Impact of Moderate Aortic Stenosis in Patients With Heart Failure With Reduced Ejection Fraction

BACKGROUND

Afterload from moderate aortic stenosis (AS) may contribute to adverse outcomes in patients with heart failure with reduced ejection fraction (HFrEF).

OBJECTIVES

The authors evaluated clinical outcomes in patients with HFrEF and moderate AS relative to those without AS and with severe AS.

METHODS

Patients with HFrEF, defined by left ventricular ejection fraction (LVEF) <50% and no, moderate, or severe AS were retrospectively identified. The primary endpoint, defined as a composite of all-cause mortality and heart failure (HF) hospitalization, was compared across groups and within a propensity score-matched cohort.

RESULTS

We included 9,133 patients with HFrEF, of whom 374 and 362 had moderate and severe AS, respectively. Over a median follow-up time of 3.1 years, the primary outcome occurred in 62.7% of patients with moderate AS vs 45.9% with no AS (P < 0.0001); rates were similar with severe and moderate AS (62.0% vs 62.7%; P = 0.68). Patients with severe AS had a lower incidence of HF hospitalization (36.2% vs 43.6%; P < 0.05) and were more likely to undergo AVR within the follow-up period. Within a propensity score-matched cohort, moderate AS was associated with an increased risk of HF hospitalization and mortality (HR: 1.24; 95% CI: 1.04-1.49; P = 0.01) and fewer days alive outside of the hospital (P < 0.0001). Aortic valve replacement (AVR) was associated with improved survival (HR: 0.60; CI: 0.36-0.99; P < 0.05).

CONCLUSIONS

In patients with HFrEF, moderate AS is associated with increased rates of HF hospitalization and mortality. Further investigation is warranted to determine whether AVR in this population improves clinical outcomes.

Incidence and Predictors of New-Onset Atrial Fibrillation After Transcatheter Edge-to-Edge Repair of the Mitral Valve (from the Nationwide Readmissions Database)

Patients who underwent transcatheter edge-to-edge repair (TEER) for mitral regurgitation with atrial fibrillation (AF) at baseline have higher mortality than those without AF. Data on new-onset AF (NOAF) after TEER are limited. Using the 2016 to 2018 Nationwide Readmissions Database, we identified a cohort of patients who underwent TEER and classified them into 3 groups based on AF presence during the study period. The primary end point was the incidence and timing of NOAF up to 6 months after TEER. Logistic regression modeling identified independent predictors of NOAF at readmission. Of the 6,861patients that underwent TEER, 4,134 (59.9%) had AF at baseline, and 239 (3.5%) developed NOAF. Median time-to-NOAF admission was 47 days (interquartile range 16 to 113), and 37% of patients with NOAF presented within 30 days after TEER. Patients with NOAF experienced costlier and longer index-TEER hospitalization and had more co-morbidities. Chronic kidney disease (odds ratio [OR] 1.51, 95% confidence interval [CI] 1.03 to 2.20), fluid and electrolyte disorders (OR 1.59, 95% CI 1.01 to 2.52), and heart failure (OR 1.86, 95% CI 1.01 to 3.44) were identified as independent predictors of NOAF. Hypertensive complications and heart failure were the leading causes of readmission. In conclusion, those patients that developed NOAF after TEER tended to be an overall sicker group at baseline compared with the remainder of the study cohort. These data, obtained from a nationally representative cohort, highlight a particular group of patients subject to developing NOAF and their association with increased rehospitalization in the post-TEER setting. Predictors of NOAF can be screened for during TEER workup to identify patients at increased risk.

Association Between Early Left Ventricular Ejection Fraction Improvement After Transcatheter Aortic Valve Replacement and 5-Year Clinical Outcomes

Importance

In patients with severe aortic stenosis and left ventricular ejection fraction (LVEF) less than 50%, early LVEF improvement after transcatheter aortic valve replacement (TAVR) is associated with improved 1-year mortality; however, its association with long-term clinical outcomes is not known.

Objective

To examine the association between early LVEF improvement after TAVR and 5-year outcomes.

Design, Setting, and Participants

This cohort study analyzed patients enrolled in the Placement of Aortic Transcatheter Valves (PARTNER) 1, 2, and S3 trials and registries between July 2007 and April 2015. High- and intermediate-risk patients with baseline LVEF less than 50% who underwent transfemoral TAVR were included in the current study. Data were analyzed from August 2020 to May 2021.

Exposures

Early LVEF improvement, defined as increase of 10 percentage points or more at 30 days and also as a continuous variable (ΔLVEF between baseline and 30 days).

Main Outcomes and Measures

All-cause death at 5 years.

Results

Among 659 included patients with LVEF less than 50%, 468 (71.0%) were male, and the mean (SD) age was 82.4 (7.7) years. LVEF improvement within 30 days following transfemoral TAVR occurred in 216 patients (32.8%) (mean [SD] ΔLVEF, 16.4 [5.7%]). Prior myocardial infarction, diabetes, cancer, higher baseline LVEF, larger left ventricular end-diastolic diameter, and larger aortic valve area were independently associated with lower likelihood of LVEF improvement. Patients with vs without early LVEF improvement after TAVR had lower 5-year all-cause death (102 [50.0%; 95% CI, 43.3-57.1] vs 246 [58.4%; 95% CI, 53.6-63.2]; P = .04) and cardiac death (52 [29.5%; 95% CI, 23.2-37.1] vs 135 [38.1%; 95% CI, 33.1-43.6]; P = .05). In multivariable analyses, early improvement in LVEF (modeled as a continuous variable) was associated with lower 5-year all-cause death (adjusted hazard ratio per 5% increase in LVEF, 0.94 [95% CI, 0.88-1.00]; P = .04) and cardiac death (adjusted hazard ratio per 5% increase in LVEF, 0.90 [95% CI, 0.82-0.98]; P = .02) after TAVR. Restricted cubic spline analysis demonstrated a visual inflection point at ΔLVEF of 10% beyond which there was a steep decline in all-cause mortality with increasing degree of LVEF improvement. There were no statistically significant differences in rehospitalization, New York Heart Association functional class, or Kansas City Cardiomyopathy Questionnaire Overall Summary score at 5 years in patients with vs without early LVEF improvement. In subgroup analysis, the association between early LVEF improvement and 5-year all-cause death was consistent regardless of the presence or absence of coronary artery disease or prior myocardial infarction.

Conclusions and Relevance

In patients with severe aortic stenosis and LVEF less than 50%, 1 in 3 experience LVEF improvement within 1 month after TAVR. Early LVEF improvement is associated with lower 5-year all-cause and cardiac death.

Patient- and Process-Related Contributors to the Underuse of Aortic Valve Replacement and Subsequent Mortality in Ambulatory Patients With Severe Aortic Stenosis

Background

Many patients with severe aortic stenosis (AS) and an indication for aortic valve replacement (AVR) do not undergo treatment. The reasons for this have not been well studied in the transcatheter AVR era. We sought to determine how patient‐ and process‐specific factors affected AVR use in patients with severe AS.

Methods and Results

We identified ambulatory patients from 2016 to 2018 demonstrating severe AS, defined by aortic valve area ≤1.0 cm². Propensity scoring analysis with inverse probability of treatment weighting was used to evaluate associations between predictors and the odds of undergoing AVR at 365 days and subsequent mortality at 730 days. Of 324 patients with an indication for AVR (79.3±9.7 years, 57.4% men), 140 patients (43.2%) did not undergo AVR. The odds of AVR were reduced in patients aged >90 years (odds ratio [OR], 0.24 [95% CI, 0.08–0.69]; P=0.01), greater comorbid conditions (OR, 0.88 per 1‐point increase in Combined Comorbidity Index [95% CI, 0.79–0.97]; P=0.01), low‐flow, low‐gradient AS with preserved left ventricular ejection fraction (OR, 0.11 [95% CI, 0.06–0.21]), and low‐gradient AS with reduced left ventricular ejection fraction (OR, 0.18 [95% CI, 0.08–0.40]) and were increased if the transthoracic echocardiogram ordering provider was a cardiologist (OR, 2.46 [95% CI, 1.38–4.38]). Patients who underwent AVR gained an average of 85.8 days of life (95% CI, 40.9–130.6) at 730 days.

Conclusions

The proportion of ambulatory patients with severe AS and an indication for AVR who do not receive AVR remains significant. Efforts are needed to maximize the recognition of severe AS, especially low‐gradient subtypes, and to encourage patient referral to multidisciplinary heart valve teams.

Transfemoral Tricuspid Valve Replacement in Patients With Tricuspid Regurgitation: TRISCEND Study 30-Day Results

OBJECTIVES

The TRISCEND study (Edwards EVOQUE Tricuspid Valve Replacement: Investigation of Safety and Clinical Efficacy after Replacement of Tricuspid Valve with Transcatheter Device) is evaluating the safety and performance of transfemoral transcatheter tricuspid valve replacement in patients with clinically significant tricuspid regurgitation (TR) and elevated surgical risk.

BACKGROUND

Transcatheter valve replacement could lead to a paradigm shift in treating TR and improving patient quality of life.

METHODS

In the prospective, single-arm, multicenter TRISCEND study, patients with symptomatic moderate or greater TR, despite medical therapy, underwent percutaneous transcatheter tricuspid valve replacement with the EVOQUE system. A composite rate of major adverse events, echocardiographic parameters, and clinical, functional, and quality-of-life measures were assessed at 30 days.

RESULTS

Fifty-six patients (mean age of 79.3 years, 76.8% female, 91.1% TR severe or greater, 91.1% atrial fibrillation, and 87.5% New York Heart Association functional class III or IV) were treated. At 30 days, TR was reduced to mild or less in 98%. The composite major adverse events rate was 26.8% at 30 days caused by 1 cardiovascular death in a patient with a failed procedure, 2 reinterventions after device embolization, 1 major access site or vascular complication, and 15 severe bleeds, of which none were life-threatening or fatal. No myocardial infarction, stroke, renal failure, major cardiac structural complications, or device-related pulmonary embolism were observed. New York Heart Association significantly improved to functional class I or II (78.8%; P < 0.001), 6-minute walk distance improved 49.8 m (P < 0.001), and Kansas City Cardiomyopathy Questionnaire score improved 19 points (P < 0.001).

CONCLUSIONS

Early experience with the transfemoral EVOQUE system in patients with clinically significant TR demonstrated technical feasibility, acceptable safety, TR reduction, and symptomatic improvement at 30 days. The TRISCEND II randomized trial (NCT04482062) is underway.

Trends in Utilization of Aortic Valve Replacement for Severe Aortic Stenosis

BACKGROUND

Despite the rapid growth of aortic valve replacement (AVR) for aortic stenosis (AS), limited data suggest symptomatic severe AS remains undertreated.

OBJECTIVES

This study sought to investigate temporal trends in AVR utilization among patients with a clinical indication for AVR.

METHODS

Patients with severe AS (aortic valve area <1 cm²) on transthoracic echocardiograms from 2000 to 2017 at 2 large academic medical centers were classified based on clinical guideline indications for AVR and divided into 4 AS subgroups: high gradient with normal left ventricular ejection fraction (LVEF) (HG-NEF), high gradient with low LVEF (HG-LEF), low gradient with normal LVEF (LG-NEF), and low gradient with low LVEF (LG-LEF). Utilization of AVR was examined and predictors identified.

RESULTS

Of 10,795 patients, 6,150 (57%) had an indication or potential indication for AVR, of whom 2,977 (48%) received AVR. The frequency of AVR varied by AS subtype with LG groups less likely to receive an AVR (HG-NEF: 70%, HG-LEF: 53%, LG-NEF: 32%, LG-LEF: 38%, P < 0.001). AVR volumes grew over the 18-year study period but were paralleled by comparable growth in the number of patients with an indication for AVR. In patients with a Class I indication, younger age, coronary artery disease, smoking history, higher hematocrit, outpatient index transthoracic echocardiogram, and LVEF ≥0.5 were independently associated with an increased likelihood of receiving an AVR. AVR was associated with improved survival in each AS-subgroup.

CONCLUSIONS

Over an 18-year period, the proportion of patients with an indication for AVR who did not receive AVR has remained substantial despite the rapid growth of AVR volumes.

Relation of Subacute Kidney Injury to Mortality After Transcatheter Aortic Valve Implantation

Acute kidney injury after transcatheter aortic valve implantation (TAVI) has been associated with adverse outcomes; however, data are limited on the subacute changes in renal function that occur after discharge and their impact on clinical outcomes. This study investigates the relation between subacute changes in kidney function at 30 days after TAVI and survival. Patients from 2 centers who underwent TAVI and survived beyond 30 days with baseline, in-hospital, and 30-day measures of renal function were retrospectively analyzed. Patients were stratified based on change in estimated glomerular filtration rate (eGFR) from baseline to 30 days as follows: improved (≥15% higher than baseline), worsened (≤15% lower), or unchanged (values in between). Univariable and multivariable models were constructed to identify predictors of subacute changes in renal function and of 2-year mortality. Of the 492 patients who met inclusion criteria, eGFR worsened in 102 (22%), improved in 110 (22%), and was unchanged in 280 (56%). AKI occurred in 90 patients (18%) and in only 27% of patients with worsened eGFR at 30 days. After statistical adjustment, worsened eGFR at 30 days (hazard ratio vs unchanged eGFR 2.09, 95% CI 1.37 to 3.19, p <0.001) was associated with worse survival, whereas improvement in renal function was not associated with survival (hazard ratio vs unchanged eGFR 1.30, 95% CI 0.79 to 2.11, p = 0.30). Worsened renal function at 30 days after TAVI is associated with increased mortality after TAVI. In conclusion, monitoring renal function after discharge may identify patients at high risk of adverse outcomes.

Efficacy and safety of percutaneous patent foramen ovale closure in patients with a hypercoagulable disorder

BACKGROUND

Transcatheter closure of patent foramen ovale (PFO) in patients with cryptogenic stroke reduces the rate of recurrent events. Although presence of thrombophilia increases the risk for paradoxical emboli through a PFO, such patients were excluded from large randomized trials.

OBJECTIVES

We compared the safety and efficacy of percutaneous PFO closure in patients with and without a hypercoagulable state.

METHODS

Data from 800 consecutive patients undergoing percutaneous PFO closure in our medical center were analyzed. All patients were independently evaluated by specialists in neurology, cardiology, hematology, and vascular medicine. A post-procedural treatment of at least 3 months of anticoagulation was utilized in patients with thrombophilia. Follow-up events included death, recurrent neurological events, and the need for reintervention for significant residual shunt.

RESULTS

A hypercoagulable state was found in 239 patients (29.9%). At median follow-up of 41.9 months, there were no differences in the frequencies of stroke or transient ischemic attack between patients with or without thrombophilia (2.5% in non-hypercoagulable group vs. 3.4% in hypercoagulable group, log-rank test p = 0.35). There were no significant differences in baseline demographics, echocardiographic characteristics, procedural success, or complications between groups.

CONCLUSION

Percutaneous PFO closure is a safe and effective therapeutic approach for patients with cryptogenic stroke and an underlying hypercoagulable state.

Validation study to determine the accuracy of central blood pressure measurement using the SphygmoCor XCEL cuff device in patients with severe aortic stenosis undergoing transcatheter aortic valve replacement

Central aortic blood pressure could be helpful in the evaluation of patients with aortic stenosis (AS). The SphygmoCor XCEL device estimates central blood pressure (BP) measurement with its easy‐to‐use, operator‐independent procedure. However, this device has not been properly validated against invasive measurement in patients with severe AS. We evaluated the relationship between cuff‐brachial BP, transfer function‐estimated and invasively measured central aortic pressure in patients with severe AS before and after transcatheter aortic valve replacement (TAVR). Agreement between techniques was analyzed and, according to the ARTERY Society recommendations, the minimum acceptable error was a mean difference ± SD ≤5 ± ≤8 mm Hg. A total of 94 patients with AS undergoing TAVR had simultaneous non‐invasive and invasive measurements of central BP before and after the procedure. Before TAVR central systolic BP was in average slightly underestimated, though with wide variability, when using the default calibration of brachial‐cuff SBP (mean difference ± SD, −3 ± 15 mm Hg), and after TAVR the degree of underestimation increased (mean difference ± SD, −9 ± 13 mm Hg). The agreement tended to improve for those patients with low aortic gradient stenosis compared to those with high gradient at baseline (mean difference ± SD, −2 ± 11 mm Hg vs. −4 ± 17, respectively, p = .3). The cuff‐brachial systolic BP yielded numerically lower degree of agreement and weaker correlation with invasive measurements than SphygmoCor XCEL. In patients with severe AS the SphygmoCor XCEL cuff device, despite showing strong correlation, does not meet the ARTERY Society accuracy criteria for non‐invasive measurement of central SBP.

Association between hospital cardiovascular procedural volumes and transcatheter mitral valve repair outcomes

BACKGROUND

Cardiovascular procedural volumes can serve as metrics of hospital infrastructure and quality, and are the basis for thresholds for initiating transcatheter mitral valve repair (TMVr) programs. Whether hospital volumes of TMVr, surgical mitral valve replacement or repair (SMVRr), and percutaneous coronary intervention (PCI) are indicators of TMVr quality of care is not known.

METHODS

We used the 2017 Nationwide Readmissions Database to identify hospitals that performed at least 5 TMVr procedures. Hospitals were divided into quartiles of TMVr volume. Associations of hospital TMVr, SMVRr, and PCI volumes, as well as SMVRr and PCI outcomes with TMVr outcomes were examined. Outcomes studied were risk-standardized in-hospital mortality rate (RSMR) and 30-day readmission rate (RSRR).

RESULTS

The study included 3404 TMVr procedures performed across 150 hospitals in the US. The median hospital TMVr volume was 17 (IQR 10, 28). The mean hospital-level RSMR and RSRR for TMVr were 3.0% (95% CI 2.5%, 3.4%) and 14.8% (95% CI 14.5%, 15.0%), respectively. There was no significant association between hospital TMVr volume (as quartiles or as a continuous variable) and TMVr RSMR or RSRR (P > 0.05). Similarly, there was weak or no correlation between hospital SMVRr and PCI volumes and outcomes with TMVr RSMR or RSRR (Pearson correlation coefficients, r = -0.199 to 0.269).

CONCLUSION

In this study, we found no relationship between hospital TMVr, SMVRr, and PCI volume and TMVr outcomes. Further studies are needed to determine more appropriate structure and process measures to assess the performance of established and new TMVr centers.

Prospective Evaluation of Transseptal TMVR for Failed Surgical Bioprostheses: MITRAL Trial Valve-in-Valve Arm 1-Year Outcomes

OBJECTIVES

The aim of this study was to assess 1-year clinical outcomes among high-risk patients with failed surgical mitral bioprostheses who underwent transseptal mitral valve-in-valve (MViV) with the SAPIEN 3 aortic transcatheter heart valve (THV) in the MITRAL (Mitral Implantation of Transcatheter Valves) trial.

BACKGROUND

The MITRAL trial is the first prospective study evaluating transseptal MViV with the SAPIEN 3 aortic THV in high-risk patients with failed surgical mitral bioprostheses.

METHODS

High-risk patients with symptomatic moderate to severe or severe mitral regurgitation (MR) or severe mitral stenosis due to failed surgical mitral bioprostheses were prospectively enrolled. The primary safety endpoint was technical success. The primary THV performance endpoint was absence of MR grade ≥2+ or mean mitral valve gradient ≥10 mm Hg (30 days and 1 year). Secondary endpoints included procedural success and all-cause mortality (30 days and 1 year).

RESULTS

Thirty patients were enrolled between July 2016 and October 2017 (median age 77.5 years [interquartile range (IQR): 70.3 to 82.8 years], 63.3% women, median Society of Thoracic Surgeons score 9.4% [IQR: 5.8% to 12.0%], 80% in New York Heart Association functional class III or IV). The technical success rate was 100%. The primary performance endpoint in survivors was achieved in 96.6% (28 of 29) at 30 days and 82.8% (24 of 29) at 1 year. Thirty-day all-cause mortality was 3.3% and was unchanged at 1 year. The only death was due to airway obstruction after swallowing several pills simultaneously 29 days post-MViV. At 1-year follow-up, 89.3% of patients were in New York Heart Association functional class I or II, the median mean mitral valve gradient was 6.6 mm Hg (interquartile range: 5.5 to 8.9 mm Hg), and all patients had MR grade ≤1+.

CONCLUSIONS

Transseptal MViV in high-risk patients was associated with 100% technical success, low procedural complication rates, and very low mortality at 1 year. The vast majority of patients experienced significant symptom alleviation, and THV performance remained stable at 1 year.

Association of Pulmonary Hypertension With Clinical Outcomes of Transcatheter Mitral Valve Repair

Importance

Pulmonary hypertension (pHTN) is associated with increased risk of mortality after mitral valve surgery for mitral regurgitation. However, its association with clinical outcomes in patients undergoing transcatheter mitral valve repair (TMVr) with a commercially available system (MitraClip) is unknown.

Objective

To assess the association of pHTN with readmissions for heart failure and 1-year all-cause mortality after TMVr.

Design, Setting, and Participants

This retrospective cohort study analyzed 4071 patients who underwent TMVr with the MitraClip system from November 4, 2013, through March 31, 2017, across 232 US sites in the Society of Thoracic Surgery/American College of Cardiology Transcatheter Valve Therapy registry. Patients were stratified into the following 4 groups based on invasive mean pulmonary arterial pressure (mPAP): 1103 with no pHTN (mPAP, <25 mm Hg [group 1]); 1399 with mild pHTN (mPAP, 25-34 mm Hg [group 2]); 1011 with moderate pHTN (mPAP, 35-44 mm Hg [group 3]); and 558 with severe pHTN (mPAP, ≥45 mm Hg [group 4]). Data were analyzed from November 4, 2013, through March 31, 2017.

Interventions

Patients were stratified into groups before TMVr, and clinical outcomes were assessed at 1 year after intervention.

Main Outcomes and Measures

Primary end point was a composite of 1-year mortality and readmissions for heart failure. Secondary end points were 30-day and 1-year mortality and readmissions for heart failure. Linkage to Centers for Medicare & Medicaid Services administrative claims was performed to assess 1-year outcomes in 2381 patients.

Results

Among the 4071 patients included in the analysis, the median age was 81 years (interquartile range, 73-86 years); 1885 (46.3%) were women and 2186 (53.7%) were men. The composite rate of 1-year mortality and readmissions for heart failure was 33.6% (95% CI, 31.6%-35.7%), which was higher in those with pHTN (27.8% [95% CI, 24.2%-31.5%] in group 1, 32.4% [95% CI, 29.0%-35.8%] in group 2, 36.0% [95% CI, 31.8%-40.2%] in group 3, and 45.2% [95% CI, 39.1%-51.0%] in group 4; P < .001). Similarly, 1-year mortality (16.3% [95% CI, 13.4%-19.5%] in group 1, 19.8% [95% CI, 17.0%-22.8%] in group 2, 22.4% [95% CI, 18.8%-26.1%] in group 3, and 27.8% [95% CI, 22.6%-33.3%] in group 4; P < .001) increased across pHTN groups. The association of pHTN with mortality persisted despite multivariable adjustment (hazard ratio per 5-mm Hg mPAP increase, 1.05; 95% CI, 1.01-1.09; P = .02).

Conclusions and Relevance

These findings suggest that pHTN is associated with increased mortality and readmission for heart failure in patients undergoing TMVr using the MitraClip system for severe mitral regurgitation. Further efforts are needed to determine whether earlier intervention before pHTN develops will improve clinical outcomes.

Efficacy and safety of percutaneous patent foramen ovale closure in patients with a hypercoagulable disorder

Background

Transcatheter closure of patent foramen ovale (PFO) in patients with cryptogenic stroke reduce the rate of recurrent events. Although presence of thrombophilia increases the risk for paradoxical emboli through a PFO, such patients were excluded from the large randomized studies.

Purpose

To examine the effect of hypercoagulable state on clinical outcomes after PFO closure.

Methods

We retrospectively analyzed data of 800 consecutive patients undergoing percutaneous PFO closure at the Massachusetts general hospital. We compared the safety and efficacy of the procedure in patients with and without a hypercoagulable state. Periprocedural treatment included 3 months of anticoagulation followed by low dose aspirin.

Results

A hypercoagulable disorder was found in 239 patients (29.9%). There were no significant differences in baseline demographics, echocardiographic characteristics, procedural success rate, or complication rate between both groups. At median follow-up of 41.9 months there were no differences in the rate of stroke/transient ischemic attack (2.5% in non-hypercoagulable group vs. 3.4% in hypercoagulable group, log-rank test p=0.349). Survival analysis of composite outcome that included: ischemic neurologic event, reintervention and procedural or neurologic death did not show significant difference between groups (Log-rank p=0.122).

Conclusion

Percutaneous PFO closure is a safe and effective therapeutic approach for patients with cryptogenic stroke and an underlying hypercoagulable state

Funding Acknowledgement

Type of funding source: Public hospital(s). Main funding source(s): Research funds of the Massachusetts general hospital

Ventricular stroke work and vascular impedance refine the characterization of patients with aortic stenosis

Aortic stenosis (AS) management is classically guided by symptoms and valvular metrics. However, the natural history of AS is dictated by coupling of the left ventricle, aortic valve, and vascular system. We investigated whether metrics of ventricular and vascular state add to the appreciation of AS state above valve gradient alone. Seventy patients with severe symptomatic AS were prospectively followed from baseline to 30 days after transcatheter aortic valve replacement (TAVR). Quality of life (QOL) was assessed using the Kansas City Cardiomyopathy Questionnaire. Left ventricular stroke work (SW_LV) and vascular impedance spectrums were calculated noninvasively using in-house models based on central blood pressure waveforms, along with hemodynamic parameters from echocardiograms. Patients with higher preprocedural SW_LV and lower vascular impedance were more likely to experience improved QOL after TAVR. Patients fell into two categories: those who did and those who did not exhibit increase in blood pressure after TAVR. In patients who developed hypertension (19%), vascular impedance increased and SW_LV remained unchanged (impedance at zeroth harmonic: Z ₀, from 3964.4 to 4851.8 dyne·s/cm³, P = 0.039; characteristic impedance: Z _c, from 376.2 to 603.2 dyne·s/cm³, P = 0.033). SW_LV dropped only in patients who did not develop new hypertension after TAVR (from 1.58 to 1.26 J; P < 0.001). Reduction in valvular pressure gradient after TAVR did not predict change in SW_LV (r = 0.213; P = 0.129). Reduction of SW_LV after TAVR may be an important metric in management of AS, rather than relying solely on the elimination of transvalvular pressure gradients.

Temporal Trends in Prevalence of Tricuspid Valve Disease in Hospitalized Patients in the United States

Tricuspid valve disease (TVD), particularly tricuspid regurgitation, is a common valvular pathology that is associated with increased morbidity and mortality. The prevalence of TVD in hospitalized patients has not been well characterized. We used the National Inpatient Sample to determine the overall and age- and sex-specific prevalence and temporal trends in prevalence of TVD in hospitalized patients in the US. All-cause and heart failure (HF) hospitalizations in patients ≥50 years of age from January 2006 to September 2015 in the US were identified. Temporal trends in the prevalence of TVD were studied using Poisson regression. Of 194,184,433 all-cause and 38,083,773 HF hospitalizations in patients ≥50 years of age, 3,235,292 (1.7%) and 1,787,548 (4.7%) had a diagnosis of TVD, respectively. From 2006 to 2015, the prevalence of TVD in all hospitalizations and in HF hospitalizations increased from 1.7% to 2.0% and from 3.9% to 5.7%, respectively (p_trend <0.001 for both), particularly in those ≥85 years of age and in women. In patients with TVD, primary reasons for hospitalizations were HF (20.8%), infections (10.1%), arrhythmias (9.8%), respiratory conditions (8.4%), and coronary artery disease/acute myocardial infarction (8.2%). In-hospital mortality and length of stay in patients with TVD remained unchanged, whereas costs of hospitalization increased during the study period. In conclusion, the prevalence of TVD in all hospitalized patients and in those hospitalized with HF has increased over the past several years, particularly in those ≥85 years of age and in women. Approximately 1 in 5 hospitalizations with a diagnosis of TVD is due to HF.

Managing Severe Aortic Stenosis in the COVID-19 Era

The novel coronavirus disease-2019 (COVID-19) pandemic has created uncertainty in the management of patients with severe aortic stenosis. This population experiences high mortality from delays in treatment of valve disease but is largely overlapping with the population of highest mortality from COVID-19. The authors present strategies for managing patients with severe aortic stenosis in the COVID-19 era. The authors suggest transitions to virtual assessments and consultation, careful pruning and planning of necessary testing, and fewer and shorter hospital admissions. These strategies center on minimizing patient exposure to COVID-19 and expenditure of human and health care resources without significant sacrifice to patient outcomes during this public health emergency. Areas of innovation to improve care during this time include increased use of wearable and remote devices to assess patient performance and vital signs, devices for facile cardiac assessment, and widespread use of clinical protocols for expedient discharge with virtual physical therapy and cardiac rehabilitation options.

Perforating the GORE® CARDIOFORM septal occluder and atrial septal defect occluder to gain access to the left atrium

OBJECTIVE

Perforate the expanded polytetrafluoroethylene membrane of the GORE® CARDIOFORM Septal Occluder (GSO) and GORE® CARDIOFORM ASD Occluder (GCA) after implantation.

BACKGROUND

Percutaneous transseptal access to the left atrium is necessary for many structural and electrophysiological procedures. The potential need to access the left atrium may influence decision-making for patent foramen ovale or atrial septal defect closure.

METHODS

Sixteen canines underwent implantation of equal number GSO or GCA devices. A transseptal crossing procedure was performed through the device 85 (±1) days postoccluder implantation. The crossing procedure was performed utilizing commercially available equipment: radiofrequency/SureFlex sheath and standard needle/Mullin's sheath. Progressive dilation of the perforation was performed to allow passage of a 12 French Mullin's sheath into the left atrium.

RESULTS

Left atrial access was achieved in all cases. Postmortem analysis demonstrated passage through both occluder discs in all radiofrequency/SureFlex sheath cases (4 GSO, 4 GCA) and half of the standard needle/Mullin's sheath cases (3 GSO, 1 GCA). The remaining standard needle/Mullin's sheath cases demonstrated perforation through the right atrial disc but passage around the septal aspect of the left atrial disc, thus not perforating the left atrial disc. No acute embolic complications from the procedure were observed.

CONCLUSIONS

Left atrial access may be achieved through the GSO or GCA devices after implantation and endothelialization. The combination of a radiofrequency needle and steerable sheath provides benefit over a standard needle and Mullin's sheath in accomplishing passage through both occluder discs.

Thirty-day readmissions after transcatheter versus surgical mitral valve repair in high-risk patients with mitral regurgitation: Analysis of the 2014-2015 Nationwide readmissions databases

OBJECTIVE

Determine the rates, reasons, predictors, and costs of 30-day readmissions following transcatheter mitral valve repair (TMVR) versus surgical mitral valve repair (SMVR) in the United States.

BACKGROUND

Data on 30-day readmissions after TMVR are limited.

METHODS

High-risk patients with mitral regurgitation (MR) undergoing TMVR or SMVR were identified from the 2014-2015 Nationwide Readmissions Databases. Multivariable stepwise regression models were used to identify independent predictors of 30-day readmission. Risk of 30-day readmission was compared between the two groups using univariate and propensity score adjusted regression models.

RESULTS

Among 8,912 patients undergoing mitral valve repair during 2014-2015 (national estimate 17,809), we identified 7,510 (84.7%) that underwent SMVR and 1,402 (15.3%) that underwent TMVR. Thirty-day readmission rates after SMVR and TMVR were 10.7% and 11.7%, respectively (unadjusted OR 1.11, 95% CI 0.89-1.39, p = .35). After propensity score adjustment, TMVR was associated with a lower risk of 30-day readmissions compared with SMVR (adjusted OR 0.70, 95% CI 0.51-0.95, p = .02). Heart failure and arrhythmias were the leading cardiac reasons for readmission. Anemia and fluid and electrolyte disorder were independent predictors of 30-day readmission after TMVR. Demographics, comorbidities, and length of stay were independent predictors of 30-day readmission after SMVR.

CONCLUSIONS

One in 10 patients are readmitted within 30 days following TMVR or SMVR. Approximately half of the readmissions are for cardiac reasons. The predictors of 30-day readmission are different among patients undergoing TMVR and SMVR, but can be easily screened for to identify patients at highest risk for readmission.

Transcatheter Versus Surgical Aortic Valve Replacement in Patients With Prior Coronary Artery Bypass Grafting: Trends in Utilization and Propensity-Matched Analysis of In-Hospital Outcomes

BACKGROUND

A significant proportion of patients requiring aortic valve replacement (AVR) have undergone prior coronary artery bypass grafting (CABG). Reoperative heart surgery is associated with increased risk. Data on relative utilization and comparative outcomes of transcatheter (TAVR) versus surgical AVR (SAVR) in patients with prior CABG are limited.

METHODS AND RESULTS

We queried the 2012 to 2014 National Inpatient Sample databases to identify isolated AVR hospitalizations in adults with prior CABG. In-hospital outcomes of TAVR versus SAVR were compared using propensity-matched analysis. Of 147 395 AVRs, 15 055 (10.2%) were in patients with prior CABG. The number of TAVRs in patients with prior CABG increased from 1615 in 2012 to 4400 in 2014, whereas the number of SAVRs decreased from 2285 to 1895 (P_trend<0.001). There were 3880 records in each group in the matched cohort. Compared with SAVR, TAVR was associated with similar in-hospital mortality (2.3% versus 2.4%; P=0.71) but lower incidence of myocardial infarction (1.5% versus 3.4%; P<0.001), stroke (1.4% versus 2.7%; P<0.001), bleeding complications (10.6% versus 24.6%; P<0.001), and acute kidney injury (16.2% versus 19.3%; P<0.001). Requirement for prior permanent pacemaker was higher in the TAVR cohort, whereas the incidence of vascular complications and acute kidney injury requiring dialysis was similar in the 2 groups. Average length of stay was shorter in patients undergoing TAVR.

CONCLUSIONS

TAVR is being increasingly used as the preferred modality of AVR in patients with prior CABG. Compared with SAVR, TAVR is associated with similar in-hospital mortality but lower rates of in-hospital complications in this important subset of patients.

Abstract WP401: Residual Shunting Post PFO Closure is Associated With Increased Long-term Risk of Recurrent Stroke

Background: Patent foramen ovale (PFO) is an independent risk factor for ischemic stroke, and recent clinical trials have shown long-term benefit of PFO closure. We previously found PFO may increase the risk of stroke due to right-to-left shunting, resulting in venous contamination of arterial circulation, with elevated neurovascular mediators such as homocysteine. However, in clinical practice, residual blood shunting can be observed in ~10% of patients post PFO closure, with unclear significance. Here we prospectively investigated the long-term influence of residual shunting on patient outcome.

Method: 1018 PFO stroke patients s/p PFO closure from several medical centers were prospectively recruited in accordance with IRB protocol and followed up to 7 years.

Result: While closure rate at our center is much lower (<5%), overall closure rate of patients from all major referral centers range between 5-14%. Patients with compete PFO closure (86%) developed higher event-free probability from recurrent TIA/stroke compared to those with residual shunting (14%) (Figure1A, p = 0.001). The risk of recurrent stroke depended on residual shunt size with lower event-free probability in larger shunting (Figure 1B, p = 0.002).

Conclusion: Consistent with clinical trials, our prospective observational study suggests complete PFO closure results in lower risk of stroke recurrence. Patients with residual shunting (incomplete PFO closure) may face continued risk, though the overall risk of stroke recurrence is very low. PFO-related shunting appears to be critical in the pathophysiology of recurrent stroke.

Abstract TP160: May-Thurner Syndrome is Associated With Stroke Due to Paradoxical Embolism

Background: May-Thurner Syndrome (MTS) is a potential risk factor for cryptogenic stroke (CS). While retrospective reports have found important association with MTS in CS, prospective data has been lacking. In this study, we prospectively explored the epidemiology and clinical correlates of MTS patients with cryptogenic stroke.

Method: Eligible patients were prospectively recruited in accordance with an IRB-approved protocol. All patients underwent full evaluation of etiopathogenesis of stroke such as MRI/MRA, long-term cardiac telemetry (>30 days), echocardiography, and extensive thrombophilia screen (AT3, FV Leiden, Proteins C and S; prothrombin gene mutations, APLAbs, lipoprotein(a), homocysteine) and 1.5T pelvic MRV.

Results: We prospectively recruited 1,131 acute ischemic stroke patients, with 59 patients with PFO-related CS; 15 (40.5%) had May-Thurner anatomy (MTA), and 6 (16.2%) had MTS. MTS pts are younger (36.33±9.95 vs. 53.35±14.78, p=0.011), with a lower trend for BMI (24.40±4.87 V.S. 31.13±8.75, p=0.051, table 1). Lower BMI is predictive of MTS in CS (<=22) with high specificity 93.3% (AUC=0.756, p=0.007).

Conclusion: In this prospective study, we found MTA and MTS to be very common in PFO CS patients - especially in younger patients with lower BMI and without traditional stroke risk factors. MTS is a novel risk factor that may aide in the diagnosis of PFO CS, and needs further study.

Outcomes of hemodynamic support with Impella in very high-risk patients undergoing balloon aortic valvuloplasty: Results from the Global cVAD Registry

BACKGROUND

Reports on the role of hemodynamic support devices in patients with severe aortic stenosis (AS) and left ventricular (LV) dysfunction undergoing balloon aortic valvuloplasty (BAV) are limited.

METHODS

Patients were identified from the cVAD registry, an ongoing multicenter voluntary registry at selected sites in North America that have used Impella in >10 patients.

RESULTS

A total of 116 patients with AS who underwent BAV with Impella support were identified. Mean age was 80.41±9.03years and most patients were male. Mean STS score was 18.77%±18.32, LVEF was 27.14%±16.07, and 42% underwent concomitant PCI. In most cases Impella was placed electively prior to BAV, whereas 26.7% were placed as an emergency. The two groups had similar baseline characteristics except for higher prevalence of CAD and lower LVEF in the elective group, and higher STS score in the emergency group. Elective strategy was associated higher 1-year survival compared to emergency placement (56% vs. 29.2%, p=0.003). One-year survival was higher when BAV was used as a bridge to definitive therapy as opposed to palliative treatment (90% vs. 28%, p<0.001). On multivariate analysis, STS score and aim of BAV (bridge to definitive therapy vs. palliative indication) were independent predictors of mortality.

CONCLUSION

In this large cohort of patients with AS and severe LV dysfunction undergoing BAV, our results demonstrates feasibility and promising long-term outcomes using elective Impella support with the intention to bridge to a definitive therapy.

Metabolite Profiles Predict Acute Kidney Injury and Mortality in Patients Undergoing Transcatheter Aortic Valve Replacement

Background

Acute kidney injury (AKI) occurs commonly after transcatheter aortic valve replacement (TAVR) and is associated with markedly increased postoperative mortality. We previously identified plasma metabolites predictive of incident chronic kidney disease, but whether metabolite profiles can identify those at risk of AKI is unknown.

Methods and Results

We performed liquid chromatography–mass spectrometry–based metabolite profiling on plasma from patients undergoing TAVR and subjects from the community‐based Framingham Heart Study (N=2164). AKI was defined by using the Valve Academic Research Consortium‐2 criteria. Of 44 patients (mean age 82±9 years, 52% female) undergoing TAVR, 22 (50%) had chronic kidney disease and 9 (20%) developed AKI. Of 85 metabolites profiled, we detected markedly concordant cross‐sectional metabolic changes associated with chronic kidney disease in the hospital‐based TAVR and Framingham Heart Study cohorts. Baseline levels of 5‐adenosylhomocysteine predicted AKI after TAVR, despite adjustment for baseline glomerular filtration rate (odds ratio per 1‐SD increase 5.97, 95% CI 1.62–22.0; P=0.007). Of the patients who had AKI, 6 (66.7%) subsequently died, compared with 3 (8.6%) deaths among those patients who did not develop AKI (P=0.0008) over a median follow‐up of 7.8 months. 5‐adenosylhomocysteine was predictive of all‐cause mortality after TAVR (hazard ratio per 1‐SD increase 2.96, 95% CI 1.33–6.58; P=0.008), independent of baseline glomerular filtration rate.

Conclusions

In an elderly population with severe aortic stenosis undergoing TAVR, metabolite profiling improves the prediction of AKI. Given the multifactorial nature of AKI after TAVR, metabolite profiles may identify those patients with reduced renal reserve.

MP6: HOMOCYSTEINE LEVEL IN PFO RELATED STROKE PATIENTS WITH RESPECT TO MEDICAL THERAPY VS PFO CLOSURE

Purpose of Study

Homocysteine is an independent risk factor of ischemic stroke by promoting vascular endothelial dysfunction and thrombotic process through oxidative stress. We previously found that PFO closure may reduce total homocysteine level (tHcy) in plasma. Here, we compare the effect of PFO closure and medical treatment in reducing mild homocysteinemia in PFO-related stroke patients.

Methods Used

28 PFO-related stroke patients with mildly elevated tHcy (>12 µmol/l) were prospectively recruited in accordance with IRB. 14 received PFO closure and 14 were treated by medical therapy (antiplatelet/anticoagulant) alone. None of the patients were on folate or vitamin B supplementation. Plasma was collected at baseline and 1 year follow-up after treatment. tHcy level was determined by selected reaction monitoring using mass spectrometry.

Summary of Results

Compared to medical therapy, PFO closure resulted in a lower tHcy level during follow-up (PFO closure: 11.13±3.94 µmol/L, medical therapy: 15.48±3.55 µmol/L, p=0.006), with no difference at baseline (PFO closure: 17.77±4.39 µmol/L, medical therapy: 16.47±7.50 µmol/L, p=0.575). Mild hyperhomocysteinemia patients post PFO closure had a significant reduction of tHcy by 37.34% (p=0.0005), with 71.43% of the patients (10 of 14) having tHcy levels back to normal (<12 µmol/l), while most of medically treated patients (13 of 14) stayed abnormal (p=0.4820) (χ2-test, adjusted p=0.002).

Conclusions

We found that compared with routine medical therapy, PFO closure reduced tHcy level in patients with mild hyperhomocysteinemia. Since PFO stroke patients tend to be younger, the life-time risk of even mildly elevated tHcy may be important for future thrombotic risk. Understanding the mechanism of PFO-related tHcy changes is important in optimizing medical treatment (e.g, folate replacement); studies are ongoing.

Abstract MP6 Figure 1

15: PFO CLOSURE REDUCES PLASMA LEVELS OF SEROTONIN IN A LONG TERM FOLLOWUP OF STROKE PATIENTS

Purpose of Study

PFO allows venous clots and vasoactive factors to bypass pulmonary filtration and remain in circulation. We previously identified an immediate reduction of procoagulant serotonin (5-HT) in left atrial blood post PFO closure. To understand the long-term effect of PFO closure, we report the change of 5-HT in peripheral venous blood in 1-year followup.

Methods Used

97 PFO-related stroke patients were recruited on IRB approval. Venous blood was collected at baseline (BL) and 1 year follow-up (FU) of treatments (PFO closure and medical therapy). Plasma 5-HT was quantified by mass spectrometry. Patients with serotonin modifying medications (ie. SSRIs) or conditions (anxiety/depression) were excluded.

Summary of Results

5-HT level in peripheral venous blood was significantly reduced by 27.27% (BL: 7.57±8.04 µM; FU: 5.51±5.72 µM; p=0.0034) in 61 patients receiving PFO closure (figure 1A). In the 37 PFO patients treated with medicine alone, no changes were observed (BL: 5.79±7.15 µM; FU: 6.25±6.68 µM; p=0.4050) (figure 1B). 5-HT reduction was independently associated with PFO closure after adjusting for age, gender, medical history and medication status in a multivariate regression (figure 1C).

Conclusions

We found that PFO closure independently reduced 5-HT level in peripheral venous blood. These results support the hypothesis that PFO related right-to-left interatrial shunt may foster higher level of procoagulant and vascoactive substances in circulation. While PFO closure decrease prothrombotic markers immediately post closure, this effect is sustained in long term followup up to 1 year. Further studies on the clinical outcome of these PFO patients with respect to their prothrombotic circulatory profiles are ongoing.

Abstract 15 Figure 1

Abstract TP443: Homocysteine Level in PFO Related Stroke Patients With Respect to Medical Therapy vs PFO Closure

Background: Homocysteine is an independent risk factor of ischemic stroke by promoting vascular endothelial dysfunction and thrombotic process through oxidative stress. We previously found that PFO closure may reduce total homocysteine level (tHcy) in plasma. Here, we compare the effect of PFO closure and medical treatment in reducing mild homocysteinemia in PFO-related stroke patients.

Method: 28 PFO-related stroke patients with mildly elevated tHcy (>12 μmol/l) were prospectively recruited in accordance with IRB. 14 received PFO closure and 14 were treated by medical therapy (antiplatelet/anticoagulant) alone. None of the patients were on folate or vitamin B supplementation. Plasma was collected at baseline and 1 year follow-up after treatment. tHcy level was determined by selected reaction monitoring using mass spectrometry.

Result: Compared to medical therapy, PFO closure resulted in a lower tHcy level during follow-up (PFO closure: 11.13 ± 3.94 μmol/L, medical therapy: 15.48 ± 3.55 μmol/L, p = 0.006), with no difference at baseline (PFO closure: 17.77 ± 4.39 μmol/L, medical therapy: 16.47 ± 7.50 μmol/L, p = 0.575). Mild hyperhomocysteinemia patients post PFO closure had a significant reduction of tHcy by 37.34% (p = 0.0005), with 71.43% of the patients (10 of 14) having tHcy levels back to normal (<12 μmol/l), while most of medically treated patients (13 of 14) stayed abnormal (p = 0.4820) (χ2-test, adjusted p = 0.002).

Conclusion: We found that compared with routine medical therapy, PFO closure reduced tHcy level in patients with mild hyperhomocysteinemia. Since PFO stroke patients tend to be younger, the life-time risk of even mildly elevated tHcy may be relevant for future thrombotic risk. Understanding the mechanism of PFO-related tHcy changes is important in optimizing medical treatment (e.g. folate replacement); studies are ongoing.

Abstract TP426: PFO Closure Reduces Plasma Levels of Serotonin in Long Term Follow up of Stroke Patients

Background: PFO allows venous clots and vasoactive circulatory factors to bypass pulmonary filtration and remain in circulation. Serotonin (5-HT) has procoagulant and oxidative roles in both cardiovascular and neurovascular injury. We previously identified an immediate reduction of 5-HT in left atrial blood post PFO closure. To understand the long-term effect of PFO closure, we report the changes of 5-HT in peripheral venous blood in 1-year follow-up.

Method: 97 PFO-related stroke patients were recruited in accordance with IRB. Venous blood was collected at baseline (BL) and 1 year follow-up (FU) post treatment (PFO closure or medical therapy). Plasma 5-HT was quantified by mass spectrometry. Patients with serotonin modifying medications (e.g. SSRIs) or conditions (e.g. anxiety/depression) were excluded.

Result: 5-HT concentration in peripheral venous blood was significantly reduced by 27.27% (BL: 7.57 ± 8.04 μmol/l; FU: 5.51 ± 5.72 μmol/l; p = 0.0034) in 61 patients receiving PFO closure (Fig 1A). In the 37 PFO patients treated with medical therapy alone, no changes were observed (5-HT: BL: 5.79 ± 7.15 μmol/l; FU: 6.25 ± 6.68 μmol/l; p = 0.4050) (Fig 1B). This decrease in serotonin was independently associated with PFO closure after adjusting for age, gender, medical history and medication status in a multivariate regression (Fig 1C).

Conclusion: We found that PFO closure independently reduced 5-HT level in peripheral venous blood. These results support the hypothesis that PFO associated right-to-left interatrial shunting may foster higher levels of procoagulant and vasoactive substances in circulation. We have previously found PFO closure to decrease prothrombotic markers immediately post closure; this effect is now shown also to be sustained in long term follow-up up to 1 year. Further studies are ongoing on the clinical outcome of these PFO related stroke patients with respect to their prothrombotic circulatory profiles.

Percutaneous Mitral Valve Edge-to-Edge Repair for Degenerative Mitral Regurgitation

OPINION STATEMENT

Surgical mitral valve (MV) repair remains the gold standard to treat patients with significant degenerative mitral regurgitation (DMR). Medical therapy was the only option for patients found to be not appropriate for MV surgery until the development of percutaneous/transcatheter MV repair options that now allow to reduce MR less invasively and safely. This article discusses the basic mechanisms of MR and the rationale for MR intervention and offers a detailed review on percutaneous/transcatheter MV repair with the MitraClip.

Abstract W P398: PFO Closure Reduces High Homocysteine Level in Atrial Blood of Stroke Patients

Background: PFO allows venous clots to bypass pulmonary filtration, leading to strokes. We previous found in metabolite screening that PFO endovascular closure lower markers of oxidative stress and homocysteine levels in peripheral venous blood. Here we study changes of homocysteine during endovascular closure in cardiac atrial blood to better understand the central metabolism of PFO in circulation.

Method: PFO stroke patients are propectively recruited according to IRB approval with plasma sampled from left (LA) and right (RA) atria pre- and post- PFO closure (n=97). Total homocysteine (tHCY) level was measured by selected reaction monitoring using mass spectrometry.

Result: tHCY level decreased significantly in both RA and LA post PFO closure (Fig. 1A, p = 0.0014; RA: reduced by 8.54% Fig. 1B, p = 0.0304; LA: reduced by 9.90% Fig. 1C, p = 0.0470). Notably, tHCY reduction was skewed towards patients with higher tHCY levels before PFO closure (Fig. 1D and E, Kolmogorov-Smirnov test, RA: p = 0.0413; LA: p = 0.0010), such that more patients with higher tHCY level had a more significant reduction in tHCY levels compared to those with lower/normal levels.

Conclusion: We found that PFO closure efficiently reduced tHCY level in both venous and arterial systems of stroke patients with high tHCY level. This effect is more pronounced in patients with higher levels suggesting PFO closure may help change the pathophysiology of hyperhomocysteinemia; further studies are ongoing to understand the underlying mechanism.

Proteomic signatures of serum albumin-bound proteins from stroke patients with and without endovascular closure of PFO are significantly different and suggest a novel mechanism for cholesterol efflux

BACKGROUND

The anatomy of PFO suggests that it can allow thrombi and potentially harmful circulatory factors to travel directly from the venous to the arterial circulation - altering circulatory phenotype. Our previous publication using high-resolution LC-MS/MS to profile protein and peptide expression patterns in plasma showed that albumin was relatively increased in donor samples from PFO-related than other types of ischemic strokes. Since albumin binds a host of molecules and acts as a carrier for lipoproteins, small molecules and drugs, we decided to investigate the albumin-bound proteins (in a similar sample cohort) in an effort to unravel biological changes and potentially discover biomarkers related to PFO-related stroke and PFO endovascular closure.

METHODS

The method used in this study combined albumin immuno-enrichment with high resolution LC-MS in order to specifically capture and quantify the albumin-bound proteins. Subsequently, we measured cholesterol and HDL in a larger, separate cohort of PFO stroke patients, pre and post closure.

RESULTS

The results demonstrated that a number of proteins were specifically associated with albumin in samples with and without endovascular closure of the PFO, and that the protein profiles were very different. Eight proteins, typically associated with HDL were common to both sample sets and quantitatively differently abundant. Pathway analysis of the MS results suggested that enhanced cholesterol efflux and reduced lipid oxidation were associated with PFO closure. Measurement of total cholesterol and HDL in a larger cohort of PFO closure samples using a colorimetric assay was consistent with the proteomic predictions.

CONCLUSIONS

The collective data presented in this study demonstrate that analysis of albumin-bound proteins could provide a valuable tool for biomarker discovery on the effects of PFO endovascular closure. In addition, the results suggest that PFO endovascular closure can potentially have effects on HDL, cholesterol and albumin-bound ApoA-I abundance, therefore possibly providing benefits in cardioprotective functions.