D. Ramzy

Subclinical leaflet thrombosis in surgical and transcatheter bioprosthetic aortic valves: an observational study

BACKGROUND Subclinical leaflet thrombosis of bioprosthetic aortic valves after transcatheter valve replacement (TAVR) and surgical aortic valve replacement (SAVR) has been found with CT imaging. The objective of this study was to report the prevalence of subclinical leaflet thrombosis in surgical and transcatheter aortic valves and the effect of novel oral anticoagulants (NOACs) on the subclinical leaflet thrombosis and subsequent valve haemodynamics and clinical outcomes on the basis of two registries of patients who had CT imaging done after TAVR or SAVR. METHODS Patients enrolled between Dec 22, 2014, and Jan 18, 2017, in the RESOLVE registry, and between June 2, 2014, and Sept 28, 2016, in the SAVORY registry, had CT imaging done with a dedicated four-dimensional volume-rendered imaging protocol at varying intervals after TAVR and SAVR. We defined subclinical leaflet thrombosis as the presence of reduced leaflet motion, along with corresponding hypoattenuating lesions shown with CT. We collected data for baseline demographics, antithrombotic therapy, and clinical outcomes. We analysed all CT scans, echocardiograms, and neurological events in a masked fashion. FINDINGS Of the 931 patients who had CT imaging done (657 [71%] in the RESOLVE registry and 274 [29%] in the SAVORY registry), 890 [96%] had interpretable CT scans (626 [70%] in the RESOLVE registry and 264 [30%] in the SAVORY registry). 106 (12%) of 890 patients had subclinical leaflet thrombosis, including five (4%) of 138 with thrombosis of surgical valves versus 101 (13%) of 752 with thrombosis of transcatheter valves (p=0·001). The median time from aortic valve replacement to CT for the entire cohort was 83 days (IQR 33-281). Subclinical leaflet thrombosis was less frequent among patients receiving anticoagulants (eight [4%] of 224) than among those receiving dual antiplatelet therapy (31 [15%] of 208; p<0·0001); NOACs were equally as effective as warfarin (three [3%] of 107 vs five [4%] of 117; p=0·72). Subclinical leaflet thrombosis resolved in 36 (100%) of 36 patients (warfarin 24 [67%]; NOACs 12 [33%]) receiving anticoagulants, whereas it persisted in 20 (91%) of 22 patients not receiving anticoagulants (p<0·0001). A greater proportion of patients with subclinical leaflet thrombosis had aortic valve gradients of more than 20 mm Hg and increases in aortic valve gradients of more than 10 mm Hg (12 [14%] of 88) than did those with normal leaflet motion (seven [1%] of 632; p<0·0001). Although stroke rates were not different between those with (4·12 strokes per 100 person-years) or without (1·92 strokes per 100 person-years) reduced leaflet motion (p=0·10), subclinical leaflet thrombosis was associated with increased rates of transient ischaemic attacks (TIAs; 4·18 TIAs per 100 person-years vs 0·60 TIAs per 100 person-years; p=0·0005) and all strokes or TIAs (7·85 vs 2·36 per 100 person-years; p=0·001). INTERPRETATION Subclinical leaflet thrombosis occurred frequently in bioprosthetic aortic valves, more commonly in transcatheter than in surgical valves. Anticoagulation (both NOACs and warfarin), but not dual antiplatelet therapy, was effective in prevention or treatment of subclinical leaflet thrombosis. Subclinical leaflet thrombosis was associated with increased rates of TIAs and strokes or TIAs. Despite excellent outcomes after TAVR with the new-generation valves, prevention and treatment of subclinical leaflet thrombosis might offer a potential opportunity for further improvement in valve haemodynamics and clinical outcomes. FUNDING RESOLVE (Cedars-Sinai Heart Institute) and SAVORY (Rigshospitalet).

Bariatric Surgery in Severe Obesity and End-stage Heart Failure With Mechanical Circulatory Support as a Bridge to Successful Heart Transplantation: A Case Report

We present the first report of the concurrent use of mechanical circulatory support and bariatric surgery in a morbidly obese patient as a bridge to successful heart transplantation. The concurrent use of mechanical circulatory support and bariatric surgery allowed the patient to lose weight and subsequently to qualify for placement on the heart transplant waiting list. This strategy supports consideration of patients previously deemed unsuitable for heart transplantation owing to morbid obesity. Careful patient selection and strict monitoring of the immunosuppressive regimens are important considerations for a favorable outcome.

Combined Heart and Liver Transplantation: The Cedars-Sinai Experience

PURPOSE Combined heart-liver transplantation is an increasingly accepted treatment for select patients with heart and liver disease. Despite growing optimism, heart-liver transplantation remains an infrequent operation. We report our institutional experience with heart-liver transplantation. METHODS All combined heart-liver transplantations at Cedars-Sinai Medical Center from 1998-2014 were analyzed. Primary outcomes were patient and graft survival and secondary outcomes included rejection, infection, reoperation, length of stay, and readmission. RESULTS There were 7 heart-liver transplants: 6 simultaneous (single donor) and 1 staged (2 donors). Median follow-up was 22.1 (IQR 13.2-48.4) months. Mean recipient age was 50.8 ± 19.5 years. Heart failure etiologies included familial amyloidosis, congenital heart disease, hypertrophic cardiomyopathy, systemic lupus erythematosus, and dilated cardiomyopathy. Preoperative left ventricular ejection fraction averaged 32.3 ± 12.9%. Five (71.4%) patients required preoperative inotropic support; 1 required mechanical circulatory support. The most common indications for liver transplant were amyloidosis and cardiac cirrhosis. Median Model for End-stage Liver Disease score was 10.0 (9.3-13.8). Six-month and 1-year actuarial survivals were 100% and 83.3%, with mean survival exceeding 4 years. No patient experienced cardiac allograft rejection, 1 experienced transient liver allograft rejection, and 1 developed progressive liver dysfunction resulting in death. Five developed postoperative infections and 3 (42.9%) required reoperation. Median ICU and hospital stays were 7.0 (7.0-11.5) and 17.0 (13.8-40.5) days. There were 4 (57.1%) readmissions. CONCLUSIONS For carefully selected patients with coexisting heart and liver disease, combined heart and liver transplantation offers acceptable patient and graft survival.

Heart Transplantation With and Without Prior Sternotomy: Analysis of the United Network for Organ Sharing Database

INTRODUCTION Patients with history of prior sternotomy may have poorer outcomes after heart transplantation. Quantitation of risk from prior sternotomy has not been well established. The United Network for Organ Sharing (UNOS) database was analyzed to assess early and late survival and predictors of outcome in adult heart transplant recipients with and without prior sternotomy. METHODS Of 11,266 adults with first heart-only transplantation from 1997 to 2011, recipients were divided into 2 groups: those without prior sternotomy (first sternotomy group; n = 6006 or 53.3%) and those with at least 1 prior sternotomy (redo sternotomy group; n = 5260 or 46.7%). A multivariable Cox model was used to identify predictors of mortality. RESULTS Survival was lower in the redo group at 60 days (92.6% vs 95.9%; hazard ratio [HR] 1.83, 95% confidence interval [CI]: 1.56-2.15; P < .001). Conditional 5-year survival in 60-day survivors was similar in the 2 groups (HR = 1.01, 95% CI 0.90-1.12, P = .90). During the first 60 days post-transplant, the redo group had more cardiac reoperations (12.3% vs 8.8%, P = .0008), a higher frequency of dialysis (8.9% vs 5.2%, P < .0001), a greater percentage of drug-treated infections (23.2% vs 19%, P = .003), and a higher percentage of strokes (2.5% vs 1.4%, P = .0001). A multivariable Cox proportional hazards model identified prior sternotomy as a significant independent predictor of mortality, in addition to age, female gender, congenital cardiomyopathy, need for ventilation, mechanical circulatory support, dialysis prior to transplant, pretransplant serum bilirubin (≥ 3 mg/dL), and preoperative serum creatinine (≥ 2 mg/dL). CONCLUSIONS Prior sternotomy is associated with an excess 3.3% mortality and higher morbidity within the first 60 days after heart transplantation, as measured by frequency of dialysis, drug-treated infections, and strokes. Conditional 5-year survival after 60 days is unaffected by prior sternotomy. These findings should be taken into account for risk assessment of patients undergoing heart transplantation.

Massive Pulmonary Embolism: Extracorporeal Membrane Oxygenation and Surgical Pulmonary Embolectomy

Abstract Massive pulmonary embolism (PE) refers to large emboli that cause hemodynamic instability, right ventricular failure, and circulatory collapse. According to the 2016 ACCP Antithrombotic Guidelines, therapy for massive PE should include systemic thrombolytic therapy in conjunction with anticoagulation and supportive care. However, in patients with a contraindication to systemic thrombolytics or in those who fail the above interventions, extracorporeal membrane oxygenation (ECMO) and/or surgical embolectomy may be used to improve oxygenation, achieve hemodynamic stability, and successfully treat massive PE. Randomized controlled human trials evaluating ECMO in this context have not been done, and its role has not been well‐defined. The European Society of Cardiology 2014 acute PE guidelines briefly mention that ECMO can be used for massive PE as a method for hemodynamic support and as an adjunct to surgical embolectomy. The 2016 CHEST Antithrombotic Therapy for venous thromboembolism Disease guidelines do not mention ECMO in the management of massive PE. However, multiple case reports and small series cited benefit with ECMO for massive PE. Further, ECMO may facilitate stabilization for surgical embolectomy. Unfortunately, ECMO requires full anticoagulation to maintain the functionality of the system; hence, significant bleeding complicates its use in 35% of patients. Contraindications to ECMO include high bleeding risk, recent surgery or hemorrhagic stroke, poor baseline functional status, advanced age, neurologic dysfunction, morbid obesity, unrecoverable condition, renal failure, and prolonged cardiopulmonary resuscitation without adequate perfusion of end organs. In this review, we discuss management of massive PE, with an emphasis on the potential role for ECMO and/or surgical embolectomy.

Adult Heart Transplantation Following Ventricular Assist Device Implantation: Early and Late Outcomes

PURPOSE The impact of prior implantation of a ventricular assist device (VAD) on short- and long-term postoperative outcomes of adult heart transplantation (HTx) was investigated. METHODS Of the 359 adults with prior cardiac surgery who underwent HTx from December 1988 to June 2012 at our institution, 90 had prior VAD and 269 had other (non-VAD) prior cardiac surgery. RESULTS The VAD group had a lower 60-day survival when compared with the Non-VAD group (91.1% ± 3.0% vs 96.6% ± 1.1%; P = .03). However, the VAD and Non-VAD groups had similar survivals at 1 year (87.4% ± 3.6% vs 90.5% ± 1.8%; P = .33), 2 years (83.2% ± 4.2% vs 88.1% ± 2.0%; P = .21), 5 years (75.7% ± 5.6% vs 74.6% ± 2.9%; P = .63), 10 years (38.5% ± 10.8% vs 47.6% ± 3.9%; P = .33), and 12 years (28.9% ± 11.6% vs 39.0% ± 4.0%; P = .36). The VAD group had longer pump time and more intraoperative blood use when compared with the Non-VAD group (P < .0001 for both). Postoperatively, VAD patients had higher frequencies of >48-hour ventilation and in-hospital infections (P = .0007 and .002, respectively). In addition, more VAD patients had sternal wound infections when compared with Non-VAD patients (8/90 [8.9%] vs 5/269 [1.9%]; P = .005). Both groups had similar lengths of intensive care unit (ICU) and hospital stays and no differences in the frequencies of reoperation for chest bleeding, dialysis, and postdischarge infections (P = .19, .70, .34, .67, and .21, respectively). Postoperative creatinine levels at peak and at discharge did not differ between the 2 groups (P = .51 and P = .098, respectively). In a Cox model, only preoperative creatinine ≥1.5 mg/dL (P = .006) and intraoperative pump time ≥210 minutes (P = .022) were individually considered as significant predictors of mortality within 12 years post-HTx. Adjusting for both, pre-HTx VAD implantation was not a predictor of mortality within 12 years post-HTx (hazard ratio [HR], 1.23; 95% confidence interval [CI], 0.77-1.97; P = .38). However, pre-HTx VAD implantation was a risk factor for 60-day mortality (HR, 2.86; 95% CI, 1.07-7.62; P = .036) along with preoperative creatinine level ≥2 mg/dL (P = .0006). CONCLUSIONS HTx patients with prior VAD had lower 60-day survival, higher intraoperative blood use, and greater frequency of postoperative in-hospital infections when compared with HTx patients with prior Non-VAD cardiac surgery. VAD implantation prior to HTx did not have an additional negative impact on long-term morbidity and survival following HTx. Long-term (1-, 2-, 5-, 10-, and 12-year) survival did not differ significantly in HTx patients with prior VAD or non-VAD cardiac surgery.

Intermediate Outcomes with Ex-Vivo Allograft Perfusion for Heart Transplantation

BACKGROUND The Organ Care System, an ex-vivo heart perfusion platform, represents an alternative to the current standard of cold organ storage that sustains the donor heart in a near-physiologic state. It is unknown whether using the Organ Care System influences 2-year outcomes after heart transplantation. We reviewed our institutional experience to compare 2-year outcomes for patients randomized to the Organ Care System or standard cold storage. METHODS Between 2011 and 2013, heart transplant candidates from a single tertiary-care medical center enrolled within the PROCEED II trial were randomized to either standard cold storage or the Organ Care System. Outcomes assessed included 2-year survival, freedom from cardiac allograft vasculopathy (CAV), non-fatal major cardiac events (NF-MACE), biopsy-proven cellular rejection (CMR) and biopsy-proven antibody-mediated rejection (AMR). RESULTS Thirty-eight patients were randomized to the Organ Care System (n = 19) or cold storage group (n = 19). There was no significant difference in 2-year patient survival (Organ Care System: 72.2%; cold storage: 81.6%; p = 0.38). Similarly, there were no differences in freedom from CAV, NF-MACE, CMR or AMR. The Organ Care System group had significantly longer total ischemia time (361 ± 96 minutes vs 207 ± 50 minutes; p < 0.001) and shorter cold ischemia time (134 ± 45 minutes vs 207 ± 50 minutes; p < 0.001) compared with the cold storage group. CONCLUSION The Organ Care System did not appear to be associated with significant differences in intermediate results compared with conventional strategies. These results suggest that this ex-vivo allograft perfusion system is a promising and valid platform for donor heart transportation.

Coronary artery bypass graft surgery using the radial artery as a secondary conduit improves patient survival.

Background The clinical benefits of the left internal thoracic artery–to–left anterior descending coronary artery graft are well established in coronary artery bypass graft surgery (CABG). However, limited data are available regarding the long‐term outcome of the radial artery (RA) as a secondary conduit over the established standard of the saphenous venous graft. Methods and Results We compared the 12‐year survival outcome in a set of propensity‐matched CABG patients who received either the RA or the saphenous vein as a secondary conduit. A multivariable logistic regression that included 18 baseline characteristics was used to define the propensity of receiving an RA graft. The propensity model resulted in 260 matched pairs who underwent first‐time isolated CABG from 1996 to 2001 with similar preoperative characteristics (C statistic=0.86). The cumulative 12‐year survival estimated by use of the Kaplan–Meier method was higher for the RA graft patients (hazard ratio 0.76; P=0.03). This survival advantage was especially significant in diabetics (P=0.005), in women (P=0.02), and in the elderly (P=0.04.) The protective effect appeared beginning at year 5 post surgical intervention. Conclusion The RA as a secondary conduit provided superior long‐term survival after CABG, especially in diabetic patients, women, and the elderly. This effect was most pronounced >5 years after surgery.

Device Strategies for Patients in INTERMACS Profiles 1 and 2 Cardiogenic Shock: Double Bridge With Extracorporeal Membrane Oxygenation and Initial Implant of More Durable Devices

For Interagency Registry for Mechanically Assisted Circulatory Support profiles 1 and 2 cardiogenic shock patients initially placed on extracorporeal membrane oxygenation (ECMO), whether crossover to more durable devices is associated with increased survival, and its optimal timing, are not established. Profiles 1 and 2 patients placed on mechanical support were prospectively registered. Survival and successful hospital discharge were compared between patients placed on ECMO only, ECMO with early crossover, and ECMO with delayed crossover. Survival of patients directly implanted with non-ECMO devices was also reported. One-hundred and sixty-two patients were included. Mean age was 52.2 ± 13.8 years. Seventy-three of 162 (45.1%) were initiated on ECMO. Of these, 43 were supported with ECMO only, 11 were crossed-over early <4 days, and 19 were crossed-over in a delayed fashion. Survival was different across groups (Log-rank P < 0.002). In multivariate analysis, early crossover was associated with decreased mortality as compared with no crossover (hazard ratio [HR] 0.201, 95% confidence interval [95%CI] 0.058-0.697, P = 0.011) or with delayed crossover (HR 0.255, 95%CI 0.073-0.894, P = 0.033). Mortality was not different between delayed crossover and no crossover (P = 0.473). In patients with early crossover there were no deaths at 30 days, and 60-day survival was 90.0 ± 9.5%. Survival to hospital discharge was 72.8%. For patients directly implanted with non-ECMO devices, 30-day and 60-day survival was 90.9 ± 3.1% and 87.3 ± 3.8%, respectively, and survival to hospital discharge was 78.7%. Both initial implant of durable devices and double bridge strategy was associated with improved outcomes. If the double bridge strategy is chosen, early crossover is associated with improved survival and successful hospital discharge.

Prior sternotomy increases the mortality and morbidity of adult heart transplantation.

BACKGROUND This study investigated the effect of prior sternotomy (PS) on the postoperative mortality and morbidity after orthotopic heart transplantation (HTx). METHODS Of 704 adults who underwent HTx from December 1988 to June 2012 at a single institution, 345 had no PS (NPS group) and 359 had ≥ 1 PS (PS group). Survival, intraoperative use of blood products, intensive care unit (ICU) and hospital stays, frequency of reoperation for bleeding, dialysis, and >48-hour ventilation were examined. RESULTS The NPS and PS groups had similar 60-day survival rates (97.1 ± 0.9% vs 95.3 ± 1.1%; P = .20). However, the 1-year survival was higher in the NPS group (94.7 ± 1.2% vs 89.7 ± 1.6%; hazard ratio [HR], 1.98; 95% CI, 1.12-3.49; P = .016). The PS group had longer pump time and more intraoperative blood use (P < .0001 for both). Postoperatively, the PS group had longer ICU and hospital stays, and higher frequencies of reoperation for bleeding and >48-hour ventilation (P < .05 for all comparisons). Patients with 1 PS (1PS group) had a higher 60-day survival rate than those with ≥ 2 PS (2+PS group; 96.7 ± 1.1% vs 91.1 ± 3.0%; HR, 2.70; 95% CI, 1.04-7.01; P = .033). The 2+PS group had longer pump time and higher frequency of postoperative dialysis (P < .05 for both). Patients with prior VAD had lower 60-day (91.1 ± 3.0% vs 97.1 ± 0.9%; P = .010) and 1-year (87.4 ± 3.6% vs 94.7 ± 1.2%; P = .012) survival rates than NPS group patients. Patients with prior CABG had a lower 1-year survival than NPS group patients (89.0 ± 2.3% vs 94.7 ± 1.2%; P = .018). CONCLUSION The PS group had lower 1-year survival and higher intraoperative blood use, postoperative length of ICU and hospital stays, and frequency of reoperation for bleeding than the NPS group. Prior sternotomy increases morbidity and mortality after HTx.