Risk of death and recurrent ventricular arrhythmias in survivors of cardiac arrest concurrent with acute myocardial infarction

Aims

Cardiac arrest (CA) is an indication for defibrillator (ICD) implantation unless it occurs in the context of an acute myocardial infarction (AMI). We investigated the ventricular arrhythmia (VA)-free survival of patients resuscitated from CA in the setting of AMI.

Methods

We reviewed a database of 1600 AMI and CA survivors from which 48 patients were identified as having concurrent CA and AMI (CA+AMI group). Those patients were matched by age, gender, race, and left ventricular ejection fraction (LVEF) to 96 patients with AMI but no CA (AMI group) and 48 patients with CA but no AMI (CA group).

Results

Patients and controls were followed for 3.9±3.2 years. Patients in the 3 groups had similar baseline characteristics (age 63±14 yrs, 78% men, 98% white, 53% with CAD, LVEF 33±14%). The 5-year VA-free survival was 67%, 92%, and 80% for the CA+AMI, AMI, and CA groups, respectively, p<0.001.

Conclusion

Patients with concurrent CA and AMI are at high risk of recurrent VA, with VA-free survival rates significantly worse than those of patients with AMI but no CA, and comparable to those of patients with CA outside the context of an AMI. Accordingly, these patients should be considered for ICD implantation.     

Procedural and long-term outcome of primary percutaneous coronary intervention in octogenarians

Background/objectives. To investigate the procedural and long-term outcome of primary percutaneous coronary intervention (PCI) in octogenarians with an acute myocardial infarction. Methods. We performed a retrospective analysis of all consecutive octogenarian patients (n=98) with an acute myocardial infarction treated with primary PCI in the Catharina Hospital in the year 2006. We compared procedural results and outcome with a matched control group composed of non-octogenarians undergoing primary PCI. Follow-up period was one year. Results. The initial success rate of PCI was similar in the two groups but short-term mortality was higher among the elderly patients: 30-day mortality 26.3 vs. 9.6%. Age-adjusted mortality between 30 days and one year was comparable in the two groups and similar to natural survival in the Netherlands. Octogenarians were less likely to have a normal left ventricular function during follow-up (48.3 vs. 66.7%). New York Heart Association (NYHA) class and recurrence rate of myocardial infarction was higher among octogenarians. Conclusion. Technical success rate during primary PCI was as good for octogenarians as in younger patients, but 30-day mortality, though acceptable, was higher among the elderly. After 30 days, age-adjusted mortality was comparable in both groups. (Neth Heart J 2010;18:129-34.)     

Early versus late ST-segment resolution and clinical outcomes after percutaneous coronary intervention for acute myocardial infarction

Background. Absence of complete ST-segment resolution (STR) after percutaneous coronary intervention (PCI) for ST-segment-elevation myocardial infarction (STEMI) is a determinant of mortality. Traditionally, STR is determined on the coronary care unit (CCU) 60 to 90 minutes after the initiation of reperfusion therapy. We studied the prognostic value of STR immediately after PCI. Methods. We analysed 223 consecutive patients with STEMI and successful PCI. Continuous ECG data were collected during PCI and at 30 minutes after arrival on the CCU (mean time 81±17 minutes after reflow of the culprit artery). Patients were divided into three groups: patients with complete STR immediately after PCI (‘early’), patients with complete and persistent STR at 30 minutes on the CCU, but not immediately after PCI (‘late’) and patients without STR. One-year follow-up was obtained for death and rehospitalisation for major adverse cardiac events. Cox proportional hazards regression was used to evaluate the association between STR and outcome. Results. Early STR occurred in 115 (52%) and late STR in 43 (19%) patients. Patients with early or late STR had a lower incidence of one-year cardiac death than those without STR (1.9 vs. 9.2%; p=0.02). In contrast, rehospitalisation occurred more frequently in patients with early or late STR (20.3 vs. 6.2%; p=0.009). As compared with patients without STR, early and late STR had a similar prognostic value (hazard ratios [95% confidence interval] for cardiac death 0.40 [0.08-2.03] and 0.25 [0.03-2.08]). Conclusions. We found no (major) change in prognostic value of STR during the 0 to 90 minutes time window after PCI. (Neth Heart J 2010;18:416-22.)     

Standardised pre-hospital care of acute myocardial infarction patients: MISSION! guidelines applied in practice

Background. To improve acute myocardial infarction (AMI) care in the region ‘Hollands-Midden’ (the Netherlands), a standardised guideline-based care program was developed (MISSION!). This study aimed to evaluate the outcome of the pre-hospital part of the MISSION! program and to study potential differences in pre-hospital care between four areas of residency. Methods. Time-to-treatment delays, AMI risk profile, cardiac enzymes, hospital stay, in-hospital mortality, and pre-AMI medication was evaluated in consecutive AMI patients (n=863, 61±13years, 75% male) transferred to the Leiden University Medical Center for primary percutaneous coronary intervention (PCI). Results. Median time interval between onset of symptoms and arrival at the catheterisation laboratory was 150 (interquartile range [IQR] 101-280) minutes. The alert of emergency services to arrival at the hospital time was 48 (IQR 40-60) minutes and the door-to-catheterisation laboratory time was 23 (IQR 13-42) minutes. Despite significant regional differences in ambulance transportation times no difference in total time from onset of symptoms to arrival at the catheterisation room was found. Peak troponin T was 3.33 (IQR 1.23-7.04) µg/l, hospital stay was 2 (IQR 2-3) days and in-hospital mortality was 2.3%. Twelve percent had 0 known risk factors, 30% had one risk factor, 45% two to three risk factors and 13% had four or more risk factors. No significant differences were observed for AMI risk profiles and medication pre-AMI. Conclusions. This study shows that a standardised regional AMI treatment protocol achieved optimal and uniformly distributed pre-hospital performance in the region ‘Hollands-Midden’, resulting in minimal time delays regardless of area of residence. Hospital stay was short and in-hospital mortality low. Of the patients, 88% had ≥1 modifiable risk factor. (Neth Heart J 2010;18:408-15.)     

维拉帕米对急性前壁心肌梗死行急诊PCI术患者再灌注室性心律失常的影响

目的:探讨经指引导管早期应用维拉帕米对急性前壁心肌梗死行急诊经皮冠状动脉介入治疗术(Percutaneous Coronary Intervention,PCI)患者再灌注室性心律失常的影响。方法:采用单中心、随机对照、前瞻性研究方法。选取2014年5月-2016年11月诊断为急性前壁心肌梗死并于我院行急诊PCI的患者,共纳入162例患者,按随机方法(随机数字表)分成2组,其中治疗组82例,对照组80例。治疗组患者在首次球囊扩张后早期经指引导管内给予维拉帕米(200μg),对照组患者则给予生理盐水。观察再灌注后室性心律失常发生率,PCI术后冠脉血流情况,心肌梗死相关血清指标(CK-MB,cTn I)的峰值,住院期间发生的主要不良心血管事件(MACE)。结果:维拉帕米治疗组患者再灌注心律室性失常及无复流的发生率显著低于生理盐水对照组(P0.05);维拉帕米治疗组患者cTnI和CK-MB峰值分别为(46.63±13.77)μg/L和(139.87±35.45)U/L,生理盐水组cTnI和CK-MB峰值为(54.36±12.59)μg/L和(158.34±40.18)U/L,两组比较,P均0.01。MACE事件两组间未见有统计学差异。结论:急性前壁心肌梗死患者急诊PCI术前经导管早期给予维拉帕米不但可显著减少无复流现象,还可显著减少再灌注后室性心律失常的发生,住院期间MACE事件的发生率无显著性差异。     

Significant narrowing of the circumflex artery leads to worse outcomes than right coronary artery narrowing in patients with anterior myocardial infarction treated invasively

Background

Occlusion of the circumflex artery (Cx) often does not present signs in the ECG. It can lead to delayed angiography during ST-elevation myocardial infarction (STEMI). The aim of this analysis was to determine if Cx narrowing is related to diverse outcomes in comparison with right coronary artery (RCA) stenosis in patients with STEMI, treated with percutaneous coronary intervention (PCI) of the left descending artery (LAD).

Methods and results

Inclusion criteria were as follows: first STEMI treated with PCI of the LAD and additional significant (≥ 70 %) Cx or RCA narrowing—two-vessel disease. A total of 234 consecutive patients with STEMI were included. Total mortality was estimated during long-term follow-up, at mean 639 (± 224) days after STEMI. Patients with Cx narrowing constituted 46 % (N = 108) of the study population, and patients with RCA narrowing amounted to 54 % (N = 126). Patients with narrowing of the Cx had worse long-term outcomes in terms of mortality than patients with RCA narrowing (22 vs. 11 %, p < 0.05, respectively). Multiple regression analysis showed independent risk factors for death during long-term follow-up such as: age, ejection fraction and Cx narrowing.

Conclusion

Significant Cx narrowing leads to worse outcomes than RCA narrowing in patients with STEMI treated with PCI of the LAD.     

高龄ST段抬高心肌梗死患者经皮冠状动脉介入术后的院内预后及其影响因素分析

目的:探讨高龄ST段抬高心肌梗死(STEMI)患者行直接经皮冠状动脉介入(PCI)术后住院期间的预后情况及其影响因素。方法:回顾性分析2009年1月至2013年12月因STEMI入住我院并行直接PCI的高龄患者(年龄≥75岁)的一般情况、既往史、入院情况、术中及术后情况、并发症等资料,总结分析该类患者住院期间的临床预后,并采用logistic回归模型对可能影响住院期间主要不良心脏事件(MACE)的危险因素进行分析。结果:研究共纳入127例患者,其中男性84例(66.14%),女性43例(33.86%),年龄79±3岁,住院时间13.07±7.80天,住院期间MACE的发生率为17.32%,其中死亡4例(3.15%)。单因素logistic回归分析显示入院时心功能(Killip分级)≥2级、完全性房室传导阻滞、窦性停搏与高龄STEMI患者直接PCI术后住院期间MACE的发生相关,具有统计学意义(P0.05)。而多因素logistic回归分析显示入院时心功能(Killip分级)和完全性房室传导阻滞是高龄STEMI患者住院期间MACE的危险因素。结论:高龄STEMI患者接受直接PCI治疗总体安全,影响其住院期间MACE的危险因素包括心功能不全和完全性房室传导阻滞。     

早期足量应用美托洛尔对急性心肌梗死疗效及安全性的研究

目的:研究早期足量应用美托洛尔对急性心肌梗死的疗效及安全性.方法:将40例AMI患者随机分为治疗组和对照组.治疗组静脉缓慢注射美托洛尔15mg后予关托洛尔150-200mg/d口服;对照组按常规剂量给予美托洛尔25-50mg/d口服.其它治疗相同,两组治疗4周.比较两组治疗后QTcd、心律失常发生的种类、心肌耗氧指数、梗死后心绞痛、梗死延展的发生率和心功能的变化.结果:治疗组QTcd、室性心律失常发生率、心肌耗氧指数、梗死后心绞痛和梗死延展的发生率均低于对照组(P<0.05).心功能两组无显著性差异.结论,AMI患者早期足量使用美托洛尔可以从多方面获益,安全性高.     

Genetic variants in post myocardial infarction patients presenting with electrical storm of unstable ventricular tachycardia

Electrical storm (ES) is a life threatening clinical situation. Though a few clinical pointers exist, the occurrence of ES in a patient with remote myocardial infarction (MI) is generally unpredictable. Genetic markers for this entity have not been studied. In the present study, we carried out genetic screening in patients with remote myocardial infarction presenting with ES by next generation sequencing and identified 25 rare variants in 19 genes predominantly in RYR2, SCN5A, KCNJ11, KCNE1 and KCNH2, CACNA1B, CACNA1C, CACNA1D and desmosomal genes - DSP and DSG2 that could potentially be implicated in electrical storm. These genes have been previously reported to be associated with inherited syndromes of Sudden Cardiac Death. The present study suggests that the genetic architecture in patients with remote MI and ES of unstable ventricular tachycardia may be similar to that of Ion channelopathies. Identification of these variants may identify post MI patients who are predisposed to develop electrical storm and help in risk stratification.     

冠脉内注射替罗非班不同给药方式对急性心肌梗死介入治疗术中血流异常的影响

目的：比较急性心肌梗死介入治疗中冠脉内常规给予以及必要时给予血小板膜糖蛋白（GP）Ⅱb／Ⅲa受体拮抗剂替罗非班两种给药方式对冠脉血流异常的影响,寻找较好的替罗非班用药方式。方法：入选九四医院2005年1月至2008年10月急性心肌梗死直接PCI患者58例,随机分成常规给药组（血管开通前所有患者冠状动脉内均注射替罗非班,n=30）与必要时给药组（血管开通后即时造影显示TIMI血流≤2级者冠脉内注射替罗非班,TIMI血流3级者不给药,n=28）,观察支架植入后30分钟TIMI血流、30天内主要不良心血管事件（MACE）、出血以及血小板减少情况。结果：必要给药组冠脉内给药可显著改善冠脉血流（TIMI3级给药前46．4％,给药后75％,P〈0．05）,常规给药组支架植入后30分钟TIMI3级获得率高于必要给药组（96．7％比75％,P〈0．05）,MACE、出血和血小板减少事件两组之间差异无统计学意义。结论：冠脉内给予替罗非班可有效降低急性心肌梗死PCI术中血流异常情况,血管开通前冠脉内常规给药方式优于必要时给药方式。     

Utility of cardiac imaging in patients with ventricular tachycardia

Ventricular tachycardia (VT) is a life-threatening arrhythmia that may be idiopathic or result from structural heart disease. Cardiac imaging is critical in the diagnostic workup and risk stratification of patients with VT. Data gained from cardiac imaging provides information on likely mechanisms and sites of origin, as well as risk of intervention. Pre-procedural imaging can be used to plan access route(s) and identify patients where post-procedural intensive care may be required. Integration of cardiac imaging into electroanatomical mapping systems during catheter ablation procedures can facilitate the optimal approach, reduce radiation dose, and may improve clinical outcomes. Intraprocedural imaging helps guide catheter position, target substrate, and identify complications early. This review summarises the contemporary imaging modalities used in patients with VT, and their uses both pre-procedurally and intra-procedurally.     

肌钙蛋白I水平检测对急诊房颤患者的临床意义

目的:探讨房颤患者急诊入院时检测肌钙蛋白I(Tn I)水平的临床作用及预测价值。方法:回顾性分析我院523例房颤患者的临床资料,将资料中数据进行统计学分析处理。患者分为三组:1组患者Tn I轻度升高;2组患者Tn I正常;3组患者未检测Tn I,分别就三组患者的基线特征以及就诊时的症状展开数据比较,并且单变量及多变量分析Tn I升高的预测因子。设置主要终点为1年内所有原因导致的死亡及心肌梗死(MI),患者从入院时起随访1年,记录期间的MI发生情况及死亡情况。结果:173例患者(33%)Tn I轻度升高(均值0.56 ng/m L),225例患者(43%)Tn I正常,125例患者(24%)未检测Tn I。住院期间1组患者(50%)的心功能检查异常明显高于组2和组3(28%和29%,P≤0.001),1组患者(22%)主要终点发生率明显高于2组(10%)和3组患者(15%)(P=0.002),有统计学意义。结论:肌钙蛋白I轻度升高与冠脉疾病(CAD)发生率增加及MI发生率增加有关,但对于总体死亡率无影响。     

B-type natriuretic peptide predicts new-onset atrial fibrillation in patients with ST-segment elevation myocardial infarction treated by primary percutaneous coronary intervention

The predictive value of B-type natriuretic peptide (BNP) with respect to the occurrence of new-onset atrial fibrillation (AF) in patients with ST-segment elevation myocardial infarction (STEMI) treated by primary percutaneous coronary intervention (PCI) is unknown. The aim of this study was to evaluate whether BNP has a predictive value for the occurrence of new-onset AF in patients with STEMI treated by primary PCI. In 180 patients with STEMI treated by primary PCI, BNP concentrations were measured 24h after chest pain onset. The Receiver Operating Characteristic analysis was performed to identify the most useful BNP cut-off level for the prediction of AF. The patients were divided into the two groups according to calculated cut-off level: high BNP group (BNP≥720 pg/mL, n=33) and low BNP group (BNP<720 pg/mL, n=147). The incidence of AF was 5.0%, and occurred more frequently in high BNP group (7/33, 21.2%) than in low BNP group (2/147, 1.4%), (p<0.001). Patients with high BNP were older (p=0.017), had more often anterior wall infarction (p=0.015), higher Killip class on admission (p=0.038), higher peak troponin I (p=0.002), lower left ventricular ejection fraction (p=0.029) than patients with low BNP. After multivariate adjustment, BNP was an independent predictor of AF (OR 3.70, 95% CI 1.40-9.77, p=0.008). BNP independently predicts the occurrence of new-onset AF in STEMI patients treated by primary PCI.     

Everolimus- and sirolimus-eluting stents in patients with and without ST-segment elevation myocardial infarction

Aims

Everolimus-eluting stents (EES) were superior to sirolimus-eluting stents (SES) in a dedicated myocardial infarction trial, a finding that was not observed in trials with low percentages of ST-elevation myocardial infarction (STEMI). Therefore, this study sought to investigate the influence of clinical presentation on outcome after EES and SES implantation.

Methods

A pooled population of 1602 randomised patients was formed from XAMI (acute MI trial) and APPENDIX-AMI (all-comer trial). Primary outcome was cardiac mortality, MI and target vessel revascularisation at 2 years. Secondary endpoints included definite/probable stent thrombosis (ST). Adjustment was done using Cox regression.

Results

In total, 902 EES and 700 SES patients were included, of which 44 % STEMI patients (EES 455; SES 257) and 56 % without STEMI (EES 447; SES 443). In the pooled population, EES and SES showed similar outcomes during follow-up. Moreover, no differences in the endpoints were observed after stratification according to presentation. Although a trend toward reduced early definite/probable ST was observed in EES compared with SES in STEMI patients, long-term ST rates were low and comparable.

Conclusions

EES and SES showed a similar outcome during 2-year follow-up, regardless of clinical presentation. Long-term safety was excellent for both devices, despite wide inclusion criteria and a large sub-population of STEMI patients.     

Prognostic value of rising mean platelet volume during hospitalization in patients with ST-segment elevation myocardial infarction treated with primary percutaneous coronary intervention

Background

The prognostic significance of changes in mean platelet volume (MPV) during hospitalization in ST segment elevation myocardial infarction (STEMI) patients underwent primary percutaneous coronary intervention (pPCI) has not been previously evaluated. The aim of this study was to determine the association of in-hospital changes in MPV and mortality in these patients.

Methods

Four hundred eighty consecutive STEMI patients were enrolled in this retrospective study. The patients were grouped as survivors (n?=?370) or non-survivors (n?=?110). MPV at admission, and at 48–72?h was evaluated. Change in MPV (MPV at 48–72?h minus MPV on admission) was defined as ΔMPV.

Results

At follow-up, long-term mortality was 23%. The non-survivors had a high ΔMPV than survivors (0.37 (??0.1–0.89) vs 0.79 (0.30–1.40) fL, p?<? 0.001). A high ΔMPV was an independent predictor of all cause mortality ((HR: 1.301 [1.070–1.582], p?=?0.008). Morever, for long-term mortality, the AUC of a multivariable model that included age, LVEF, Killip class, and history of stroke/TIA was 0.781 (95% CI:0.731–0.832, p?<? 0.001). When ΔMPV was added to a multivariable model, the AUC was 0.800 (95% CI: 0.750–0.848, z?=?2.256, difference p?=?0.0241, Fig. 1). Also, the addition of ΔMPV to a multivariable model was associated with a significant net reclassification improvement estimated at 24.5% (p?=?0.027) and an integrated discrimination improvement of 0.014 (p?=?0.0198).

Conclusions

Rising MPV during hospitalization in STEMI patients treated with pPCI was associated with long-term mortality.

     

急性心肌梗塞静脉溶栓后冠脉再通对左心室功能的影响

为进一步探讨静脉溶栓后冠脉再通对左室功能的有益影响,回顾性分析了88例静脉溶栓急性心肌梗塞(AMI)病人的二维超声心动图和部分病人的冠脉造影资料。根据溶栓再通标准分为再通组和未通组。在AMI发病后平均24.8±11.6天和22.9±24.4天分别进行了心超和冠造检查,观察室壁运动情况并测量左室射血分数(LVEF)。结果显示:未通组LVEF明显低于再通组,而室壁运动异常积分却显著高于再通组。左室扩大和室壁瘤的发生上,两组未发现有统计学差异。以上结果提示:AMI静脉溶栓使冠脉再通对左室功能和室壁运动障碍的改善起到有益的作用。     

Comparative study of ticagrelor and clopidogrel in therapeutic effect of acute myocardial infarction patients undergoing percutaneous coronary intervention

ObjectivesComparison of Ticagrelor vs clopidogrel in antiplatelet therapeutic effect of acute myocardial infarction patients undergoing percutaneous coronary intervention.MethodsThe study focused on 2000 acute myocardial infarction patients undergoing percutaneous coronary intervention (PCI) in our hospital from January 2013 to December 2015. To reduce the formation of acute stent thrombosis caused by clopidogrel resistance, we had two options, one was to double the dosage of clopidogrel, and the other was to substitute ticagrelor for clopidogrel. Based on random number table method, the 2000 patients were divided into experimental group and control group, each containing 1,000 patients. The patients in experimental group took 180 mg ticagrelor before PCI and 90 mg ticagrelor twice a day after PCI (Gu, 2016). In contrast, the patients control group took 600 mg clopidogrel before PCI and 150 mg clopidogrel once a day after PCI. Both groups were drawn 2.7 ml of fasting venous blood for platelet aggregation rate test before PCI and 2 h, 24 h, 7 days after PCI respectively. Turbidimetric method was used to measure the ADP-induced platelet aggregation rate and observe change of platelet aggregation rate and success rate. Incidence of liver and kidney malfunction and adverse actions were monitored. All patients accepted a 6-month of follow-up examination to record and compare incidences of major adverse cardiac and cerebrovascular events. The statistical results of both groups are analyzed and compared.ResultsThe platelet aggregation rate of experimental group before PCI and 2 h, 24 h, 7 days after PCI was 59.71% ± 7.24%, 59.20% ± 7.70%, 48.66% ± 7.80% and 43.39% ± 8.28%; The control group was 58.04% ± 5.61%, 56.25% ± 6.02%, 55.68% ± 3.14%, 53.94% ± 5.30%; Comparing the platelet aggregation rate of different time, P was less than 0.05. The success rate of platelet aggregation of experimental group and control group was 80.56% and 46.86% respectively. There were significant differences between the two groups and the P was less than .05. The postoperative serum creatinine level of experimental group was higher than that in the control group (P < .05). The incidence of adverse reactions in the experimental group was significantly lower than that of the control group. There were significant differences between the two groups and the difference was of statistical significance (P < .05). According to the 5-month follow-up examination: the incidence of major adverse cardiac and cerebrovascular events in experimental group was 2.60% (52/2000) ,while the control group was 13.00% (260/2000) . There were significant differences between the two groups and the difference was of statistical significance (P < .05).ConclusionsCompared with clopidogrel, ticagrelor can achieve better n antiplatelet effect for patients with acute myocardial infarction undergoing percutaneous coronary intervention (PCI). It can effectively reduce the incidence of postoperative adverse cardiac and cerebrovascular events and control the rate of adverse reactions within the acceptable range.     

Conditions mimicking acute ST-segment elevation myocardial infarction in patients referred for primary percutaneous coronary intervention

Background/Objectives. A rapid diagnosis of ST-segment elevation myocardial infarction (STEMI) is mandatory for optimal treatment. However, a small proportion of patients with suspected STEMI suffer from other conditions. Although case reports have described these conditions, a contemporary systematic analysis is lacking. We report the incidence, clinical characteristics and outcome of patients with suspected STEMI referred for primary percutaneous coronary intervention (PCI) with a final diagnosis other than STEMI. Methods. From January 2004 to July 2005, 820 consecutive patients were included with suspected STEMI who were referred for primary PCI to a university medical centre, based on a predefined protocol. Clinical characteristics, final diagnosis and outcome were obtained from patient charts and databases. Results. In 19 patients (2.3%), a final diagnosis other than myocardial infarction was established: coronary aneurysm (n=1), (myo)pericarditis (n=5), cardiomyopathy (n=2), Brugada syndrome (n=1), aortic stenosis (n=1), aortic dissection (n=3), subarachnoidal haemorrhage (n=2), pneumonia (n=1), chronic obstructive pulmonary disease (n=1), mediastinal tumour (n=1), and peritonitis after recent abdominal surgery (n=1). These patients less often reported previous symptoms of angina (p<0.001), smoking (p<0.05) and a positive family history of cardiovascular diseases (p<0.05) than STEMI patients. Mortality at 30 days was 16%. Conclusion. A 2.3% incidence of conditions mimicking STEMI was found in patients referred for primary PCI. A high clinical suspicion of conditions mimicking STEMI remains necessary. (Neth Heart J 2008;16:325-31.)     

Effect of myocardial infarction and ischemia on induction of cardiac reentries and ventricular fibrillation

The present work is aimed at investigating the effects of myocardial infarction and ischemia on induction of ventricular fibrillation. Electrophysiologic effects of global and local ischemia (variation of the dispersion of refractory periods as well as conduction velocity) on initiation of reentry mechanisms was studied by means of computer simulations based on a cellular automata model of propagation of activation wave through a ventricular surface element. A local area of ischemia where effects of the dispersion of refractory periods are investigated is then simulated. This is made using a Gaussian distribution characterized by its mean and standard deviation. These simulations show that ischemia is capable of initiating reentry phenomena which propagate through the whole ventricle; they are responsible for ventricular fibrillation which causes sudden cardiac death, even when ischemia only involves limited parts of the myocardium. Statistical study of the probability of reentries as a function of both of the size of ischemic zones and the rate of dispersion of refractory periods shows that the latter parameter is of primary importance in triggering cardiac reentries.     

Proximal embolic protection in patients undergoing primary angioplasty for acute myocardial infarction (PREPARE): core lab adjudicated angiographic outcomes of a randomised controlled trial

Background. Patients with ST-segment elevation myocardial infarction (STEMI) treated with primary percutaneous coronary intervention (PCI) with the Proxis system (St. Jude Medical, St. Paul, MN, USA) achieved significantly better microvascular flow as measured by ST-segment resolution. However, no differences were observed in left ventricular ejection fraction or infarct size as obtained by cardiovascular magnetic resonance imaging. The goal of the present study was to evaluate the effect of combined proximal embolic protection and thrombus aspiration on core-lab adjudicated angiographic outcomes.Methods. In the PRoximal Embolic Protection in Acute myocardial infarction and Resolution of ST-Elevation (PREPARE) study, patients were randomised to primary PCI with the Proxis system (n=141) or primary PCI alone (n=143). An independent core laboratory re-evaluated all angiograms and adjudicated the angiographic outcomes and computerised quantitative blush evaluation (QuBE) value.Results. There were no significant differences in Thrombolysis In Myocardial Infarction (TIMI) flow grade, myocardial blush grade, or angiographic signs of distal embolisation among the two arms. QuBE values did not significantly differ between the Proxis-treated patients and control patients (15.1±5.4 vs. 15.8±5.5, respectively, p=0.34).Conclusion. Primary PCI with combined proximal embolic protection and thrombus aspiration in STEMI patients more frequently resulted in complete immediate ST resolution compared with control patients. However, there were no significant differences in core laboratory adjudicated angiographic outcomes. (Neth Heart J 2010;18:531–6.)