CLINICAL TRIAL
JOURNAL ARTICLE
MULTICENTER STUDY
RESEARCH SUPPORT, NON-U.S. GOV'T
Add like
Add dislike
Add to saved papers

Integrated physiologic assessment of ischemic heart disease in real-world practice using index of microcirculatory resistance and fractional flow reserve: insights from the International Index of Microcirculatory Resistance Registry.

BACKGROUND: The index of microcirculatory resistance (IMR) is a quantitative and specific index for coronary microcirculation. However, the distribution and determinants of IMR have not been fully investigated in patients with ischemic heart disease (IHD).

METHODS AND RESULTS: Consecutive patients who underwent elective measurement of both fractional flow reserve (FFR) and IMR were enrolled from 8 centers in 5 countries. Patients with acute myocardial infarction were excluded. To adjust for the influence of collateral flow, IMR values were corrected with Yong's formula (IMRcorr). High IMR was defined as greater than the 75th percentile in each of the major coronary arteries. FFR≤0.80 was defined as an ischemic value. 1096 patients with 1452 coronary arteries were analyzed (mean age 61.1, male 71.2%). Mean FFR was 0.84 and median IMRcorr was 16.6 U (Q1, Q3 12.4 U, 23.0 U). There was no correlation between IMRcorr and FFR values (r=0.01, P=0.62), and the categorical agreement of FFR and IMRcorr was low (kappa value=-0.04, P=0.10). There was no correlation between IMRcorr and angiographic % diameter stenosis (r=-0.03, P=0.25). Determinants of high IMR were previous myocardial infarction (odds ratio [OR] 2.16, 95% confidence interval [CI] 1.24-3.74, P=0.01), right coronary artery (OR 2.09, 95% CI 1.54-2.84, P<0.01), female (OR 1.67, 95% CI 1.18-2.38, P<0.01), and obesity (OR 1.80, 95% CI 1.31-2.49, P<0.01). Determinants of FFR ≤0.80 were left anterior descending coronary artery (OR 4.31, 95% CI 2.92-6.36, P<0.01), angiographic diameter stenosis ≥50% (OR 5.16, 95% CI 3.66-7.28, P<0.01), male (OR 2.15, 95% CI 1.38-3.35, P<0.01), and age (per 10 years, OR 1.21, 95% CI 1.01-1.46, P=0.04).

CONCLUSIONS: IMR showed no correlation with FFR and angiographic lesion severity, and the predictors of high IMR value were different from those for ischemic FFR value. Therefore, integration of IMR into FFR measurement may provide additional insights regarding the relative contribution of macro- and microvascular disease in patients with ischemic heart disease.

CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT02186093.

Full text links

We have located links that may give you full text access.
Can't access the paper?
Try logging in through your university/institutional subscription. For a smoother one-click institutional access experience, please use our mobile app.

For the best experience, use the Read mobile app

Mobile app image

Get seemless 1-tap access through your institution/university

For the best experience, use the Read mobile app

All material on this website is protected by copyright, Copyright © 1994-2024 by WebMD LLC.
This website also contains material copyrighted by 3rd parties.

By using this service, you agree to our terms of use and privacy policy.

Your Privacy Choices Toggle icon

You can now claim free CME credits for this literature searchClaim now

Get seemless 1-tap access through your institution/university

For the best experience, use the Read mobile app