Mechanical bridge to recovery in fulminant myocarditis

Outcomes of Durable Mechanical Circulatory Support in Myocarditis: Analysis of the International Society for Heart and Lung Transplantation Registry for Mechanically Assisted Circulatory Support Registry

Myocarditis can be refractory to medical therapy and require durable mechanical circulatory support (MCS). The characteristics and outcomes of these patients are not known. We identified all patients with clinically-diagnosed or pathology-proven myocarditis who underwent mechanical circulatory support in the International Society for Heart and Lung Transplantation Registry for Mechanically Assisted Circulatory Support registry (2013-2016). The characteristics and outcomes of these patients were compared to those of patients with nonischemic cardiomyopathy (NICM). Out of 14,062 patients in the registry, 180 (1.2%) had myocarditis and 6,602 (46.9%) had NICM. Among patients with myocarditis, duration of heart failure was <1 month in 22%, 1-12 months in 22.6%, and >1 year in 55.4%. Compared with NICM, patients with myocarditis were younger (45 vs. 52 years, P < 0.001) and were more often implanted with Interagency Registry for Mechanically Assisted Circulatory Support profile 1 (30% vs. 15%, P < 0.001). Biventricular mechanical support (biventricular ventricular assist device [BIVAD] or total artificial heart) was implanted more frequently in myocarditis (18% vs. 6.7%, P < 0.001). Overall postimplant survival was not different between myocarditis and NICM (left ventricular assist device: P = 0.27, BIVAD: P = 0.50). The proportion of myocarditis patients that have recovered by 12 months postimplant was significantly higher in myocarditis compared to that of NICM (5% vs. 1.7%, P = 0.0003). Adverse events (bleeding, infection, and neurologic dysfunction) were all lower in the myocarditis than NICM. In conclusion, although myocarditis patients who receive durable MCS are sicker preoperatively with higher needs for biventricular MCS, their overall MCS survival is noninferior to NICM. Patients who received MCS for myocarditis are more likely than NICM to have MCS explanted due to recovery, however, the absolute rates of recovery were low.

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.

Mechanical Bridging to Improvement in Severe Acute 'Nonischemic, Nonmyocarditis' Heart Failure

Improved myocardial function has been observed in patients with acute myocarditis who have had short-term support with a ventricular assist system. Additionally, a limited number of patients with nonischemic cardiomyopathy have undergone successful device explantation after their myocardial function improved during ventricular assist system support. The authors present their experience with four patients who had acute, severe heart failure without coronary artery disease or biopsy-proven myocarditis. After receiving prolonged ventricular assist system support, all four patients had significantly improved left ventricular function, returning to New York Heart Association functional class I without inotropic therapy. In each case, dobutamine stress echocardiography and invasive hemodynamic tests were performed to confirm improvement of cardiac function before device explantation was undertaken. In all four cases, device explantation was followed by early successful maintenance of left ventricular function. These cases reveal a unique clinical syndrome that may be successfully treated with early institution of ventricular assist system support followed by explantation after myocardial recovery.

Ventricular assist devices as destination therapy

The prospects for long-term mechanical circulatory support are improving. Axial flow pumps are a promising competitor to pulsatile first-generation LVADs, although the two may serve different patient populations. Centrifugal pumps are in the development phase and seem to require less anticoagulation. Clinical experience has established the safety of diminished pulse pressure circulation, and mechanical unloading appears to promote recovery of the native left ventricle. Under these circumstances, true left ventricular assist is preferable to ventricular replacement and detailed medical management improves patient outcomes. Further clinical trials of destination therapy are indicated and must use more reliable blood pumps implanted before terminal decline into multiorgan failure.

Mechanical circulatory support for myocarditis: how much recovery should occur before device removal?

A 12-year-old girl with presumed myocarditis was supported with right and left ventricular assist devices for 68 days before device removal. During this time, the patient underwent echocardiography and right heart catheterization for evaluation of cardiac recovery. This case report serves as the basis for a discussion of criteria for deciding when to terminate mechanical circulatory support in a patient with recovery after acute myocarditis.

Left ventricular assist device as a bridge to recovery: present status

A new application for left ventricular assist devices (LVAD) is as a bridge to recovery. In the settings of myocarditis and dilated cardiomyopathy, LVAD support is accompanied by marked hemodynamic, neurohormonal, physiologic, cellular, and molecular changes indicative of recovery. Despite these changes, experience with clinical successes is limited. Further studies of topics such as the timing of LVAD implantation and explantation, adjunct medical and surgical therapy, and optimum LVAD weaning protocols might help improve the success of this promising technology.

Left ventricular dysfunction in children with fulminant enterovirus 71 infection: an evaluation of the clinical course

We describe 2 children with typical hand, foot, and mouth disease due to enterovirus 71 infection, 1 of whom died. Both cases were complicated by acute fulminant shock syndrome; the patients had remarkable acute left ventricular dysfunction. The clinical experience indicates that the rapid death associated with fulminant enterovirus rhombencephalitis is the result of rapid cardiogenic shock rather than neurogenic pulmonary edema.

Successful explantation of a ventricular assist device following fulminant influenza type A-associated myocarditis

We report a case of fulminant myocarditis associated with refractory ventricular fibrillation following influenza A infection. Histologic examination was consistent with myocarditis and serology confirmed the viral etiology. The patient was supported with biventricular assist devices for 20 days during which her refractory ventricular fibrillation resolved spontaneously. This is the first documented case of resolution of prolonged ventricular fibrillation while on a ventricular assist device. This case suggests those patients with fulminant viral myocarditis and refractory ventricular arrhythmias may be supported successfully with ventricular assist devices until myocardial recovery takes place.

Healing the heart with ventricular assist device therapy: mechanisms of cardiac recovery

As experience has grown with the use of mechanical circulatory support systems in patients with cardiogenic shock, many anecdotes have been noted where myocardial recovery occurred and devices could be removed with reasonable residual cardiovascular performance and resolution of the shock syndrome. Indeed, when first used, ventricular assist devices were inserted to bridge patients unable to be separated from cardiopulmonary bypass to eventual recovery. Many successes with ventricular support systems have been recorded in individuals with postcardiotomy cardiogenic shock, acute myocarditis, and in the periinfarction period where stunning of potentially viable myocardial tissue contributed to severe heart failure. From an experimental standpoint, recovery of myocyte function and restoration of more normal myocardial geometry and constitution have been noted. There are many explanations for this, but principally, benefit is related to amelioration of circulatory insufficiency with attenuation of perturbed humoral networks and reduction of myocardial wall stress. It is important to understand how ventricular assist device implantation in select advanced heart failure patients might precipitate recovery of depressed myocardial function.

Clinical results with the AB-180 left ventricular assist device

BACKGROUND

This report reviews the initial clinical experience with the AB-180 ventricular assist device.

METHODS

Between Dec 1997 and July 2000, the AB-180 was implanted in 17 patients at five institutions. The mean age was 52 years (range 21 to 68 years) and 14 of 17 were male. The indications for implantation were postcardiotomy shock (12 of 17, 70%), decompensated cardiomyopathy (2 of 17, 12%), viral myocarditis (2 of 17, 12%), and acute myocardial infarction (1 of 17, 6%).

RESULTS

The mean duration of support was 8.5 days (range 1 to 28 days). In the group of 17 patients, 8 were weaned from the device and 2 underwent transplantation. Four of the weaned patients (4 of 8, 50%) and 1 of the transplant patients (1 of 2, 50%) survived. The overall weaning and survival rates were 58% (10 of 17) and 29% (5 of 17). There were no major device-related complications and no major device malfunctions.

CONCLUSIONS

The AB-180 provides reliable circulatory support for reversible forms of heart failure.

Left ventricular assist device bridge to recovery: a review of the current status

The use of the left ventricular assist device as a bridge to recovery represents a new phenomenon. This article focuses on bridge-to-recovery in the settings of myocarditis and dilated cardiomyopathy with a review of the hemodynamic, neurohormonal, physiologic, cellular, and molecular changes of recovery during left ventricular assist device support. Despite numerous markers of success, there is a disconnect from the limited clinical successes that are reviewed. The current status and future options to increase the chances of success are highlighted.