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Prognosis of CT-derived Fractional Flow Reserve in the Prediction of Clinical Outcomes.

ABSTRACT:

Purpose

To examine the prognostic implication of fractional flow reserve (FFR) derived from coronary CT (FFR_CT) in routine clinical practice.

Materials and methods

Patients referred for FFR_CT analysis at a single center between October 2015 and June 2017 were retrospectively included and followed up for rates of invasive angiography and clinical events. Two hundred seven patients underwent successful FFR_CT analysis with seven lost to follow-up, leaving 200 (mean age ± standard deviation, 62.4 years ± 10.0; 49 [24.5%] women) patients for analysis. At coronary CT angiography, patients were categorized as having significant stenosis (SS) in the presence of a diameter stenosis greater than or equal to 50% (hereafter, SS positive) and flow limitation in the presence of a postlesion (that is, FFR_CT measured 2 cm to the distal aspect of the lesion) FFR_CT less than 0.80 (hereafter, FFR_CT positive). Vessel-oriented clinical events (VOCEs) were defined as vessel-related late revascularization (>90 days), myocardial infarction, and cardiac mortality.

Results

At CT angiography, 130 (65%) studies were SS positive and 63 (31.5%) were FFR_CT positive. At median follow-up of 477 days (range, 252-859 days), there were 26 VOCE end points in 22 patients: 22 revascularizations and four nonfatal myocardial infarctions. VOCE end points occurred in zero of 58 (0%) of SS-negative and FFR_CT negative patients, in eight of 79 (10.1%) of SS-positive and FFR_CT-negative patients, in zero of 12 (0%) of SS-negative and FFR_CT-positive patients, and in 18 of 51 (35.3%) of SS-positive and FFR_CT-positive patients (log-rank χ² = 30.1; P < .001). At multivariable Cox regression, both FFR_CT (hazard ratio per 0.1 decrease, 1.54 [95% confidence interval: 1.1, 2.2] P = .013) and stenosis (hazard ratio per unit increase, 2.16 [95% confidence interval: 1.25, 3.72] P = .006) were independently associated with VOCE.

Conclusion

Stenosis and FFR_CT are independent predictors of intermediate-term outcomes. In the absence of a stenosis greater than 50%, a positive FFR_CT result is not associated with an increased intermediate risk.© RSNA, 2019Supplemental material is available for this article.See also commentary by Fairbairn and Bull in this issue.

SUBMITTER: McNabney CG

PROVIDER: S-EPMC7970101 | biostudies-literature |

REPOSITORIES: biostudies-literature

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