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Prevalence of microvascular disease in patients with significant coronary artery disease
J Qian1, J Ge, D Baumgart
1Department of Cardiology, Zhongshan Hospital, Shanghai Medical University, P. R. China.
Insights
Coronary flow velocity reserve (CFVR) improved after angioplasty, but microvascular dysfunction persisted in many patients. This study investigated CFVR changes and prevalence of microvascular dysfunction post-intervention.
Area of Science:
- Cardiology
- Vascular Physiology
Background:
- Coronary flow velocity reserve (CFVR) is crucial for assessing epicardial stenosis and post-intervention function.
- Discrepancies exist regarding acute CFVR changes immediately after coronary interventions.
Purpose of the Study:
- To investigate the prevalence of microvascular dysfunction in patients with significant coronary artery disease.
- To evaluate acute changes in CFVR following percutaneous transluminal coronary angioplasty (PTCA) and stenting.
Main Methods:
- Intracoronary Doppler flow measurements were performed in 212 patients with significant coronary artery disease.
- Adenosine was used to induce hyperemia, and CFVR was calculated as the ratio of hyperemic to baseline average peak velocities.
- Measurements were taken before and after PTCA or stenting.
Main Results:
- Successful PTCA and stenting significantly improved CFVR (p < 0.001).
- However, reduced CFVR (< 3.0) persisted in 61.3% of PTCA patients and 66.7% of stented patients.
- Microvascular dysfunction (CFVR < 3.0) was also prevalent in 45.9% of reference vessels in patients with single-vessel disease.
Conclusions:
- Successful coronary angioplasty significantly enhances coronary flow velocity and reserve.
- A substantial proportion of patients exhibit microvascular dysfunction, both in treated vessels and normal reference vessels, after intervention.
Abstract:
Coronary flow velocity reserve (CFVR) measurement using intracoronary Doppler techniques has been increasing accepted for the assessment of physiological significance of epicardial stenosis and the functional changes after coronary interventions. However, large discrepancy exists concerning the acute changes of CFVR immediately after intervention. The purpose of this study was to investigate the prevalence of microvascular dysfunction in patients with significant coronary artery disease. Intracoronary Doppler flow measurements were performed in a total of 212 patients who underwent coronary interventions because of significant epicardial stenosis using 0.014" Doppler flow wire (Cardiometrics, Inc, Mountain View, CA). Intracoronary bolus injection of adenosine (12 micrograms for the right coronary and 18 micrograms for the left coronary arteries) was used to induce hyperemic reaction. CFVR was registered as the ratio of average peak velocity during hyperemia (hAPV) to at baseline (bAPV). Successful coronary interventions either by percutaneous transluminal coronary balloon angioplasty (PTCA) or by stenting could significantly improve the CFVR. In 80 patients with PTCA, the bAPV elevated from 16.6 +/- 2.1 cm/s to 20.6 +/- 13.4 cm/s and hAPV from 30.1 +/- 15.9 cm/s to 45.2 +/- 17.7 cm/s (both p < 0.001) with PTCA and the CFVR increased from 1.94 +/- 0.78 to 2.58 +/- 0.87 correspondingly (p < 0.001). Significant elevation of coronary flow parameters were also found in 132 patients with subsequent stent implantation (bAPV from 15.3 +/- 6.7 cm/s to 18.7 +/- 9.1 cm/s, hAPV from 28.7 +/- 14.4 cm/s to 44.3 +/- 17.7 cm/s and CFVR from 1.90 +/- 0.70 to 2.59 +/- 0.87, all p < 0.001). Reduction of CFVR (< 3.0) after intervention still existed in 46 (61.3%) of 80 patients after PTCA and 88 (66.7%) of 132 patients after stenting. Moreover, CFVR < 3.0 were found in 50 (45.9%) of 109 reference vessels in patients with single vessel disease. Significant improvement of coronary flow velocity and coronary flow velocity reserve could be obtained after successful angioplasty. However, microvascualr dysfunction existed in a large proportion of patients either in normal reference vessels or in target vessels after interventions.