Limitations of thrombolytic therapy for acute myocardial infarction complicated by congestive heart failure and cardiogenic shock

As many as one quarter of patients treated with thrombolytic therapy present with congestive heart failure or cardiogenic shock. Although thrombolytic therapy has been shown to limit infarct size, preserve left ventricular ejection fraction and decrease mortality in most subgroups of patients, no apparent benefit has been demonstrated in patients with clinical left ventricular dysfunction. The lack of correlation between ejection fraction and other measurements of left ventricular dysfunction such as exercise time, cardiac output, filling pressures, activation of the neurohumoral system and regional perfusion bed abnormalities may partly explain this paradox. Alternatively, lower perfusion rates, higher reocclusion rates, associated mechanical complications or completed infarction may explain these findings. Preliminary data indicate that emergency coronary angioplasty or bypass graft surgery improves survival in selected patients with cardiogenic shock. Because these findings suggest that restoration of infarct artery patency is especially important in patients with clinical left ventricular dysfunction, additional studies are needed in these patients to investigate the potential benefit that new thrombolytic strategies, inotropic or vasodilator agents or intraaortic balloon counterpulsation might offer by augmenting coronary blood flow and improving reperfusion rates. Currently, acute mechanical revascularization should be considered for patients who present with congestive heart failure associated with hypotension or tachycardia and for patients with cardiogenic shock.     

Procainamide pharmacokinetics in patients with acute myocardial infarction or congestive heart failure

Abnormal procainamide pharmacokinetics (prolonged half-life and decreased volume of distribution) and pharmacodynamics (decreased threshold for the suppression of premature ventricular complexes) have been suggested in patients with acute myocardial infarction or congestive heart failure, or both. To better define procainamide kinetics, 37 patients in the acute care setting received intravenous procainamide (25 mg/min, median dose 750 mg) with peak and hourly blood samples taken over 6 hours. Compared with the 10 control patients, the 12 patients with acute myocardial infarction and the 15 patients with congestive heart failure had normal procainamide pharmacokinetics with respect to half-life (2.3 +/- 1.0, 2.5 +/- 0.9 and 2.6 +/- 0.8 hours, respectively), volume of distribution (1.9 +/- 0.7, 1.8 +/- 0.4 and 1.8 +/- 0.5 liters/kg, respectively), clearance (11.3 +/- 7.5, 9.3 +/- 3.6 and 9.1 +/- 3.5 ml/min per kg, respectively) and unbound drug fraction (66 +/- 9, 66 +/- 9 and 69 +/- 4%, respectively). Low thresholds for greater than 85% premature ventricular complex suppression were confirmed in these patients (median 4.7 micrograms/ml in patients with acute myocardial infarction and 3.3 micrograms/ml in patients with congestive heart failure). Thus, differences in the response of premature ventricular complexes to procainamide reflect electropharmacologic differences dependent on clinical setting rather than pharmacokinetic abnormalities. Furthermore, the reduction of procainamide dosing in patients with acute myocardial infarction or congestive heart failure, based solely on prior kinetic data, may result in inappropriate antiarrhythmic therapy.     

Coronary stenting in acute myocardial infarction complicated with cardiogenic shock

AIM: To assess immediate and long-term results of urgent coronary stenting in patients with cardiogenic shock. MATERIAL AND METHODS: Twenty three patients (15 men, 8 women mean age 58-/+12 years) with myocardial infarction and cardiogenic shock treated with vasopressors and intraaortic balloon pumping (IABP). Culprit lesions were localized in left anterior descending and right coronary arteries in 16 and 7 cases, respectively. Prior to stenting 18 and 5 patients had TIMI grade 0 and 1 flow, respectively. RESULTS: Stents (n=26, Seaquence and Ephesos, length 12-28 mm, diameter 2-3.5 mm) were successfully implanted in all patients after balloon predilation. After stenting TIMI grade 3 flow was achieved in 15 patients, 8 patients had TIMI-2 flow without angiographic signs of dissection or residual stenosis. There were 4 inhospital deaths and 19 patients (83%) were discharged. One angioplasty and 2 coronary artery bypass grafting procedures because of restenosis and reocclusion were successfully performed during first 4 months of follow-up. CONCLUSION: Urgent stenting combined with IABP was effective method of treatment of cardiogenic shock with 83% inhospital survival and 61% freedom from repeat revascularization.     

Use of nitroglycerin in the treatment of acute heart failure and cardiogenic shock in patients with myocardial infarction

The effectiveness of nitroglycerin in the treatment of acute heart failure was investigated in 100 patients with myocardial infarction. It was found that nitroglycerin has marked advantages in comparison with cardiac glycosides both as regards its effectiveness and as regards the character of its action on the haemodynamics and the state of the periinfarction zone. In most patients (78%), a favourable effect was attained with intravenous nitroglycerin administration and with additional intake in the form of tablets. Clinical improvement was preceded by normalization of pulmonary artery pressure. Uninterrupted nitroglycerin administration was terminated after normalization and stabilization of haemodynamics. The results showed that with monitoring haemodynamics nitroglycerin can be administered also in haemodynamic disorders, which occur in the early period of cardiogenic shock.     

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.     

Relationship between plasma homocysteine levels and congestive heart failure in patients with acute myocardial infarction. Homocysteine and congestive heart failure

Heart failure after acute myocardial infarction (AMI) is an important factor in determining clinical outcome. We examined whether the plasma homocysteine level was a predictor of heart failure in patients with AMI. A series of 96 patients without renal failure who were admitted to our hospital because of AMI between January 2003 and December 2005 were assigned to two groups; a group with a high homocysteine level (group H: n = 48) and a group with a low homocysteine level (group L: n = 48) based on a median homocysteine level. Congestive heart failure was defined as Killip Class II or higher at the time of admission or the development of congestive heart failure after hospitalization. The mean brain natriuretic peptide (BNP) level at the time of admission in group H was higher than that of group L (175.3 pg/mL versus 89.9 pg/mL; P = 0.068). The incidence of heart failure in group H was significantly higher than that in group L (43.7% versus 12.5%; P < 0.001, log-rank test; hazard ratio: 2.92). Multivariate Cox regression analysis indicated that a high plasma homocysteine level of 10.8 μmol/L or higher was a risk factor for the development of heart failure (HR: 7.175, P < 0.01). The plasma homocysteine level in patients with AMI may be related to the development of heart failure.     

早期发生急性肾衰竭与急性心肌梗死后心源性休克患者预后的关系

目的了解急性心肌梗死后心源性休克患者早期发生急性肾衰竭与其预后的关系.方法回顾性分析解放军总医院1993～2003年间,因急性心肌梗死或冠心病心绞痛住院,并出现心源性休克的病例,以24h内是否出现急性肾衰竭为标准,比较其住院期间死亡率,并采用多元Logistic回归分析,评估早期发生急性肾衰竭对患者预后的影响.结果符合统计分析标准的患者共172例,其中51例(30%)于24h内出现急性肾衰竭.有无早期发生急性肾衰竭的患者,其住院死亡率分别为90%(46/51)和56%(68/121).逐步回归分析表明,早期发生急性肾衰竭是影响急性心肌梗死后心源性休克患者预后的独立因素(OR=6.7,95%可信限2.5～18;P＜0.001).结论急性心肌梗死后心源性休克患者,早期发生急性肾衰竭,与其住院死亡率显著相关,可作为判断患者不良预后的指标.     

Effect of propranolol after acute myocardial infarction in patients with congestive heart failure

The incidence of congestive heart failure was studied in the Beta Blocker Heart Attack Trial in which postmyocardial infarction patients between the ages of 30 and 69 years, with no contraindication to propranolol, were randomly assigned to receive placebo (n = 1921) or propranolol 180 or 240 mg daily (n = 1916) 5 to 21 days after admission to the hospital for the event. Survivors of acute myocardial infarction with compensated or mild congestive heart failure, including those on digitalis and diuretics, were included in the study. A history of congestive heart failure before randomization characterized 710 (18.5%) patients: 345 (18.0%) in the propranolol group and 365 (19.0%) in the placebo group. The incidence of definite congestive heart failure after randomization and during the study was 6.7% in both groups. In patients with a history of congestive heart failure before randomization, 51 of 345 (14.8%) in the propranolol group and 46 of 365 (12.6%) in the placebo group developed congestive heart failure during an average 25 month follow-up. In the patients with no history of congestive heart failure, 5% in the propranolol group developed congestive heart failure and 5.3% in the placebo group developed congestive heart failure. Baseline characteristics predictive of the occurrence of congestive heart failure by multivariate analyses included an increased cardiothoracic ratio, diabetes, increased heart rate, low baseline weight, prior myocardial infarction, age, and more than 10 ventricular premature beats per hour.(ABSTRACT TRUNCATED AT 250 WORDS)     

Predictors of mortality in patients with acute myocardial infarction and cardiogenic shock.

BACKGROUND: Although cardiogenic shock (CS) is the leading cause of death for acute myocardial infarction (AMI) patients, reliable predictive factors in the acute stage, such as cardiovascular peptides, have not yet been identified. METHODS AND RESULTS: In 42 consecutive AMI patients with CS on admission, successfully treated by primary percutaneous coronary intervention (PCI) within 12 h of onset, related factors including brain natriuretic peptide (BNP), atrial natriuretic peptide (ANP), renin, aldosterone, catecholamines, and adrenomedullin, were investigated 24 h from onset, as well as the 1-year mortality rates. During the 12-month follow-up period, 15 patients died from cardiovascular causes (group D). There were no significant differences in patient characteristics, angiographic findings, and left ventricular systolic function between group D subjects and the survivors (group S: n=27). Multivariate analysis identified high levels of adrenomedullin as an independent predictor of 1-year mortality (risk ratio: 6.42, 95% confidence interval, 1.49-43.31, p<0.05). CONCLUSIONS: The acute-phase plasma concentration of adrenomedullin may be a reliable predictor of mortality in patients with AMI complicated by CS and successfully treated by direct PCI, as may be BNP concentration, peak-creatine kinase value, and ventricular fibrillation.     

Prenalterol in cardiogenic shock following acute myocardial infarction

Eleven patients with cardiogenic shock following acute myocardial infarction (AMI) have been treated with prenalterol. This drug was administered in seven patients once dobutamine or dopamine proved to be ineffective or poorly effective, and it was the first inotropic drug employed in four patients. Therapeutic dose of intravenous infusion ranged from 2.2 to 18 μg/kg/min (mean dose: 7 μg/kg/min), and was maintained for 2 to 4 hours. Since two patients received the infusion on two different occasions, a total of 13 cases were considered for statistical analysis. Prenalterol produced an increase in cardiac index (p < 0.01), mean aortic pressure (p < 0.02), net work index (p < 0.01), net/stroke work index (p < 0.01), pressure rate product (p < 0.05), and myocardial perfusion gradient (p < 0.02). It decreased systemic (p < 0.02) and pulmonary (p < 0.01) vascular resistances, pulmonary artery (p < 0.01) and pulmonary capillary (p < 0.05) pressures. Heart rate and right atrial pressure were not significantly changed. The drug acted as a relatively selective inotropic agent without a chronotropic effect and with minimal peripheral actions. It was effective in seven patients and ineffective in four patients. Thus prenalterol appears to be a useful drug in cardiogenic shock and further studies are warranted.     

Impaired fasting glucose and cardiogenic shock in patients with acute myocardial infarction.

OBJECTIVES: In-hospital outcome after acute myocardial infarction (MI) has not yet been evaluated with regard to the new category of Impaired Fasting Glucose level (IFG) patients defined by the American Diabetes Association (ADA). METHODS: Nine hundred and ninety-nine patients with acute MI from the RICO survey were included in the study. Fasting blood glucose was measured after admission. Patients were grouped according to ADA definitions: Diabetes Mellitus (DM) (FG >/=7mmol/l or personal history of DM); IFG (FG 6.1 to 7mmol/l); NFG (normal FG <6.1mmol/l). RESULTS: Three hundred and eighty-one patients (38%) had DM, 145 (15%) IFG and 473 (47%) NFG. Mortality in the IFG group was twice that of the NFG group (8% vs 4%, P=0.049). A significant increase in cardiogenic shock (12% vs 6%, P=0.011) and ventricular arrhythmia (15% vs 9%, P=0.035) was observed in the IFG vs NFG group. IFG, after adjustment for confounding factors (age, sex, anterior location, and LVEF), was a strong independent predictive factor for cardiogenic shock (P=0.005). CONCLUSION: MI patients with IFG had an overall worse outcome, characterized by a higher risk of developing cardiogenic shock during their hospital stay.     

Predictors and importance of congestive heart failure in patients with acute inferior myocardial infarction

Inferior myocardial infarction (MI) is considered to have a more favorable prognosis than anterior wall MI but includes high risk groups with increased mortality and morbidity. It is well known that congestive heart failure (CHF) complicating acute MI has poor prognosis. In this study we assessed the clinical and prognostic significance of CHF and the predictive value of the baseline demographic and clinical variables for CHF in patients with acute inferior MI. A total of 350 patients with acute inferior MI were included. In group A there were 26 patients (7.4%) with CHF, and in group B there were 324 patients (92.6%) without this complication. Baseline clinical and demographic characteristics and in-hospital complications of the groups were assessed. In group A patients were older (67.6±9.5 vs 53.7±10.9 years, p<0.0001) and there were more female patients (50% vs 15%, p<0.00001) compared to group B. The prevalence of diabetes mellitus (58% vs 16%) and precordial ST segment depression on admission ECG (81% vs 50%) were significantly higher in group A compared to group B (p<0.00001 and p=0.002 consecutively). In group A there was a higher rate of righ ventricular (25% vs 23%), posterior (26% vs 24%) and posterolateral myocardial infarction (19% vs 14%), but the differences were not statistically different. In group A patients had significantly higher rate of second- or third-degree AV block (46% vs 8%, p<0.00001), cardiogenic shock (35% vs 1%, p<0.00001) and mortality (46% vs 3%, p<0.00001) compared to group B. In a multivariate regression analysis diabetes mellitus (p=0.0003) and precordial ST segment depression on admission ECG (p=0.002) were found as the independent predictors of in-hospital CHF in patients with acute inferior MI. CHF and ST segment depression on admission ECG were found as the independent predictors of in-hospital mortality (p<0.00001, p=0.04 consecutively). Patients with CHF complicating acute inferior MI have more unfavorable demographic and clinical characteristics on admission, higher rate of in-hospital complications and mortality. History of diabetes mellitus and precordial ST segment depression on admission ECG have an independent predictive value for CHF in this particular group of patients.     

急性心肌梗死合并心原性休克患者的血运重建治疗

心源性休克是急性心肌梗死患者最严重的并发症。虽然已经有了多种药物治疗、综合的监护管理以及先进的器械辅助,但急性心肌梗死合并心源性休克患者依旧保持着较高的死亡率。多项研究表明,尽早进行血运重建治疗是目前唯一可以明显改善急性心肌梗死合并心源性休克患者预后的治疗措施。因此尽早进行血运重建治疗是急性心肌梗死合并心源性休克患者治疗中最重要的一环。该文综述了其研究进展。     

Primary angioplasty for cardiogenic shock complicating acute myocardial infarction.

To evaluate the role of primary percutaneous transluminal coronary angioplasty in cardiogenic shock, 53 patients admitted with the diagnosis of acute myocardial infarction and cardiogenic shock were studied. Thirty-five (66.0%) patients received intravenous thrombolytic therapy (streptokinase 15 lac units) and 18 (34.0%) underwent primary percutaneous transluminal coronary angioplasty. There was no significant difference in the mean age, risk factor profile, presence of prior myocardial infarction, site of myocardial infarction and cardiac enzyme levels at presentation between the two groups. More male patients were present in the group undergoing primary percutaneous transluminal coronary angioplasty (94.44% vs 68.57%; p = 0.04). The time delay between the onset of symptoms and presentation to the hospital did not differ significantly between the two groups (318.9 vs 320.0 minutes; p = NS). In the primary percutaneous transluminal coronary angioplasty group, 17 patients had a single infarct-related artery and one had both left anterior descending and right coronary artery occlusion. Thus in 18 patients, 19 vessels were attempted. Angiographic success (< 50% residual stenosis) was achieved in 15 (78.94%) vessels of which TIMI III flow was achieved in 10 (52.63%) vessels and TIMI II flow in five (26.31%). Intra-aortic balloon pump was needed in five (27.77%) patients undergoing coronary angioplasty. In-hospital mortality was 27.77 percent in patients undergoing primary percutaneous transluminal coronary angioplasty and 57.14 percent in patients receiving intravenous thrombolytic therapy (p = 0.04). In the thrombolytic therapy group, mortality was higher (85.91%) in patients presenting six hours or later after the onset of symptoms as compared to those presenting in less than six hours of the onset of symptoms (50%). In primary percutaneous transluminal coronary angioplasty group, mortality was 21.42 percent in patients with successful and 50 percent in patients with failed angioplasty. Thus, in patients with acute myocardial infarction and cardiogenic shock, an aggressive invasive strategy with primary percutaneous transluminal coronary angioplasty, as compared to intravenous thrombolytic therapy, is helpful in reducing in-hospital mortality.