Myocardial mass affects diagnostic performance of non-hyperemic pressure-derived indexes in the assessment of coronary stenosis

Background Several non-hyperemic pressure-derived Indexes (NHPI) have been introduced for the assessment of coronary stenosis, showing a good correlation with fractional flow reserve (FFR). Notably, either the assessment of NHPI during adenosine administration (NHPIADO) or the Hybrid Approach (NHPIHA), combining NHPI with FFR, have been showed to increase the accuracy of such indexes. It remains unclear whether diagnostic performance might be affected by the extent of the subtended myocardial mass. Methods. We enrolled consecutive patients with an intermediate coronary stenosis assessed with NHPI and FFR. NHPI were also measured during adenosine (ADO) administration (NHPIADO). The amount of jeopardized myocardium was assessed using the Duke Jeopardy Score (DJS). With FFR as reference, we assessed the accuracy of NHPI, NHPIADO and NHPIHA according to the extent of the subtended myocardium. Results. One-hundred-seventy stenoses from 151 patients were grouped according to the DJS as follows: A) Small Extent (SE, n = 82); B) Moderate Extent (ME, n = 53); C) Large Extent (LE, n = 35). As compared with FFR, NHPI showed a significantly different accuracy, as assessed by the Youden's index, according to the extent of the jeopardized myocardium (SE: 0.39 ± 0.05, ME: 0.68 ± 0.06, LE: 0.28 ± 0.06, p < 0.001). Conversely, both the NHPIADO (SE: 0.76 ± 0.02, ME: 0.88 ± 0.02, LE: 0.82 ± 0.02, p = 0.72) and NHPIHA (SE: 0.82 ± 0.07, ME: 0.84 ± 0.02, LE: 0.88 ± 0.02, p = 0.70) allowed for a better diagnostic accuracy regardless of the amount of myocardium subtended. Conclusions. Diagnostic performance of NHPI might be affected by the extent of myocardial territory subtended by the coronary stenosis. A hybrid approach might be useful to overcome this limitation.