Chasing a moving target: outcome and risk stratification in patients with transposition of the great arteries after atrial switch operation

Abstract

This editorial refers to ‘The natural and unnatural history of the Mustard procedure: long-term outcome up to 40 years’[†][1], by J.A.A.E. Cuypers et al. , on page 1666 Before the advent of the atrial switch operation, hardly any infant born with complete transposition of the great arteries (TGA) survived beyond the first year of life. In the 1950s and 1960s, two operations introduced by Senning and Mustard, respectively, revolutionized the outcome of the condition, allowing patients to survive well into adulthood.1,2 However, ongoing long-term complications, as well as increased morbidity and mortality remain an issue even five decades later. This type of physiological repair has now been largely replaced by the arterial switch procedure.3 Today it continues to be reserved only for highly selected cases and has, thus, become part of medical history more than being a viable treatment option. Patients after Mustard or Senning (M/S) repair are afflicted by three main problems: (i) loss of sinus rhythm and arrhythmias; (ii) right (systemic) ventricular dysfunction leading to heart failure; and (iii) problems with baffle obstruction or leaks. These complications add to morbidity and induce excess mortality in this population.4 Since the introduction of surgical correction, cardiac surgeons, paediatric cardiologists, and later adult congenital cardiologists continue to study these problems. This has led to a considerable and growing body of literature delineating the prevalence of complications and trying to predict future problems based on surgical and/or medical history. Since 1990, >20 studies, including over 3500 patients, have dealt with these issues ( Table 1 ). However, risk stratification remains an unsolved problem in this population. Late mortality appears to be due to two main problems: (i) sudden cardiac death; and (ii) heart failure-related mortality.5,6 Both remain problematic but create challenges at different levels: while the first … [1]: #fn-2