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Published on: April 25, 2014
Evaluation of mid vs distal left anterior descending artery measures in coronary physiology assessment
Fazal Dalal1, Yissela Escobedo2, Jose Emilio Exaire2
1Department of Internal Medicine, Baylor Scott and White, Temple, TX, United States of America.
Insights
Coronary physiology assessment (CPA) wire positioning impacts results. Deeper placement in the left anterior descending artery (LAD) leads to lower coronary flow reserve (CFR) and higher index of microcirculatory resistance (IMR) in angina patients.
Area of Science:
- Cardiology
- Interventional Cardiology
- Diagnostic Imaging
Background:
- Angina with no obstructive coronary artery disease (ANOCA) affects ~40% of patients undergoing coronary angiography.
- Coronary physiology assessment (CPA) is guideline-recommended for diagnosing ANOCA.
- Optimal wire/sensor positioning for CPA via bolus coronary thermodilution is not established.
Purpose of the Study:
- To investigate the impact of wire positioning on CPA outcomes.
- To compare coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) at different positions in the left anterior descending artery (LAD).
Main Methods:
- Retrospective review of CPA data and demographics in ANOCA patients.
- Evaluation of CFR and IMR with maximal hyperemia in the mid-LAD (4-6 cm) versus distal 2/3 LAD.
- Statistical analysis using linear regression, paired t-test, and Bland-Altman analysis.
Main Results:
- 42 patients (72% female, median age 60.5) were assessed.
- Lower median CFR (2.71 vs 3.55) and higher median IMR (22.27 vs 16.41 mmHg*s) were observed in the distal LAD compared to the mid-LAD (p=0.01* for both).
- Distal pressures showed no significant difference, but resting and hyperemic transit times differed significantly between mid and distal LAD segments.
Conclusions:
- CPA outcomes (CFR, IMR) are significantly influenced by wire positioning.
- Deeper wire placement in the LAD results in lower CFR and higher IMR values.
- Standardized wire positioning is crucial for accurate CPA interpretation in ANOCA.
Background:
Angina with no obstructive coronary artery disease (ANOCA) occurs in approximately 40 % of patients who undergo diagnostic coronary angiography for symptoms of angina. Coronary physiology assessment (CPA) is a guideline proven method to assess and diagnose these patients for an effective treatment strategy. There is currently no data regarding optimal wire or sensor position for CPA using bolus coronary thermodilution.
Methods:
We reviewed CPA data and baseline demographics in a cohort of patients who underwent CPA for ANOCA. We evaluated coronary flow reserve (CFR) and index of microcirculatory resistance (IMR) in patients whereby maximal hyperemia was obtained in the middle portion (4-6 cm) of the left anterior descending artery (LAD) and the distal 2/3 of the LAD using linear regression, Paired t-test, and Bland-Altman analysis.
Results:
We assessed 42 patients with a median age of 60.5 [50,67] and 72 % female. Median CFR in the mid-LAD was 3.55 [2.54, 4.58] and 2.71 [2.0,3.88; p = 0.01*] in the distal segment. Median IMR in the mid-LAD was 16.41 mmHg*s [10.60, 22.07] and 22.27 mmHg*s [14.79,37.0] in the distal segment (p = 0.01*). Average distal pressures (Pd) were 77.14 mmHg in the mid and 75.31 mmHg in the distal LAD (p = 0.57) with differing resting (0.75 s vs 0.97 s, p = 0.01*) and hyperemic (0.25 vs 0.40, p = 0.003*) transit times in the mid vs distal vessel, respectively.
Conclusions:
Here we demonstrate that CPA outcomes including CFR and IMR values are dependent upon wire positioning with deeper wire position resulting in lower CFR and higher IMR values.
