Joseph T. Poterucha

Bioprosthetic Valve Thrombosis Versus Structural Failure: Clinical and Echocardiographic Predictors.

BACKGROUND Bioprosthetic valve thrombosis (BPVT) is considered uncommon; this may be related to the fact that it is often unrecognized. Recent data suggest that BPVT responds to vitamin K antagonists, emphasizing the need for reliable diagnosis. OBJECTIVES This study sought to determine the diagnostic features of BPVT and to formulate a diagnostic model for BPVT. METHODS Cases of BPVT occurring between 1997 and 2013 were identified from the Mayo Clinic pathology database. Patients with BPVT were matched 1:2 for age, sex, and prosthesis position with patients whose valves were explanted for structural failure. We formulated a diagnostic model for BPVT using multivariate linear logistic regression and receiver operating characteristic. RESULTS Among 397 consecutive cases of explanted bioprostheses, there were 46 cases of BPVT (11.6%; aortic 29, mitral 9, tricuspid 7, pulmonary 1), mean age was 63 years, and 68% were male. Thirty (65%) cases occurred >12 months post-implantation; median bioprosthetic valve longevity was 24 months (cases) versus 108 months (controls) (p < 0.001). Independent predictors of BPVT were >50% increase in mean echo-Doppler gradient from baseline within 5 years (odds ratio [OR]: 12.7), paroxysmal atrial fibrillation (OR: 5.19), subtherapeutic international normalized ratio (OR: 7.37), increased cusp thickness (OR: 12.2), and abnormal cusp mobility (OR: 6.94). Presence of all 5 diagnostic features was predictive of BPVT with 76% sensitivity, 93% specificity, 85% positive predictive value, and 89% negative predictive value (p < 0.001). CONCLUSIONS BPVT is not uncommon and can occur several years after surgery. A combination of clinical and echocardiographic features can reliably diagnose BPVT.

Liver Disease in Patients After the Fontan Operation

We reviewed records of all patients with an initial Fontan operation or revision from 1973 to 2012 at our institution (n = 1,138); 195 patients had postoperative liver data available. Cirrhosis was identified by histopathology or characteristic findings on imaging with an associated diagnosis of cirrhosis by a hepatologist. Of 195 patients with biopsy or imaging, 10-, 20-, and 30-year freedom from cirrhosis was 99%, 94%, and 57%, respectively. There were 40 of 195 patients (21%) diagnosed with cirrhosis (mean age at Fontan 10.7 ± 8 years). On multivariate analysis, hypoplastic left heart syndrome was associated with increased risk of cirrhosis (n = 2 of 16, p = 0.0133), whereas preoperative sinus rhythm was protective (p = 0.009). Survival after diagnosis of cirrhosis was 57% and 35%, at 1, and 5 years, respectively. The cause of death was known for 9 patients (5 multiorgan failure, 2 liver failure, and 2 heart failure). In conclusion, there is an incremental occurrence of cirrhosis after the Fontan, which should be considered when designing follow-up protocols for patients after Fontan operation.

Magnetic Resonance Elastography. A Novel Technique for the Detection of Hepatic Fibrosis and Hepatocellular Carcinoma After the Fontan Operation

OBJECTIVE To evaluate the utility of magnetic resonance elastography (MRE) in screening patients for hepatic fibrosis, cirrhosis, and hepatocellular carcinoma after the Fontan operation. PATIENTS AND METHODS Hepatic MRE was performed in conjunction with cardiac magnetic resonance imaging in patients who had undergone a Fontan operation between 2010 and 2014. Liver stiffness was calculated using previously reported techniques. Comparisons to available clinical, laboratory, imaging, and histopathologic data were made. RESULTS Overall, 50 patients at a median age of 25 years (range, 21-33 years) who had undergone a Fontan operation were evaluated. The median interval between Fontan operation and MRE was 22 years (range, 16-26 years). The mean liver stiffness values were increased: 5.5 ± 1.4 kPa relative to normal participants. Liver stiffness directly correlated with liver biopsy-derived total fibrosis score, time since operation, mean Fontan pressure, γ-glutamyltransferase level, Model for End-Stage Liver Disease score, creatinine level, and pulmonary vascular resistance index. Liver stiffness was inversely correlated with cardiac index. All 3 participants with hepatic nodules exhibiting decreased contrast uptake on delayed postcontrast imaging and increased nodule stiffness had biopsy-proven hepatocellular carcinoma. CONCLUSION The association between hepatic stiffness and fibrosis scores, Model for End-Stage Liver Disease scores, and γ-glutamyltransferase level suggests that MRE may be useful in detecting (and possibly quantifying) hepatic cirrhosis in patients after the Fontan operation. The correlation between stiffness and post-Fontan time interval, mean Fontan pressure, pulmonary vascular resistance index, and reduced cardiac index suggests a role for long-term hepatic congestion in creating these hepatic abnormalities. Magnetic resonance elastography was useful in detecting abnormal nodules ultimately diagnosed as hepatocellular carcinoma. The relationship between stiffness with advanced fibrosis and hepatocellular carcinoma provides a strong argument for additional study and broader application of MRE in these patients.

Percutaneous Pulmonary Valve Implantation in a Native Outflow Tract: 3-Dimensional DynaCT Rotational Angiographic Reconstruction and 3-Dimensional Printed Model

A 15-year-old girl with D-transposition of the great arteries presented with combined neo-pulmonary stenosis and regurgitation following arterial switch operation as a neonate and neo-pulmonary valvectomy at 6 years of age. Echocardiography revealed right ventricular enlargement and severe neo-

Mixed aortic valve disease: midterm outcome and predictors of adverse events

AIMS The aim of this article is to determine freedom from adverse events (AE) defined as symptoms, aortic valve replacement (AVR), or death in the mixed aortic valve disease (MAVD) population. METHODS AND RESULTS We reviewed patients with moderate/severe MAVD followed at Mayo Clinic from 1994-2013. Only asymptomatic patients with normal ejection fraction and trileaflet aortic valve were included. Cox proportional-hazard models and Kaplan-Meier method were used. We identified 213 patients with moderate/severe MAVD; mean age was 69 years (±11) and 67% were males. An AE endpoint was reached in 172 patients, and 69% of these AEs occurred in moderate MAVD (peak velocity of 3-3.9 m/s). Mean follow-up was 10.1 ± 3 years, and mean time to AE was 2.9 ± 2.1 years. A mechanical prosthesis was implanted in 71/151 (47%), and 54/151 (36%) had concomitant coronary artery bypass grafting and/or aorta replacement during AVR. Early surgical mortality was 0.7%. Freedom from AE endpoint was 42% [confidence interval (CI) 39-45%] and 30% (CI 27-33%) at 3 and 5 years, respectively. Predictors of AE were peak aortic velocity [hazard ratio (HR) 2.73; CI 1.97-2.84, P < 0.0001] for every 1 m/s difference and having severe stenosis or severe regurgitation at presentation (HR 2.58; CI 2.01-4.44, P = 0.001). CONCLUSION Moderate MAVD had high rate of AEs comparable to severe isolated aortic stenosis and should be followed as such. Patients with severe MAVD should be evaluated at least every 6 months because half of them will become symptomatic and require AVR within 1 year.

Imaging Findings of Congestive Hepatopathy

Congestive hepatopathy (CH) refers to hepatic abnormalities that result from passive hepatic venous congestion. Prolonged exposure to elevated hepatic venous pressure may lead to liver fibrosis and cirrhosis. Liver dysfunction and corresponding clinical signs and symptoms typically manifest late in the disease process. Recognition of CH at imaging is critical because advanced liver fibrosis may develop before the condition is suspected clinically. Characteristic findings of CH on conventional images include dilatation of the inferior vena cava and hepatic veins; retrograde hepatic venous opacification during the early bolus phase of intravenous contrast material injection; and a predominantly peripheral heterogeneous pattern of hepatic enhancement due to stagnant blood flow. Extensive fibrosis can be seen in chronic or severe cases. Hyperenhancing regenerative nodules that may retain hepatobiliary contrast agents are often present. Magnetic resonance (MR) elastography can show elevated liver stiffness and may be useful in evaluation of fibrosis in CH because it can be incorporated easily into routine cardiac MR imaging. Preliminary experience with MR elastography suggests its future use in initial evaluation of patients suspected of having CH, for monitoring of disease, and for assessment after therapy. To facilitate appropriate workup and treatment, radiologists should be familiar with findings suggestive of CH at radiography, ultrasonography, computed tomography, MR imaging, and MR elastography. In addition, knowledge of underlying pathophysiology, comparative histologic abnormalities, and extrahepatic manifestations is useful to avoid diagnostic pitfalls and suggest appropriate additional diagnostic testing. (©)RSNA, 2016.

Prevalence and outcome of thrombotic and embolic complications in adults after Fontan operation

Background There are limited studies of thrombotic and embolic complications (TEC) in the adult Fontan population. The purpose of the study was to determine the prevalence, risk factors, and outcomes of TECs in this population. Methods Retrospective review of adults with a previous Fontan operation, with follow‐up at Mayo Clinic, 1994‐2014. Systemic TEC was defined as intracardiac thrombus, ischemic stroke, or systemic arterial embolus. Nonsystemic TEC was defined as Fontan conduit/right atrial thrombus or pulmonary embolus. Results We identified 387 patients with a mean (SD) age of 28 (7) years and a mean follow‐up of 8 (2) years. An atriopulmonary connection (APC) was done for 286 patients (74%). Atrial arrhythmias were present in 278 (72%). There were 121 TECs (systemic n = 36, nonsystemic n = 85) in 98 patients (25%). Risk factors for systemic TEC were atrial arrhythmia (hazard ratio 2.28, P = .001) and APC (hazard ratio 1.98, P = .02); nonsystemic TEC also had similar risk factors. All 98 patients received warfarin. Warfarin was discontinued in 10 of 98 because of bleeding, and 8 of these 10 subsequently had a second TEC. Among the 82 patients who had follow‐up imaging, 16 (20%) had resolution of thrombus. In total, 24 of 98 patients had a second TEC, most of whom had inadequate anticoagulation. Conclusions Thrombotic and embolic complication was not uncommon; risk factors for TEC were APC and atrial arrhythmias. Most patients were treated successfully with warfarin alone. A second TEC occurred in most patients whose anticoagulation was discontinued because of bleeding events.

When is the right time for Fontan conversion? The role of cardiopulmonary exercise test

BACKGROUND To determine if Fontan conversion (FC) resulted in improvement in exercise capacity (EC), and to determine the role of cardiopulmonary exercise test (CPET) in risk stratification of patients undergoing FC. METHODS A retrospective review of patients who underwent CPET prior to FC at Mayo Clinic from 1994 to 2014. The patients who also underwent post-operative CPET were selected for the analysis of improvement in EC defined as 10% increase in baseline peak oxygen consumption (VO2). RESULTS 75 patients CPET prior to FC; mean age 24±6years; 44 males (59%); and 51 (68%) were in NYHA III/IV prior to FC. Pre-operative peak VO2 was 15.5±3.4ml/kg/min. A comparison of pre- and post-FC CPET data was performed using 42 patients (56%) that underwent CPET after FC. Improvement in EC occurred in 18 of 42 patients (43%). Baseline peak VO2 >14ml/kg/min was associated with improved EC (hazard ratio [HR] 1.85; P=.02). Improvement in New York Heart Association (NYHA) class occurred in 12 (67%) patients with improved EC vs 2 (8%) without improved EC. Improvement in NYHA class was more likely to occur in patients with improved EC compared to those without improvement EC (odds ratio 4.11, P=.01). There were 10 (13%) perioperative deaths, and baseline peak VO2 ≤14ml/kg/min was predictive of perioperative mortality (HR 3.74; P<.001). CONCLUSIONS Baseline peak VO2 was predictive of perioperative survival, and improvement in EC. Performance on CPET in failing Fontan patients might be a useful clinical parameter in determining appropriate timing of FC.

Transcatheter closure of postmyocardial infarction, iatrogenic, and postoperative ventricular septal defects: The Mayo Clinic experience.

To determine event‐free survival after transcatheter closure of ventricular septal defect (VSD), and to identify predictors of adverse events (AE) in post myocardial infarction VSD (post‐MI VSD) subgroup.

Frequency and severity of hypoglycemia in children with beta-blocker-treated long QT syndrome

BACKGROUND Hypoglycemia is a potential side effect of beta-blockers; however, no cases have been reported in children with long QT syndrome (LQTS). OBJECTIVE The purpose of this study was to determine the frequency and severity of hypoglycemia among children with beta-blocker-treated LQTS. METHODS A retrospective study was performed to identify children with LQTS evaluated from 2000 to 2014 who developed symptomatic hypoglycemia while being treated with a beta-blocker. RESULTS Nine children (3%; 7 boys; average corrected QT interval 486 ± 35 ms) developed 13 episodes (0.005 events per 100 treatment years) of beta-blocker-associated hypoglycemia (mean initial glucose 21 ± 7 mg/dL), including 3 of 157 patients with LQTS type 1 (LQT1; 1.9%) and 6 of 105 with LQTS type 2 (LQT2; 5.7%). The mean age at hypoglycemic event was 3.5 ± 2 years (range 7 months to 9 years), involving nadolol in 6 cases (mean dose 1.4 ± 0.2 mg/kg/d) and propranolol in 3 (mean dose 2.7±1 mg/kg/d). Hypoglycemic events were more frequent in patients with LQT2 than in those with LQT1 (10 vs. 3 events; P = .02). Hypoglycemia-triggered seizures were observed in 6 patients, fasting ketoacidosis in 5, and 7 patients required hospitalization (mean of 3 ± 2 days). Decreased caloric intake before the event was identified in all patients and a concomitant viral infection in 3. CONCLUSION This is the largest single-center case series of beta-blocker-induced hypoglycemia. Clinicians should be cognizant of hypoglycemia symptoms in younger children during periods of poor appetite and during viral illness, and parents of these children should be educated about the signs and symptoms of hypoglycemia. A potential LQT2-hypoglycemia genotype-phenotype relationship warrants further investigation.