Effect of Pretransplant Continuous-Flow Left Ventricular Assist Devices on Cellular and Antibody-Mediated Rejection and Subsequent Allograft Outcomes

The aim of this study was to evaluate the impact of continuous-flow left ventricular assist devices (CF-LVAD) on subsequent rejection after heart transplantation (HT) by using cellular rejection score and antibody-mediated rejection score (AMRS) and correlating with subsequent allograft outcomes. We retrospectively analyzed 108 consecutive patients who underwent HT without (n = 67) or with (n = 41) previous CF-LVAD in 2008 to 2014. The 24 months cumulative effect of rejection was calculated by using cellular rejection scores and AMRS, based on the total number of rejections divided by valid biopsy samples. Vasculopathy was assessed both by routine coronary angiogram and intravascular ultrasound. Patients who underwent pretransplant CF-LVAD demonstrated a significant increase in the number of cellular rejection episodes as compared with the nonbridged patients, for 1 and 2 years of follow-up (p = 0.026 and p = 0.016), respectively. There were no differences in AMRS (p >0.05) and allograft outcomes, such as vasculopathy and overall survival (p >0.05) over the period of follow-up. Implantation of a CF-LVAD before HT impacts cellular rejection during the post-transplant period. Despite these findings, CF-LVAD does not translate to differences in allograft outcomes after transplant, such as vasculopathy and overall survival over the period of the study. In conclusion, whether this affects longer term outcomes than studied remains to be determined.

Liver Allograft Provides Immunoprotection for the Cardiac Allograft in Combined Heart-Liver Transplantation

When transplanted simultaneously, the liver allograft has been thought to have an immunoprotective role on other organs; however, detailed analyses in simultaneous heart-liver transplantation (SHLT) have not been done to date. We analyzed patient outcomes and incidence of immune-mediated injury in 22 consecutive SHLT versus 223 isolated heart transplantation (IHT) recipients between January 2004 and December 2013, by reviewing 3912 protocol- and indication-specific cardiac allograft biopsy specimens. Overall survival was similar (86.4%, 86.4%, and 69.1% for SHLT and 93.3%, 84.7%, and 70.0% for IHT at 1, 5, and 10 years; p = 0.83). Despite similar immunosuppression, the incidence of T cell-mediated rejection (TCMR) was lower in SHLT (31.8%) than in IHT (84.8%) (p < 0.0001). Although more SHLT patients had preexisting donor-specific HLA antibody (22.7% versus 8.1%; p = 0.04), the incidence of antibody-mediated rejection was not different in SHLT compared with IHT (4.5% versus 14.8%, p = 0.33). While the left ventricular ejection fraction was comparable in both groups at 5 years, the incidence and severity of cardiac allograft vasculopathy were reduced in the SHLT recipients (42.9% versus 66.8%, p = 0.03). Simultaneously transplanted liver allograft was associated with reduced risk of TCMR (odds ratio [OR] 0.003, 95% confidence interval [CI] 0-0.02; p < 0.0001), antibody-mediated rejection (OR 0.04, 95% CI 0-0.46; p = 0.004), and cardiac allograft vasculopathy (OR 0.26, 95% CI 0.07-0.84; p = 0.02), after adjusting for other risk factors. These data suggest that the incidence of alloimmune injury in the heart allograft is reduced in SHLT recipients.

Heart transplantation after Fontan: Results from a surgical Fontan cohort

We performed a retrospective review of outcomes after heart transplantation during long-term follow-up of a surgical cohort of 1138 Fontan patients who were followed at the Mayo Clinic. Follow-up information was obtained from medical records and a clinical questionnaire that was mailed to patients not known to be deceased at the initiation of the study. Forty-four of 1138 Fontan patients with initial or subsequent evaluation at Mayo had cardiac transplantation between 1988 and 2014 (mean age at transplantation was 23.2 ± 12 yr, median was 19.8 yr; mean interval between Fontan and transplantation was 13.0 ± 7.7 yr, median was 13.1 yr). Two patients had combined organ transplantation (one heart-lung, one heart-liver). Twelve of the 44 (27%) patients had PLE prior to transplantation. There was no difference in post-bypass Fontan pressures or incidence of late reoperations for AVV repair/replacement between transplanted and non-transplanted patients. There were 16 (36%) deaths in the transplantation cohort; seven occurred within 30 days of transplantation. Overall one, five, 10, and 15 yr post-transplantation survival was 80%, 72%, 69%, and 55%, respectively. Although this is a challenging group of patients, intermediate-term results suggest that cardiac transplantation remains a reasonable option for patients with a failed Fontan circulation.

Left Internal Mammary Artery Versus Coronary Stents: Impact on Downstream Coronary Stenoses and Conduit Patency

BACKGROUND

The study compared downstream coronary and conduit disease progression in the left anterior descending coronary artery treated with coronary artery bypass grafting using the left internal mammary artery (LIMA) versus percutaneous coronary intervention with bare metal stent (BMS) or drug eluting stent (DES).

METHODS AND RESULTS

A total of 12 301 consecutive patients underwent isolated primary coronary revascularization, of which 2386 met our inclusion criteria (Percutaneous coronary intervention, n=1450; coronary artery bypass grafting, n=936). Propensity score analysis matched 628 patients, of which 468 were treated to the left anterior descending with coronary artery bypass grafting with LIMA (n=314), percutaneous coronary intervention with BMS (n=94), and DES (n=60). Coronary angiograms were analyzed by quantitative coronary angiography (QCA; n=433). Cumulative downstream coronary and conduit disease progression were estimated by Kaplan-Meier method and effect of treatment type by Cox proportional hazard models. Patients treated with LIMA had significantly lower risk of downstream coronary disease progression at follow-up angiogram compared with BMS and DES (hazard ratio [HR] [95% CI], 0.34; [0.20-0.59]; P=0.0002; and HR [95% CI], 0.39; [0.20-0.79]; P=0.01, respectively). LIMA was associated with a lower risk of conduit disease progression compared to BMS and DES (HR [95% CI], 0.18; [0.12-0.28]; P<0.001; and HR [95% CI], 0.27; [0.16-0.46]; P<0.001, respectively). BMS was associated with higher HR for downstream coronary and conduit disease progression compared with DES, but the difference did not reach statistical significance (HR [95% CI], 1.13; [0.57-2.36]; P=0.73; and HR [95% CI], 1.46; [0.88-2.50]; P=0.14, respectively).

CONCLUSIONS

LIMA grafting to left anterior descending is associated with significantly lower risk of downstream coronary and conduit disease progression compared to percutaneous coronary intervention with BMS and DES.

Kidney transplantation as a therapeutic option for end-stage renal disease developing after heart transplantation

BACKGROUND

Progressive renal failure is a frequent complication after heart transplantation (HTx). It may result in end-stage renal disease (ESRD), prompting consideration of kidney Tx after HTx (KAH).

METHODS

We performed a retrospective single-center study of 268 HTx recipients to evaluate outcomes after KAH compared with HTx recipients with and without ESRD.

RESULTS

During a median follow-up of 76 months, ESRD developed in 51 patients (19), and 39 of them (76%) underwent KAH. The mean time from HTx to ESRD was 83 months. The incidence of switching to a calcineurin inhibitor (CNI)-free regimen based on sirolimus was significantly lower among recipients with ESRD (6% vs 57%, p = 0.0001), and prolonged exposure to CNI significantly increased the risk for ESRD (hazard ratio, 1.09; 95% confidence interval, 1.03-1.15; p < 0.005). Death-censored renal graft survival after KAH was 95%, 95%, and 83% at 1, 5, and 10 years, respectively. Median long-term survival of KAH patients was comparable to HTx recipients without ESRD (17.5 vs 17.1 years, p = 0.27) and significantly better compared with HTx recipients with ESRD (17.5 vs 7.3 years, p < 0.001).

CONCLUSIONS

Prolonged exposure to CNI immunosuppression medications significantly increases the risk for ESRD among HTx recipients. KAH is a good therapeutic option for HTx recipients with ESRD, with survival benefit comparable to HTx without ESRD.

Postcardiotomy ECMO Support after High-risk Operations in Adult Congenital Heart Disease

BACKGROUND

Cardiac operations in high-risk adult congenital heart disease (ACHD) patients may require mechanical circulatory support (MCS), such as extracorporeal membrane oxygenation (ECMO) or intraaortic balloon pump (IABP), to allow the cardiopulmonary system to recover.

METHODS

We reviewed records for all ACHD patients who required MCS following cardiotomy at our institution from 1/2001 to 12/2013.

RESULTS

During the study period, 2264 (mean age 39.1 years, females ∼54.1%) operations were performed in ACHD patients of whom 24 (1.1%) required postoperative MCS (14 males; median age 41 years, range 22-75). Preoperatively the 24 patients had a mean systemic ventricular ejection fraction of 47% (range 10-66%); 72% of these patients were in NYHA class III/IV heart failure. The common underlying diagnoses included pulmonary atresia with intact ventricular septum (20%), tetralogy of Fallot (16%), Ebstein anomaly (12%), cc-TGA (12%), septal defects (12%), and others (28%). Operations performed were valvular operations with/without maze (58.2%), Fontan conversion (21%), coronary bypass grafting with valvular operations (12.5%), and heart transplant (8.3%). Indications for MCS were left-sided (systemic) heart failure (32%), right-sided (subpulmonary) heart failure (24%), biventricular heart failure (36%), persistent arrhythmia (4%), and hypoxemia (4%). Forty-two percent were placed on ECMO only; in the second group, IABP was attempted and subsequently followed by ECMO initiation. The mean duration of MCS was 8.4 days (range 0.8-35.4). Common morbidities included coagulopathy (60%), renal failure (56%), and arrhythmia (48%). Overall, 46% of patients survived to hospital discharge. Deaths were due to either multi organ failure or the underlying cardiac disease; sepsis was the primary cause of death in one patient. Median follow-up for survivors was 41 months (maximum 106 months). NYHA functional class was I/II in all 8 late survivors.

CONCLUSIONS

Following complex operations in high-risk ACHD patients, MCS may be required. Despite significant morbidity, nearly half of patients survive to hospital discharge.

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.

The Influence of Prior Median Sternotomy on Outcome of Heart Transplantation

This study is a retrospective analysis of the influence of previous cardiac surgery on the outcome of heart transplantation in 118 consecutive recipients from January 1988 to December 1996. Group 1 consisted of 67 patients who had no previous sternotomy, group 2 was 33 patients who had one previous sternotomy, and group 3 was 18 patients who had two or more previous sternotomies. The three groups were demographically similar apart from the indication for transplantation and the sex distribution. Preoperative hemodynamic data, except systolic pulmonary artery pressure, were similar among the three groups. There was no significant difference in hospital mortality, 1-year and 5-year actuarial survival rates, incidence of renal dysfunction requiring dialysis, prolonged respiratory support, elevated total bilirubin, re-exploration for bleeding, incidence of mediastinitis, or postoperative hospital stay between the groups. The rejection-free and infection-free survival rates were similar in the three groups. However, previous sternotomy resulted in significantly longer cardiopulmonary bypass times and increased requirement for blood and blood products. The use of a cell saver limited the need for stored red blood cells. This study demonstrated no survival disadvantage of previous sternotomy in patients undergoing heart transplantation.

Effect of Neurohormonal Blockade Drug Therapy on Outcomes and Left Ventricular Function and Structure After Left Ventricular Assist Device Implantation

Neurohormonal blockade drug therapy (NHBDT) is the cornerstone therapy in heart failure (HF) management for promoting reverse cardiac remodeling and improving outcomes. It's utility in left ventricular assist device (LVAD) supported patients remains undefined. Sixty-four patients who received continuous flow LVAD at our institution were retrospectively reviewed and divided into 2 groups: no-NHBDT group (n = 33) received LVAD support only and NHBDT group (n = 31) received concurrent NHBDT based on the clinical judgment of the attending physicians. Cardiac remodeling (echocardiographic parameters and biomarkers) and clinical outcome (functional status, HF-related hospital readmissions, and mortality) data were collected. A statistically significant increase in ejection fraction, decrease in LV end-diastolic diameter index and LV mass index, and a sustained reduction in N-terminal pro B-type natriuretic peptide (NTproBNP) were observed in the NHBDT group at 6 months after LVAD implant (p <0.05). NHBDT-treated patients experienced significantly greater improvement in New York Heart Association functional classification and 6-minute-walk distance throughout the study. The combined end point of cardiovascular death or HF hospitalization was significantly reduced in patients receiving NHBDT (p = 0.013) associated primarily with a 12.1% absolute reduction in HF-related hospitalizations (p = 0.046). In conclusion, NHBDT in LVAD-supported patients is associated with a significant reversal in adverse cardiac remodeling and a reduction in morbidity and mortality compared with LVAD support alone.

Association Between Early Cardiac Rehabilitation and Long-term Survival in Cardiac Transplant Recipients

OBJECTIVE

To determine whether participation in early cardiac rehabilitation (CR) after heart transplant (HTx) affects long-term survival.

PATIENTS AND METHODS

A retrospective review was conducted in 201 patients who underwent HTx at Mayo Clinic between June 1, 2000, and July 31, 2013. Patients were excluded with multiorgan transplant, no CR data, and follow-up less than 90 days after HTx. Demographic and exercise data at baseline before HTx were collected. Post-HTx exercise capacity, biopsy, CR data, and medications were collected at 1 through 5 and 10 years.

RESULTS

Overall survival at 1, 5, and 10 years was 98%, 88%, and 82%, respectively; 29 patients died. Number of CR sessions attended in the first 90 days after HTx predicted survival in multivariate regression, controlling for baseline post-HTx 6-minute walk test (6MWT) results and rejection episodes (hazard ratio, 0.90; 95% CI, 0.82-0.97; P=.007). Additional univariate predictors of survival included pre-HTx 6MWT results, weight at HTx, and body mass index and systolic blood pressure at CR enrollment. Pre-HTx 6MWT results, body mass index, and post-HTx were associated with improvement in peak oxygen consumption.

CONCLUSION

This report demonstrates, for the first time, an association between CR and long-term survival in patients after HTx. Further work should clarify the most beneficial aspects of CR.

Influence of Baseline Characteristics, Operative Conduct, and Postoperative Course on 30-Day Outcomes of Coronary Artery Bypass Grafting Among Patients With Left Ventricular Dysfunction: Results From the Surgical Treatment for Ischemic Heart Failure (STICH) Trial

BACKGROUND

Patients with severe left ventricular dysfunction, ischemic heart failure, and coronary artery disease suitable for coronary artery bypass grafting (CABG) are at higher risk for surgical morbidity and mortality. Paradoxically, those patients with the most severe coronary artery disease and ventricular dysfunction who derive the greatest clinical benefit from CABG are also at the greatest operative risk, which makes decision making regarding whether to proceed to surgery difficult in such patients. To better inform such decision making, we analyzed the Surgical Treatment for Ischemic Heart Failure (STICH) CABG population for detailed information on perioperative risk and outcomes.

METHODS AND RESULTS

In both STICH trials (hypotheses), 2136 patients with a left ventricular ejection fraction of ≤35% and coronary artery disease were allocated to medical therapy, CABG plus medical therapy, or CABG with surgical ventricular reconstruction. Relationships of baseline characteristics and operative conduct with morbidity and mortality at 30 days were evaluated. There were a total of 1460 patients randomized to and receiving surgery, and 346 (≈25%) of these high-risk patients developed a severe complication within 30 days. Worsening renal insufficiency, cardiac arrest with cardiopulmonary resuscitation, and ventricular arrhythmias were the most frequent complications and those most commonly associated with death. Mortality at 30 days was 5.1% and was generally preceded by a serious complication (65 of 74 deaths). Left ventricular size, renal dysfunction, advanced age, and atrial fibrillation/flutter were significant preoperative predictors of mortality within 30 days. Cardiopulmonary bypass time was the only independent surgical variable predictive of 30-day mortality.

CONCLUSIONS

CABG can be performed with relatively low 30-day mortality in patients with left ventricular dysfunction. Serious postoperative complications occurred in nearly 1 in 4 patients and were associated with mortality.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00023595.

Proximal thoracic aorta dimensions after continuous-flow left ventricular assist device implantation: Longitudinal changes and relation to aortic valve insufficiency

BACKGROUND

In this study we examined the impact of continuous-flow left ventricular assist device (CF-LVAD) support on proximal thoracic aorta dimensions.

METHODS

Aortic root and ascending aorta diameter were measured from serial echocardiograms before and after CF-LVAD implantation in patients with ≥6 months of support, and correlated with the development of >mild aortic valve insufficiency (AI).

RESULTS

Of 162 patients included, mean age was 58 ± 11 years and 128 (79%) were male. Seventy-nine (63%) were destination therapy patients. Mean aortic root and ascending aorta diameters at baseline, 1 month, 6 months, 12 months and long-term follow-up (mean 2.0 ± 1.4 years) were 3.5 ± 0.4, 3.5 ± 0.3, 3.9 ± 0.3, 3.9 ± 0.2 and 4.0 ± 0.3, and 3.3 ± 0.2, 3.3 ± 0.3, 3.6 ± 0.2, 3.6 ± 0.3 and 3.6 ± 0.3 cm, respectively. Only change in aortic root diameter from 1-month to 6-month follow-up reached statistical significance (p = 0.03). Nine (6%) patients had accelerated proximal thoracic aorta expansion (>0.5 cm/year), occurring predominantly in the first 6 months after implantation. These patients were older and more likely to have hypertension and baseline proximal thoracic aorta dilation. Forty-five (28%) patients developed >mild AI at long-term follow-up, including 7 of 9 (78%) of those with accelerated proximal thoracic aorta expansion. All 7 had aortic valves that remained closed throughout the cardiac cycle, and this, along with duration of CF-LVAD support and increase in aortic root diameter, were significantly associated with developing >mild AI.

CONCLUSION

CF-LVAD patients have small increases in proximal thoracic aorta dimensions that predominantly occur within the first 6 months after implantation and then stabilize. Increasing aortic root diameter was associated with AI development.

Robotic Mitral Valve Repair for Simple and Complex Degenerative Disease: Midterm Clinical and Echocardiographic Quality Outcomes

BACKGROUND

Severe primary (degenerative) mitral regurgitation (MR) is repaired with durable results when simple single-scallop disease is addressed. The midterm quality outcomes of minimally invasive repair for complex disease are unknown, however.

METHODS AND RESULTS

From January 2008 to January 2015, 487 patients (56±11 years, 360 men, ejection fraction 65±6%, 98.8% complete follow-up) underwent robotic mitral valve repair for severe nonischemic degenerative MR. Simple pathology was addressed in 289 of 487 (59%) patients, and complex repair (all others) was performed in 198 of 487 (41%). Four patients died during follow-up with a 5-year survival rate 99.5% (99.4% simple; 99.5% complex; hazard ratio, 0.48; 95% confidence interval, 0.05-4.59); and New York Heart Association functional class I/II was documented in 97.9% (477/487). Eight patients had recurrence of moderate-to-severe MR (4 simple, 4 complex), with a 5-year freedom from MR of 94.6% (96.2% simple; 92.7%, complex; P=0.67; hazard ratio, 1.36; 95% confidence interval, 0.34-5.43). Seven patients (2 simple, 5 complex), underwent mitral reoperation, with a 5-year freedom from reoperation of 97.7% (99.1% simple; 95.7% complex; P=0.13; hazard ratio, 3.35; 95% confidence interval, 0.65-17.32).

CONCLUSIONS

At a large tertiary care referral center, midterm quality outcomes after robotic correction of degenerative MR are excellent, with very high survival, infrequent complications, and a low likelihood of MR recurrence, regardless of mitral valve repair complexity. Awareness of these improvements in outcome is important to inform contemporary decisions regarding high-quality alternatives to conventional and percutaneous mitral repair.

How has robotic repair changed the landscape of mitral valve surgery?

The introduction of robotic technology has revolutionized the performance of certain cardiac surgical procedures such as mitral valve (MV) repair. The foundation of modern MV repair was laid by Dr. Dwight C. McGoon in 1958. The operation was first performed with robotic assistance by Carpentier in 1998 using rudimentary motion-assisted equipment. Today, four generations later, telemanipulation technology enables surgeons to carry out all known methods of MV repair traditionally performed by conventional sternotomy; utilizing tiny port access incisions to safely and reliably eliminate mitral regurgitation. Extubation in the operating room following robotic MV repair is now routine and its benefits are well-documented, including transfer to the step-down from the intensive care unit several hours after surgery. This, in turn, translates into diminished usage of blood products, decreased need for pain medication, earlier dismissal from hospital, more rapid return to work and improved patient satisfaction. In addition, smaller, more cosmetically appealing scars and comparable short and mid-term outcomes of robotic and open MV repair have made the robotic approach a preferred option for many patients who meet appropriate safety criteria. As these procedures become more commonplace in large structural heart practices, it is important to reflect upon how the robotic approach has changed the landscape of MV surgery. We discuss the evolution and current status of robotic MV repair founded upon the principles of safe and effective open mitral valvuloplasty techniques. We will explore the potential of the robotic platform to improve both early referral and patient acceptance of interventions to eliminate severe degenerative mitral regurgitation.

Cardiac Myxomas: A 50-Year Experience With Resection and Analysis of Risk Factors for Recurrence

BACKGROUND

Myxomas are the most common cardiac tumors, but there are insufficient data regarding long-term survival and recurrence rates. Our objective was to examine late results and attempt to determine a strategy for recurrence monitoring, as there are no recommended guidelines at present.

METHODS

We performed a retrospective analysis of 194 patients (mean age 57.2 ± 15.6 years; 62.4% female) undergoing resection of cardiac myxoma from June 1955 to June 2011. The left atrium (n = 155, 80%) was the most common location, and the mean tumor size was 4.3 ± 2.1 cm by 3.2 ± 1.6 cm by 2.1 ± 1.3 cm. Dyspnea (n = 68) and palpitations (n = 57) were the most common complaints, and 28 patients (14.4%) were asymptomatic.

RESULTS

The tumor was exposed through the respective atria in the majority of patients (n = 187). Bypass and cross-clamp times were 59.1 ± 33.4 minutes and 35.2 ± 21.7 minutes, respectively. Two thirds of the tumors were excised with an endocardial button, and the rest were resected at the base of the stalk. Operative mortality was 0.5%. Ten, 20 and 30-year survival was 77%, 52% and 34%, respectively, which was comparable to an age-matched general population (p = 0.191). Older age at operation was the only significant predictor of subsequent mortality (p < 0.001). There was no significant difference in survival when patients were stratified by sex (p = 0.784), location of tumor (p = 0.087), the largest tumor dimension (p = 0.257) or surgical technique (endocardial button versus base of the stalk, p = 0.502). Tumors recurred in 11 patients; freedom from tumor recurrence was 92%, 91%, and 86% at 10, 20, and 30 years, respectively. Younger age at surgery (hazard ratio 0.94, p = 0.002), smaller tumor dimension (hazard ratio 0.58, p = 0.011), and tumor localized to the ventricles (hazard ratio 7.29, p = 0.013) were predictors of recurrence.

CONCLUSIONS

Cardiac myxomas can be resected with low early mortality and excellent late survival. Tumor recurrence is more likely to occur in the first 10 postoperative years, especially in younger patients, patients with a smaller tumor mass, or tumor location in the ventricle. Patients with these findings require closer imaging surveillance in the first decade after resection.