Successful coronary angioplasty in two patients with cardiogenic shock using the Nimbus Hemopump support device

Coronary and circulatory support strategies for percutaneous transluminal coronary angioplasty in high-risk patients

PTCA is now applied to patients with unstable acute ischemic syndromes, severe multivessel coronary artery disease, and impaired left ventricular function. To minimize the risk during angioplasty, several coronary and systemic circulation support approaches have been developed as adjuncts to high-risk angioplasty. Local coronary support techniques include the perfusion balloon catheter, the coronary stent, directional coronary atherectomy, laser balloon angioplasty, perfluorocarbon coronary perfusion, coronary sinus retroperfusion, and distal coronary hemoperfusion. Systemic circulatory support includes intraaortic balloon counterpulsation, cardiopulmonary support, the hemopump, and left heart partial bypass. These support devices, while associated with significant complications, may ultimately improve the safety of coronary angioplasty and allow its application to those who would otherwise not be candidates for revascularization.

Prediction of risk for hemodynamic compromise during percutaneous transluminal coronary angioplasty

The availability of circulatory support devices has increased the importance of accurately identifying patients at risk for hemodynamic compromise during percutaneous transluminal coronary angioplasty (PTCA). Accordingly, prospective evaluation of 3 criteria to predict hemodynamic compromise (defined as a decrease in systolic blood pressure > or = 20 to < 90 mm Hg during balloon inflation) in 157 patients (group A) undergoing PTCA was performed. Left ventricular ejection fraction < 35% had a sensitivity of 13% and a specificity of 95%. Greater than 50% of the myocardium at risk was associated with a sensitivity of 31% and a specificity of 85%. The angiographer's assessment of high risk for hemodynamic compromise had the highest sensitivity of 56% and a specificity of 86%. The clinical and angiographic characteristics of these patients were reviewed to identify risk factors retrospectively. Multivariate analysis of 28 variables identified multivessel disease, diffuse disease, myocardium at risk, and stenosis before PTCA as independent predictors of hemodynamic compromise. With use of this analysis, a 13-point weighted scoring system was created based on the regression of coefficients of the variables. Defining high risk for hemodynamic compromise as a risk score > or = 4, the sensitivity of this criterion in group A patients was 81% and the specificity was 74%. The scoring system was then prospectively applied to 61 consecutive patients (group B) undergoing PTCA. In using a risk score > or = 4 to define high risk, this scoring system had a sensitivity of 92% and a specificity of 92%.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiogenic shock complicating acute myocardial infarction: the use of coronary angioplasty and the integration of the new support devices into patient management

Conventional therapy for cardiogenic shock complicating acute myocardial infarction continues to be associated with a high in-hospital mortality rate. Hemodynamic support with new mechanical devices and emergency coronary revascularization may alter the long-term prognosis for patients with this complication. Between July 1985 and March 1990, 68 patients presented to the University of Michigan with acute myocardial infarction and cardiogenic shock. Interventions performed included thrombolytic therapy (46%), intraaortic balloon pump counterpulsation (70%), cardiac catheterization (86%), coronary angioplasty (73%), emergency coronary artery bypass grafting/ventricular septal defect repair (15%), Hemopump insertion (11%), percutaneous cardiopulmonary support (4%) and ventricular assist device (3%). The 30-day survival rate was significantly better in patients who had successful angioplasty of the infarct-related artery than in patients with failed angioplasty (61% vs. 7%, p = 0.002) or no attempt at angioplasty (61% vs. 14%, p = 0.003). This difference was maintained over the 1-year follow-up period. The only clinical variable that predicted survival was age less than 65 years. The early use of the new support devices in 10 patients was associated with death in 8 (80%), but this poor outcome may reflect a selection bias for an especially high risk population. Collectively, these recent data continue to suggest that emergency revascularization with angioplasty may reduce the mortality rate, but further study is required to define optimal utilization and integration of new support devices.

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.