A novel coronary angiography index (DILEMMA score) for prediction of functionally significant coronary artery stenoses assessed by fractional flow reserve: A novel coronary angiography index

Background Angiographic evaluation of diameter stenosis has modest predictive value for functionally significant coronary artery stenoses as assessed by fractional flow reserve (FFR). Lesion length and assessment of area of myocardium at risk (Bypass Angioplasty Revascularization Investigation [BARI] Myocardial Jeopardy Index [MJI]) subtended by the stenotic coronary arteries are also predictors of functionally significant coronary artery stenoses. We sort to assess the diagnostic accuracy of DILEMMA score, which combines minimal lumen diameter (MLD), lesion length, and BARI MJI in prediction of significantly reduced FFR (<= 0.8). Methods We assessed patients who underwent coronary angiography and FFR. Lesion length and MLD were assessed by quantitative coronary angiography. Estimation of area of myocardium at risk subtended by coronary stenoses was performed using the BARI MJI. Results A total of 296 patients (age 64 +/- 10.6 years, 68% male, 497 vessels) were included. DILEMMA score was significantly higher in vessels with significant FFR, 6.09 +/- 3.23 versus 3.84 +/- 2.99 (P < .001). In the derivation cohort, the optimism-adjusted Harrell c statistic for DILEMMA score was 0.82 compared with 0.76 for BARI MJI, 0.75 for lesion length, and 0.7 for MLD. In the validation cohort, the c-statistic for DILEMMA score, BARI MJI, lesion length, and MLD was 0.88, 0.77, 0.81, and 0.72, respectively. The DILEMMA score was a better predictor of FFR <= 0.8 compared with MLD, lesion length, and BARI MJI individually (P < .001, P < .02, and P < .045, respectively) on Bonferroni-adjusted pairwise comparison. Conclusions DILEMMA score, taking into account MLD, lesion length, and BARI MJI, may have incremental predictive value beyond the individual indices alone for detecting functionally significant coronary artery stenoses.