The present invention relates to therapies for the treatment of cardiovascular diseases, particularly the delivery of therapeutic agents to heart tissue by direct infusion into the coronary circulation. A preferred embodiment of the invention is the use of a therapeutic polynucleotide composition adapted to transfect cardiac cells in the preparation of a medicament for treating or preventing cardiac disease by infusing the polynucleotide into a blood vessel of the coronary circulation over a period of at least three minutes, without isolating the coronary circulation from the systemic circulation. In a further preferred embodiment, the polynucleotide comprises a SERCA2a coding sequence packaged in a DNase resistant particle (DNP) of an AAV2/1 viral vector, the total number of DRP infused is less than or equal to 1 x 10 13 , and the blood vessel is the right or left coronary artery.
