Faculty Bibliography

OBJECTIVE:Advances in transcatheter aortic valve replacement have led to the consideration of tissue aortic valve replacement in younger patients. Part of this enthusiasm is the presumption that younger patients would have more flexibility in future treatment options, such as a primary surgical aortic valve replacement followed later by transcatheter aortic valve replacement(s) (valve-in-valve), vice versa, or other permutations. We created a microsimulation model using published longevity of tissue valves to predict the outcomes of patients after primary tissue surgical aortic valve replacement. METHODS:The model calculated survival by incorporating annual mortality (Social Security Administration) and mortality from re-replacements (Society of Thoracic Surgeons) in patients with surgical aortic valve replacement. Freedom from reoperation for structural valve degeneration incorporated best published data to determine the annual risk of re-replacement for structural valve degeneration based on implant duration and stratified by patient age. A constant rate of re-replacement for nonstructural valve degeneration indications was also incorporated. Each simulation was performed for 50,000 individuals. Kaplan-Meier curves were generated to represent survival. All simulations were run within the MATLAB environment (The MathWorks, Inc, Natick, Mass). RESULTS:Earlier decades of life at primary surgical aortic valve replacement were associated with higher incidences of re-replacements and especially multiple re-replacements. For those patients receiving a primary tissue surgical aortic valve replacement at age 50 years, 57.2% will require a second valve, 18.0% will require a third valve, and 1.6% will require a fourth valve with average operative mortalities of 2.9%, 4.8%, and 7.3%, respectively. A 50-year-old patient at primary surgical aortic valve replacement has a 13.1% chance of re-replacement before turning 60 years of age. CONCLUSIONS:Microsimulation incorporates changing hazards to estimate the risk of aortic valve re-replacement in patients undergoing tissue surgical aortic valve replacement and may be a starting point for patient education and healthcare economic planning.

Objective: Pulmonary embolism response teams (PERTs)have become increasingly popular at institutions around the country, although only anecdotal evidence is available to support their efficacy. PERTs are mechanisms for rapid involvement of a multidisciplinary team in the management of a time-sensitive condition with many treatment options spanning multiple specialties. We aimed to evaluate time to management of pulmonary embolisms and outcomes since 2016 under our institution's PERT. Method(s): We retrospectively reviewed 151 patients with PERT activations since inception, collecting data on demographics, time to treatment, treatment modality, and in-hospital outcomes. Result(s): The average age was 62.4 years (range, 30-95 years), and 54% of patients were male; 39.4% of patients had normal echocardiographic recordings, with 27% showing right ventricular (RV)hypokinesis, 9.1% showing elevated pulmonary artery pressures, and 6.1% showing RV enlargement. Anticoagulation alone was received by 91.4% of patients; 4.5% had catheter-directed therapy (CDL), and 3.0% had systemic administration of tissue plasminogen activator (tPA). The average time to invasive intervention was 665 minutes (95% confidence interval [CI], 249-1080 minutes)for CDL and 22 minutes (95% CI, 0-456 minutes)for systemic tPA. Average time to anticoagulation was 3 minutes (95% CI, 154-160 minutes). For patients with echocardiographic findings suggestive of RV strain, 21.4% (95% CI, 0.04-0.51)had tPA or an invasive intervention. Of patients with echocardiographic findings consistent with RV strain who underwent conservative management, 80% were discharged home after an average length of stay of 6.0 days (95% CI, 4.5-7.5). Twenty (14.1%; 95% CI, 5.5-22.5)patients receiving anticoagulation alone had bleeding events, whereas none of the patients undergoing CDL or tPA had bleeding. Sixteen (11.2%; 95% CI, 5.7-16.3)patients who had anticoagulation died in the hospital or were discharged to hospice, and none of the patients receiving CDL or tPA died or were discharged to hospice. The odds of in-hospital death were lower for patients receiving anticoagulation than for those without (odds ratio, 0.29), suggesting appropriate identification of high-risk patients. Average hospital stay was 6.5 days (95% CI, 4.9-8.5)for patients who received anticoagulation, 5.3 days for CDL (95% CI, 0-11.2), and 8 days for tPA (95% CI, 2.6-13.4). Conclusion(s): We found that a dedicated PERT team leads to efficient delivery of care and excellent outcomes. The majority of pulmonary embolisms can be managed with anticoagulation alone. CDT and systemic tPA are safe adjunctive treatments for select patients.

Purpose: The opioid epidemic has expanded the cardiac donor pool, but the concern for primary graft dysfunction (PGD) remains a barrier to wider utilization of these hearts. We analyzed donor characteristics in transplanted and discarded cardiac allografts from overdosed donors (ODD) to determine if viable ODD hearts are being unnecessarily discarded due to inappropriate bias. Method(s): Data on adult cardiac transplantation from 2010-2017 were provided by the SRTR. Eight donor characteristics associated with PGD were analyzed: age, gender, hypertension, high creatinine, cocaine abuse, inotropic support, LVEF, and cardiac arrest. Donor characteristics of transplanted and discarded hearts were compared between ODD and non-ODD. Result(s): ODD comprised 11% (1710/15904) of transplanted hearts and 7% (2600/32678) of discarded hearts. Among transplanted hearts, ODD more frequently were younger than 50 (98% vs 90%), did not have hypertension (86% vs 83%), and did not require inotropic support (62% vs 55%) compared to non-ODD; ODD less frequently were male (63% vs 70%), had no history of cocaine abuse (57% vs 84%), or had creatinine <=1.5 (62% vs 81%). Among discarded hearts, ODD more frequently were younger than 50 (87% vs 46%), had no history of hypertension (78% vs 49%), and did not require inotropic support (51% vs 41%); ODD less often had no history of cocaine abuse (50% vs 86%) or creatinine <=1.5 (61% vs 69%) (Table). Donors known to have at least 6 of 8 favorable qualities comprised 36% (942/2600) of discarded ODD hearts, compared to 28% (9152/32678) of discarded non-ODD hearts (p<0.001). The most common reasons given for discard of ODD hearts with favorable qualities were poor organ function (18%), refusal by all programs (16%), and lack of recipient (11%). Conclusion(s): ODD hearts with favorable qualities are being discarded at disproportionally higher rates than non-ODD hearts. Further studies and better documentation are needed to understand current discard practices and if further expansion into this donor pool is appropriate.

Purpose: Controversy remains over the mortality benefit of single (SLT) versus double lung transplantation (DLT) in idiopathic pulmonary fibrosis (IPF). Independent of this controversy, hesitancy to perform SLT in this population exists on the basis of unclear one year functional status. We compared functional status at one year between IPF patients listed for both who ultimately received SLT or DLT. Method(s): All consecutive adult lung transplants for IPF provided by the Scientific Registry of Transplant Recipients were retrospectively reviewed (2007-2017). Isolated lobar transplants (n=4), patients listed only for SLT (n=1834) or DLT (n=2372), and patients with missing functional status data (n=715) were excluded. Group stratification was based on the ultimate procedure (SLT or DLT). Group propensity matching was performed based on 25 recipient/donor characteristics. We compared 'good functional status' defined as >70%, at one year. Result(s): During the study period, 45% (660/1464) and 55% (804/1464) of patients listed for both procedures ultimately received SLT and DLT, respectively. After propensity matching, 341 matched patients remained in each group. Donor and recipient characteristics were similar (Table). There was no statistically significant difference in 'good functional status' at one year between SLT (77%, 264/341) and DLT (81%, 275/341) (p=0.301). The same trend is present for patients younger than 50 who receive SLT (82%, 23/28) versus DLT (94%, 34/36) (p=0.225), and patients between 50 and 60 who receive SLT (78%, 86/110) versus DLT (84%, 97/115) (p=0.305). The opposite trend is noted in patients older than 70 who receive SLT (72%, 13/18) versus DLT (61%, 11/18) (p=0.725). Conclusion(s): In this cohort of lung transplant recipients listed for both SLT and DLT, functional status was statistically similar between groups, even in younger recipients. This data suggests that SLT should not be precluded in IPF patients on the basis of expected functional status at one year.