ACIST Diastolic Pressure Ratio (dPR)
Non-hyperemic index for coronary physiology
ACIST dPR is not approved in all markets including the US

ACIST diastolic pressure ratio (dPR), using the ACIST RXi® Rapid Exchange System and Navvus® MicroCatheter, provides a non-hyperemic alternative for physiological assessment of coronary disease.

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Reducing costs, time and patient discomfort

Non-hyperemic pressure ratios, such as dPR, may reduce patient discomfort*, cost** and procedural time.***

Reduced Patient Discomfort

Reduced Cost

Reduced Time

ACIST dPR algorithm

ACIST dPR is the ratio of Pd to Pa at the peak-to-peak midpoint, averaged over 5 consecutive heartbeats. ACIST dPR does not rely on an ECG signal to make the calculation.

BeatCheckTM is a signal quality monitoring algorithm to identify ectopic rhythms in the hemodynamic waveform (i.e. premature ventricular contractions and arrhythmias).

ACIST dPR by the numbers

(compare to iFRcalc)1


dPR cutpoint











Analysis of the ACIST FFR Study1


The data collected during the ACIST-FFR clinical study was retrospectively assessed by an independent, physiologic core laboratory to support ACIST’s dPR algorithm on the ACIST RXi system.


The dPR value was calculated by the application of ACIST’s fully automated off-line dPR software algorithm. iFRcalc was calculated off-line, by the same core lab, based on the original description of its derivation to determine a final value for iFR.2

Key points

  • ACIST dPR is highly correlated with iFRcalc


  • ACIST dPR provides similar diagnostic accuracy as iFRcalc


Diagnostic accuracy of dPR (cutpoint of 0.89) referenced to iFRcalc (0.89) was 98.88%


* Reduced side effect profile when comparing resting approach (iFR, dPR, Pd/Pa) to FFR with adenosine induced hyperemia
** Cost savings based on the reduced cost of utilizing a resting approach compared to conventional FFR and respective cost of admInistration of hyperemic agent (adenosine)
*** When comparing resting index (iFR, dPR, Pd/Pa) to FFR with adenosine induced hyperemia
1. Data on file TR-07879
2. Sen S, Escaned J, Malik IS, et at. Development and validation of a new adenosine-independent index of stenosis severity from coronary wave-intensity analysis: results of the ADVISE (ADenosine Vasodilator Independent Stenosis Evaluation) study. J Am Coll Cardbl. 2012:59(15)1392-1402. doi:10.1016/j.jacc.2011.11.003.

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