marginally significantp = 0.058
A marginally significant interaction of baseline NT-proBNP with time was observed (p = 0.058), with a significant interaction at 24 months post-RT (β = − 0.00051, p = 0.010), indicating a smaller increase, or even a slight decrease, among patients with higher baseline levels in contrast with the increase observed in patients with lower baseline NT-proBNP ( Fig. 1 ).