Introduction and objectives. Coronary flow reserve
(CFR) is impaired not only in ischemic heart disease, but
also in cardiac diseases that may or may not course with
heart failure. The aim of the present study was to determine
if the severity of heart failure can influence CFR impairment.
Methods. Forty patients with non-ischemic heart disease
and heart failure were studied 41 times. Four groups
were established: 1. 10 patients in functional class III-IV;
2. 10 patients in functional class II not taking beta-blockers;
3. 11 patients in class II treated with carvedilol, and 4.
10 patients in class I. These patients had a history of heart
failure and systolic dysfunction. Myocardial blood flow
(MBF) was measured with positron emission tomography
(PET) and N-13 ammonia at rest (r) and during adenosine
triphosphate (ATP) infusion.
Results. MBF and CFR were significantly higher in
group 4 (1.95 ± 0.58 and 2.40 ± 0.95 ml/min/g) than in
group 1 (1.02 ± 0.52 and 1.46 ± 0.48 ml/min/g). CFR tended
to be higher in groups 2 (1.73 ± 0.72), and 3 (1.89 ±
0.75) vs group 1. No significant correlation was found between
CFR and the following variables: age, systolic blood
pressure, ventricular mass index, ventricular volume indexes,
and ejection fraction.
Conclusions. Coronary microvascular function is impaired
in non-ischemic heart failure, and the impairment is
related to functional class, regardless of the underlying
responsible heart disease
