There was a direct correlation between the NT-pro-BNP values and hsPDA echo criteria: for PDA r = 0.60, p = 0.01 (95% CI 0.31–0.68), determination coefficient r2 = 0.36 (Figure 3), for retrograde blood flow in the postductal aorta r = 0.51, p = 0.05 (95% CI 0.26–0.66), r2 = 0.26, for the left atrium/aorta LA/Ao ratio r = 0.51, p = 0.05 (95% CI 0.34–0.70), r2 = 0.26. The gene discussed is NPPB; the disease is Patent ductus arteriosus.