“The Four Noble Truths” and a part of “The Heart Sutra” seem to be in perfect contrast, however, they both talk about the same thing in detail; The Four Noble Truths is the idea that the Buddha is teaching us to be free from suffering whereas The Heart Sutra states that there are no four noble truths.
Buddha teaches The Four Noble Truths to all sentient beings that have not yet crossed the sea of suffering. At this point, The Four Noble Truths is comparable to “a boat” that takes all sentient beings to get across the sea of suffering.
Meanwhile, The Heart Sutra is of a scripture explained by a Bodhisattva who had already crossed the sea of suffering and encouraged all followers to go beyond the sea of suffering.
At this point the Bodhisattva has already reached the shore and she does not need the boat anymore!