Comparison of Outcomes in Adults With Congenitally Corrected Transposition With Situs Inversus Versus Situs Solitus

The long-term outcome of patients with congenitally corrected transposition of the great arteries is mainly determined by progressive morphologically tricuspid valve regurgitation, heart block, atrial arrhythmias, and/or systemic ventricular dysfunction. Situs abnormalities have been reported in ≤34% of cases, but whether clinical differences exist between a situs inversus and situs solitus arrangement has not yet been studied. The clinical records of 38 adults with congenitally corrected transposition of the great arteries (mean age 40 ± 15 years) followed for a mean period of 7.4 years were reviewed. Of these 38 patients, 8 presented with situs inversus and 30 with situs solitus. No significant differences were found between the 2 groups in age, gender, ventricular septal defect, pulmonary tract stenosis, previous surgical repair, or duration of follow-up. However, none of the patients with situs inversus presented with an Ebstein-like anomaly of the morphologically tricuspid valve and none developed nonoperative-related complete atrioventricular block compared to 15 (50%; p = 0.013) and 11 (42%; p = 0.032) of the patients with situs solitus, respectively. At follow-up, 2 patients with situs inversus (25%) presented with sustained atrial arrhythmia, severe tricuspid regurgitation, or severe systemic right ventricular systolic dysfunction compared to 22 (73%) of 30 those with situs solitus (p = 0.034). No patient with situs inversus presented with cardiac death or severe heart failure compared to 12 (40%) of 30 with situs solitus (p = 0.038). In conclusion, Ebstein-like anomaly or spontaneous complete atrioventricular block are rare in patients with congenitally corrected transposition of the great arteries with situs inversus, and late complications are uncommon. The long-term outcome of patients with situs inversus was significantly better than that for patients with situs solitus.