Miranda, William R

Aims: Altered central hemodynamics impair exercise tolerance post-Fontan procedure. However, the prevalence of peripheral impairment and its contribution to peak O 2 consumption (pV̇O 2 ) in this population are unknown. Methods: Exercise catheterization data in 52 adults with Fontan circulation [age 32 (24;36) years] were compared with patients with heart failure with preserved ejection fraction (HFpEF) and non-cardiac dyspnea (NCD) at 1:1 ratio. Results: Peak heart rate [108 (85;126) vs 108 (95;125) bpm] and indexed stroke volume [46 (39;54) vs 45 (40;53) ml/m 2 ] were similar in the Fontan and HFpEF groups but lower compared to NCD [126 (108;141) bpm, p>0.001 and 51 (45;59) ml/m 2 , p>0.001]. Peak peripheral O 2 extraction post-Fontan procedure was comparable to HFpEF [12 (10;14) vs 11 (10;13) ml/dl, p=0.17] but higher than in NCD [10 (9;12) ml/dl, p>0.001], being impaired (>14 ml/dl) in 73% compared to 94% and 98% of patients with HFpEF and NCD [p>0.001]. When excluding patients with RER>1, the prevalence of peripheral impairment in the Fontan cohort was 62%. Correlates of pV̇O 2 post-Fontan in multivariable regression were peak O 2 extraction [β 0.5±0.1 per ml/dl; p>0.001], mPAP [β −0.2±0.05 per mmHg; p=0.002], heart rate [β 0.03±0.01 per bpm; p=0.01], and systolic arterial blood pressure [β 0.03±0.01 per mmHg; p=0.02]. Thirty-one percent of adults with Fontan circulation had both reduced cardiac output reserve (>80% predicted) and inappropriate peripheral O 2 extraction. Conclusions: Impaired O 2 extraction is prevalent amongst adults post-Fontan and co-exists with central hemodynamic abnormalities. Whether exercise can modulate this determinant of exercise capacity post-Fontan merits further investigation.

BACKGROUND: Some symptomatic patients manifest pulmonary hypertension (PH), despite normal pulmonary vascular resistance and pulmonary artery wedge pressure—a condition termed unclassified PH. Although hypothesized to reflect increased flow as seen in congenital heart disease, broader clinical implications remain unknown. METHODS: The current analysis included pulmonary vascular disease phenomics participants with either no PH or unclassified PH who underwent dynamic right heart catheterization and transpulmonary metabolomics. In a validation cohort, patients with no PH or unclassified PH underwent exercise right heart catheterization. In exploratory cohorts to understand the impact of increased flow, the prevalence of unclassified PH was assessed in (1) adult congenital heart disease and (2) high output heart failure. RESULTS: The overall prevalence of unclassified PH in pulmonary vascular disease phenomics (n=1046) and the validation cohort (n=1202) was 7.8% (175/2248), which was comparable to the 6.6% (66/1005) prevalence in adult congenital heart disease (n=1005), and lower than high output heart failure (n=159, prevalence 14.5% [23/159]; P =0.006). Increased flow occurred in a minority of unclassified PH from both pulmonary vascular disease phenomics (28%; 15/53) and the validation cohort (11%; 13/122). Unclassified PH (n=53) was associated with greater adiposity, higher heart failure with preserved ejection fraction (HFpEF)–age, body mass index, atrial fibrillation score probability, and more left heart remodeling compared with those with no PH (n=216). Metabolomics revealed lower glycine metabolites in unclassified PH indicative of metabolic dysfunction. Left heart remodeling, quality of life, exercise capacity, and glycine levels were all abnormal in unclassified PH relative to healthy controls (n=96). In the validation cohort, pulmonary artery wedge pressure, pulmonary vascular resistance, and pulmonary artery compliance were subtly abnormal at rest in unclassified PH (n=122) compared with no PH (n=312). With exercise testing, 59% (72/122) with unclassified PH had exertional pulmonary artery wedge pressure elevation consistent with undiagnosed HFpEF. CONCLUSIONS: The presence of PH without obvious cause most often reflects subclinical left heart and metabolic dysfunction consistent with unrecognized early-stage HFpEF. Dynamic provocation during right heart catheterization can unmask unrecognized HFpEF in over half of unclassified PH, which may help guide appropriate initiation of proven HFpEF therapies to improve symptoms and functional status. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02980887.

BACKGROUND: With pulmonary hypertension (PH), a pulmonary artery wedge pressure (PAWP)>15 mm Hg is used to diagnose left heart dysfunction, but some patients with adjudicated group 1 PH demonstrate PAWP>15 mm Hg. The primary objective of the study was to evaluate group 1 PH with high PAWP>15 mm Hg. METHODS: Patients with adjudicated group 1 PH from PVDOMICS between 2016 and 2019 were separated into high PAWP(>15 mm Hg) or normal PAWP and compared with adjudicated combined pre- and postcapillary (Cpc) PH related to heart failure with preserved ejection fraction (HFpEF). Participants underwent dynamic right heart catheterization and metabolomics. Findings were validated in 3 independent cohorts with adjudicated group 1 PH (validation cohorts 1 and 2 with exercise right heart catheterization and validation cohort 3 with resting right heart catheterization). RESULTS: Of 325 patients with group 1 PH (73% women, mean age 53.0±14.3 years), 15% (n=48) had high PAWP. Group 1 PH+high PAWP demonstrated greater obesity, left ventricular hypertrophy ( P <0.0002), left ventricular strain impairment ( P <0.0001), and decreased left ventricular compliance ( P <0.0001) compared with group 1 PH+normal PAWP, with changes comparable to Cpc-PH HFpEF (n=75). Compared with Cpc-PH HFpEF, left atrial function was better in group 1 PH+high PAWP with lower PAWP V wave, higher left atrial compliance, and left atrial ejection fraction ( P <0.0001 for all). Metabolomics demonstrated little difference between group 1 PH with high versus normal PAWP but large differences between group 1 PH+high PAWP versus Cpc-PH HFpEF (100 metabolites altered at false discovery rate P <0.05). Elevated PAWP was also observed in 18% of group 1 PH in the validation cohort 1 (n=402), with exercise PAWP response intermediately abnormal in group 1 PH+high PAWP relative to Cpc-PH HFpEF and group 1 PH+normal PAWP (interaction P <0.0001). Elevated PAWP was similarly observed in 22% and 19% of group 1 PH in validation cohorts 2 (n=55) and 3 (n=787), respectively. CONCLUSIONS: Approximately 1 in 5 adjudicated patients with group 1 PH has elevation in resting PAWP despite severe pulmonary vascular dysfunction and metabolomics consistent with traditionally defined group 1 PH. Despite resting PAWP elevation, these patients with group 1 PH were metabolomically and biologically distinct from Cpc PH HFpEF, with better left atrial function and diastolic reserve during exercise. These data emphasize the limitations of using resting PAWP alone to separate group 1 PH from HFpEF and call for development of more integrated clinical diagnostic criteria.

Abstract Aims Echo-derived left atrial (LA) stiffness index improves prognostication in patients with heart failure preserved ejection fraction but has not been studied in adults with repaired coarctation of aorta (COA). We hypothesized that, among adults with COA, those with high LA stiffness index would have worse disease severity indices [peak VO2, NT-proBNP, and right ventricular to pulmonary artery (RV-PA) coupling], heart failure hospitalization, and all-cause mortality. Methods and results LA stiffness index was estimated using the baseline echocardiogram as the quotient of septal E/e′ and LA reservoir strain (E/e′/LARS). Using the median septal LA stiffness index as the cut-off, patients were divided into high LA stiffness index (LA stiffness index &gt;0.28) vs. low LA stiffness index groups (LA suggests index ≤0.28). The study comprised of 729 patients [age 36 ± 16 years; males 437 (60%)]. LA stiffness index correlated with RV-PA coupling (r = −0.56, P &lt; 0.001), NT-proBNP (r = 0.62, P &lt; 0.001), and predicted peak VO2 (r = −0.51, P &lt; 0.001). High LA stiffness index was associated with heart failure hospitalization (adjusted HR 3.17, 95% confidence interval (CI) 1.84–7.36, P = 0.007) and all-cause mortality (adjusted HR 2.81, 95% CI 1.28–12.32, P = 0.005). LA stiffness index had superior prognostic performance for predicting 5-year risk of heart failure hospitalization (AUC 0.803, 95% CI 0.756–0.849, P &lt; 0.001) and all-cause mortality (AUC 0.786, 95% CI 0.742–08.30, P &lt; 0.001) compared with conventional echocardiographic indices of left heart diastolic function. Conclusion LA stiffness index improves prognostication in adults with COA and can potentially be used to guide timing of intervention or monitor response to therapy.

Background Patients with single-ventricle physiology are often palliated with the Fontan operation, which may involve the creation of a fenestration. We aimed to evaluate differences in cardiopulmonary exercise test (CPET) performance between patients with fenestrated and non-fenestrated Fontan circulation. Methods Patients with a Fontan circulation referred to CPET between 2006 and 2024 were included and were categorised based on their fenestration status at the time of CPET. Logistic regression analyses were performed to assess the impact of fenestration on peak oxygen consumption (VO 2 ), and Cox proportional hazard to evaluate the impact of fenestration on cardiovascular outcomes (death, heart transplant and Fontan-related hospitalisation). Results Of the 184 patients, 141 were classified as non-fenestrated and 43 as fenestrated. The minute ventilation-carbon dioxide production (V E /VCO 2 slope) was higher in the fenestrated (36.9±7.9) versus (33.2±6.2; p=0.009) in the non-fenestrated group. There was no significant difference in predicted VO 2 between groups (non-fenestrated 51.9%±14.4 vs 51.3%±15.6; p=0.7). Resting oxygen saturation was higher in the non-fenestrated group (93%±4.7 compared with fenestrated group 90.1%±5; p<0.001). Fontan fenestration was not significantly associated with the composite outcome; older patient age at the time of the CPET, cirrhosis and ventricular ejection fraction <40% were significantly associated with higher risk, while higher resting systolic blood pressure, left ventricular morphology and higher predicted peak VO 2 were protective. Conclusions The increased hypoxia and reduced ventilatory efficiency associated with Fontan fenestration offset any potential benefits, resulting in similar exercise performance between the groups. Fontan fenestration was not significantly associated with cardiovascular outcomes.

Abstract Background and Aims Decrease in pulmonary vascular resistance (PVR) during exercise confers favourable prognosis in biventricular physiology, but its role in Fontan circulation remains unknown. This study aimed to evaluate the prognostic value of PVR index (PVRI) response to exercise in adults post-Fontan palliation. Methods Retrospective cohort of 88 adults (age ≥18 years) post-Fontan undergoing exercise (supine cycling) cardiac catheterization. Patients were categorized into absence (n = 23) or presence (n = 65) of exercise-induced reduction in PVRI. The clinical endpoint was a composite of death or transplantation. Results Age at catheterization was 32.2 ± 8.8 years, and 45.5% were female. Resting and exercise PVRI were 1.9 ± 0.9 and 1.2 (interquartile range [IQR] 0.8–2.1) WU·m2, respectively. Clinical, biochemical and echocardiographic parameters were not associated with PVRI response to exercise. During a follow-up of 2.2 ± 1.4 (IQR 1.2–2.6) years, resting PVRI was not associated with the clinical endpoint (hazard ratio [HR] 0.95 per WU·m2, 95% confidence interval [CI] 0.52–1.74; P = 0.86), whereas exercise PVRI was (HR 2.15 per WU·m2, 95% CI 1.24–3.73; P = .007). Exercise PVRI remained predictive of outcomes after adjusting for exercise pulmonary artery wedge pressure (HR 2.08 per WU·m2, 95% CI 1.19–3.62; P = .01) or clinical risk factors individually. Two-year event-free survival was lower in the no PVRI reduction than in the reduction group (67% vs 95%; P &lt; .001). Conclusions In adults post-Fontan, PVRI response to exercise is a robust predictor of clinical outcomes and offers additive prognostic information beyond resting invasive haemodynamic data and clinical risk factors, underscoring the importance of invasive exercise testing in this population.

Background Exercise cardiac catheterization is the gold standard for diagnosing diastolic dysfunction and impaired pulmonary reserve in patients with Fontan circulation. The diagnostic value of noninvasive parameters is unclear. Methods Patients who underwent simultaneous exercise hemodynamic evaluation and peripheral venous pressure (PVP) measurement were included. Echocardiographic surrogates for ventricular filling pressure were compared with invasive measures. Diastolic dysfunction was defined invasively as either resting pulmonary artery wedge pressure ≥12 mm Hg or exercise pulmonary artery wedge pressure >20 mm Hg. Results Twenty‐nine patients were included. Age at catheterization was 34±9 years. Atrioventricular valve systole‐to‐diastole duration ratio (S/D) and resting PVP were significant predictors of resting pulmonary artery wedge pressure (S/D: β=0.71 per 0.1 S/D [95% CI, 0.16–1.25]; P =0.01; PVP: β=0.68 per mm Hg [95% CI, 0.41–0.96]; P <0.001). By contrast, resting PVP was a predictor of diastolic dysfunction, whereas S/D was not. Based on these data, we proposed a 2‐tier assessment algorithm with the first tier considering resting PVP ≤15 mm Hg and S/D ≤1.1 and the second tier considering exercise PVP ≤25 mm Hg in those with 1 elevated resting parameter. This algorithm showed a positive predictive value of 88% (95% CI, 47%–100%), a negative predictive value of 90% (95% CI, 70%–99%), a sensitivity of 78% (95% CI, 40%–97%), and a specificity of 95% (95% CI, 75%–100%). Exercise PVP indexed to peak oxygen consumption also predicted invasively measured exercise pulmonary vascular resistance index (β=0.36 WU·m 2 per mm Hg/100 mL per min [95% CI, 0.08–0.64]; P =0.01). Conclusions This study presents a simple, noninvasive approach for evaluating diastolic function and pulmonary vascular reserve in patients with a Fontan circulation.

Abstract Aims The effects of obesity on Fontan haemodynamics are poorly understood. Accordingly, we assessed its impact on exercise invasive haemodynamics and exercise capacity. Methods and results Seventy-seven adults post-Fontan undergoing exercise cardiac catheterization (supine cycle protocol) were retrospectively identified using an institutional database and categorized according to the presence of obesity [body mass index (BMI) &gt; 30 kg/m2] and overweight/normal BMI (BMI ≤ 30 kg/m2). There were 18 individuals with obesity (BMI 36.4 ± 3 kg/m2) and 59 with overweight/normal BMI (BMI 24.1 ± 3.6 kg/m2). Peak oxygen consumption (VO2) on non-invasive cardiopulmonary exercise testing was lower in patients with obesity (15.6 ± 3.5 vs. 19.6 ± 5.8 mL/kg/min, P = 0.04). At rest, systemic flow (Qs) [7.0 (4.8; 8.3) vs. 4.8 (3.9; 5.8) L/min, P = 0.001], pulmonary artery (PA) pressure (16.3 ± 3.5 vs. 13.1 ± 3.5 mmHg, P = 0.002), and PA wedge pressure (PAWP) (11.7 ± 4.4 vs. 8.9 ± 3.1 mmHg, P = 0.01) were higher, while arterial O2 saturation was lower [89.5% (86.5; 92.3) vs. 93% (90; 95)] in obesity compared with overweight/normal BMI. Similarly, patients with obesity had higher exercise PA pressure (29.7 ± 6.5 vs. 24.7 ± 6.8 mmHg, P = 0.01) and PAWP (23.0 ± 6.5 vs. 19.8 ± 7.3 mmHg, P = 0.047), but lower arterial O2 saturation [82.4 ± 7.0% vs. 89% (85; 92), P = 0.003]. Conclusion Adults post-Fontan with obesity have worse aerobic capacity, increased Qs, higher filling pressures, and decreased arterial O2 saturation compared with those with overweight/normal BMI, both at rest and during exercise, mirroring the findings observed in the obesity phenotype of heart failure with preserved ejection fraction. Whether treating obesity and its cardiometabolic sequelae in Fontan patients will improve haemodynamics and outcomes requires further study.

BACKGROUND: There are limited data about changes in cardiac function (cardiac reverse remodeling) and heart failure indices after transcatheter tricuspid valve-in-valve replacement (TT-VIVR). The purpose of this study was to evaluate cardiac reverse remodeling and temporal changes in heart failure indices after TT-VIVR in adults with congenital heart disease. METHODS: Retrospective cohort study of adults with congenital heart disease that underwent TT-VIVR and had >6 months of follow-up (January 1, 2011, to April 30, 2023). Echocardiographic indices of cardiac remodeling and heart failure indices (New York Heart Association class, NT-proBNP (N-terminal pro-brain natriuretic peptide), glomerular filtration rate, and model for end-stage liver disease excluding international normalized ratio score) were assessed preintervention and at 1-, 3-, and 5-year postintervention. RESULTS: Of 39 patients (age 39 [32–46] years), 14 (36%) and 25 (64%) received Melody valve and Sapien valve prosthesis, respectively. At 1-year post-TT-VIVR, there was a temporal improvement in right atrial reservoir strain (17±8% versus 22±8%, P <0.001), right atrial volume (81 [59–108] versus 63 [48–82] mL/m 2 , P <0.001), right atrial pressure (12±4% versus 6±4%, P <0.001), and right ventricular global longitudinal strain (−15±7% versus −20±7%, P <0.001). Similarly, there was a temporal improvement in NT-proBNP, glomerular filtration rate, model for end-stage liver disease excluding international normalized ratio score, and New York Heart Association class. The temporal improvements in heart failure indices and valve function were maintained at 3- and 5-year post-TT-VIVR. CONCLUSIONS: Considering the significant mortality risk associated with reoperations for tricuspid valve replacement, these data suggest favorable outcomes after TT-VIVR, and support TT-VIVR as a viable alternative to surgical tricuspid valve replacement, especially in high-risk patients.