Mohamad Al-Otaibi

Temporal changes in liver stiffness after Fontan operation: Results of serial magnetic resonance elastography

BACKGROUNDnThe relationship between temporal progression of magnetic resonance elastography derived liver stiffness (MRE-LS) and progression of Fontan associated liver disease (FALD) is unknown. To assess this relationship, we hypothesized that progression of MRE-LS correlated with progression FALD severity and clinical outcomes.nnnMETHODSnRetrospective review of Fontan patients who had >1 liver MRE, 2010-2016. Annual change in MRE-LS was the quotient of the difference between baseline and subsequent MRE-LS, and the interval between scans.nnnRESULTSn22 patients were enrolled; median age 29(19-38) years, 14 (64%) males and 10 (46%) with atriopulmonary Fontan. Baseline and subsequent MRE-LS values were 5.4u202f±u202f1.1 kPa and 5.8u202f±u202f0.9 kPa for clarity, interval between scans was 25u202f±u202f5u202fmonths, and annual change in MRE-LS was 0.3u202f±u202f0.2u202fkPa. Temporal change in MRE-LS correlated with temporal changes in model for end-stage liver disease (MELD) score (ru202f=u202f0.84, pu202f<u202f0.001) and model for end-stage liver disease excluding international normalized ratio (MELD-XI) score (ru202f=u202f0.75, pu202f=u202f0.001). The study cohort was divided into 2 groups using the mean annual change in MRE-LS as the cut point. Groups A and B comprised of patients with annual increase in MRE-LS ≥0.3u202fkPa (nu202f=u202f6) and <0.3u202fkPa (nu202f=u202f16) respectively. Composite adverse event endpoint (death, heart-liver transplant listing, palliative care, hospitalization, paracentesis) was more common in Group A (4 of 6, 67%) compared to Group B (3 of 16, 19%), pu202f=u202f0.13 although this did not reach statistical significance due to small sample size.nnnCONCLUSIONSnProgression of MRE-LS correlated with clinical deterioration as measured by worsening liver disease severity scores and the occurrence of adverse events.

Outcomes of Hospitalization in Adults with Fontan Palliation: The Mayo Clinic Experience

Background The outcomes of hospitalization in the Fontan population have not been specifically studied. The purpose of this study was to describe outcomes of hospitalization (frequency and indications for hospitalization, and in‐hospital mortality) in this population and to determine how these outcomes differ from those of other adults with congenital heart disease (CHD). Methods This was a retrospective study of adult Fontan patients hospitalized at Mayo Clinic Rochester in 1990‐2015. We selected age‐ and gender‐matched control group of patients with repaired CHD and biventricular circulation hospitalized within the study period. Results A total of 367 Fontan patients (age 31 ± 7 years and 259 [71%] with atriopulmonary Fontan) had 853 hospital admissions in 4 years (58 hospitalizations per 100 patient‐years). The most common indications were arrhythmia (n = 188, 22%), heart failure (n = 169, 20%), and cardiac surgery (n = 133, 16%). Overall in‐hospital mortality was 4% (n = 38), and the highest in‐hospital mortality occurred in patients hospitalized for cardiac surgery (n = 15, 11%) and heart failure (n = 13, 8%). In comparison to the repaired CHD and biventricular circulation group, the Fontan group had more frequent hospitalizations (22 vs 58 per 100 patient‐years, P < .001) and higher overall in‐hospital mortality (1% vs 5%, P < .001), mortality after cardiac surgery (2% vs 11%, P = .01), and mortality for heart failure–related hospitalizations (2% vs 8%, P = .04). Conclusions Adults with Fontan palliation had more frequent hospitalization and in‐hospital mortality compared to the rest of the CHD population. Arrhythmia and heart failure were the most common indications for hospitalization. Perhaps optimal management of heart failure and arrhythmia may improve outcomes in this population.

Venous congestion and pulmonary vascular function in Fontan circulation: Implications for prognosis and treatment

BACKGROUNDnElevation in central venous pressure (CVP) plays a fundamental pathophysiologic role in Fontan circulation. Because there is no sub-pulmonary ventricle in this system, CVP also provides the driving force for pulmonary blood flow. We hypothesized that this would make Fontan patients more susceptible to even low-level elevation in pulmonary vascular resistance index (PVRI), resulting in greater systemic venous congestion and adverse outcomes.nnnMETHODSnAdult Fontan patients and controls without congenital heart disease undergoing clinical evaluation that included cardiac catheterization and echocardiography were examined retrospectively. Outcomes including all-cause mortality and the development of Fontan associated diseases (FAD, defined as protein losing enteropathy, cirrhosis, heart failure hospitalization, arrhythmia, or thromboembolism) were assessed from longitudinal assessment.nnnRESULTSnAs compared to controls (nu202f=u202f82), Fontan patients (nu202f=u202f164) were younger (36 vs 45u202fyears, pu202f<u202f0.001), more likely to be on anticoagulation or antiplatelet therapy, and more likely to have atrial arrhythmia or cirrhosis. There was a strong correlation between CVP and PVRI in the Fontan group (ru202f=u202f0.79, pu202f<u202f0.001), but there was no such relationship in controls. Elevated PVRI identified patients at increased risk for FAD (HR 1.92, 95% CI 1.39-2.41, pu202f=u202f0.01), and composite endpoint of FAD and/or death (HR 1.89, 95% CI 1.32-2.53, pu202f=u202f0.01) per 1u202fWU∗m2 increment.nnnCONCLUSIONSnSystemic venous congestion, which is the primary factor in the pathogenesis of FAD and death, is related to even low-level abnormalities in pulmonary vascular function. Multicenter studies are needed to determine whether interventions targeting pulmonary vascular structure and function can improve outcomes in the Fontan population.

Progressive right ventricular enlargement due to pulmonary regurgitation: Clinical characteristics of a “low-risk” group

Background: The optimal interval between serial cardiac magnetic resonance imaging (CMRI) scans for monitoring right ventricular (RV) enlargement in the setting of severe pulmonic valve regurgitation (PR) is unknown. The purposes of this study were to (1) determine the annual change in RV volume on serial CMRI scans and (2) identify the risk factors for rapid progression of RV enlargement. Methods: A retrospective study of adults with postintervention native valve PR and ≥2 CMRI scans at Mayo Clinic Rochester from 2000 to 2015 was conducted. Rapid progression of RV enlargement was defined as first upper quartile of annual increase in RV end‐diastolic volume index (RVEDVi) for the cohort. Results: Of the 63 patients (age, 36 ± 9 years) in the study, 43 (68%) had tetralogy of Fallot, whereas 20 (32%) had valvular pulmonic stenosis. Right ventricular outflow tract interventions that resulted in PR were balloon pulmonary valvuloplasty (n = 4; 7%), transannular patch repair (n = 30; 58%), and nontransannular patch repair (n = 18; 35%). Interval between baseline and second CMRI was 2 (1‐4) years. In comparison to baseline CMRI, RVEDVi increased from 130 (109‐141) to 135 (126‐155) mL/m2 and median annual change in RVEDVi was 3.1 (1.7‐5.9) mL/m2. Univariate risk factors for rapid progression of RV enlargement (annual increase in RVEDVi >6 mL/m2) were ≥moderate tricuspid regurgitation and RVEDVi >130 mL/m2. Among the 24 patients without these risk factors (low‐risk subgroup), RVEDVi increased by only 3 (0‐7) mL/m2 over 7 (5‐9) years. Conclusions: Patients with PR without RVEDVi >130 mL/m2 and/or ≥moderate tricuspid regurgitation represent a low‐risk subgroup that may be appropriate for clinical and echo follow‐up but may potentially require infrequent CMRI follow‐up.

Role of Doppler Echocardiography for Cardiac Output Assessment in Fontan Patients

Background To determine (1) correlation between Doppler stroke volume index (SVI) and cardiac magnetic resonance imaging (CMRI) SVI and (2) association between Doppler SVI and Fontan‐associated diseases (FAD) and Fontan failure. Methods Review of Fontan patients who underwent same‐day CMRI and transthoracic echocardiography (TTE), 2005 to 2015. We defined FAD as cardiac thrombus, protein‐losing enteropathy, arrhythmia, and hospitalization for heart failure. Fontan failure was defined as Fontan conversion or revision, heart transplantation or listing, or death. Results Fifty‐three patients with systemic left ventricle (LV) underwent 86 sets of TTE/CMRI. Mean (SD) age 31 (6) years. SVI (45 [16] vs 42 [13] mL/m2), CI (3.0 [1.1] vs 2.8 [0.8] L min−1 m−2), and ejection fraction (53 [4]% vs 51 [5]%) were similar for both modalities (P > .05 for all). Doppler SVI correlated with CMRI (r = 0.68; P < .001). Sixteen patients had cirrhosis, and these patients had a higher CI (3.9 [0.9] vs 2.8 [1.0] L min−1 m−2; P < .01). Among the 37 patients without cirrhosis, Doppler SVI <39 mL/m2 was associated with FAD (odds ratio [OR], 2.11; 95% confidence limit, 1.26–3.14; P = .02); Fontan failure was more common in patients with CI was <2.5 L min−1 m−2 (3/9 [33%] vs 0/28 [0%], P = .01). Another 11 patients with systemic right ventricle (RV) underwent 17 sets of TTE/CMRI, mean (SD) age 17 (3) years, and CMRI SVI also correlated with Doppler SVI (r = 0.75; P < .001). Conclusion Doppler SVI correlated with CMRI SVI in patients with systemic LV and systemic RV. The association between output measures (SVI and CI) and FAD were seen only in single LV patients (single RV patients not assessed for this outcome due to small numbers). An association between low Doppler CI and Fontan failure was suggested in a small number of single LV patients.

Invasive and noninvasive hemodynamic assessment in adults with Fontan palliation

BACKGROUND/OBJECTIVESnAlthough echocardiographic-Doppler cardiac index (CI) assessment is widely used to guide heart failure management in patients with biventricular circulation, this application has not been studied in the Fontan population. The objective of this study was to: (1) determine the correlation between Doppler and cardiac catheterization CI calculation; (2) determine the association between Doppler CI and the occurrence of Fontan failure.nnnMETHODSnRetrospective review of adult Fontan patients followed at Mayo Clinic Adult Congenital Heart Disease program, 1994-2015. Inclusion criteria were: systemic left ventricle and echocardiogram and cardiac catheterization performed within the same week. Fontan failure was defined as a composite of all-cause mortality, heart transplantation listing, and palliative care.nnnRESULTSn59 patients (age 29±6years; men 32[54%]) underwent 97 studies. Of the 59, 41[69%] had atriopulmonary Fontan and 12 (20%) had cirrhosis. Compared to patients without cirrhosis, patients with cirrhosis had higher Doppler CI (3.6±0.6 vs 2.8±0.4L/min∗m2, p=0.039); Fick CI (3.3 [2.5-3.7] vs 2.4 [1.6-3.1] L/min/m2, p=0.028); lower systemic vascular resistance (20±3 vs 25±4 WU∗m2, p=0.04). There was a positive correlation between Doppler and Fick CI (r=0.52; p<0.0001). Fontan failure occurred in 13 patients (22%) within 7.5±2.1years. In patients without cirrhosis, Fick CI and Doppler CI <2.5L/min/m2 were associated with Fontan failure (odds ratio [OR] 1.58, p=0.046) and (OR 1.43, p=0.051) respectively.nnnCONCLUSIONSnDoppler CI assessment in feasible in a selected group of Fontan patients and it is predictive of clinical outcomes. The application of this concept in systemic right ventricles deserves further research.