FFR- and IVUS-Guided PCI Do Not Reduce
Mortality Long-Term: Observational Study
LONDON, UK — The use of
fractional flow reserve (FFR) or intravascular ultrasound (IVUS) during PCI is
not associated with improved long-term mortality rates when compared with
standard angiography-guided PCI, according to a new observational study[1].
The results are based on an
analysis of 41 688 patients with stable angina and non-ST-segment-elevation MI
(NSTEMI) included in the Pan-London (United Kingdom) PCI Registry.
Compared with conventional PCI, there was no statistically significant
difference in mortality among those treated with FFR- and IVUS-guided PCI after
a median of 3.3 years.
"It is perhaps too
optimistic to expect a survival advantage from the use of a purely diagnostic
procedure," write Dr Georg Fröhlich (University College London
Hospital, UK) and colleagues in the August 2014 issue of the Journal
of American Medical Association: Internal Medicine. "This is
particularly true in patients with stable coronary artery disease, for whom PCI
has never demonstrated a clear survival benefit."
Commenting on the results for heartwire , Dr Sanjit Jolly (McMaster
University, Hamilton, ON) said the mortality rates observed in the registry are
very low, at less than 1%. He echoed the sentiment of the researchers in that
there was never any real belief that FFR-guided procedures would confer a
survival advantage over conventional angiographic PCI.
In the St Jude Medical-sponsored FAME II trial, stable patients who got a stent to treat a
functionally significant coronary lesion were less likely to need an urgent
reintervention than those treated with medical therapy alone, but the
FFR-guided approach did not show a survival benefit. Similarly, FAME showed a benefit of FFR on the primary end point of
major adverse cardiovascular events (MACE), a benefit that was largely driven
by the need for repeat revascularizations.
"FFR is a clinical tool to
help decide whether a lesion is significant," said Jolly, who is not
connected to the study. "Potentially, you would avoid performing PCI when
it's unnecessary and do PCI when you're unsure if it's appropriate."
The American Heart Association
(AHA) recommends FFR be used for a hemodynamic assessment in patients with
stable angina if the coronary lesion is considered of intermediate severity
(class IIa). The AHA guidelines also recommend the use of IVUS to assess
intermediate lesions in the left main artery (class IIa).
The Data From the PCI Registry
In the UK PCI Registry, 2767
patients underwent FFR-guided PCI, and IVUS was used in 1831 patients. After
adjustment for multiple variables, the FFR-guided mortality rate after 3.3
years was not significantly different from that of angiography-guided PCI
(hazard ratio 0.88; 95% CI 0.67–1.16). Similarly, IVUS-guided PCI did not confer
a mortality benefit compared with angiography-guided PCI (hazard ratio 1.39;
95% CI 1.09-1.78). A propensity-matched analysis showed similar results.
Complications and Other Outcome
Measures
|
Outcome
|
Angiography (n=37 090)
|
FFR (n=2767)
|
IVUS (n=1831)
|
p
|
|
Stents implanted (n)
|
1.7
|
1.1
|
1.2
|
<0 .001="" o:p="">
|
Procedural complications
0.009
Side-branch occlusion (%)
0.4
0.2
0.4
—
Coronary dissection (%)
1.2
0.6
1.8
—
Coronary perforation (%)
0.2
0.1
0.3
—
No reflow (%)
0.4
0.1
0.3
—
Individuals in the FFR group
received significantly fewer implanted stents than those treated with IVUS and
conventional PCI. "These data are in line with results from previous
randomized trials suggesting that FFR-guided PCI may have a stent-sparing
effect, but this did not translate into a survival benefit," write the
investigators.
