Back to the Future in Cardiogenic Shock - Initial PCI of the Culprit Lesion Only

Clinical significance of residual ischaemia in acute myocardial infarction complicated by cardiogenic shock undergoing venoarterial-extracorporeal membrane oxygenation

AIMS

Although culprit-only revascularization during the index procedure has been recommended in patients with acute myocardial infarction (AMI) complicated by cardiogenic shock (CS), the reduction in residual ischaemia is also emphasized to improve clinical outcomes. However, few data are available about the significance of residual ischaemia in patients undergoing mechanical circulatory supports. This study aimed to evaluate the effects of residual ischaemia on clinical outcomes in patients with AMI undergoing venoarterial-extracorporeal membrane oxygenation (VA-ECMO).

METHODS AND RESULTS

Patients with AMI with multivessel disease who underwent VA-ECMO due to refractory CS were pooled from the RESCUE and SMC-ECMO registries. The included patients were classified into three groups according to residual ischaemia evaluated using the residual Synergy between percutaneous coronary intervention with Taxus and Cardiac Surgery (SYNTAX) score (rSS): rSS = 0, 0 < rSS ≤ 8, and rSS > 8. The primary outcome was 1-year all-cause death. A total of 408 patients were classified into the rSS = 0 (n = 100, 24.5%), 0 < rSS ≤ 8 (n = 136, 33.3%), and rSS > 8 (n = 172, 42.2%) groups. The cumulative incidence of the primary outcome differed significantly according to rSS (33.9 vs. 55.4 vs. 66.1% for rSS = 0, 0 < rSS ≤ 8, and rSS > 8, respectively, overall P < 0.001). In a multivariable model, rSS was independently associated with the risk of 1-year all-cause death (adjusted hazard ratio 1.03, 95% confidence interval 1.01-1.05, P = 0.003). Conversely, the baseline SYNTAX score was not associated with the risk of the primary outcome. Furthermore, when patients were stratified by rSS, the primary outcome did not differ significantly between the high and low delta SYNTAX score groups.

CONCLUSION

In patients with AMI with refractory CS who underwent VA-ECMO, residual ischaemia was associated with an increased risk of 1-year mortality. Future studies are needed to evaluate the efficacy and safety of revascularization strategies to minimize residual ischaemia in patients with CS supported with VA-ECMO.

CLINICAL TRIAL REGISTRATION

REtrospective and Prospective Observational Study to Investigate Clinical oUtcomes and Efficacy of Left Ventricular Assist Device for Korean Patients With Cardiogenic Shock (RESCUE), NCT02985008.

Acute kidney injury in cardiogenic shock: A comprehensive review

Acute kidney injury (AKI) is an ominous predictor of mortality in cardiogenic shock. The present review examines the pathophysiology of AKI in cardiogenic shock (CS), summarizes the pertinent literature including the diagnostic criteria/definitions for AKI and possible role of biomarkers, and identifies risk factors and possible therapeutic interventions for AKI in CS. Our review finds that AKI is common in patients with CS and is associated with increased morbidity and mortality. Urinary biomarkers of renal tubular injury appear more sensitive for detection of AKI but have yet to be incorporated into daily practice. Emerging data would suggest vasopressor choices, mechanical circulatory support, and renal replacement therapy may have important therapeutic roles in the management of CS.

Temporary circulatory support for cardiogenic shock

Cardiogenic shock can occur due to acute ischaemic or non-ischaemic cardiac events, or from progression of long-standing underlying heart disease. When addressing the cause of underlying disease, the management of cardiogenic shock consists of vasopressors and inotropes; however, these agents can increase myocardial oxygen consumption, impair tissue perfusion, and are frequently ineffective. An alternative approach is to temporarily augment cardiac output using mechanical devices. The use of these devices-known as temporary circulatory support systems-has increased substantially in recent years, despite being expensive, resource intensive, associated with major complications, and lacking high-quality evidence to support their use. This Review summarises the physiological basis underlying the use of temporary circulatory support for cardiogenic shock, reviews the evidence informing indications and contraindications, addresses ethical considerations, and highlights the need for further research.

Long-term outcomes following percutaneous coronary intervention to an unprotected left main coronary artery in cardiogenic shock

BACKGROUND

In cardiogenic shock with severe left main coronary artery stenosis (LM), limited information exists on short and longer-term outcomes. We sought to determine the outcomes of unprotected LM PCI in cardiogenic shock.

METHODS

Excluding patients with previous CABG, consecutive patients undergoing PCI in cardiogenic shock from the Melbourne Intervention Group registry between 2005 and 2013 were analysed. Those post LM PCI were compared to those post non-LM PCI. Patient and procedural data were collected with 30-day and 12-month follow-up. Australian National Death Index linkage was performed for long-term mortality analysis.

RESULTS

After excluding previous CABG, 18,069 procedures were performed during 1st January 2005 to 30th November 2013, 601 procedures in the setting of cardiogenic shock. Of these, 45 were performed to an isolated LM and 556 to a non-LM. Those with LM PCI were older and more likely to have a baseline left ventricular ejection fraction (LVEF) of <45%. The in-hospital, 30-day, 12-month and long-term mortality to 9 years in cardiogenic shock after LM PCI was 64.4%, 66.7%, 73.3% and 80.0% compared to 36.5%, 36.9%, 40.5% and 46.0%, after non-LM PCI (p < 0.001). On multivariate analysis, LM PCI was a significant independent predictor of long-term mortality (HR1.59, 95%CI 1.00-2.53, p = 0.048). Landmark analysis of survivors to discharge found the long-term mortality of LM PCI approaches 60% compared to 27% for those with non-LM PCI (p = 0.003).

CONCLUSION

Long-term outcomes after PCI to LM in cardiogenic shock are poor, with much of the excess in mortality occurring early. However, reasonable long-term survival was found beyond the initial high-risk period.

Culprit-Only or Complete Revascularization for ST-Elevation Myocardial Infarction in Patients with and Without Shock

ST-elevation myocardial infarction (STEMI) patients with multivessel disease and without shock are a common clinical entity, but the best approach to nonculprit vessel lesions remains controversial. In contrast, STEMI patients with shock do not appear to benefit from primary multivessel percutaneous coronary interventions (PCIs) during the index procedure. The optimal treatment strategy in a given STEMI patient involves an individualized approach, incorporating clinical, hemodynamic, and angiographic/imaging parameters. Patients with STEMI and cardiogenic shock may benefit from therapies other than PCI, such as mechanical cardiovascular support.

The expanding role of implantable devices to monitor heart failure and pulmonary hypertension

The epidemics of heart failure and, to a lesser extent, of pulmonary arterial hypertension continue unabated worldwide and are extremely costly in terms of loss of life and earnings, as well as the burden of health-care expenditure due to repeated hospitalization. The effectiveness of newly discovered therapies for the two conditions depends on their timely application. To date, symptoms have been used to guide the application and timing of therapy. Compelling evidence now exists that symptoms are preceded by several metabolic and haemodynamic changes, particularly a rise in intravascular pressures during exercise. These observations have stimulated the development of several implantable devices for the detection of impending unstable heart failure or pulmonary arterial hypertension, necessitating admission to hospital. In this Review, we summarize the rationale for monitoring patients with heart failure or pulmonary arterial hypertension, the transition from noninvasive to implantable devices and the current and anticipated clinical uses of these devices.

Mechanical circulatory devices in acute heart failure

PURPOSE OF REVIEW

Temporary circulatory support (TCS) with short-term mechanical circulatory support (MCS) devices is increasingly used as a salvage therapy for patients with refractory cardiogenic shock. This article provides an overview of current devices, their indications and management, and discusses results of recent case series and trials.

RECENT FINDINGS

Percutaneous active MCS devices (Impella, TandemHeart…) and venoarterial extracorporeal membrane oxygenation (VA-ECMO) are utilized as a bridge to 'decision' that includes weaning after cardiac function recovery, transplantation, long-term MCS and withdrawal in case of futility. VA-ECMO is considered the first-line TCS since it allows rapid improvement in oxygenation, is less expensive, and is also suitable for patients with biventricular failure. Combining Impella or intra-aortic balloon pump support with ECMO might decrease left ventricular pressure and improve outcomes. Sepsis-associated cardiomyopathy, massive pulmonary embolism, arrhythmic storm and Takotsubo-like cardiomyopathy are among emerging indications for TCS.

SUMMARY

TCS have become the cornerstone of the management of patients with cardiogenic shock, although the evidence supporting their efficacy is limited. VA-ECMO is considered the first-line option, with a growing number of accepted and emerging indications. Randomized clinical trials are now needed to determine the respective place of different MCS devices in cardiogenic shock treatment strategies.

Extracorporeal Life Support in Myocardial Infarction-Induced Cardiogenic Shock: Weaning Success

BACKGROUND

Outcome data of patients with acute myocardial infarction (AMI)-induced cardiogenic shock (CS) receiving extracorporeal life support (ECLS) are sparse.

METHODS

A consecutive series of 106 patients with AMI-induced CS receiving ECLS was evaluated regarding ECLS weaning success, hospital mortality, and long-term outcome. The Intraaortic Balloon Pump in Cardiogenic Shock II (IABP-SHOCK II) risk score was applied, and multivariable Cox regression analysis was performed.

RESULTS

Mean patient age was 58.2 ± 11.2 years, and 78.3% were men. In 34 patients (32.1%), ECLS was implemented during ongoing cardiopulmonary resuscitation. De novo AMI was present in 58 patients (54.7%), and percutaneous coronary intervention complications were causative among 48 patients (45.3%). Multivessel coronary artery disease was diagnosed among 73.6% with mean Synergy between PCI with Taxus and Cardiac Surgery (SYNTAX) scores of 30.8 ± 4.8. Actuarial survival was 54.4% at 30 days, 42.2% at 1 year, and 38.0% at 5 years and was significantly higher among patients with low and intermediate IABP-SHOCK II risk scores at ECLS onset (log-rank P = .017). ECLS weaning with curative intention after a mean perfusion time of 6.6 ± 5.1 days was feasible in 51 patients (48.1%) and more likely among patients with complete revascularization (P = .026). Multivariable Cox regression analysis identified complete revascularization (hazard ratio, 2.38; 95% confidence interval, 1.1 to 5.1; P = .028) and absence of relevant mitral regurgitation at ECLS discontinuation (hazard ratio, 2.71; 95% confidence interval, 1.2 to 6.0; P = .014) to be associated with beneficial long-term survival after ECLS discontinuation.

CONCLUSIONS

Emergency ECLS is a valuable option among patients with AMI-induced CS with low and intermediate IABP-SHOCK II risk scores. ECLS weaning is manageable, but additional revascularization of all nonculprit lesions is mandatory after ECLS implementation.

CULPRIT-SHOCK study

The treatment of patients with ST-segment elevation myocardial infarction concomitant with the presence of multivessel disease has been studied in several recent studies with the purpose of defining the need, as well as the best moment to approach residual lesions. However, such studies included only stable patients. The best therapeutic approach to cardiogenic shock secondary to acute coronary syndrome, however, remains controversial, but there are recommendations from specialists for revascularization that include non-event related injuries. Recently published, the CULPRIT-SHOCK study showed benefit of the initial approach only of the injury blamed for the acute event, in view of the multivessel percutaneous intervention, in the context of cardiogenic shock. In this perspective, the authors discuss the work in question, regarding methodological questions, limitations and clinical applicability.

Predictors of Outcomes in Myocardial Infarction and Cardiogenic Shock

Myocardial infarction (MI) complicated by cardiogenic shock (MI-CS) is a major cause of cardiovascular morbidity and mortality. Predictors of outcomes in MI-CS include clinical, laboratory, radiologic variables, and management strategies. This article reviews the existing literature on short- and long-term predictors and risk stratification in MI complicated by CS.

Cardiogenic Shock: Recent Developments and Significant Knowledge Gaps

PURPOSE OF REVIEW

Patients with cardiogenic shock (CS) continue to have high rates of morbidity and mortality. We aimed to describe current principles in the management of CS including coronary revascularization, medical management, mechanical circulatory support, and supportive care.

RECENT FINDINGS

Revascularization is still recommended, but trials have not found a benefit in the revascularization of nonculprit artery lesions. New mechanical circulatory support options are available, but optimal use remains uncertain. Overall improvement in outcomes appears to have plateaued. There remain substantial knowledge gaps about the management of CS. The ideal timing and selection criteria for mechanical support remain under-developed. There has been little systematic study to inform medical management or supportive care of this patient population. A more expansive research focus is necessary to improve the care of CS.