Predictors of discordance between fractional flow reserve (FFR) and diastolic pressure ratio (dPR) in intermediate coronary lesions.

BACKGROUND

Recently, non-hyperemic pressure ratios (NHPRs) have been validated as a reliable alternative to fractional flow reserve (FFR). However, a discordance between FFR and NHPRs is observed in 20-25% of cases. The aim of this study is to evaluate predictors of discordance between FFR and diastolic Pressure ratio (dPR).

METHODS

PREDICT is a retrospective, single center, investigator-initiated study including 813 patients (1092vessels) who underwent FFR assessment of intermediate coronary lesions (angiographic 30%-80% stenosis). dPR was calculated using individual pressure waveforms and dedicated software. Clinical, angiographic and hemodynamic variables were compared between patients with concordant and discordant FFR and dPR values.

RESULTS

Median age was 65 (IQR:59-73) years and 70% were male. Hemodynamically significant lesions, as defined by FFR ≤ 0.80, and dPR ≤ 0.89, were identified in 29.6% and 30.3% of cases, respectively. Overall, FFR and dPR values were discordant in 22.1% patients (17.4% of the vessels). Discordance was related to FFR+/dPR- and FFR-/dPR + in 11.8% and 10.3% of patients, respectively.In case of FFR-dPR discordance, a higher prevalence of left anterior descending arteries lesions was observed (70.5% vs. 53.1%, p < 0.001) and mean values of both FFR and dPR were significantly lower (FFR 0.81 ± 0.05 vs 0.85 ± 0.08, p < 0.001, and dPR 0.89 ± 0.04 vs 0.92 ± 0.08,p < 0.001) as compared to vessels with FFR and dPR concordance. Following multivariable adjustment, dPR delta (defined as the absolute difference between measured dPR to the cut-off value of 0.89) turned out to be the only independent predictor of discordance (OR = 0.74, 95% CI 0.68-0.79, p < 0.001).

CONCLUSION

Our study suggests that FFR-to-dPR discordance occurs in approximately one-fifth of patients. Absolute dPR delta appears to be the only independent predictor of discordance.