Reactivation of Cytomegalovirus Following Left Ventricular Assist Device Implantation: A Case-Control Study

The Long-Term Survival of LVAD Patients-A TriNetX Database Analysis

Background: Donor shortage limits the utilization of heart transplantation, making it available for only a fraction of the patients on the transplant waiting list. Therefore, continuous-flow left ventricular assist devices (CF-LVADs) have evolved as a standard of care for end-stage heart failure. It is imperative therefore to investigate long-term survival in this population. Methods: This study assesses the impact of demographics, infections, comorbidities, types of cardiomyopathies, arrhythmias, and end-organ dysfunction on the long-term survival of LVAD recipients. The TriNetX database comprises de-identified patient information across healthcare organizations. The log-rank test assessed post-implant survival effects, while Cox regression was used in the univariate analysis to obtain the Hazard Ratio (HR). All analyses were conducted using the Python programming language and the lifelines library. Results: This study identified CMV, hepatitis A exposure, atrial fibrillation, paroxysmal ventricular tachycardia, ischemic cardiomyopathy, renal dysfunction, diabetes, COPD, mitral valve disease, and essential hypertension as risk factors that impact long-term survival. Interestingly, hypokalemia seems to have a protective effect and gender does not affect survival significantly. Conclusions: This is the first report of a detailed long-term survival assessment of the LVAD population using a decoded database.

Risk of Infections With Long-Term Left Ventricular Assist Device Support

The average life expectancy post-left ventricular assist device (LVAD) implantation has significantly increased in recent years. Impaired cellular immunity post-LVAD implantation has been suggested. It is not clear if a prolonged duration of LVAD support will lead to an increase in infections and possibly cause opportunistic infections, as seen in immunocompromised patients.

METHODS

 We retrospectively reviewed all the patients who underwent new continuous-flow (C-F) LVAD implantation between January 1, 2013, and December 31, 2014, at the University of Nebraska Medical Center. Patients were followed until heart transplant, LVAD explantation, death, or December 31, 2017. We defined LVAD infections as per the International Society of Heart and Lung Transplantation (ISHLT) definition: VAD-specific, VAD-related, and non-VAD infections. The primary outcome was to calculate the incidence of LVAD infections per 1000 days of LVAD support. Secondary outcomes were to assess the cause of death and the effect of bloodstream infections on LVAD thrombosis, stroke, and death.

RESULTS

During the study period, a total of 94 patients underwent a C-F LVAD implantation. Five patients were lost in follow-up; 89 patients were included in the study. The mean age at LVAD implantation was 54 (SD+15) years. Out of 89 patients, 67 (75%) were men, and 53/89 (71%) received LVAD as destination therapy (DT). At the time of LVAD implantation, 34/89 (38%) patients had ITERMACS (interagency registry for mechanically assisted circulatory support) score 1 (cardiogenic shock). The median duration of LVAD support was 387+493 days, with an interquartile range of 140 to 1083 days. The incidence rate of infections post-LVAD implantation decreased from 3.2 /1000 LVAD days (95% confidence interval [CI] 2.54-4.03) during the first year of LVAD support to 0.78/1000 LVAD days (95% CI, 0.38-1.65) during the following third year of LVAD support. Similarly, the incidence of VAD-specific infections in the first year post-LVAD implantation versus the third-year post LVAD implantation decreased from 0.83/1000 LVAD days (95% CI, 0.53-1.30) to 0.33/1000 LVAD days (95% CI, 0.10-1.04). On univariate survival analysis, an increased risk of death was associated with a one-year increase in age at LVAD implantation (hazard ratio (HR) 1.05 (95% CI, 1.01-1.09), p=0.01), the presence of infection within 30 days before LVAD implantation (HR 2.44 (95% CI, 1.09-5.48), p=0.03), underlying ischemic cardiomyopathy (HR 2.96 (95% CI, 1.28-6.80), p=0.01), and lower ITERMACS profile HR 3.64 (95% CI, 1.09-12.13, p=0.04). Bloodstream infections (BSIs) were not associated with an increased risk of death (HR 1.63 (95% CI, 0.56-4.80, p=0.37). Univariate survival analysis for poor outcomes (LVAD thrombosis, stroke, or death) showed BSIs increased the risk of having a poor outcome (HR 2.39 (95% CI, 1.02-5.57), p=0.04).

CONCLUSIONS

 The incidence rate of post-LVAD infections decreased significantly over time. LVAD implantation may not be contributing to immune suppression as previously suggested. In our study, BSIs were found to have a significantly increased hazard ratio for a poor outcome post-LVAD implantation.

Cytomegalovirus reactivation in left ventricular assist device patients: case series and literature review

Background 

Cytomegalovirus (CMV) reactivation after placing left ventricular assist device (LVAD) is not a well-known entity with few cases reported in the literature. Here, we are presenting three cases of CMV reactivation after placing LVAD. A literature review of all reported cases in the literature was done.

Case summary 

Three cases of advanced heart failure with reduced ejection fraction (Stage D9) had placed (LVAD) at the American University of Beirut Medical Center, a tertiary care centre in Lebanon. Within the first 2 weeks after LVAD implantation, the three patients spiked a high-grade fever for which sepsis workup was done, and antibiotics were initiated. Despite the escalating antibiotic regimens, the three patients had a persistent high-grade fever. The negative cultures and the continuous fever prompted an investigation for other causes of fever. Therefore, CMV polymerase chain reaction in blood was performed and revealed high titres. Patients received a full course of treatment with ganciclovir. The fever and the CMV titres declined after completing the antiviral therapy with better clinical outcomes. This raises the concern of CMV reactivation in LVAD patients.

Discussion 

This case series and literature review highlight the epidemiology, incidence, and management of CMV reactivation among LVAD patients. Awareness about this clinical entity should be raised, especially with the increase of LVAD surgeries.