Left ventricular assist device as a bridge to surgery in postinfarction ventricular septal defect

Ventricular Septal Rupture After Myocardial Infarction: JACC Focus Seminar 3/5

Ventricular septal rupture remains a dreadful complication of acute myocardial infarction. Although less commonly observed than during the prethrombolytic era, the condition remains complex and is often associated with refractory cardiogenic shock and death. Corrective surgery, although superior to medical treatment, has been associated with high perioperative morbidity and mortality. Transcatheter closure techniques are less invasive to surgery and offer a valuable alternative, particularly in patients with cardiogenic shock. In these patients, percutaneous mechanical circulatory support represents a novel opportunity for immediate stabilization and preserved end-organ function. Multimodality imaging can identify favorable septal anatomy for the most appropriate type of repair. The heart team approach will define optimal timing for surgery vs percutaneous repair. Emerging concepts are proposed for a deferred treatment approach, including orthotropic heart transplantation in ideal candidates. Finally, for futile situations, palliative care experts and a medical ethics team will provide the best options for end-of-life clinical decision making.

Mechanical Circulatory Support as a Bridge to Definitive Treatment in Post-Infarction Ventricular Septal Rupture

Ventricular septal rupture (VSR) represents a rare complication of acute myocardial infarction, often presenting with cardiogenic shock and associated with high in-hospital mortality despite prompt intervention. Although immediate surgery is recommended for patients who cannot be effectively stabilized, the ideal timing of intervention remains controversial. Mechanical circulatory support (MCS) may allow hemodynamic stabilization and delay definitive treatment even in critical patients. However, the interactions between MCS and VSR pathophysiology as well as potentially related adverse effects remain unclear. A systematic review was performed, from 2000 onward, to identify reports describing MCS types, effects, complications, and outcomes in the pre-operative VSR-related setting. One hundred eleven studies (2,440 patients) were included. Most patients had well-known negative predictors (e.g., cardiogenic shock, inferior infarction). Almost all patients had intra-aortic balloon pumps, with additional MCS adopted in 129 patients (77.5% being venoarterial extracorporeal membrane oxygenation). Mean MCS bridging time was 6 days (range: 0 to 23 days). In-hospital mortality was 50.4%, with the lowest mortality rate in the extracorporeal membrane oxygenation group (29.2%). MCS may enhance hemodynamic stabilization and delayed VSR treatment. However, the actual effects and interaction of the MCS-VSR association should be carefully assessed to avoid further complications or incorrect MCS-VSR coupling.

Use of a Totally Artificial Heart for a Complex Postinfarction Ventricular Septal Defect

The incidence of cardiac rupture complicating myocardial infarction has declined since the introduction of thrombolytic therapy. Despite the advances in the management of myocardial infarction, cardiac rupture remains an important cause of death among infarction-related fatalities. We discuss a patient who presented to our hospital with myocardial infarction and who subsequently developed a complex ventricular septal rupture, for which surgical repair was not feasible. Implantation of a CardioWest Total Artificial Heart (SynCardia Systems) allowed for immediate hemodynamic stabilization and served as a bridge to transplantation.

Outcome and survival analysis of surgical repair of post-infarction ventricular septal rupture

Background

To review the experience of surgical repair of post-infarction ventricular septal rupture (VSR) and analyze the associated outcomes and prognostic factors.

Methods

Following approval from the Singhealth Centralised Institutional Review Board (reference: 2011/881/C), a retrospective review was performed on 38 consecutive patients who had undergone surgical repair of post-infarction VSR between 1999 and 2011. Continuous variables were expressed as either mean ± standard deviation or median with 25^th and 75^th percentiles. These were compared using two-tailed t-test or Mann–Whitney U test respectively. Categorical variables were compared using chi-square or Fisher’s exact test. To identify predictors of operative mortality, univariate analysis of perioperative variables followed by multivariate analysis of significant univariate risk factors was performed. A two-tailed p-value < 0.05 was used to indicate statistical significance.

Results

Mean age was 65.7 ± 9.4 years with 52.6% males. The VSR was anterior in 28 (73.7%) and posterior in 10 patients. Median interval from myocardial infarction to VSR was 1 day (1, 4). Pre-operative intra-aortic balloon pump was inserted in 37 patients (97.8%). Thirty-six patients (94.7%) underwent coronary angiography.

Thirty-five patients (92.1%) underwent patch repair. Mean aortic cross clamp time was 82 ± 40 minutes and mean cardiopulmonary bypass time was 152 ± 52 minutes. Coronary artery bypass grafting (CABG) was performed in 19 patients (50%), with a mean of 1.5 ± 0.7 distal anastomoses. Operative mortality within 30 days was 39.5%.

Univariate analysis identified emergency surgery, New York Heart Association (NYHA) class, inotropic support, right ventricular dysfunction, EuroSCORE II, intra-operative red cell transfusion, post-operative renal failure and renal replacement therapy (RRT) as predictors of operative mortality. Multivariate analysis identified NYHA class and post-operative RRT as predictors of operative mortality.

Ten year overall survival was 44.4 ± 8.4%. Right ventricular dysfunction, LVEF and NYHA class at presentation were independent factors affecting long-term survival. Concomitant CABG did not influence early or late survival.

Conclusions

Surgical repair of post-infarction VSR carries a high operative mortality. NYHA class at presentation and post-operative RRT are predictors of early mortality. Right ventricular dysfunction, LVEF and NYHA class at presentation affect long-term survival. Concomitant CABG does not improve survival.

Mechanical assistance of the circulation during cardiogenic shock

PURPOSE OF REVIEW

Cardiogenic shock still has a grave prognosis. We present the recent advances in mechanical circulatory support (MCS) for the treatment of refractory cardiogenic shock.

RECENT FINDINGS

The contraindications for short-term MCS in rapid-onset cardiogenic shock are becoming fewer and the threshold for its application has been progressively lowered. Short-term MCS is increasingly used in refractory cardiac arrest and will be probably integrated as the last means in the advanced cardiopulmonary resuscitation algorithm (provided there is experienced team and technical support). Improved device technology has contributed to improved results of long-term MCS. Emergent application of long-term MCS in patients with critical cardiogenic shock after a long history of progressively deteriorating end-stage chronic heart failure should be interpreted as delayed application associated with increased mortality.

SUMMARY

Although MCS can be life saving in cardiogenic shock, the results are still suboptimal. Mortality is associated with the critical presupport state and the adverse events during MCS. Early initiation of support that meets the patient's requirements, potent support in the early phase, adverse event prevention, global combined management (surgical, interventional, medical), balanced support duration, bridging to further therapeutic modalities including heart transplantation or longer-term support, and advanced technology could offer improved results.

Mechanical circulatory support in the ICCU

The mortality of acute heart failure (AHF) remains high despite advances in treatment. Mechanical circulatory support (MCS) can be applied in AHF, refractory to conventional measures, to improve outcomes. This article aims to describe the current and the prospective role of MCS in the treatment of AHF. The support strategies and the indications of MCS are continuously evolving, including situations considered as contraindications in the past. Appropriate patient selection, advanced device technology and improved patient management have contributed to the substantially improved results. Evolution in device technology results in evolution of the clinical applications of MCS. Earlier application of MCS, with novel, flexible and individualized support strategies is now feasible. Bridging to recovery is the most intriguing support strategy and bridging to future treatments is feasible with long-term support. The progressively expanding role of MCS in the treatment of heart failure is not reflected in the existing guidelines. Being reserved for refractory heart failure, MCS has been applied to the sickest patients who were less amenable to randomization. This explains the lack of robust evidence, but also highlights the value of the progressively improving results. The anticipated wider application of MCS should be better defined, systematically recorded, and guided.

Use of initial biventricular mechanical support in a case of postinfarction ventricular septal rupture as a bridge to surgery

The incidence of postinfarction ventricular septal rupture is declining as coronary revascularization techniques have become available for a large number of patients. However, morbidity and mortality rates associated with this complication remain high. We report the case of a patient suffering from acute myocardial infarction who developed a postinfarction ventricular septal defect. Instead of attempting surgical closure, he was placed on biventricular mechanical support. After 2 weeks, surgical closure of the defect and concomitant explantation of the assist device were successfully performed. This approach may represent a new treatment option restoring hemodynamic stability and avoiding surgery on freshly infarcted myocardium.

Update on ventricular assist device management in the ICU

PURPOSE OF REVIEW

Mechanical circulatory support has a progressively increasing impact in the treatment of heart failure. The results of mechanical circulatory support are limited not only by the severity of the disease, which necessitated initiation of support, but also by the serious device-related adverse events. Optimized patient selection, improved patient management, and advanced device technology are interdependent key factors that contributed to the recently improved outcomes. The aim of this article is to summarize the current experience in application of mechanical circulatory support, focusing on the ICU management.

RECENT FINDINGS

Management should aim to prevent rather than treat serious complications and adverse events. Timing of intervention, optimization of the preimplantation patient status, patient and device management to ensure optimal hemodynamics, infection prevention, nutritional support, careful anticoagulation, and vigilance for early recognition and prompt treatment of 'minor' events before progression into major complications are essential elements of successful treatment.

SUMMARY

Critical patient care is a valuable adjunct to successful application of mechanical circulatory support, but it cannot counterbalance a late intervention, neither can it be fruitful in treating irreversible organ damage. Current management includes careful application of treatment protocols adjusted to recent experience, and also individualized care by a specialized team.