Intracoronary pressures to predict myocardial viability in patients with ischemic left ventricular dysfunction.

To investigate the role of intracoronary pressure parameters in the assessment of viability in the myocardium subtending a significant coronary stenosis. In patients with ischemic left ventricular dysfunction, the presence of myocardial viability is related to the expected benefits derived from coronary revascularization. Intracoronary pressure wire-based measurements were performed in 64 coronary lesions of ≥50% stenosis severity of 59 patients with postischemic left ventricular dysfunction, segmental left ventricular wall motion abnormalities, and substantial viability in the myocardial territory subtending the investigated stenotic coronaries, defined as the percent summed rest score in the target territory (%SRStarget ) ≤60% at the single-photon emission tomography. Invasive pressure-derived indexes like resting and hyperemic Pd/Pa, ΔPd/Pa, and %ΔPd/Pa (defined as the absolute difference and percent decrease between resting and hyperemic Pd/Pa respectively) were compared with %SRStarget . A significant correlation was found between ΔPd/Pa (Spearman's p: -0.760, p < 0.001) and %ΔPd/Pa (p: -0.733; p < 0.001) with %SRStarget. These results were confirmed after correction for potential confounders. According to %SRStarget median value, myocardial areas with high and low viability were compared: ΔPd/Pa and %ΔPd/Pa were significantly higher in areas with high viability (p < 0.001 for both). According to receiver operating characteristic curves, we identified two cut-offs (ΔPd/Pa > 0.11 and %ΔPd/Pa > 15%) able to predict >80% viability with good sensitivity and specificity. Our study suggests that, in patients with postischemic left ventricular dysfunction and significant coronary stenosis, intracoronary pressures indexes like ΔPd/Pa and %ΔPd/Pa are able to predict the magnitude of downstream myocardial viability.