Pressure-wire based assessment of microvascular resistance using calibrated upstream balloon obstruction: a predictor of myocardial viability

Catheter Cardiovasc Interv. 2012 Oct 1;80(4):581-9. doi: 10.1002/ccd.23277. Epub 2011 Oct 5.

Abstract

Objectives: We assess microvascular integrity as a marker of myocardial viability after coronary stenting, using only a pressure guidewire.

Background: Microvascular integrity generally is not assessed using pressure-only guidewires because the transducer lies upstream of microvasculature. We partially inflate a balloon inside a coronary stent to achieve a specific normalized pressure drop at rest (distal coronary/aortic pressure = 0.8) and then infuse a vasodilator, to render the wire sensitive to microvascular function. We hypothesize that the further decline in pressure (ΔFFR(0.8) ) predicts MRI myocardial viability.

Methods: We studied 29 subjects with acute coronary syndrome including myocardial infarction. After successful culprit stenting, the resting coronary/aortic pressure was set to 0.8 using temporary balloon obstruction. ΔFFR(0.8) was defined as 0.8-(distal coronary/aortic pressures) during adenosine-induced hyperemia. The average transmural extent of infarction was defined as the average area of MRI late gadolinium enhancement (after 2.8 ± 1.5 days) divided by the corresponding full thickness of the gadolinium enhanced sector in short axis slices, and was compared with ΔFFR(0.8) .

Results: ΔFFR(0.8) corresponded inversely and linearly with the average transmural extent of infarction (r(2) = 0.65, P < 0.001). We found that a transmural extent of infarction of 0.50 corresponded to a ΔFFR(0.8) threshold of 0.1, and had high sensitivity and specificity (100% and 94.4%, respectively).

Conclusions: Using only an upstream pressure-sensitive guidewire and a partially obstructing balloon during pharmacologic hyperemia, we were able to predict MRI myocardial viability with high accuracy after relief of epicardial stenosis. With further validation, this may prove a useful clinical prognostic tool after percutaneous intervention.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't
  • Validation Study

MeSH terms

  • Acute Coronary Syndrome / diagnosis*
  • Acute Coronary Syndrome / pathology
  • Acute Coronary Syndrome / physiopathology
  • Acute Coronary Syndrome / therapy
  • Adenosine
  • Aged
  • Angioplasty, Balloon, Coronary* / instrumentation
  • Blood Pressure
  • Calibration
  • Cardiac Catheterization* / instrumentation
  • Cardiac Catheterization* / standards
  • Cardiac Catheters
  • Chi-Square Distribution
  • Female
  • Fractional Flow Reserve, Myocardial*
  • Humans
  • Hyperemia / physiopathology
  • Linear Models
  • Magnetic Resonance Imaging, Cine
  • Male
  • Microcirculation*
  • Middle Aged
  • Multivariate Analysis
  • Myocardial Infarction / diagnosis*
  • Myocardial Infarction / pathology
  • Myocardial Infarction / physiopathology
  • Myocardial Infarction / therapy
  • Myocardium / pathology*
  • Predictive Value of Tests
  • Prospective Studies
  • Reproducibility of Results
  • Sensitivity and Specificity
  • Stents
  • Tissue Survival
  • Transducers, Pressure
  • Treatment Outcome
  • Vascular Resistance*
  • Vasodilator Agents

Substances

  • Vasodilator Agents
  • Adenosine