Cytomegalovirus IgG is Associated With Physical Function But Not Muscle Density in People With HIV.

BACKGROUND: Cytomegalovirus (CMV) seropositivity is associated with poor outcomes, including physical function impairment, in people without HIV. We examined associations between CMV IgG titer and physical function in virologically suppressed people with HIV (PWH). METHODS: REPRIEVE is a double-blind randomized trial evaluating pitavastatin for primary prevention of atherosclerotic cardiovascular disease in PWH. This analysis focused on participants enrolled in a substudy with additional biomarker testing, imaging [coronary CT angiography], and physical function measures at entry. CMV IgG was measured using quantitative enzyme immunoassay, physical function by Short Physical Performance Battery, and muscle density and area by CT. Associations between CMV IgG (risk factor) and outcomes were evaluated using the partial Spearman correlation and linear and log-binomial regression. RESULTS: Among 717 participants, 82% male, the median CMV IgG was 2716 (Q1, Q3: 807, 6672) IU/mL, all above the limit of quantification. Among 631 participants with imaging, there was no association between CMV IgG and CT-based muscle density or area, controlling for age (r = -0.03 and r = -0.01, respectively; P ≥ 0.38). Among 161 participants with physical function data, higher CMV IgG was associated with poorer overall modified Short Physical Performance Battery score ( P = 0.02), adjusted for age, nadir CD4, and high-sensitivity C-reactive protein. CONCLUSIONS: Higher CMV IgG titer was associated with poorer physical function, not explained by previous immune compromise, inflammation, or muscle density or area. Further mechanistic studies are needed to understand this association and whether CMV-specific therapy can affect physical function in PWH.

Biological and Clinical Implications of the Vascular Endothelial Growth Factor Coreceptor Neuropilin-1 in Human Immunodeficiency Virus.

Plasma vascular endothelial growth factor (VEGF) coreceptor neuropilin-1 (NRP-1) had the largest association with coronary plaque in the Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE) proteomics analysis. With little known about NRP-1 in people with human immunodeficiency virus (PWH), we explored its relation to other proteins in REPRIEVE and validated our findings through a Centers for AIDS Research Network of Integrated Clinical Systems (CNICS) case-cohort study by assessing its relation to host factors and incident cardiovascular disease and cancer. Within REPRIEVE, NRP-1 was associated with proteins involved in angiogenesis, signal transduction, immunoregulation, and cell migration/adhesion. Within CNICS, NRP-1 was associated with key host factors, including older age and male sex. NRP-1 was associated with an increased hazard of multiple cancers but a decreased prostate cancer risk. Finally, NRP-1 was most strongly associated with mortality and type 2 myocardial infarction. These data suggest that NRP-1 is part of a clinically relevant immunoregulatory pathway related to multiple comorbidities in PWH. Clinical Trials Registration. NCT02344290.

Beyond Undetectable: Modeling the Clinical Benefit of Improved Antiretroviral Adherence in Persons With Human Immunodeficiency Virus With Virologic Suppression.

Background: Incomplete antiretroviral therapy (ART) adherence has been linked to deleterious immunologic, inflammatory, and clinical consequences, even among virally suppressed (<50 copies/mL) persons with human immunodeficiency virus (PWH). The impact of improving adherence in the risk of severe non-AIDS events (SNAEs) and death in this population is unknown. Methods: We estimated the reduction in the risk of SNAEs or death resulting from an increase in ART adherence by (1) applying existing data on the association between adherence with high residual inflammation/coagulopathy in virally suppressed PWH, and (2) using a Cox proportional hazards model derived from changes in plasma interleukin 6 (IL-6) and D-dimer from 3 randomized clinical trials. Comparatively, assuming 100% ART adherence in a PWH who achieves viral suppression, we estimated the number of persons in whom a decrease in adherence to <100% would need to be observed for an additional SNAE or death event to occur during 3- and 5-year follow-up. Results: Increasing ART adherence to 100% in PWH who are suppressed on ART despite imperfect adherence translated into a 6%-37% reduction in the risk of SNAEs or death. Comparatively, based on an anticipated 12% increase in IL-6, 254 and 165 PWH would need to decrease their adherence from 100% to <100% for an additional event to occur over 3- and 5-year follow-up, respectively. Conclusions: Modest gains in ART adherence could have clinical benefits beyond virologic suppression. Increasing ART adherence (eg, via an intervention or switch to long-acting ART) in PWH who remain virally suppressed despite incomplete adherence should be evaluated.

Coronary Artery Plaque Composition and Severity Relate to the Inflammasome in People With Treated Human Immunodeficiency Virus.

Background: Inflammasome activation is increased in people with human immunodeficiency virus (PWH), but its relationship with coronary plaque is poorly understood in this setting. Methods: In a large human immunodeficiency virus cardiovascular prevention cohort, relationships between caspase-1, interleukin (IL)-1ß, and IL-18 and coronary plaque indices were assessed by multivariate logistic regression. Results: Higher IL-18 and IL-1ß were associated with Leaman score, an integrative measure of plaque burden and composition. Conclusions: As Leaman score >5 is associated with cardiovascular events in the general population, future work is needed to determine how the inflammasome relates to events and whether strategies to reduce its activation affect events or plaque progression among PWH.

Babesia microti Variant With Multiple Resistance Mutations Detected in an Immunocompromised Patient Receiving Atovaquone Prophylaxis.

We report Babesia microti genomic sequences with multiple mutations in the atovaquone-target region of cytochrome b, including a newly identified Y272S mutation, plus 1 mutation of undetermined significance in the azithromycin-associated ribosomal protein L4. The parasite was sequenced from an immunocompromised patient on prophylactic atovaquone for Pneumocystis pneumonia before diagnosis of babesiosis.

Effect of host factors and COVID-19 infection on the humoral immune repertoire in treated HIV.

People with HIV (PWH) appear to be at higher risk for suboptimal pathogen responses and for worse COVID-19 outcomes, but the effects of host factors and COVID-19 on the humoral repertoire remain unclear. We assessed the antibody isotype/subclass and Fc-receptor binding Luminex arrays of non-SARS-CoV-2 and SARS-CoV-2 humoral responses among antiretroviral therapy-treated (ART-treated) PWH. Among the entire cohort, COVID-19 infection was associated with higher cytomegalovirus (CMV) responses (vs. the COVID- cohort ), potentially signifying increased susceptibility or a consequence of persistent inflammation. Among the COVID+ participants, (a) higher BMI was associated with a striking amplification of SARS-CoV-2 responses, suggesting exaggerated inflammatory responses, and (b) lower nadir CD4 was associated with higher SARS-CoV-2 IgM and FcγRIIB binding capacity, indicating poorly functioning extrafollicular and inhibitory responses. Among the COVID-19- participants, female sex, older age, and lower nadir CD4 were associated with unique repertoire shifts. In this first comprehensive assessment of the humoral repertoire in a global cohort of PWH, we identify distinct SARS-CoV-2-specific humoral immune profiles among PWH with obesity or lower nadir CD4+ T cell count, underlining plausible mechanisms associated with worse COVID-19-related outcomes in this setting. Host factors associated with the humoral repertoire in the COVID-19- cohort enhance our understanding of these important shifts among PWH.

Cytomegalovirus Immunoglobulin G (IgG) Titer and Coronary Artery Disease in People With Human Immunodeficiency Virus (HIV).

BACKGROUND: Cytomegalovirus (CMV) infection is thought to result in increased immune activation in people with human immunodeficiency virus (HIV, PWH). Although some data have linked asymptomatic CMV infection to cardiovascular disease among PWH, it remains unknown whether CMV is associated with increased or high-risk coronary plaque. METHODS: The Randomized Trial to Prevent Vascular Events in HIV (REPRIEVE) enrolled PWH aged 40-75 years on stable antiretroviral therapy (ART) with low-to-moderate atherosclerotic cardiovascular disease (ASCVD) risk. Among a subset of US REPRIEVE participants, coronary plaque was assessed by coronary computed tomography angiography. Here, we assessed the relationship between CMV immunoglobulin G (IgG) titer and (1) levels of immune activation, (2) inflammatory biomarkers, and (3) coronary plaque phenotypes at study entry. RESULTS: Of 672 participants, mean age was 51 years, 83% were men, median ASCVD risk score was 4.5%, and 66% had current CD4+ T-cell count ≥500 cells/mm3. Higher CMV IgG quartile group was associated with older age and lower current and nadir CD4+ T-cell counts. CMV IgG titer was associated with specific inflammatory biomarkers (sCD163, MCP-1, interleukin [IL]-6, hsCRP) in univariate analysis, but not after controlling for HIV-specific factors. In contrast, CMV IgG titer was not associated with coronary artery disease indexes, including presence of plaque, coronary artery calcium (CAC) score >0, vulnerable plaque presence, or Leaman score >5. CONCLUSIONS: No meaningful association was seen between CMV IgG titer and coronary artery disease indexes among ART-treated PWH at study enrollment. Longitudinal assessments in REPRIEVE will determine the relationship of CMV IgG titer to plaque progression and cardiovascular events. CLINICAL TRIALS REGISTRATION: NCT02344290.

Increased Macrophage-Specific Arterial Infiltration Relates to Noncalcified Plaque and Systemic Immune Activation in People With Human Immunodeficiency Virus.

BACKGROUND: Persistent immune activation is thought to contribute to heightened atherosclerotic cardiovascular disease (ASCVD) risk among people with human immunodeficiency virus (PWH). METHODS: Participants (≥18 years) with or without human immunodeficiency virus (HIV) and without history of clinical ASCVD were enrolled. We hypothesized that increased macrophage-specific arterial infiltration would relate to plaque composition and systemic immune activation among PWH. We applied a novel targeted molecular imaging approach (technetium-99m [99mTc]-tilmanocept single photon emission computed tomography [SPECT]/CT) and comprehensive immune phenotyping. RESULTS: Aortic 99mTc-tilmanocept uptake was significantly higher among PWH (n = 20) than participants without HIV (n = 10) with similar 10-year ASCVD risk (P = .02). Among PWH, but not among participants without HIV, noncalcified aortic plaque volume related directly to aortic 99mTc-tilmanocept uptake at different uptake thresholds. An interaction (P = .001) was seen between HIV status and noncalcified plaque volume, but not calcified plaque (P = .83). Systemic levels of caspase-1 (P = .004), CD14-CD16+ (nonclassical/patrolling/homing) monocytes (P = .0004) and CD8+ T cells (P = .005) related positively and CD4+/CD8+ T-cell ratio (P = .02) inversely to aortic 99mTc-tilmanocept uptake volume. CONCLUSIONS: Macrophage-specific arterial infiltration was higher among PWH and related to noncalcified aortic plaque volume only among PWH. Key systemic markers of immune activation relating to macrophage-specific arterial infiltration may contribute to heightened ASCVD risk among PWH. CLINICAL TRIALS REGISTRATION: NCT02542371.

Immune Activation in Primary Human Immunodeficiency Virus: Influence of Duration of Infection, Treatment, and Substance Use.

Background: Primary human immunodeficiency virus (HIV) is characterized by dynamic changes in viral load and innate and adaptive immune responses; it is unclear the extent to which time from acquisition to antiretroviral therapy (ART) initiation and substance use impact these immunologic changes. Methods: We studied plasma immune activation biomarkers, viral load, and CD4+ and CD8+ cell counts in participants from the Sabes primary infection study in Peru, who had been randomized to begin ART immediately after diagnosis vs 24 weeks later. We modeled influence of substance use and duration of HIV infection on biomarkers at baseline and over 24 weeks. Results: Compared to participants enrolled >30 days after HIV acquisition, participants enrolled during acute infection (≤30 days) had higher mean interferon (IFN)-γ and IFN-α2a (1.7-fold and 3.8-fold interquartile range [IQR] higher, respectively). Participants enrolled >30 days after HIV acquisition had higher mean baseline CD8+ cell count (2.7 times the IQR). Alcohol use (positive phosphatidylethanol level) was associated with elevated IFN-γ, tumor necrosis factor alpha (TNF-α), and interleukin 12p70 (IL-12p70), and smoking was associated with higher macrophage inflammatory protein 1α, TNF-α, and IL-12p70. Most biomarkers declined more quickly in participants who initiated ART immediately; however, substance use and duration of HIV infection at enrollment had little influence on rate of decline. Conclusions: IFN-γ and other biomarkers are elevated during early primary infection, when exposure to HIV antigens is high. Immune activation decreased most quickly in those who started ART during acute/early primary infection. Higher CD8+ cell counts and a trend toward higher soluble CD163 levels during the 30 days after acquisition suggest the onset of compensatory responses and immune exhaustion.

Changes in Immune Activation During Pregnancy and the Postpartum Period in Treated HIV Infection.

BACKGROUND: Pregnant women with HIV (PWWH) have high postpartum morbidity and mortality from infections like tuberculosis. Immunologic changes during pregnancy and postpartum periods may contribute to these risks, particularly the immunoregulatory kynurenine pathway of tryptophan catabolism, which contributes to both HIV and tuberculosis pathogenesis and increases in the early postpartum period. METHODS: Women with HIV initiating antiretroviral therapy (ART) in the Uganda AIDS Rural Treatment Outcomes (UARTO) cohort who were pregnant at enrollment or became pregnant during observation were studied (n = 54). Plasma kynurenine/tryptophan (KT) ratio, soluble CD14 (sCD14), sCD163, sCD27, interferon-inducible protein 10 (IP-10), D-dimer, interleukin-6, and intestinal fatty-acid binding protein levels were assessed through the first year of ART and at 3-month intervals throughout pregnancy and 1 year postpartum. Biomarker changes were assessed with linear mixed models adjusted for ART duration. Hemoglobin concentration changes were used to estimate pregnancy-related changes in plasma volume. RESULTS: The median pre-ART CD4 count was 134. D-dimer increased through the third trimester before returning to baseline postpartum, while most other biomarkers declined significantly during pregnancy, beyond what would be expected from pregnancy-associated plasma volume expansion. IP-10 and sCD14 remained suppressed for at least 12 months postpartum. KT ratio was the only biomarker that increased above prepregnancy baseline postpartum (mean + 30%; P < .001) and remained higher than baseline for ≥9 months (P ≤ .045 for all time points). CONCLUSIONS: Several immune activation markers decline during pregnancy and remain suppressed postpartum, but the kynurenine pathway of tryptophan catabolism increases above baseline for ≥9 months postpartum. The mechanisms underlying postpartum kynurenine pathway activity are incompletely understood but may contribute to increased tuberculosis risk in this setting.

Clinical consequences of asymptomatic cytomegalovirus in treated human immunodeficency virus infection.

PURPOSE OF REVIEW: Despite antiretroviral therapy (ART)-mediated viral suppression, people with human immunodeficiency virus (HIV) (PWH) have increased morbidity and mortality. Immune activation and inflammation persist on ART and predict these complications. Over 90% of PWH have cytomegalovirus (CMV) co-infection, and CMV is considered a plausible contributor to this persistent immune activation. RECENT FINDINGS: A detailed understanding of the link between CMV and multimorbidity is needed, particularly as research moves toward identifying potential targeted therapeutics to attenuate inflammation-mediated morbidity and mortality in treated HIV. We review the literature on the association between CMV and immune activation as well as multiple end-organ complications including cardiovascular disease, venous thromboembolic disease, metabolic complications, gastrointestinal dysfunction, central nervous system involvement, birth sex-related differences, and the relation to the HIV reservoir. We conclude with a discussion of ongoing therapeutic efforts to target CMV. SUMMARY: As CMV is a plausible driver of multiple comorbidities through persistent immune activation in treated HIV, future research is needed and planned to address its causal role as well as to test novel therapeutics in this setting.

Abnormal Levels of Some Biomarkers of Immune Activation Despite Very Early Treatment of Human Immunodeficiency Virus.

BACKGROUND: Despite early antiretroviral therapy (ART), ART-suppressed people with human immunodeficiency virus (HIV) (PWH) remain at higher risk for infections and infection-related cancers than the general population. The immunologic pathways that remain abnormal in this setting, potentially contributing to these complications, are unclear. METHODS: ART-suppressed PWH and HIV-negative controls, all cytomegalovirus seropositive and enriched for HIV risk factors, were sampled from an influenza vaccine responsiveness study. PWH were stratified by timing of ART initiation (within 6 months of infection [early ART] vs later) and nadir CD4+ T-cell count among later initiators. Between-group differences in kynurenine-tryptophan (KT) ratio, interferon-inducible protein 10, soluble CD14 and CD163, soluble tumor necrosis factor receptor 2, interleukin 6, and soluble urokinase plasminogen activator receptor were assessed after confounder adjustment. RESULTS: Most participants (92%) were male, reflecting the demographics of early-ART initiators in San Francisco. Most biomarkers were higher among later-ART initiators. Participants in the early-ART group achieved near-normal soluble tumor necrosis factor receptor 2, interleukin 6, and soluble urokinase plasminogen activator receptor levels, but substantially higher KT ratio than those without HIV after confounder adjustment (P = .008). Soluble CD14, soluble CD163, and interferon-inducible protein 10 trended similarly. CONCLUSIONS: While early-ART initiators restore near-normal levels of many inflammatory markers, the kynurenine pathway of tryptophan catabolism remains abnormally high. Because this pathway confers adaptive immune defects and predicts tuberculosis and cancer progression, this it may contribute to persistent risks of these complications in this setting.

Brief Report: Heplisav-B Seroprotection in People With HIV: A Single-Center Experience.

BACKGROUND: Heplisav-B, a hepatitis B virus (HBV) vaccine with an immunostimulatory adjuvant, was FDA approved in 2017 for adults ≥18 years. In randomized controlled trials, Heplisav-B demonstrated seroprotection rates (SPR) of 90%-95% versus 65%-80% for Engerix-B. No studies have included people with HIV (PWH), and the SPR and its predictors in this population are unknown. SETTING: Quaternary care center HIV clinic. METHODS: This retrospective cohort study evaluated PWH aged ≥18 years without current HBV seroprotection (anti-HBV surface antibody level [anti-HBs] <10 mIU/mL) who were administered Heplisav-B. Patients without post-immunization titers were excluded. The primary outcome was the SPR, the proportion of participants with HBV seroprotection at any point after the first vaccination. RESULTS: Among 64 PWH included, median time to anti-HBs measurement after vaccination was 13 weeks. The median age was 58 years, 81% were men, and 95% had a viral load <200. The SPR was 81% in the entire cohort (and 86% in those without significant non-HIV immunosuppression), 79% in those with no prior HBV vaccination and no anti-HBc positivity, and 84% in those with prior vaccine nonresponse. Lower current and nadir CD4+ counts were associated with progressively lower seroprotection. CONCLUSION: In the first single-center retrospective study of Heplisav-B in PWH, the SPR compared favorably with the SPR seen among PWH from prior HBV vaccines across key subgroups. Given these findings, Heplisav-B should be considered for expanded use for HBV vaccination in PWH. Further research on the effectiveness of a repeat vaccination series or higher dosing in nonresponders is needed.

Novel predictors of mild paravalvular aortic regurgitation in SAPIEN 3 transcatheter aortic valve implantation.

AIMS: Paravalvular leak (PVL) remains an important issue in TAVI. The Edwards SAPIEN 3 (S3) valve has reduced PVL but in up to one third of patients mild leak remains. Our study aimed to identify predictors of mild PVL after TAVI with the S3 valve. METHODS AND RESULTS: From October 2015 to May 2017, 122 consecutive patients underwent S3 TAVI for symptomatic severe aortic stenosis. Thirty-three patients with mild PVL on transthoracic echocardiography at 30-day follow-up were compared to 89 with none/trace PVL. Thirty-day mortality was 2.5% (n=3), with zero stroke and major vascular complications. There were no differences between the two groups in patient characteristics, annular and left ventricular outflow tract (LVOT) sizing, distribution and severity of annular calcification, valve implantation technique, post-dilatation and implant depth. Mild PVL was associated with higher annular eccentricity (p=0.04) and moderate-severe LVOT calcification (p=0.03). Independent predictors of mild PVL were LVOT eccentricity (OR 1.05 per % ellipticity, 95% CI: 1.02-1.09, p=0.005), discordant sizing (OR 3.08, 95% CI: 1.20-7.90, p=0.02) and three-leaflet calcification (OR 13.3, 95% CI: 2.66-66.7, p=0.002). CONCLUSIONS: LVOT eccentricity and discordant sizing predict PVL after S3 TAVI. Further studies are needed to understand their mechanism and significance.

Survival and long-term outcomes after mitral valve replacement in patients aged 18 to 50 years.

OBJECTIVE: To provide long-term data on survival and major morbidity after mitral valve replacement in patients aged 18 to 50 years. METHODS: Retrospective analysis of 2727 patients aged 18 to 50 years who underwent isolated mitral replacement in California and New York from 1997 to 2006. Median follow-up time was 12.4 years (maximum 15.0 years). The primary endpoint was mortality; secondary endopoints were stroke, major bleeding, and reoperation. Propensity matching yielded 373 patient pairs. RESULTS: Bioprosthetic valve use increased from 10% to 34% between 1997 and 2014 (P < .001). Among propensity score-matched patients, actuarial 15-year survival was 74.3% (95% confidence interval [CI], 69.0%-78.7%) after bioprosthetic versus 80.8% (95% CI, 75.1%-85.3%) mechanical valve replacement (hazard ratio [HR], 1.67; 95% CI, 1.21-2.32, P = .002). At 15 years after mitral valve replacement, the cumulative incidence of stroke was similar (9.1% [95% CI, 6.0%-13.0%] vs 9.7% [95% CI, 6.7-13.4]; HR, 0.95 [95% CI, 0.57-1.59]); the cumulative incidence of major bleeding events was similar (7.9% [95% CI, 5.0%-11.5%] vs 11.5% [95% CI, 7.6%-16.2%]; HR, 0.78 [95% CI, 0.46-1.32]); and the cumulative incidence of reoperation after bioprosthetic valve replacement was greater (19.9% [95% CI, 15.4%-24.8%] vs 5.7% [95% CI, 3.5%-8.7%]; HR, 20.3 [95% CI, 4.0-102.8]), respectively. CONCLUSIONS: The significant survival benefit associated with mechanical mitral valve replacement in adults ≤50 years may be due to the practice of implanting bioprostheses in sicker patients or those judged less likely to comply with long-term medication despite adjustment for baseline characteristics in propensity score matching.

Bioprosthetic aortic valve replacement: Revisiting prosthesis choice in patients younger than 50 years old.

OBJECTIVE: Aortic prosthesis choice is controversial in young adults because robust comparative outcome data are lacking. We therefore compared mortality and morbidity in young adults after bioprosthetic versus mechanical aortic valve replacement. METHODS: This was a retrospective analysis of 5111 patients aged 18 to 50 years undergoing primary aortic valve replacement in California and New York State from 1997 to 2006. Median follow-up time was 11.8 years (maximum 18.9 years). The primary endpoint was mortality; secondary endpoints were stroke, bleeding, and reoperation. Propensity score matching yielded 1175 patient pairs. RESULTS: Bioprosthetic valves increased from 14% to 47% of aortic valve replacements between 1997 and 2014 (P < .001). There was no survival difference with bioprosthetic versus mechanical aortic valves in the propensity score-matched cohort: actuarial 15-year survival was 79.0% (95% confidence interval [CI], 75.8%-81.8%) versus 81.5% (95% CI, 78.5%-84.2%) respectively (hazard ratio [HR], 1.14; 95% CI, 0.93-1.40, P = .20). No interaction was found between age and prosthesis choice on survival (Pinteraction = 0.16). After bioprosthetic valve replacement, stroke rates were lower (5.4% [95% CI, 3.8%-7.2%] vs 8.1% [95% CI, 6.3%-10.2%], HR 0.62 [95% CI 0.43-0.91]), bleeding rates were lower (4.2% [95% CI, 3.0-5.6%] vs 8.4% [95% CI, 6.6-10.4%], HR 0.48 [95% CI, 0.33-0.69]), but reoperation rates were greater (24.5% [95% CI, 21.3%-27.8%] vs 9.3% [95% CI, 7.2%-11.7%], HR 5.9 [95% CI 3.2-11.0]) at 15 years versus mechanical valve replacement. CONCLUSIONS: Although lifetime risks are represented incompletely, these findings suggest that in adults aged 18-50 years, bioprostheses are a reasonable alternative to mechanical valves for aortic valve replacement.

Ross Procedure Following a Dislodged Transcatheter Aortic Valve Replacement.

A 36-year-old pregnant woman with a history of rheumatic heart disease and prior aortic valve replacement and mitral valve repair presented to an outside hospital with severe aortic stenosis. The patient had a cardiac arrest upon labor induction and underwent a transcatheter aortic valve replacement (TAVR), which dislodged two days later. Five months later, the patient underwent removal of the dislodged TAVR and a Ross procedure at the authors' institution. The patient was stable upon discharge, with minimal aortic and pulmonary regurgitation. To the authors' knowledge, the present report is the first of the Ross procedure being used under such circumstances. It is suggested that caution be taken when using bioprosthetic and transcatheter aortic valves in young patients, and primary use of the Ross procedure is encouraged at experienced centers.

Feasibility of Intraoperative Extubation in Pediatric Heart Transplantation.

Based on described benefits of fast-tracking and early extubation in children undergoing congenital heart surgery, we applied this concept to selected children following uncomplicated orthotopic heart transplantation (OHT). In this case series, we report four patients who were extubated immediately after surgery in the operating room. A mild respiratory acidosis and hypercapnia were noted on the initial arterial blood gases, were well tolerated, and were normalized within 6 to 12 hours. There was no mortality among patients who were extubated in the operating room, and no patients required reintubation. We conclude that operating room extubation is feasible in selected patients undergoing OHT.