Coronary Flow Velocity Reserve during Dobutamine Stress Echocardiography

Abstract

Background A coronary flow velocity reserve (CFVR) ≥ 2 is adequate to infer a favorable prognosis or the absence of significant coronary artery disease. Objective To identify parameters which are relevant to obtain CFVR (adequate or inadequate) in the left anterior descending coronary artery (LAD) during dobutamine stress echocardiography (DSE). Methods 100 patients referred for detection of myocardial ischemia by DSE were evaluated; they were instructed to discontinue the use of β-blockers 72 hours prior to the test. CFVR was calculated as a ratio of the diastolic peak velocity (cm/s) (DPV) on DSE (DPV-DSE) to baseline DPV at rest (DPV-Rest). In group I, CFVR was < 2 and, in group II, CFVR was ≥ 2. The Fisher's exact test and Student's t test were used for the statistical analyses. P values < 0.05 were considered statistically significant. Results At rest, the time (in seconds) to obtain Doppler in LAD in groups I and II was not different (53±31 vs. 45±32; p=0.23). During DSE, LAD was recorded in 92 patients. Group I patients were older (65.9±9.3 vs. 61.2±10.8 years; p=0.04), had lower ejection fraction (61±10 vs. 66±6%; p=0.005), higher DPV-Rest (36.81±08 vs. 25.63 ± 06cm/s; p<0.0001) and lower CFVR (1.67 ± 0.24 vs. 2.53 ± 0.57; p<0.0001), but no difference was observed regarding DPVDSE (61.40±16 vs. 64.23±16cm/s; p=0.42). β-blocker discontinuation was associated with a 4-fold higher chance of a CFVR < 2 (OR= 4; 95% CI [1.171-13.63], p=0.027). Conclusion DPV-Rest was the main parameter to determine an adequate CFVR. β-blocker discontinuation was significantly associated with inadequate CFVR. The high feasibility and the time to record the LAD corroborate the use of this methodology.

Effect of adrenergic agonists on coronary blood flow: a laboratory study in healthy volunteers

“…In brief, CBVpeak was calculated as the peak diastolic velocity (average of 3 or more cardiac cycles) and VTI was calculated as the area under the entire diastolic blood flow profile of the highest quality image for a single cardiac cycle. This approach is consistent with other published reports (Saraste et al 2001;Meimoun et al 2006;Abreu et al 2014).…”

“…However, whether coronary adrenergic receptors play a major or minor role in maximal vasodilator responses (e.g., in response adenosine or dipyridamole) remains an unanswered question (Hodgson et al 1989;Meimoun et al 2006). Previous echocardiography studies have used either CBVpeak (Meimoun et al 2006;Abreu et al 2014) or VTI (Chammas et al 2007) to estimate change in coronary blood flow. The main difference between these two measures is that VTI takes into account diastolic time, a critical determinant of coronary blood flow (Heusch 2008), whereas CBVpeak does not and may therefore overestimate flow at increasing HR.…”

Prognostic Value of Coronary Flow Reserve Obtained on Dobutamine Stress Echocardiography and its Correlation with Target Heart Rate

“…This is a prospective observational study performed during two years in a population selected from the previous study by Abreu et al, 23 which has assessed CFVR during DSE.…”

“…The segmental contraction score index was calculated by dividing the points obtained by 16. 1 , 2 , 23 …”

“…Normal CFVR in the LAD can be obtained before (early) or after (late) submaximal target heart rate (HR) is reached. 20 , 23 Although the relevance of CFVR has been established, the meaning of normal CFVR obtained at the early stage of DSE has not been clarified. Thus, this study aimed at assessing the prognostic value of CFVR obtained in the LAD of patients with preserved LVEF (>50%) who completed DSE after reaching submaximal target HR.…”