To test the usefulness of non-invasive coronary flow reserve (CFR) by transthoracic Doppler echocardiography by comparison to invasive fractional flow reserve (FFR) and instantaneous wave-free ratio ...(IFR), a new vasodilator-free index of coronary stenosis severity, in patients with left anterior descending artery (LAD) stenosis of intermediate severity (IS) and stable coronary artery disease. 94 consecutive patients (mean age 68 ± 10 years) with angiographic LAD stenosis of IS (50–70 % diameter stenosis), were prospectively studied. IFR was calculated as a trans-lesion pressure ratio during the wave-free period in diastole; FFR as distal pressure divided by mean aortic pressure during maximal hyperemia (using 180 μg intracoronary adenosine); and CFR as hyperemic peak LAD flow velocity divided by baseline flow velocity using intravenous adenosine (140 μg/kg/min over 2 min). The mean values of IFR, FFR, and CFR were 0.88 ± 0.07, 0.81 ± 0.09, and 2.4 ± 0.6 respectively. A significant correlation was found between CFR and FFR (r = 0. 68), FFR and IFR (r = 0.6), and between CFR and IFR (r = 0.5) (all, p < 0.01). Using a ROC curve analysis, the best cut-off to detect a significant lesion based on FFR assessment (FFR ≤ 0.8, n = 31) was IFR ≤ 0.88 with a sensitivity (Se) of 74 %, specificity (Sp) of 73 %, AUC 0.81 ± 0.04, accuracy 72 %; and CFR ≤ 2 with a Se = 77 %, Sp = 89 %, AUC 0.88 ± 0.04, accuracy 85 % (all, p < 0.001). In stable patients with LAD stenosis of IS, non-invasive CFR is a useful tool to detect a significant lesion based on FFR. Furthermore, there was a better correlation between CFR and FFR than between CFR and IFR, and a trend to a better diagnostic performance for CFR versus IFR.
Assessment of the functional significance of left anterior descending coronary artery (LAD) stenosis of intermediate severity is challenging and often based on fractional flow reserve (FFR). The ...instantaneous wave-free ratio (IFR), a new vasodilator-free index of coronary stenosis severity, and non-invasive coronary flow reserve (CFR) by transthoracic Doppler echocardiography are also potentially useful. A direct comparison of FFR, IFR, and non-invasive CFR has never been performed. Our objective was to test the usefulness of non-invasive CFR by comparison to invasive FFR and IFR in patients with LAD stenosis of angiographic intermediate severity and stable coronary artery disease.
Ninety-four stable consecutive patients (mean age, 68±10years; 19 women) with angiographic proximal or mid LAD stenosis of intermediate severity (40–70% diameter stenosis on quantitative coronary angiography), were prospectively studied. They underwent IFR that was calculated as a trans-lesion pressure ratio during a specific period of baseline diastole, FFR with intracoronary bolus adenosine (180μg), and CFR using intravenous adenosine (140μg/kg/min over 2min) in the distal part of the LAD, the same day. CFR was defined as hyperemic peak diastolic LAD flow velocity divided by baseline flow velocity and FFR as distal pressure divided by mean aortic pressure during maximal hyperemia.
The mean values of IFR, FFR, and CFR were 0.88±0.07, 0.81±0.09, and 2.4±0.6 respectively. A significant correlation was found between CFR and FFR (R=0.63, curvilinear relationship), FFR and IFR (R=0.6, linear relationship), and between CFR and IFR (R=0.5) (all, P<0.01). Using a ROC curve analysis, the best cut-off to detect a significant lesion based on FFR assessment (FFR≤0.8, N=31) was IFR≤0.88 with a sensitivity (Se) of 74%, specificity (Sp) of 73%, AUC 0.81±0.04; and CFR≤2 with a Se=77%, Sp=89%, AUC 0.88±0.04, (all, P<0.001). Based on these cut-offs, discordant results between CFR and FFR were observed in 14 cases (agreement 85%), between CFR and IFR in 26 cases (agreement 72%), and between IFR and FFR in 26 cases (agreement 72%).
In stable patients with LAD stenosis of intermediate severity, non-invasive CFR is a useful tool to detect a significant lesion based on FFR. Furthermore, there was a better correlation and agreement between CFR and FFR than with IFR.
Takotsubo cardiomyopathy (TTC) is a distinct clinical entity characterized by the presence of transient left ventricular (LV) wall motion abnormalities without significant culprit obstructive ...coronary artery disease. Whether left atrial (LA) function is also transiently impaired in this setting is unclear.
To assess prospectively the LA function by two-dimensional longitudinal strain at the acute phase of TTC and after recovery.
Thirty-seven consecutive patients satisfying the criteria for typical TTC (mean age 79±9 years, 34 women) underwent transthoracic-Doppler echocardiography at the acute phase and at follow-up (on average 30 days later), including the measurement of the LA peak systolic longitudinal strain (LAS) which was measured as a mean of maximal strain from the 4–2 chamber views conducted using a dedicated software package, using R-R gating. A control group of 8 patients (76±7 years, 7 women) without overt cardiovascular disease served as a comparative group.
In the TTC group, LAS improved significantly between the two examinations from 15.5±6% to 27±9% (P<0.01) whereas LA volume did not change (from 30±13 to 29±12ml/m2, P=NS). By comparison, in the control group LAS was 30±3% (P<0.01 vs. TTC acute phase, P=NS vs. TTC follow-up) and LA volume/m2 was 28±3.5 (P=NS vs. TTC all phases). The change of LAS in the TTC group (median improvement 62%, 25th-75th percentiles: 18–129%) was significantly correlated to the change of the global LV longitudinal strain (r= −0.41, P=0.01).
Serial measurements of LAS suggests transient impairment of LA function (reservoir) at the acute phase of TTC. Furthermore, the improvement of LAS parallel the dynamic improvement of LV systolic function.
Left atrial (LA) function is increasingly used to assess cardiovascular diseases.
We tested the relationship between LA distensibility (Lad), LA strain (Las) and left ventricular dysfunction and ...prognosis in aortic stenosis (AS).
Transthoracic Doppler echocardiography was performed prospectively in 98 consecutive patients with AS (63 with severe, 35 with moderate AS, mean age 77±10 years, 49% women, mean aortic valve area 0.5±0.15cm2, mean LVEF 63±13%). LA volume was calculated by the area-length method in apical four-and two-chamber views, at two points: immediately before mitral valve opening (Vol max) and at mitral valve closure (Volmin). LA distensibility was defined as (Vol max−Vol min)×100%/Vol min. Las (mean of maximal strain from the 4-2-3 chamber views) was conducted using a dedicated software package, using R-R gating. The end-point was hospitalisation for heart failure and death from any cause.
Las, Lad, and LA vol/m2 were significantly correlated to E/A, E/e’, and pulmonary artery systolic pressure (all, P<0.05). However, Lad and Las but not LA vol/m2 were significantly correlated to comorbidities index (Charlson, Euroscore), LVEF, stroke volume/m2, as well as to peak aortic jet velocity (all, P<0.05). At a median follow-up of 25 months, 48 patients had an event. Las, Lad, LA volume/m2, as well as Charlson index, diabetes, and DTI parameters were associated to events (all, P<0.05). In multivariate analysis, Lad, Las, (all, P<0.01) and Charlson index (P<0.05) remained independently associated to events. Using a ROC curve analysis, a LAd<70% (AUC=0. 76±0.05, P<0.001), and Las<17% (AUC=0.73±0.05) were the best cut-off to predict an event at follow-up.
In patients with moderate to severe AS, Lad and LAs are associated with LV diastolic and systolic dysfunction, AS severity, and are independently linked to events.