Cardiac drug delivery system and method of use

Abstract

A system is disclosed, for administering a therapeutic agent locally and to a depth within cardiac tissue. An elongate, flexible catheter contains a flexible electric conductor and supports at its distal end an implantable electrode incorporating a penetrating element, typically a fixation helix or a linear needle that penetrates cardiac tissue as the electrode is implanted. A therapeutic agent is delivered through the electrode, to the cardiac tissue surrounding the penetrating element. The electrode can act as a sensor to monitor an electrical condition of the surrounding cardiac tissue and to control delivery of the agent responsive to the sensed electrical condition. Several embodiments feature a distal reservoir adjacent the electrode, for effecting transient deliveries of the therapeutic agent in minute quantities. Other embodiments are disclosed for providing sustained deliveries of agents.

1 - 38 . (canceled)  
   
   
       39 . An apparatus for treating tissue in the region of the heart to reduce the incidence of restenosis, including: 
 an elongate, flexible, biocompatible carrier having a proximal end, a distal end, and an internal volume containing a fluid including a pharmacological agent adapted to reduce the incidence of restenosis in a body lumen, wherein the carrier is adapted for intraluminal conveyance to a treatment site in the region of the heart; and    a tissue penetrating structure supported with respect to the distal end of the carrier, adapted for a penetration of tissue at the treatment site to a depth within surrounding tissue to secure the tissue penetrating structure within the tissue, and further to effect a local delivery of the fluid from the internal volume into the surrounding tissue;    wherein the carrier is operable at said proximal end to cause said penetration.    
   
   
       40 . The apparatus of  claim 39  wherein: 
 the carrier comprises a catheter, and the internal volume comprises a catheter lumen running axially along the catheter between the proximal and distal ends.    
   
   
       41 . The apparatus of  claim 40  further including: 
 a fluid source coupled to the proximal end of the catheter to supply the fluid to the tissue penetrating structure via the catheter lumen.    
   
   
       42 . The apparatus of  claim 39  wherein: 
 the internal volume comprises a reservoir at the distal end of the carrier.    
   
   
       43 . The apparatus of  claim 39  wherein: 
 the tissue penetrating structure includes a tissue penetrating element that is hollow to define an internal passage having a proximal opening to receive the fluid from the internal volume, and at least one distal opening to deliver the fluid to the surrounding tissue when the penetrating element is penetrated in said tissue.    
   
   
       44 . The apparatus of  claim 43  wherein: 
 the penetrating element comprises a helical coil adapted to so secure the tissue penetrating structure.    
   
   
       45 . The apparatus of  claim 43  wherein: 
 the tissue penetrating element comprises a substantially linear needle, and the tissue penetrating structure further includes a fixation element adapted to so secure the tissue penetrating structure.    
   
   
       46 . The apparatus of  claim 39  wherein: 
 the pharmacological agent comprises an anti-ischemic agent.    
   
   
       47 . The apparatus of  claim 39  further including: 
 an elongate and flexible electrical conductor coextensive with the carrier and electrically coupled to the penetrating element, wherein the penetrating element is electrically conductive.    
   
   
       48 . An apparatus for treating tissue in the region of the heart to reduce the incidence of reflow injury, including: 
 an elongate, flexible, biocompatible carrier having a proximal end, a distal end, and an internal volume containing a fluid including a pharmacological agent adapted to reduce the incidence of reflow injury in a body lumen, wherein the carrier is adapted for intraluminal conveyance to a treatment site in the region of the heart; and    a tissue penetrating structure supported with respect to the distal end of the carrier, adapted for a penetration of tissue at the treatment site to a depth within surrounding tissue to secure the tissue penetrating structure relative to said tissue, and fPat.urther to effect a local delivery of the fluid from the internal volume into the surrounding tissue;    wherein the carrier is operable at the proximal end to cause said penetration.    
   
   
       49 . The apparatus of  claim 48  wherein: 
 the carrier comprises a catheter, and the internal volume comprises a catheter lumen running axially along the catheter between the proximal and distal ends.    
   
   
       50 . The apparatus of  claim 49  further including: 
 a fluid source coupled to the proximal end of the catheter to supply the fluid to the tissue penetrating structure via the catheter lumen.    
   
   
       51 . The apparatus of  claim 48  wherein: 
 the internal volume comprises a reservoir at the distal end of the carrier.    
   
   
       52 . The apparatus of  claim 48  wherein: 
 the tissue penetrating structure includes a tissue penetrating element that is hollow to define an internal passage having a proximal opening to receive the fluid from the internal volume, and at least one distal opening to deliver the fluid to the surrounding tissue when the penetrating element is penetrated in said tissue.    
   
   
       53 . The apparatus of  claim 52  wherein: 
 the penetrating element comprises a helical coil.    
   
   
       54 . The apparatus of  claim 52  wherein: 
 the tissue penetrating element comprises a substantially linear needle, and the tissue penetrating structure further includes a fixation element adapted to so secure the tissue penetrating structure.    
   
   
       55 . The apparatus of  claim 48  wherein: 
 the pharmacological agent is selected from the group of agents consisting of: metabolic agents, anti-ischemic agents, and their combinations.    
   
   
       56 . The apparatus of  claim 48  further including: 
 an elongate and flexible electrical conductor coextensive with the carrier and electrically coupled to the penetrating element, wherein the penetrating element is electrically conductive.    
   
   
       57 . A process for treating tissue in the region of the heart, to reduce the incidence of restenosis, including: 
 identifying a treatment site situated in the region of the heart and subject to a risk of restenosis;    using an elongate, flexible carrier that supports at its distal end a fluid delivery structure including a distal tissue penetrating structure, to intraluminally deliver the fluid delivery structure to the treatment site and to effect a penetration of the tissue penetrating structure to a depth within tissue at the treatment site, whereby the tissue penetrating structure is surrounded by the tissue and the fluid delivery structure is secured relative to the tissue by virtue of said penetration;    selecting a treatment agent adapted to reduce the incidence of restenosis; and    after effecting said penetration, delivering a fluid including the selected treatment agent from an internal volume of the carrier through the penetrating structure into the surrounding tissue.    
   
   
       58 . The process of  claim 57  wherein: 
 said delivering comprises conveying the fluid to the tissue penetrating structure via a carrier lumen running axially along the carrier.    
   
   
       59 . The process of  claim 57  wherein: 
 the fluid delivery structure defines an internal passage having at least one distal opening in the tissue penetrating structure, and said delivering comprises delivering the fluid through the internal passage towards the at least one distal opening.    
   
   
       60 . The process of  claim 57  further including: 
 providing a reservoir near the distal end of the carrier for containing the fluid, wherein said delivering comprises providing the fluid from the reservoir to the fluid delivery structure.    
   
   
       61 . The process of  claim 57  wherein: 
 selecting the treatment agent comprises selecting an anti-ischemic agent.    
   
   
       62 . The process of  claim 57  wherein: 
 identifying a treatment site comprises selecting a treatment site within a body lumen.    
   
   
       63 . The process of  claim 57  wherein: 
 identifying the treatment site comprises selecting an intramyocardial site for delivery of the fluid.    
   
   
       64 . The process of  claim 57  wherein: 
 said delivering comprises effecting a sustained delivery of the treatment agent that is localized to the surrounding tissue.    
   
   
       65 . The process of  claim 57  wherein: 
 said identifying a treatment site includes identifying a treatment site within the heart.    
   
   
       66 . A process for treating tissue in the region of the heart, to reduce the incidence of reflow injury, including: 
 identifying a treatment site situated in the region of the heart and subject to a risk of reflow injury;    using an elongate, flexible carrier that supports at its distal end a fluid delivery structure including a distal tissue penetrating structure, to intraluminally deliver the fluid delivery structure to the treatment site and to effect a penetration of the tissue penetrating structure to a depth within tissue at the treatment site, whereby the tissue penetrating structure is surrounded by the tissue and the fluid delivery structure is secured relative to the tissue by virtue of said penetration;    selecting a treatment agent adapted to reduce the incidence of reflow injury; and    after effecting said penetration, delivering a fluid including the selected treatment agent from an internal volume of the carrier through the penetrating structure into the surrounding tissue.    
   
   
       67 . The process of  claim 66  wherein: 
 said delivering comprises conveying the fluid to the tissue penetrating structure via a carrier lumen running axially along the carrier.    
   
   
       68 . The process of  claim 66  wherein: 
 the fluid delivery structure defines an internal passage having at least one distal opening in the tissue penetrating structure, and said delivering comprises delivering the fluid through the internal passage towards the at least one distal opening.    
   
   
       69 . The process of  claim 66  further including: 
 providing a reservoir near the distal end of the carrier for containing the fluid, wherein said delivering comprises providing the fluid from the reservoir to the fluid delivery structure.    
   
   
       70 . The process of  claim 66  wherein: 
 selecting the treatment agent comprises selecting an agent from the group consisting of: metabolic agents, anti-ischemic agents, and their combinations.    
   
   
       71 . The process of  claim 66  wherein: 
 identifying a treatment site comprises selecting a treatment site within a body lumen.    
   
   
       72 . The process of  claim 66  wherein: 
 identifying the treatment site comprises selecting an intramyocardial site for delivery of the fluid.    
   
   
       73 . The process of  claim 66  wherein: 
 said delivering comprises effecting a sustained delivery of the treatment agent that is localized to the surrounding tissue.