Comparison of survival and other complications after heart transplantation in patients taking amiodarone before surgery versus those not taking amiodarone

Preoperative Amiodarone and Primary Graft Dysfunction in Heart Transplantation

BACKGROUND

Preoperative amiodarone effects on postorthotopic heart transplant (OHT) outcomes remain controversial.

OBJECTIVE

The purpose of this study was to determine the effect of cumulative pre-OHT amiodarone exposure on severe primary graft dysfunction (PGD).

METHODS

We retrospectively reviewed adult OHT recipients between August 2012 and June 2018. Primary outcome was severe PGD in patients receiving amiodarone at 3, 6, and 12 months prior to OHT compared with those not receiving amiodarone. Secondary outcomes included intensive care unit (ICU) and hospital length of stay, duration of mechanical ventilation, early graft failure (EGF), mortality at 3, 6, and 12 months post-OHT, and 30-day incidence of postoperative tachyarrhythmias, bradycardia, permanent pacemaker implantation, and rejection.

RESULTS

Incidence of severe PGD was 12.5% in those who received amiodarone compared to 6.8% in those who did not (14 vs 6, P = 0.18). Cumulative preoperative amiodarone significantly increased the odds of severe PGD at 3 months (odds ratio [OR]: 1.03; 95% confidence interval [CI]: 1.001-1.06; P = 0.044) and 6 months (OR: 1.02, 95% CI: 1.003-1.044; P = 0.024) in a multivariate logistic regression. Patients on amiodarone had significantly higher rates of postoperative bradycardia (13.4% vs 4.5%, P = 0.03).

CONCLUSION AND RELEVANCE

A trend toward increased PGD was present in patients receiving preoperative amiodarone. This finding combined with the regression showing significantly increased odds of PGD with increasing 3 and 6 month cumulative amiodarone dose is clinically concerning. Escalation of care with pacemaker implantation was required more frequently in patients on pre-OHT amiodarone.

Management of Arrhythmias After Heart Transplant: Current State and Considerations for Future Research

Orthotropic heart transplantation remains the most effective therapy for patients with end-stage heart failure, with a median survival of ≈13 years. Yet, a number of complications are observed after orthotropic heart transplantation, including atrial and ventricular arrhythmias. Several factors contribute to arrhythmias, such as autonomic denervation, effect of the surgical technique, acute and chronic rejection, and transplant vasculopathy among others. To minimize risk of future arrhythmias, the bicaval technique and minimizing ischemic time are current surgical standards. Sinus node dysfunction is the most common indication for early (within 30 days) pacemaker implantation, whereas atrioventricular block incidence increases as time from transplant increases. Atrial fibrillation can occur in the first few weeks following transplantation but is uncommon in the long term unless secondary to a precipitant such as acute rejection. The most common atrial arrhythmias are atrial flutters, which are mainly typical, but atypical circuits can be observed such as those that involve the remnant donor atrium in regions immediately adjacent to the atrioatrial anastomosis suture line. Choosing the appropriate pharmacological therapy requires careful consideration due to the potential interaction with immunosuppressive agents. Despite historical concerns, adenosine is effective and safe at reduced doses if administered under cardiac monitoring. Catheter ablation has emerged as an effective treatment strategy for symptomatic supraventricular tachycardias, including ablation of atypical flutter circuits. Cardiac allograft vasculopathy is an important risk factor for sudden cardiac death, yet the role of prophylactic implantable cardioverter-defibrillator implant for sudden death prevention is unclear. Current indications for implantable cardioverter-defibrillator implantation are as in the nontransplant population. A number of questions for future research are posed.

Amiodarone Use Prior to Cardiac Transplant Impacts Early Post-Transplant Survival

PURPOSE

It remains unclear if use of amiodarone pre-cardiac transplantation impacts early post-transplant survival.

METHODS

We selected all patients undergoing heart transplant from 2004 to 2006 with available information using the United Network for Organ Sharing database (n = 4057). Multivariable Cox models compared the risk of death within 30 days post-transplant in patients who were taking amiodarone at the time of transplant listing (n = 1227) to those who were not (n = 2830).

RESULTS

Mean age was 52 (± 12) years, and 23% were women. Patients who died within 30 days (n = 168) were older; had higher panel reactive antibody levels, higher bilirubin levels, and higher prevalence of prior cardiac surgery; were often at status 1B; and had higher use of amiodarone at listing compared to those who survived (5.3% versus 3.6%; p = 0.02). Cause of death was unknown in 49% and was reported as graft failure in 43% of cases. In multivariable Cox models, patients on amiodarone at the time of listing had 1.56-fold higher risk of post-transplant death within 30 days (95% confidence intervals 1.08-2.27) compared to patients who were not on amiodarone at listing (C-statistic 0.70).

CONCLUSION

In conclusion, patients who reported taking amiodarone at the time of listing for transplant had a higher risk of death within 30 days post-transplant.

Combined amiodarone and digitalis therapy before heart transplantation is associated with increased post-transplant mortality

Aims

Amiodarone and digitalis are frequently used drugs in patients with heart failure. Both have separately been linked to reduced post‐transplant survival, but their combined impact on mortality after HTX remains uncertain. This study investigated the effects of combined amiodarone and digitalis use before HTX on post‐transplant outcomes.

Methods and results

This registry study analysed 600 patients receiving HTX at Heidelberg Heart Center between 1989 and 2016. Patients were stratified by amiodarone and digitalis use before HTX. Analysis included patient characteristics, medication, echocardiographic features, heart rates, permanent pacemaker implantation, atrial fibrillation, and post‐transplant survival including causes of death. One hundred eighteen patients received amiodarone before HTX (19.7%), hereof 67 patients with digitalis (56.8%) and 51 patients without digitalis before HTX (43.2%). Patients with and without amiodarone before HTX showed a similar 1 year post‐transplant survival (72.0% vs. 78.4%, P = 0.11), but patients with combined amiodarone and digitalis before HTX had a worse 1 year post‐transplant survival (64.2%, P = 0.01), along with a higher percentage of death due to transplant failure (P = 0.03). Echocardiographic analysis of these patients showed a higher percentage of an enlarged right ventricle (P = 0.02), left atrium (P = 0.02), left ventricle (P = 0.03), and a higher rate of reduced left ventricular ejection fraction (P = 0.03). Multivariate analysis indicated combined amiodarone and digitalis use before HTX as a significant risk factor for 1 year mortality after HTX (hazard ratio: 1.69; 95% confidence interval: 1.02–2.77; P = 0.04).

Conclusions

Combined pre‐transplant amiodarone and digitalis therapy is associated with increased post‐transplant mortality.

Clinical and procedural characteristics predicting need for chronotropic support and permanent pacing post-heart transplantation

BACKGROUND

Postoperative bradycardia can complicate orthotopic heart transplantation (OHT). Previous studies suggested donor age and surgical technique as possible risk factors. However, risk factors in the era of bicaval anastomosis have not been elucidated.

OBJECTIVE

We sought to examine the association between donor/recipient characteristics with need for chronotropic support and permanent pacemaker (PPM) implantation in patients with OHT.

METHODS

All patients treated with OHT between January 2003 and January 2018 at the Hospital of the University of Pennsylvania were retrospectively evaluated until June 2018. Chronotropic support was given upon postoperative inability to increase the heart rate to patient's demands and included disproportionate bradycardia and junctional rhythm.

RESULTS

A total of 820 patients (mean age 51.3 ± 12.6 years; 607, 74% men) underwent 826 OHT procedures (787 patients, 95.3% bicaval anastomosis). Patients who were exposed to amiodarone (odds ratio [OR] 2.30; 95% confidence interval [CI] 1.58-3.34; P < .001) and have older donor (OR 1.02; 95% CI 1.01-1.04; P = .001) were more likely to develop need for chronotropic support. In multivariable analysis, recipient age (OR 1.03; 95% CI 1.00-1.06; P = .04) and biatrial anastomosis (OR 6.12; 95% CI 2.48-15.09) were significantly associated with PPM implantation within 6 months of OHT. No association was found between pre-OHT amiodarone use and PPM implantation. No risk factors assessed were associated with PPM implantation 6 months post-OHT.

CONCLUSION

Surgical technique and donor age were the main risk factors for the need for chronotropic support post-OHT, whereas surgical technique and recipient age were risk factors for early PPM implantation.

Primary graft dysfunction after heart transplantation: Incidence, trends, and associated risk factors

Changes in heart transplantation (HT) donor and recipient demographics may influence the incidence of primary graft dysfunction (PGD). We conducted a retrospective study to evaluate PGD incidence, trends, and associated risk factors by analyzing consecutive adult patients who underwent HT between January 2009 and December 2014 at our institution. Patients were categorized as having PGD using the International Society for Heart & Lung Transplantation (ISHLT)-defined criteria. Variables, including clinical and demographic characteristics of donors and recipients, were selected to assess their independent association with PGD. A time-trend analysis was performed over the study period. Three-hundred seventeen patients met inclusion criteria. Left ventricular PGD, right ventricular PGD, or both, were observed in 99 patients (31%). Risk factors independently associated with PGD included ischemic time, recipient African American race, and recipient amiodarone treatment. Over the study period, there was no change in the PGD incidence; however, there was an increase in the recipient pretransplantation use of amiodarone. The rate of 30-day mortality was significantly elevated in those with PGD versus those without PGD (6.06% vs 0.92%, P = .01). Despite recent advancements, incidence of PGD remains high. Understanding associated risk factors may allow for implementation of targeted therapeutic interventions.

Comparison of posttransplant outcomes in patients with no, acute, or chronic amiodarone use before heart transplantation

Background

Major concerns about the safety of pretransplant amiodarone use have been raised. As a result of its long half-life, the cardiac allograft is exposed to amiodarone posing potential risks such as bradycardia, requirement for pacemaker implantation, or increased mortality after heart transplantation (HTX).

Objective

The aim of this study is to investigate the posttransplant outcomes of patients with no, acute, or chronic amiodarone use before HTX.

Methods

This retrospective single-center study included 530 adult patients who received HTX between 06/1989 and 12/2012. Patients were stratified by their amiodarone therapy before HTX: no continuous amiodarone use (≤90 days before HTX), acute amiodarone use (≤90 days before HTX), and chronic amiodarone use (>90 days before HTX). Differences between the 3 groups in demographics, posttransplant medication, echocardiographic features, heart rates including occurrences of bradycardia, permanent pacemaker implantation, atrial fibrillation (AF), and survival were analyzed.

Results

A total of 412 patients (77.7%) were in the “no amiodarone” group, 23 patients (4.4%) in the “acute amiodarone” group, and 95 patients (17.9%) in the “chronic amiodarone” group. Left ventricular ejection fraction (P=0.5819), heart rates including occurrence of bradycardia during posttransplant week 1 (P=0.0979 and P=0.2695), week 2 (P=0.1214 and P=0.8644), week 3 (P=0.1033 and P=0.8894), and week 4 (P=0.2892 and P=0.8644), permanent pacemaker implantation within 30-day (P=0.8644), or overall follow-up after HTX (P=0.8664) were not significant between groups. Patients with chronic pretransplant amiodarone therapy had the lowest rate of early posttransplant AF (P=0.0065). There was no statistically significant difference between groups in 30-day (P=0.8656), 1-year (P=1.0000), 2-year (P=0.8763), 5-year (P=0.5174), or overall posttransplant follow-up mortality (P=0.1936).

Conclusion

Administration of acute or chronic pretransplant amiodarone was not related to an increased occurrence of bradycardia, requirement for permanent pacemaker implantation, or mortality after HTX. Importantly, chronic amiodarone use effectively reduced early AF after HTX, whereas acute amiodarone use showed no such effect.

Pre-cardiac transplant amiodarone use is not associated with postoperative mortality: An updated meta-analysis

BACKGROUND

Amiodarone remains the preferred agent for the treatment and prevention of life-threatening ventricular arrhythmias in patients with end-stage heart failure. While several reports suggest that pre-operative amiodarone exposure worsens outcomes in heart transplant recipients, other studies have failed to validate this relationship. We sought to clarify this issue by performing a meta-analysis of the available literature surrounding this topic.

METHODS

We searched Medline, SCOPUS and the Cochrane Central Register of Controlled Trials through December 15th 2016, as well as proceedings from related conferences over the prior 3years. Included studies evaluated patients undergoing cardiac transplantation who had received pre-transplant amiodarone and reported postoperative mortality. Outcomes were pooled using a Hartung-Knapp random-effects model producing odds ratios (OR) and 95% confidence intervals (CI). Statistical heterogeneity was evaluated using the Cochrane Q statistic p-value and I² value. Publication bias was assessed by visual inspection of funnel plots and using Egger's weighted regression statistic.

RESULTS

Nine studies including 16,509 participants were included in the overall analysis. Use of pre-transplant amiodarone was not associated with an increase in postoperative mortality versus control (OR 1.38, 95% 0.8 to 2.36). Moderate statistical heterogeneity was present (I²=45.8%, p=0.06); visual inspection of funnel plot analysis did not suggest publication bias. No association was noted between a longer duration of follow-up and higher odds of mortality with amiodarone use (p=0.91).

CONCLUSION

Meta-analysis of the available evidence suggests that pre-operative amiodarone exposure does not increase mortality in cardiac transplant recipients.

Amiodarone use in patients listed for heart transplant is associated with increased 1-year post-transplant mortality

BACKGROUND

Pre-transplant amiodarone use has been postulated as a risk factor for morbidity and mortality after orthotopic heart transplantation (OHT). We assessed pre-OHT amiodarone use and tested the hypothesis that it is associated with impaired post-OHT outcomes.

METHODS

We performed a retrospective cohort analysis of adult OHT recipients from the registry of the International Society for Heart and Lung Transplantation (ISHLT). All patients had been transplanted between 2005 and 2013 and were stratified by pre-OHT amiodarone use. We derived propensity scores using logistic regression with amiodarone use as the dependent variable, and assessed the associations between amiodarone use and outcomes with Kaplan-Meier analysis after matching patients 1:1 based on propensity score, and with Cox regression with adjustment for propensity score.

RESULTS

Of the 14,944 OHT patients in the study cohort, 32% (N = 4,752) received pre-OHT amiodarone. Amiodarone use was higher in recent years (29% in 2005 to 2007, 32% in 2008 to 2010, 35% in 2011 to 2013). Amiodarone-treated patients were older and more frequently had a history of sudden cardiac death (27% vs 13%) and pre-OHT mechanical circulatory support. Key donor characteristics and allograft ischemia times were similar between groups. In propensity-matched analyses, amiodarone-treated patients had higher rates of cardiac reoperation (15% vs 13%) and permanent pacemaker (5% vs 3%) after OHT and before discharge. Amiodarone-treated patients also had higher 1-year mortality (hazard ratio 1.15, 95% confidence interval 1.02 to 1.30), but the risks of early graft failure, retransplantation and rehospitalization were similar between groups.

CONCLUSIONS

Amiodarone use before OHT was independently associated with increased 1-year mortality. The need for amiodarone therapy should be carefully and continuously assessed in patients awaiting OHT.

To use or not to use? Amiodarone before heart transplantation

BACKGROUND

Amiodarone frequently is used in patients with heart failure. Concerns still exist about possible complications related to its lingering effect during and after heart transplantation.

METHODS

We selected all consecutive patients who received a heart transplant at our institution between January 2004 and December 2015 (n = 220) and compared the peri- and postoperative outcomes of patients who were taking amiodarone for at least 120 days before heart transplant (n = 127) with patients who did not take amiodarone prior to heart transplant (n = 93).

RESULTS

Compared with patients with no amiodarone use prior to transplant, those who had used amiodarone were similar in age, body mass index, sex, cause of cardiomyopathy, prevalence of diabetes, hypertension, presence of defibrillator, and had similar donor ischemic times during transplant (all P > .05). Median operative time, aortic cross clamp time, mechanical ventilation and median hospital duration of stay did not differ between the 2 groups (P > .05). Patients exposed to amiodarone had fewer cellular rejections (5% vs 20%; P = .001) but more primary graft dysfunction (4% vs 0%; P = .025) and post-transplant pneumonia (P = .047) compared with patients not taking amiodarone prior to transplant. Both groups had similar rate of atrial fibrillation, 30-day readmission, and 30-day mortality (P > .05). Even though 1-year survival was not affected by amiodarone use (P = .51), long-term (5-year) survival was significantly less in patients exposed to amiodarone (P = .03).

CONCLUSION

Amiodarone use did not affect the incidence of atrial fibrillation nor 30-day and 1-year survival post-transplantation. Nevertheless, post-transplant pulmonary complications were significantly greater and 5-year survival was less among patients treated with amiodarone prior to transplant.

Impact of pre-implant amiodarone exposure on outcomes in cardiac transplant recipients

Amiodarone remains one of the preferred antiarrhythmic medications for patients with advanced heart failure awaiting cardiac transplant. However, the long half-life and rapid redistribution of this agent into donor myocardium expose heart transplant recipients to potential adverse outcomes. In reviewing the current body of literature, we found that pre-operative amiodarone exposure can increase the risk of bradycardia post-transplant; however, this is unlikely to require permanent pacemaker implant. Further, amiodarone has several serious drug-drug interactions with calcineurin inhibitors. Clinicians should therefore consider empiric reduction in initial dosing for tacrolimus or cyclosporine, and carefully monitor blood levels for at least 3 months post-transplant. Although the evidence is conflicting, amiodarone exposure pre-operatively may increase the risk of early graft failure and mortality. Amiodarone use should be minimized whenever possible; if amiodarone cannot practically be discontinued in the pre-transplant phase, judicious monitoring for QTc prolongation and ventricular arrhythmia should be implemented after transplant. As most of the studies included in this review suffered from small sample sizes and limited follow-up, additional research in this area is warranted.

Long-term use of amiodarone before heart transplantation significantly reduces early post-transplant atrial fibrillation and is not associated with increased mortality after heart transplantation

Background

Amiodarone is a frequently used antiarrhythmic drug in patients with end-stage heart failure. Given its long half-life, pre-transplant use of amiodarone has been controversially discussed, with divergent results regarding morbidity and mortality after heart transplantation (HTX).

Aim

The aim of this study was to investigate the effects of long-term use of amiodarone before HTX on early post-transplant atrial fibrillation (AF) and mortality after HTX.

Methods

Five hundred and thirty patients (age ≥18 years) receiving HTX between June 1989 and December 2012 were included in this retrospective single-center study. Patients with long-term use of amiodarone before HTX (≥1 year) were compared to those without long-term use (none or <1 year of amiodarone). Primary outcomes were early post-transplant AF and mortality after HTX. The Kaplan–Meier estimator using log-rank tests was applied for freedom from early post-transplant AF and survival.

Results

Of the 530 patients, 74 (14.0%) received long-term amiodarone therapy, with a mean duration of 32.3±26.3 months. Mean daily dose was 223.0±75.0 mg. Indications included AF, Wolff–Parkinson–White syndrome, ventricular tachycardia, and ventricular fibrillation. Patients with long-term use of amiodarone before HTX had significantly lower rates of early post-transplant AF (P=0.0105). Further, Kaplan–Meier analysis of freedom from early post-transplant AF showed significantly lower rates of AF in this group (P=0.0123). There was no statistically significant difference between patients with and without long-term use of amiodarone prior to HTX in 1-year (P=0.8596), 2-year (P=0.8620), 5-year (P=0.2737), or overall follow-up mortality after HTX (P=0.1049). Moreover, Kaplan–Meier survival analysis showed no statistically significant difference in overall survival (P=0.1786).

Conclusion

Long-term use of amiodarone in patients before HTX significantly reduces early post-transplant AF and is not associated with increased mortality after HTX.

Total Thyroidectomy for Amiodarone-associated Thyrotoxicosis in Patients with Severe Cardiac Disease

BACKGROUND

Surgical treatment of amiodarone-associated thyrotoxicosis (AAT) is effective although fewer than 100 cases have been reported world wide.

MATERIALS AND METHODS

We reviewed 14 patients treated with total thyroidectomy by a single surgeon from 1998 to 2005.

RESULTS

There were 11 male and 3 female patients who ranged in age from 26 to 82 years (average 50.5). Nine patients refractory to medical management and 5 in whom amiodarone needed to be continued were treated surgically. Ten patients developed thyrotoxicosis while being treated with amiodarone, but 4 became thyrotoxic after ceasing amiodarone 2, 2, 6 and 13 months previously. One patient recently had a cardiac transplant, and 4 were on the active cardiac transplant waiting list. Cardiac ejection fractions ranged from 15% to 50% (average 39%). Four patients had serious complications from medication used to control thyrotoxicosis, including one case of agranulocytosis from carbimazole. Total thyroidectomy was performed under general anaesthesia with no significant intraoperative complications and no deaths. There were no recurrent laryngeal nerve injuries. Two patients required short-term calcium supplementation. All patients had rapid resolution of their symptoms and were euthyroid on thyroxine postoperatively. Two patients had such improvement they were removed from the cardiac transplant list.

CONCLUSIONS

Despite severe cardiac disease, total thyroidectomy can be performed successfully under general anaesthesia. Surgery should be considered early in the treatment plan. Surgery is particularly appropriate where it is considered necessary to continue amiodarone, when there are complications from the medications used to treat thyrotoxicosis and to facilitate fitness for or defer the need for cardiac transplantation.

Does Amiodarone Influence Early Mortality in Heart Transplantation?

The use of amiodarone before transplantation has been linked to an increased number of complications, acute graft failures, and early mortality after a heart graft. We undertook a retrospective, descriptive, case-controlled study involving early mortality and acute graft failure. The 396 consecutive patients included 25 subjects who had been prescribed amiodarone for at least 30 days before transplantation. We excluded retransplantations, pediatric transplantations, and combined transplantations. The endpoints were early mortality and acute graft failure. No significant differences were observed in early mortality and acute graft failures. The multivariate analysis did not reveal any variable that correlated with early mortality. Our study did not support the idea that amiodarone constituted a negative predictor of early survival or acute graft failure.