Salbutamol in cardiogenic shock complicating acute myocardial infarction.

Intravenous salbutamol (13 microgram/min) has been given to 31 patients with cardiogenic shock complicating acute myocardial infarction. Haemodynamic measurements were made in nine of these patients. Salbutamol increased cardiac index by 41 per cent from 1.25 +/- 0.06 l/min per m2 to 1.76 +/- 0.19 l/min per m2 and decreased systemic vascular resistance by 16 per cent from 26.2 +/- 1.9 units to 21.9 +/- 2.1 units. Heart rate rose by 13 per cent from 95 +/- 4.5 beats/min to 106 +/- 6.0 beats/min. Pulmonary artery end-diastolic pressure fell from 20.6 +/- 1.7 mmHg to 16.9+/- 1.9 mmHg. Of the 31 patients, eight survived to leave hospital (27%). Five of the survivors had initial low heart rates and in these patients the clinical improvement was probably attributable to the positive chronotropic action of salbutamol. In the remaining three survivors clinical improvement was probably a result of salbutamol mediated afterload reduction. Salbutamol may be useful in the treatment of cardiogenic shock and pump failure complicating acute myocardial infarction.     

Safe Exchange of a Transfemoral Impella Pump

Mechanical circulatory support with the Impella pump is established in many centers treating patients with cardiogenic shock. While Impella pumps usually run very stable, it may still be possible that one needs to remove the pump for using the same vascular access for different reasons. Unfortunately, until now it had been nearly impossible to remove the pump while preserving arterial access without severe bleeding.Here we describe a prototypical approach of exchanging an Impella pump in a 47-year-old female supported with veno-arterial ECMO for cardiogenic shock from myocarditis. The dysfunctional Impella pump was safely removed and replaced by a new one through the same arterial access site. Continuation of active LV unloading resolved pulmonary edema, and the patient was finally bridged to ventricular assist device surgery with favorable outcome. In general, the described approach is applicable for virtually all large-bore devices with arterial access.     

Use of Impella Recover 2.5 left ventricular assist device in patients with cardiogenic shock or undergoing high-risk percutaneous coronary intervention procedures: experience of a high-volume center

AIM: Percutaneous coronary interventions are increasingly applied to high-risk patients. The availability of hemodynamic support devices offers a promising option to prevent and treat low-output syndrome in these patients. The aim of this study was to evaluate the feasibility, safety and efficacy of the Impella Recover' LP 2.5 left ventricular assist device in patients with cardiogenic shock or undergoing high-risk percutaneous coronary interventions. METHODS: Eleven patients presenting cardiogenic shock (N=6) or scheduled for high-risk percutaneous revascularization (N=5) were evaluated. The Impella pump was successfully implanted in all patients, except one. When implanted, the device was correctly positioned in the left ventricle and remained in a stable position. RESULTS: Bleedings occurred in 7 patients (5 of them presented cardiogenic shock), while renal failure and severe thrombocytopenia were observed in 4 and 1 patients respectively, all with cardiogenic shock. During high-risk procedures, the Impella pump succeeded in obtaining hemodynamic stability, while in only two patients with cardiogenic shock the device determined a significant improvement of hemodynamic variables. All elective patients and two patients with cardiogenic shock were discharged from the hospital and were still alive at 30-day follow-up. CONCLUSION: These data, although preliminary due to the limited sample size, demonstrated the feasibility, safety and efficacy of the Impella Recover(R) LP 2.5 during high-risk percutaneous procedures, even though the benefits of prophylactic deployment of such a system have to be further investigated. The use of Impella Recover(R) LP 2.5 in patients with cardiogenic shock is feasible and safe, however it maybe insufficient in reversing an advanced cardiogenic shock which, probably, has to be treated with more powerful left ventricular assist devices.     

Atrial natriuretic factor in cardiogenic shock, in hypovolemic shock and in the bradycardia-hypotension syndrome following acute myocardial infarction

The aim of this paper was to study plasma atrial natriuretic factor, renin activity, aldosterone and antidiuretic hormone in low-output heart failure syndromes such as cardiogenic shock, hypovolemic shock and hypotension with bradycardia syndrome. A total of 30 patients were investigated: 10 with cardiogenic shock due to acute myocardial infarction of the anterior wall (systolic and diastolic blood pressure 56.0 +/- 3.7/40.5 +/- 2.0 mmHg; heart rate 119.7 +/- 1.2 beats/min; central venous pressure 16.2 +/- 0.6 cmH2O) (I group), 10 with hypovolemic shock induced by melena in peptic ulcer (systolic and diastolic blood pressure 74.5 +/- 1.5/57.5 +/- 1.7 mmHg; heart rate 111.0 +/- 1.4; central venous pressure 6.3 +/- 0.5 cmH2O) (II group), 10 with hypotension with bradycardia syndrome which occurred in patients during acute myocardial infarction of the inferior wall (systolic and diastolic blood pressure 71.9 +/- 2.0/58.0 +/- 2.6 mmHg; heart rate 52.0 +/- 2.2 beats/min; central venous pressure 4.6 +/- 0.4 cmH2O) (III group). Plasma atrial natriuretic factor values were measured using radioimmunoassay after chromatographic pre-extraction; plasma renin activity, aldosterone and antidiuretic hormone values were calculated using radioimmunoassay. Circulating atrial natriuretic factor was significantly (p less than 0.01) higher in patients with cardiogenic shock (102.4 +/- 7.4 pg/ml) than in healthy volunteers (8.4 +/- 0.3 pg/ml). In the former there was a positive correlation between atrial natriuretic factor and central venous pressure values. Atrial natriuretic factor and central venous pressure values in the IInd and IIIrd groups of patients were in the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)     

Percutaneous biventricular Impella support in therapy-refractory cardiogenic shock

Introduction

Percutaneous mechanical circulatory support systems have increasingly been adopted as a bail out strategy in patients with cardiogenic shock. Since studies showed mostly mixed results, however, the use of support systems remains a case by case decision.

LINCS: L-NAME (a NO synthase inhibitor) in the treatment of refractory cardiogenic shock: a prospective randomized study.

AIMS: To evaluate the effect of L-NAME (a nitric oxide synthase inhibitor) in the treatment of refractory cardiogenic shock. METHODS AND RESULTS: We enrolled 30 consecutive patients with refractory cardiogenic shock (systolic blood pressure that deteriorated progressively to <100 mmHg during an acute coronary syndrome despite maximal percutaneous coronary revascularization, intra aortic balloon pump, and IV dopamine, furosemide and fluids treatment for at least 1h, accompanied by signs of peripheral hypoperfusion). Patients were randomized to supportive care alone (n=15, control group) or to supportive care in addition to L-NAME (1mg/Kg bolus and 1mg/Kg/h continuous IV drip for 5h n=15). Death at one month was 27% in the L-NAME group vs. 67% in the control group (p=0.008). Unaugmented mean arterial blood pressure at 24 h from randomization was 86+/-20 mmHg in the L-NAME group vs. 66+/-13 mmHg in the control group (p=0.004). Urine output increased at 24h by 135+/-78 cc/h in the L-NAME group vs a decrease of 12+/-87 cc/h in the control group (p<0.001). Time on IABP and time on mechanical ventilation were significantly shorter in the L-NAME group. CONCLUSIONS: The results of the present study further support our previous observation that NO synthase inhibitors are beneficial in the treatment of patients with refractory cardiogenic shock.     

Initial experience with the Impella left ventricular assist device for postcardiotomy cardiogenic shock and unprotected left coronary artery angioplasty in patients with a low left ventricular ejection fraction

Low-output syndrome is one of the leading causes of death following open-heart surgery or high-risk angioplasty. Ventricular assist devices have been used to treat patients who suffer from postoperative cardiogenic shock despite use of an intraaortic balloon pump and maximum inotropic support. The Impella pump (Impella Cardiosystems AG, Aachen, Germany) is a newly introduced left ventricular assist device that has been shown to reduce infarct size and to accelerate recovery of stunned myocardium. We report our initial experience using the Impella device for the treatment of cardiogenic shock following cardiopulmonary bypass and for maintaining hemodynamic stability in high-surgical-risk patients undergoing unprotected left coronary artery angioplasty.     

Acute hemodynamic effects of hypertonic (7.5%) saline infusion in patients with cardiogenic shock due to right ventricular infarction.

The hemodynamic effects, after infusion of 4 ml/kg of hypertonic (7.5%) saline solution (HS), were evaluated in six patients (mean age = 56.6 years) with cardiogenic shock (CS) due to right ventricular infarction (RVI). Basal condition data (mean +/- SEM) were as follows: cardiac index (CI) = 1.9 +/- 0.1 1/min/m2, arterial pressure (AP) = 66.5 +/- 0.9 mmHg, and systemic vascular resistance (SVR) = 31.3 +/- 1.0 mmHg/1/min/m2. Five- and 240-minute post-HS infusion data (respectively) revealed: CI = 3.3 +/- 0.1* and 2.9 +/- 0.1* 1/min/m2, AP = 87.7 +/- 1.6* and 80.7 +/- 2.2* mmHg, and SVR = 22.5 +/- 0.6* and 24.5 +/- 1.1* mmHg/1/min/m2 (*P less than 0.05 compared to baseline values). These data suggest that small-volume infusion of HS induced an important acute and sustained hemodynamic improvement in these patients with CS due to RVI.     

Impella Versus Extracorporeal Membranous Oxygenation (ECMO) for Cardiogenic Shock: A Systematic Review and Meta-analysis

The use of mechanical circulatory support (MCS) in cardiogenic shock (CS) is increasing. We conducted a systematic review and meta-analysis to compare the outcomes of Impella use with extracorporeal membranous oxygenation (ECMO) support in patients with CS. We searched the Medline, EMBASE, Cochrane, and Clinicaltrials.gov databases for observational studies comparing Impella to ECMO in patients with CS. Risk ratios (RRs) for categorical variables and standardized mean differences (SMDs) for continuous variables were calculated with 95% confidence intervals (CIs) using a random-effects model. Twelve retrospective studies and one prospective study (Impella n=6652, ECMO n=1232) were identified. Impella use was associated with lower incidence of in-hospital mortality (RR 0.88 [95% CI 0.80-0.94], P=0.0004), stroke (RR 0.30 [0.21-0.42], P<0.00001), access-site bleeding (RR 0.50 [0.37-0.69], P<0.0001), major bleeding (RR 0.56 [0.39-0.80], P=0.002), and limb ischemia (RR 0.42 [0.27-0.65], P=0.0001). Baseline lactate levels were significantly lower in the Impella group (SMD -0.52 [-0.73- -0.31], P<0.00001). There was no significant difference in mortality at 6-12 months, MCS duration, need for MCS escalation, bridge-to-LVAD or heart transplant, and renal replacement therapy use between Impella and ECMO groups. In patients with CS, Impella device use was associated with lower in-hospital mortality, stroke, and device-related complications than ECMO. However, patients in the ECMO group had higher baseline lactate levels.     

Hemodynamic and oxygen transport variables in cardiogenic shock secondary to acute myocardial infarction, and response to treatment

There are few data on oxygen transport in cardiogenic shock after acute myocardial infarction. This prospective study examined oxygen transport variables in 19 such patients and assessed their responses to treatment. Femoral and pulmonary arterial catheters were inserted before any therapy except correction of hypoxemia by mechanical ventilation in 8 patients, defibrillation (3 patients) or pacing (5 patients). In 3 patients mean arterial pressure was greater than 80 mm Hg and cardiac index greater than 2.1 liters/min/m2 with normal mixed venous oxygen saturation despite simultaneous clinical shock. They recovered with no further treatment. Sixteen patients were treated with varying combinations of intravenous fluids and dobutamine (37 +/- 25 mu/kg/min) and 14 survived long enough for a second set of measurements to be completed. Mean heart rate increased from 83 +/- 22 to 101 +/- 20 beats/min and mean cardiac index from 1.4 +/- 0.5 to 2.5 +/- 0.4 liters/min/m2 (p less than 0.001). Oxygen consumption (VO2) was maintained even when oxygen delivery (DO2) was less than 330 ml/min/m2. After treatment DO2 increased from 230 +/- 69 to 397 +/- 60 ml/min/m2 (p less than 0.001) and VO2 from 103 +/- 31 to 124 +/- 27 ml/min/m2 (p less than 0.05). Mean mixed venous oxygen saturation increased from 54 +/- 16 to 69 +/- 8% (p less than 0.001) and mean oxygen extraction ratio decreased from 48 +/- 16 to 31 +/- 6% (p less than 0.001). There was no correlation between cuff systolic blood pressure and mean arterial pressure before or after resuscitation. Thirteen patients survived to hospital discharge. When cardiogenic shock responds to treatment, large increases in DO2 lead to small increases in VO2 but large increases in mixed venous oxygen saturation, reflecting improved tissue oxygen availability.     

Administration of enoximone in cardiogenic shock

Thirteen patients in severe cardiogenic shock, persisting despite the use of adrenergic agents, were treated with enoximone, a recently available phosphodiesterase inhibitor. Cardiogenic shock was characterized by low cardiac output (less than 2.5 liter.min-1.m-2), elevated pulmonary artery balloon-occluded pressure (greater than or equal to 15 mm Hg), decreased urine output (less than 20 ml.hour-1) and increased blood lactate (greater than or equal to 2.0 mEq.liter-1). Ten patients were mechanically ventilated. A short-term intravenous infusion of 0.5 mg.kg-1 in 20 minutes of enoximone resulted in significant increases in cardiac index (from 1.8 +/- 0.3 to 2.9 +/- 0.3 liter.min-1.m-2, p less than 0.001) and stroke index (from 17.8 +/- 3.3 to 21.9 +/- 5.1 ml.m-2, p less than 0.001) and significant decrease in pulmonary artery balloon-occluded pressure (from 21.7 +/- 5.8 to 19.8 +/- 6.0 mm Hg, p less than 0.01) without a consistent change in mean arterial pressure (from 79 +/- 8 to 76 +/- 9 mm Hg, difference not significant). Enoximone administration decreased arterial oxygen tension (from 108 +/- 42 to 94 +/- 36 mm Hg, p less than 0.01) and increased venous admixture (from 12.8 +/- 6.5 to 16.0 +/- 8.0%, p less than 0.01). In 8 patients, a second infusion of 0.5 mg.kg-1 immediately thereafter amplified these changes. All patients but one survived the episode of cardiogenic shock and 5 patients left the hospital alive. These results indicate that the addition of enoximone to adrenergic agents in the treatment of cardiogenic shock can markedly increase cardiac output and stroke volume without substantial effects on arterial pressure.     

Impella support following emergency percutaneous balloon aortic valvuloplasty in patients with severe aortic valve stenosis and cardiogenic shock

BackgroundTo investigate the feasibility and outcomes of Impella 2.5 support in patients with severe aortic valve stenosis (AS) and cardiogenic shock (CS), who underwent emergency percutaneous balloon aortic valvuloplasty (BAV) with or without percutaneous coronary intervention (PCI).Methods and resultsWe retrospectively analyzed a consecutive series of patients with severe AS and CS who underwent Impella 2.5 support following emergency BAV with or without subsequent PCI. Outcome data included 30-day outcomes, periprocedural as well as throughout the circulatory support period complications. Eight patients with severe AS and CS were identified. Impella 2.5 implantation was successful following emergency BAV in all patients attempted. Additional PCI was performed in four patients. No periprocedural deaths or periprocedural neurologic events occurred. Mean procedure time was 125.9 min (range 64–210 min). Mortality at 30 days was 50%.ConclusionsImpella 2.5 can be used as hemodynamic support in patients with severe AS and CS following emergency percutaneous BAV and may help to improve tolerability of PCI in these high-risk patients.     

Left main coronary artery transradial rescue percutaneous coronary intervention for acute myocardial infarction complicated by cardiogenic shock with Impella ventricular mechanical support

Mechanical ventricular assist support and especially Impella device that is implanted via femoral access are considered a cornerstone in the therapeutic arsenal of the management of cardiogenic shock. Indeed, the potent antithrombotic agents administered during acute coronary syndromes constitute potential bleeding risk factors. Transradial interventions are nowadays widely used in ST-elevation myocardial infarction patients. However, some operators feel uncomfortable with the transradial approach when facing cardiogenic shock. We report a case of transradial rescue percutaneous intervention for cardiogenic shock in a young man with support of an Impella device via femoral access.     

Usefulness of Impella support in different clinical settings in cardiogenic shock

BACKGROUNDThe Impella pump has emerged as a promising tool in patients with cardiogenic shock (CS). Despite its attractive properties, there are scarce data on the specific clinical setting and the potential role of Impella devices in CS patients from routine clinical practice.METHODSThis is an observational, retrospective, single center, cohort study. All consecutive patients with diagnosis of CS and undergoing support with Impella 2.5^®, Impella CP^® or Impella 5.0^® from April 2015 to December 2020 were included. Baseline characteristics, management and outcomes were assessed according to CS severity, age and cause of CS. Main outcome measured was in-hospital mortality. RESULTSA total of 50 patients were included (median age: 59.3 ± 10 years). The most common cause of CS was acute coronary syndrome (ACS) (68%), followed by decompensation of previous cardiomyopathy (22%). A total of 13 patients (26%) had profound CS. Most patients (54%) improved pulmonary congestion at 48 h after Impella support. A total of 19 patients (38%) presented significant bleeding. In-hospital mortality was 42%. Among patients with profound CS (n = 13), five patients were previously supported with venoarterial extracorporeal membrane oxygenation. A total of eight patients (61.5%) died during the admission, and no patient achieved ventricular recovery. Older patients (≥ 67 years, n = 10) had more comorbidities and the highest mortality (70%). Among patients with ACS (n = 34), 35.3% of patients had profound CS; and in most cases (52.9%), Impella support was performed as a bridge to recovery. In contrast, only one patient from the decompensated cardiomyopathy group (n = 11) presented with profound CS. In 90.9% of these cases, Impella support was used as a bridge to cardiac transplantation. There were no cases of death. CONCLUSIONSIn this cohort of real-life CS patients, Impella devices were used in different settings, with different clinical profiles and management. Despite a significant rate of complications, mortality was acceptable and lower than those observed in other series.

Cardiogenic shock (CS) is a severe clinical condition which includes systemic hypotension and tissue hypoperfusion secondary to cardiac dysfunction with adequate or elevated filling pressures, and is commonly associated to a poor prognosis.^[1] Clinical practice guidelines^[2] recommend the use of inotropic drugs and vasopressors in order to maintain organ perfusion, early revascularization in cases due to acute coronary syndrome (ACS) and the use of mechanical circulatory support (MCS) in refractory cases.^[1,2] However, despite all these measures, mortality remains high in most series.^[3] The use of inotropic drugs and vasopressors increases myocardial oxygen consumption and proarrhythmic risk,^[4] and the use of MCS is associated with a high rate of complications^[5]. A better prognosis has been consistently observed in high volume centers with full availability of percutaneous coronary intervention (PCI), MCS, intensive cardiac care unit and especifically trained shock teams.^[6–10] Given the complexity of these patients, current guidelines recommend to organize the care of CS in different center networks according to the severity of patients.^[2]As stated before, MCS has emerged during the last years as a promising tool in critically ill patients with refractory CS. The ideal device in patients with CS requires an easy and quick insertion, the ability to unload left ventricle (LV) and increase cardiac output in order to restore tissue hypoperfusion. In this sense, the Impella devices (Abiomed Inc., Massachusetts, USA), consists of a transvalvular axial pump with femoral or axillary insertion that collects blood from the LV and ejects it directly into the ascending aorta.^[3] The Impella device provides MCS with an increase in mean arterial pressure, an increase in cardiac output and peak coronary blood flow while unloading LV, reducing end-diastolic volume, wall stress and oxygen consumption, thus favoring myocardial recovery.^[1,3] However, despite these attractive properties, there are scarce data on the specific clinical setting to use Impella devices and the efficacy and complications in its use in real world. Most publications report experience in high risk PCI or after acute myocardial infarction complicated by CS.^[11]Therefore, the aim of this study was to collect the results and complications of the use of Impella devices in a real world high complexity CS referral center over a five-year period in non-selected patients with CS of any etiology.     

心脏手术后ECMO治疗心源性休克

Background： Post-cardiotomy cardiogenic shock occasionally develops in patients who have undergone cardiac procedures. We report our experience using extracorporeal membrane oxygenation （ECMO） in adult patients with post -cardiotomy cardiogenic shock, and analyze the factors that affected outcomes for these ECMO patients.     

主动脉内球囊反搏治疗急性心肌梗塞并心源性休克56例疗效观察

目的:观察主动脉球囊反搏术(IABP)辅助治疗急性心肌梗塞(AMI)合并心源性休克的疗效。方法:对比分析56例AMI合并心源性休克患者应用IABP前后的血液动力学改变。结果:56例AMI合并心源性休克患者接受IABP治疗后血压[收缩压(113.3±17.5)mmHg∶(76.5±15.3)mmHg,舒张压(62.2±10.3)mmHg∶(31.1±10.2)mmHg]、心率[(82±14)次/min∶(118±27)次/min]、心指数[(3.91±1.12)L/min.m2∶(2.03±0.20)L/min.m2]较术前有显著改善(P均0.01)。结论:对急性心肌梗塞合并心源性休克患者行主动脉球囊反搏术可有效改善血流动力学状态,是有效的辅助治疗手段。     

Effects of left ventricular unloading by Impella recover LP2.5 on coronary hemodynamics.

OBJECTIVES: We studied the effects of LV unloading by the Impella on coronary hemodynamics by simultaneously measuring intracoronary pressure and flow and the derived parameters fractional flow reserve (FFR), coronary flow velocity reserve (CFVR), and coronary microvascular resistance (MR). BACKGROUND: Patients with compromised left ventricular (LV) function undergoing high-risk percutaneous coronary intervention (PCI) may benefit from LV unloading. Limited information is available on the effects of LV unloading on coronary hemodynamics. METHODS: Eleven patients (mean LV ejection fraction of 35 +/- 11%) underwent PCI during LV support by the LV unloading device (Impella Recover LP2.5). Intracoronary measurements were performed in a nonstenotic coronary artery after the PCI, before and after adenosine-induced hyperemia at four different support levels (0-2.5 L/min). RESULTS: Aortic and coronary pressure increased with increasing support levels, whereas FFR remained unchanged. Baseline flow velocity remained unchanged, while hyperemic flow velocity and CFVR increased significantly with increasing support levels (61 +/- 24 to 72 +/- 27 cm/sec, P = 0.001 and 1.88 +/- 0.52 to 2.34 +/- 0.63, P < 0.001 respectively). The difference between baseline MR and hyperemic MR significantly increased with increasing support levels (1.28 +/- 1.32 to 1.89 +/- 1.43 mm Hg cm(-1) sec, P = 0.005). CONCLUSIONS: Unloading of the LV by the Impella increased aortic and intracoronary pressure, hyperemic flow velocity and CFVR, and decreased MR. The Impella-induced increase in coronary flow, probably results from both an increased perfusion pressure and a decreased LV volume-related intramyocardial resistance.     

Impella assisted transradial coronary intervention in patients with acute coronary syndromes and cardiogenic shock

Operators may feel apprehension when considering the transradial approach in patients with cardiogenic shock due to concerns of the need for femoral access for mechanical support. There is however potential benefit of transradial approach in this setting by reducing bleeding complications in patients on potent anticoagulant and antiplatelet agents. We report three cases of patients with cardiogenic shock with successful transradial intervention (TRI) whilst using unilateral femoral access for Impella (ABIOMED, Danvers, MA) mechanical support. In two cases, the need for mechanical support was not clear at the beginning of the procedure, and in the third there was a clear need to combine femoral and radial access due to pre‐existing anatomic issues. Two patients required transfusion of red blood cells but otherwise there were no vascular access complications. © 2011 Wiley Periodicals, Inc.     

Myocardial perfusion grade and survival after percutaneous transluminal coronary angioplasty in patients with cardiogenic shock

We sought to evaluate myocardial reperfusion and its prognostic value after percutaneous transluminal coronary angioplasty (PTCA) in patients admitted for cardiogenic shock. Lack of myocardial reperfusion despite restored coronary flow affects the survival of patients with acute myocardial infarction (AMI). Myocardial blush grade (MBG) is an angiographic measure of myocardial perfusion. We assessed MBG in 41 consecutive patients admitted to our department within 12 hours from the onset of AMI and in cardiogenic shock. PTCA was successful in 83% of patients. Thrombolysis In Mycardial Infarction (TIMI) grade 3 flow was demonstrated in 22 patients (53%). MBG 2/3 was found in 14 patients (34%); among them, 12 had TIMI 3 flow. Compared with patients with MBG 2/3, those with MBG 0/1 were older (71 +/- 11 vs 57 +/- 13 years, p = 0.001), had a higher prevalence of diabetes (48% vs 14%, p = 0.04) and hypertension (63% vs 29%, p = 0.04), showed a trend toward longer ischemic time (6.1 +/- 2.4 vs 4.9 +/- 1.1), and had larger enzymatic infarct size (peak creatine kinase 7,690 +/- 3,516 vs 5,500 +/- 2,977 IU/L). Mortality was higher in patients with MBG 0/1 both in the hospital (81% vs 14%, p <0.001) and at follow-up (81% vs 29%, p = 0.001). After adjustment by multivariate analysis, MBG 0/1 (odds ratio 16, p = 0.01) and age (odds ratio 3.8/10 years, p = 0.04) were correlated with in-hospital mortality. MBG 2/3 was achieved in a few patients in cardiogenic shock after AMI who were treated with PTCA; this was a strong predictor of in-hospital survival. Also, risk stratification after mechanical revascularization should include assessment of restoration of myocardial reperfusion.     

Circulatory support for cardiogenic shock due to acute myocardial infarction: a Canadian experience.

BACKGROUND: Cardiogenic shock due to acute myocardial infarction (AMI) is associated with high mortality. Circulatory support devices may be used to assist these patients while they await cardiac transplantation. METHODS AND RESULTS: From 1986 to 1997, 25 patients in cardiogenic shock complicating AMI within 3.6+/-0.7 days of the event were supported with artificial hearts. Of the 25 patients, 21 were men with a mean age of 48.4 +/- 1.8 years. The age range was 26 to 62 years. Patients were considered for a device when the following criteria were met: cardiac index less than 1.8 L/min/m2, wedge pressure greater than 20 mmHg despite one or two inotropes and/or intra-aortic balloon support. They received either a CardioWest total artificial heart (n=13), a Thoratec biventricular assist device (n=6) or left ventricular assist device (LVAD) (n=6). Three patients were not considered transplant candidates and died while on the devices (two with multiorgan failure and one found to have a bronchogenic carcinoma after implant), with 22 undergoing cardiac transplantation within 8.6+/-2.2 days of device implant. Six patients died in hospital after the transplants (27.3% mortality). Complications included bleeding or tamponade in seven (28%), pneumonia in six (24%) and right ventricular failure in three LVAD patients (12%). Post-transplant actuarial one-, two- and five-year survival rates were 71.4%, 71.4% and 51%, respectively. CONCLUSIONS: Circulatory support devices offer a means to maintain organ perfusion in patients who develop cardiogenic shock due to AMI. Patients can then undergo transplantation with a reasonable expectation for survival when the alternative is death. Eventually the availability of permanent support devices may obviate the need for transplant in these patients.