Dissertation Alissia Quattrone

Cand.med. Alissia Quattrone from ProCardio defended the thesis “Risk stratification in adults operated for tetralogy of Fallot” for the degree of PhD (Philosophiae Doctor) on the 23rd of September, 2022. The trial lecture was titled “Multimodality imaging and assessment of right ventricular function in congenital heart disease”.

Published 7/8/2024
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Digital Public Defence: Alessia Quattrone - Institute of Clinical Medicine (uio.no)

Adjudication committee 
First opponent: Assistant Professor Rafael Alonso-Gonzalez, Toronto General Hospital, Canada
Second opponent: Senior Consultant Assami Rösner, UiT - The Arctic University of Norway
Third member and chair of the evaluation committee: Associate Professor John-Peder Escobar Kvitting, University of Oslo

Chair of the Defence 
Professor Annetine Staff, University of Oslo

Principal Supervisor
Consultant cardiologist Mette-Elise Estensen, University of Oslo

Summary
Tetralogy of Fallot (TOF) is the most common cyanotic congenital heart diseases. It consists of a combination of four cardiac defects: ventricular septal defect, right ventricular outflow obstruction, right ventricular hypertrophy and over-riding of the aorta. The surgical correction of the anatomical defects is performed within the first months of life.

Life expectancy and quality of life in patients operated for TOF have increased importantly. In female patients pregnancy is usually well tolerated. However, adults operated for TOF are subject to higher mortality rate than in the general population, and complications as ventricular arrhythmias (VA) and sudden cardiac death represent major concerns.

Despite yearly follow-up, it is not easy to identify patients with higher risk of complications, as well as it is not clear whether pregnancy have an influence on the long term.

We aimed to improve the identification of risk factors that contribute to complications in adult operated for TOF. Furthermore, we aimed to investigate the influence of pregnancy on the long term outcome in females.

We selected patients >18 years old diagnosed for TOF and with history of complete surgical correction. A subgroup of patients was investigated with echocardiography and cardiac magnetic resonance.

We showed that almost one out of four adults operated for TOF experience VA about thirty years after surgical repair. The incidence of VA was similar in males and females. Males had more left ventricle (LV) and right ventricle (RV) dysfunction compared to females, expressed by lower RV and LV global longitudinal strain values and lower LV ejection fraction values. 

Experienced pregnancy was associated with higher prevalence of VA, being the increased risk expressed by higher RV mechanical dispersion and higher values of NT-proBNP, independently of age. Pregnancy seems not to cause alterations in RV and LV volumes, heart function, or grade of fibrosis.