The Thoracic Surgery Medical Student Association: Understanding the needs of medical students pursuing cardiothoracic surgery in the United States

OBJECTIVE

Founded in 2020, the Thoracic Surgery Medical Student Association is the first national organization dedicated to supporting medical students interested in pursuing cardiothoracic surgery. Our inaugural survey aimed to describe their basic characteristics and needs.

METHODS

An Institutional Review Board-approved, nonincentivized, anonymous electronic survey was distributed to any medical students enrolled in Liaison Committee on Medical Education-accredited medical schools through social media such as Twitter, national organizations (Association of Women Surgeons, Thoracic Surgery Resident Association), and medical school cardiothoracic surgery interest groups. Their basic characteristics, attitudes, and preferences regarding cardiothoracic surgery were recorded.

RESULTS

Of the 167 students from 117 unique schools who completed the survey, 53% identified as White and 57% identified as female. Stages of training were well distributed: 16% first-year medical students, 33% second-year medical students, 16% third-year medical students, 21% fourth-year medical students, and 14% dual degree/research students. Most participants (57%) did not have (32%) or were not aware of having (25%) a thoracic surgery training program at their home institution. The majority (72%) of students reported not having a cardiothoracic surgery interest group at their home institution. The most desired areas of cardiothoracic were networking (31%) and mentorship (28%).

CONCLUSIONS

There is a significant need to directly engage medical students who are interested in cardiothoracic surgery considering limited exposure at home institutions through a lack of cardiothoracic surgery interest groups and cardiothoracic residency programs. The Thoracic Surgery Medical Student Association is poised to address these areas with directed networking by connecting cardiothoracic surgery faculty and residents from other institutions with medical students interested in pursuing cardiothoracic surgery.

Time since primary transplant and poor functional status predict survival after redo lung transplant

BACKGROUND

In previous studies, lower functional status measured by Karnofsky Performance Status (KPS) correlated with worse survival after redo lung transplant. We hypothesize that combining reduced functional status and time from primary lung transplant will correlate with the etiology of lung allograft failure after primary lung transplant and more accurately predict survival after redo lung transplant.

METHODS

This retrospective study was approved by University of Minnesota Institutional Review Board. From the Scientific Registry of Transplant Recipients (SRTR) database, 739 patients underwent redo lung transplant (01/01/2005-8/30/2019). Pre-lung transplant characteristics, KPS, time between primary and redo lung transplant, outcomes, overall survival were evaluated. Paired comparisons were used to compare pre-transplant variables. A Cox regression model was fit to examine re-transplant survival. Due to non-proportional hazards, time between transplants was split into <1-year vs. 1+ years and analyzed with time-dependent coefficients, with follow-up time considered in three segments (0-6, 6-24, 24+ months).

RESULTS

After KPS grouping (10-40%, 50-70%, 80-100%), KPS 10-40% were less likely to be discharged after primary transplant and more likely required mechanical ventilation or extracorporeal membrane oxygenation (ECMO) bridging (P<0.001). Redo lung transplant survival was worse in the KPS 10-40% group who more likely underwent lung transplant <1 year after primary lung transplant. Mortality was significantly higher for patients who underwent redo lung transplant within one year of primary transplant when KPS was 10-40% (P<0.001). These patients were more likely to require redo lung transplant due to primary graft failure or acute cellular rejection.

CONCLUSIONS

Functional status and time from primary lung transplant are strong predictors of outcome after redo lung transplant. We categorized redo lung transplant recipients in two distinct groups. One group has early allograft failure and poor functional status with a very poor prognosis after redo lung transplant. The other group has chronic allograft failure and overall better functional status with relatively better survival after redo lung transplant. Salvage redo lung transplant for primary allograft failure or acute rejection is associated with low one year survival.

Exercise-induced CITED4 expression is necessary for regional remodeling of cardiac microstructural tissue helicity

Both exercise-induced molecular mechanisms and physiological cardiac remodeling have been previously studied on a whole heart level. However, the regional microstructural tissue effects of these molecular mechanisms in the heart have yet to be spatially linked and further elucidated. We show in exercised mice that the expression of CITED4, a transcriptional co-regulator necessary for cardioprotection, is regionally heterogenous in the heart with preferential significant increases in the lateral wall compared with sedentary mice. Concordantly in this same region, the heart’s local microstructural tissue helicity is also selectively increased in exercised mice. Quantification of CITED4 expression and microstructural tissue helicity reveals a significant correlation across both sedentary and exercise mouse cohorts. Furthermore, genetic deletion of CITED4 in the heart prohibits regional exercise-induced microstructural helicity remodeling. Taken together, CITED4 expression is necessary for exercise-induced regional remodeling of the heart’s microstructural helicity revealing how a key molecular regulator of cardiac remodeling manifests into downstream local tissue-level changes.

Expression of transcription factor CITED4 is necessary for exercise-induced regional remodeling of the heart’s microstructural helicity, revealing how a key molecular regulator of cardiac remodeling mediates local tissue-level changes.

Coproduction in medical education during the COVID-19 pandemic: critical components of successful curricular reform

The current coronavirus disease 2019 pandemic has greatly affected medical education in unanticipated ways. By introducing the concept of educational coproduction at our institution, we have maintained a flexible and productive curricular environment for all students. The notion of coproduction acknowledges that education is a service that requires recognition of the expertise that both the teacher and the learner bring to the table, in the context of their community and society writ large. Using the coproduction framework allowed for increased communication and improved partnerships among students, educators, clinicians and our community as well as adaptations to a rapidly changing educational environment. Embracing the idea of coproduction is a valuable concept for institutions to consider during this time and in the future post-pandemic period.

Plasma Proteomics of COVID-19 Associated Cardiovascular Complications: Implications for Pathophysiology and Therapeutics

Cardiovascular complications are common in COVID-19 and strongly associated with disease severity and mortality. However, the mechanisms driving cardiac injury and failure in COVID-19 are largely unknown. We performed plasma proteomics on 80 COVID-19 patients and controls, grouped according to disease severity and cardiac involvement. Findings were validated in 305 independent COVID-19 patients and investigated in an animal model. Here we show that senescence-associated secretory proteins, markers of biological aging, strongly associate with disease severity and cardiac involvement even in age-matched cohorts. FSTL3, an indicator of Activin/TGFβ signaling, was the most significantly upregulated protein associated with the heart failure biomarker, NTproBNP (β = 0.4;p adj =4.6x10 - 7 ), while ADAMTS13, a vWF-cleaving protease whose loss-of-function causes microvascular thrombosis, was the most downregulated protein associated with myocardial injury (β=-0.4;p adj =8x10 - 7 ). Mendelian randomization supported a causal role for ADAMTS13 in myocardial injury. These data provide important new insights into the pathophysiology of COVID-19 cardiovascular complications with therapeutic implications.

Surgical Aortic Valve Replacement Outcomes in Non-TAVR Centers - Implications to Tier-Based Systems of Care

BACKGROUND

With wide expansion of Transcatheter aortic valve replacement (TAVR) and dissemination of multidisciplinary-based approaches to care, societies are discussing the implementation of a Tier-system to valve centers. This study explores the impact of Tier-based systems of care on Surgical AVR (SAVR) outcomes at institutions that perform SAVR only.

METHODS

Medicare beneficiaries undergoing SAVR procedures from 2012 - 2015 were included. SAVR Hospitals were stratified into either Tier A, valve centers with a TAVR program, and Tier B, valve centers without a TAVR program. Adjusted survival, assessed by multivariable Cox regression, controlled for program type and patient risk-profile. Time-dependent analysis accounted for hospitals that initiated a TAVR program during the study period.

RESULTS

Overall, there were 562 Tier A and 485 Tier B SAVR hospitals. Tier A hospitals had significantly higher comorbidity burden compared to Tier B hospitals (all P<0.05) but had significantly lower rates of 30-day mortality (3.2% vs 4.1%) and 1-year mortality (8.1% vs 9.4%; both P<0.05). After risk stratification, Tier B hospitals had significantly worse 30-day mortality compared to Tier A hospitals for all patient risk-profiles, except for the low-risk patients (P<0.01). These findings persisted in the time-dependent analysis. Adjusted mid-term survival was higher in Tier A versus Tier B hospitals.

CONCLUSIONS

Low-risk patients can safely undergo SAVR in both Tier levels without compromising outcomes. Establishment of quality of care measures, especially in the SAVR-only hospitals, remains paramount and should be closely integrated when designing Tier-based systems for AVR care.

Adult cardiac surgical cost variation around the world: Protocol for a systematic review

INTRODUCTION

Globally, over one million cardiac operations occur each year, whereas cardiac surgery is expensive and largely inaccessible without insurance or philanthropic support. Substantial cost variation has been reported within cardiac surgery in the United States and among non-cardiac surgical procedures globally, but little is known on the global procedural cost variation for common adult cardiac surgical procedures.

OBJECTIVES AND SIGNIFICANCE

This review seeks to assess variation in procedural costs of coronary artery bypass grafting (CABG), mitral valve repair, mitral valve replacement, aortic valve repair, aortic valve replacement, and combined CABG-mitral or CABG-aortic valve procedures between and within countries. Results may give insights in the scope and drivers of cost variation around the world, posing cost reduction lessons. Results may further inform the potential of economies of scale in reducing procedural costs, benefiting patients, hospitals, governments, and insurers.

METHODS AND ANALYSIS

A systematic review will be performed using the EconLit, Embase, PubMed/MEDLINE, Web of Science, and WHO Global Index Medicus databases to identify articles published between January 1, 2000 and June 1, 2020. Studies describing procedural costs for CABG, mitral valve repair, mitral valve replacement, aortic valve repair, aortic valve replacement, and combined CABG-mitral or CABG-aortic valve procedures will be identified. Articles describing other types of cardiac surgery, concomitant aortic surgery, only describing costs related to non-surgical care, or with incomplete cost data will be excluded from the analysis. No exclusion will be based solely on article type or language. Identified costs will be converted to 2019 USD to account for local currency unit inflation and exchange fluctuations.

ETHICS AND DISSEMINATION

This study protocol has been prospectively registered on the International Platform of Registered Systematic Review and Meta-analysis Protocols. This review requires no institutional review board approval. Results of this study will be summarized and disseminated in a peer-review journal.

Abstract 495: A Reappraisal of Body Mass Index and Aerobic Fitness in Young Athletic Women

Background: Lower body mass is thought to enhance athletic performance. We explored the relationship between BMI and aerobic fitness in athletic younger and older men and women.

Methods: We examined 2224 patients (805 women, 1419 men) ages 17 through 91, referred to the Cardiovascular Performance Program at Massachusetts General Hospital between 2011 and 2019. Cardiorespiratory fitness (CRF; Peak V0 2 ) was assessed and expressed as %- predicted peak V0 2 , using the equation of Jones to adjust for age, height, and weight. Associations were evaluated using linear regression.

Results: Mean peak VO 2 was 34.3±14.1 mL/kg/min, and median %-predicted VO 2 was 105%. We observed an inverse association between BMI and CRF in adults over 30 years old ( B = -0.043, p = 3.3x10 -33 for men, B = -0.051, p = 1.6 x 10 -13 for women) (Fig 1a) and men under 30 ( B = -0.025, p = 0.005) (Fig 1b). No linear association was found in younger women ages 17 - 29 ( B = -0.0078, p = 0.38) (Fig 1b). In contrast, a quadratic model disclosed a direct relationship at lower BMI and an inverse relationship at higher BMI (Fig 1c). An examination of high fitness young adults (defined as having %-predicted VO 2 ≥ 120%) demonstrates that fit women have mean BMI’s of 23.15 ± 2.69 (Fig 1d).

Conclusion: These data highlight that BMI and fitness in younger aerobically fit women do not follow a simple linear relationship but one that is parabolic in nature. High fitness in young women occurs with highest density in the upper strata of the WHO and NIH-defined range of healthy BMI. These data support a deemphasis of weight loss generally and BMI specifically to enhance aerobic performance in athletic young women.

Sex-based differences in mitral valve Re-operation after mitral valve repair: Truth or myth?

BACKGROUND

Outcomes after mitral valve (MV) repair are known to be worse in women. Less is known about sex-based differences in MV repair durability.

METHODS

All adult patients undergoing MV repair from 2002 to 2016 were reviewed. Of 2463 cases, 947 (39%) were women. Re-operation risk was defined as any intervention for repair failure or MV disease progression. Median follow-up was 8.2 years.

RESULTS

Women were older with higher STS-risk scores and were more likely to have rheumatic disease (RHD). Operative mortality was clinically higher in women (2.7% vs 1.7%; P = 0.09). Although women had significantly higher 10-year re-operation risk (7% vs 4%), adjusted longitudinal analysis showed that this was associated with RHD in women (HR 4.04; P = 0.001). Female sex alone was not a significant predictor (P = 0.21).

CONCLUSIONS

Re-operation following MV repair was infrequent. Women had increased re-operation risk that was largely attributable to their worse preoperative profiles rather than female sex alone.

Outcomes Before and After the Recall of a Heart Failure Pacemaker

IMPORTANCE

Timely and complete disclosure of medical device defects is necessary to manage patient care safely and effectively.

OBJECTIVES

To determine if the manufacturer's recommendations following the recall of a medical device were timely and complete, the follow-up information and data provided to patients and physicians were adequate for managing patient care, and the actions taken by the US Food and Drug Administration (FDA) regarding the recall were appropriate.

DESIGN, SETTING, AND PARTICIPANTS

This single-center retrospective case series included 90 of 448 patients who were implanted with a cardiac resynchronization therapy pacemaker at the Minneapolis Heart Institute from May 2003 through January 2011; this pacemaker was recalled in November 2015. In addition, returned product reports submitted by the manufacturer to the FDA via the Manufacturer and User Facility Device Experience (MAUDE) database from January 2008 through December 2018 were analyzed.

MAIN OUTCOMES AND MEASURES

Clinical outcomes were serious adverse clinical events that occurred before and after the November 2015 recall notifying physicians and patients that the device's battery could fail unexpectedly because of high internal impedance. Technical outcomes were signs and causes of failure.

RESULTS

Five of 90 patients observed during 2015 experienced syncope when their pacemakers stopped pacing owing to battery or wire connection defects prior to the recall. Of the 90 patients, 37 (41%) were men, and the median (interquartile range) age at implantation was 71.3 (66.1-78.2) years. Analysis of the MAUDE data revealed that battery failures prior to the recall were associated with serious adverse events that included 1 death, 1 cardiac arrest, 5 syncopal attacks, and 6 heart failure exacerbations; 3 additional prerecall syncopal events were caused by wire connection defects. The manufacturer and the FDA were aware of the battery and wire connection defects for 19 months before issuing the recall, yet the wire connection problem was not included in the advisory and physicians were not informed that interrogating the pacemaker could result in loss of pacing. The FDA classified the recall as class II rather than the more critical class I.

CONCLUSIONS AND RELEVANCE

This case series study of patients implanted with a defective pacemaker found that the pacemaker recall was delayed and that subsequent communications did not include all critical information needed for safe and effective patient care. These findings should prompt reforms in how the medical device industry and the FDA manage future medical device recalls.

Immunogenicity of Potomac horse fever vaccine when simultaneously co-administered with rabies vaccine in a multivalent vaccine or as two monovalent vaccines at separate sites

Background

Potomac horse fever (PHF) is a potentially fatal enterocolitis of horses caused by Neorickettsia risticii. The disease was originally recognised almost 40 years ago in the state of Maryland in the US. It is now known to occur in many areas of North America, as well as having been described in South America and Europe. Monocomponent PHF vaccines are available, but clinical protection with vaccination has been reported to be inconsistent.

Objectives

This study was designed to assess the immunogenicity of a commercially available Potomac Horse Fever (PHF) vaccine when administered as either a monovalent PHF vaccine simultaneously co‐administered with a separate monovalent Rabies vaccine or as a multivalent PHF/Rabies vaccine in horses.

Study design

Randomised parallel group trial.

Methods

Ninety‐one client or University owned horses participated in this open‐label randomised study, with 45 horses receiving the monovalent vaccines at separate sites and 46 receiving the multivalent vaccine at a single site. Serum PHF IFA titres were determined twice prior to vaccination and at 1, 2 and 3 months after vaccination.

Results

Both vaccination protocols exhibited poor immunogenicity, with only one‐third of all the animals demonstrating seroconversion, defined as an increase in titre of greater than 400 over baseline, at any time point after vaccination. The monovalent PHF vaccine exhibited significantly greater immunogenicity in terms of the number of horses exhibiting seroconversion, as compared to the multivalent vaccine, at one (20 vs. 11, P = 0.03) and two (18 vs. 9, p = 0.02) months post vaccination. The monovalent PHF vaccine also exhibited significantly greater immunogenicity in terms of the median (interquartile range) IFA titres, as compared to the multivalent vaccine, at one (800 [200–1600] vs. 400 [200–800], P = 0.009) and 2 months (400 [200–1600] vs. 400 [100–800], P = 0.02) post vaccination. There was no significant difference between groups at 3 months in either seroconversion rate or median IFA titers.

Main limitations

This study did not assess the actual protective effects of PHF vaccination but rather used the serologic response to vaccination as a surrogate biomarker of immunity.

Conclusions

The multivalent PHF/Rabies vaccine exhibited lower immunogenicity as compared to the monovalent PHF vaccine co‐administered with a separate Rabies vaccine.

Relevance of immunological parameters in progression of colorectal-carcinoma

The long-term influence on the immunological stage from surgery and/or adjuvant or palliative therapy of 23 patients with metastatic colorectal carcinoma was investigated by performing regular phenotyping and functional analysis of peripheral blood lymphocytes (PBL). The following groups were chosen: A (n=6); patients after resection of primary tumor and liver-metastases without chemotherapy. B (n=3); patients with catheter implantation after resection of primary tumor and liver metastases receiving an adjuvant arterial chemotherapy with 5-fluorouracil (5-FU) and folinic acid (5-formyltetrahydrofolic acid, FA). C (n=7); patients with non-resectable liver-metastases, receiving arterial or systemic chemotherapy after catheter implantation. D (n=7); patients with extrahepatic filiae receiving systemic palliative chemotherapy. Lymphocytes of 10 healthy volunteers served as controls. Furthermore, we were able to show effects of 5-FU and FA on the immune system.