Flow velocity and predictors of a suboptimal coronary flow velocity reserve after coronary balloon angioplasty

Aims: This study was conducted to analyse flow velocity parameters and predictors of a suboptimal coronary flow reserve (<2.5) following balloon angioplasty. Methods: Two hundred and twenty-five patients underwent sequential intracoronary Doppler as part of the DEBATE I study. Of these, 183, with complete angiography and Doppler at the 6-month follow-up, were included. Univariate and multivariate logistic analysis was performed to identify independent predictors of post-procedural suboptimal coronary flow reserve, defined as coronary flow reserve <2.5. Results: Forty-eight per cent (n=88) of the patients achieved a suboptimal coronary flow reserve. These patients had higher baseline velocities (cm.s ^-1) before balloon angioplasty (18 ± 9 vs 14 ± 6, P=0.004), after balloon angioplasty (22 ± 11 vs 14 ± 5, P<0.001) and at follow-up (19 ± 9 vs 16 ± 6, P=0.011) than the optimal coronary flow reserve group. Although the suboptimal group had lower hyperaemic velocities (cm.s ^-1) after balloon angioplasty than the optimal group (42 ± 17 vs 49 = 16, P=0.008), these velocities became similar at follow-up. Increasing age (odds ratio, OR 1.071, P=0.0002), female gender (OR 2.52, P=0.014) and increasing pre-procedural baseline average peak velocities (OR 1.056, P<0.001) were found to be independent predictors of a suboptimal coronary flow reserve following balloon angioplasty. Conclusion: A suboptimal coronary flow reserve was associated with (1) a chronically elevated baseline average peak velocity (2) a transient deficit in the hyperaemic average peak velocity (3) the elderly, and female gender.