Ali, Ahmed E.

Key Points Genetic testing of individuals suspected of monogenic urinary stone disease resolved 34% of families with 22 different genes detected. Resolved individuals had a lower baseline and last visit eGFR and earlier age of stone presentation than the unresolved group. Specific phenotypes and younger diagnostic age were associated with a monogenic cause, allowing refinement of future screenings. Background Urinary stone disease with a clear genetic cause, monogenic stone disease (MSD), is increasingly recognized as a significant proportion of the total population. When MSD is suspected, genetic testing provides a firm diagnosis that can alter management and treatment. Here, we present testing results from a large cohort with suspected MSD. Methods Patients with features suggestive of MSD (early onset, family history, frequent stones, nephrocalcinosis [NC], and/or CKD) were recruited by the Rare Kidney Stone Consortium and genotyped for up to 160 known or candidate MSD genes via a targeted massively parallel sequencing panel. We compared clinical and biochemical features between genetically resolved MSD and unresolved individuals. Results Of 426 families (657 patients) enrolled, 145 (34%) were resolved with identified disease associated variants in 22 known MSD genes. Ninety-nine families were biallelic, 37 monoallelic, and two digenic. An additional 21 of the 231 screened family members were resolved. Genes identified in ten or more families include the following: AGXT , HOGA1 , SLC34A3 , CYP24A1 , SLC3A1 , and CLCN5 . Compared with the unresolved group, MSD probands had a lower baseline and last visit eGFR, earlier age of stone presentation, and more stone events and procedures/year of life. The resolve rate was higher in those <16 years, and NC was seen earlier in the MSD group. Overall, NC was a risk factor for lower eGFR. Among the specific disorders, patients with primary hyperoxaluria had the earliest age of stone and NC diagnosis, and as expected, the highest urinary oxalate level. Conclusions Our study emphasizes the value of selecting patients enriched for factors associated with MSD, and comprehensive genetic testing to achieve a high yield of genetic diagnoses. Significant clinical and biochemical characteristics of patients with MSD were defined. A definitive MSD diagnosis facilitates individualized management and strategies to delay disease progression in probands and affected family members.

Abstract Aims Systemic ventricular (SV) strain imaging improves early detection of systolic dysfunction in patients with congenital heart disease and biventricular circulation. However, its role for risk stratification in the Fontan population has not been systematically studied. We hypothesized that among Fontan patients with normal SV ejection fraction (Echo_EF) at baseline, those with reduced SV longitudinal strain (Echo_LS) would have a higher risk of progressive SV systolic dysfunction, greater neurohormonal activation, and cardiovascular events (heart failure hospitalization/death/transplant) during follow-up. Methods and results We studied adults with Fontan palliation and normal SV systolic function (Echo_EF &gt;50%) at baseline who underwent follow-up echocardiogram &gt;36 months after the baseline echocardiogram. Echo_LS was assessed from the apical 4-chamber window using speckle tracking echocardiography. Patients were divided into reduced vs. normal Echo_LS groups, using −18% as the cut-off point. Echo_LS, Echo_EF, and NT-proBNP were assessed at baseline and follow-up encounters. Of 272 patients (age, 28 ± 8 years), 98 (36%) and 174 (64%) had reduced vs. normal Echo_LS. The reduced_Echo_LS group had progressive SV systolic dysfunction [worse temporal decline in Echo_EF (relative_Δ_Echo_EF −12.8% vs. −2.1%, P &lt; 0.001)], and higher prevalence of new-onset SV systolic dysfunction [30% (29/98) vs. 8% (13/174), P &lt; 0.001]. The reduced Echo_LS group also had greater neurohormonal activation [relative Δ_ NT-proBNP 36 (95%CI, 27–43) % vs. 17 (95%CI, 11–23) %, P &lt; 0.001], and higher risk of cardiovascular events (adjusted hazard ratio 1.84, P = 0.009). Conclusion Echo_LS improves risk stratification in Fontan patients with normal Echo_EF and may provide an opportunity for early interventions to improve outcomes.

Background Atrial dysfunction is a risk factor for atrial arrhythmia and can be detected by atrial strain imaging in patients with biventricular circulation. However, the role of atrial strain imaging for risk stratification of atrial arrhythmia in patients with Fontan palliation has not been studied, despite the high prevalence and prognostic implications of atrial arrhythmia in this population. We hypothesized that pulmonary venous atrial strain was associated with new‐onset and recurrent atrial arrhythmia in Fontan physiology. Method and Results This is a retrospective study of adults with Fontan palliation and no prior history of atrial arrhythmia who underwent atrial strain imaging by speckle tracking echocardiography (2003–2023). New‐onset and recurrent atrial arrhythmias were ascertained from baseline encounter to last follow‐up. Of 404 patients, atrial reservoir strain assessment was feasible in 329 patients (81%), with modest intra‐ and interobserver agreement. The median atrial reservoir strain was 18% (interquartile range, 13%–24%), and atrial dysfunction (atrial reservoir strain <28%) was present in 294 (89%). Atrial reservoir strain <15% was associated with new‐onset atrial arrhythmia (adjusted hazard ratio [HR], 1.59 [95% CI, 1.09–2.34]; P =0.009), and recurrent atrial arrhythmia (adjusted HR, 2.01 [95% CI, 1.06–3.93]; P =0.003). Rhythm control therapy was associated with lower risk of recurrence compared with rate control therapy (adjusted HR, 0.92 [95% CI, 0.86–0.98]; P =0.003). Conclusions Atrial dysfunction was common and was associated with new‐onset and recurrent atrial arrhythmias. The higher prevalence of atrial arrhythmias in patients with reduced atrial strain and the apparent protective effect of rhythm control therapy suggest that rhythm control therapy may be the preferred treatment in patients with reduced atrial strain.

BACKGROUND: Patients with Fontan palliation have reduced aerobic capacity because of impaired cardiac, pulmonary, and skeletal muscle function. However, the assessment of aerobic capacity in this population still relies on comparisons with people without cardiovascular disease rather than comparison with the expected aerobic capacity of other Fontan patients. The purpose of this study was to determine the expected aerobic capacity of adults with Fontan palliation. METHODS: Adults with Fontan palliation who underwent a cardiopulmonary exercise test at Mayo Clinic (2003–2023) were stratified into quartiles based on the predicted peak oxygen consumption (VO 2 ). We assessed the correlates of predicted peak VO 2 and the relationship between predicted peak VO 2 quartiles and cardiovascular outcomes (death/transplant). RESULTS: Of 323 patients (age, 29±9 years; 177 [55%] men), the median peak VO 2 was 19.1 (15.2–23.9) mL/kg per minute, and this corresponds to a predicted peak VO 2 of 51% (range, 19–88; interquartile range, 41–62). After multivariable adjustments, the correlates of predicted peak VO 2 were body mass index (β±SE, −2.61±0.95; 2.61% decrease in predicted peak VO 2 per 5 kg/m 2 increase in body mass index; P =0.009), systemic saturation (β±SE, 3.65±0.85; 3.65% increase in predicted peak VO 2 per 5% increase in oxygen saturation; P <0.001), and Fontan pressure (β±SE, −1.24±0.22; 1.24% decrease in predicted peak VO 2 per 1 mm Hg increase in Fontan pressures; P <0.001). There was a 47% increase in the risk for death/transplant from a higher predicted peak VO 2 quartile to the next lower quartile (adjusted hazard ratio, 1.47 [95% CI, 1.09–2.05]; P =0.01). CONCLUSIONS: The results of the current study would help calibrate the interpretation of exercise test data in adults with Fontan palliation and improve risk stratification in this population. It also underscores the need to maintain normal Fontan hemodynamics and body weight, which are important determinants of aerobic capacity.

Background: Patients with Fontan palliation have reduced aerobic capacity because of impaired cardiac, pulmonary, and skeletal muscle function. However, the assessment of aerobic capacity in this population still relies on comparisons with people without cardiovascular disease, rather than comparison with the expected aerobic capacity of other Fontan patients. The purpose of this study was to determine the expected aerobic capacity of adults with Fontan palliation. Method: Adults with Fontan palliation who underwent cardiopulmonary exercise test at Mayo Clinic (2003-2023) were stratified into quartiles based on the predicted peak VO 2 . We assessed the correlates of predicted peak VO 2 , and the relationship between predicted peak VO 2 quartiles and cardiovascular outcomes (death/transplant). Results: Of 323 patients (age 29±9 years; 177 [55%] men), the median peak VO2 was 19.1 (15.2 - 23.9) ml/kg/min, and this corresponds to a predicted peak VO 2 of 51% (range 19 -88; interquartile range 41 - 62). The correlates of higher predicted peak VO 2 were smaller body mass index, higher systemic saturation, and lower Fontan pressures. The top, 2 nd ,3 rd , and bottom quartile of predicted peak VO 2 corresponds to predicted peak VO 2 of 63-88%, 51-62%, 41-50%, and 19-40%, respectively. Using the top quartile as the reference, the 3 rd quartile (HR 1.13, 95% CI 1.03-1.28, p=0.02), and 4 th quartile were associated with a higher risk of death/transplant (HR 1.32, 95% CI 1.16-1.69, p<0.001). Conclusions: The results of the current study would help calibrate the interpretation of exercise test data in adults with Fontan palliation and improve risk stratification in this population.

Background: We hypothesized that patients with coarctation of aorta (COA) and obesity would have more advanced cardiovascular remodeling and impaired aerobic capacity compared to COA patients without obesity. The purpose of this study was to assess the relationship between obesity, cardiovascular remodeling, and aerobic capacity in adults with repaired COA. Methods: The study comprised of 3 groups: (1) Obese COA group (n=177) (COA patients with body mass index [BMI] >30 kg/m2); (2) Non-obese COA group (n=572) (COA patients with BMI ≤30 kg/m2); (3) Control group (n=59) (subjects without structural heart disease and BMI ≤30 kg/m2). Cardiovascular remodeling was assessed using the following indices: (1) Arterial stiffness - total arterial compliance index (TACI). (2) Left ventricular hypertrophy - LV mass (LVM) and relative wall thickness (RWT). (3) LV diastolic function - Doppler-derived estimated LV end-diastolic pressure (LVEDP) and Tau. (4) Right ventricular-pulmonary artery coupling - RV free wall strain and right ventricle systolic pressure (RVFW/RVSP). Aerobic capacity was assessed using predicted peak oxygen consumption (VO2). Results: The obese COA group had higher LVM, RWT, LVEDP, and Tau, well as lower RVFWS/RVSP, TACI and peak VO2 compared to non-obese COA group and controls. There was a correlation between BMI and LVM (r=0.39, p<0.001), RWT (r=0.47, p<0.001), estimated LVEDP (r=0.43, p<0.001), tau (r=0.22, p=0.008), RVFWS/RVSP (r=- 0.24, p<0.001), and predicted peak VO2 (r= -0.48, p<0.001). Conclusions: These findings underscore the cardiovascular implications of obesity in the setting of COA, and provide opportunities for interventions to address obesity and improve outcomes in the COA population.

Background The purpose of this study was to describe the correlates and outcomes in adults with unrepaired partial anomalous pulmonary venous return and intact atrial septum (PAPVR‐IAS). Methods and Results We identified adults with PAPVR‐IAS who received care at the Mayo Clinic, while those with unrepaired PAPVR‐IAS comprised the reference group. Clinical indices (New York Heart Association class, peak oxygen consumption, and NT‐proBNP [N‐terminal pro‐B‐type natriuretic peptide]) and echo‐derived right heart indices (right atrial [RA] volume, RA reservoir strain, right ventricular [RV] free wall strain, RV end‐diastolic area, and RV systolic pressure) were assessed at baseline and 3‐year and 5‐year follow‐up. There were 80 patients and 38 patients with unrepaired versus repaired PAPVR‐IAS, respectively. The clinical predictors of surgical repair were the number of anomalous veins, RA volume, and RV end‐diastolic area. The PAPVR‐IAS risk score, derived from these clinical predictors, was associated with surgical repair (adjusted odds ratio, 1.37 [95% CI, 1.24–1.65] per unit increase in risk score; area under the curve, 0.742). Among patients with unrepaired PAPVR‐IAS with 3‐year (n=73) and 5‐year follow‐up (n=36), there was no temporal change in clinical indices (New York Heart Association class, predicted peak oxygen consumption, and NT‐proBNP) and right heart indices (RA volume index, RA reservoir strain, RV end‐diastolic area index, RV free wall strain, and RV systolic pressure). Conclusions The PAPVR‐IAS risk score can be used to assess the odds of requiring surgical repair. Furthermore, there was no temporal deterioration in clinical and right heart indices during follow‐up in adults with unrepaired PAPVR‐IAS.

Key Points Common kidney stones are unlikely to be an independent and direct cause of CKD in the general population. CKD may protect against kidney stones because of changes in key urinary factors critical for stone formation. Background Kidney stones and CKD are common disorders with a substantial interaction. Although observational studies have suggested a potential for enhanced CKD risk after prior kidney stones, the exact relationship remains ambiguous. Methods Shared comorbidities between two diseases were identified using unbiased screening. Genome-wide association study summary statistics were obtained from the UK Biobank (UKBB), FinnGen, and CKDGen, followed by genetic association analyses across various traits. Bidirectional Mendelian randomization (MR) analyses were performed to define causal links, complemented by multivariable MR that included the shared comorbidities including hypertension, diabetes, and obesity. Observational analyses were undertaken using cohorts from the Mayo Clinic and a UKBB subset. Results Despite identifying a total of 123 conditions as shared comorbidities, there was no significant genetic correlation between kidney stones and CKD. Unadjusted MR analysis revealed no significant association between kidney stones and CKD risk (UKBB [exposure]/FinnGen [outcome]: odds ratio [OR]=0.97, 95% confidence interval [CI], 0.88 to 1.06; FinnGen/UKBB: OR=1.17, 95% CI, 0.98 to 1.39). Kidney stones did significantly associate with a higher urinary albumin-creatinine ratio ( β =0.014, 95% CI, 0.002 to –0.025), but this association disappeared in the multivariable MR model ( β =0.009, 95% CI, −0.003 to 0.020). Furthermore, in a cross-sectional analysis limited to the UKBB cohort, a robust regression model did not detect an independent association between kidney stones and urinary albumin-creatinine ratio ( β =0.16, 95% CI, −0.04 to 0.35) or eGFR ( β =0.10, 95% CI, −0.07 to 0.28). Conversely, CKD associated with a diminished risk of kidney stones in multivariable MR models (UKBB/FinnGen: OR=0.77, 95% CI, 0.69 to 0.87; FinnGen/UKBB: OR=0.73, 95% CI, 0.66 to 0.81). Furthermore, in the Mayo Clinic cohort with available urinary biochemistries, lower eGFR was associated with lower urinary calcium excretion and urinary calcium oxalate/phosphate supersaturation. Conclusions In this study, kidney stones were not independently associated with CKD. Conversely, CKD was associated with a lower risk of calcium kidney stones likely via changes in key urinary traits, including lower calcium excretion.

Aims There are similarities in the pathogenesis of cardiac remodelling and dysfunction in heart failure with preserved ejection fraction (HFpEF) and coarctation of aorta (COA). We hypothesized that clinical HFpEF would be highly prevalent in adults with COA, and that the presence of HFpEF would increase the risk of mortality in this population. The aim of this study was to define the clinical features, haemodynamics, and prognostic implications of HFpEF in COA. Methods and results Consecutive adults with repaired COA that underwent right heart catheterization were identified retrospectively. HFpEF was defined as heart failure symptoms (exertional dyspnoea or fatigue), preserved left ventricular ejection fraction ≥50%, and pulmonary artery wedge pressure at rest >15 mmHg. Of 99 COA patients, 32 (32%) had HFpEF. The correlates of HFpEF were obesity (adjusted odds ratio [OR] 4.15, 95% confidence interval [CI] 1.31–13.2), atrial fibrillation (adjusted OR 3.13, 95% CI 1.00–10.7), total arterial compliance index (adjusted OR 0.12, 95% CI 0.06–0.41 per 1 ml/mmHg*m 2 ), and pulmonary artery compliance index (adjusted OR 0.36, 95% CI 0.15–0.56 per 1 ml/mmHg*m 2 ). Of 99 patients, 24 (24%) died and 5 (5%) underwent heart transplant. The 10‐year cumulative incidence of death/transplant was higher in COA patients with HFpEF compared with patients without HFpEF (39% vs. 12%, p = 0.001). The presence of HFpEF was associated with increased risk of death/transplant (adjusted hazard ratio 1.68, 95% CI 1.16–3.11). Conclusions Heart failure with preserved ejection fraction is common in adults with COA and is associated with greater risk of death/transplant, emphasizing a pressing need for interventions to prevent and treat HFpEF in COA.