Mechanical Circulatory Support for Advanced Heart Failure

Clinicopathological correlations in heart transplantation recipients complicated by death or re-transplantation

Purpose

This study aimed to identify and correlate pathological findings with clinical outcomes in patients after orthotopic heart transplantation (OHT) who either died or underwent a re-transplantation.

Methodology and study design

Single-center retrospective analysis of primary OHT patients who died or were re-transplanted between October 2012 and July 2021. Clinical data were matched with corresponding pathological findings from endomyocardial biopsies on antibody-mediated rejection, cellular rejection, and cardiac allograft vasculopathy. Re-assessment of available tissue samples was performed to investigate acute myocardial injury (AMI) as a distinct phenomenon. These were correlated with clinical outcomes, which included severe primary graft dysfunction. Patients were grouped according to the presence of AMI and compared.

Results

We identified 47 patients with truncated outcomes after the first OHT. The median age was 59 years, 36 patients (76%) were male, 25 patients (53%) had a prior history of cardiac operation, and 21 patients (45%) were supported with a durable assist device before OHT. Of those, AMI was identified in 22 (47%) patients (AMI group), and 25 patients had no AMI (non-AMI group). Groups were comparable in baseline and perioperative data. Histopathological observations in AMI group included a non-significant higher incidence of antibody-mediated rejection Grade 1 or higher (pAMR ≥ 1) (32% vs. 12%, P = 0.154), and non-significant lower incidence of severe acute cellular rejection (ACR ≥ 2R) (32% vs. 40%, P = 0.762). Clinical observations in the AMI group found a significantly higher occurrence of severe primary graft dysfunction (68% vs. 20%, P = 0.001) and a highly significant shorter duration from transplantation to death or re-transplantation (42 days [IQR 26, 120] vs. 1,133 days [711–1,664], P < 0.0001). Those patients had a significantly higher occurrence of cardiac-related deaths (64% vs. 24%, P = 0.020). No difference was observed in other outcomes.

Conclusion

In heart transplant recipients with a truncated postoperative course leading to either death or re-transplantation, AMI in endomyocardial biopsies was a common pathological phenomenon, which correlated with the clinical occurrence of severe primary graft dysfunction. Those patients had significantly shorter survival times and higher cardiac-related deaths. The presence of AMI suggests a truncated course after OHT.

Baseline QRS duration associates with cardiac recovery in patients with continuous-flow left ventricular assist device implantation

Objective

In chronic heart failure (HF) patients supported with continuous-flow left ventricular assist device (CF-LVAD), we aimed to assess the clinical association of pre-LVAD QRS duration (QRSd) with post-LVAD cardiac recovery, and its correlation with pre- to post-LVAD change in left ventricular ejection fraction (LVEF) and left ventricular end-diastolic diameter (LVEDD).

Methods

Chronic HF patients (n = 402) undergoing CF-LVAD implantation were prospectively enrolled, at one of the centers comprising the U.T.A.H. (Utah Transplant Affiliated Hospitals) consortium. After excluding patients with acute HF etiologies, hypertrophic or infiltrative cardiomyopathy, and/or inadequate post-LVAD follow up (<3 months), 315 patients were included in the study. Cardiac recovery was defined as LVEF ≥ 40 % and LVEDD < 6 cm within 12 months post-LVAD implantation. Patients fulfilling this condition were termed as responders (R) and results were compared with non-responders (NR).

Results

Thirty-five patients (11 %) achieved 'R' criteria, and exhibited a 15 % shorter QRSd compared to 'NR' (123 ± 37 ms vs 145 ± 36 ms; p < 0.001). A univariate analysis identified association of baseline QRSd with post-LVAD cardiac recovery (OR: 0.986, 95 % CI: 0.976-0.996, p < 0.001). In a multivariate logistic regression model, after adjusting for duration of HF (OR: 0.990, 95 % CI: 0.983-0.997, p = 0.006) and gender (OR: 0.388, 95 % CI: 0.160-0.943, p = 0.037), pre-LVAD QRSd exhibited a significant association with post-LVAD cardiac structural and functional improvement (OR: 0.987, 95 % CI: 0.977-0.998, p = 0.027) and the predictive model showed a c-statistic of 0.73 with p < 0.001. The correlations for baseline QRSd with pre- to post-LVAD change in LVEF and LVEDD were also investigated in 'R' and 'NR' groups.

Conclusion

Chronic advanced HF patients with a shorter baseline QRSd exhibit an increased potential for cardiac recovery after LVAD support.

Risk of Stroke with Impella Placement Is Not Associated with Access Vessel

Objective: The Impella heart pump is an intravascular microaxial device that provides short-term mechanical circulatory support and can be placed through the femoral, axillary, or central vessels. One of the most feared complications is stroke. It is unclear if patient stroke risk varies based on access vessel. Methods: A retrospective review of consecutive patients who underwent Impella placement at an academic institution from January 1, 2007, through September 15, 2018, was performed. Four groups were compared: (1) minimally invasive Impella (femoral or axillary access), (2) minimally invasive Impella upgraded to another minimally invasive Impella, (3) minimally invasive Impella upgraded to a central Impella (ascending aorta), and (4) central Impella. Patient charts were reviewed to identify baseline characteristics. Outcome measures included length of stay, stroke, and mortality. Results: A total of 349 patients (or 407 Impellas) were identified, and the majority of the devices were inserted through a minimally invasive approach (n = 248, 60.9%), while the remainder were implanted via central access (n = 159, 39.1%). Minimally invasive Impellas were upgraded in 44 patients. The risk of stroke for the entire cohort was 10.3% (n = 36), with no difference observed in any particular group. Overall mortality was 44.4% (n = 155). Of the patients who initially received a minimally invasive Impella, those who were upgraded had higher rates of mortality (56.8% vs 39.4%, P = 0.03), postoperative dialysis (50.0% vs 27.4%, P < 0.01), and sepsis (43.2% vs 20.0%, P < 0.01). Conclusions: This study found no statistically significant difference in rates of postoperative stroke based on initial access vessel.

Currently Available Options for Mechanical Circulatory Support for the Management of Cardiogenic Shock

Cardiogenic shock (CS) is a complex condition with a high risk for morbidity and mortality. Mechanical circulatory support (MCS) devices were developed to support patients with CS in cases refractory to treatment with vasoactive medications. Current devices include intra-aortic balloon pumps, intravascular microaxial pumps, percutaneous LVAD, percutaneous RVAD, and VA ECMO. Data from limited observational studies and clinical trials show a clear difference in the level of hemodynamic support offered by each device. However, at this point, there are insufficient clinical trial data to guide MCS selection and, until ongoing clinical trials are completed, use of the right device for the right patient depends largely on clinical judgment.

Successful establishment of a left ventricular assist device program in an emerging country: one year experience

Background

The primary goal of this study was to evaluate the outcomes of patients with end-stage heart failure (HF) who underwent continuous flow left ventricular assist device (CF-LVAD) in a developing country and to compare to those reported by more developed countries. The secondary goal was on determining factors that may be connected to improved survival.

Methods

We prospectively analyzed 47 consecutive patients who underwent CF-LVAD at our institution. After one year the survival and adverse event profiles of patients were evaluated. At 3, 6 and 12 months, the cardiac, renal and liver function outcomes were assessed.

Results

The 30-day, 6-month and 1-year survival rates were 89%, 85% and 80%, respectively. A significant improvement in dimensions and ejection fraction of left ventricle, BNP, functional capacity, blood urea nitrogen (BUN) and total bilirubin (P<0.05 for all) were noticed 3 months post-CF-LVAD implantation, and patients were stable throughout the entire first year follow up. In the group of patients with baseline renal dysfunction (RD) there were significant improvements of renal function (P=0.004), with no changes on follow up. 57% of patients exhibited some kind of adverse event, commonly in the form of bleeding. In multivariate Cox regression analysis renal failure was found to be as an independent risk factor for the overall survival (HR =13.1, P<0.001).

Conclusions

In conclusion, our data extends previous findings from centers of developed countries, that CF-LVAD is an adequate treatment option for patients suffering from end-stage HF, and encourages expansion of CF-LVAD implantation in developing countries with nascent HT program.

Current Status of Left Ventricular Assist Device Therapy

Congestive heart failure (HF) remains a serious burden in the Western World. Despite advances in pharmacotherapy and resynchronization, many patients have progression to end-stage HF. These patients may be candidates for heart transplant or left ventricular assist device (LVAD) therapy. Heart transplants are limited by organ shortages and in some cases by patient comorbidities; therefore, LVAD therapy is emerging as a strategy of bridge to transplant or as a destination therapy in patients ineligible for transplant. Patients initially ineligible for a transplant may, in certain cases, become eligible for transplant after physiologic improvement with LVAD therapy, and a small number of patients with an LVAD may have sufficient recovery of myocardial function to allow device explantation. This clinically oriented review will describe (1) the most frequently used pump types and aspects of the continuous-flow physiology and (2) the clinical indications for and the shift toward the use of LVADs in less sick patients with HF. Additionally, we review complications of LVAD therapy and project future directions in this field. We referred to the Interagency Registry for Mechanically Assisted Circulatory Support, landmark trials, and results from recently published studies as major sources in obtaining recent outcomes, and we searched for related published literature via PubMed. This review focuses primarily on clinical practice for primary care physicians and non-HF cardiologists in the United States.

Patient selection for advanced heart failure therapy referral

Despite advances in medical therapy for chronic heart failure (HF), advanced HF carries a dismal prognosis. Options such as transplantation and durable mechanical circulatory support have greatly improved outcomes for these patients, but their introduction has introduced significant complexity to patient management. Although much of this management occurs at specialized heart transplant centers, it is the responsibility of the primary cardiologist of the patient with advanced HF to refer patients at the appropriate time and to help them navigate the difficult decisions related to the pursuit of advanced therapies. We present a unique pathway that incorporates guidelines, recent data, and expert opinion to help general cardiologists determine which patients should be referred for transplantation or durable mechanical circulatory support, and when they should be referred. Decision making on referral to the heart transplant center is also summarized.

Medical management of patients with continuous-flow left ventricular assist devices

OPINION STATEMENT

The prevalence of patients living with advanced heart failure continues to rise. For a subset of these patients, continuous-flow left ventricular assist devices (LVADs) are a life-saving therapy. Given the efficacy and durability of contemporary LVAD devices, their use has increased exponentially in recent years. The medical management of patients with an LVAD is an area of expertise for advanced heart failure clinicians, but a general understanding of the initial approach to, and stabilization of, LVAD patients is an important skillset for many health care providers. The rapidly changing field of the medical management of LVAD patients is largely based on clinical experience and limited published data. In this manuscript, we integrate the available published data on the medical management of LVAD patients with the growing clinical experience.

Heart failure while on ventricular assist device support: a true clinical entity?

Ventricular assist devices (VADs) have become an established therapeutic option for patients with end-stage heart failure. The appearance of heart failure in VAD patients seems unexpected. Nevertheless, this phenomenon is not rare. We report six cases of VAD patients with clinical presentation of heart failure at different times after implantation and describe the mechanisms involved. The aetiology of this heart failure, like its clinical presentation, varies and has yet to be identified.

Update on the Management of Acute Decompensated Heart Failure

OPINION STATEMENT: Treatment goals of acute decompensated heart failure are to decrease congestion, afterload, and neurohormonal activation in order to improve hemodynamics and symptoms and, perhaps, reduce in-hospital events, re-hospitalizations, and mortality while avoiding toxicities of therapy such as hypotension, arrhythmias, and renal dysfunction. Relief of congestion through intravenous loop diuretics is a mainstay of therapy. In cases where diuretics are not effective, ultrafiltration may be used to achieve euvolemia. Beta-blockers should be continued or reduced in dose at admission but should not typically be held. In patients with normotensive or hypertensive heart failure, afterload reduction with vasodilators should be instituted at presentation. Choice of a particular agent such as nitroglycerin, nitroprusside, or nesiritide depends on patient characteristics such as presence of ischemia, degree of congestion, and renal function. Nitroprusside may be preferable in patients with congestion and low cardiac output, but with caution in patients with significant hypotension. Intravenous inotropes/inodilators, such as dobutamine and milrinone, should be limited to hypotensive patients with evidence of poor tissue perfusion. Milrinone may be preferable in patients who have significant pulmonary venous hypertension. In patients who do not respond to initial medical therapy and who are candidates for either cardiac transplantation or destination left ventricular assist device, mechanical circulatory support should be considered early, prior to the development of end-organ damage.