Noninvasive Evaluation of Ventricular Filling Pressure and Pulmonary Vascular Reserve in Adults With Fontan Circulation.

BACKGROUND

Exercise cardiac catheterization is the gold standard for diagnosing diastolic dysfunction and impaired pulmonary reserve in patients with Fontan circulation. The diagnostic value of noninvasive parameters is unclear.

METHODS

Patients who underwent simultaneous exercise hemodynamic evaluation and peripheral venous pressure (PVP) measurement were included. Echocardiographic surrogates for ventricular filling pressure were compared with invasive measures. Diastolic dysfunction was defined invasively as either resting pulmonary artery wedge pressure ≥12 mm Hg or exercise pulmonary artery wedge pressure >20 mm Hg.

RESULTS

Twenty-nine patients were included. Age at catheterization was 34±9 years. Atrioventricular valve systole-to-diastole duration ratio (S/D) and resting PVP were significant predictors of resting pulmonary artery wedge pressure (S/D: β=0.71 per 0.1 S/D [95% CI, 0.16-1.25]; P=0.01; PVP: β=0.68 per mm Hg [95% CI, 0.41-0.96]; P<0.001). By contrast, resting PVP was a predictor of diastolic dysfunction, whereas S/D was not. Based on these data, we proposed a 2-tier assessment algorithm with the first tier considering resting PVP ≤15 mm Hg and S/D ≤1.1 and the second tier considering exercise PVP ≤25 mm Hg in those with 1 elevated resting parameter. This algorithm showed a positive predictive value of 88% (95% CI, 47%-100%), a negative predictive value of 90% (95% CI, 70%-99%), a sensitivity of 78% (95% CI, 40%-97%), and a specificity of 95% (95% CI, 75%-100%). Exercise PVP indexed to peak oxygen consumption also predicted invasively measured exercise pulmonary vascular resistance index (β=0.36 WU·m2 per mm Hg/100 mL per min [95% CI, 0.08-0.64]; P=0.01).

CONCLUSIONS

This study presents a simple, noninvasive approach for evaluating diastolic function and pulmonary vascular reserve in patients with a Fontan circulation.