Early revascularization improves survival in cardiogenic shock complicating acute myocardial infarction

Cardiogenic shock complicating acute myocardial infarction in elderly patients: does admission to a tertiary center improve survival?

BACKGROUND

The role of early revascularization among patients with acute myocardial infarction complicated by cardiogenic shock remains controversial. Angioplasty registries, while suggesting a benefit, are subject to selection bias, and clinical trials have been underpowered to detect early benefits. If an invasive strategy is beneficial in this population, patients admitted to hospitals with onsite coronary revascularization might be expected to have a better prognosis. We sought to determine whether access to cardiovascular resources at the admitting hospital influenced the prognosis of patients with acute myocardial infarction complicated by cardiogenic shock.

METHODS

By use of the Cooperative Cardiovascular Project database (a retrospective medical record review of Medicare patients discharged with acute myocardial infarction), we identified patients aged > or =65 years whose myocardial infarction was complicated by cardiogenic shock.

RESULTS

Of the 601 patients with cardiogenic shock, 287 (47.8%) were admitted to hospitals without revascularization services and 314 (52.2%) were admitted to hospitals with coronary angioplasty and coronary artery bypass surgery facilities. Clinical characteristics were similar across the subgroups. Patients admitted to hospitals with revascularization services were more likely to undergo coronary revascularization during the index hospitalization and during the first month after acute myocardial infarction. After adjustment for demographic, clinical, hospital, and treatment strategies, the presence of onsite revascularization services was not associated with a significantly lower 30-day (odds ratio 0.83, 95% CI 0.47, 1.45) or 1-year mortality (odds ratio 0.91, 95% CI 0.49, 1.72).

CONCLUSIONS

In a community-based cohort, patients with acute myocardial infarction complicated by cardiogenic shock did not have significantly different adjusted 30-day and 1-year mortality, irrespective of the revascularization capabilities of the admitting hospital.

Acute myocardial infarction due to left main coronary artery occlusion. Therapeutic strategy

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.

Long-term results after acute percutaneous transluminal coronary angioplasty in acute myocardial infarction and cardiogenic shock

The aim of this study was to determine the long-term outcome in unselected, consecutive patients after acute percutaneous transluminal angioplasty (PTCA) for acute myocardial infarction (AMI) complicated by cardiogenic shock. This involved a follow-up study from a prospectively conducted patient registry in a tertiary referral center. A total of 59 patients (10 female/49 male; median age 62 years (32-91)) with percutaneous transluminal cardiac interventions in primary cardiogenic shock were identified between January 1995 and January 2000. Twenty-two patients (37%) had been resuscitated successfully before intervention. The in-hospital mortality of shock patients was 36% (n=21, median age 68 (47-84)). The median follow-up of survivors was 18.1 (7-57.3) months, during which three further patients died (8%; two because of sudden cardiac deaths, one because of acute reinfarction). Achievement of thrombolysis in myocardial infarction (TIMI) flow III after acute PTCA (84% in survivors vs. 38% in non-survivors; P<0.001) and the absence of the left main coronary artery (3% survivors vs. 29% non-survivors; P=0.003) as culprit lesion in patients with cardiogenic shock was strongly associated with an improved survival rate. A second cardiac intervention was performed in seven patients (18%). Overall functional capacity of shock survivors was good. At final follow-up, 80% of the survivors were completely asymptomatic. One patient had angina pectoris NYHA II, five patients dyspnoea NYHA class II. Exercise stress-test was performed in 24 of the 38 surviving patients, median exercise capacity was 100% (range 55-113%) of the age adjusted predicted value. In unselected patients with cardiogenic shock due to AMI, treatment with acute PTCA resulted in an in-hospital mortality of 36%, low late mortality and good functional capacity in long-term survivors. TIMI flow grade III after acute PTCA in patients with acute myocardial infarction complicated by cardiogenic shock was strongly associated with an improved survival rate whereas the left main coronary artery as culprit lesion was associated with worse outcome.

Prognosis of patients who develop acute renal failure during the first 24 hours of cardiogenic shock after myocardial infarction

PURPOSE

Acute renal failure has important prognostic implications in critically ill patients, but the effects of acute renal failure on in-hospital mortality in the subset of patients with cardiogenic shock are not known.

SUBJECTS AND METHODS

All consecutive patients who presented with acute coronary syndrome at our cardiovascular intensive care unit from 1993 to 2000 and who were in cardiogenic shock were enrolled. Acute renal failure was defined as a urine volume < 20 mL/h associated with an increase in serum creatinine level > or = 0.5 mg/dL or > 50% above the baseline value.

RESULTS

There were 118 patients (83 men [70%]; mean [+/- SD] age, 66 +/- 10 years), 39 (33%) of whom developed acute renal failure within 24 hours after the onset of shock. In-hospital mortality was 87% (34/39) in patients with acute renal failure and 53% (42/79) in patients without acute renal failure (odds ratio [OR] = 6.0; 95% confidence interval [CI]: 2.1 to 17; P < 0.001). Other significant univariate predictors of mortality included the peak serum lactate level, epinephrine dose, and the maximum serum creatinine level. Multivariate logistic regression analysis identified acute renal failure as the only independent predictor of mortality.

CONCLUSION

Acute renal failure was common in patients with cardiogenic shock and strongly associated with in-hospital mortality.

Results of primary percutaneous transluminal coronary angioplasty plus abciximab with or without stenting for acute myocardial infarction complicated by cardiogenic shock

This study examines the effects of abciximab as adjunctive therapy in primary percutaneous transluminal coronary angioplasty (PTCA) for acute myocardial infarction (AMI) complicated by cardiogenic shock. Abciximab improves the outcome of primary PTCA for AMI, but its efficacy in cardiogenic shock remains unknown. Case report forms were completed in-hospital and follow-up was obtained by telephone, outpatient visit, and review of hospital readmission records. A total of 113 patients with cardiogenic shock from AMI were included. All underwent emergency PTCA during which abciximab was administered to 54 patients (48%). The 2 groups of patients who received and did not receive abciximab were similar at baseline. Coronary stents were implanted slightly more often in the abciximab group (59% vs 42%; p = 0.1). A significantly improved final TIMI flow, less no-reflow, and a decrease in vessel residual diameter stenosis occurred in the abciximab group. At 30-day follow-up, the composite event rate of death, myocardial reinfarction, and target vessel revascularization was better in the abciximab group (31% vs 63%; p = 0.002). The combination of abciximab and stents was synergistic and resulted in improvement of all components of the composite end point beyond that seen with each therapy alone. Thus, abciximab therapy improves the 30-day outcome of primary PTCA in cardiogenic shock, especially when combined with coronary stenting.

Emergency coronary stenting for complete thrombotic occlusion of an unprotected left main coronary artery in acute myocardial infarction complicated by cardiogenic shock in an octogenarian patient--a case report

This report concerns an 82-year-old white man, who was admitted with cardiogenic shock secondary to an acute anterior myocardial infarction with right bundle branch block requiring an intra-aortic balloon pump for hemodynamic support and mechanical ventilatory support for respiratory distress. An immediate cardiac catheterization with coronary angiography revealed a complete thrombotic occlusion of the left main coronary artery. Prompt stent-supported percutaneous transluminal coronary angioplasty to the occluded left main coronary artery, a critical stenosis of the ostial left anterior descending artery, and the left circumflex coronary artery, allowed for recovery from this life-threatening condition and subsequent discharge from the hospital of this octogenarian patient. It is suggested that in a critical clinical condition with particularly challenging coronary anatomical findings, stent-supported coronary angioplasty can be lifesaving treatment in selected patients with octogenarian status with acute myocardial infarction.

[Elective primary angioplasty in cardiogenic shock: results from a single center]

INTRODUCTION

Cardiogenic shock is the leading cause of death among patients hospitalized for acute myocardial infarction. Conventional treatment for acute myocardial infarction does not achieve a better outcome in these patients, but prior studies with emergency revascularization by coronary angioplasty seem to provide encouraging results.

PATIENTS AND METHOD

A retrospective study of the clinical and angiographic results of elective primary angioplasty in 48 patients with cardiogenic shock complicating acute myocardial infarction of less than 12 hours is described. Intraaortic balloon counterpulsation was used in 79% of the patients. Patients with cardiogenic shock secondary to mechanical complications were excluded.

RESULTS

Angiographic success, defined as a residual stenosis < 50% and final TIMI flow >/= 2, was achieved in 85% of the culprit lesions, and stents were implanted in 76%. Multivessel angioplasty was performed in 25% of the patients, and abciximab was used in 35% of the cases. Mean time from the onset of symptoms to angioplasty was 7.4 +/- 3.1 hours. In-hospital survival was 58%, and was 54% at six months follow-up.

CONCLUSIONS

Emergency coronary revascularization with primary angioplasty and intracoronary stenting is effective in patients with acute myocardial infarction and cardiogenic shock. TIMI flow >/= 2 is achieved in most patients, and mortality is reduced when compared with conservative treatment in historical series.

Primary angioplasty versus intravenous thrombolysis in acute myocardial infarction: can we define subgroups of patients benefiting most from primary angioplasty? Results from the pooled data of the Maximal Individual Therapy in Acute Myocardial Infarction Registry and the Myocardial Infarction Registry

OBJECTIVES

We sought to determine the effectiveness of primary angioplasty compared with thrombolysis in clinical practice.

BACKGROUND

In clinical practice, primary angioplasty for the treatment of acute myocardial infarction (AMI) has not yet been proven more effective than intravenous thrombolysis, nor have subgroups of patients been identified who would perhaps benefit from primary angioplasty.

METHODS

The pooled data of two AMI registries--the Maximal Individual TheRapy in Acute myocardial infarction (MITRA) study and the Myocardial Infarction Registry (MIR)--were analyzed. A total of 9,906 lytic-eligible patients with AMI, with a pre-hospital delay of < or =12 h, were treated with either primary angioplasty (n = 1,327) or thrombolysis (n = 8,579).

RESULTS

Despite differences in the patients' characteristics and concomitant diseases between the two groups, the prevalence of adverse risk factors was balanced. Univariate analysis of hospital mortality showed a more favorable course for patients treated with primary angioplasty: 6.4% versus 11.3% (odds ratio [OR] 0.54, 95% confidence interval [CI] 0.43 to 0.67). This was confirmed by logistic regression analysis (multivariate OR 0.58, 95% CI 0.44 to 0.77). Primary angioplasty was associated with a lower mortality in all subgroups analyzed. We observed a significant correlation between mortality and absolute risk reduction (r = 0.82, p < 0.0001) in the different subgroups: as mortality increased, there was an increase in absolute benefit of primary angioplasty compared with thrombolysis.

CONCLUSIONS

These large registry data showed the effect of primary angioplasty to be more favorable than thrombolysis for the treatment of patients with AMI in clinical practice. This effect was not restricted to special subgroups of patients. As mortality increased, the absolute benefit of primary angioplasty also increased.

Appropriate indications for the use of a percutaneous cardiopulmonary support system in cases with cardiogenic shock complicating acute myocardial infarction

Percutaneous cardiopulmonary support (PCPS) is now available for hemodynamic support in patients with cardiogenic shock, but there are no guidelines for its use. The present study determined the appropriate indications for the use of the PCPS in patients with cardiogenic shock complicating acute myocardial infarction (AMI). Sixty-four consecutive patients with cardiogenic shock complicating AMI had hemodynamic support with an intraaortic balloon pump (IABP; n=38) and/or PCPS (n=26). The shock score (0-15) was calculated immediately before starting these support systems to quantify the severity of shock. Multivariate logistic regression analysis determined the clinical factors affecting in-hospital mortality. The relationship between in-hospital prognosis and the shock score was also examined in the 2 groups. The most significant factor related to the in-hospital prognosis was the shock score (p=0.0007; OR 2.16, 95% CI: 1.37-3.39). Another related factor was revascularization; however, this relationship did not reach statistical significance (p=0.069; OR 0.06). Among the 13 cases whose shock score was 4-8 (moderate shock), 5 survived in the PCPS group, but only 1 of 19 patients survived in the IABP group (p<0.05). None of the patients in either group whose shock score was more than 9 survived. The severity of shock is the most reliable independent predictor of in-hospital mortality in patients with cardiogenic shock complicating AMI. Using PCPS in patients with moderate cardiogenic shock may improve their in-hospital survival, but it must be used before the shock becomes severe.

Factors predicting mortality in patients after myocardial infarction caused by left main coronary artery occlusion: significance of ST segment elevation in both aVR and aVL leads

Acute left main coronary artery obstruction is rare and most patients in this clinical setting die of sudden death or cardiogenic shock. During the past 8 years, we encountered 13 patients with acute myocardial infarction caused by total occlusion of the left main coronary artery (LMCA-AMI). Thus, we surveyed these patients, and attempted to elucidate helpful predictors related to the prognosis. Six of 13 patients with LMCA-AMI survived. Successful left coronary artery dilatation was achieved in all survivors (group S), and in 5 (71%) non-survivors (group non-S). The age was not different between the two groups. A past history of angina was confirmed in 83% of group S. while only in 29% of group non-S. Clinical findings such as time of onset of AMI, interval from the AMI onset to admission, elapsed period from the AMI onset to recanalization of LMCA and the value of CK on admission were not different between the two groups. However, cardiogenic shock occurred in only 1 patient (17%) in group S compared with 5 patients (71%) in group non-S. As emphasized in the literature, good collateral circulation to the left anterior descending artery was observed in 5 patients (83%) in group S, while not observed in group non-S. Electro cardiographically, ST elevation in the aVR lead was very characteristic. This finding was confirmed in 69% of the total patients. Noticeably, 5 out of 6 non-survivors (83%) showed ST elevation not only in leads aVR but also in the aVL lead. In addition to the absence of collateral circulation, this electrocardiographic finding, which obviously indicates the presence of extensive myocardial ischemia in the diseased heart, is a simple and important predictor suggesting a poor prognosis in LMCA-AMI patients.

Angiographic findings and clinical correlates in patients with cardiogenic shock complicating acute myocardial infarction: a report from the SHOCK Trial Registry. SHould we emergently revascularize Occluded Coronaries for cardiogenic shocK?

OBJECTIVES

We sought to delineate the angiographic findings, clinical correlates and in-hospital outcomes in patients with cardiogenic shock (CS) complicating acute myocardial infarction.

BACKGROUND

Patients with CS complicating acute myocardial infarction carry a grave prognosis. Detailed angiographic findings in a large, prospectively identified cohort of patients with CS are currently lacking.

METHODS

We compared the clinical characteristics, angiographic findings, and in-hospital outcomes of 717 patients selected to undergo angiography and 442 not selected, overall and by shock etiology: left or right ventricular failure versus mechanical complications.

RESULTS

Patients who underwent angiography had lower baseline risk and a better hemodynamic profile than those who did not. Overall, 15.5% of the patients had significant left main lesions on angiography, and 53.4% had three-vessel disease, with higher rates of both for those with ventricular failure, compared with patients who had mechanical complications. Among patients who underwent angiography, those with ventricular failure had significantly lower in-hospital mortality than patients with mechanical complications (45.2% vs. 57.0%; p = 0.021). Importantly, for patients with ventricular failure, in-hospital mortality also correlated with disease severity: 35.0% for no or single-vessel disease versus 50.8% for three-vessel disease. Furthermore, mortality was associated with the culprit lesion location (78.6% in left main lesion, 69.7% in saphenous vein graft lesions, 42.4% in circumflex lesions, 42.3% in left anterior descending lesions, and 37.4% in right coronary artery lesions), and Thrombolysis In Myocardial Infarction (TIMI) flow grade (46.5% in TIMI 0/1, 49.4% in TIMI 2 and 26% in TIMI 3).

CONCLUSIONS

Patients who underwent angiographic study in the SHOCK Trial Registry had a more benign cardiac risk profile, more favorable hemodynamic findings and lower in-hospital mortality than those for whom angiograms were not obtained. Patients with CS caused by ventricular failure had more severe atherosclerosis, and a different distribution of culprit vessel involvement but lower in-hospital mortality, than those with mechanical complications. Overall in-hospital survival correlates with the extent of coronary artery obstructions, location of culprit lesion and baseline coronary TIMI flow grade.

Impact of thrombolysis, intra-aortic balloon pump counterpulsation, and their combination in cardiogenic shock complicating acute myocardial infarction: a report from the SHOCK Trial Registry. SHould we emergently revascularize Occluded Coronaries for cardiogenic shocK?

OBJECTIVES

We sought to investigate the potential benefit of thrombolytic therapy (TT) and intra-aortic balloon pump counterpulsation (IABP) on in-hospital mortality rates of patients enrolled in a prospective, multi-center Registry of acute myocardial infarction (MI) complicated by cardiogenic shock (CS).

BACKGROUND

Retrospective studies suggest that patients suffering from CS due to MI have lower in-hospital mortality rates when IABP support is added to TT. This hypothesis has not heretofore been examined prospectively in a study devoted to CS.

METHODS

Of 1,190 patients enrolled at 36 participating centers, 884 patients had CS due to predominant left ventricular (LV) failure. Excluding 26 patients with IABP placed prior to shock onset and 2 patients with incomplete data, 856 patients were evaluated regarding TT and IABP utilization. Treatments, selected by local physicians, fell into four categories: no TT, no IABP (33%; n = 285); IABP only (33%; n = 279); TT only (15%; n = 132); and TT and IABP (19%; n = 160).

RESULTS

Patients in CS treated with TT had a lower in-hospital mortality than those who did not receive TT (54% vs. 64%, p = 0.005), and those selected for IABP had a lower in-hospital mortality than those who did not receive IABP (50% vs. 72%, p < 0.0001). Furthermore, there was a significant difference in in-hospital mortality among the four treatment groups: TT + IABP (47%), IABP only (52%), TT only (63%), no TT, no IABP (77%) (p < 0.0001). Patients receiving early IABP (< or = 6 h after thrombolytic therapy, n = 72) had in-hospital mortality similar to those with late IABP (53% vs. 41%, n = 64, respectively, p = 0.172). Revascularization rates differed among the four groups: no TT, no IABP (18%); IABP only (70%); TT only (20%); TT and IABP (68%, p < 0.0001); this influenced in-hospital mortality significantly (39% with revascularization vs. 78% without revascularization, p < 0.0001).

CONCLUSIONS

Treatment of patients in cardiogenic shock due to predominant LV failure with TT, IABP and revascularization by PTCA/CABG was associated with lower in-hospital mortality rates than standard medical therapy in this Registry. For hospitals without revascularization capability, a strategy of early TT and IABP followed by immediate transfer for PTCA or CABG may be appropriate. However, selection bias is evident and further investigation is required.

Cardiogenic shock with non-ST-segment elevation myocardial infarction: a report from the SHOCK Trial Registry. SHould we emergently revascularize Occluded coronaries for Cardiogenic shocK?

OBJECTIVES

We sought to determine the outcomes of patients with cardiogenic shock (CS) complicating non-ST-segment elevation acute myocardial infarction (MI).

BACKGROUND

Such patients represent a high-risk (ST-segment depression) or low-risk (normal or nonspecific electrocardiographic findings) group for whom optimal therapy, particularly in the setting of shock, is unknown.

METHODS

We assessed characteristics and outcomes of 881 patients with CS due to predominant left ventricular (LV) dysfunction in the SHOCK Trial Registry.

RESULTS

Patients with non-ST-segment elevation MI (n = 152) were significantly older and had significantly more prior MI, heart failure, azotemia, bypass surgery, and peripheral vascular disease than patients with ST-elevation MI (n = 729). On average, the groups had similar in-hospital LV ejection fractions (approximately 30%), but patients with non-ST-elevation MI had a lower highest creatine kinase and were more likely to have triple-vessel disease. Among patients selected for coronary angiography, the left circumflex artery was the culprit vessel in 34.6% of non-ST-elevation versus 13.4% of ST-elevation MI patients (p = 0.001). Despite having more recurrent ischemia (25.7% vs. 17.4%, p = 0.058), non-ST-elevation patients underwent angiography less often (52.6% vs. 64.1%, p = 0.010). The proportion undergoing revascularization was similar (36.8% for non-ST-elevation vs. 41.9% ST-elevation MI, p = 0.277). In-hospital mortality also was similar in the two groups (62.5% for non-ST-elevation vs. 60.4% ST-elevation MI). After adjustment, ST-segment elevation MI did not independently predict in-hospital mortality (odds ratio, 1.30; 95% confidence interval, 0.83 to 2.02; p = 0.252).

CONCLUSIONS

Patients with CS and non-ST-segment elevation MI have a higher-risk profile than shock patients with ST-segment elevation, but similar in-hospital mortality. More recurrent ischemia and less angiography represent opportunities for earlier intervention, and early reperfusion therapy for circumflex artery occlusion should be considered when non-ST-elevation MI causes CS.

Diabetes mellitus in cardiogenic shock complicating acute myocardial infarction: a report from the SHOCK Trial Registry. SHould we emergently revascularize Occluded Coronaries for cardiogenic shocK?

OBJECTIVES

We sought to examine the role of diabetes mellitus in cardiogenic shock (CS) complicating acute myocardial infarction (AMI) in the SHOCK Trial Registry.

BACKGROUND

The characteristics, outcomes and optimal treatment of diabetic patients with CS complicating AMI have not been well described.

METHODS

Baseline characteristics, clinical and hemodynamic measures, treatment variables, shock etiologies and comorbid conditions were compared for 379 diabetic and 784 nondiabetic patients. Logistic regression was used to examine the association between diabetes and in-hospital mortality, after adjustment for baseline differences.

RESULTS

Diabetics were less likely than nondiabetics to undergo thrombolysis (28% vs. 37%; p = 0.002) or attempted revascularization (40% vs. 49%; p = 0.008). The survival benefit for diabetics selected for percutaneous or surgical revascularization (55% vs. 19% without revascularization) was similar to that for nondiabetics (59% vs. 25%). Overall unadjusted in-hospital mortality was significantly higher for diabetics (67% vs. 58%; p = 0.007), but diabetes was only a borderline predictor of mortality after adjustment for baseline and treatment differences (odds ratio for death, 1.36; 95% confidence interval, 1.00 to 1.84; p = 0.051).

CONCLUSIONS

Diabetics with CS complicating AMI have a higher-risk profile at baseline, but after adjustment, diabetics have an in-hospital survival rate that is only marginally lower than that of nondiabetics. Diabetics who undergo revascularization derive a survival benefit similar to that of nondiabetics.

Cardiogenic shock complicating acute myocardial infarction--etiologies, management and outcome: a report from the SHOCK Trial Registry. SHould we emergently revascularize Occluded Coronaries for cardiogenic shocK?

OBJECTIVES

This SHOCK Study report seeks to provide an overview of patients with cardiogenic shock (CS) complicating acute myocardial infarction (MI) and the outcome with various treatments. The outcome of patients undergoing revascularization in the SHOCK Trial Registry and SHOCK Trial are compared.

BACKGROUND

Cardiogenic shock is the leading cause of death in patients hospitalized for acute MI. The randomized SHOCK Trial reported improved six-month survival with early revascularization.

METHODS

Patients with CS complicating acute MI who were not enrolled in the concurrent randomized trial were registered. Patient characteristics were recorded as were procedures and vital status at hospital discharge.

RESULTS

Between April 1993 and August 1997, 1,190 patients with CS were registered and 232 were randomized in the SHOCK Trial. Predominant left ventricular failure (78.5%) was most common, with isolated right ventricular shock in 2.8%, severe mitral regurgitation in 6.9%, ventricular septal rupture in 3.9% and tamponade in 1.4%. In-hospital Registry mortality was 60%, with ventricular septal rupture associated with a significantly higher mortality (87.3%) than all other categories (p < 0.01). The risk profile and mortality were lower for Registry patients who were managed with thrombolytic therapy and/or intra-aortic balloon counter-pulsation, coronary angiography, angioplasty and/or coronary artery bypass surgery. After adjusting for these differences, the extent to which survival was improved with early revascularization was similar to that observed in the randomized SHOCK Trial.

CONCLUSIONS

In this prospective Registry the etiology of CS was a mechanical complication in 12%. The similarity of the beneficial treatment effect in patients undergoing early revascularization in the SHOCK Trial Registry and SHOCK Trial provides strong support for the generalizability of the SHOCK Trial results.

Elective coronary stent implantation in cardiogenic shock complicating acute myocardial infarction: in-hospital and six-month clinical and angiographic results

Effective treatment of patients with acute myocardial infarction and cardiogenic shock depends on restoring persistent patency of the infarct-related artery. Coronary stenting, reducing abrupt or delayed closure related to dissection and suboptimal result, may improve PTCA results in cardiogenic shock. Eighteen patients (14 males and 4 females, mean age 59 +/- 7 years), referred to catheterization laboratory for acute myocardial infarction and shock, had elective stent implantation during 14 primary and 4 rescue PTCA. Time delay between shock onset and PTCA was 4.1 +/- 3 hr (range, 30 min to 12 hr). The IRA was LAD in seven patients (38%), LCx in two (11%), and RCA in eight (45%). One patient (5.%) had distal LMCA occlusion. Stent deployment was successful in 100% of patients and resulted in TIMI 3 flow in 13 (72%) patients. In 13 (72%) cases, cardiogenic shock gradually resolved and the patients were discharged alive. Five patients (28%) died because of irreversible hemodynamic deterioration without evidence of reinfarction. At 6-month follow-up, all the discharged patients were alive and no patient had reinfarction or recurrent angina. Heart transplant was required in one patient 5 months after stenting because of refractory congestive heart failure. Angiography demonstrated patency of all the coronary arteries treated, with TIMI 3 flow in all patients. Stent restenosis rate was 30%, and target lesion revascularization with CABG or re-PTCA was not required in any case. LV function improved from 39% +/- 15% to 51% +/- 15% (P < 0.01). Elective coronary stenting is an effective treatment for acute myocardial infarction complicated by cardiogenic shock and may improve acute and long-term survival.

[Reperfusion therapy and mechanical circulatory support in patients in cardiogenic shock]

Cardiogenic shock is a state of inadequate tissue perfusion due to cardiac dysfunction, which is most commonly caused by acute myocardial infarction. The pathophysiology of cardiogenic shock is characterized by a downward spiral: ischemia causes myocardial dysfunction, which, in turn, augments the ischemic damage and the energetical imbalance. With conservative therapy, mortality rates for patients with cardiogenic shock are frustratingly high reaching more than 80%. Additional thrombolytic therapy has not been shown to significantly improve survival in such patients. Emergency cardiac catheterization and coronary angioplasty, however, seem to improve the outcome in shock-patients, which most probably is due to rapid and complete revascularization generally reached by angioplasty. In addition to interventional therapy with rapid coronary revascularization, the use of mechanical circulatory support may interrupt the vicious cycle in cardiogenic shock by stabilizing hemodynamics and the metabolic situation. Different cardiac assist devices are available for cardiologists and cardiac surgeons: 1. intraaortic balloon counterpulsation (IABP), 2. implantable turbine-pump (Hemopump), 3. percutaneous cardiopulmonary bypass support (CPS), 4. right heart, left heart, or biventricular assist devices placed by thoracotomy, and 5. intra- and extrathoracic total artificial hearts. Since percutaneous application is possible with IABP, Hemopump and CPS, these devices are currently used in interventional cardiology. The basic goals of the less invasive intraaortic balloon counterpulsation (IABP; Figure 1) are to stabilize circulatory collapse, to increase coronary perfusion and myocardial oxygen supply, and to decrease left ventricular workload and myocardial oxygen demand (Figure 2). Since the advent of percutaneous placement, IABP has been used by an increasing number of institutions (Figure 3). In addition to cardiogenic shock, the system may be of use in a variety of other indications in the catheterization laboratory and intensive care unit, including weaning from percutaneous cardiopulmonary bypass, in ischaemic left ventricular failure, in unstable angina, in high risk PTCA, and in prophylactic support in patients with myocardial infarction and successful revascularization. Animal experimental data showed that IABP may improve success of thrombolysis and recent clinical data suggest that survival is enhanced and transfer for revascularization is facilitated when patients with myocardial infarction and cardiogenic shock undergo thrombolysis and IABP rather than thrombolysis alone. A lot of studies had demonstrated before, that combined use of counterpulsation and revascularization therapy (i.e. coronary bypass surgery or angioplasty) may improve prognosis in patients with myocardial infarction complicated by cardiogenic shock (Table 1). In such patients, early treatment with IABP is most important: Multivariate analysis identified early IABP-support with a duration of shock to IABP-treatment of > or = 4 hours as an independent predictor of a positive short-term outcome. In shock-patients with postinfarction ventricular septal defect, IABP provides a marked hemodynamic improvement, and a significant decrease in shunt-flow (Figure 5). However, despite initial stabilization with IABP, such patients need immediate surgical repair of the septal defect to avoid hemodynamic deterioration. The rate of complications related to percutaneous IABP was significantly attenuated by employing catheters of reduced size. Using 9.5-F catheters, a long duration of counterpulsation emerged as the most significant factor associated with complications. In our hospital, those patients with 9.5-F catheters in whom counterpulsation did not exceed 48 hours had a low complication rate of 3.9%. The Hemopump is a catheter-mounted transvalvular left ventricular assist device intended for surgical placement via the femoral artery (Figures 6 and 7). (ABSTRACT TRUNCATED)

Spectrum of reperfusion strategies and factors influencing the use of primary angioplasty in patients with acute myocardial infarction admitted to hospitals with the facilities to perform primary angioplasty. Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) Study Group

OBJECTIVE

To determine the frequency of the use of primary angioplasty in patients with acute myocardial infarction and the factors influencing its indications in hospitals with the facilities to perform this treatment.

DESIGN

Data from the maximal individual therapy in acute myocardial infarction (MITRA) trial were analysed, concerning the effects of the decisions of individual hospitals, the time of admission of patients, and the effects of patient characteristics on the selection of reperfusion treatment.

PATIENTS

Between June 1994 and January 1997 eight hospitals treated 1532 patients with acute myocardial infarction. 418 (27.3%) were treated conservatively, 641 (41.8%) were treated using intravenous thrombolysis, 387 (25.3%) were treated using primary angioplasty, and 86 (5.6%) received a combination of thrombolysis and angioplasty.

RESULTS

The proportion of patients treated with primary angioplasty varied from 1.8% to 57.7% among the eight hospitals. The use of primary angioplasty during non-office hours also showed wide variation, ranging from 20% to 54% between centres. The use of thrombolysis was comparatively evenly distributed during the non-office hours, ranging from 50-69%. Four hospitals with a primary angioplasty use rate > 30% showed no difference in the proportion of patients with contraindications for thrombolysis, high risk patients, or a combination of both, when compared with four hospitals with a lower rate of primary angioplasty use (98/322 (30.4%) v 19/65 (29. 2%), respectively, p = 0.847).

CONCLUSIONS

In hospitals with the facilities for performing primary angioplasty the most important factors influencing its use were the discretion of the individual hospital and the time of patient admission. Characteristics of patients did not influence the choice of reperfusion treatment

Early revascularization in acute myocardial infarction complicated by cardiogenic shock. SHOCK Investigators. Should We Emergently Revascularize Occluded Coronaries for Cardiogenic Shock

BACKGROUND

The leading cause of death in patients hospitalized for acute myocardial infarction is cardiogenic shock. We conducted a randomized trial to evaluate early revascularization in patients with cardiogenic shock.

METHODS

Patients with shock due to left ventricular failure complicating myocardial infarction were randomly assigned to emergency revascularization (152 patients) or initial medical stabilization (150 patients). Revascularization was accomplished by either coronary-artery bypass grafting or angioplasty. Intraaortic balloon counterpulsation was performed in 86 percent of the patients in both groups. The primary end point was mortality from all causes at 30 days. Six-month survival was a secondary end point.

RESULTS

The mean age of the patients was 66+/-10 years, 32 percent were women and 55 percent were transferred from other hospitals. The median time to the onset of shock was 5.6 hours after infarction, and most infarcts were anterior in location. Ninety-seven percent of the patients assigned to revascularization underwent early coronary angiography, and 87 percent underwent revascularization; only 2.7 percent of the patients assigned to medical therapy crossed over to early revascularization without clinical indication. Overall mortality at 30 days did not differ significantly between the revascularization and medical-therapy groups (46.7 percent and 56.0 percent, respectively; difference, -9.3 percent; 95 percent confidence interval for the difference, -20.5 to 1.9 percent; P=0.11). Six-month mortality was lower in the revascularization group than in the medical-therapy group (50.3 percent vs. 63.1 percent, P=0.027).

CONCLUSIONS

In patients with cardiogenic shock, emergency revascularization did not significantly reduce overall mortality at 30 days. However, after six months there was a significant survival benefit. Early revascularization should be strongly considered for patients with acute myocardial infarction complicated by cardiogenic shock.

[Therapy of acute myocardial infarct--primary PTCA or thrombolysis?]

Since reperfusion of the infarct-related coronary artery has been established as a mainstay in the treatment of acute myocardial infarction (AMI) mechanical recanalization by direct angioplasty has been used as an alternative to the standard treatment with thrombolysis. Direct PTCA is more efficient than thrombolysis in terms of reperfusion rates, whereas thrombolysis is more readily available. Thrombolysis reduces mortality from AMI by approximately 25%. The clinical efficacy is strongly time-dependent, and treatment within the first hour of AMI improves survival by nearly 50% by preventing transmural infarction in a significant proportion of the patients. The disadvantage of thrombolysis is its limited efficacy in terms of rapid, complete and sustained patency of the infarct vessel yielding optimal results in only 50% of the patients. Direct PTCA is generally agreed to be more efficient to recanalize the infarct vessel, but its clinical advantage remains controversial. The first randomized studies of direct PTCA in AMI from highly specialized centers in selected patients reported success rates of coronary reperfusion up to 97% resulting in a trend to less death and reinfarction, but the differences were significant only in a metaanalysis of these small studies. The real world of direct PTCA has been depicted by a large registry in Germany of the Arbeitsgemeinschaft Leitender Kardiologischer Krankenhausärzte (ALKK) now including more than 4,000 direct PTCA-procedures since 1994. In this registry, the success rate of direct PTCA was 87% as defined by a final TIMI-grade 3 perfusion of the infarct vessel which is close to the data of the MITI-registry and the GUSTO IIb study. Failed PTCA was associated with an exceptionally high mortality rate of 36% confirming earlier observational reports. The non-randomized comparison of thrombolysis and direct PTCA in the MITI-registry showed no differene in survival or reinfarction rates, and the randomized GUSTO IIb substudy of direct PTCA versus front-loaded alteplase showed a small advantage in death and reinfarction rates at 30 days which dissipated over time leaving no significant clinical advantage of direct PTCA over thrombolysis at 6 months. Thus, in myocardial infarction in general the advantage of direct PTCA over thrombolysis is at best minimal. The reason is very probably the longer time lag until the procedure is started, the lower success rate as compared to the first reports of some specialized centers, and the clearly negative impact of failed PTCA on survival. Moreover, the immediate success of direct PTCA seems to be overestimated by the operator as demonstrated by comparison of central and local estimates of the TIMI flow rates in GUSTO IIb. Improvements of direct PTCA in AMI might be possible by coronary stenting which has markedly increased to more than 60% during the last year in the ALKK-registry. This was accompanied by a slight decrease in death and reinfarction rates. Further improvements can be expected from GP IIb/IIIa platelet antagonists which are under clinical investigation. It has been claimed, that in cardiogenic shock direct PTCA is more effective than thrombolysis. This hypothesis is based on comparison of failed versus successful PTCA-attempts, but this comparison is not valid since failed procedures clearly increase mortality. In the GUSTO-1 study patients with cardiogenic shock had lower mortality with than without an early coronary angiogram. This survival advantage, however, was independent of revascularization since only half of the patients with an early angiogram had PTCA. The same was observed in the International Shock Registry, reflecting significant selection bias in that patients in relatively better condition will be taken to the cathlab whereas apparently hopeless cases will not. In the ALKK-registry half of the patients in cardiogenic shock died after direct PTCA casting doubt on the presumed high clinical efficacy of this strategy. (ABST

Reperfusion therapy in cardiogenic shock complicating acute myocardial infarction

The most frequent cause of cardiogenic shock complicating acute myocardial infarction is extensive myocardial damage involving a relevant amount of myocardium. Treatment is aimed at support for the circulation with the use of drugs and mechanical devices and at restoration of perfusion to the ischemic myocardium as soon as possible. Therefore, emergency coronary angiography is indicated in all patients. Coronary angioplasty is the first option in patients with suitable anatomy because it is the fastest available technique able to recanalize the infarct-related vessel. Stenting of the infarct artery must be considered because stent implantation has been shown to improve results in comparison with the balloon alone. Complete revascularization is likely to offer a better outcome in patients with multivessel disease. Coronary surgery is indicated as first-line intervention in patients who have a coronary anatomy not suitable for angioplasty; it may also serve to complete revascularization in patients with multivessel disease initially treated with emergency coronary angioplasty. In a hospital without facilities for emergency coronary interventions, mechanical circulatory support with an intra-aortic balloon pump should be instituted and thrombolysis started; then patients should be transferred immediately to a tertiary center to undergo coronary angiography and revascularization procedures, if needed. In patients not benefiting from this aggressive revascularization strategy who develop irreversible extensive myocardial damage, heart transplantation must be considered.

Primary percutaneous transluminal coronary angioplasty for acute myocardial infarction in patients not included in randomized studies. Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) Study Group

Patients with acute myocardial infarction included in randomized trials comparing primary percutaneous transluminal coronary angioplasty (pPTCA) with thrombolysis represent a special subgroup of patients with a low event rate. Patients excluded from these trials represent a variety of different subgroups, with different patient characteristics and possibly different clinical event rates. Primary PTCA was performed in 491 consecutive patients with acute myocardial infarction in the prospective multicenter observational Maximal Individual Therapy in Acute Myocardial Infarction trial. They were divided into the following groups: group I, patients fulfilling the inclusion criteria of the randomized trials (284 of 491, 58%); group II, patients not included in these trials (207 of 491, 42%). Of group II the following subgroups were defined: group IIa, patients in cardiogenic shock (20 of 491, 4.1%); group IIb, patients with a left bundle branch block (12 of 491, 2,4%); group IIc, patients with contraindications for thrombolysis (42 of 491, 8.6%); group IId, patients with a nondiagnostic first electrocardiogram (95 of 491, 19.3%); group IIe, patients with a prehospital delay of > 12 hours (72 of 491, 14.7%); group IIf, patients with an unknown prehospital delay (30 of 491, 6.1%). A comparison of groups I and II showed similar baseline characteristics but a higher clinical event rate during hospitalization was seen in group II: combined end point of death, reinfarction, heart failure equal to or greater than NYHA class III, any stroke or postinfarction angina, 26.6% versus 18%; p = 0.022. Hospital deaths were nearly twice as high in these patients, without reaching statistical significance (10.6% vs 6%; p = 0.06). The subgroups of group II showed quite different rates of clinical events. In-hospital death rates were: IIa, 40% (8 of 20); IIb, 8% (1 of 12); IIc, 12% (5 of 42); IId, 5% (5 of 95); IIe, 6% (4 of 72); and IIf, 13% (4 of 30). The incidence of the combined end point was 60% (12 of 20) in IIa, 33% (4 of 12) in IIb, 29% (12 of 42) in IIc, 16% (15 of 95) in IId, 26% (19 of 72) in IIe, and 33% (10 of 30) in IIf. Thus, in clinical practice, about half of the patients treated with pPTCA would not have been included in randomized trials comparing pPTCA with thrombolysis. These patients represent a population at higher risk for in hospital clinical events. However, they do represent very different nonhomogenous subgroups with different clinical event rates.

Efficacy of invasive strategy for the management of acute myocardial infarction complicated by cardiogenic shock

This retrospective study evaluates the influence of an invasive strategy of urgent coronary revascularization on the in-hospital mortality of patients with acute myocardial infarction (AMI) complicated early by cardiogenic shock. Among 1,981 patients with AMI admitted to our institution from 1994 to 1997, 162 patients (8.2%) developed cardiogenic shock unrelated to mechanical complications. The strategy of management was considered invasive if an urgent coronary angiography was indicated within 24 hours of symptom onset. Every other strategy was considered conservative. Fifty-seven patients who developed the shock late or after a revascularization procedure, or who died on admission, were excluded. The strategy was invasive in 73 patients (70%). Five of them died before angiography could be performed and 65 underwent angioplasty (success rate 72%). By univariate analysis the invasive strategy was associated with a lower mortality than conservative strategy (71% vs 91%, p = 0.03), but this association disappeared after adjustment for baseline characteristics. Older age, nonsmoking, and previous ischemic heart disease were independent predictors of mortality. In conclusion, we have failed to demonstrate that a strategy of urgent coronary revascularization within 24 hours of symptom onset for patients with AMI complicated by cardiogenic shock is independently associated with a lower in-hospital mortality. This strategy was limited by the high mortality within 1 hour of admission in patients with cardiogenic shock, the modest success rate of angioplasty in this setting, and the powerful influence of some adverse baseline characteristics on prognosis.

Differences in patients with acute myocardial infarction treated with primary angioplasty or thrombolytic therapy. Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) Study Group

BACKGROUND

Little is known about the differences in patients with acute myocardial infarction (AMI) treated with primary angioplasty or intravenous thrombolysis in clinical practice.

METHODS

In all, 5,906 patients with AMI were registered by the Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) study. Of these, 491 (8.3%) patients were treated with primary angioplasty and 2,817 (47.7%) with intravenous thrombolysis.

RESULTS

There were only minor differences in baseline characteristics between the two groups. Prehospital delay time (median) was longer in the angioplasty group than in the thrombolysis group (161 vs. 120, p = 0.001), as was door-to-treatment time (88 vs. 30 min; p = 0.001). Patients treated with primary angioplasty more often had contraindications for thrombolytic therapy (12.9 vs. 6%, p = 0.001) and received beta blockers (65 vs. 58.1%, p = 0.004), heparin (98.2 vs. 91.6%, p = 0.001), angiotensin-converting enzyme (ACE) inhibitors (64.8 vs. 50%, p = 0.001) and "optimal" concomitant medication (56.4 vs. 42.9%, p = 0.001) more often. Univariate analysis showed a significant lower incidence of heart failure (5.3 vs. 16.5%, p = 0.001), postinfarct angina (7.3 vs. 16.4%, p = 0.001), in-hospital death (7.9 vs. 11.7%, p = 0.015) and the combined end point (21.6 vs. 40.3%, p = 0.001) in these patients. Stepwise logistic regression analysis revealed optimal concomitant medication [odds ratio (OR) = 0.94, 95% confidence interval (CI): 0.89-0.98) and the type of revascularization (OR = 0.65, 95% CI: 0.58-0.73) to be associated with a significant reduction in the incidence of the combined end point. Similar results were obtained in all predefined subgroups.

CONCLUSIONS

In clinical practice, patients treated with primary angioplasty are more often treated with beta blockers and ACE inhibitors than patients treated with intravenous thrombolysis. Thus, the selection of patients and the type of revascularization contributes to the reduction in mortality, overt heart failure, and postinfarct angina in these patients.

Comparison of primary angioplasty with conservative therapy in patients with acute myocardial infarction and contraindications for thrombolytic therapy. Maximal Individual Therapy in Acute Myocardial Infarction (MITRA) Study Group

The benefit of primary angioplasty in patients with acute myocardial infarction (AMI) and contraindications for thrombolysis compared to a conservative regimen is still unclear. Out of 5,869 patients with AMI registered by the MITRA trial, 337 (5.7%) patients had at least one strong contraindication for thrombolytic therapy. Out of these 337 patients 46 (13.6%) were treated with primary angioplasty and 276 (86.4%) were treated conservatively. Patients treated conservatively were older (70 years vs. 60 years; P=0.001), had a higher rate of a history with chronic heart failure (14.8% vs. 4.4%; P=0.053), a higher heart rate at admission (86 beats/min vs. 74 beats/min; P=0.001), and a higher prevalence of diabetes mellitus (27.1% vs. 12.8%; P=0.056). Patients treated with primary angioplasty received more often aspirin (91.3% vs. 74.6%; P=0.012), beta-blockers (60.9% vs. 46.1%; P = 0.062), angiotensin converting enzyme (ACE) inhibitors (71.7% vs. 44%; P=0.001), and the so-called optimal adjunctive medication (54.4% vs. 32.3%; P=0.004). Hospital mortality was significantly lower in patients who received primary angioplasty (univariate: 2.2% vs. 24.7%; P=0.001; multivariate: OR=0.46; P=0.0230). In patients with AMI and contraindications for thrombolytic therapy, primary angioplasty was associated with a significantly lower mortality compared to conservative treatment. Therefore, hospitals without the facilities to perform primary angioplasty should try to refer such patients to centers with the facilities for such a service, if this is possible in an acceptable time.

SHould we emergently revascularize Occluded Coronaries for cardiogenic shocK: an international randomized trial of emergency PTCA/CABG-trial design. The SHOCK Trial Study Group

BACKGROUND

Cardiogenic shock (CS) is the leading cause of death in patients hospitalized with acute myocardial infarction (MI). Nonrandomized studies suggest reduced mortality rate with revascularization.

TRIAL DESIGN

The SHOCK trial is a multicenter, randomized, and unblinded study with a Registry for trial-eligible and ineligible nonrandomized patients. The trial is testing the hypothesis that a direct invasive strategy of emergency revascularization for patients with cardiogenic shock complicating acute MI will reduce 30-day all-cause mortality rate by 20 absolute percentage points compared with initial medical stabilization. Eligibility criteria include development of CS within 36 hours of an acute transmural MI as evidenced by ST elevation or new left bundle branch block MI; clinical criteria for CS with hemodynamic confirmation; absence of a mechanical, iatrogenic, or other cause of shock; and enrollment within 12 hours of CS diagnosis. Patients randomly assigned to emergency revascularization immediately undergo coronary angiography, with percutaneous transluminal coronary angioplasty or coronary artery bypass grafting depending on the coronary anatomy. Patients assigned to initial medical stabilization may undergo revascularization >/=54 hours after randomization.

END POINTS

The primary end point is all-cause 30-day mortality after randomization. Secondary end points include death at trial termination, changes in left ventricular dimensions and function measured by echocardiography at randomization and 2 weeks later, and changes in quality of life and physical functioning from 2 weeks after discharge to 6 months after MI.

[Prognosis and management in patients with left main shock syndrome--emergency PTCA following CABG]

To clarify the optimal management and delineate the characteristics of patients with severe left main disease and cardiogenic shock as a result of an acute anterolateral myocardial infarction (left main shock syndrome), we analyzed the course of 13 such patients from September 1989 to June 1997. Of the 13 patients, 7 (53.8%) were managed with emergency coronary angioplasty (group A), 3 (23.1%) were treated with emergency coronary angioplsty following coronary bypass graft surgery (group B) and 3 (23.1%) underwent emergency coronary bypass graft surgery alone (group C). The interval from the beginning of myocardial ischemia to revascularization was 266 +/- 303 min. The degree of diameter stenosis found in the left main coronary artery was 98.1 +/- 1.8%. Overall in-hospital mortality for the 13 patient with left main shock syndrome was 76.9% (group A: 7/7; group B: 1/3; group C: 2/3, NS) and operative mortality was 61.5% (group A: 6/7; group B: 0/3; group C: 2/3, p = 0.03). When all 13 patients were examined together, the presence of ventricular tachycardia (VT) x ventricular fibrillation (Vf) was found to be the most powerful univariate predictor of operative death (p = 0.03). This is, 7 (87.5%) of the 8 patients with VT x Vf at presentation died within 30 postoperative days, and only 1 (20%) of the 5 patients without VT x Vf died (p = 0.03). Age, percent stenosis of the left main or right coronary arteries, the interval from the beginning of myocardial ischemia to revascularization, intubation, systolic pressure, fractional shortning, pulmonary artery pressure, pulmonary capillary wedge pressure, coronary risk factors, pulmonary edema, mitral regurgitation and percutaneous cardiopulmonary support failed to attain univariate significance at the P = .1 level. The postoperative peak CPK level was 15665 +/- 6710 IU/1 in operative death compared to 4733 +/- 2749 IU/1 in operative survival (p = 0.01). In conclusion, emergency coronary angioplasty following coronary bypass graft surgery for left main shock syndrome has been a very successful therapeutic option. Finally, for the entire group of 13 patients with left main shock syndrome, VT x Vf significantly decreased short-term survival.

Benefits, risks and alternatives of pulmonary artery catheterization

Twenty-five years after the introduction of the pulmonary artery catheter in clinical practice, its effectiveness in improving patient outcome is seriously questioned. Experts still recommend to use pulmonary artery catheters in selected critically ill patients, although evidence supporting these recommendations is lacking. The risks and the unclear benefits associated with this procedure should prompt the search for alternative, noninvasive monitoring techniques.

Systematic direct angioplasty and stent-supported direct angioplasty therapy for cardiogenic shock complicating acute myocardial infarction: in-hospital and long-term survival

OBJECTIVES

This prospective observational study was conducted to examine the apparent impact of a systematic direct percutaneous transluminal coronary angioplasty (PTCA) strategy on mortality in a series of 66 consecutive patients with acute myocardial infarction (AMI) complicated by cardiogenic shock, and to analyze the predictors of outcome after successful direct PTCA.

BACKGROUND

Previous studies have reported encouraging results with PTCA in patients with AMI complicated by cardiogenic shock, but a biased case selection for PTCA may have heavily influenced the observed outcomes.

METHODS

All patients admitted with AMI were considered eligible for direct PTCA, including those with the most profound shock, and no upper age limit was used. The treatment protocol also included stenting of the infarct-related artery for a poor or suboptimal angiographic result after conventional PTCA.

RESULTS

Between January 1995 and March 1997, 364 consecutive patients underwent direct PTCA, and in 66 patients AMI was complicated by cardiogenic shock. In patients with cardiogenic shock, direct PTCA had a success rate of 94%; an optimal angiographic result was achieved in 85%; primary stenting of the infarct-related artery was accomplished in 47%; and the in-hospital mortality rate was 26%. Univariate analysis showed that patient age, chronic coronary occlusion and completeness of revascularization were significantly related to in-hospital mortality. The mean follow-up period was 16 +/- 8 months. Survival rate at 6 months was 71%. Comparison of event-free survival in patients with a stented or nonstented infarct-related artery suggests an initial and long-term benefit of primary stenting.

CONCLUSIONS

Systematic direct PTCA, including stent-supported PTCA, can establish a Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow in the great majority of patients presenting with AMI and early cardiogenic shock. High performance criteria, including new devices such as coronary stents, should be considered in randomized trials where mechanical revascularization therapy is being tested.

Coronary revascularization surgery after myocardial infarction: impact of bypass surgery on survival after thrombolysis. GUSTO Investigators. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries

OBJECTIVES

This study sought to investigate the impact of surgical revascularization on outcome after myocardial infarction.

BACKGROUND

Small variations in rates of coronary artery bypass graft surgery (CABG) were noted among thrombolytic regimens in the Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries (GUSTO) trial, prompting the question of whether survival differences were partly related to differences in CABG rates.

METHODS

Patients in the GUSTO trial were randomized to one of four thrombolytic strategies. Of 40,861 patients with complete data, 3,526 underwent surgical revascularization during their initial hospital admission. Thirty-day and 1-year mortality rates were estimated using Kaplan-Meier techniques, and the impact of CABG as a time-dependent covariate on death was evaluated using a Cox survival model, adjusting for baseline prognostic factors.

RESULTS

The median time from study enrollment to CABG was 7 days across treatment groups. A 15% reduction in mortality for the tissue-type plasminogen activator (t-PA)-treated group was evident by the seventh day. Bypass surgery was a significant independent predictor of 30-day mortality (risk ratio 1.87) and a weaker predictor of 1-year mortality (risk ratio 1.21). Operative mortality was highest in patients with acute mitral regurgitation, ventricular septal defect or poor left ventricular function and in those undergoing CABG within the first 4 days of randomization.

CONCLUSIONS

The survival benefit of accelerated t-PA was not related to surgical revascularization. Bypass surgery was associated with excess mortality in the first year, but the added short-term mortality associated with CABG may be balanced by anticipated long-term benefit in specific groups of patients.

Primary angioplasty versus thrombolysis in the treatment of acute myocardial infarction. ALKK Study Group

This study investigates the hypothesis if primary angioplasty is superior to intravenous thrombolysis in the treatment of acute myocardial infarction (AMI). Small prospective randomized studies did not demonstrate a significant benefit regarding total mortality. A total of 14,980 patients with AMI were registered by "The 60-Minutes Myocardial Infarction Project," a prospective multicenter observational study: 210 of these patients were treated with primary angioplasty. A matched pair analysis comparing 1 primary angioplasty patient with 3 intravenous thrombolysis patients could be performed in 156 primary angioplasty patients. Criteria for matching were age, sex, location of AMI, systolic blood pressure, previous AMI, and prehospital delay. Patients with a bundle branch block or requiring resuscitation were excluded from analysis. Because of matching, both groups showed similar baseline characteristics. Patients with primary angioplasty had more relative contraindications for thrombolysis (ulcers: 10.3% vs 2.3%, recent intramuscular injections: 6.4% vs 1.6%, recent surgical interventions: 5.1% vs 1.1%, central punctures: 9% vs 3.9%). There was a tendency toward less combined adverse events in the primary angioplasty group (3.2% vs 5.7%, odds ratio [OR] = 0.55, 95% confidence interval [CI] = 0.21 to 1.44). In-hospital mortality rates in the primary angioplasty group and thrombolysis group were 4.3% and 10.3%, respectively (OR = 0.39, 95% CI = 0.17 to 0.92). The difference in mortality could already be demonstrated within the first 48 hours with 1.9% versus 5.3% deaths (OR = 0.35, 95% CI = 0.11 to 1.14). Thus this study indicates a superiority of primary angioplasty in comparison to intravenous thrombolysis in AMI even in a clinical routine setting, with a reduction of hospital mortality of about 60%.

Acute congestive heart failure. The need for aggressive therapy

Immediate management of congestive heart failure (CHF) is directed at reduction of preload and afterload and augmentation of forward blood flow and cardiac output. A variety of pharmacologic agents (e.g., diuretics, positive inotropic agents, vasodilators, vasopressors) are available for use in the intensive care unit. For patients in cardiogenic shock after acute myocardial infarction, pharmacologic measures coupled with direct reperfusion therapy using percutaneous revascularization can be lifesaving. Unfortunately, many survivors of acute CHF require longterm therapy. Current drug therapy cannot cure CHF, but a search for useful and safe oral positive inotropic agents continues, with the hope of improving both the quantity and quality of patients' lives. Heart transplantation is an alternative for some patients with severe ventricular dysfunction.

Decline in the rate of hospital mortality from acute myocardial infarction: impact of changing management strategies

This study examined the profile and management of acute myocardial infarction in patients hospitalized in the coronary care unit of Henry Ford Hospital to determine risk factors or treatments that best explained a decline in in-hospital mortality rates. During the 1980s and early 1990s, many therapeutic advances occurred in management of acute infarction. Overall and in-hospital mortality were observed also to decline, but little is known about the relation of newer treatments to clinical outcome. The study population consisted of 1798 patients with a confirmed diagnosis of myocardial infarction. Of these, 982 consecutive patients were hospitalized in the coronary care unit of Henry Ford Hospital from January 1981 through December 1984 and compared with the 816 consecutive patients hospitalized from January 1990 through October 1992. Data on baseline demographics, initial clinical features, in-hospital management, and in-hospital outcome were compared for the two groups. Logistic regression was used to define independent predictors of the improved outcome of the two groups. Demographic features of the earlier group were similar to those of the later cohort, with the exception of a greater incidence of diabetes and hypertension and a lesser incidence of angina and prior heart failure. The occurrence of non-Q wave infarction increased from 27% in the earlier to 39% in the later group, whereas the magnitude of peak creatine kinase elevation in serum was higher in the later group. Medical management differed significantly, with increased use of aspirin, thrombolytics, heparin, warfarin, nitrates, and beta-blockers and decreased use of antiarrhythmic agents, digoxin, and vasopressors in the later group. Coronary revascularization was performed during hospitalization in 6.4% of the earlier group of patients and 31.6% of the later group. In-hospital mortality was 14.7% in the earlier group and 7.4% in the later group. Multivariate logistic regression analysis showed that the difference in mortality between the two groups was best accounted for by increased use of beta-blockers, angioplasty, and thrombolytics, decreased incidence of cardiogenic shock and asystole, and decreased use of lidocaine. In conclusion, the presentation and in-hospital management of patients with acute myocardial infarction has changed from the early 1980s to the early 1990s. The improved hospital mortality rate may be associated with both the expanded use of effective therapies and a more favorable in-hospital course, although these are not mutually exclusive.

Cardiogenic shock: thrombolysis or angioplasty?

Cardiogenic shock (CGS) occurs in 3 to 20% of patients presenting with acute myocardial infarction (MI), and it generally involves dysfunction of at least 40% of the total myocardial mass. Prior to the advent of balloon angioplasty and thrombolysis, in-hospital mortality was greater than 75%. This mortality rate has been consistent in reported series despite the advent of cardiac intensive care units, vasopressor, inotropic, and vasodilator therapy. Intra-aortic balloon counterpulsation therapy provides hemodynamic improvement, and it may provide some mortality benefit when used in conjunction with appropriate revascularization. Survival studies have shown that patency of the infarct-related artery is a strong predictor of survival. No randomized trials have been completed to examine which reperfusion therapy best treats this emergent situation. Subgroup analysis of large scale, multicenter trials, although underpowered, has shown no improvement in mortality with use of thrombolytic agents, leading many to advise use of mechanical intervention. In patients who present with acute MI with contraindications to thrombolysis, primary angioplasty is the treatment of choice. At selected centers, primary angioplasty is comparable to or better than thrombolytic therapy for patients presenting with acute MI, with or without CGS. Studies examining angioplasty in patients with CGS have shown high procedural success rates (75%) and reduced in-hospital mortality (44%), particularly in those patients with successful revascularization. Emergency bypass surgery may improve survival, but it is costly, unavailable to many, and often leads to excessive delays in therapy. If available, we believe that primary angioplasty is the treatment of choice for patients with CGS.

Early and 1-year survival rates in acute myocardial infarction complicated by cardiogenic shock: a retrospective study comparing coronary angioplasty with medical treatment

Cardiogenic shock remains a frequently lethal complication of acute myocardial infarction. Early revascularization of the infarct-related artery by coronary angioplasty has been suggested to significantly improve patient survival. In-hospital and 1-year survival was assessed in 50 patients hospitalized for acute myocardial infarction complicated by cardiogenic shock. All patients received medical treatment and intraaortic balloon pump support. Thirty-three patients underwent coronary angioplasty (PTCA group), while 17 patients remained on conventional therapy (no PTCA group). The two groups were comparable for all baseline characteristics. Survival was significantly better in the PTCA group than in the no PTCA group: 64% versus 24% in-hospital survival (p = 0.007) and 52% versus 12% at 1 year (p = 0.006). When angioplasty was successful in achieving reperfusion, survival was further enhanced: in-hospital survival rate was 76% versus 25% in patients with unsuccessful angioplasty and 60% versus 25% at 1 year.

[Myocardial infarction and revascularization. Current indications]

The physiopathologic role of thrombosis in the genesis of myocardial infarction, began to be suspected early in the 20th century but its logical treatment, thrombolysis, was first used on a large scale only ten years ago. Today, it is well established that short, middle and long-term mortality is correlated to coronary permeability, the delay in the revascularization treatment start-up, its efficacy, its swiftness of action, and to the maintaining of permeability following reperfusion. The importance of time elapse before reperfusion is obtained was demonstrated as early as 1986 by the GISSI study. According to this study, the administration of streptokinase (compared to a conventional treatment) reduced mortality at 21 days respectively by 47%, 23%, and 17%, depending on whether patients were treated within one hour, three hours, or between 3 and 6 hours following the onset of the painful symptoms. One of the major teachings of the GUSTO study, reported at the end of 1993, was the confirmation of the so-called "open artery" theory: mortality at 30 days was of 4.5% among patients whose coronary circulation was restored at the 90th minute, whatever thrombolytic treatment was used, compared to 8.9% when the coronary artery remained occluded. The value of aspirin in preserving coronary permeability following thrombolysis was demonstrated by the ISIS-2 study: mortality at 5 weeks was reduced by 23% in the group of patients randomised to receive only aspirin, while it was reduced by 25% in the group of patients randomised to be treated with streptokinase, and by 42% in the group randomised to receive both aspirin and streptokinase, compared to the group who received neither aspirin nor streptokinase. However, mortality during the first days following randomisation was identical among the groups, with or without aspirin, which suggested its action was rather one of prevention against reocclusion than one of accelerating dissolution of the thrombus. However, in spite of improved therapeutical protocols, a normal flow, which is the major criteria for a reduced mortality, is only obtained at the 90th minute in 54% of the patients who were administered the up-to-date treatment ie aspirin-accelerated t-PA-heparin in combination.(ABSTRACT TRUNCATED AT 400 WORDS)

Contemporary reperfusion therapy for cardiogenic shock: the GUSTO-I trial experience. The GUSTO-I Investigators. Global Utilization of Streptokinase and Tissue Plasminogen Activator for Occluded Coronary Arteries

OBJECTIVES

This study sought to examine the incidence, temporal profile and clinical implications of shock in a large trial of thrombolytic therapy for acute myocardial infarction.

BACKGROUND

Despite advances in the treatment of acute ischemic syndromes, cardiogenic shock remains associated with significant morbidity and mortality.

METHODS

Patients who presented within 6 h of symptom onset were randomized to four treatment strategies: 1) streptokinase plus subcutaneous heparin; 2) streptokinase plus intravenous heparin; 3) accelerated recombinant tissue-type plasminogen activator (rt-PA) plus intravenous heparin; or 4) streptokinase and rt-PA plus intravenous heparin. The primary end point was 30-day all-cause mortality.

RESULTS

Shock occurred in 2,972 patients (7.2%): 315 (11%) had shock on arrival, and 2,657 (89%) developed shock after hospital admission. Reinfarction occurred in 11% of patients who developed shock compared with 3% of patients without shock. The mortality rate was significantly higher in patients who presented with (57%) or developed (55%) shock than in those without shock (3%) (p < 0.001). Shock developed significantly less frequently in patients receiving rt-PA. There were fewer deaths in patients who presented with shock and were treated with streptokinase plus intravenous heparin or who developed shock and were treated with streptokinase plus subcutaneous heparin. Patients who developed shock had a significantly lower 30-day mortality rate if angioplasty was performed.

CONCLUSIONS

Because cardiogenic shock occurred most often after admission and with recurrent ischemia and reinfarction, recognizing signs of incipient shock may improve outcome. Fewer patients treated with rt-PA developed shock, yet those developing shock had the same high mortality rate as those presenting with shock, regardless of treatment. Only angioplasty was associated with a significantly lower mortality rate.

Effectiveness of percutaneous transluminal coronary angioplasty for patients with medically refractory rest angina pectoris and high risk of adverse outcomes with coronary artery bypass grafting

This study was undertaken to test the hypothesis that percutaneous transluminal coronary angioplasty (PTCA) is a reasonable alternative to coronary artery bypass grafting (CABG) for some high-risk patients with medically refractory rest angina. Over a 5-year period, 1 operator at a tertiary Veterans Affairs Medical Center performed angioplasty on 624 patients, of whom 441 had unstable angina. Of these 441 patients, 288 had rest angina and 225 had medically refractory rest angina. Medically refractory unstable angina was defined as reversible myocardial ischemia occurring at rest in an intensive care unit setting with low flow oxygen despite the following medications: (1) oral aspirin, intravenous heparin, or both; (2) some combination of beta blocker, calcium blocker, and/or nitrate so that resting heart rate is < 70 beats/min or resting blood pressure < 140 mm Hg, or both. There were 207 patients with medically refractory rest angina who had > or = 1 of the following characteristics predictive of a more than twofold increased risk of operative death at CABG: age > 70 years, prior CABG, recent myocardial infarct, need for intravenous nitroglycerin, need for intraaortic balloon pump, and left ventricular ejection fraction < 0.35. Of these 207 patients, 11 died (5%) during index hospitalization, 196 (95%) were discharged, and 186 (90%) went home angina free. There were 2 emergency CABGs and 9 acute myocardial infarctions. At follow-up (3 to 60 months, average 24), there were 27 late deaths (for a total of 38 [18%]), 8 (4%) late CABGs, and 44 (21%) late PTCAs (with 17 [8%] late myocardial infarctions). The 2-year mortality of 18% for this cohort is comparable to a 21% 2-year mortality observed in a group of 1,073 "high-risk" patients who underwent CABG in the Veterans Affairs Medical Center from 1987 to 1988. These data support the hypothesis that PTCA provides an alternative to CABG in some high-risk patients with medically refractory rest angina.

Current spectrum of cardiogenic shock and effect of early revascularization on mortality. Results of an International Registry. SHOCK Registry Investigators

BACKGROUND

Cardiogenic shock remains the leading cause of death of patients hospitalized with acute myocardial infarction (MI). This study was conducted to examine (1) the current spectrum of cardiogenic shock, (2) the proportion of patients who are potential candidates for a trial of early revascularization, and (3) the apparent impact of early revascularization on mortality.

METHODS AND RESULTS

Nineteen participating centers in the United States and Belgium prospectively registered all patients diagnosed with cardiogenic shock. Two hundred fifty-one patients were registered. The mean age was 67.5 +/- 11.7 years, and 43% were women. Acute mitral regurgitation or ventricular septal rupture was the cause of shock in 8%. Concurrent conditions contributing to the development of shock were noted in 5%, and 2% had isolated right ventricular shock. Among the remaining 214 patients, nonspecific findings on the ECG associated with "nontransmural" MI were seen in 14%. The median time to shock diagnosis after MI was 8 hours. The overall in-hospital mortality was 66%. Patients clinically selected to undergo cardiac catheterization were significantly younger and had a lower mortality than those not selected (51% versus 85%, P < .0001) even if they were not revascularized (58%). Mortality for patients undergoing percutaneous transluminal coronary angioplasty (PTCA) was 60% (n = 55) and 19% (n = 16) for coronary artery bypass graft surgery (CABG). Sixty percent (n = 150) of registered patients were judged eligible for a trial of early revascularization. Trial-eligible patients were significantly younger (65.4 +/- 11.0 versus 70.6 +/- 11.9 years, P < .001), had an earlier median time to shock onset after MI (6.5 versus 17.5 hours, P = .003), and had lower mortality (62% versus 73%, P = .077) than ineligible patients.

CONCLUSIONS

Patients diagnosed with cardiogenic shock complicating acute MI are a heterogeneous group. Those eligible for a trial of early revascularization tended to have lower mortality. Patients selected to undergo cardiac catheterization had lower mortality whether or not they were revascularized. Emergent PTCA and CABG are promising treatment modalities for cardiogenic shock, but biased case selection for treatment may confound the data. Whether PTCA and CABG reduce mortality and which patient subgroups benefit most remain to be determined in a randomized clinical trial.