Out with the old: Single center experience with transvenous extraction of leads older than 15 years.

BACKGROUND: Lead dwell time is the single strongest predictor of failure and complications in transvenous lead extraction. OBJECTIVES: To report the success rate and complications of transvenous lead extractions with implant dwell time of at least 15 years. METHODS: Procedural and patient data were prospectively collected into a database. The excimer laser was the primary method for lead extraction with the use of mechanical rotational sheaths and femoral snares at operator discretion. RESULTS: A total of 442 patients between 2011 and 2020 underwent lead extraction (705 leads) primarily for infection or device failure at our high-volume center. Forty-one patients with 71 leads > 15 years old were included in this cohort. Mean patient age was 53.5 ± 18.5 years, 67.5% were male. Mean lead dwell time was 19.6 ± 4.4 years. Thirty-six of 41 (88%) patients had successful extraction of all leads compared to 96% in the remaining 401 patients, p value.004. Of the five patients without fully successful extractions two of these patients had abandoned leads (three total) that were clinically significant. There were two (4.9%) major complications in the very old lead group and six (1.5%) in the other group. In the very old lead group, one patient experienced right atrial appendage perforation requiring surgical repair and recovered well. One patient experienced new complete heart block requiring 2 min of CPR but did well thereafter. There was no procedure-related mortality. CONCLUSIONS: Despite challenges posed by older leads, very old leads can be safely and effectively extracted with low complication rates.

Increased systolic load causes adverse remodeling of fetal aortic and mitral valves.

While abnormal hemodynamic forces alter fetal myocardial growth, little is known about whether such insults affect fetal cardiac valve development. We hypothesized that chronically elevated systolic load would detrimentally alter fetal valve growth. Chronically instrumented fetal sheep received either a continuous infusion of adult sheep plasma to increase fetal blood pressure, or a lactated Ringer's infusion as a volume control beginning on day 126 ± 4 of gestation. After 8 days, mean arterial pressure was higher in the plasma infusion group (63.0 mmHg vs. 41.8 mmHg, P < 0.05). Mitral annular septal-lateral diameter (11.9 mm vs. 9.1 mm, P < 0.05), anterior leaflet length (7.7 mm vs. 6.4 mm, P < 0.05), and posterior leaflet length (P2; 4.0 mm vs. 3.0 mm, P < 0.05) were greater in the elevated load group. mRNA levels of Notch-1, TGF-ß2, Wnt-2b, BMP-1, and versican were suppressed in aortic and mitral valve leaflets; elastin and α1 type I collagen mRNA levels were suppressed in the aortic valves only. We conclude that sustained elevated arterial pressure load on the fetal heart valve leads to anatomic remodeling and, surprisingly, suppression of signaling and extracellular matrix genes that are important to valve development. These novel findings have important implications on the developmental origins of valve disease and may have long-term consequences on valve function and durability.

Midterm Outcomes: A Comprehensive Approach to Surgery for Hypertrophic Obstructive Cardiomyopathy.

BACKGROUND: Left ventricular outflow tract (LVOT) obstruction in obstructive hypertrophic cardiomyopathy (HCM) is caused by a constellation of abnormalities. This study reviewed outcomes of a comprehensive approach to correct these abnormalities during surgery. METHODS: This was a single-institution study of patients with HCM who underwent septal myectomy from 2016 to 2023. Their New York Heart Association functional classification and most recent echocardiogram that estimated LVOT gradient and mitral valve function were tracked. RESULTS: The study included 103 patients with a mean age of 54 years (interquartile range, 40-67 years) and common comorbidities: hypertension (50%) and atrial fibrillation (25%). On average, the preprocedure resting echocardiogram showed an LVOT gradient of 36.4 mm Hg and moderate or severe mitral regurgitation in 50.5% of patients. All patients underwent septal myectomy, and associated abnormalities contributing to LVOT obstruction were addressed. Elongation of the anterior leaflet of the mitral valve was typically treated with papillary muscle realignment (72%). Aberrant papillary muscle heads and elongated secondary chordae tendineae contributing to systolic anterior motion were resected (66%). Myocardial bands, including apicoseptal bands contributing to LVOT obstruction, were resected (68%). With an average follow-up of 4 years, 91% of patients were considered to be in New York Heart Association functional class I or II. Long-term echocardiographic follow-up showed a mean peak LVOT gradient of 11 mm Hg (interquartile range, 4-13 mm Hg). Only 1 patient had more than mild mitral regurgitation. CONCLUSIONS: A comprehensive surgical approach to HCM that addresses the entire constellation of abnormalities associated with HCM, including mitral valve anterior leaflet elongation, aberrant or displaced mitral valve subvalvular apparatus, and myocardial bands, leads to outstanding midterm outcomes.

Impact of fixation mechanism and helix retraction status on right ventricular lead extraction.

Background: The impact of lead fixation mechanism on extractability is poorly characterized. Objective: We aimed to compare the technical difficulty of transvenous lead extraction (TLE) of active vs passive fixation right ventricular (RV) leads. Methods: A total of 408 patients who underwent RV TLE by a single expert electrophysiologist at Oregon Health & Science University between October 2011 and June 2022 were identified and retrospectively analyzed; 331 (81%) had active fixation RV leads and 77 (19%) had passive fixation RV leads. The active fixation cohort was further stratified into those with successfully retracted helices (n = 181) and failed helix retraction (n = 109). A numerical system (0-9) devised using 6 procedural criteria quantified a technical extraction score (TES) for each RV TLE. The TES was compared between groups. Results: Helix retraction was successful in ≥55% of active fixation TLEs. The mean TES for active-helix retracted, active-helix non-retracted, and passive fixation groups was 1.8, 3.5, and 3.7, respectively. The TES of the active-helix retracted group was significantly lower than those of the active-helix non-retracted group (adjusted P < .01) and the passive fixation group (adjusted P < .01). There was no significant difference in TES between the passive fixation and active-helix non-retracted groups in multivariate analysis (P = .18). The TLE success rate of the entire cohort was >97%, with a major complication rate of 0.5%. Conclusion: TLE of active fixation leads where helical retraction is achieved presents fewer technical challenges than does passive fixation RV lead extraction; however, if the helix cannot be retracted, active and passive TLE procedures present similar technical challenges.

Left atrial plication for heart transplantation in patients with giant left atrium.

Giant left atrium occasionally occurs in patients undergoing heart transplantation and causes a technical challenge for the surgeon because of the substantial discrepancy in size between the left atrial cuffs of the recipient and donor. We describe a left atrial plication technique that substantially reduces this discrepancy and allows for a standard left atrial anastomosis to be performed without any other modifications in technique.

Simulating for Quality: A Centralized Quality Improvement and Patient Safety Simulation Curriculum for Residents and Fellows.

PROBLEM: Requirements for experiential education in quality improvement and patient safety (QI/PS) in graduate medical education (GME) have recently expanded. Major challenges to meeting these requirements include a lack of faculty with the needed expertise, paucity of standardized curricular models allowing for skill demonstration, and inconsistent access to data for iterative improvement. APPROACH: In October 2017, the authors began development of a centralized QI/PS flipped-classroom simulation-based medical education (SBME) curriculum for GME trainees across multiple disciplines at Oregon Health & Science University (OHSU). The curriculum development team included OHSU and Veterans Affairs faculty with experience in QI/PS and SBME, as well as house officers. The curriculum consisted of a preassessment and prework readings and videos (sent 3 weeks before the simulation day) and an 8-hour simulation day, with introductory activities, 4 linked simulation sessions, and concluding activities. The 4 linked sessions followed the same medication error from disclosure and reporting to root cause analysis, iterative implementation of an action plan, and consolidation of lessons learned into routine operations with Lean huddles. OUTCOMES: In academic year 2018-2019, 71 residents and fellows of various postgraduate years from 23 training programs enrolled in 2 pilot sessions. Learners reacted favorably to the simulation curriculum. Learner attitudes, confidence, knowledge, and skills significantly increased across all QI/PS domains studied. NEXT STEPS: This approach focuses a small cadre of educators toward the creation of a centralized resource that, owing to its experiential SBME foundation, can accommodate many learners with data-driven practice-based learning and improvement cycles in a shorter time frame than traditional QI initiatives. Next steps include the addition of a control group, assessment of the sustainability of learner outcomes, translation of learning to behavior change and improvements in patient and health system outcomes, and adapting the materials to include learners from different professions and levels.

Septal Myectomy for Obstructive Hypertrophic Cardiomyopathy in the Elderly.

BACKGROUND: Hypertrophic obstructive cardiomyopathy is a genetic disorder treated with septal reduction therapy, either alcohol septal ablation or septal myectomy (SM). Historically older patients have been presumed to be poor candidates for SM and thus referred directly for alcohol septal ablation in some centers. We reviewed our experience with SM in older patients. METHODS: We identified 100 patients at our institution who underwent SM for hypertrophic obstructive cardiomyopathy from 2015 to 2020. Demographic and clinical characteristics and outcomes of patients 65 years or older were compared with patients younger than 65. RESULTS: Sixty-five patients were in the <65 group and 35 patients in the ≥65 group. Both groups had similar preoperative peak stress left ventricular outflow tract gradients (129 mm Hg vs 110 mm Hg, P < .001). Most patients in both groups had moderate to severe mitral regurgitation on preoperative stress echocardiography. The elderly group was more likely to have coronary artery bypass graft as a concomitant procedure (37% vs 8%, P < .001). Only 1 death occurred in the series secondary to a pulmonary embolism. At the 30-day follow-up on stress echocardiography, peak stress gradients were normal in both groups (21 and 20 mm Hg, respectively; P < .001), and 88% of all patients had trace to mild mitral regurgitation. CONCLUSIONS: Properly selected older patients can safely undergo SM with excellent outcomes similar to younger patients. Relief of left ventricular outflow tract obstruction and correction of mitral regurgitation are reliably achieved in both groups. Advanced age should not be a strict criteria for selecting septal reduction therapy approach.

Factor VIII inhibitor bypass activity (FEIBA) for the reduction of transfusion in cardiac surgery: a randomized, double-blind, placebo-controlled, pilot trial.

BACKGROUND: Uncontrolled bleeding after cardiac surgery can be life-threatening. Factor eight inhibitor bypassing activity (FEIBA) is a prothrombin complex concentrate empirically used as rescue therapy for correction of refractory bleeding diathesis post-cardiopulmonary bypass (CPB). FEIBA used as rescue therapy for bleeding diathesis after CPB has been associated with a low incidence of complications and a reduction in transfusion requirement and re-exploration. The feasibility and efficacy of early administration of FEIBA after the termination of CPB have not been studied in a prospective randomized trial. METHODS: We designed a small randomized, double-blinded, placebo-controlled pilot trial to determine the feasibility of a larger trial testing the hypothesis that FEIBA decreases transfusion requirements after CPB. The study was designed to evaluate the feasibility of a larger pivotal trial to determine the effectiveness of FEIBA in reducing the total volume of blood products transfused perioperatively, and its safety profile. Study participants were adult patients undergoing elective major aortic cardiovascular surgery at a tertiary referral hospital, who were equally randomized to receive a single dose of either FEIBA or matched placebo intraoperatively at the end of CPB. RESULTS: Twenty patients were screened and 12 were randomized and included in the analysis. Protocol adherence was high, and all patients received the study drug per intention-to-treat except one patient. There were no protocol deviations or events of unblinding, and adverse events were not different between groups. Patients in the FEIBA group were older and more likely to be female and had higher BMI, lower hematocrit, and longer hypothermic circulatory arrest. There were no differences in post-randomization blood product transfusions (difference FEIBA vs. placebo -899 mL; 95% CI -5206 to 3409) or in the administration of open-label FEIBA. CONCLUSIONS: This pilot trial confirmed the adequacy of the trial design that involved the early, blinded administration of FEIBA, by demonstrating excellent protocol adherence. We conclude that a larger trial establishing the effectiveness of early prothrombin complex concentrate administration to reduce the use of blood products in the setting of high-risk cardiac surgery is feasible. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02577614 . Registered 16 October 2015.

Characterization of 3-dimensional papillary muscle displacement in in vivo ovine models of ischemic/functional mitral regurgitation.

OBJECTIVE: Papillary muscle (PM) displacement contributes to ischemic/functional mitral regurgitation (IMR/FMR). The displaced PMs pull the mitral leaflets into the left ventricle (ie, toward the apex) thus hampering leaflet coaptation. Intuitively apical leaflet tethering results from apical PM displacement. The 3-dimensional directions of PM displacement are, however, incompletely characterized. METHODS: Data from in vivo ovine models of IMR (6-8 weeks of posterolateral infarction, n = 12) and FMR (9-21 days of rapid left ventricular pacing, n = 11) were analyzed. All sheep had radiopaque markers implanted on the anterior and posterior PM (PPM) tips, around the mitral annulus, and on the left ventricular apex. To explore 3-dimensional PM displacement directions, differences in marker coordinates were calculated at end-systole before and during IMR/FMR using a right-handed coordinate system centered on the mitral annular "saddle horn" with the y-axis passing through the apical marker. RESULTS: No apical PM displacement was observed during either IMR or FMR. The anterior PM displaced laterally during FMR. Posterolateral PPM displacement was observed during IMR and FMR. CONCLUSIONS: Experimental in vivo ovine models suggest posterolateral PPM displacement as a predominant pathomechanism leading to apical leaflet tethering during IMR/FMR.

The role of estrogen, immune function and aging in heart transplant outcomes.

BACKGROUND: Aging and loss of estrogen suppress immune function, potentially improving survival after orthotopic heart transplant (OHT). The effect of female aging on OHT outcomes is unknown. METHODS: Between 1995 and 2015, 41,299 adult OHT recipients (24.3% women) were studied using a retrospective multi-institutional cohort. Patients were stratified by age and gender into premenopausal (18-39 years), perimenopausal (40-49 years), and postmenopausal (≥50 years) groups. Kaplan-Meier survival analyses and risk-adjusted models examined gender differences across groups at one, five, and ten years. RESULTS: Kaplan-Meier survival was equivalent for postmenopausal women and men, and lower for premenopausal women than men at all time points (p ≤ 0.05). Postmenopausal women had higher risk-adjusted five-year survival than premenopausal women (AOR 1.61, 95% CI 1.15-2.25, p = 0.006). CONCLUSIONS: Premenopausal women have lower unadjusted survival than men after OHT. Post-menopausal women have significantly better five-year survival than pre-menopausal women. Menopause may contribute to improved survival after OHT.

Early post-approval experience with transcatheter aortic valve replacement in the USA.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) is changing the treatment of aortic stenosis. We compared cost and clinical outcomes of TAVR versus surgical aortic valve repair (SAVR) in the real-world setting since USA TAVR approval in 2012. METHODS: The Nationwide Inpatient Sample (NIS) dataset was analyzed by quarter (June 2012 to December 2014). Patients (>65 years old) undergoing TAVR or SAVR were identified and risk stratified based on APR-DRG Mortality risk score. Outcomes were in-hospital mortality, length of stay (LOS), discharge location, and hospitalization cost. RESULTS: TAVR cases per quarter increased from 1900 to 5445 over the study period. TAVR patients were older and had more comorbidities (P<0.001). TAVR patients had longer LOS (8 vs. 7 days; P<0.001), were less likely to discharge to home (67% vs. 73%; P<0.001), had higher inpatient mortality (5.5% vs. 0.69%; P<0.001) and overall hospital cost ($ 227,985 vs. $ 148,019; P<0.001) than SAVR patients. On multivariate analysis TAVR was associated with increased cost (ß=0.42; P<0.001) and increased mortality (OR=5.228, CI: 3.508-7.791; P<0.001) but not associated with increased LOS (ß=0.297; P=0.078) or discharge to facility (OR=1.004, CI: 0.833-1.213; P=0.960). In the last two quarters of 2014 there was no difference between TAVR and SAVR LOS, however TAVR cost did not decrease over the study period. CONCLUSIONS: TAVR patients represented a sicker population, however LOS and discharge location outcomes were equivalent to SAVR. TAVR remained significantly more expensive across all risk groups and cost did not fall over the course of the study.

Tenting volume: three-dimensional assessment of geometric perturbations in functional mitral regurgitation and implications for surgical repair.

BACKGROUND AND AIM OF THE STUDY: Functional mitral regurgitation (FMR) often complicates dilated cardiomyopathy (DCM), and portends a poor prognosis. Debate over the optimal treatment continues, underscoring the present incomplete understanding of the patho-anatomic mechanisms of this disease. Studies of mitral tenting volume and tenting area, and echocardiographic measures of abnormal apical systolic leaflet geometry have linked mitral leaflet deformation with subvalvular left ventricular (LV) remodeling in chronic ischemic MR. The relative contributions of annular versus subvalvular remodeling in FMR due to DCM are less clear. Here, the validity of 3-D measurement of mitral deformation, tenting volume, as a correlate of MR in DCM, was tested. The ability of annular and subvalvular remodeling to predict mitral deformation was then determined. METHODS: Eight sheep underwent placement of radiopaque markers on the mitral annulus and leaflets. Global LV, annular and subvalvular geometry, as well as mitral tenting height, area and volume were calculated before (Control) and after the development of pacing-induced cardiomyopathy and MR (DCM). Multivariable regression determined which measure of mitral deformation was the best predictor of MR. Regression analysis was also used to find geometric predictors of mitral tenting volume. RESULTS: In a multivariable analysis, mitral tenting volume was the only independent predictor of severity of MR (r(2) = 0.79, standard error of estimate (SEE) = 0.58). Increased tenting volume correlated best with increased mitral annular septal-lateral diameter (r(2) = 0.67, SEE = 0.72). CONCLUSION: The 3-D tenting volume correlates best with severity of FMR. Mitral deformation (increased tenting volume) observed in DCM is predicted by annular dilation, but not by subvalvular LV remodeling. These data support the use of an undersized annuloplasty in DCM complicated by FMR, and may guide the rational design of new therapies for this vexing disease.

Septal-lateral annnular cinching perturbs basal left ventricular transmural strains.

OBJECTIVE: Septal-lateral annular cinching ('SLAC') corrects both acute and chronic ischemic mitral regurgitation in animal experiments, which has led to the development of therapeutic surgical and interventional strategies incorporating this concept (e.g., Edwards GeoForm ring, Myocor Coapsys, Ample Medical PS3). Changes in left ventricular (LV) transmural cardiac and fiber-sheet strains after SLAC, however, remain unknown. METHODS: Eight normal sheep hearts had two triads of transmural radiopaque bead columns inserted adjacent to (anterobasal) and remote from (midlateral equatorial) the mitral annulus. Under acute, open chest conditions, 4D bead coordinates were obtained using videofluoroscopy before and after SLAC. Transmural systolic strains were calculated from bead displacements relative to local circumferential, longitudinal, and radial cardiac axes. Transmural cardiac strains were transformed into fiber-sheet coordinates (X(f), X(s), X(n)) oriented along the fiber (f), sheet (s), and sheet-normal (n) axes using fiber (alpha) and sheet (beta) angle measurements. RESULTS: SLAC markedly reduced (approximately 60%) septal-lateral annular diameter at both end-diastole (ED) (2.5+/-0.3 to 1.0+/-0.3 cm, p=0.001) and end-systole (ES) (2.4+/-0.4 to 1.0+/-0.3 cm, p=0.001). In the LV wall remote from the mitral annulus, transmural systolic strains did not change. In the anterobasal region adjacent to the mitral annulus, ED wall thickness increased (p=0.01) and systolic wall thickening was less in the epicardial (0.28+/-0.12 vs 0.20+/-0.06, p=0.05) and midwall (0.36+/-0.24 vs 0.19+/-0.11, p=0.04) LV layers. This impaired wall thickening was due to decreased systolic sheet thickening (0.20+/-0.8 to 0.12+/-0.07, p=0.01) and sheet shear (-0.15+/-0.07 to -0.11+/-0.04, p=0.02) in the epicardium and sheet extension (0.21+/-0.11 to 0.10+/-0.04, p=0.03) in the midwall. Transmural systolic and remodeling strains in the lateral midwall (remote from the annulus) were unaffected. CONCLUSIONS: Although SLAC is an alluring concept to correct ischemic mitral regurgitation, these data suggest that extreme SLAC adversely effects systolic wall thickening adjacent to the mitral annulus by inhibiting systolic sheet thickening, sheet shear, and sheet extension. Such alterations in LV strains could result in unanticipated deleterious remodeling and warrant further investigation.