Devices, systems, and methods for assessment of vessels

Abstract

Devices, systems, and methods for visually depicting a vessel and evaluating treatment options are disclosed. The methods can include introducing instruments into the vessel of a patient and obtaining proximal and distal pressure measurements of a stenosis of the vessel, calculating a pressure ratio based on the obtained proximal and distal pressure measurements, applying a correlation factor to the calculated pressure ratio to produce a predicted diagnostic pressure ratio, and displaying the predicted diagnostic pressure ratio to a user.

What is claimed is: 
     
         1 . A system for evaluating a vessel of a patient, comprising:
 a processor configured for communication with at least an intravascular pressure-sensing catheter or guidewire, wherein the processor is configured to:
 obtain, from at least the intravascular pressure-sensing catheter or guidewire, pressure measurements associated with the vessel without using a hyperemic agent; 
 calculate a non-hyperemic, non-diagnostic pressure ratio based on the pressure measurements; 
 determine a predicted diagnostic pressure ratio by applying a correlation factor to the non-hyperemic, non-diagnostic pressure ratio, wherein the predicted diagnostic pressure ratio correlates to a diagnostic pressure ratio that is clinically accepted to be diagnostic; and 
 cause a display to display the predicted diagnostic pressure ratio. 
   
     
     
         2 . The system of  claim 1 , wherein the pressure measurements comprise:
 one or more first pressure measurements associated with a location distal of a stenosis of the vessel; and   one or more second pressure measurements associated with a location proximal of the stenosis of the vessel.   
     
     
         3 . The system of  claim 2 , wherein the processor is configured to calculated the non-hyperemic, non-diagnostic pressure ratio based on a comparison of the one or more first pressure measurements and the one or more second pressure measurements. 
     
     
         4 . The system of  claim 1 , wherein the predicted diagnostic pressure ratio comprises at least one of fractional flow reserve (FFR) or instantaneous wave-free ratio (iFR). 
     
     
         5 . The system of  claim 1 , wherein the correlation factor comprises a fixed value. 
     
     
         6 . The system of  claim 1 , wherein the correlation factor comprises a variable value. 
     
     
         7 . The system of  claim 1 , wherein the correlation factor comprises a first correlation value for calculated non-hyperemic, non-diagnostic pressure ratios below a first threshold, a second correlation value for calculated non-hyperemic, non-diagnostic pressure ratios between the first threshold and a second threshold, and a third correlation value for calculated non-hyperemic, non-diagnostic pressure ratios above the second threshold. 
     
     
         8 . The system of  claim 1 , wherein the correlation factor is based on a relationship of a plurality of non-hyperemic, non-diagnostic pressure ratio values and a plurality of diagnostic pressure ratio values. 
     
     
         9 . The system of  claim 8 , wherein the correlation factor is based on a slope of a plot of the plurality of non-hyperemic, non-diagnostic pressure ratio values and the plurality of diagnostic pressure ratio values. 
     
     
         10 . The system of  claim 8 , wherein the correlation factor is based on a relationship of a measure of curvature of a plot of the plurality of non-hyperemic, non-diagnostic pressure ratio values and the plurality of diagnostic pressure ratio values. 
     
     
         11 . The system of  claim 8 , wherein the correlation factor is based on a relationship of an area below a curve of a plot of the calculated non-hyperemic, non-diagnostic pressure ratios and the plurality of diagnostic pressure ratio values. 
     
     
         12 . The system of  claim 1 , wherein the correlation factor is based on at least one characteristic of the patient. 
     
     
         13 . The system of  claim 1 , wherein the processor is configured to calculate the non-hyperemic, non-diagnostic pressure ratio based on an average distal pressure measurement of the pressure measurements and an average proximal pressure measurement of the pressure measurements. 
     
     
         14 . The system of  claim 13 , wherein the average distal pressure measurement and the average proximal pressure measurement are calculated over an entire heartbeat cycle. 
     
     
         15 . The system of  claim 1 , further comprising the intravascular pressure-sensing catheter or guidewire.