There is no doctrinal teaching regarding “accepting Jesus into your heart”, more over the idea of “accepting Jesus into your heart” is non-biblical. This isn’t to say it’s a
bad idea, it certainly expresses something which is a good idea… It’s a good idea to accept Jesus as saviour, and accept that in a personal sense, but where I disagree is the extent which many (but not all) protistants take this. It is the central theological principal, so many churches around me teach “accept Jesus Christ into your heart as your own personal Lord and Saviour and your
saved 
”
Not quite, like Anna says it’s a good starting piont. And I would futher clarify for my part, it’s a good starting point in that now your beging the process of nurturing and building faith in Christ.
But this does not, and should not preclude the sacraments. Accepting Jesus as your personal Lord and Saviour doesn’t nullify baptism, or the need to seek reconciliation. Christians need the graces from these sacraments in order to build a good, healthy strong faith, working through love.
I would not go so far as to say “accepting Jesus into your heart IS NOT doctrine,” as scripture says you must confess Christ as Lord and be baptized in order to be saved. I think each church uses it own wording that may be different around this.
This comes from the catechism of the Roman Catholic Church on the subject of “saved.”
1226 From the very day of Pentecost the Church has celebrated and administered holy Baptism. Indeed St. Peter declares to the crowd astounded by his preaching: “Repent, and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins; and you shall receive the gift of the Holy Spirit.” The apostles and their collaborators offer Baptism to anyone who believed in Jesus: Jews, the God-fearing, pagans. Always, Baptism is seen as connected with faith: “Believe in the Lord Jesus, and you will be saved, you and your household,” St. Paul declared to his jailer in Philippi. And the narrative continues, the jailer “was baptized at once, with all his family.”
2744 Prayer is a vital necessity. Proof from the contrary is no less convincing: if we do not allow the Spirit to lead us, we fall back into the slavery of sin. How can the Holy Spirit be our life if our heart is far from him?
Nothing is equal to prayer; for what is impossible it makes possible, what is difficult, easy… For it is impossible, utterly impossible, for the man who prays eagerly and invokes God ceaselessly ever to sin.
Those who pray are certainly saved; those who do not pray are certainly damned.
2822 Our Father “desires all men to be saved and to come to the knowledge of the truth.” He “is forbearing toward you, not wishing that any should perish.” His commandment is “that you love one another; even as I have loved you, that you also love one another.” This commandment summarizes all the others and expresses his entire will.
74 God “desires all men to be saved and to come to the knowledge of the truth”: that is, of Christ Jesus. Christ must be proclaimed to all nations and individuals, so that this revelation may reach to the ends of the earth:
God graciously arranged that the things he had once revealed for the salvation of all peoples should remain in their entirety, throughout the ages, and be transmitted to all generations.
183 Faith is necessary for salvation. The Lord himself affirms: “He who believes and is baptized will be saved; but he who does not believe will be condemned” (Mk 16:16).
1054 Those who die in God’s grace and friendship imperfectly purified, although they are assured of their eternal salvation, undergo a purification after death, so as to achieve the holiness necessary to enter the joy of God.
Seems like the highlighted areas would be doctrine if you ask me.