Sara J. Shumway

Gastrointestinal bleeding rates in recipients of nonpulsatile and pulsatile left ventricular assist devices

OBJECTIVE Pulsatile and nonpulsatile left ventricular assist devices are effective in managing congestive heart failure. Despite early evidence for clinical efficacy, the long-term impact of nonpulsatile flow on end-organ function remains to be determined. Our goal was to compare rates of gastrointestinal bleeding in nonpulsatile and pulsatile device recipients. METHODS In a retrospective review of 101 left ventricular assist device recipients (55 nonpulsatile, 46 pulsatile) from October 31, 2003, to June 1, 2007, at a single center, gastrointestinal bleeding was defined as guaiac-positive stool with hemoglobin drop requiring transfusion of at least 2 units of packed red blood cells. To assess bleeding risk outside the initial postoperative course, any patients with a device in place for 15 days or less was excluded. RESULTS Twelve nonpulsatile and 3 pulsatile left ventricular assist device recipients had gastrointestinal bleeding 16 days or longer after device implantation. The event rates were 63 events/100 patient-years for nonpulsatile devices and 6.8 events/100 patient-years for pulsatile devices (P = .0004). This difference persisted for bleeding occurring 31 days or longer after device implantation, with 46.5 events/100 patient-years for nonpulsatile devices versus 4.7 events/100 patient-years for pulsatile devices (P = .0028). Mortalities were similar between groups (15% nonpulsatile vs 17% pulsatile, P = .6965). CONCLUSION Patients with nonpulsatile left ventricular assist devices appear to have a higher rate of gastrointestinal bleeding events than do pulsatile left ventricular assist device recipients. Further prospective evaluation is needed to determine potential etiologies and strategies for reducing gastrointestinal bleeding in this population.

Early and Late Airway Complications After Lung Transplantation: Incidence and Management

BACKGROUND Airway anastomosis complications continue to be a source of morbidity for lung transplant recipients. METHODS This study analyzes incidence, treatment, and follow-up of airway anastomotic complications occurring in 127 consecutive lung transplant airway anastomoses (77 single lung and 25 bilateral sequential lung). Complications were categorized as stenosis (11), granulation tissue (8), infection (7), bronchomalacia (5), or dehiscence (3). Follow-up after treatment ranged from 6 months to 4 years. RESULTS Nineteen airway anastomosis complications (15.0%) occurred in 18 patients. Telescoping the airway anastomosis reduced the complication rate to 12 of 97 (12.4%), compared with 7 of 30 (23.3%) for omental wrapping, (p = 0.15). Complications developed in 13 of 77 single-lung airway anastomoses (16.9%) versus 6 of 50 bilateral sequential lung recipients (12.0%). Treatment consisted of stenting (9 airway anastomoses), bronchodilation (8), laser debridement (4), rigid bronchoscopic debridement (2), operative revision (2), and growth factor application (2). There was no difference in actuarial survival between patients with or without airway anastomosis complications (p = 1.0). CONCLUSIONS Airway anastomosis complications can be successfully managed in the immediate or late postoperative period with good outcome up to 4 years after intervention.

Conservative management of postoperative chylothorax using somatostatin

Chylothorax is a rare but serious postoperative complication of thoracic surgical procedures. We report the case of a 77-year-old man who underwent a coronary artery bypass procedure using a left internal mammary artery pedicle graft. A permanent pacemaker was required postoperatively. A persistent postoperative chylothorax developed necessitating continuous drainage and conservative management. Somatostatin was instituted when after 1 week this management failed to resolve the chylothorax. This led to rapid cessation of chyle production. Enteral feeding was reinstituted without complication and surgical intervention was avoided.

Liberalization of donor criteria in lung and heart-lung transplantation

Since March 1986, we have performed 26 heart-lung transplantations, 42 single-lung transplantations, 9 bilateral single-lung transplantations, and 1 double-lung transplantation. The original lung donor requirements were as follows: age less than 40 years, no smoking history; no gram-negative rods or fungus on sputum Gram stain; arterial oxygen tension greater than 140 mm Hg on an inspired oxygen fraction of 0.40; no infiltrate or pneumothorax on the chest radiograph; and donor height within 15 cm (6 inches) of recipient height. As the number of potential recipients increased, so did the waiting time. To counter this delay, during the past year we have liberalized our donor criteria. We now accept lung donors up to age 60 years. Any kind of smoking history is acceptable unless there is chronic obstructive pulmonary disease or pulmonary fibrosis on the chest radiograph. Sputum must be free from fungus, but gram-negative rods are treated with appropriate antibiotics. The arterial oxygen tension on an inspired oxygen fraction of 0.40 should be greater than 100 mm Hg, and a small pulmonary infiltrate is not worrisome. This liberalization of the donor pool for lung and heart-lung transplantation has not adversely affected early outcome.

Memory improvement following cardiac transplantation

Seventeen patients with severe cardiomyopathy underwent neuropsychological evaluation prior to and at least 1 year after successful heart transplantation. Study candidates were screened, and individuals with a history of stroke, cardiac arrest, or medical and neurological conditions which might affect brain function were excluded. Pre-transplant testing revealed normal intelligence and normal attentional, language, and executive abilities but impaired recent memory. Following heart transplant, memory functioning improved significantly, reaching normal levels. Other cognitive abilities remained unchanged. Results suggest that cardiomyopathy is associated with mesial temporal dysfunction, possibly attributable to inadequate or reduced cerebral blood flow and related hypometabolism. This cerebral dysfunction is potentially reversible following successful transplantation, which restores cardiac output and cerebrovascular perfusion.

Lessons Learned From Experience With Over 100 Consecutive HeartMate II Left Ventricular Assist Devices

BACKGROUND Continuous-flow left ventricular assist devices (LVADs) such as the HeartMate II have become the therapy of choice in patients with end-stage heart failure. The aim of this study is to report the outcomes in patients receiving the HeartMate II LVAD at a single center and review the lessons learned from this experience. METHODS From June 2005 to June 2010, 130 consecutive patients received the HeartMate II LVAD. Of these, 102 were bridge-to-transplant (BTT), 17 destination therapy, and 11 exchanges for failed HeartMate XVE. This study focuses on the 102 BTT patients. The HeartMate II was approved by the US Food and Drug Administration (FDA) as BTT in April 2008 and 64 patients received this device as BTT since that date. We review our experience with the device as BTT and report on patient survival and adverse events as well as the impact of FDA approval on outcomes. RESULTS Overall, mean age was 52.6 ± 12.8 years; 26 (25.5%) were female. Disease etiology was ischemic in 58, nonischemic in 36, and other in 8. Overall, 30-day, 6-month, and 1-year survival for the BTT patients was 95.1%, 83.5%, and 78.8%, respectively. The 6-month survival in 38 patients in the clinical trial (pre-FDA) was 88.8% and was not statistically significant compared with the 76.2% 6-month survival in the 64 patients in the post-FDA approval period (p value = 0.1). Major adverse events among the 102 BTT patients included right ventricular failure in 5 (4.9%), LVAD driveline infections in 25 (24.5%), neurologic events in 10 (9.8%), and gastrointestinal bleeding in 18 (17.6%) patients. In addition, 1 patient (0.98%) had pump thrombus requiring device replacement. CONCLUSIONS Despite significant morbidity, use of the HeartMate II LVAD as BTT provides excellent hemodynamic support and is associated with excellent survival and low mortality. In addition, there needs to be improvement and focused strategies in the areas of gastrointestinal bleeding, driveline infections, and adverse neurologic events for these devices to be able to provide a real long-term alternative to heart transplantation.

Risk of Adverse Outcomes Associated With Blood Transfusion After Cardiac Surgery Depends on the Amount of Transfusion

BACKGROUND Blood product transfusion has been known for immunosuppressive effects, and over-transfusion is linked with adverse outcomes. In cardiac surgery, the risk of non-transfusion can be poor postoperative oxygen delivery and hemorrhage. We hypothesized that infectious complications, organ dysfunction, and mortality result after a given threshold of blood product transfusion is exceeded. METHODS Retrospectively, a prospectively maintained institutional database was analyzed from April 1, 2004 through December 31, 2006. All patients undergoing coronary artery bypass and/or valve operations were evaluated for bivariate and multivariate associations of blood-product transfusion with postoperative complications and mortality. Additionally, risk factors associated with transfusion were assessed. Receiver operator characteristic (ROC) curves analyses were employed to determine transfusion thresholds associated with complications. RESULTS During the study period, 741 patients met inclusion criteria. Fifty-four percent received postoperative blood-product transfusions. Previous cardiac intervention, renal dysfunction, stroke, and immunosuppression were some of the risks associated with transfusion (P < 0.05). Specific complications independently (P < 0.05) associated with total blood product transfusion identified from the multivariate analysis were infectious, neurologic, organ dysfunction, cardiac, and death. From ROC curve analyses, 5.5 units of total blood product transfusion was the inflection point for infectious complications (sensitivity 73%, specificity 64%) and organ dysfunction (sensitivity 73%, specificity 64%). For mortality, the inflection point was a transfusion of 7.5 units of total blood-products (sensitivity 73%, specificity 71%). CONCLUSION Bloodless cardiac surgery is associated with a decreased morbidity and mortality. Limiting transfusion is advisable. Transfusion of less than 5.5 units of total blood-products may not have deleterious effects on outcomes.

Adjunctive coronary endarterectomy: Improved safety in modern cardiac surgery

BACKGROUND Advances in cardiac surgery have led to an improved safety record for coronary endarterectomy. METHODS We retrospectively reviewed the cases of 64 patients who underwent adjunctive coronary endarterectomy between August 1988 and February 1992. There were 44 men, and the mean age was 65 years. Forty-one patients (64%) had sustained a previous infarction. Overall, endarterectomy was performed on 76 vessels, and the right coronary system was involved in 46 (61%). RESULTS The postoperative infarction rate was 5%. Incomplete occlusion ( < 90% stenosis) of the endarterectomized vessel significantly increased the risk of infarction (p < 0.05). There were two early deaths (3%). The mean follow-up was 46 months. Clinically, 91% of the survivors were angina free, and 80% had no symptoms of heart failure at the time of follow-up. Left ventricular function had improved in 36% of those restudied (5/14). A total of 17 recatheterizations were done at a mean interval of 19 months after operation. The endarterectomy graft patency rate was 80% (16/20) compared with 78% (28/36) for conventional grafts ( p = not significant). The actuarial survival rates were 89% and 71% at 1 year and 5 years, respectively. A history of previous infarction was significantly associated with higher long-term mortality (p < 0.02). CONCLUSIONS Overall, these results demonstrate that in modern cardiac surgery, coronary endarterectomy is safer than previously thought and can be used effectively to achieve complete revascularization in selected patients.

Postcardiac transplant survival in the current era in patients receiving continuous-flow left ventricular assist devices.

OBJECTIVES Continuous-flow left ventricular assist devices have become the standard of care for patients with heart failure requiring mechanical circulatory support as a bridge to transplant. However, data on long-term post-transplant survival for these patients are limited. We evaluated the effect of continuous-flow left ventricular assist devices on postcardiac transplant survival in the current era. METHODS All patients who received a continuous-flow left ventricular assist device as a bridge to transplant at a single center from June 2005 to September 2011 were evaluated. RESULTS Of the 167 patients who received a continuous-flow left ventricular assist device as a bridge to transplant, 77 (46%) underwent cardiac transplantation, 27 died before transplantation (16%), and 63 (38%) remain listed for transplantation and continued with left ventricular assist device support. The mean age of the transplanted patients was 54.5 ± 11.9 years, 57% had an ischemic etiology, and 20% were women. The overall mean duration of left ventricular assist device support before transplantation was 310 ± 227 days (range, 67-1230 days). The mean duration of left ventricular assist device support did not change in patients who had received a left ventricular assist device in the early period of the study (2005-2008, n = 62) compared with those who had received a left ventricular assist device later (2009-2011, n = 78, 373 vs 392 days, P = NS). In addition, no difference was seen in survival between those patients supported with a left ventricular assist device for fewer than 180 days or longer than 180 days before transplantation (P = NS). The actuarial survival after transplantation at 30 days and 1, 3, and 5 years by Kaplan-Meier analysis was 98.7%, 93.0%, 91.1%, and 88.0%, respectively. CONCLUSIONS The short- and long-term post-transplant survival for patients bridged with a continuous-flow left ventricular assist device in the current era has been excellent. Furthermore, the duration of left ventricular assist device support did not affect post-transplant survival. The hemodynamic benefits of ventricular unloading with continuous-flow left ventricular assist devices, in addition to their durability and reduced patient morbidity, have contributed to improved post-transplant survival.

Recommendations of the National Heart, Lung, and Blood Institute Working Group on Future Direction in Cardiac Surgery

New surgical procedures, imaging modalities, and medical devices have improved therapy for many patients and made treatment possible for others who have had few options in the past. In February 2004, the National Heart, Lung, and Blood Institutes (NHLBI) Advisory Council proposed that the institute evaluate the status and future directions in cardiac surgery. In response to this recommendation, the NHLBI convened a working group of cardiac surgeons on May 7 and 8, 2004, to assess the state of cardiac surgery research, identify critical gaps in current knowledge, determine areas of opportunity, and obtain specific recommendations for future research activities. The working group discussed surgical revascularization, novel surgical approaches, valvular research directions, biotechnology and cell-based therapy, heart failure, imaging modalities, and barriers to clinical research and presents its recommendations here.