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

Circ J. 2012;76(8):1958-64. doi: 10.1253/circj.cj-12-0245. Epub 2012 May 28.

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 TTDE-derived 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.

Publication types

  • Clinical Trial

MeSH terms

  • Acute Coronary Syndrome / diagnostic imaging
  • Acute Coronary Syndrome / physiopathology*
  • Aged
  • Aged, 80 and over
  • Coronary Circulation*
  • Echocardiography
  • Female
  • Heart Failure / diagnostic imaging
  • Heart Failure / physiopathology*
  • Humans
  • Male
  • Microcirculation*
  • Middle Aged
  • Predictive Value of Tests
  • Risk Factors