMI). Angiographic restenosis of the infarct-related artery after direct PCI for STEMI is often silent and the strategy for follow-up evaluation of asymptomatic patients remains debated. METHODS: A total of 149 patients successfully treated by direct PCI (96% stenting) for STEMI with no symptoms during the follow-up systematically underwent both rest thallium 201/stress Tc 99m setamibi myocardial perfusion imaging and coronary angiogram at 6 months. Patients were followed up for 2.5+/-0.5 years after 6 months control for cardiac events. RESULTS: In the 149 patients, the sensitivity, specificity, positive and negative predictive values and accuracy of SPECT imaging were 48, 61, 35, 72 and 57%, respectively, for detecting binary angiographic restenosis defined as > or =50% diameter stenosis. Whether stress testing was maximal or performed after withheld anti-ischemic drugs did not improve the results. Reversible ischemia at SPECT in the infarct territory did not predict long-term cardiac events. CONCLUSION: These data suggest a poor correlation between stress SPECT imaging and angiographic restenosis at 6 months in patients treated by direct PCI for STEMI who remain asymptomatic at follow-up. The long-term clinical prognostic value of SPECT reversible ischemia in the infarct territory appears also limited in this peculiar subset of patients. These findings should be taken into account in the strategy of the clinical follow-up of this population.     

Clinical benefits of adjunctive tirofiban therapy in patients with acute ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention

BACKGROUND: There is continued debate as to whether a combined reperfusion regimen with platelet glycoprotein IIb/IIIa inhibitor-tirofiban provides additional benefit in optimal myocardial reperfusion for patients with acute ST-segment elevation myocardial infarction (STEMI). This study was conducted to investigate the clinical benefits of adjunctive tirofiban therapy combined with primary percutaneous coronary intervention (PCI) in patients with STEMI. METHODS: One hundred and seventy-two consecutive patients with STEMI presented within 12 h of symptoms were randomly allocated to primary PCI combined with early (upstream group, n=57) or late administration of tirofiban (downstream group, n=57) or primary PCI treatment alone (control group, n=58). Clinical characteristics, angiographic findings, and in-hospital outcomes were compared between groups, as well as left ventricular ejection fraction (LVEF) and major adverse cardiac events (MACE, including death, reinfarction and target vessel revascularization) at 30-day and 6-month clinical follow-up. RESULTS: Despite comparable baseline clinical features among three groups, angiographic and procedural characteristics and outcomes differed significantly between patients receiving tirofiban treatment and controls, with respect to preprocedural (upstream: 28.1%, downstream: 7.0%, control: 5.2%, P<0.001) and postprocedural thrombolysis in myocardial infarction (TIMI) grade 3 flow of infarct-related artery (98.2, 94.7, 86.2%, P=0.03), TIMI myocardial perfusion grade 3 (75.4, 70.2, 53.4%, P=0.03), corrected TIMI frame count (20.4+/-5.0, 23.1+/-5.3, 32.2+/-6.7, P<0.001), resolution of the sum of ST-segment elevation (6.16+/-1.21, 6.02+/-1.09, 4.53+/-2.65 mm, P<0.001), peak value of creatine kinase-MB (218.0+/-72.5, 224.2+/-69.4, 255.3+/-77.0 ng/ml, P=0.02) and troponin I (76.0+/-21.5, 79.8+/-18.7, 86.4+/-11.0 ng/ml, P=0.007), and average hospital stay (10.6+/-5.4, 12.6+/-4.7, 14.5+/-6.5 days, P=0.001). The MACE rate at 30 days (3.5, 5.3, 15.5%, P=0.04) was reduced and LVEF (0.51+/-0.07, 0.50+/-0.07, 0.47+/-0.08, P=0.008) was higher in upstream and downstream groups than in controls. At 6-month follow-up, the MACE rate was not significantly different among groups (7.0, 8.8, 17.2%, P=0.17), but LVEF in upstream and downstream groups was significantly improved (0.59+/-0.06, 0.57+/-0.07, 0.54+/-0.07, P<0.001). Subgroup analysis demonstrated a statistically significant difference between upstream and downstream groups in preprocedural TIMI grade 3 flow (P=0.003) and postprocedural corrected TIMI frame count (P=0.007), which resulted in a shortened hospital stay (P=0.04), reduction of MACE rate at 30-day and 6-month follow-up by 34 and 20%, respectively. Multivariate logistic analysis revealed that age more than 65 years [odds ratio (OR)=3.42, P<0.01], tirofiban therapy (OR=0.56, P<0.05) and LVEF less than 0.5 during hospitalization (OR=2.56, P<0.01) were major independent predictors of MACE at 6-month clinical follow-up. No significant difference in hemorrhagic complications among three groups was noted (upstream: 10.5%, downstream: 12.3%, control: 6.9%, P=0.61). CONCLUSION: This prospective study indicates that adjunctive tirofiban therapy for patients with STEMI who undergo primary PCI can significantly improve reperfusion level in the infarct area, clinical outcomes at 30-day and 6-month follow-up, especially with upstream tirofiban therapy, and is safe.     

冠状动脉内应用维拉帕米对急性心肌梗死急诊介入治疗后冠状动脉灌注、心肌灌注和临床预后的影响

目的探讨急性ST段抬高性心肌梗死（STEMI）急诊经皮冠状动脉介入治疗（PCI）时冠状动脉内应用维拉帕米对冠状动脉灌注、心肌灌注及临床预后的影响。方法本研究为前瞻性、随机、双盲、对照性临床研究。连续性入选99例STEMI拟行急诊PCI的患者,随机分为维拉帕米组与对照组。在支架释放后即刻,维拉帕米组在靶血管内注入维拉帕米200μg,对照组在靶血管内注入肝素生理盐水,比较两组PCI术前、术后和冠状动脉内注药后的冠状动脉灌注和心肌灌注的差别。冠状动脉灌注以心外膜TIMI血流（TFG）和校正的TIMI血流帧数计数（CTFC）来评价。心肌灌注以TIMI心肌灌注分级（TMPG）和心肌灌注显影（MBG）来评价。并比较两组在PCI术后1周心脏彩色超声结果、住院期间以及随访期间主要心脏不良事件（MACE）发生率上的差别。结果最终91例患者有完整资料,其中维拉帕米组47例,对照组44例,两组临床基本特征和造影特征相仿。维拉帕米组和对照组在术前和支架释放后即刻冠状动脉灌注和心肌灌注各指标差异均无统计学意义（P〉0.05）。冠状动脉内注入维拉帕米后,维拉帕米组的CTFC、TFG、MBG、TMPG均较对照组有显著改善,分别为CTFC：27.1±14.2比39.0±23.8,P=0.011;TFG≥2级：100%比90.9%,P=0.035;MBG≥2级：91.5%%比75.5%,P=0.034;TMPG≥2级：89.4%比72.7%,P=0.042。维拉帕米组和对照组PCI术后1周时左室射血分数（63.4%±8.2%比63.5%±10.3%,P=0.578）、院内MACE发生率（4.3%比9.1%,P=0.613）和3个月MACE发生率（23.9%比22.7%,P=0.894）差异均无统计学意义。结论STEMI患者急诊行PCI治疗时,冠状动脉内应用维拉帕米可显著改善冠状动脉灌注和心肌灌注水平,但未观察到其对急诊PCI术后心室重构和短期临床预后的显著影响。     

Correlation between electrical and mechanical properties of the left ventricle in patients with postinfarction ventricular tachycardia

BACKGROUND: Electroanatomical mapping allows differentiation between viable and scarred myocardium. Echocardiography is widely used to assess myocardial contractility. The relationship between electrophysiological and echocardiographic assessment of left ventricular function has not yet been well established. AIM: To correlate mechanical and electrical function of the left ventricle in patients with postinfarction ventricular tachycardia and to assess clinical, echocardiographic and angiographic parameters affecting regional electrical function. METHODS: In 32 patients (25 males, 64+/-9 years old) mean unipolar (UP) and bipolar (BP) voltages were obtained with electroanatomical mapping (CARTO system) for a 12-segment model and compared with segmental wall motion function scored as normal, hypokinetic and a- or dyskinetic. UP voltage in individual groups of segments was: 7.8+/-4.2 mV, 6.5+/-4.2 mV, 4.7+/-2.5 mV, p <0.01 and for BP voltage 2.1+/-1.5 mV, 1.9+/-1.9 mV, 1.1+/-1.0 mV, p < 0.01, respectively. Left ventricular ejection fraction < or =30%, end-diastolic diameter >56 mm, previous inferior or anterior myocardial infarction (MI), MI < or =5 years and open infarct-related artery were associated with lower voltage in normokinetic segments. CONCLUSIONS: Segments with advanced systolic dysfunction had significantly lower uni- and bipolar voltage than normo- and hypokinetic segments. However, preserved local electrical function could be found in a/dyskinetic regions. Left ventricular remodelling, time and location of MI and patency of infarct-related artery influenced voltage in normokinetic segments.     

Electrocardiographic factors playing a role in ischemic ventricular fibrillation in ST elevation myocardial infarction are related to the culprit artery.

BACKGROUND: Sudden cardiac death caused by ischemic ventricular fibrillation (VF) associated with ST elevation myocardial infarction (STEMI) is one of the most frequent causes of death. OBJECTIVE: We hypothesized that electrocardiographic (ECG) characteristics differ between STEMI patients with and without ischemic VF. METHODS: Fifty-five first STEMI patients with at least one 12-lead ECG recorded before ischemic VF were compared with 110 first STEMI patients without ischemic VF. Patients with bundle branch blocks or high-degree atrioventricular blocks with escape rhythms were not included. ECG measurements were performed manually after scanning the ECG with the most prominent ST deviation into a software environment and magnifying it 4 times. RESULTS: Mean age was 57 +/- 12 years, and 126 patients were male. No differences were present between the VF and control group regarding baseline, enzymatic, and angiographic data. In left circumflex artery and right coronary artery myocardial infarction, a longer QRS interval (109 +/- 23 ms vs. 91 +/- 16 ms, P = .02 and 107 +/- 24 ms vs. 93 +/- 19, P = .02) was present. In the latter the PR interval (211 +/- 64 ms vs. 160 +/- 36 ms, P <.001) and ST deviation score (3.6 +/- 1.0 mV vs. 1.7 +/- 1.5 mV, P <.001) were also increased. In the left anterior descending artery group no differences in conduction intervals and ST deviation score were present. CONCLUSION: Longer PR and QRS intervals in right coronary artery and left circumflex artery MI fit with the perfusion and activation pattern of the atrioventricular node and the ventricular myocardium. Myocardium perfused by the left anterior descending artery is activated earliest, hiding any intraventricular conduction delay within the QRS complex. Intramural slowed conduction could be a substrate for ischemic VF.