Background. In the catheter laboratory there is a need for functional tests
validating the hemodynamic significance of coronary artery stenosis.
Objectives. It was the objective of our study to compare the long term card
iac event rate and the clinical symptoms in patients with reduced coronary
flow velocity reserve (CFVR) and standard PTCA with patients with normal CF
VR and deferred angioplasty.
Methods. Our study included 70 patients,vith intermediate coronary artery s
tenoses (13 f, 57 m; diameter stenosis >50%, <90%) and an indication for PT
CA due to stable angina pectoris and/or signs of ischemia in noninvasive st
ress tests. CFVR was measured distal to the lesion after intracoronary admi
nistration of adenosine using 0.014 inch Doppler-tipped guide wires.
Results. In 22 patients (31%), PTCA was deferred due to a CFVR greater than
or equal to 2.0 (non-PTCA group). In the remaining 48 patients (69%) mean
CFVR of 1.4 +/- 0.23 (p < 0.001) was measured (PTCA group). CFVR increased
to 2.0 +/- 0.51 after angioplasty. During follow-up (average 15 +/- 6.0 mon
ths), the following major adverse cardiac events (MACE) occurred: in the PT
CA group re-PTCA was performed in nine patients (18.8%) because of unstable
angina, five patients (10.4%) suffered an acute myocardial infarction (MI)
(two infarctions occurred during the angioplasty, three patients suffered
an infarction during follow-up), two patients (4.2%) needed blood transfusi
ons due to severe bleedings, two patients (4.2%) underwent bypass surgery a
nd one patient (2.1%) died. In the non PTCA group, angioplasty was necessar
y only in two cases (9.1%) during follow-up. We did not observe any MI in t
he non-PTCA group.
The overall rate of MACE was significantly lower in the non-PTCA group comp
ared to the PTCA group (9.1% vs. 33.3%, p < 0.01). However, only 40% of the
patients of the non-PTCA group were free of angina pectoris at stress, In
the PTCA group, 63% did not complain of any symptoms at follow up (p < 0.05
),
Conclusions. We conclude that determination of the CFVR is a valuable param
eter for stratifying the hemodynamic significance of coronary artery stenos
is. PTCA can safely be deferred in patients with significant coronary steno
sis but a CFVR greater than or equal to 2.0. The total rate of MACE at foll
ow up was below 10% among these patients. However, if PTCA was deferred the
number of patients who are free of angina is lower compared to those patie
nts who underwent angioplasty, (C) 1998 by the American College of Cardiolo
gy.