Incidence, Risk Score Performance, and In-Hospital Outcomes of Postoperative Atrial Fibrillation After Cardiac Surgery.

BACKGROUND: Postoperative atrial fibrillation (POAF) frequently complicates cardiac surgery. Predicting POAF can guide interventions to prevent its onset. This study assessed the incidence, risk factors, and related adverse outcomes of POAF after cardiac surgery. METHODS: A cohort of 1,606 patients undergoing cardiac surgery at a tertiary referral center was analyzed. Postoperative AF was defined based on the Society of Thoracic Surgeons' criteria: AF/atrial flutter after operating room exit that either lasted longer than 1 hour or required medical or procedural intervention. Risk factors for POAF were evaluated, and the performance of established risk scores (POAF, HATCH, COM-AF, CHA2DS2-VASc, and Society of Thoracic Surgeons risk scores) in predicting POAF was assessed using discrimination (area under the receiver operator characteristics curve) analysis. The association of POAF with secondary outcomes, including length of hospital stay, ventilator time, and discharge to rehabilitation facilities, was evaluated using adjusted linear and logistic regression models. RESULTS: The incidence of POAF was 32.2% (n = 517). Patients who developed POAF were older, had traditional cardiovascular risk factors and higher Society of Thoracic Surgeons risk scores, and often underwent valve surgery. The POAF risk score demonstrated the highest area under the receiver operator characteristics curve (0.65), but risk scores generally underperformed. Postoperative AF was associated with extended hospital stays, longer ventilator use, and higher likelihood of discharge to rehabilitation facilities (odds ratio, 2.30; 95% CI, 1.73-3.08). CONCLUSION: This study observed a high incidence of POAF following cardiac surgery and its association with increased morbidity and resource utilization. Accurate POAF prediction remains elusive, emphasizing the need for better risk-prediction methods and tailored interventions to diminish the effect of POAF on patient outcomes.

Clinical Predictors and Outcomes After Left Ventricular Assist Device Implantation and Tracheostomy.

BACKGROUND: Postoperative respiratory failure is a major complication that affects up to 10% of patients who undergo cardiac surgery and has a high in-hospital mortality rate. Few studies have investigated whether patients who require tracheostomy for postoperative respiratory failure after continuous-flow left ventricular assist device (CF-LVAD) implantation have worse survival outcomes than patients who do not. OBJECTIVE: To identify risk factors for respiratory failure necessitating tracheostomy in CF-LVAD recipients and to compare survival outcomes between those who did and did not require tracheostomy. METHODS: Consecutive patients who underwent primary CF-LVAD placement at a single institution between August 1, 2002, and December 31, 2019, were retrospectively reviewed. Propensity score matching accounted for baseline differences between the tracheostomy and nontracheostomy groups. Multivariate logistic regression was used to identify tracheostomy risk factors and 90-day survival; Kaplan-Meier analysis was used to assess midterm survival. RESULTS: During the study period, 664 patients received a CF-LVAD; 106 (16.0%) underwent tracheostomy for respiratory failure. Propensity score matching produced 103 matched tracheostomy-nontracheostomy pairs. Patients who underwent tracheostomy were older (mean [SD] age, 57.9 [12.3] vs 54.6 [13.9] years; P = .02) and more likely to need preoperative mechanical circulatory support (61.3% vs 47.8%; P = .01) and preoperative intubation (27.4% vs 8.8%; P < .001); serum creatinine was higher in the tracheostomy group (mean [SD], 1.7 [1.0] vs 1.4 [0.6] mg/dL; P < .001), correlating with tracheostomy need (odds ratio, 1.76; 95% CI, 1.21-2.56; P = .003). Both before and after propensity matching, 30-day, 60-day, 90-day, and 1-year survival were worse in patients who underwent tracheostomy. Median follow-up was 0.8 years (range, 0.0-11.2 years). Three-year Kaplan-Meier survival was significantly worse for the tracheostomy group before (22.0% vs 61.0%; P < .001) and after (22.4% vs 48.3%; P < .001) matching. CONCLUSION: Given the substantially increased probability of death in patients who develop respiratory failure and need tracheostomy, those at high risk for respiratory failure should be carefully considered for CF-LVAD implantation. Comprehensive management to decrease respiratory failure before and after surgery is critical.

Preoperative hyponatremia and survival after left ventricular assist device implantation.

BACKGROUND: Hyponatremia is associated with adverse outcomes in heart failure and after cardiac surgery. We hypothesized that hyponatremia is associated with poorer short-term and longer term survival in patients after continuous-flow left ventricular assist device (CF-LVAD) placement. METHODS: We reviewed a single-center database of patients who received a CF-LVAD during 2012-2017. Sodium (Na) values obtained within 14 days before CF-LVAD insertion were averaged; patients (n = 332) were divided into hyponatremia (mean Na <135 mEq/L; n = 160; 48.2%) and normonatremia groups (mean Na 135-145 mEq/L; n = 172; 51.8%). Patients requiring preoperative dialysis or pump exchange were excluded. We compared outcomes between preoperative hyponatremia and normonatremia groups. RESULTS: The two groups' baseline characteristics were similar, although hyponatremia patients more often had preoperative mechanical circulatory support (44.4% vs. 31.4%, p = 0.002). Although hyponatremic and normonatremic patients did not differ in 30-day mortality (7.5% vs. 6.5%, p = 0.7), preoperative hyponatremia was associated with greater 5-year mortality (61% vs. 44%, p = 0.03). On binary logistic regression analysis, the strongest independent predictors of late mortality were hyponatremia (odds ratio [OR] 1.88, 95% CI [1.07-3.31], p = 0.02), older age (OR 1.03, 95% CI [1.01-1.05], p = 0.01), and elevated mean right atrial pressure/pulmonary capillary wedge pressure ratio (OR 4.69, 95% CI [1.76-12.47], p = 0.002). CONCLUSIONS: Hyponatremia was not associated with greater early mortality but was associated with poorer late survival. The optimal timing of LVAD implantation in relation to hyponatremia, and whether correcting hyponatremia perioperatively improves long-term survival, should be investigated.

Increased blood transfusion and its impact in patients having tracheostomy while on extracorporeal membrane oxygenation.

INTRODUCTION: Tracheostomy has been utilized in combination with venovenous extracorporeal membrane oxygenation (VV-ECMO) to enable early spontaneous breathing and minimize sedation requirements. Tracheostomy has been previously reported to be safe in patients supported on VV-ECMO; however, the impact of tracheostomy on blood loss in VV-ECMO patients is unknown. METHODS: We analyzed VV-ECMO patients with and without tracheostomy over a 5-year period. In order to avoid other potential sources of blood loss not related to tracheostomy or ECMO-related blood loss, patients who underwent a recent surgery prior to ECMO or during ECMO (other than tracheostomy) were excluded. RESULTS: Sixty-three patients meeting the inclusion criteria were identified (tracheostomy n=30, non-tracheostomy n=33). Tracheostomy patients were found to require more daily transfusions of red blood cells (RBC) (0.47 [0.20-1.0] vs. 0.23 [0.06-0.40] units/day, p=0.02) and total blood products (0.60 [0.32-1.0] vs. 0.31 [0.10-0.50] units/day, p=0.01). CONCLUSIONS: These results suggest that tracheostomy while on VV-ECMO predisposes patients to increased transfusion burden. Based on previous research, this increased transfusion burden could potentially be linked to increased complications and mortality.

Impact of donor lung pathogenic bacteria on patient outcomes in the immediate post-transplant period.

BACKGROUND: Patient outcomes post-lung transplant remain inferior to other types of solid organ transplantation. We investigated whether the presence of potentially pathogenic bacteria (PPB) in donor lung bronchial cultures was associated with adverse outcomes postoperatively. METHODS: All patients who underwent lung transplantation between August 2015 and April 2017 at the University of Kentucky Medical Center were retrospectively reviewed. Retransplants, patients with bronchiectasis (including cystic fibrosis), and individuals who received organs from donation after cardiac death (DCD) donors were excluded. The remaining subjects were separated into two groups: individuals whose donor bronchial cultures grew PPB, and those whose cultures either returned negative for PPB or were sterile. 30-day mortality rates as well as the incidence of grade 3 primary graft dysfunction (PGD) and acute kidney injury (AKI) at both 24 and 72 hours post-transplant were calculated. The duration of mechanical ventilation postoperatively was also recorded. RESULTS: Thirty two subjects comprised the study population. 20 patients (63%) had growth of PPB on donor cultures, while 12 (37%) did not. Patients with PPB had a significantly greater number of days on the ventilator postoperatively compared to those with no PPB (mean = 11.3 and median = 5.0 vs mean = 5.8 and median = 3.0, respectively, P = 0.0232). Subsequent regression analysis revealed this association to not be influenced by recipient lung allocation score (LAS), donor age, donor smoking history, recipient mean pulmonary artery pressure (mPAP) value, and/or use of cardiopulmonary bypass at the time of transplantation. Neither 30-day survival nor incidence of Grade 3 PGD and AKI at 24 or 72 hours post-transplant differed between the two groups (P > 0.05). CONCLUSION: The recovery of PPB in donor lung cultures was associated with a longer duration of mechanical ventilation postoperatively in lung transplant recipients.

Clinical and morphologic features of acute, subacute and chronic cor pulmonale (pulmonary heart disease).

Described are certain clinical and morphologic features of one patient with acute, another with subacute, and one with chronic cor pulmonale. All 3 had evidence of severe pulmonary hypertension. The patient with acute cor pulmonale 4 days after coronary bypass for unstable angina pectoris suddenly developed severe breathlessness with cyanosis and had fatal cardiac arrest and necropsy disclosed massive pulmonary embolism. The patient with subacute cor pulmonale had severe right-sided heart failure for 5 weeks and necropsy disclosed microscopic-sized neoplastic pulmonary emboli from a gastric carcinoma without parenchymal pulmonary metastases. The patient with chronic cor pulmonale had evidence of right-sided heart failure for years, the result of primary or idiopathic pulmonary hypertension almost certainly present from birth because the pattern of elastic fibers in the pulmonary trunk was that seen in newborns where the pressure in the pulmonary trunk and ascending aorta are similar. The patient with chronic cor pulmonale had plexiform pulmonary lesions indicative of irreversible pulmonary hypertension. Neither the acute nor the subacute patient had chronic pulmonary vascular changes. All 3 patients had dilated right ventricular cavities and non-dilated left ventricular cavities and only the patient with chronic cor pulmonale had right ventricular hypertrophy.

Expanding the donor pool: donation after cardiac death.

Lung transplantation (LTx) is the definitive treatment of patients with end-stage lung disease. Availability of donor lungs remains the primary limitation and leads to substantial wait-list mortality. Efforts to expand the donor pool have included a resurgence of interest in the use of donation after cardiac death (DCD) lungs. Unique in its physiology, lung viability seems more tolerant to the variable durations of ischemia that occur in DCD donors. Initial experience with DCD LTx is promising and, in combination with ex vivo lung perfusion systems, seems a valuable opportunity to expand the lung donor pool.

Too high for transplantation? Single-center analysis of the lung allocation score.

BACKGROUND: Recent studies using United Network for Organ Sharing data suggest that lung transplantation in patients with high lung allocation scores (LAS) may lead to organ and resource wastage. Therefore, to determine whether a LAS cutoff value should be considered, we evaluated the relation of LAS to waitlist and posttransplant mortality in our center to determine if it could identify patients for whom listing for transplantation may be futile. METHODS: From May 1, 2005 to July 1, 2010, 537 adults were listed and 426 underwent primary lung transplantation at our institution. Endpoints were mortality before and after lung transplantation. The relationships of LAS at listing to waitlist mortality and of pretransplant LAS to posttransplant mortality were both analyzed by multiphase hazard function methodology. RESULTS: Higher LAS was strongly associated with waitlist mortality (p<0.0001), with the highest quartile (LAS ranging from 47 to 95) experiencing 75% mortality within a year of listing. Although early (p=0.05), but not late (p=0.4), posttransplant survival was associated with higher LAS at transplantation, once other clinical characteristics predictive of early mortality were accounted for, neither waitlist nor pretransplant LAS was independently related to posttransplant mortality (p=0.12). CONCLUSIONS: Higher LAS strongly predicts higher mortality on the lung transplantation waitlist, underscoring the value of LAS in prioritizing patients with the highest scores for transplantation. Early posttransplant mortality is modestly higher with higher pretransplant LAS, but the data of our center do not suggest a value above which transplantation should be denied as futile. This suggests that donor organs and resources are not being wasted.

Outcomes of axillary artery side graft cannulation for extracorporeal membrane oxygenation.

OBJECTIVE: To determine the safety, efficacy, and frequency of side graft axillary artery cannulation for extracorporeal membrane oxygenation support and compare it with other cannulation techniques. METHODS: From January 2001 to October 2011, 308 adult patients were supported with extracorporeal membrane oxygenation at a single center. In 81 patients (26.3%), the extracorporeal membrane oxygenation circuit was composed of an arterial inflow by a side graft sewn to the axillary artery. Of the 308 patients, 166 (53.9%) underwent femoral arterial cannulation and 61 (19.8%) underwent ascending aortic cannulation The pertinent variables and postprocedural events were retrospectively analyzed in this cohort of patients. RESULTS: The most common complication in the axillary artery group was hyperperfusion syndrome of the ipsilateral upper extremity (n = 20, 24.7%), followed by bleeding from the arterial outflow graft (n = 14, 17.3%). Lower extremity ischemia and fasciotomy were more frequent after femoral arterial cannulation (n = 27, 16%, and n = 18, 10.8%, respectively). The predictors for a poor in-hospital outcome for the entire group of patients were age and postoperative cerebral vascular accident. The cannulation method was not a predictor of in-hospital outcomes. CONCLUSIONS: Extracorporeal membrane oxygenation support with side graft axillary artery technique was more frequently associated with hyperperfusion syndrome than other cannulation sites. Lower extremity ischemia and compartment syndrome was more common after femoral arterial cannulation.

Combined heart and liver transplantation: the Cleveland Clinic experience.

BACKGROUND: Combined heart-liver transplantation (CHLT) has been utilized as a life-saving procedure in those with end-stage cardiac and hepatic pathology. Techniques and outcomes of this procedure are varied. We sought to review the Cleveland Clinic experience with CHLT. METHODS: This study is a retrospective chart review of patients who received simultaneous heart and liver transplantation between January 2006 and December 2012. RESULTS: Five patients received CHLT. The mean age was 49 (± 20) years. All cardiac pathology was nonischemic cardiomyopathy, with a mean ejection fraction of 0.36 (± 0.13). Three of the 5 were on preoperative inotropic support, 1 of which required placement of a total artificial heart for support pretransplant. Liver pathology was amyloid in 1 patient and hepatitis C in the remaining 4. Mean Model for End-Stage Liver Disease score was 17 (± 5), and mean Childs-Pugh score was 8 (± 1). Survival, now at a mean of 38 (± 20) months remains 100%, with no cardiac or hepatic graft dysfunction or episodes of rejection. One hospital readmission was required for gastroenteritis at 15 months posttransplant. CONCLUSIONS: These results suggest that excellent outcomes can be achieved in this extremely sick cohort of patients, and add to the growing literature of perioperative management of CHLT recipients.

Growing experience with extracorporeal membrane oxygenation as a bridge to lung transplantation.

Extracorporeal membrane oxygenation (ECMO) is rarely used as a bridge to lung transplantation (BTT) because of its associated morbidity and mortality. However, recent advancements in perfusion technology and critical care have revived interest in this application of ECMO. We retrospectively reviewed our utilization of ECMO as BTT and evaluated our early and midterm results. Nineteen patients were placed on ECMO with the intent to transplant of which 14 (74%) were successfully transplanted. Early and midterm survival of transplanted patients was 75% (1 year) and 63% (3 years), respectively, with the most favorable results observed in interstitial lung disease patients supported in the venovenous configuration. Extracorporeal membrane oxygenation-bridged transplant survival rates were equivalent to nonbridged recipients, but early morbidity and mortality are high and the failure to bridge to transplant is significant. Overall, successfully bridged patients can derive a tangible benefit, albeit with considerable consumption of resources.

Subclavian insertion of the bicaval dual lumen cannula for venovenous extracorporeal membrane oxygenation.

Extracorporeal membrane oxygenation (ECMO) has demonstrated utility in the management of adult respiratory failure refractory to mechanical ventilation. The recent introduction of a bicaval dual-lumen ECMO cannula has improved the efficiency of venovenous ECMO and has enabled the concept of full extracorporeal respiratory support in place of mechanical ventilation. Standard placement of this cannula through the right internal jugular vein is particularly troublesome in individuals of short stature, because of excess cannula length. We describe a method for cannula placement through the left subclavian vein that is well suited for smaller patients and convenient for patient mobility.

Changes in left ventricular morphology and function after mitral valve surgery.

Degenerative mitral valve disease is the leading cause of mitral regurgitation in North America. Surgical intervention has hinged on the symptoms and ventricular changes that develop as compensatory ventricular remodeling occurs. In the present study, we sought to characterize the temporal response of left ventricular (LV) morphology and function to mitral valve surgery for degenerative disease and to identify the preoperative factors that influence reverse remodeling. From 1986 to 2007, 2,778 patients with isolated degenerative mitral valve disease underwent valve repair (n = 2,607 [94%]) or replacement (n = 171 [6%]) and had ≥1 postoperative transthoracic echocardiogram; 5,336 transthoracic echocardiograms were available for analysis. Multivariate longitudinal repeated-measures analysis was performed to identify the factors associated with reverse remodeling. The LV dimensions decreased in the first year after surgery (end-diastolic from 5.7 ± 0.80 to 4.9 ± 1.4 cm; end-systolic from 3.4 ± 0.71 to 3.1 ± 1.4 cm). The LV mass index decreased from 139 ± 44 to 112 ± 73 g/m(2). The reduction in LV hypertrophy was less pronounced in patients with greater preoperative left heart enlargement (p <0.0001) and a greater preoperative LV mass (p <0.0001). The postoperative LV ejection fraction initially decreased from 58 ± 7.0% to 53 ± 20%, increased slightly during the first postoperative year, and was negatively influenced by preoperative heart failure symptoms (p <0.0001) and a lower preoperative LV ejection fraction (p <0.0001). The risk-adjusted response of LV morphology and function to valve repair and replacement was similar (p >0.2). In conclusion, a positive response toward normalization of LV morphology and function after mitral valve surgery is greatest in the first year. The best response occurs when surgery is performed before left heart dilation, LV hypertrophy, or LV dysfunction develop.

Total arch replacement after a failed repair for Takayasu's ascending aortitis.

The constellation of Takayasu's disease most commonly includes aortitis with resultant coarctations and aneurysm formation. Surgical repair of these lesions can be compromised by the chronic inflammation of Takayasu's arteritis. We present a case of a 22-year-old female with Takayasu's disease who had undergone an ascending and aortic hemiarch replacement then subsequently developed anastomotic dehiscence and re-expansion of the previous aneurysmal sac. Complete aneurysm resection and replacement of the ascending aorta and aortic arch was performed on repeated surgery.

Perforated gastric corpus in a strangulated paraesophageal hernia: a case report.

INTRODUCTION: Patients with paraesophageal hernias often present secondary to chronic symptomatology. Infrequently, acute intestinal ischemia and perforation can occur as a consequence of paraesophageal hernias with potentially dire consequences. CASE PRESENTATION: An 86-year-old obtunded male presented to the emergency department with hypotension and severe back and abdominal pain. An emergency abdominal CT scan was ordered with a presumptive diagnosis of ruptured abdominal aortic aneurysm. CT topograms revealed extensive free intra-abdominal air and herniated abdominal viscera into the right hemithorax. Prior to completion of the CT study, the patient sustained a cardiopulmonary arrest. Surgery was consulted, but the patient was unable to be revived. Post-mortem examination revealed gross contamination within the abdomen and a giant, incarcerated, hiatal hernia with organoaxial volvulus and ischemic perforation. CONCLUSION: Current recommendations call for prompt repair of giant hiatal hernias before they become symptomatic due to the increased risk of strangulation. Torsion of the stomach in large hiatal hernias frequently leads to a fatal complication such as this warranting elective repair as soon as possible.