Intimal hyperplasia, saphenous vein graft disease, and clinical outcomes: Insights from the CTSN VEST randomized trial

BACKGROUND

Diffuse intimal hyperplasia and graft irregularity adversely affect the long-term patency of saphenous vein grafts (SVGs) and clinical outcomes of patients undergoing coronary artery bypass grafting (CABG). The VEST trial evaluated the efficacy of external graft support in limiting the development of intimal hyperplasia (IH) at 1 year postsurgery. In the present secondary analysis, we explored the associations between graft disease and IH and clinical events. We also examined risk factors for early graft occlusion.

METHODS

VEST is a within-patient randomized, multicenter trial that enrolled 224 patients with multivessel coronary disease undergoing CABG surgery, of whom 203 were evaluated by 1 year postsurgery. Intimal hyperplasia, lumen uniformity, graft stenosis, and graft perfusion were measured by intravascular ultrasound and angiography. Major cardiac and cerebrovascular events (MACCE; including death, myocardial infarction, stroke, and revascularization) were recorded over a median follow-up of 3 years.

RESULTS

Worse lumen uniformity, greater stenosis, and worse graft perfusion were associated with higher IH values and an increased incidence of clinical events. Consistent with previous findings, we identified endoscopic vein harvesting, female sex, and transit time flow measurement of pulsatility index and flow as risk factors for SVG occlusion during the first year postsurgery.

CONCLUSIONS

In this secondary analysis of the VEST trial, we observed an association between intimal hyperplasia area and clinical measures of SVG disease at 1 year postsurgery. More severe SVG disease and larger areas of IH were associated with a higher incidence of 3-year MACCE. Ongoing follow-up to 5 years will further elucidate the impact of SVG disease on long-term clinical outcomes of CABG.

Permanent Pacemaker Implantation and Long-Term Outcomes of Patients Undergoing Concomitant Mitral and Tricuspid Valve Surgery

BACKGROUND

Tricuspid valve annuloplasty (TA) during mitral valve repair (MVr) is associated with increased risk of permanent pacemaker (PPM) implantation, but the magnitude of risk and long-term clinical consequences have not been firmly established.

OBJECTIVES

This study assesses the incidence rates of PPM implantation after isolated MVr and following MVr with TA as well as the associated long-term clinical consequences of PPM implantation.

METHODS

State-mandated hospital discharge databases of New York and California were queried for patients undergoing MVr (isolated or with concomitant TA) between 2004 and 2019. Patients were stratified by whether or not they received a PPM within 90 days of index surgery. After weighting by propensity score, survival, heart failure hospitalizations (HFHs), endocarditis, stroke, and reoperation were compared between patients with or without PPM.

RESULTS

A total of 32,736 patients underwent isolated MVr (n = 28,003) or MVr + TA (n = 4,733). Annual MVr + TA volumes increased throughout the study period (P < 0.001, trend), and PPM rates decreased (P < 0.001, trend). The incidence of PPM implantation <90 days after surgery was 7.7% for MVr and 14.0% for MVr + TA. In 90-day conditional landmark-weighted analyses, PPMs were associated with reduced long-term survival among MVr (HR: 1.96; 95% CI: 1.75-2.19; P < 0.001) and MVr + TA recipients (HR: 1.65; 95% CI: 1.28-2.14; P < 0.001). In both surgical groups, PPMs were also associated with an increased risk of HFH (HR: 1.56; 95% CI: 1.27-1.90; P < 0.001) and endocarditis (HR: 1.95; 95% CI: 1.52-2.51; P < 0.001), but not with stroke or reoperation.

CONCLUSIONS

Compared to isolated MVr, adding TA to MVr was associated with a higher risk of 90-day PPM implantation. In both surgical groups, PPM implantation was associated with an increase in mortality, HFH, and endocarditis.

Coronary Artery Bypass Grafting in a Patient With Multivessel Disease and Dextrocardia With Situs Inversus Totalis

Dextrocardia with situs inversus totalis is a rare hereditary condition characterized by reversed orientation of the major thoracic and abdominal organs. Though dextrocardia itself is not believed to increase the risk of coronary artery disease, the workup and surgical management of patients with this condition may be technically challenging to heart team clinicians. This report describes the case management of a high-risk 56-year-old man with dextrocardia who presented with multivessel coronary artery disease.

Clinical Trial Diversity, Equity & Inclusion: Roadmap of the Cardiothoracic Surgical Trials Network

BACKGROUND

There is a recognized lack of diversity among patients enrolled in cardiovascular interventional and surgical trials. Diverse patient representation in clinical trials is necessary to enhance generalizability of findings, which may lead to better outcomes across broader populations. The Cardiothoracic Surgical Trials Network (CTSN) recently developed a plan-of-action to increase diversity among participating investigators and trial participants -- the focus of this paper.

METHODS

Review of literature and enrollment data from CTSN trials.

RESULTS

More than a dozen major clinical trials were completed by CTSN (2008-2022), enrolling over 4,000 patients, of whom 30% were women 11% non-White and 5.6% were Hispanic. The Network also completed trials of hospitalized COVID-19 patients, wherein enrollment was more diverse, with 42% women and 58% either Asian, Black, Hispanic or from another underrepresented racial group. The discrepancy in diversity of enrollment between cardiac surgery trials and COVID trials highlights the need for a more comprehensive understanding of: 1) the prevalence of underlying disease requiring cardiac interventions across broad populations, 2) differences in access to care and referral for cardiac surgery, and 3) barriers to enrollment in cardiac surgery trials.

CONCLUSIONS

Committed to diversity, CTSN's multi-faceted action plan includes developing site-specific enrollment targets, collecting social determinants of health data, understanding reasons for non-participation, recruiting sites that serve diverse populations, emphasizing greater diversity among clinical trial teams, and implicit bias training. The CTSN will prospectively assess how these interventions influence enrollment as we work to ensure trial participants are more representative of the communities we serve.

Infarct-related structural disconnection and delirium in surgical aortic valve replacement patients

OBJECTIVE

Although acute brain infarcts are common after surgical aortic valve replacement (SAVR), they are often unassociated with clinical stroke symptoms. The relationship between clinically "silent" infarcts and in-hospital delirium remains uncertain; obscured, in part, by how infarcts have been traditionally summarized as global metrics, independent of location or structural consequence. We sought to determine if infarct location and related structural connectivity changes were associated with postoperative delirium after SAVR.

METHODS

A secondary analysis of a randomized multicenter SAVR trial of embolic protection devices (NCT02389894) was conducted, excluding participants with clinical stroke or incomplete neuroimaging (N = 298; 39% female, 7% non-White, 74 ± 7 years). Delirium during in-hospital recovery was serially screened using the Confusion Assessment Method. Parcellation and tractography atlas-based neuroimaging methods were used to determine infarct locations and cortical connectivity effects. Mixed-effect, zero-inflated gaussian modeling analyses, accounting for brain region-specific infarct characteristics, were conducted to examine for differences within and between groups by delirium status and perioperative neuroprotection device strategy.

RESULTS

23.5% participants experienced postoperative delirium. Delirium was associated with significantly increased lesion volumes in the right cerebellum and temporal lobe white matter, while diffusion weighted imaging infarct-related structural disconnection (DWI-ISD) was observed in frontal and temporal lobe regions (p-FDR < 0.05). Fewer brain regions demonstrated DWI-ISD loss in the suction-based neuroprotection device group, relative to filtration-based device or standard aortic cannula.

INTERPRETATION

Structural disconnection from acute infarcts was greater in patients who experienced postoperative delirium, suggesting that the impact from covert perioperative infarcts may not be as clinically "silent" as commonly assumed.

The Society of Thoracic Surgeons Adult Cardiac Surgery Database: 2023 Update on Procedure Data and Research

The Society of Thoracic Surgeons (STS) Adult Cardiac Surgery Database is one of the largest and most comprehensive contemporary clinical databases in use. It now contains >9 million procedures from 1010 participants and 3651 active surgeons. Using audited data collection, it has provided the foundation for multiple risk models, performance metrics, health policy decisions, and a trove of research studies to improve the care of patients in need of cardiac surgical procedures. This annual report provides an update on the current status of the database and summarizes the development of new risk models and the STS Online Risk Calculator. Further, it provides insights into current practice patterns, such as the change in the demographics among patients undergoing aortic valve replacement, the use of minimally invasive techniques for valve and bypass surgery, or the adoption of surgical ablation and left atrial appendage ligation among patients with atrial fibrillation. Lastly, an overview of the research conducted using the STS Adult Cardiac Surgery Database and future directions for the database are provided.

Racial and Ethnic Disparities in Perioperative Health Care Among Patients Undergoing Cardiac Surgery: JACC State-of-the-Art Review

There has been little progress in reducing health care disparities since the 2003 landmark Institute of Medicine's report Unequal Treatment. Despite the higher burden of cardiovascular disease in underrepresented racial and ethnic groups, they have less access to cardiologists and cardiothoracic surgeons, and have higher rates of morbidity and mortality with cardiac surgical interventions. This review summarizes existing literature and highlights disparities in cardiovascular perioperative health care. We propose actionable solutions utilizing multidisciplinary perspectives from cardiology, cardiac surgery, cardiothoracic anesthesiology, critical care, medical ethics, and health disparity experts. Applying a health equity lens to multipronged interventions is necessary to eliminate the disparities in perioperative health care among patients undergoing cardiac surgery.

Why Are We Weighting? Understanding the Estimates From Propensity Score Weighting and Matching Methods

BACKGROUND

Propensity score methods are used in observational studies to compensate for the lack of random allocation by balancing measured baseline characteristics between treated and untreated patients. We sought to explain the treatment effect estimates derived from different propensity score methods.

METHODS

We performed a retrospective analysis of long-term mortality after single internal mammary artery versus bilateral internal mammary artery (BIMA) conduit in 47 984 index isolated coronary artery bypass grafting procedures from 1992 to 2014 in the Northern New England Cardiovascular Disease Study Group registry using multivariable Cox regression, 1:1 propensity score matching, inverse probability weighting (IPW) among the treated, and IPW among the overall population treatment estimates.

RESULTS

The mean duration of follow-up was 13.2 (interquartile range, 7.4-17.7) years. In multivariable Cox regression, the adjusted hazard ratio for mortality was 0.83 (95% CI, 0.75-0.92) in patients receiving BIMA compared with a single internal mammary artery. The 1:1 propensity matched (hazard ratio, 0.79 [95% CI, 0.69-0.91]) and IPW among the treated (hazard ratio, 0.83 [95% CI, 0.75-0.92]) estimates showed a protective treatment effect of BIMA use on mortality. However, the IPW estimate of treatment effect for the overall population showed an increased risk of mortality after BIMA that was not statistically significant (hazard ratio, 1.08 [95% CI, 0.94-1.24]).

CONCLUSIONS

While the multivariable Cox regression, 1:1 propensity matching, and IPW treatment effect in the treated estimates demonstrate that BIMA was associated with a statistically significantly decreased risk of mortality, the IPW treatment effect in the average study population showed an increased risk of mortality associated with BIMA that was not statistically significant. This is attributed to the different populations (weighted to look like the overall study population versus treated group) represented by the 2 IPW approaches. Determining how the study population is balanced is a large driver of the treatment effect. Ultimately, the treatment effect estimate desired should drive the choice of the propensity score method.

Long-Term Outcomes of Bovine versus Porcine Mitral Valve Replacement: A Multicenter Analysis

Introduction

Recent national guidelines recommending mitral valve replacement (MVR) for severe secondary mitral regurgitation have resulted in an increased utilization of mitral bioprosthesis. There is a paucity of data on how longitudinal clinical outcomes vary by prosthesis type. We examined long-term survival and risk of reoperation between patients having bovine vs. porcine MVR. Study Design. A retrospective analysis of MVR or MVR + coronary artery bypass graft (CABG) from 2001 to 2017 among seven hospitals reporting to a prospectively maintained clinical registry was conducted. The analytic cohort included 1,284 patients undergoing MVR (801 bovine and 483 porcine). Baseline comorbidities were balanced using 1 : 1 propensity score matching with 432 patients in each group. The primary end point was all-cause mortality. Secondary end points included in-hospital morbidity, 30-day mortality, length of stay, and risk of reoperation.

Results

In the overall cohort, patients receiving porcine valves were more likely to have diabetes (19% bovine vs. 29% porcine; p < 0.001), COPD (20% bovine vs. 27% porcine; p=0.008), dialysis or creatinine >2 mg/dL (4% bovine vs. 7% porcine; p=0.03), and coronary artery disease (65% bovine vs. 77% porcine; p < 0.001). There was no difference in stroke, acute kidney injury, mediastinitis, pneumonia, length of stay, in-hospital morbidity, or 30-day mortality. In the overall cohort, there was a difference in long-term survival (porcine HR 1.17 (95% CI: 1.00-1.37; p=050)). However, there was no difference in reoperation (porcine HR 0.56 (95% CI: 0.23-1.32; p=0.185)). In the propensity-matched cohort, patients were matched on all baseline characteristics. There was no difference in postoperative complications or in-hospital morbidity and 30-day mortality. After 1 : 1 propensity score matching, there was no difference in long-term survival (porcine HR 0.97 (95% CI: 0.81-1.17; p=0.756)) or risk of reoperation (porcine HR 0.54 (95% CI: 0.20-1.47; p=0.225)).

Conclusions

In this multicenter analysis of patients undergoing bioprosthetic MVR, there was no difference in perioperative complications and risk of reoperation of long-term survival after matching.

A Randomized Trial of Mesenchymal Stromal Cells for Moderate to Severe Acute Respiratory Distress Syndrome from COVID-19

Rationale: There are limited therapeutic options for patients with coronavirus disease (COVID-19)-related acute respiratory distress syndrome with inflammation-mediated lung injury. Mesenchymal stromal cells offer promise as immunomodulatory agents. Objectives: Evaluation of efficacy and safety of allogeneic mesenchymal cells in mechanically-ventilated patients with moderate or severe COVID-19-induced respiratory failure. Methods: Patients were randomized to two infusions of 2 million cells/kg or sham infusions, in addition to the standard of care. We hypothesized that cell therapy would be superior to sham control for the primary endpoint of 30-day mortality. The key secondary endpoint was ventilator-free survival within 60 days, accounting for deaths and withdrawals in a ranked analysis. Measurements and Main Results: At the third interim analysis, the data and safety monitoring board recommended that the trial halt enrollment as the prespecified mortality reduction from 40% to 23% was unlikely to be achieved (n = 222 out of planned 300). Thirty-day mortality was 37.5% (42/112) in cell recipients versus 42.7% (47/110) in control patients (relative risk [RR], 0.88; 95% confidence interval, 0.64-1.21; P = 0.43). There were no significant differences in days alive off ventilation within 60 days (median rank, 117.3 [interquartile range, 60.0-169.5] in cell patients and 102.0 [interquartile range, 54.0-162.5] in control subjects; higher is better). Resolution or improvement of acute respiratory distress syndrome at 30 days was observed in 51/104 (49.0%) cell recipients and 46/106 (43.4%) control patients (odds ratio, 1.36; 95% confidence interval, 0.57-3.21). There were no infusion-related toxicities and overall serious adverse events over 30 days were similar. Conclusions: Mesenchymal cells, while safe, did not improve 30-day survival or 60-day ventilator-free days in patients with moderate and/or severe COVID-19-related acute respiratory distress syndrome.

Pacemaker implantation associated with tricuspid repair in the setting of mitral valve surgery: Insights from a Cardiothoracic Surgical Trials Network randomized trial

OBJECTIVES

In a recent trial, tricuspid annuloplasty (TA) during mitral valve surgery (MVS) for degenerative mitral regurgitation and moderate or less tricuspid regurgitation (TR) reduced the composite rate of death, reoperation for TR, or TR progression at 2 years. However, this benefit was counterbalanced by an increase in implantation of permanent pacemakers (PPMs). In this study, we analyzed the timing, indications, and risk factors for these implantations.

METHODS

We randomized 401 patients (MVS alone = 203; MVS + TA = 198). Potential risk factors for PPMs were assessed using multivariable time-to-event models with death and PPM implantation for heart failure indications as competing risks.

RESULTS

A PPM was implanted in 36 patients (9.6; 95% CI, 6.8-13.0) within 2 years of randomization, with 30/187 (16.0%) in the MVS + TA and 6/188 (3.2%) in the MVS groups (rate ratio, 5.08; 95% CI, 2.16-11.94; P < .001). Most (29/36; 80.6%) implantations occurred within 30 days postoperatively. Independent risk factors for PPM implantation within 2 years were TA (hazard ratio [HR], 5.94; 95% CI, 2.27-15.53; P < .001), increasing age (5 years, HR, 1.23; 95% CI, 1.01-1.52; P = .04), and left ventricular ejection fraction (LVEF; HR, 0.96; 95% CI, 0.92-0.99; P = .02). In the subset of TA recipients (n = 197), age (5 years, HR, 1.05; 95% CI, 1.00-1.10; P = .04) and LVEF (HR, 0.95; 95% CI, 0.91-0.99; P = .01) were associated with PPM within 2 years.

CONCLUSIONS

Concomitant TA, age, and baseline LVEF were risk factors for PPM implantation in patients who underwent MVS for degenerative mitral regurgitation. Although TA was effective in preventing progression of TR, innovation is needed to identify ways to decrease PPM implantation rates.

Multicenter experience with valve-in-valve transcatheter aortic valve replacement compared with primary, native valve transcatheter aortic valve replacement

BACKGROUND

Valve-in-valve (ViV) transcatheter aortic valve replacement (TAVR) offers an alternative to reoperative surgical aortic valve replacement. The short- and intermediate-term outcomes after ViV TAVR in the real world are not entirely clear.

PATIENTS AND METHODS

A multicenter, retrospective analysis of a consecutive series of 121 ViV TAVR patients and 2200 patients undergoing primary native valve TAVR from 2012 to 2017 at six medical centers. The main outcome measures were in-hospital mortality, 30-day mortality, stroke, myocardial infarction, acute kidney injury, and pacemaker implantation.

RESULTS

ViV patients were more likely male, younger, prior coronary artery bypass graft, "hostile chest," and urgent. 30% of the patients had Society of Thoracic Surgeons risk score <4%, 36.3% were 4%-8% and 33.8% were >8%. In both groups many patients had concomitant coronary artery disease. Median time to prosthetic failure was 9.6 years (interquartile range: 5.5-13.5 years). 82% of failed surgical valves were size 21, 23, or 25 mm. Access was 91% femoral. After ViV, 87% had none or trivial aortic regurgitation. Mean gradients were <20 mmHg in 54.6%, 20-29 mmHg in 30.6%, 30-39 mmHg in 8.3% and ≥40 mmHg in 5.87%. Median length of stay was 4 days. In-hospital mortality was 0%. 30-day mortality was 0% in ViV and 3.7% in native TAVR. There was no difference in in-hospital mortality, postprocedure myocardial infarction, stroke, or acute kidney injury.

CONCLUSION

Compared to native TAVR, ViV TAVR has similar peri-procedural morbidity with relatively high postprocedure mean gradients. A multidisciplinary approach will help ensure patients receive the ideal therapy in the setting of structural bioprosthetic valve degeneration.

External Support for Saphenous Vein Grafts in Coronary Artery Bypass Surgery: A Randomized Clinical Trial

Importance

Intimal hyperplasia and subsequent saphenous vein graft failure may have significant adverse clinical effects in patients undergoing coronary artery bypass surgery. External support of saphenous vein grafts has the potential to prevent vein graft dilation and hence slow the rate of intimal hyperplasia and increase long-term vein patency.

Objective

To determine efficacy, as measured by intimal hyperplasia, and safety of an external saphenous vein graft support device in patients undergoing a coronary bypass graft procedure.

Design, Setting, and Participants

This within-patient randomized, open-label, multicenter study was conducted at 17 Cardiothoracic Surgical Trials Network centers in North America. Between January 2018 and February 2019, 224 patients with multivessel coronary artery disease undergoing isolated bypass surgery were enrolled. For each patient, 1 of 2 vein grafts was randomized to receive external support or no support.

Interventions

External vein graft support or no support.

Main Outcomes and Measures

The primary efficacy end point was intimal hyperplasia area assessed by intravascular ultrasound at 12 months postrandomization for each study graft. Secondary confirmatory end points were lumen diameter uniformity assessed by angiography and graft failure (≥50% stenosis) by quantitative coronary angiography. Major cardiac and cerebrovascular events were collected through month 12.

Results

Among 224 patients (mean [SD] age, 65.8 [8.3] years; 178 [79.5%] male), 203 (90.6%) were eligible for intravascular ultrasound, of which 85 (41.9%) had at least 1 study graft occluded or severely diseased at 12 months (55 supported, 56 unsupported). After imputation of data missing because of graft occlusion or severe disease, the estimated mean (SE) intimal hyperplasia area was 5.11 (0.16) mm2 in supported grafts and 5.79 (0.20) mm2 in unsupported grafts (P = .07). In a sensitivity analysis of 113 patients with both grafts imaged, the mean intimal hyperplasia area was 4.58 (0.18) mm2 and 5.12 (0.23) mm2 in supported and unsupported grafts, respectively (P = .04). By 12 months, 5 patients (2.2%) died and 16 patients (7.1%) experienced a major cardiac or cerebrovascular event.

Conclusions and Relevance

The 12-month difference in intimal hyperplasia area between supported and unsupported grafts did not achieve statistical significance. Cumulative mortality and major cardiac or cerebrovascular events rates were similar to those in other randomized coronary artery bypass trials. Further investigation to assess the effect of external graft support devices on long-term graft patency and clinical outcomes is warranted.

Trial Registration

ClinicalTrials.gov Identifier: NCT03209609.

Concordance of Guideline-Based Risk Stratification and Selection of Patients for Transcatheter Aortic Valve Implantation or Surgical Replacement

The 2020 American Health Association/American College of Cardiology valve guidelines recommend surgical aortic valve replacement (SAVR) for symptomatic patients with aortic stenosis (AS) age <65 years and transcatheter aortic valve implantation (TAVI) for patients with AS age >80 years. We analyzed TAVI versus SAVR practice patterns using age-based recommendations. We compared 2016-to-2019 TAVI and isolated SAVR in northern New England at 5 centers according to guideline-recommended age groups. Multivariable logistic regression was performed to identify independent predictors of TAVI for the intermediate age group. The study was approved by each site's institutional review board in accordance with ongoing participation and quality improvement efforts in the Northern New England Cardiovascular Study Group. Among 4,161 patients with isolated severe AS, TAVI increased from 2016 to 2019: 55.8% versus 76.1%, p <0.01 for trend. SAVR for patients with AS age >80 years was uncommon and decreased over time: 13.1% versus 1.6%, p <0.01. TAVI utilization nearly doubled over time in young patients with AS age <65 years (14.3% vs 26.2%, p <0.01). Preference for SAVR decreased by 50% over time (p <0.01) in the intermediate age group (65 to 80 years). Independent predictors of TAVI among patients aged 65 to 80 years included older age, chronic obstructive pulmonary disease, previous stroke, and coronary artery bypass grafting, whereas vascular disease and clinical urgency favored SAVR. In conclusion, consistent with current American Health Association/American College of Cardiology guidelines, TAVI was the treatment of choice in >97% of severe patients with AS age >80 years by 2019. TAVI utilization in patients <65 years has doubled over time and thus may not reflect current guideline recommendations. TAVI is the preferred choice in those aged 65 to 80 years, especially among patients with previous stroke or coronary artery bypass grafting.

Concomitant Tricuspid Repair in Patients with Degenerative Mitral Regurgitation

BACKGROUND

Tricuspid regurgitation is common in patients with severe degenerative mitral regurgitation. However, the evidence base is insufficient to inform a decision about whether to perform tricuspid-valve repair during mitral-valve surgery in patients who have moderate tricuspid regurgitation or less-than-moderate regurgitation with annular dilatation.

METHODS

We randomly assigned 401 patients who were undergoing mitral-valve surgery for degenerative mitral regurgitation to receive a procedure with or without tricuspid annuloplasty (TA). The primary 2-year end point was a composite of reoperation for tricuspid regurgitation, progression of tricuspid regurgitation by two grades from baseline or the presence of severe tricuspid regurgitation, or death.

RESULTS

Patients who underwent mitral-valve surgery plus TA had fewer primary-end-point events than those who underwent mitral-valve surgery alone (3.9% vs. 10.2%) (relative risk, 0.37; 95% confidence interval [CI], 0.16 to 0.86; P = 0.02). Two-year mortality was 3.2% in the surgery-plus-TA group and 4.5% in the surgery-alone group (relative risk, 0.69; 95% CI, 0.25 to 1.88). The 2-year prevalence of progression of tricuspid regurgitation was lower in the surgery-plus-TA group than in the surgery-alone group (0.6% vs. 6.1%; relative risk, 0.09; 95% CI, 0.01 to 0.69). The frequencies of major adverse cardiac and cerebrovascular events, functional status, and quality of life were similar in the two groups at 2 years, although the incidence of permanent pacemaker implantation was higher in the surgery-plus-TA group than in the surgery-alone group (14.1% vs. 2.5%; rate ratio, 5.75; 95% CI, 2.27 to 14.60).

CONCLUSIONS

Among patients undergoing mitral-valve surgery, those who also received TA had a lower incidence of a primary-end-point event than those who underwent mitral-valve surgery alone at 2 years, a reduction that was driven by less frequent progression to severe tricuspid regurgitation. Tricuspid repair resulted in more frequent permanent pacemaker implantation. Whether reduced progression of tricuspid regurgitation results in long-term clinical benefit can be determined only with longer follow-up. (Funded by the National Heart, Lung, and Blood Institute and the German Center for Cardiovascular Research; ClinicalTrials.gov number, NCT02675244.).

Geographic and Demographic Variability in Transcatheter Aortic Valve Replacement Dispersion in the United States

Background

Transcatheter aortic valve replacement (TAVR) has transformed the management of aortic valve stenosis. However, little national data are available characterizing the geographic and demographic dispersion of this disruptive technology relative to surgical aortic valve replacement (SAVR).

Methods and Results

In this US claims‐based study, we analyzed a 100% sample of fee‐for‐service Medicare beneficiaries from 2012 to 2017 and examined national rates of TAVR versus SAVR. Procedure rates were compared across years as a function of age, sex, race, and geography for TAVR and SAVR beneficiaries. There was significant growth in TAVR from 15.4 beneficiaries/100 000 enrollees in 2012 to 90.6 in 2017 (P<0.001). SAVR rates declined from 92.8 beneficiaries/100 000 enrollees in 2012 to 63.5 in 2017 (P<0.001). The growth of TAVR varied as a function of age (P<0.0001). While TAVR was the dominant strategy among beneficiaries ≥85 and 75 to 84 years old, SAVR was more common among beneficiaries 65 to 74 years old. TAVR was also used more frequently than SAVR among women (P<0.001). While TAVR increased among all races, it was less commonly used among non‐White beneficiaries (P<0.001). Contemporary use of TAVR relative to SAVR varied significantly by geographic location, with a TAVR:SAVR ratio in 2017 of 1.24 in the Midwest and 1.68 in the Northeast (P<0.001).

Conclusions

In 2017, the number of Medicare beneficiaries receiving TAVR exceeded SAVR for the first time in the United States. There is significant variation, however, in the geographic expansion of TAVR and in patient demographics relative to SAVR.

Percutaneous management strategies for STEMI with coexisting aneurysmal coronary- to-pulmonary artery fistula: a case report

Background

Coexistence of coronary artery fistulas and atherosclerotic coronary artery disease (CAD) is rare.

Case summary

We present a unique case of a patient initially presenting with an anterior ST-elevation myocardial infarction, subsequently found to have two-vessel CAD and an aneurysmal left coronary-to-right pulmonary artery fistula.

Discussion

After discussion with the patient and a multidisciplinary discussion with the heart team, consisting of cardiovascular surgery, interventional cardiology, and vascular surgery, a percutaneous approach was chosen. He underwent successful multivessel percutaneous coronary intervention followed by fistula embolization.

Cardiac Surgery Outcomes: A Case for Increased Screening and Treatment of Obstructive Sleep Apnea

BACKGROUND

Due to the limited published information on complications that obstructive sleep apnea (OSA) patients experience during and after cardiac surgery, we are investigating OSA as a risk factor for post-operative outcomes.

METHODS

This project utilized the Northern New England Cardiovascular Disease Study Group's data collected between 2011 and 2017 based on the Society of Thoracic Surgeons Adult Cardiac Surgery Database Data Collections form. A retrospective analysis of 1,555 patients with OSA and 10,450 patients without OSA, across 5 medical centers undergoing isolated CABG, isolated valve, combined CABG valve surgery was conducted. We used 1:1 nearest neighbor propensity score matching with no replacement to balance characteristics among patients with and without OSA.

RESULTS

There was a statistically significant increased risk of post-operative pneumonia, increased length of total and post-operative stay, and time to initial extubation. Two outcomes trended towards significance: intra- and post-operative IABP use. Outcomes that failed to show statistical significance included: surgical site infection, atrial fibrillation cerebrovascular accident, permanent pacemaker placement, and blood products given. A chart review conducted on a subset of the study cohort revealed that more than 40% of OSA patients did not receive CPAP or BiPAP therapy post-operatively during their hospitalization.

CONCLUSIONS

Our study aligns with the literature in concluding that OSA has deleterious effects on post-operative outcomes of cardiac surgery patients. Further research to better stratify OSA patients by severity are still needed. Additionally, heightened awareness of the need to screen, diagnose, and properly treat patients for OSA is needed.

Cardiac surgery considerations and lessons learned during the COVID‐19 pandemic

The COVID‐19 pandemic has transformed cardiac surgical practices. Limitations in intensive care resources and personal protective equipment have required many practices throughout the globe to pause elective operations and now slowly resume operations. However, much of cardiac surgery is not elective and patients continue to require surgery on an urgent or emergent basis during the pandemic. This continued need for providing surgical services has introduced several unique considerations ranging from how to prioritize surgery, how to ensure safety for cardiac surgical teams, and how best to resume elective operations to ensure the safety of patients. Additionally, the COVID‐19 pandemic has required a careful analysis of how best to carry out heart transplantation, extra‐corporeal membrane oxygenation, and congenital heart surgery. In this review, we present the many areas of multidisciplinary consideration, and the lessons learned that have allowed us to carry out cardiac surgery with excellence during the COVID‐19 pandemic. As various states experience plateaus, declines, and rises in COVID‐19 cases, these considerations are particularly important for cardiac surgical programs throughout the globe.

Incidence and Risk Factors for Permanent Pacemaker Implantation Following Mitral or Aortic Valve Surgery

BACKGROUND

Risk factors for post-operative conduction disturbances after cardiac valve surgery requiring a permanent pacemaker (PPM) are poorly characterized.

OBJECTIVES

The aim of this study was to investigate the timing and risk factors for PPM implantation after mitral or aortic valve surgery.

METHODS

All patients who underwent open aortic or mitral valve surgery between January 1996 and December 2014 were reviewed using New York State's mandatory hospital discharge database. Patients with prior cardiac surgery or pre-existing PPM were excluded. The primary endpoint was PPM implantation within 1 year.

RESULTS

Among 77,882 patients, 63.8% (n = 49,706) underwent aortic valve replacement (AVR), 18.9% (n = 14,686) underwent mitral valve replacement (MVR), 10.5% (n = 8,219) underwent mitral valve repair (MVr), 5.4% (n = 4,202) underwent AVR plus MVR, and 1.4% (n = 1,069) underwent AVR plus MVr. The 1-year PPM implantation rate was 4.5% after MVr, 6.6% after AVR, 9.3% after AVR plus MVr, 10.5% after MVR, and 13.3% after AVR plus MVR (p < 0.001). Across all groups, the majority of PPMs were implanted during the index hospitalization (79.9%). MVr was associated with the lowest risk for PPM and AVR plus MVR with the highest risk. Older age, history of arrhythmias, pre-operative conduction disturbances, and concomitant index procedures were associated with increased risk for PPM during the index hospitalization. Conversely, beyond 30 days, chronic comorbidities were associated with increased risk for PPM.

CONCLUSIONS

Conduction disturbances requiring PPM remain a common adverse event after valve surgery. Identifying patients at risk for PPM will help facilitate perioperative planning and inform clinical decision making regarding post-operative rhythm surveillance.

Pacemaker Implantation After Mitral Valve Surgery With Atrial Fibrillation Ablation

BACKGROUND

The incidence of permanent pacemaker (PPM) implantation is higher following mitral valve surgery (MVS) with ablation for atrial fibrillation (AF) compared with MVS alone.

OBJECTIVES

This study identified risk factors and outcomes associated with PPM implantation in a randomized trial that evaluated ablation for AF in patients who underwent MVS.

METHODS

A total of 243 patients with AF and without previous PPM placement were randomly assigned to MVS alone (n = 117) or MVS + ablation (n = 126). Patients in the ablation group were further randomized to pulmonary vein isolation (PVI) (n = 62) or the biatrial maze procedure (n = 64). Using competing risk models, this study examined the association among PPM and baseline and operative risk factors, and the effect of PPM on time to discharge, readmissions, and 1-year mortality.

RESULTS

Thirty-five patients received a PPM within the first year (14.4%), 29 (83%) underwent implantation during the index hospitalization. The frequency of PPM implantation was 7.7% in patients randomized to MVS alone, 16.1% in MVS + PVI, and 25% in MVS + biatrial maze. The indications for PPM were similar among patients who underwent MVS with and without ablation. Ablation, multivalve surgery, and New York Heart Association functional (NYHA) functional class III/IV were independent risk factors for PPM implantation. Length of stay post-surgery was longer in patients who received PPMs, but it was not significant when adjusted for randomization assignment (MVS vs. ablation) and age (hazard ratio [HR]: 0.81; 95% confidence interval [CI]: 0.61 to 1.08; p = 0.14). PPM implantation did not increase 30-day readmission rate (HR: 1.43; 95% CI: 0.50 to 4.05; p = 0.50). The need for PPM was associated with a higher risk of 1-year mortality (HR: 3.21; 95% CI: 1.01 to 10.17; p = 0.05) after adjustment for randomization assignment, age, and NYHA functional class.

CONCLUSIONS

AF ablation, multivalve surgery, and NYHA functional class III/IV were associated with an increased risk for permanent pacing. PPM implantation following MVS was associated with a significant increase in 1-year mortality. (Surgical Ablation Versus No Surgical Ablation for Patients With Atrial Fibrillation Undergoing Mitral Valve Surgery; NCT00903370).

Acute Kidney Recovery in Patients Who Underwent Transcatheter Versus Surgical Aortic Valve Replacement (from the Northern New England Cardiovascular Disease Study Group)

Acute kidney recovery (AKR) is a recently described phenomenon observed after transcatheter aortic valve replacement (TAVR) and is more frequent than acute kidney injury (AKI). To determine the incidence and predictors of AKR between surgical aortic valve replacement (SAVR) and TAVR, we examined patients with chronic kidney disease and severe aortic stenosis who underwent SAVR or TAVR procedure between 2007 and 2017; excluding age <65 or >90, dialysis, endocarditis, non-aortic valve stenosis, or patients died within 48-hours postprocedure. AKR was defined as an increase of estimated glomerular filtration rate (eGFR) >25% and AKI as decrease in eGFR >25% at discharge. Stroke, mortality, major bleeding, transfusion, and length of stay were examined. Multivariate logistic regression analysis was used to examine predictors of AKR. There were 750 transcatheter and 1,062 surgical patients and 319 pairs after propensity matching. AKR was observed in 26% TAVR versus 23.2% SAVR, p = 0.062. Highest recovery was in patients with eGFR <30 for both TAVR (33.7%) and SAVR (34.5%) patients. Independent predictors of AKR were ejection fraction <50% (odds ratio [OR] 1.66, 95% confidence interval [CI] 1.02 to 2.71, p = 0.042), female gender (OR 1.66, 95% CI 1.1 to 2.5, p = 0.015), and obesity (OR 1.5, 95% CI 1.04-2.3, p = 0.032). Diabetes was a negative predictor of AKR (OR 0.55, 95% CI 0.36 to 0.84, p = 0.005). AKR was associated with improved secondary clinical outcomes compared with AKI. In conclusion, AKR is a generalizable phenomenon occurring frequently and similarly among transcatheter or surgical aortic valve patients. Diabetes is a negative predictor of AKR, possibly indicative of less reversible kidney disease.

Impact of Aortic Atherosclerosis Burden on Outcomes of Surgical Aortic Valve Replacement

BACKGROUND

Epiaortic ultrasound detects and localizes ascending aortic atherosclerosis. In this analysis we investigated the association between epiaortic ultrasound-based atheroma grade during surgical aortic valve replacement (SAVR) and perioperative adverse outcomes.

METHODS

SAVR patients in a randomized trial of 2 embolic protection devices underwent a protocol-defined 5-view epiaortic ultrasound read at a core laboratory. Aortic atherosclerosis was quantified with the Katz atheroma grade, and patients were categorized as mild (grade I-II) or moderate/severe (grade III-V). Multivariable logistic regression was used to estimate associations between atheroma grade and adverse outcomes, including death, clinically apparent stroke, cerebral infarction on diffusion-weighted magnetic resonance imaging, delirium, and acute kidney injury (AKI) by 7 and 30 days.

RESULTS

Precannulation epiaortic ultrasound data were available for 326 of 383 randomized patients (85.1%). Of these, 106 (32.5%) had moderate/severe Katz atheroma grade at any segment of the ascending aorta. Although differences in the composite of death, stroke, or cerebral infarction on diffusion-weighted magnetic resonance imaging by 7 days were not statistically significant, moderate/severe atheroma grade was associated with a greater risk of AKI by 7 days (adjusted odds ratio, 2.63; 95% confidence interval, 1.24-5.58; P = .01). At 30 days, patients with moderate/severe atheroma grade had a greater risk of death, stroke, or AKI (adjusted odds ratio, 1.97; 95% confidence interval, 1.04-3.71; P = .04).

CONCLUSIONS

Moderate/severe aortic atherosclerosis was associated with an increased risk of adverse events after SAVR. Epiaortic ultrasound may serve as a useful adjunct for identifying patients who may benefit from strategies to reduce atheroembolic complications during SAVR.

Abstract 171: User Beware: Understanding the Adjusted Estimates of Propensity Score Methods

Background: Propensity score methods are used in observational studies to compensate for the lack of random allocation by balancing measured baseline characteristics between treated and untreated patients. Yet default implementations of propensity score methods may lead to contradictory findings. Our goal was to illustrate differences in treatment effect estimates produced using propensity score methods such as matching and inverse probability weighting (IPW).

Methods: We used data from a retrospective analysis of the Northern New England Cardiovascular Disease Study Group registry that studied reintervention after single internal mammary artery (SIMA) versus bilateral internal mammary artery (BIMA) conduit use in 41,481 coronary artery bypass grafting (CABG) procedures from 1992-2014.

Results: The mean duration of follow-up was 13.2 (IQR: 7.4-17.7) years. In our standard multivariable Cox regression analysis, the adjusted HR for reintervention was 0.83 (95% confidence interval (CI): 0.75-0.92) in patients receiving BIMA compared to SIMA (Table). The 1:1 propensity matched analysis (HR=0.79, 95% CI: 0.69-0.91) and IPW estimate among the treated (HR=0.83, 95% CI: 0.75-0.92) show a similar protective treatment effect of BIMA use on reintervention. However, the IPW approach for the overall population effect unusually showed no difference between BIMA and SIMA on reintervention-free survival (HR=1.08, 95% CI: 0.94-1.24).

Conclusions and Relevance: The adjusted HR for reintervention after BIMA versus SIMA use in CABG was remarkably different for the two IPW estimates. This difference is attributed to the population represented by the two IPW approaches- the IPW among the treated estimate represents the effect in the average study population, whereas the IPW in the treated represents the effect in the treated population alone. Determining how the study population is balanced (weighted to look like the overall study population versus treated group) is a large driver of treatment effect, and a key element of propensity score methods. Ultimately, the treatment effect estimate desired should drive the choice of propensity score adjustment method.

Intensity of Glycemic Control Affects Long-Term Survival After Coronary Artery Bypass Graft Surgery

BACKGROUND

A patient's hemoglobin (Hb) A_1c level, regardless of diabetic status, is a measure of glycemic control. Studies have found it is an independent predictor of short-term death in patients undergoing coronary artery bypass grafting (CABG). In this study, we used preoperative HbA_1c to assess whether levels are associated with short-term and long-term survival after CABG.

METHODS

From a regional registry of consecutive cases, we identified 6,415 patients undergoing on-pump isolated CABG from 2008 to 2015 with documented preoperative HbA_1c level. We defined four HbA_1c groups: less than 5.7% (n = 1,713), 5.7% to 6.4% (n = 2,505), 6.5% to 8.0% (n = 1,377), and more than 8% (n = 820). Relationship to in-hospital outcomes and long-term survival was assessed. Outcome rates and hazard ratios were adjusted for patient and disease risk factors using multivariable logistic regression and Cox models.

RESULTS

The study included 3,740 patients (58%) not diagnosed as having diabetes and 2,674 with diabetes. Prediabetes (HbA_1c 5.7% to 6.4%) was documented in 52% (n = 1,933) of nondiabetic patients. Higher HbA_1c values were associated with younger age, female sex, greater body mass index, more comorbid diseases, lower ejection fraction, more 3-vessel coronary disease, and recent myocardial infarction (p < 0.05 trend for all). After adjustment for patient risk, greater HbA_1c values were not associated with higher rates of in-hospital death or morbidity. Long-term survival was significantly worse as HbA_1c increased. Risk of death increased by 13% for every unit increase in HbA_1c (adjusted hazard ratio, 1.13; 95% confidence interval, 1.07 to 1.19; p < 0.001).

CONCLUSIONS

Preadmission glycemic control, as assessed by HbA_1c, is predictive of long-term survival, with higher levels associated with poorer prognosis. Whether this risk can be modified by better glycemic control postoperatively remains to be determined.

A multi-institutional cohort study confirming the risks of Clostridium difficile infection associated with prolonged antibiotic prophylaxis

OBJECTIVES

The incidence and severity of Clostridium difficile infection (CDI) have increased rapidly over the past 2 decades, particularly in elderly patients with multiple comorbidities. This study sought to characterize the incidence and risks of these infections in cardiac surgery patients.

METHODS

A total of 5158 patients at 10 Cardiothoracic Surgical Trials Network sites in the US and Canada participated in a prospective study of major infections after cardiac surgery. Patients were followed for infection, readmission, reoperation, or death up to 65 days after surgery. We compared clinical and demographic characteristics, surgical data, management practices, and outcomes for patients with CDI and without CDI.

RESULTS

C difficile was the third most common infection observed (0.97%) and was more common in patients with preoperative comorbidities and complex operations. Antibiotic prophylaxis for >2 days, intensive care unit stay >2 days, and postoperative hyperglycemia were associated with increased risk of CDI. The median time to onset was 17 days; 48% of infections occurred after discharge. The additional length of stay due to infection was 12 days. The readmission and mortality rates were 3-fold and 5-fold higher, respectively, in patients with CDI compared with uninfected patients.

CONCLUSIONS

In this large multicenter prospective study of major infections following cardiac surgery, CDI was encountered in nearly 1% of patients, was frequently diagnosed postdischarge, and was associated with extended length of stay and substantially increased mortality. Patients with comorbidities, longer surgery time, extended antibiotic exposure, and/or hyperglycemic episodes were at increased risk for CDI.

The evolution of minimally invasive cardiac surgery: from minimal access to transcatheter approaches

The field of minimally invasive cardiac surgery has undergone rapid transformation over recent years. In this review, we provide a summary of the most current evidence supporting the use of minimally invasive aortic and mitral valve replacement techniques, as well as transcatheter approaches for aortic and mitral valve disease. As an adjunct, the use of robotically assisted coronary bypass surgery and hybrid coronary revascularization procedures is discussed. In order to obtain optimal patient outcomes, a collaborative, heart-team approach between cardiac surgeons and interventional cardiologists is necessary.

National Trends and Geographic Variation in Bilateral Internal Mammary Artery Use in the United States

BACKGROUND

The goal of this study was to characterize the adoption rate and regional variation in bilateral internal mammary artery (BIMA) use during coronary artery bypass grafting (CABG) in the United States.

METHODS

Observational study of 100% sample of fee-for-service Medicare beneficiaries aged 65 years or older, continuously enrolled in Parts A and B from 2009 to 2014 (n = 162,860,439). Rates of beneficiaries receiving a BIMA versus single internal mammary artery (SIMA) during CABG are expressed per 1,000 beneficiaries and aggregated by Hospital Referral Region (HRR). An HRR is a validated unit for quantifying regional variation in health care.

RESULTS

The absolute national rate of BIMA use declined during the study period from 0.21 claims per 1,000 beneficiaries in 2009 to 0.13 in 2014 (p < 0.001). When indexed to overall CABG volume, no change was seen in the frequency of BIMA use over time (p = 0.883). SIMA use ranged from 1.3 to 8.5 claims per 1,000 Medicare beneficiaries, whereas BIMA use ranged from 0 to 1.5 (p < 0.001). A significant correlation was found between regional volume of SIMA use and likelihood of BIMA use (correlation coefficient 0.673, p < 0.001). Although both SIMA and BIMA use correlated with regional volume of diagnostic cardiac catheterization, the correlation was stronger for SIMA use (correlation coefficient 0.962 versus 0.682, p < 0.001).

CONCLUSIONS

Over the past 5 years, no growth was seen in BIMA use among Medicare beneficiaries, and the frequency of BIMA use during CABG remained low. There was significant regional variation in BIMA use, however, which demonstrates opportunity for continued growth of BIMA grafting.