NPPB and pericardial effusion: However, no correlations were observed between METS-IR and WHO-FC (r = 0.018, P = 0.734), 6MWD (r = -0.034, P = 0.518), NT-proBNP (r = 0.073, P = 0.160), pericardial effusion (r = 0.093, P = 0.075), or TAPSE/sPAP (r = 0.085, P = 0.104).