Pulmonary vascular disease and optical coherence tomography imaging in patients with Fontan palliation.

INTRODUCTION: The Fontan procedure is the palliative procedure of choice for patients with single ventricle physiology. Pulmonary vascular disease (PVD) is an important contributor to Fontan circulatory failure. AREAS COVERED: We review the pathophysiology of PVD in patients with Fontan palliation and share our initial experience with optical coherence tomography (OCT) in supplementing standard hemodynamics in characterizing Fontan-associated PVD. In the absence of a sub-pulmonary ventricle, low pulmonary vascular resistance (PVR; ≤2 WU/m2) is required to sustain optimal pulmonary blood flow. PVD is associated with adverse pulmonary artery (PA) remodeling resulting from the non-pulsatile low-shear low-flow circulation. Predisposing factors to PVD include impaired PA growth, endothelial dysfunction, hypercoagulable state, and increased ventricular end-diastolic pressure. OCT parameters that show promise in characterizing Fontan-associated PVD include the PA intima-to-media ratio and wall area ratio (i.e. difference between the whole-vessel area and the luminal area divided by the whole-vessel area). EXPERT OPINION: OCT carries potential in characterizing PVD in patients with Fontan palliation. PA remodeling is marked by intimal hyperplasia, with medial regression. Further studies are required to determine the role of OCT in informing management decisions and assessing therapeutic responses.

Palpitations Revealing a Primary Pulmonary Artery Sarcoma.

Primary pulmonary artery sarcoma is an exceedingly rare and aggressive malignancy that carries poor prognosis. Clinical manifestations are nonspecific and include chest pain, dyspnea, syncope, palpitations, and asthenia, among others. Delay to diagnosis is common and compromises the prognosis. Here, we report an interesting case of primary pulmonary artery sarcoma presenting with frequent monomorphic premature ventricular contractions arising from the right/left ventricle outflow tract. Cardiac imaging is key in the evaluation of patients with frequent premature ventricular contractions to rule out rare pathologies such as tumour compression.

Le sarcome primaire de l'artère pulmonaire est une tumeur maligne extrêmement rare et agressive de mauvais pronostic. Les manifestations cliniques sont non spécifiques et peuvent inclure de la douleur thoracique, de la dyspnée, des syncopes, des palpitations et de l'asthénie. Le retard diagnostic est fréquent et compromet le pronostic. Nous rapportons ici un cas intéressant de sarcome primaire de l'artère pulmonaire pour lequel le patient présentait des extrasystoles ventriculaires prématurées monomorphes qui provenaient des chambres de chasse des ventricules gauche et droit. L'imagerie est essentielle à l'évaluation des patients présentant de fréquentes extrasystoles ventriculaires afin d'écarter des pathologies rares comme la compression tumorale d'une chambre cardiaque.

Machine Learning Identifies Clinical and Genetic Factors Associated With Anthracycline Cardiotoxicity in Pediatric Cancer Survivors.

BACKGROUND: Despite known clinical risk factors, predicting anthracycline cardiotoxicity remains challenging. OBJECTIVES: This study sought to develop a clinical and genetic risk prediction model for anthracycline cardiotoxicity in childhood cancer survivors. METHODS: We performed exome sequencing in 289 childhood cancer survivors at least 3 years from anthracycline exposure. In a nested case-control design, 183 case patients with reduced left ventricular ejection fraction despite low-dose doxorubicin (≤250 mg/m2), and 106 control patients with preserved left ventricular ejection fraction despite doxorubicin >250 mg/m2 were selected as extreme phenotypes. Rare/low-frequency variants were collapsed to identify genes differentially enriched for variants between case patients and control patients. The expression levels of 5 top-ranked genes were evaluated in human induced pluripotent stem cell-derived cardiomyocytes, and variant enrichment was confirmed in a replication cohort. Using random forest, a risk prediction model that included genetic and clinical predictors was developed. RESULTS: Thirty-one genes were differentially enriched for variants between case patients and control patients (p < 0.001). Only 42.6% case patients harbored a variant in these genes compared to 89.6% control patients (odds ratio: 0.09; 95% confidence interval: 0.04 to 0.17; p = 3.98 × 10-15). A risk prediction model for cardiotoxicity that included clinical and genetic factors had a higher prediction accuracy and lower misclassification rate compared to the clinical-only model. In vitro inhibition of gene-associated pathways (PI3KR2, ZNF827) provided protection from cardiotoxicity in cardiomyocytes. CONCLUSIONS: Our study identified variants in cardiac injury pathway genes that protect against cardiotoxicity and informed the development of a prediction model for delayed anthracycline cardiotoxicity, and it also provided new targets in autophagy genes for the development of cardio-protective drugs. (Preventing Cardiac Sequelae in Pediatric Cancer Survivors [PCS2]; NCT01805778).

Eisenmenger Syndrome: A Multisystem Disorder-Do Not Destabilize the Balanced but Fragile Physiology.

Eisenmenger syndrome is the most severe and extreme phenotype of pulmonary arterial hypertension associated with congenital heart disease. A large nonrestrictive systemic left-to-right shunt triggers the development of pulmonary vascular disease, progressive pulmonary arterial hypertension, and increasing pulmonary vascular resistance at the systemic level, which ultimately results in shunt reversal. Herein, we review the changing epidemiological patterns and pathophysiology of Eisenmenger syndrome. Multiorgan disease is an integral manifestation of Eisenmenger syndrome and includes involvement of the cardiac, hematological, neurological, respiratory, gastrointestinal, urinary, immunological, musculoskeletal, and endocrinological systems. Standardized practical guidelines for the assessment, management, risk stratification, and follow-up of this very fragile and vulnerable population are discussed. Multidisciplinary care is the best clinical practice. An approach to the prevention and management of a broad spectrum of complications is provided. Relevant therapeutic questions are discussed, including anticoagulation, noncardiac surgery, physical activity, transplantation, and advanced-care planning (palliative care). Advanced pulmonary arterial hypertension therapies are indicated in patients with Eisenmenger syndrome and World Health Organization functional class II or higher symptoms to improve functional capacity, quality of life, and-less well documented-survival. Specific recommendations regarding monotherapy or combination therapy are provided according to functional class and clinical response. The ultimate challenge for all care providers remains early detection and management of intracardiac and extracardiac shunts, considering that Eisenmenger syndrome is a preventable condition.

Lead Extraction With Baffle Stenting in Adults With Transposition of the Great Arteries.

OBJECTIVES: This study sought to assess the feasibility, safety, and outcomes of a stepwise combined percutaneous approach that includes transvenous lead extraction (TLE) followed by baffle stenting and device reimplantation in patients with D-transposition of the great arteries (D-TGA) and atrial baffle dysfunction. BACKGROUND: Management of baffle leak or stenosis in patients with D-TGA and atrial switch surgery is challenging in the presence of transvenous cardiac implantable electronic devices. Baffle complications hinder device-related interventions and addressing baffle dysfunction often requires TLE. METHODS: All consecutive patients with D-TGA and TLE followed by a percutaneous baffle intervention at the Montreal Heart Institute between 2009 and 2018 were enrolled. RESULTS: Ten patients, median 38.6 years of age (range 15.2 to 50.6 years), 5 males (50.0%) were included. Procedures were performed for a device-related indication in 5 patients (50.0%) and for baffle dysfunction in 5 patients (50.0%). A total of 19 leads (17 pacing, 2 defibrillation) were targeted, with a median time from implantation of 8.7 (range 4.3 to 22.1) years. A laser sheath was most frequently required for successful TLE, which was achieved in all patients. Immediate baffle stenting was performed in 9 patients (90.0%) and immediate device reimplantation in 6 (60.0%). During a median follow-up of 3.0 (range 0.1 to 8.2) years, the only complication was subpulmonary atrioventricular valve damage requiring surgery in 1 patient, 8 months after the procedure. CONCLUSIONS: A combined approach with TLE followed by baffle stenting and reimplantation appears to be safe and feasible in D-TGA patients with atrial switch, baffle dysfunction, and transvenous leads.

Sudden death in transposition of the great arteries with atrial switch surgery: Autopsy evidence of acute myocardial ischemia despite normal coronary arteries.

BACKGROUND: Sudden death is the leading cause of mortality in patients with transposition of the great arteries (TGA) and atrial switch surgery. Understanding underlying mechanisms could contribute to identifying high-risk patients and preventing such catastrophic deaths. METHODS: A total of 144 adults (≥18 years) with TGA and atrial switch surgery were followed at our adult congenital center since 1989. Four patients were excluded: two with double-outlet right ventricles and two with subsequent arterial switch surgery in childhood. RESULTS: Of the remaining 140 patients, age 37.6 ±â€¯7.8 years, 37.1% female, 8 (6%) had a cardiac arrest of presumed arrhythmic etiology of whom 3 were resuscitated. The arrests occurred in 3 women and 5 men at age 30.5 ±â€¯8.6 (range 22 to 50) years. None had established coronary artery disease, sustained ventricular arrhythmias, or syncope. Four (50%) had atrial arrhythmias and 6 (75%) had at least moderate systemic right ventricular dysfunction. For 5 patients in whom circumstances surrounding the arrests were documented, 3 occurred on exertion, 1 after consuming recreational methamphetamine, and 1 in the context of an atrial tachyarrhythmia. Autopsies were performed in 2 of 5 patients. Both revealed acute massive myocardial infarction of the hypertrophied systemic right ventricle with normal coronary arteries and chronic subendocardial ischemic lesions. CONCLUSION: This is the first report to provide histopathological evidence in support of a myocardial ischemia hypothesis as a cause of sudden death in this patient population, despite the absence of coronary atherosclerosis.

Late Onset Postcapillary Pulmonary Hypertension in Patients With Transposition of the Great Arteries and Mustard or Senning Baffles.

BACKGROUND: There is a paucity of data regarding late-onset pulmonary hypertension (PH) in patients with transposition of the great arteries and atrial switch surgery. METHODS AND RESULTS: A retrospective cohort study was conducted on 140 adults with transposition of the great arteries and atrial switch surgery, age 37.3±7.8, 37.1% female, in order to assess the prevalence and characteristics of late-onset PH and explore associated factors. Patients were followed for a median of 32.3 years after atrial switch surgery and 10.0 years after their first referral visit. PH was detected in 18 of 33 (54.5%) patients who had invasive hemodynamic studies. Average age at diagnosis of PH was 33.9±8.1 years. PH was postcapillary in all, with a mean pulmonary artery pressure of 36±12 mm Hg and mean pulmonary capillary wedge pressure of 28±8 mm Hg. PH was diagnosed in 13 of 17 (76.5%) patients who had cardiac catheterization for heart failure or decreased exercise tolerance. In multivariable analyses, systemic hypertension (odds ratio 9.4, 95% confidence interval 2.2-39.4, P=0.002) and heart failure or New York Heart Association class III or IV symptoms (odds ratio 49.8, 95% confidence interval 8.6-289.0, P<0.001) were independently associated with PH. Patients with PH were more likely to develop cardiovascular comorbidities including atrial (P=0.001) and ventricular (P=0.008) arrhythmias, require hospitalizations for heart failure (P<0.001), and undergo tricuspid valve surgery (P<0.001). Mortality was significantly higher in patients with PH (hazard ratio 9.4, 95% confidence interval 2.1-43.0], P<0.001). CONCLUSIONS: Late-onset postcapillary PH is highly prevalent in adults with transposition of the great arteries and atrial switch surgery and is associated with an adverse prognosis.