Acute myocardial infarction due to left main coronary artery occlusion

OBJECTIVE: Acute myocardial infarction due to left main coronary artery occlusion remains catastrophic and mostly fatal due to severe cardiogenic shock and arrhythmia. METHODS: We studied 13 patients undergoing coronary artery bypass grafting for acute myocardial infarction due to left main coronary artery occlusion to clarify the optimal management of these difficult patients. RESULTS: In-hospital mortality was 46.2% (6/13). Revascularization was achieved by catheter intervention followed by bypass surgery in 7, and bypass surgery alone in 6. Two bypass surgery patients without catheter intervention had collateral flow to the left coronary artery, with the right coronary artery dominant. The time from onset to recanalization in the survival group was significantly shorter than in the early death group. CONCLUSIONS: Emergency intervention to preserve left ventricular function or right coronary artery dominant and collateral blood flow to left coronary arteries is important for improving the prognosis of patients with acute myocardial infarction due to left main coronary artery occlusion. If residual left main coronary artery stenosis is significant or other proximal coronary stenosis exists after catheter intervention, early coronary bypass surgery may improve long-term survival.     

The effect of the left ventricular assist device on the myocardium during reperfusion after coronary artery occlusion

The effect of the left ventricular assist device (LVAD) during reperfusion after acute coronary occlusion was evaluated in a canine experimental model. The left circumflex artery was occluded for one hour, then reperfused for six hours immediately after removal of the occluder. Sixteen mongrel dogs were divided into the following two groups; a control group comprised of 7 dogs not given the LVAD support and another group comprised of 9 dogs (the LVAD group) assisted by LVAD for five hours during reperfusion. Throughout the study period, there was no significant difference in heart rate, aortic pressure or PA pressure between the two groups. However, LA pressure was significantly lower, while cardiac output, LV dp/dt, and LVSW were significantly higher in the LVAD group compared to the control group. Regional myocardial blood flow in the LCx area was significantly decreased after LCx occlusion in both groups but in the LVAD group, it recovered to the same level as before LCx occlusion after the beginning of reperfusion, while in the control group it remained significantly low throughout reperfusion. The LVAD group showed a positive myocardial lactate extraction in the early reperfusion period however, there was persistent lactate production in the control group. Thus, the unloading effect of LVAD during reperfusion after acute coronary artery occlusion improved regional myocardial blood flow and myocardial lactate metabolism and consequently, left ventricular function showed better recovery even after weaning from the LVAD support.     

Percutaneous revascularization in acute myocardial infarction due to left main stem occlusion

Following the encouraging results of trials testing the effect of primary percutaneous coronary intervention (PCI) more cases of left main arterial stenosis (LMS) as culprit lesions in acute myocardial infarction (AMI) are being handled. Not many cases of primary PCI on LMS have been published. We present 12 cases of primary PCI on LMS. Eighty-three percent of the patients presented with cardiogenic shock and only 42% were discharged alive. Due to the high rate of cardiogenic shock at presentation, PCI seems to be the treatment of choice, over coronary artery bypass grafting (CABG), although one might consider using PCI as a bridge over to CABG.     

Myocardial protection by a left ventricular assist device during reperfusion following acute coronary occlusion

To evaluate the effects of a left ventricular assist device (LVAD) during the reperfusion period following acute coronary occlusion, sixteen mongrel dog hearts were subjected to 1 hour’s occlusion of the circumflex coronary artery and then reperfused for 6 hours. In seven control dogs (control group), the hearts were reperfused without any support. In nine LVAD dogs (LVAD group), however, the left ventricles were supported by the application of a pneumatic driven diaphragm-type pump for 5 hours and then reperfused for another hour without any device. Triphenyltetrazolium chloride was used to determine the extent of infarction. The results showed a significant reduction in the area of infarct (AI) as a percentage of the area at risk (AR) in the LVAD group compared with the control group, the AI/AR being 22.3 per cent for the control groupversus 4.8 per cent for the LVAD group (p<0.05). The cardiac output was also significantly higher in the LVAD group compared with the control group. The per cent systolic shortening in the ischemic region of the LVAD group showed a significantly better recovery, being 75.8 per cent for the LVAD groupversus 24.4 per cent for the control group (p<0.01). It was concluded that the application of a LVAD during reperfusion after 1 hour’s coronary occlusion results in a significant reduction of infarct size and provides improvement in both regional and global cardiac function.     

Successful weaning from a left ventricular assist device after surgical repair of a left ventricular free wall rupture

We present a case of an insertion of a left ventricular assist device for severe cardiac failure after the repair of a left ventricular free wall rupture. A 72-year-old man was admitted with chest pain and unconsciousness, and required emergency surgical repair of a left ventricular free wall rupture under percutaneous cardiopulmonary support. Severe cardiac failure occurred postoperatively, and weaning from percutaneous cardiopulmonary support was impossible. We implanted a left ventricular assist device, and this could be removed at one week after implantation. The left ventricular assist device was very useful as a "bridge to recovery".     

Evaluation of Coronary artery bypass grafting in acute myocardial infarction

OBJECTIVES: We evaluated coronary artery bypass grafting (CABG) in acute myocardial infarction (AMI) within 14 days of onset. METHODS: Of 1,450 patients undergoing isolated CABG in the last 12 years we retrospectively analyzed operative risk factors and studied the use of CABG in treating AMI in 66 undergoing surgery during the AMI phase. We divided them into 2 groups: Group D (deceased: n = 8) and Group S (survivors: n = 58). RESULTS: Total operative mortality was 12.1% (8/66). Univariate analysis showed the following preoperative parameters to be significant in Group D: diabetes mellitus, cardiogenic shock, shortness of the interval between AMI onset and surgery, mean peak creatine phosphokinase-MB, AMI of the left main trunk, and failed recanalization of the infarcted artery. Multivariate analysis showed diabetes mellitus, cardiogenic shock, and AMI of the left main trunk as independent risk factors for hospital mortality. Intra-operative parameters between groups showed no statistical difference. Mortality in patients who did not suffer cardiogenic shock was zero. CONCLUSION: Maintenance of hemodynamics in the early phase is vital in treating AMI. The most important element in surgical intervention is revascularization of main branches. We concluded that CABG in AMI involves relatively low risk.     

Right ventricular myocardial infarction and late cardiac tamponade due to right coronary artery aneurysm —A case report—

Coronary artery aneurysm is a relatively rare disease, which may cuase angina, myocardial infarction, or sudeen unexpected death due to thrombosis, emboliozation or rupture. This report describes a case of a 46 year old male who suffered an inferior myocardial infarction with right ventricular involvement, third degree atrioventricular block, cardiogenic shock and late cardiac tamponade, all caused by a right coronary artery aneurysm. He was successfully treated with emergency coronary artery bypass grafting. A review of the literature is also given to emphasize the importance of prompt recognition and correct management of the coronary artery aneurysm.     

影像学诊断先天性左冠状动脉主干闭锁

目的探讨影像学诊断先天性左冠状动脉主干闭锁(LMCAA)的可行性。方法回顾性分析6例LMCAA患者,男3例、女3例,1例成人、5例婴幼儿。6例均接受超声心动图、多排螺旋CT(MDCT)及心血管造影检查。结果 1例超声提示左冠状动脉内径偏细,起源显示欠清晰,不除外左冠状动脉异常起源于肺动脉;1例超声提示左冠状动脉近段发育细,似壁内走行、开口狭窄;另4例超声仅提示二尖瓣脱垂并大量反流,冠状动脉未探及异常。5例经MDCT明确诊断为左冠状动脉主干闭锁,1例不除外左冠状动脉主干开口重度狭窄或闭锁。6例经心血管造影检查均明确诊断为LMCAA。结论 LMCAA属罕见先天性心脏病,超声可提示该病;CT对多数患者可明确诊断;心血管造影检查是诊断LMCAA的金标准。     

Comparison of left ventricular unloading strategies on venoarterial extracorporeal life support

OBJECTIVESOur goal was to compare the haemodynamic effects of different mechanical left ventricular (LV) unloading strategies and clinical outcomes in patients with refractory cardiogenic shock supported with venoarterial extracorporeal membrane oxygenation (VA-ECMO).Open in a separate windowMETHODSA total of 448 patients supported with VA-ECMO for refractory cardiogenic shock between 1 March 2015 and 31 January 2020 were included and analysed in a single-centre, retrospective case–control study. Fifty-three patients (11.8%) on VA-ECMO required LV unloading. Percutaneous balloon atrial septostomy (PBAS), intra-aortic balloon pump (IABP) and transapical LV vent (TALVV) strategies were compared with regards to the composite rate of death, procedure-related complications and neurological complications. The secondary outcomes were reduced pulmonary capillary wedge pressure, pulmonary artery pressure, central venous pressure, left atrial diameter and resolution of pulmonary oedema on a chest X-ray within 48 h.RESULTSNo death related to the LV unloading procedure was detected. Reduction in pulmonary capillary wedge pressure was highest with the TALVV technique (17.2 ± 2.1 mmHg; P < 0.001) and was higher in the PBAS than in the IABP group; the difference was significant (9.6 ± 2.5 and 3.9 ± 1.3, respectively; P = 0.001). Reduction in central venous pressure with TALVV was highest with the other procedures (7.4 ± 1.1 mmHg; P < 0.001). However, procedure-related complications were significantly higher with TALVV compared to the PBAS and IABP groups (50% vs 17.6% and 10%, respectively; P = 0.015). We observed no significant differences in mortality or neurological complications between the groups.CONCLUSIONSOur results suggest that TALVV was the most effective method for LV unloading compared with PBAS and IABP for VA-ECMO support but was associated with complications. Efficient LV unloading may not improve survival.     

Prediction of acute kidney injury after left ventricular assist device implantation: Evaluation of clinical risk scores

Acute kidney injury (AKI) is frequent in patients scheduled for implantation of a left ventricular assist device (LVAD) and associated with increased mortality. Although several risk models for the prediction of postoperative renal replacement therapy (RRT) have been developed for cardiothoracic patients, none of these scoring systems have been validated in LVAD patients. A retrospective, single center analysis of all patients undergoing LVAD implantation between September 2013 and July 2016 was performed. Primary outcome was AKI requiring RRT within 14 days after surgery. The predictive capacity of the Cleveland Clinic Score (CCS), the Society of Thoracic Surgeons Score (STS), and the Simplified Renal Index Score (SRI) were evaluated. 76 patients underwent LVAD implantation, 19 patients were excluded due to preoperative RRT. RRT was associated with a prolonged ventilation time, length of stay on the ICU and 180 day mortality (14(60.9%) vs 6(17.6%), P < .01). Whereas the Thakar Score (7.43 ± 1.75 vs 6.44 ± 1.44, P = .02) and the Mehta Score (28.12 ± 15.08 vs 21.53 ± 5.43, P = .02) were significantly higher in patients with RRT than in those without RRT, the SRI did not differ between these groups (3.96 ± 1.15 vs 3.44 ± 1.05, P = .08). Using ROC analyses, CCS, STS, and SRI showed moderate predictive capacity for RRT with an AUC of 0.661 ± 0.073 (P = .040), 0.637 ± 0.079 (P = .792), and 0.618 ± 0.075 (P = .764), respectively, with comparable accuracy in the Delong test. Using univariate logistic regression analysis, only the De Ritis Ratio (OR 2.67, P = .034) and MELD (OR 1.11, P = .028) were identified as predictors of postoperative RRT. Risk scores which are predictive in general cardiac surgery cannot predict RRT in patients after LVAD implantation. Therefore, it seems to be necessary to develop a specific risk score for this patient population.     

The influence of coronary artery bypass grafting to totally occluded coronary arteries on the left ventricular contractility

Sixteen patients underwent 16 coronary artery bypass grafts (CABG) to totally occluded coronary arteries (TOCA), including 12 left anterior descending coronary arteries (LAD) and 4 right coronary arteries (RCA). Of these 16 CABGs, 2 of the RCA grafts became obstructed postoperatively and the remaining 14 patients with patent grafts were divided into the two following groups: 8 with previous infarcts in the region perfused by the TOCA (Group I) and 6 with no previous infarcts (Group II). The left ventricular (LV) ejection fraction and the mean verocity of circumferential fiber shortening significantly increased postoperatively in both groups and the PLVSP/LVESV significantly increased postoperatively in Group II. The LV segmental wall motion (SWM) in the region of TOCA significantly increased postoperatively in both groups. In 5 of the Group I patients, whose anterior and apical SWM was less than the lowest value of the normal subjects, the anterior and apical SWM significantly increased postoperatively. We thus concluded that CABG to totally occluded LAD results in an excellent graft patency rate, a significant improvement of SWM in the region of the TOCA and global LV contractility, even in patients with severe segmental dysfunction due to previous infarcts.     

Right coronary artery dissection and acute infarction due to blunt trauma: Report of a case

(Received for publication on Apr. 17, 1997; accepted on Nov. 6, 1997)     

Outcome and selection of revascularization strategy in left main coronary artery stenosis

Objectives. To investigate clinical outcome in unselected real-life patients with unprotected left main coronary artery (ULMCA) stenosis and determine factors associated with selection of revascularization strategy. Design. Consecutive patients with ULMCA stenosis at our institution in 2009–2013 (n?=?308) were retrospectively analyzed with propensity score adjusted Cox proportional hazards models for outcome. Baseline characteristics in relation to selection of revascularization strategy were analyzed with multivariate logistic regression. Results. Patients that underwent PCI (n?=?94) had a higher risk of major adverse cardiac and cerebrovascular events (MACCE; adjusted HR 2.13 [95% CI 1.08–4.19]) than patients that had CABG surgery but there was no difference in the combination of death and MI (adjusted HR 1.17 [95% CI 0.50–2.75]). Later year of index angiography, age, Euroscore II and angiographer favoring PCI was associated with PCI as revascularization strategy. Higher SYNTAX score, higher systolic blood pressure and angiographer favoring CABG was associated with CABG. Conclusions. In consecutive patients with ULMCA stenosis PCI is associated with higher MACCE rates than CABG but there is no difference in death and MI. Later year of index angiography, higher age, lower systolic blood pressure, higher predicted per-procedural surgical risk, less complex coronary anatomy and angiographer favoring PCI increased the probability of revascularization with PCI instead of CABG.     

Grade of left main coronary artery stenosis does not influence long-term mortality after coronary artery bypass surgery

Objective. To assess if grade of left main coronary artery (LMCA) stenosis influences early or long-term mortality after coronary artery bypass grafting (CABG). Design. Among all 1 384 patients with LMCA stenosis at Karolinska Hospital, Stockholm, Sweden during 1990–1999, 131 deaths occurred within 5 years of surgery (cases). Matched controls (n=146) were randomly selected from all surviving LMCA patients taking gender, age and year of surgery into account. Angiographies were classified for grade of LMCA stenosis before the operation. Results. High-grade LMCA stenosis was equally common among cases and controls (50 vs. 45%). The odds ratio (OR) of mortality 5 years after the operation in patients with high-grade versus low-grade LMCA stenosis based on the matched pairs was 1.2 (95% confidence interval (CI) 0.7–2.0) and after multivariable adjustment using information on all subjects the OR was 1.0 (95% CI 0.6–1.7). For early and one year mortality similar odds ratios were observed but with wide confidence intervals. Conclusions. Grade of LMCA stenosis does not appear to influence early or long-term mortality after CABG performed during 1990–1999.     

Patterns of coronary artery ectasia and short-term outcome in acute myocardial infarction

Objective. To assess the relationship between hematological inflammatory signs, cardiovascular risk (CV) factors and prognosis in patients presenting with acute myocardial infarction (AMI) and coronary artery ectasia (CAE). Design. We investigated 3321 AMI patients who required urgent primary percutaneous intervention in two centres in the United Kingdom between January 2009 and August 2012. Thirty patients with CAE were compared with 60 age- and gender-matched controls. Blood was collected within 2 h of the onset of chest pain. CV risk factors were assessed from the records. Major acute cardiac events and/or mortality (MACE) over 2 years were documented. Results. CAE occurred in 2.7% and more often affected the right (RCA) (p = 0.001) and left circumflex artery (LCx) (0.0001). Culprit lesions were more frequently related to atherosclerosis in non-CAE patients (p = 0.001). Yet, CV risk factors failed to differentiate between the groups, except diabetes, which was less frequent in CAE (p = 0.02). CRP was higher in CAE (p = 0.006), whereas total leucocyte, neutrophil counts and neutrophil/lymphocyte ratio (N/L ratio) were lower (p = 0.002, 0.002 and 0.032, respectively) than among non-CAE. This also was the case in diffuse versus localised CAE (p = 0.02, 0.008 and 0.03, respectively). The MACE incidence did not differ between CAE and non-CAE (p = 0.083) patients, and clinical management and MACE were unrelated to the inflammatory markers. Conclusion. In AMI, patients with CAE commonly have aneurysmal changes in RCA and LCx, and their inflammatory responses differ from those with non-CAE. These differences did not have prognostic relevance, and do not suggest different management.     

Outcomes of congenital heart surgery patients after extracorporeal life support at Texas Children's Hospital

The objective of this study was to investigate the outcomes of children with heart failure of various etiologies requiring temporary use of currently available technology in the U.S.A. after extracorporeal life support (ECLS) [left ventricular assist device (LVAD) or extracorporeal membrane oxygenation (ECMO)] at Texas Children's Hospital. Between July of 1995 and October of 2002, 2847 patients underwent congenital heart surgical repairs with the aid of cardiopulmonary bypass at Texas Children's Hospital. During this period, 17 patients required chronic mechanical circulatory assistance with Biomedicus centrifugal pump (n=8) or Thoratec LVAD (n=4), and ECMO (n=5). Six out of 17 patients required ECLS for postcardiotomy heart failure. Seven of the 17 patients had congenital heart disease, six had cardiomyopathy, three had late acute rejection following heart transplantation, and one had myocardial infarction. Twelve patients survived and five patients expired. Six of 12 survivors recovered sufficient cardiac function to allow device removal; and the remaining six patients underwent heart transplantation. Three out of five deaths were ECMO patients. The need for ECLS following repair of congenital heart disease is extremely rare in our institution. The requirement for the use of ECMO confers a significantly higher mortality presumably because of associated combined cardiopulmonary failure. Congenital heart disease appears to be associated with significantly higher mortality.