Archive for the ‘Fractional flow reserve’ Category

Metaregression of FFR trials: clinical end-points.T

The paper here explores clinical end-point relationship with continuous FFR from FFR trials using metaregression.



Journal Club 12 September 2012

September 11, 2012 Leave a comment


Fractional Flow Reserve–Guided PCI versus Medical Therapy in Stable Coronary Disease





The preferred initial treatment for patients with stable coronary artery disease is the
best available medical therapy. We hypothesized that in patients with functionally
significant stenoses, as determined by measurement of fractional flow reserve (FFR),
percutaneous coronary intervention (PCI) plus the best available medical therapy
would be superior to the best available medical therapy alone.


In patients with stable coronary artery disease for whom PCI was being considered,
we assessed all stenoses by measuring FFR. Patients in whom at least one stenosis
was functionally significant (FFR, .0.80) were randomly assigned to FFR-guided
PCI plus the best available medical therapy (PCI group) or the best available medical
therapy alone (medical-therapy group). Patients in whom all stenoses had an FFR of
more than 0.80 were entered into a registry and received the best available medical
therapy. The primary end point was a composite of death, myocardial infarction, or
urgent revascularization.


Recruitment was halted prematurely after enrollment of 1220 patients (888 who
underwent randomization and 332 enrolled in the registry) because of a significant
between-group difference in the percentage of patients who had a primary endpoint
event: 4.3% in the PCI group and 12.7% in the medical-therapy group (hazard
ratio with PCI, 0.32; 95% confidence interval [CI], 0.19 to 0.53; P<0.001). The difference
was driven by a lower rate of urgent revascularization in the PCI group than
in the medical-therapy group (1.6% vs. 11.1%; hazard ratio, 0.13; 95% CI, 0.06 to 0.30;
P<0.001); in particular, in the PCI group, fewer urgent revascularizations were triggered
by a myocardial infarction or evidence of ischemia on electrocardiography
(hazard ratio, 0.13; 95% CI, 0.04 to 0.43; P<0.001). Among patients in the registry,
3.0% had a primary end-point event.


In patients with stable coronary artery disease and functionally significant stenoses,
FFR-guided PCI plus the best available medical therapy, as compared with the best
available medical therapy alone, decreased the need for urgent revascularization. In
patients without ischemia, the outcome appeared to be favorable with the best
available medical therapy alone.

Journal Club 9 May 2012


Morphometric Assessment of Coronary Stenosis Relevance With Optical Coherence Tomography
A Comparison With Fractional Flow Reserve and Intravascular Ultrasound




This paper compared optical coherence tomography and intravascular ultrasound anatomical measurements correlation with functional significance of intermediate coronary stenosis as assessed using fractional flow reserve


Patients scheduled for coronary angiography in whom 1 or more coronary stenoses with intermediate angiographic severity (40% to 70% diameter stenosis by quantitative coronary angiography [QCA])

Exclusions: Stenoses located in culprit vessels of acute coronary syndromes, serial stenoses, or diffuse coronary narrowings were excluded. Vessels providing circulation to previously infarct regions were also excluded. Other exclusion criteria were left main stenosis,
graft stenosis, contraindications to adenosine administration, hemodynamic instability, renal insufficiency, and anatomical
characteristics such as vessel tortuosity and severe calcification that do not allow the advancement of OCT and IVUS catheters.


Optical coherence tomography: minimal luminal area, minimal luminal diameter, area stenosis


Intravascular ultrasound: minimal luminal area, minimal luminal diameter, area stenosis


Correlation between the measures and FFR were determined.  Receiver operator characteristic curves were created and limits of agreement of the anatomical measures between IVUS and OCT were determined.


Angiographic stenosis severity was 50.9  8% diameter stenosis with 1.28  0.3 mm minimal lumen diameter.
FFR was 0.80 in 28 (45.9%) stenoses. An overall moderate diagnostic efficiency of OCT was found (area under
the curve [AUC]: 0.74; 95% confidence interval [CI]: 0.61 to 0.84), with sensitivity/specificity of 82%/63% associated
with an optimal cutoff value of 1.95 mm2. Comparison of the results in patients with simultaneous IVUS
and OCT imaging revealed no significant differences in the diagnostic efficiency of OCT (AUC: 0.70; 95% CI: 0.55
to 0.83) and IVUS (AUC. 0.63; 95% CI: 0.47 to 0.77; p  0.19). Sensitivity/specificity for IVUS was 67%/65% for
an optimal cutoff value of 2.36 mm2. In the subgroup of small vessels (reference diameter 3 mm) OCT
showed a significantly better diagnostic efficiency (AUC: 0.77; 95% CI: 0.60 to 0.89) than IVUS (AUC: 0.63; 95%
CI: 0.46 to 0.78) to identify functionally significant stenoses (p  0.04).

See also this post for further material.

Coronary stenosis measurement

March 19, 2012 3 comments