Impaired Coronary Flow Reserve as a Marker of Microvascular Dysfunction to Predict Long-Term Cardiovascular Outcomes, Acute Coronary Syndrome and the Development of Heart Failure

Abstract

Background:In the absence of obstructive coronary narrowing, impaired coronary flow reserve (CFR) represents coronary microvascular dysfunction. Transthoracic Doppler echocardiography (TTDE) allows non-invasive measurement of CFR in the left anterior descending (LAD) artery. This study aimed to assess the prognostic value of TTDEderived CFR (as a marker of microvascular function) in predicting long-term cardiovascular events, acute coronary syndrome (ACS) events, and the development of heart failure (HF). Methods and Results:This study consisted of 272 patients with coronary artery disease not involving obstructive narrowing (≥50%) in the LAD. Patients underwent TTDE examination for CFR measurement in the LAD. During the follow-up period of 4.0±1.9 years, 32 patients (12%) had cardiovascular events. Cox proportional hazard analysis identified lower CFR as an independent risk factor of cardiovascular events (P<0.001), ACS events (P=0.008), and HF development (P=0.003). A CFR less than 2.4 was the best cut-off value for predicting all events (area under the curve=0.82). CFR excellently predicted the development of HF (area under the curve=0.95), but not ACS events (area under the curve=0.67). Conclusions:This TTDE study demonstrated that CFR was a significant and independent determinant of long-term cardiovascular events, ACS events and HF in patients with coronary artery disease. A CFR greater than 2.0 was not suitable to predict a favorable long-term outcome, even in the absence of obstructive coronary narrowing. (Circ J 2012; 76: 1958 - 1964

Coronary flow velocity reserve predicts survival in non-diabetic patients

“…The prognostic role of echocardiography-derived CFR is widely examined in patients with suspected or known CAD [2][3][4][7][8][9][16][17][18][19][20][21][22][23][24][25]. CFR has a prognostic significance on cardiovascular outcome not only in patients with significant CAD [16], but also in subjects with intermediate (50 to 75%) LAD stenosis [17,18] or angiographically normal or near-normal coronary arteries [4,8,19].…”

“…CFR has a prognostic significance on cardiovascular outcome not only in patients with significant CAD [16], but also in subjects with intermediate (50 to 75%) LAD stenosis [17,18] or angiographically normal or near-normal coronary arteries [4,8,19]. Sicari et al found that ongoing antiischemic therapy at the time of testing does not modulate the prognostic value of CFR [20].…”

Reserve of Coronary Flow Deserves Predictor of Cardiovascular Events

“…1, 5 In this issue of the Journal, however, Nakanishi K et al reevaluate the widely-accepted single cut-off value of TTDEderived CFR ≤2.0 from the standpoint of predicting favorable long-term cardiovascular outcomes. 9 They measured the TTDEderived CFR in 272 patients with coronary artery disease without obstructive narrowing (≥50%) in the left anterior descending artery and evaluated its predictive value for future cardiovascular events. During the follow-up period of 4.0±1.9 years, cardiovascular events occurred in 32 (11.8%) patients, including acute coronary syndrome (ACS) in 17 patients and heart failure (HF) in 15 patients.…”

Protective Effect of Pre-Infarction Angina on Microvascular Obstruction After Primary Percutaneous Coronary Intervention Is Blunted in Humans by Cardiovascular Risk Factors

“…[16][17][18][19][20][21][22][23] Interestingly, previous studies have shown a reduction "in vivo" of the MVO rate in patients experiencing PIA. [24][25][26] Of note, although it is already known that cardiovascular risk factors (CRFs) may limit the protective effects of IP in human models, 27-30 it is still unknown whether they may also limit the protective effect of PIA on MVO.…”