Factors associated with impaired clinical status in long-term survivors of tetralogy of Fallot repair evaluated by magnetic resonance imaging

OBJECTIVES The purpose of this study was to identify independent factors associated with impaired clinical status in late survivors of tetralogy of Fallot (TOF) repair. BACKGROUND Repair of TOF often results in chronic pulmonary regurgitation (PR) and right ventricular (RV) dilation, which have been linked to late morbidity and mortality. However, determinants of clinical status late after TOF repair have not been fully characterized. METHODS The clinical and laboratory data of 100 consecutive patients with repaired TOF (median 21 years after repair) who completed a cardiac magnetic resonance imaging protocol were analyzed. Impaired clinical status was defined as New York Heart Association (NYHA) functional class greater than or equal to III. RESULTS Of the patients, 88 were in NYHA functional class I or II and 12 were in NYHA functional class III. The degree of PR and indexed RV end-diastolic volume were not associated with impaired clinical status. By multivariate analysis, a lower left ventricular (LV) ejection fraction (EF) (odds ratio [OR] = 3.88 for 10% decrease, p = 0.002) and older age at TOF repair (OR = 1.70 for 5-year increase, p = 0.013) were the strongest independent factors associated with impaired clinical status. Among RV variables, a lower RV EF was the strongest independent factors associated with poor clinical status (OR = 2.41 for 10% decrease, p = 0.01). The LV EF correlated with RV EF (r = 0.58, p < 0.001). CONCLUSIONS Moderate or severe LV or RV systolic dysfunction, but not PR fraction or RV diastolic dimensions, is independently associated with impaired clinical status in long-term survivors of TOF repair. The close relationship between LV EF and RV EF suggests unfavorable ventricular ventricular interaction.