Relation between preoperative left ventricular muscle mass and outcome of the fontan procedure in patients with tricuspid atresia

Abstract

The relation between preoperative left ventricular muscle mass and clinical outcome of the Fontan procedure was evaluated retrospectively in 22 patients with tricuspid atresia who were selected for this physiologic surgical correction by conventional hemodynamic criteria. Patients were divided into two groups: group A (excellent or good outcome) and group B (poor outcome or death) based on the clinical course assessed up to 9.5 years postoperatively.Thirteen of 22 group A patients did not have prolonged, clinically significant, systemic venous hypertension and were not on long-term diuretic drug therapy. Nine of 22 group B patients either had clinically significant systemic venous hypertension, required long-term diuretic drug therapy or died (3 patients). Age at surgery, pulmonary arteriolar resistance, left ventricular ejection fraction, enddiastolic volume, end-diastolic pressure, systemic oxygen saturation and pulmonary to systemic blood flow ratio (Qp/Qs) were not statistically different between the two groups. Left ventricular muscle mass, both in group A patients (92 ± 31 g/m2) and in group B patients (146 ± 61 g/m2), was greater than the normal mean value (p < 0.01 and p 0.001, respectively).Left ventricular muscle mass in group B was significantly greater than in group A (p < 0.01). Furthermore, left ventricular muscle mass/end-diastolic volume (mass/ volume) ratio, reflecting the extent of left ventricular hypertrophy relative to volume overload, was significantly greater in group B (1.1 ± 0.28) than in group A (0.84 t 0.21) (p < 0.05). These findings are consistent with the observation that less satisfactory postoperative clinical outcome may, at least in part, be related to impaired diastolic function associated with inappropriately hypertrophied left ventricular myocardium.Determination of left ventricular muscle mass appears to be a useful variable to be considered along with conventional hemodynamic selection criteria for anticipating the clinical outcome in patients with tricuspid atresia considered as candidates for the Fontan procedure.